CACM	preliminary report international algebraic language
CACM	extraction of roots by repeated subtractions for digital computers
CACM	techniques department on matrix program schemes
CACM	glossary of computer engineering and programming terminology
CACM	two square root approximations
CACM	the use of computers in inspection procedures
CACM	glossary of computer engineering and programming terminology
CACM	on the equivalence and transformation of program schemes
CACM	proposal for an uncol
CACM	glossary of computer engineering and programming terminology
CACM	the problem of programming communication with changing machines a proposed solution part 2
CACM	error estimation in runge kutta procedures
CACM	glossary of computer engineering and programming terminology
CACM	the problem of programming communication with changing machines a proposed solution part 1
CACM	recursive curve fitting technique
CACM	secant modification of newtons method
CACM	on programming of arithmetic operations
CACM	simple automatic coding systems
CACM	glossary of computer engineering and programming terminology
CACM	accelerating convergence of iterative processes a technique is discussed which when applied to an iterative procedure for the solution of an equation accelerates the rate of convergence if the iteration converges and induces convergence if the iteration diverges an illustrative example is given
CACM	algebraic formulation of flow diagrams
CACM	unusual applications department  automatic implementation of computer logic
CACM	binary and truth function operations on a decimal computer with an extract command
CACM	an improved decimal redundancy check
CACM	general purpose programming systems
CACM	a subroutine method for calculating logarithms
CACM	note on empirical bounds for generating bessel functions
CACM	request for methods or programs
CACM	need for an algorithm
CACM	algorithm for analyzing logical statements to produce a truth function table
CACM	ibm 704 code nundrums
CACM	variable width tables with binary search facility
CACM	a programmed binary counter for the ibm type 650 calculator
CACM	tables for automatic computation
CACM	a machine method for square root computation
CACM	a queue network simulator for the ibm 650 and burroughs 220
CACM	impact of computer developments
CACM	a proposed interpretation in algol
CACM	the secant method for simultaneous nonlinear equations a procedure for the simultaneous solution of a system of not necessarily linear equations a generalization of the secant method for a single function of one variable is given
CACM	fingers or fists the choice of decimal or binary representation the binary number system offers many advantages over a decimal representation for a high performance general purpose computer the greater simplicity of a binary arithmetic unit and the greater compactness of binary numbers both contribute directly to arithmetic speed less obvious and perhaps more important is the way binary addressing and instruction formats can increase the overall performance binary addresses are also essential to certain powerful operations which are not practical with decimal instruction formats on the other hand decimal numbers are essential for communicating between man and the computer in applications requiring the processing of a large volume of inherently decimal input and output data the time for decimal binary conversion needed by a purely binary computer may be significant a slower decimal adder may take less time than a fast binary adder doing an addition and two conversions a careful review of the significance of decimal and binary addressing and both binary and decimal data arithmetic supplemented by efficient conversion instructions
CACM	some notes on computer research in eastern europe
CACM	a new method of computation of square roots without using division
CACM	a technique for handling macro instructions
CACM	runcible algebraic translation on a limited computer
CACM	flow outlining a substitute for flow charting
CACM	multiprogramming stretch feasibility considerations the tendency towards increased parallelism in computers is noted exploitation of this parallelism presents a number of new problems in machine design and in programming systems minimum requirements for successful concurrent execution of several independent problem programs are discussed these requirements are met in the stretch system by a carefully balanced combination of built in and programmed logic techniques are described which place the burden of the programmed logic on system programs supervisory program and compiler rather than on problem programs
CACM	russian visit to u s computers
CACM	shift register code for indexing applications in this communication the use of a shift register code with n 10 is described for calling 64 wireless telemetering stations in a fixed cyclical order a high degree of redundancy is used permitting a single error correcting code minimum distance three code with 64 10 bit code words to be employed as the station identification code embedding this in the shift register code with period 1023 permits the code to be employed without punctuation each of the telemetering station receivers simply putting received ones and zeros into a shift register each time the given code combination arises identifying the particular station barring for tuitous error combinations of very low probability it has been called the communication describes the properties and application of the code in some detail and the finding of the particular example to be employed on ural the soviet built drum computer donated to the indian statistical institute by the united nations technical aid administration untaa
CACM	scientific and business applications oracle curve plotter
CACM	statistical programs for the ibm 650 part ii
CACM	on the construction of micro flowcharts
CACM	an efficient method for generating uniformly distributed points on the surface on an n dimensional sphere corrigendum
CACM	recommendations of the share algol committee
CACM	sale a simple algebraic language for engineers
CACM	an algebraic translator
CACM	proposed standard flow chart symbols
CACM	j e i d a and its computer center
CACM	lem 1 small size general purpose digital computer using magnetic ferrite elements the paper examines some of the questions of development and construction of a general purpose digital computer using contactless magnetic ferrite and capacitive dezu long duration capacitive memory elements developed at the laboratory of electrical modeling vinityi an sssr under the supervision of professor l i gutenmacher
CACM	survey of progress and trend of development and use of automatic data processing in business and management control systems of the federal government as of december 1957 iii
CACM	the alpha vector transformation of a system of linear constraints
CACM	ibm 709 tape matrix compiler
CACM	multi dimensional least squares polynomial curve fitting
CACM	octal diagrams of binary conception and their applicability to computer design logic this paper dates back the genesis of binary conception circa 5000 years ago and octal diagrams about 4800 years ago as derived by the chinese ancients it analyzes the applicability of binary trinities of the octal diagrams to modern electronic digital computer design logic
CACM	remarks on algol and symbol manipulation
CACM	algol sub committee report   extensions
CACM	a proposal for a generalized card code for 256 characters
CACM	central european computers
CACM	the role of the university in computers data processing and related fields a study was made of university programs in the united states in the fields of computers data processing operations research and other closely related fields university policies organization administration faculties students researches curricula equipment and financing were investigated an integrated university program is recommended reflecting the conviction that many present activities related to computers will develop into disciplines and as such are the legitimate province of the university scholar details on a recommended graduate school of computer sciences are given
CACM	statistical programs for the ibm 650 part i a collection is given of brief descriptions of statistical programs now in use in university computing centers which have ibm 650s
CACM	construction of a set of test matrices this paper develops the equations and properties of a set of test matrices which are useful in the determination of the accuracy of routines for finding the inverse determinant and or eigenvalues of a matrix
CACM	proposal for a feasible programming system this paper proposes designing a programming facility itself involving a digital computer and a program which will assist the preparation of large scale real time programs this facility is to be capable of preparing programs for any of a variety of machines having characteristics similar to those of the facilitys computer one of the basic assumptions is that there will be enough random access storage available to avoid the necessity for segmenting a constructed program in any fashion other than a trivial one while this assumption is somewhat unrealistic it is intended to provide an opportunity to concentrate on the other aspects of program construction the programming system should stress the discovery in source program statements of as many errors as possible before attempting to construct an object program among the computer characteristics which are advocated are a program interrupt scheme a large set of characters and indirect addressing
CACM	an educational program in computing
CACM	a real time data assimilator
CACM	a high speed sorting procedure
CACM	parameter estimation for simple nonlinear models
CACM	binary conversion with fixed decimal precision of a decimal fraction
CACM	on gat and the construction of translators
CACM	remarks on the practical solution of characteristic value problems this paper is concerned with the practical solution of characteristic value problem for an ordinary differential equation it is at once apparent that sequential computers be they digital or analog solve initial value problems rather than boundary value problems and some mathematical process must be found to compensate for the machines inadequacy compensating for machine imperfection is of course the normal activity of the numerical analyst a number of other papers have applied particular devices to particular problems the purpose of this note is to establish a mathematical framework or model for these practical procedures and thus assist in the use and extension of the ideas in other particular problems
CACM	programming for a machine with an extended address calculational mechanism
CACM	a technique for computing critical rotational speeds of flexible shafts on an automatic computer
CACM	norc high speed printer
CACM	handling identifiers as internal symbols in language processors substitution of computer oriented symbols for programmer oriented symbols in language processors is examined and a feasible method for doing so is presented
CACM	a visit to computation centers in the soviet union
CACM	survey of progress and trend of development and use of automatic data processing in business and management control systems of the federal government as of december 1957 ii part 2 see ca590406
CACM	error analysis in floating point arithmetic
CACM	survey of progress and trend of development and use of automatic data processing in business and management control systems of the federal government as of december 1957
CACM	a note on a method for generating points uniformly on n dimensional spheres
CACM	an efficient method for generating uniformly distributed points on the surface of an n dimensional sphere
CACM	a routine to find the solution of simultaneous linear equations with polynomial coefficients
CACM	binary arithmetic for discretely variable word length in a serial computer
CACM	a mathematical procedure for machine division
CACM	a checklist of intelligence for programming systems a remarkable variation exists in the degree of sophistication of various programming systems a particular manifestation is the jungle of assorted devices for reproducing limited human decision procedures an attempt is made here to begin a systematic classification of the various devices for educating the computer to take over the decision making functions of one or many human operators both those that have been demonstrated feasible to date and those that are highly desirable for the future
CACM	from formulas to computer oriented language a technique is shown for enabling a computer to translate simple algebraic formulas into a three address computer code
CACM	an iterative method for fitting the logistic curve an iterative method is given for finding a logistic curve of best least squares fit to a set of two dimensional points
CACM	elimination of special functions from differential equations a set of ordinary differential equations which contains mathematical functions requiring the use of subroutines for numerical solution by electronic computer tabular data for numerical solution by hand calculation or function generators when analog methods are applied can sometimes be expanded to an equivalent set of equations which do not contain the functions this is practical if these functions satisfy sufficiently simple differential equations thus among those functions which can be eliminated by this procedure are the trigonometric inverse trigonometric exponential and many other transcendental functions
CACM	on computing radiation integrals the relative merit and cost of four ways of evaluating typical radiation integrals containing spherical bessel functions are investigated these methods are desk machine evaluation of a finite series integration of the appropriate differential equation by a reeves electronic analog computer and by a litton 40 ibm 704 computer results are generally applicable to equations separated from a helmholtz or wave equation
CACM	signal corps research and development on automatic programming of digital computers
CACM	the arithmetic translator compiler of the ibm fortran automatic coding system
CACM	possible modifications to the international algebraic language
CACM	recursive subscripting compilers and list types memories
CACM	nuclear reactor codes
CACM	a comparison of 650 programming methods
CACM	cope console operator proficiency examination each year electronic computers become more sophisticated and the programs they must process become more complex because of this dependence of those in computing on the skill and experience of operators is increasing at the same time selection and training of qualified operators grows more difficult to meet the need for a quick accurate uniform operator test and training aid the authors have developed cope console operator proficiency examination outlined below while this examination is programmed specifically for the ibm 705 model ii with two tape record coordinators similar programs could be developed for other computers
CACM	digital simulation of discrete flow systems the discrete flow systems discussed are characterized by the movement of randomly arriving items along interacting channels programing a digital computer to simulate such systems utilizes some techniques not common in other approaches to physical problems the principal portion of the paper is a discussion of two simulation studies that illustrate some of the programming problems involved one is of an extensive package handling plant with the objective being optimization of parameters such as storage capacities and processing rates in the other air traffic flow and control procedures are simulated to compare the effects of alternative control decisions
CACM	two methods for word inversion on the ibm 709
CACM	a method for overlapping and erasure of lists an important property of the newell shaw simon scheme for computer storage of lists is that data having multiple occurrences need not be stored at more than one place in the computer that is lists may be overlapped unfortunately overlapping poses a problem for subsequent erasure given a list that is no longer needed it is desired to erase just those parts that do not overlap other lists in lisp mccarthy employs an elegant but inefficient solution to the problem the present paper describes a general method which enables efficient erasure the method employs interspersed reference counts to describe the extent of the overlapping
CACM	multiple precision arithmetic
CACM	programmed error correction in project mercury
CACM	a note on approximating e x
CACM	fibonaccian searching
CACM	on programming the numerical solution of polynomial equations numerical techniques are presented for computing the roots of polynomial equations by applying the recommended scaling and inversion rules the basic bairstow and newton raphson iterative techniques can be applied with great reliability both a high degree of accuracy and rapid convergence are realized numerical examples are shown to illustrate the pitfalls and to show how these are circumvented by application of the recommended procedures
CACM	numerical solution of the polynomial equation algorithm 30
CACM	survey of coded character representation
CACM	survey of punched card codes
CACM	optimizers their structure
CACM	the sumador chino on a recent motor trip through mexico the writer came across on adding device which was referred to as a sumador chino chinese adder a survey of the more available literature on the history of mathematics and on instruments of calculation has uncovered no reference to such a device the purpose of this communication is to enlist the help of other members in bringing to light whatever may be known concerning the evolution and present status of the sumador chino
CACM	an estimation of the relative efficiency of two internal sorting methods
CACM	character scanning on the ibm 7070
CACM	note on eigenvalue computation
CACM	a simple technique for coding differential equations
CACM	over all computation control and labelling
CACM	least squares fitting of a great circle through points on a sphere
CACM	compilation for two computers with neliac neliac a compiler based on algol was developed at the u s navy electronics laboratory san diego california as a boot strap compiler for the remington rand univac countess computer this compiler was used to generate a version of itself which running as a countess program generated machine code for the control data corporation cdc 1604 all three versions of neliac accepted essentially identical input language
CACM	an algorithm for the assignment problem the assignment problem is formulated and briefly discussed an efficient algorithm for its solution is presented in algol code an empirical relation between solution time and the size of the problem is given based on extensive experiments carried out on a digital computer
CACM	polynomial transformer algorithm 29
CACM	least squares fit by orthogonal polynomials algorithm 28
CACM	assignment algorithm 27
CACM	rootfinder iii algorithm 26
CACM	rootfinder ii algorithm 15
CACM	real zeros of an arbitrary function algorithm 25
CACM	solution of tri diagonal linear equations algorithm 24
CACM	math sort algorithm 23
CACM	riccati bessel functions of first and second kind algorithm 22
CACM	bessel function for a set of integer orders algorithm 21
CACM	digital computers in universities iv
CACM	a note on the calculation of interest
CACM	evaluating numbers expressed as strings of english words
CACM	some thoughts on reconciling various character set proposals corrigenda
CACM	binomial coefficients algorithm 19
CACM	crout with pivoting algorithm 16
CACM	some thoughts on parallel processing
CACM	comments on a technique for counting ones
CACM	a list of computer systems programs for the ibm 650 datatron 205 and univac ss 80
CACM	do it by the numbers digital shorthand present communications systems transmit single characters in groups of coded pulses between simple terminal equipments since english words form only a sparse set of all possible alphabetic combinations present methods are inefficient when computer systems are substituted for these terminals using numeric representations of entire words or common phrases rather than character by character representations requires approximately one third of present transmission time this saving is reflected in overall costs other benefits accrue in code and language translation schemes provision is made for transmission of purely numeric and or binary streams and for single character transmission of non dictionary words such as the names of people or places
CACM	automatic graders for programming classes
CACM	the use of computers in engineering classroom instruction on april 29 30 the computer committee of the college of engineering university of michigan which acts as a steering committee for the ford foundation project on the use of computers in engineering education held a special conference to discuss certain timely topics pertinent to the ford project this report contains a condensed transcription of the key ideas offered by the conference attendees on selected topics
CACM	report on a conference of university computing center directors
CACM	digital computers in universities iii
CACM	a decision rule for improved efficiency in solving linear programming problems with the simplex algorithm
CACM	rational interpolation by continued fractions algorithm 18
CACM	trdiag algorithm 17
CACM	crout with pivoting algorithm 16
CACM	comments from a fortran user
CACM	rapidly convergent expressions for evaluating e x
CACM	trie memory
CACM	an introductory problem in symbol manipulation for the student
CACM	digital computers in universities  ii
CACM	rootfinder ii algorithm 15
CACM	rootfinder algorithm 2
CACM	rootfinder ii algorithm 15
CACM	abbreviating words systematically corrigendum
CACM	a variant technique for counting ones
CACM	counting ones on the ibm 7090
CACM	a short study of notation efficiency
CACM	neliac a dialect of algol
CACM	programming compatibility in a family of closely related digital computers
CACM	combining algol statement analysis with validity checking
CACM	multiprogram scheduling parts 3 and 4 scheduling algorithm and external constraints
CACM	the multilingual terminology project
CACM	some thoughts on reconciling various character set proposals
CACM	digital computers in universities part i
CACM	complex exponential integral algorithm 13
CACM	atlas a new concept in large computer design
CACM	interval estimation of the time in one state to total time ratio in a doubleexponential process
CACM	the solution of simultaneous ordinary differential equations using a general purpose digital computer
CACM	symbol manipulation by threaded lists corrigendum
CACM	solution of polynomial equation by bairstow hitchcock method a a grau communications acm february 1960 algorithm
CACM	rootfinder algorithm
CACM	evaluation of the legendre polynomial pn x by recursion algorithm
CACM	evaluation of the laguerre polynomial ln x by recursion algorithm
CACM	evaluation of the hermite polynomial hn x by recursion algorithm
CACM	evaluation of the chebyshev polynomial tn x by recursion algorithm
CACM	conversion between floating point representations
CACM	a short method for measuring error in a least squares power series
CACM	multiprogram scheduling parts 1 and 2 introduction and theory in order to exploit fully a fast computer which possesses simultaneous processing abilities it should to a large extent schedule its own workload the scheduling routine must be capable of extremely rapid execution if it is not to prove self defeating the construction of a schedule entails determining which programs are to be run concurrently and which sequentially with respect to each other a concise scheduling algorithm is described which tends to minimize the time for executing the entire pending workload or any subset of it subject to external constraints such as precedence urgency etc the algorithm is applicable to a wide class of machines
CACM	an algorithm defining algol assignment statements addendum
CACM	compiling connectives
CACM	the department of computer mathematics at moscow state university
CACM	the future of automatic digital computers
CACM	bendix g 20 system
CACM	abbreviating words systematically
CACM	a technique for counting ones in a binary computer
CACM	a start at automatic storage assignment
CACM	divisionless computation of square roots through continued squaring
CACM	what is a code
CACM	report on the algorithmic language algol 60
CACM	an imaginary number system
CACM	a high speed multiplication process for digital computers
CACM	euclidian algorithm algorithm 7
CACM	bessel function i asymptotic expansion algorithm 6
CACM	bessel funtion i series expansion algorithm 5
CACM	a control system for logical block diagnosis with data loading this paper describes a section of an integrated diagnostic monitor system which facilitates the checking of sections of instructions or subroutines anywhere in the object program a new method of specifying all diagnostic operations in a format similar to a computer program makes the system convenient to use and relatively simple to understand the paper also describes a number of other novel diagnostic features which can be included in the system
CACM	decoding combinations of the first n integers taken k at a time
CACM	proving theorems by pattern recognition i
CACM	macro instruction extensions of compiler languages macroinstruction compilers constructed from a small set of functions can be made extremely powerful in particular conditional assembly nested definitions and parenthetical notation serve to make a compiler capable of accepting very general extensions to its ground language
CACM	symbol manipulation in xtran
CACM	syntactic and semantic augments to algol
CACM	an introduction to information processing language v
CACM	symbol manipulation by threaded lists
CACM	recursive functions of symbolic expressions and their computation by machine part i
CACM	share standard flow chart symbols
CACM	bisection routine algorithm 4
CACM	numerical inversion of laplace transforms
CACM	an algorithm defining algol assignment statements
CACM	the execute operations a fourth mode of instruction sequencing
CACM	a note on the use of the abacus in number conversion
CACM	soviet computer technology 1959
CACM	computer preparation of a poetry concordance
CACM	marriage with problems
CACM	a new method of computation of square roots without using division
CACM	the basic side of tape labeling
CACM	coding isomorphisms the coding of external symbols into symbols internal to a compute can sometimes be carried out in such a way that relevant informational properties are preserved but in a form much more easily dealt with a case in point is presented
CACM	selfcipher programming
CACM	sequential formula translation the syntax of an algorithmic language such as algol is conveniently described as a sequence of states indicated by an element called cellar transitions are controlled by admissible state symbol pairs which may be represented by a transition matrix this description of syntax furnishes at the same time an extremely simple rule for translating into machine programs statements in the algorithmic language sequential treatment however is not feasible in the case of certain optimizing processes such as recursive address calculation
CACM	a techniquefor handling macro instructions corrigendum
CACM	solution of polynomial equation by bairstow hitchcock method algorithm 3
CACM	rootfinder algorithm 2
CACM	quadi algorithm 1
CACM	a terminology proposal
CACM	a proposal for character code compatibility
CACM	a proposal for a set of publication standards for use by the acm
CACM	a high speed sorting procedure
CACM	abstracts additional nuclear reactor codes
CACM	a sap like assembly program for the ibm 650
CACM	two think pieces
CACM	soviet cybernetics and computer this article records observations on soviet research and technology in cybernetics and computer science made by the author during a visit to the soviet union as a delegate to the ifac congress on automatic control held in moscow in the summer of 1960
CACM	computer production of peek a boo sheets
CACM	simulation and analysis of biochemical systems
CACM	inefficiency of the use of boolean functions for information retrieval systems
CACM	processing magnetic tape files with variable blocks
CACM	machine calculation of moments of a probability distribution a method is presented for the calculation on a machine of the moments of a probability distribution necessitating little more than n additions and n references to memory for each moment instead of the minimum of n multiplication 2n additions and 2n references to memory required by the most straightforward method where n is the number of entries in the probability distribution the method is directly applicable when a tabulated distribution exists as when it has been computed by repeated convolution but in this case it conserves both time and accuracy
CACM	notes on geometric weighted check digit verification this note describes a method for utilizing geometric weight modulus 11 checking digits on a computer which does not have either multiplication or division in addition some attempt has been made to show some limitations of this system
CACM	n dimensional codes for detecting and correcting multiple errors the paper introduces a new family of codes for detecting and correcting multiple errors in a binary coded message the message itself is arranged conceptually into a multidimensional rectangular array the processes of encoding and error detection are based upon parity evaluations along prescribed dimensions of the array effectiveness of the codes is increased by introducing a system check bit which is essentially a parity check on the other parity bits only three dimensional codes are discussed in this paper with parity evaluations along the horizontal the vertical and one main diagonal however the family of codes is not restricted to three dimensions as evidenced by the discussion by minnick and ashenhurst on a similar multidimensional single bit selection plan used for another purpose 6 a four dimensional code correcting three and detecting four errors has been developed the extension to higher dimensional codes with greater correction power is straightforward
CACM	incomplete elliptic integrals algorithm 73
CACM	a set of associate legendre polynomials of the second kind algorithm 62
CACM	least squares fit by orthogonal polynomials algorithm 28
CACM	incomplete elliptic integrals algorithm 73
CACM	what is proprietary in mathematical programming  impressions of a panel discussion a panel discussion on what is proprietary in mathematical programming was sponsored by the special interest committee on mathematical programming of the acm during a hall of discussion on september 7th at the 16th national acm meeting in los angeles this note consists solely of the impressions garnered by the moderator of the panel and does not necessarily represent the position of any of the panelists or other participants in the discussion
CACM	specification languages for mechanical languages and their processors  a bakers dozen
CACM	an engineering application of logic structure tables
CACM	ballistic cam design this paper presents a digital computer program for the rapid calculation of manufacturing data essential to the design of preproduction cams which are utilized in ballistic computers of tank fire control systems the cam profile generated introduces the superelevation angle required by tank main armament for a particular type ammunition
CACM	programming a duplex computer system this paper describes a method of duplex computer programming that has been used with two computers in a military defense system the method combines special programs with a basic data processing program package the duplex operation gives the system greater reliability after achieving the required level of integration both computers do similar processing on the same inputs and continually cross check the intermediate and final results
CACM	on a program for ray chaudhuris algorithm for a minimum cover of an abstract complex
CACM	smalgol 61 prior to and during the 1961 western joint computer conference several people in the joint users groups had expressed interest in defining a smalgol language this is to be an algol language for use with compilers on relatively small size computers a preliminary report resulted at the acm national conference four months later after considering several counter proposals a final version was agreed upon by a subcommittee the recommendations of the subcommittee for a standard subset of algol 60 for use on small computers is presented here
CACM	augmentation algorithm 68
CACM	a set of test matrices algorithm 52
CACM	invert algorithm 42
CACM	composition generator algorithm 72
CACM	permutation algorithm 71
CACM	interpolation by aitken algorithm 70
CACM	tape splitting
CACM	map
CACM	library loading with alternate routine selection
CACM	a generalized polyphase merge algorithm
CACM	low level language subroutines for use within fortran this paper describes some subroutines coded in symbolic languages and for use within fortran coded programs to deal with special arithmetic e g multi precision arithmetic symbol manipulation bit manipulation and expanded character set input output and visual display
CACM	fitting spheres by the method of least squares
CACM	some proposals for improving the efficiency of algol 60
CACM	stochastic evaluation of a static storage allocation
CACM	core allocation based on probability
CACM	techniques for storage allocation algorithms
CACM	a semi automatic storage allocation system at loading time
CACM	a storage allocation scheme for algol 60 a storage allocation scheme for a machine with a 2048 instruction core store and a magnetic drum is described the use of the drum for storing program blocks and or data must be directed by the programmer through auxiliary information in the algol program the administrative routines controlling the storage at run time are described in full a detailed example is given
CACM	experience in automatic storage allocation
CACM	dynamic storage allocation in the atlas computer including an automatic use of a backing store
CACM	dynamic storage allocation for an information retrieval system
CACM	program organization and record keeping for dynamic storage allocation the material presented in this paper is part of the design plan of the core allocation portion of the ascii matic programming system project ascii matic is concerned with the application of computer techniques to the activities of certain headquarters military intelligence operations of the u s army
CACM	problems of storage allocation in a multiprocessor multiprogrammed system
CACM	a general formulation of storage allocation formalization of a general computer storage allocation process is attempted with a given computer m is associated a fictitious computer m essentially identical to m except in respect to possession of unbounded primary storage mappings of the total storage set internal and external of m into the direct address set of m are introduced a program sequence p for m is termed m admissible relative to a specific execution time period if there is a mapping underwhich p and its effective data referents are all located in the direct address set of m storage allocation is considered as a process of establishing for an arbitrary m program a sequence of mappings a decoupling of the program into m admissible subprograms and a linking set of interludes an existence proof in terms of a completely interpretive m program as indicated some special cases are discussed various restrictions on generality of m programs are considered under which more practical realization of allocation processes becomes tractable
CACM	the case for dynamic storage allocation
CACM	a preplanned approach to a storage allocating compiler
CACM	putting a hex on e x recent notes on approximate natural antilogy have not considered indirect formulations for describing e x in this note we produce a particular family of very fast high precision and eminently practical exponential evaluation formulas derived from one such formulation
CACM	optimum tape writing procedures consider a magnetic tape system with a read check after writing where an error occurs in writing a record a programmed error routine may either bypass some or all of the area on tape or try to rewrite the record on the same area this paper evaluates these two procedures on the basis of expected loss of computer time and develops a decision rule for selecting the optimum procedure the rule depends critically on the number of times the tape being written will be used in the future in the case where the optimum procedure is to bypass an area a second decision the size of the area to be bypassed is necessary a formula is developed to determine the optimum area to be bypassed for each procedure
CACM	inversion of a complex matrix
CACM	manipulation of algebraic expressions an algorithm for algebraically manipulating expressions of the form sum cipi i 1 n has been developed in conjunction with the development of programs for systems analysis problems this algorithm enablesus to derive over all system transfer functions from algebraically described block diagrams of any linear continuous multi loop feedback system the machine representation of the derived expression is by virtue of the algorithm in a form which simplifies the task of compiling the algorithm was developed for a particular purpose in connection with system analysis studies however its application as a mathematical device extends far beyond the confines of the original problem
CACM	solution of tridiagonal matrices
CACM	an iterative method for inversion of power series
CACM	the generalized important event technique
CACM	a syntactical chart of algol 60
CACM	critical path scheduling algorithm 40
CACM	chain tracing algorithm 69
CACM	use of mobol in preparingretrieval programs
CACM	an information retrieval language for legal studies
CACM	the applied mathematics laboratory of the david w taylor model basin
CACM	an imaginary number system
CACM	rational approximations for the error function and for similar functions
CACM	a note on multiple precision arithmetic
CACM	a note on fitting great circles by least squares
CACM	a 48 bit pseudo random number generator a new 48 bit pseudo random number generator suitable for several computers was tested statistically for randomness to determine its adequacy for use in monte carlo programs frequency tests distributions of certain low order moments runs up and down and runs above and below the mean were applied to one half million generated numbers lying within the interval 0 1 and to three sets of integers obtained from specified bits within the generated numbers these tests substantiated the randomness of all numbers except for the set of integers coming from the least significant bits
CACM	a generalized polyphase merge algorithm
CACM	cobol a sample problem a simplified merchandise control problem has been chosen for presenting cobol to users and potential users of computing systems a mythical department store e language bros inc is programming in the cobol language one of the many runs on its computer
CACM	a set of test matrices algorithm 52
CACM	augmentation algorithm 68
CACM	some basic terminology connected with mechanical languages and their processors the suggestions in this paper are part of the terminology used in work for the university of pennsylvanias office of computer research and education the work is jointly supported by the national science foundation and the air force office of scientific research
CACM	nth roots of a complex number algorithm 53
CACM	cram algorithm 67
CACM	invrs algorithm 66
CACM	find algorithm 65
CACM	quicksort algorithm 64
CACM	partition algorithm 63
CACM	a set of associate legendre polynomials of the second kind algorithm 62
CACM	procedures for range arithmetic algorithm 61
CACM	a further note on approximating e x
CACM	an iterative method for inversion of power series
CACM	a divisionless method of integer conversion
CACM	solution of tridiagonal matrices
CACM	an algorithm for equivalence declarations
CACM	on the approximation of curves by line segments using dynamic programming
CACM	combat vehicle firing stability active suspension
CACM	on a class of iteration formulas and some historical notes the class of iteration formulas obtainable by rational approximations of eulers formula is derived with the corresponding error estimates some historical notes on iterative procedures are followed by a derivation of eulers formula with the associated error estimate in a new notation which simplifies the error estimate and suggests generalizations the final section considers the pade approximants to the euler polynomial and shows how a number of known formulas may be derived from this unified approach there is a short discussion of the best formula
CACM	logic structure tables logic tables are an excellent way of developing and expressing the logic required in procedures operations systems and circuits a set of rules for writing and using logic tables is explained by means of some simple examples then the logic structure of a vending machine is given in which two logic tables are used logic tables are two dimensional in nature enabling us to fully express and consider both the sequential and parallel aspects of logic they can be compiled directly into a computer program and so eliminate the need for flow charting and hand coding
CACM	algol 60 confidential the algol 60 report when first encountered seems to describe a very complex language which will be difficult to learn the metalinguistic formulae admirably serve the purpose of precisely specifying a language but they are certainly not very readable for a beginner however experience has shown that once the report is explained it is in fact easy to learn algol and to write algorithms in it the language is so general and powerful it can handle an enormous class of problems it is not hard to learn those parts of algol present in other compiler languages how to write assignment and go to and for statements etc indeed a lot of the unnecessary restrictions imposed by other compiling languages have finally been lifted but algol also allows many unobvious things to be written as we will see later and herein lies a problem algol seems to have become too general so many restrictions have been lifted that a lot of technical details crop up which are hard to learn and to use correctly in this paper some of the more obscure features of the language are considered and their usefulness is discussed remarks are based on the authors interpretations of the algol 60 report
CACM	operational compatibility of systems conventions the general standards committee of the share organization has devoted considerable effort to the problem of operating a computer efficiently in view of the growing number of programming systems available each of these programming systems has been coded to utilize a fixed set of hardware components without recognizing the fact that others may be occupying a storage medium required by the first these incompatibilities are currently resolved by manually setting up the computer for each system as required the following set of conventions is being considered to minimize computer set up time they are of sufficiently broad interest that we feel other computer users should be aware of them  george f ryckman chairman
CACM	the state of digital computer technology in europe
CACM	romberg integration algorithm 60
CACM	numerical solution of the polynomial equation algorithm 30
CACM	mathsort algorithm 23
CACM	zeros of a real polynomial by resultant procedure algorithm 59
CACM	matrix inversion algorithm 58
CACM	automatic abstracting and indexing survey and recommendations in preparation for the widespread use of automatic scanners which will read documents and transmit their contents to other machines for analysis this report presents a new concept in automatic analysis the relative frequency approach to measuring the significance of words word groups and sentences the relative frequency approach is discussed in detail as is its application to problems of automatic indexing and automatic abstracting included in the report is a summary of automatic analysis studies published as of the date of writing conclusions are that point toward more sophisticated mathematical and linguistic techniques for the solution of problems of automatic analysis
CACM	a method for evaluating the area of the normal function
CACM	successive approximations and computer storage problems in ordinary differential equations
CACM	an indirect chaining method for addressing on secondary keys methods for entering random access files on the basis of one key are briefly surveyed the widely used chaining method based on a pseudo random key transformation is reviewed in more detail an efficient generalization of the chaining method which permits recovery on additional keys is then presented
CACM	design of an improved transmission data processing code
CACM	division and square root in the quater imaginary number system
CACM	some numerical experiments using newtons method for nonlinear parabolic and ellipticboundary value problems using a generalization of newtons method a nonlinear parabolic equation of the form u t  u xx g u and a nonlinear elliptic equation u xx u yy exp u are solved numerically comparison of these results with results obtained using the picard iteration procedure show that in many cases the quisi linearization method offers substantial advantages in both time and accuracy
CACM	a practical technique for the determination of the optimum relaxation factor of the successive over relaxation method
CACM	further survey of punched card codes
CACM	grout ii algorithm 43
CACM	real exponential integral algorithm 20
CACM	legendre polynomial algorithm 13
CACM	chebyschev polynomial algorithm 10
CACM	solution of polynomial equation by barstow hitchcock algorithm 3
CACM	on frequently occurring errors in algol 60 programs algorithm 25
CACM	ber or bei function algorithm 57
CACM	complete elliptic integral of the second kind algorithm 56
CACM	complete elliptic integral of the first kind algorithm 55
CACM	gamma function for range 1 to 2 algorithm 54
CACM	nth roots of a complex number algorithm 53
CACM	a set of test matrices
CACM	adjust inverse of a matrix when an element is perturbed algorithm 51
CACM	inverse of a finite segment of the hilbert matrix algorithm 50
CACM	spherical neumant function algorithm 49
CACM	logarithm of a complex number algorithm 48
CACM	associated legendre functions of the first kind for real or imaginary arguments algorithm 47
CACM	exponential of a complex number algorithm 46
CACM	interest algorithm 45
CACM	bessel functions computed recursively algorithm 44
CACM	crout with pivoting ii algorithm 43
CACM	invert algorithm 42
CACM	evaluation of determinant algorithm 41
CACM	programmed error correction on a decimal computer
CACM	table look at techniques
CACM	on approximating transcendental numbers by continued fractions
CACM	on the compilation of subscripted variables
CACM	bessel functions of integral order and complex argument
CACM	eigenvalues of a symmetric 3 x 3 matrix
CACM	topological ordering of a list of randomly numbered elements of a network a network of directed line segments free of circular elements is assumed the lines are identified by their terminal nodes and the nodes are assumed to be numbered by a non topological system given a list of these lines in numeric order a simple technique can be used to create at high speed a list in topological order
CACM	real zeros of an arbitrary function algorithm 25
CACM	crout with pivoting algorithm 16
CACM	bisection routine algorithm 4
CACM	remarks on algorithms 2 and 3 algorithm 15 and algorithms 25 and 26
CACM	critical path scheduling algorithm 40
CACM	correlation coefficients with matrix multiplication algorithm 39
CACM	telescope2 algorithm 38
CACM	telescope1 algorithm 37
CACM	tchebycheff algorithm 36
CACM	sieve algorithm 35
CACM	a generalized technique for symbol manipulation and numerical calculation
CACM	bitwise operations
CACM	comparison of iterative methods for the calculation of nth roots three iterative methods for calculation of nth roots including one proposed by the author are compared in two ways 1 theoretical convergence estimates are given 2 a new macrocompiler which estimates machine running time is used to compare the running time of the three methods for a variety of input data
CACM	an alternate form of the uncol diagram
CACM	statistical programs at the university of north carolina
CACM	on finding minimum routes in a network with turn penalties
CACM	gamma function algorithm 34
CACM	factorial algorithm 33
CACM	multint algorithm 32
CACM	gamma function algorithm 31
CACM	solution of polynomial equations by bairstow hitchcock method algorithm 3
CACM	real exponential integral algorithm 20
CACM	complex exponential integral algorithm 13
CACM	the bks system for the philco 2000
CACM	comment on a paper on parallel processing
CACM	two subroutines for symbol manipulation with an algebraic compiler
CACM	multiple programming data processing
CACM	multiple precision division
CACM	automation of program debugging automatic debugging can substantially reduce lead time between the coding and the effective use of a complex program it also enforces analysis of debugging criteria resulting in verifiably accurate programs the programmer specifies the program to be debugged memory areas set of input data maximum repetition of loops and checkpoint information for each set of data the executive debugging program the runs the program to be debugged performing checking functions and creating a trace record of its own later analysis and location of errors applications are quite flexible and the system can be used alone or in conjunction with other debugging techniques
CACM	a card format for reference files in information processing this paper proposes a card format suitable for a variety of reference files in information processing an 80 column ibm card is divided into two fields reference material field columns 1 67 and identification field columns 68 80 the format for the reference material is flexible while the format for the identification is rigid the reference material includes basically an index title source class summary and cross reference for each entry the identification includes basically codes for a matrix of descriptors an entry number and the kind major interest and source of the reference the identification also provides a choice to identify material for personal as well as general files since this card format is sufficient to identify the material normally associated with reference files for books articles programming terms hardware terms equipment machine systems abbreviations etc it is suitable as a standard for card reference files in information processing
CACM	the slang system
CACM	compiling techniques for boolean expressions and conditional statements in algol 60
CACM	comments on the implementation of recursive procedures and blocks in algol 60
CACM	allocation of storage for arrays in algol 60
CACM	dynamic declarations
CACM	thunks    a way of compiling procedure statements with some comments on procedure declarations
CACM	a syntax directed compiler for algol 60
CACM	an algorithm for coding efficient arithmetic operations most existing formula translation schemes yield inefficient coding a method is described which reduces the number of store and fetch operations evaluates constant subexpressions during compilation and recognizes many equivalent subexpressions
CACM	the use of threaded lists in constructing a combined algol and machine like assembly processor
CACM	madcap a scientific compiler for a displayed formula textbook language
CACM	the internal organization of the mad translator
CACM	cl 1 an environment for a compiler a flexible large scale programming system to facilitate the solution of information processing problems and to provide intercommunication between programs and or programmers has been developed and realized on the ibm 709 7090 computer the system is based on a master file concept and has provisions for accepting storing and retrieving both descriptions and instances of large and complex data sets as well as algorithms defined on these data sets both data and algorithms may be expressed in a family of command and descriptive languages the concept of distinct data descriptions and the content and use of such descriptions are discussed in some detail
CACM	the clip translator
CACM	use of magnetic tape for data storage in the oracle algol translator
CACM	recursive processes and algol translation
CACM	a basic compiler for arithmetic expressions
CACM	ibm 1440 data processing system features five new units the ibm 1440 data processing system announced recently by the international business machines corporation not only features the 1311 disk storage drive with interchangeable disk packs but four other newly developed units
CACM	the use of digital computers in western germany
CACM	multiple shooting method for two point boundary value problems
CACM	legal implications of computer use this paper points out a variety of ways computer systems used in business and industry can be involved in legal entanglements and suggests that computer specialists have a responsibility to call for assistance in forestalling or minimizing those entanglements during the planning stage techniques are suggested for making legal clearance effective with the least burden on the new technology and for achieving a favorable legal climate for it generally computer specialists also are alerted to potential opportunities to interpret to lawyers the technical aspects of computer systems involved in legal situations
CACM	random algorithm 133
CACM	magic square algorithm 118
CACM	perm algorithm 115
CACM	position of point relative to polygon algorithm 112
CACM	combination algorithm 94
CACM	matrix inversion algorithm 58
CACM	gamma function algorithm 31
CACM	complete elliptic integral algorithm 149
CACM	term of magic square algorithm 148
CACM	psif algorithm 147
CACM	multiple integration algorithm 146
CACM	adaptive nimerical integration by simpsons rule algorithm 145
CACM	treesort2 algorithm 144
CACM	treesort1 algorithm 143
CACM	triangular regression algorithm 142
CACM	fixed world length arrays in variable word length computers
CACM	character manipulation in 1620 fortran ii
CACM	a decision matrix as the basis for a simple data input routine currently a great deal of time and effort is being spent on the development of bigger and better compiler languages multiprogram executive systems etc since the implementation of of new methods and procedures is not instantaneous but rather occurs by an evolutionary process we should be concerned also with the problem of maintaining improving and incorporating new ideas into existing systems it is with this somewhat neglected area that the author is interested a method employing a decision matrix is presented for the handling of a standard systems programming problem that of providing a data input routine
CACM	evaluation of polynomials by computer
CACM	compiling matrix operations
CACM	mechanical pragmatics a time motion study of a miniature mechanical linguistic system
CACM	on line digital computer for measurement of a neurological control system
CACM	record linkage special difficulties are encountered in devising reliable systems for searching and updating any large files of documents that must be identified primarily on the basis of names and other personal particulars the underlying problem is that of making nearly maximum use of items of identifying information that are individually unreliable but that may collectively be of considerable discriminating power rules that can be applied generally to name retrieval systems have been developed in a methodological study of the linkage of vital and health records into family groupings for demographic research purposes these rules are described and the ways in which information utilization for matching may be optimized are discussed
CACM	topological sorting of large networks topological sorting is a procedure required for many problems involving analysis of networks an example of one such problem is pert the present paper presents a very general method for obtaining topological order it permits treatment of larger networks than can be handled on present procedures and achieves this with greater efficiency although the procedure can be adapted to any machine it is discussed in terms of the 7090 a pert network of 30 000 activities can be ordered in less than one hour of machine time the method was developed as a byproduct of procedures needed by westinghouse baltimore it has not been programmed and at present there are no plans to implement it in regard to the techniques described westinghouses present and anticipated needs are completely served by the lockheed program which is in current use
CACM	crout with equilibration and iteration algorithm 135
CACM	complex number to a real power algorithm 106
CACM	evaluation of jacobi symbol algorithm 99
CACM	combination algorithm 94
CACM	simpsons integration algorithm 84
CACM	certification of the calculation of easter
CACM	path matrix algorithm 141
CACM	matrix inversion algorithm 140
CACM	solution of the diophantine equation algorithm 139
CACM	nesting of for statement ii algorithm 138
CACM	nesting of for statement i algorithm 137
CACM	enlargement of a group algorithm 136
CACM	crout with equilibration and iteration algorithm 135
CACM	exponentiation of series algorithm 134
CACM	random algorithm 133
CACM	quantum mechanical integrals over all slater type integrals
CACM	coefficient determination algorithm 131
CACM	permute algorithm 130
CACM	minifun algorithm 129
CACM	coding of medical case history data for computer analysis
CACM	computer pattern recognition techniques electrocardiographic diagnosis the use of programmed digital computers as general pattern classification and recognition devices is one phase of the current lively interest in artificial intelligence it is important to choose a class of signals which is at present undergoing a good deal of visual inspection by trained people for the purpose of pattern recognition in this way comparisons between machine and human performance may be obtained a practical result also serves as additional motivation clinical electrocardiograms make up such a class of signals the approach to the problem presented here centers upon the use of multiple adaptive matched filters that classify normalized signals the present report fives some of the background for the application of this method
CACM	on ambiguity in phrase structure languages
CACM	syntactic analysis by digital computer this paper provides an account of the shadow language that is used to describe syntax and of a corresponding subroutine that enables a computer to perform syntactic analysis the input to this subroutine consists of a string to be analyzed and a description of the syntax that is to be used the syntax is expressed in the shadow language the output consists of a trace table that expresses the results of the syntactic analysis in a tabular form several versions of the subroutine and some associated programs have been in use now for over three years the present account of the language and the subroutine contains a summary of material that has been described previously in unpublished reports and also some additional discussion of the work in relation to the more general questions of problem oriented languages and string transformations
CACM	perm algorithm 115
CACM	general order arithmetic algorithm 93
CACM	permutation generator algorithm 87
CACM	incomplete elliptic integrals algorithm 73
CACM	critical path scheduling algorithm 40
CACM	summation of fourier series algorithm 128
CACM	ortho algorithm 127
CACM	gauss method algorithm 126
CACM	weightcoeff algorithm 125
CACM	input data organization in fortran
CACM	a test matrix for inversion procedures
CACM	further remarks on sampling a tape file ii
CACM	further remarks on sampling a tape file i
CACM	implementing a stack
CACM	a dispersion pass algorithm for the polyphase merge this paper presents a new manner of dispersing strings for a polyphase merge if the number of strings dispersed is between two levels acceptable by polyphase merge a more economical technique of reaching the next level for polyphase merge is shown and proved
CACM	quick calculation of jacobian elliptic functions corrigendum
CACM	a one day look at computing
CACM	tall a list processor for the philco 200 computer
CACM	on the nonexistence of a phrase structure grammar for algol 60 algol 60 is defined partly by formal mechanisms of phrase structure grammar partly by informally stated restrictions it is shown that no formal mechanisms of the type used are sufficient to define algol 60
CACM	hankel function algorithm 124
CACM	real error function erf x algorithm 123
CACM	tridiagonal matrix algorithm 122
CACM	normdev algorithm 121
CACM	a heuristic for page turning in a multiprogrammed computer
CACM	current status of ipl v for the philco 2000 computer june 1962
CACM	programmed methods for printer graphical output
CACM	use of multiprogramming in the design of a low cost digital computer
CACM	analysis of a file addressing method this paper presents a new file addressing method based on the calculation of an address from the identification of a record for large recirculating type files it seems to be more advantageous than customary ones the probability distribution of the displacement of records from their calculated address which is one less than the number of probes required to address a record is computed on the basis of a markov chain model for the reader not interested in the mathematics the introduction and the summary should be sufficient
CACM	the property classification method of file design and processing
CACM	a finite sequentially compact process for the adjoints of matrices over arbitrary integral domains
CACM	a procedure for inverting large symmetric matrices in the least squares method for simultaneous adjustment of several parameters the coefficients of the normal equations are the elements of a symmetric positive definite matrix in order to solve the normal equations and evaluate the precision measures of the resulting parameters inversion of this matrix of coefficients is required many available procedures for matrix inversion do not take advantage of the symmetry thus when programmed for a high speed computer all n 2 elements must be stored and manipulated whereas only n 1 2 of them are independent in order to allow a computer of given memory capacity to handle a larger matrix the following procedure for inverting a symmetric matrix has been devised
CACM	a set of matrices for testing computer programs
CACM	further remarks on line segment curve fitting using dynamic programming in a recent paper bellman showed how dynamic programming could be used to determine the solution to a problem previously considered by stone the problem comprises the determination given n of the n points of subdivision of a given interval a b and the corresponding line segments that give the best least squares fit to a function g x in the interval bellman confined himself primarily to the analytical derivation suggesting briefly however how the solution of the equation derived for each particular point of subdivision u i could be reduced to a discrete search in this paper the computational procedure is considered more fully and the similarities to some of stones equations are indicated it is further shown that an equation for u i involving no minimization may be found in addition it is shown how bellmans method may be applied to the curve fitting problem when the additional constraints are added that the ends of the line segments must be on the curve
CACM	magic square algorithm 117 118
CACM	permutation generator algorithm 87
CACM	permute algorithm 86
CACM	jacobi algorithm 85
CACM	simpsons integration algorithm 84
CACM	rational roots of polynomials with integer coefficients algorithm 78
CACM	factors algorithm 75
CACM	composition generator algorithm 72
CACM	permutation algorithm 71
CACM	partition quicksort find algorithm 63 64 65
CACM	matrix inversion algorithm 58
CACM	matrix inversion algorithm 58
CACM	ber or bei function algorithm 57
CACM	a set of test matrices algorithm 52
CACM	telescope 1 algorithm 37
CACM	sieve algorithm 35
CACM	binomial coefficients algorithm 19
CACM	rational interpolation by continued fractions algorithm 18
CACM	matrix inversion ii algorithm 120
CACM	evaluation of pert network algorithm 119
CACM	magic square odd order algorithm 118
CACM	magic square even order algorithm 117
CACM	complex division algorithm 116
CACM	perm algorithm 115
CACM	generation of partitions with constraints algorithm 114
CACM	treesort algorithm 113
CACM	position of point relative to polygon algorithm 112
CACM	a computer technique for handling analysis of variance
CACM	character manipulation in fortran
CACM	the description list of concepts a concept is defined as a class of objects whose members can be distinguished by processing its properties property is defined to mean a partition of the set of all objects into disjoint classes the formal definition of a concept is recursive in nature a concept is described by a list structure a one to one correspondence is established between the recursive definition of a concept and its description list structure like the definition the description list structure of a concept is also built up from elementary list structures by a recursive process the list structures obtained this way are compared with the description list structure discussed by the author in a previous publication
CACM	fortran for business data processing
CACM	regression and coded patterns in data editing
CACM	a computer method for radiation treatment planning
CACM	person matching by electronic methods record linkage in the updating of files is accomplished in many establishments through the use of a preassigned number such as payroll number customer number or social security number in vital and health records however a unique number is generally not preassigned to an individual for purposes of reporting services received to the health department in order to determine whether different physician reports refer to the same individual name and other identification must be compared this is a laborious operation which is subject to various errors because of name misspellings changes of name upon marriage and other problems we are interested in the maintenance of a psychiatric case register in maryland where many of the reports from over a hundred psychiatric agencies refer to the same patient these records must be linked in order to provide unduplicated counts of individuals under care and longitudinal records of psychiatric history an earlier paper 1 describes our general procedures for register maintenance by use of a digital computer honeywell 800 here we present in more detail our initial procedures for the person matching process in order to elicit comments and suggestions from persons who have had experience in matching
CACM	on the computation of rational approximations to continuous functions
CACM	digital synthesis of correlated stationary noise in this note we propose a method of generating stationary noise with a prescribed auto covariance function by digital methods the need for such a technique often arises in testing the performance of data processing and engineering systems where inputs corrupted with correlated noise of a known form are required the technique is quite simple and produces strict sense stationary noise which agrees approximately with r t the prescribed auto covariance function acf over an interval  t 0 t 0 the method consists of approximating the spectral density by a periodic process with spectral lines and then synthesizing the periodic noise with random phases and appropriate amplitudes in order to simplify discussion of the statistical properties of the noise generated the technique is first presented in terms of exact harmonic analysis in practice discrete harmonic analysis as presented in the third section is used
CACM	quick calculation of jacobian elliptic functions
CACM	triangular walk pattern for the down hill method of solving a transcendental equation
CACM	nonlinear regression and the solution of simultaneous equations if one has a set of observables z1 zm which are bound in a relation with certain parameters a1 an by an equation s z1 a1 0 one frequently has the problem of determining a set of values of the ai which minimizes the sum of squares of differences between observed and calculated values of a distinguished observable say zm if the solution of the above equation for zm zm n z1 a1 gives rise to a function n which is nonlinear in the ai then one may rely on a version of gaussian regression 1 2 for an iteration scheme that converges to a minimizing set of values it is shown here that this same minimization technique may be used for the solution of simultaneous not necessarily linear equations
CACM	a machine program for theorem proving the program of a proof procedure is discussed in connection with trial runs and possible improvements
CACM	quantum mechanical integrals of slater type orbitals algorithm 110
CACM	definite exponential integrals b algorithm 109
CACM	definite exponential integrals a algorithm 108
CACM	simpsons integration algorithm 84
CACM	factors algorithm 75
CACM	interpolation by aitken algorithm 70
CACM	ber or bei function algorithm 57
CACM	adjust inverse of a matrix when an element is perturbed algorithm 51
CACM	logarithm of a complex number algorithm 48
CACM	gamma function algorithm 34
CACM	molecular orbital calculation of molecular interactions
CACM	quantum mechanical integrals of slater type orbitals
CACM	definite exponential integrals b algorithm 109
CACM	definite exponential integrals a algorithm 108
CACM	gausss method algorithm 107
CACM	complex number to a real power algorithm 106
CACM	newton maehly algorithm 105
CACM	reduction to jacobi algorithm 104
CACM	on translation of boolean expressions
CACM	simulation of computer timing device
CACM	a modified inversion procedure for product form of the inverse linear programming codes this paper describes a new algorithm for the selection of the pivot row in matrix inversion when using the product form of the inverse this algorithm has been developed for linear programming codes however it would be valuable for the inversion of any non dense matrix the procedures described in this paper have been thoroughly tested and have been in operation on the esso research and engineering ibm 7090 computer for nine months substantial computer cost savings have been realized because of this procedure
CACM	solution of eigenvalue problems with approximately known eigenvectors
CACM	communication between independently translated blocks
CACM	analytic differentiation by computer
CACM	avint algorithm 77
CACM	sorting procedures algorithm 76
CACM	cram algorithm 67
CACM	invrs algorithm 66
CACM	matrix inversion algorithm 58
CACM	logarithm of a complex number algorithm 48
CACM	exponential of a complex number algorithm 46
CACM	binomial coefficients algorithm 19
CACM	simpsons rule integrator algorithm 103
CACM	permutation in lexicographical order algorithm 102
CACM	add item to chain linked list algorithm 100
CACM	remove item from chain linked list algorithm 101
CACM	evaluation of jacobi symbol algorithm 99
CACM	evaluation of definite complex line integrals algorithm 98
CACM	shortest path algorithm 97
CACM	ancestor algorithm 96
CACM	generation of partitions in part count form algorithm 95
CACM	combination algorithm 94
CACM	general order arithmetic algorithm 93
CACM	a note on sampling a tape file
CACM	one lost bit
CACM	a redundancy check for algol programs
CACM	report on the algorithmic language fortran ii
CACM	initial experience with an operating multiprogramming system the lewis research center has been using various forms and degrees of program simultaneity in the operation of its modified sperry rand univac scientific model 1103 computer during the last five years this simultaneity has evolved from an initial achievement of self searching input and output to the automatic time sharing of independently coded problems several important machine and program system modifications were necessary to accomplish this evolution several additional modifications although not required were added to facilitate ease of coding and operation all modifications had to proceed at a relatively temperate pace to insure that the basic data reduction work load of the computing center was completed on schedule some educationally valuable mistakes were made and their suggested cures often pointed the way to useful future improvements or emphasized some of the basic principles of a multiprogramming system the material that follows is a description of the evolution of the programming and hardware system which has developed into the present multiprogramming system at lewis research center
CACM	simultaneous system of equations and matrix inversion routine algorithm 92
CACM	romberg integration algorithm 60
CACM	chebyshev curve fit algorithm 91
CACM	evaluation of the fresnel cosine integral algorithm 90
CACM	evaluation of the fresnel sine integral algorithm 89
CACM	evaluation of asymptotic expression for the fresnel sine and cosine integrals algorithm 88
CACM	cobol batching problems
CACM	an introduction to a machine independent data division
CACM	an advanced input output system for a cobol compiler
CACM	guides to teaching cobol the teaching of cobol can be divided into three main subject areas they are the syntax of cobol the use of such syntax in solving any given problem and programming concepts it is generally accepted that some knowledge of the hardware and computer logic must be possessed by the programmer the teaching problem arises in determining how thoroughly a student must know the hardware and logic for that computer for which he will write cobol programs unfortunately historical data concerning students programming proficiency is almost non existent and at best difficult to measure how then might we approach solving this problem
CACM	floating point arithmetic in cobol in this paper the basic operations of floating point arithmetic are examined and cobol procedures for carrying these out are given along with specification of working storage the paper concludes with an example in which these procedures are used
CACM	modular data processing systems written in cobol
CACM	the cobol librarian   a key to object program efficiency many answers to the question how may a cobol compiler be forced into the generation of an efficient object program the purpose of this article is to present one possible answer the creation and full utilization of a well constructed cobol library
CACM	a report writer for cobol
CACM	syntactical charts of cobol 61
CACM	interim report on bureau of ships cobol evaluation program
CACM	cobol and compatibility
CACM	basic elements of cobol 61
CACM	why cobol
CACM	computer simulation of city traffic in simulating traffic flow on city streets the national bureau of standards has used data processing techniques to tabulate and make motion pictures of vehicle movements in the model each vehicle is assigned a digital identification giving points of entry and exit type of vehicle desired speed and actual speed in proportions simulating field data changes in the model can be made to observe their consequences and to determine the ability of a real street to carry loads expected in the future
CACM	a method for eliminating ambiguity due to signal coincidence in digital design
CACM	the calculation of easter
CACM	permutation algorithm 71
CACM	permutation algorithm 71
CACM	sieve algorithm 35
CACM	permutation generator algorithm 87
CACM	permute algorithm 86
CACM	jacobi algorithm 85
CACM	simpsons integration algorithm 84
CACM	addressing multidimensional arrays a useful method of representing a function of n variables is to consider the function to assume its values at selected points in n dimensional space although this picture is of value to the analyst the elements of an n dimensional array must exist in conventional storage as a linear array or vector the means of performing the transformation of a set of indices locating on array element in n space to the location address of the element in its storage vector is the subject of this paper it is noted that the index address transformation is computationally identical to the conversion of a number from a fixed to a mixed radix number system several ways of implementing the transformation are described
CACM	an information algebra   phase i report language structure group of the codasyl development committee this report represents the results of the first phase of the work of the language structure group the goal of this work is to arrive at a proper structure for a machine independent problem defining language at the systems level of data processing the report is based for the most part on a mathematical model called an information algebra developed primarily by r bosak it is hoped that this report will be read a with avid interest by programming language designers and implementors and all those interested in developing a theoretical approach to data processing b with interest and understanding by professional programmers and systems analysts and c with appreciation by the businessman analyst manager the authors have not attempted an exhaustive discourse in this report rather they have tried to present a philosophy to the professional people who are vitally concerned with providing a working language for the systems analysts use they trust that the ideas in this report will stimulate others to think along similar lines questions and comments will be welcomed and can be addressed to any of the members of the language structure group robert bosak system development corporation richard f clippinger honeywell edp division carey dobbs remington rand univac division roy goldfinger chairman ibm corporation renee b jasper navy management office william keating national cash register george kendrick general electric company jean e sammet ibm corporation
CACM	poseidon any computer that forms part of a control system whether completely automatic or partly human must work at the same speed as the control system it must perform its calculations or data processing fast enough for the results to be available at the required instants in the action of the control system this known as working in real time
CACM	computers  the key to total systems control an industrial viewpoint man man machine processes are characterized in five main types and the markets for each type are shown for 1950 and 1960 and estimated for 1970
CACM	retrieval of misspelled names in an airlines passenger record system this paper discusses the limited problem of recognition and retrieval of a given misspelled name from among a roster of several hundred names such as the reservation inventory for a given flight of a large jet airliner a program has been developed and operated on the telefile a stored program core and drum memory solid state computer which will retrieve passengers records successfully despite significant misspellings either at original entry time or at retrieval time the procedure involves an automatic scoring technique which matches the names in a condensed form only those few names most closely resembling the requested name with their phone numbers annexed are presented for the agents final manual selecton the program has successfully isolated and retrieved names which were subjected to a number of unusual as well as usual misspellings
CACM	ratfact algorithm 78
CACM	romberg integration algorithm 60
CACM	optimal classification of objects algorithm 83
CACM	economising a sequence 2 algorithm 82
CACM	economising a sequence 1 algorithm 81
CACM	reciprocal gamma function of real argument algorithm 80
CACM	a method of representation storage and retrieval of 13 random codes in a 4 digit number or 16 random codes in a 5 digit number
CACM	knotted list structures
CACM	on a floating point number representation for use with algorithmic languages
CACM	on a wired in binary to decimal conversion scheme
CACM	an evaluation of autocode readability of the many requirements of an autocode the pair of requirements easy to read and easy to write are not often compatible this paper argues that readability can be added automatically in the translation process so that the programmer can enjoy the utmost economy of expression while for management a full and valid cobol version is printed to give all the advantages of readability and compatibility
CACM	automatic programming language translation through syntactical analysis
CACM	vectorcardiographic diagnosis with the aid of algol
CACM	simulation and analysis of biochemical systems iii analysis and pattern recognition
CACM	manipulation of trees in information retrieval
CACM	a note on multiplying boolean matrices
CACM	tape splitting in an iterative program
CACM	a neliac generated 7090 1401 compiler neliac systems for several different machines have been generated using the original neliac system developed at the naval electronics laboratory san diego in 1958 a basic bootstrap process was used to generate all but the first i e the systems were described in the neliac language and generated by an existing neliac compiler this experience has shown there is no inherent difficulty in building compilers with compilers indeed it pointed out many advantages in using a pol for constructing programming systems this report presents the results of a project completed in may 1961 in which the neliac system was used to generate a compiler for the ibm 1401 the 1401 compiler which runs on the 7090 and produces 1401 programs was described in the neliac language and generated with 7090 neliac system the reduction in programming time and the improvement in documentation of the system were very significant
CACM	surge a recoding of the cobol merchandise control algorithm
CACM	difference expression coefficients algorithm 79
CACM	rational roots of polynomials with integer coefficients algorithm 78
CACM	interpolation differentiation and integration algorithm 77
CACM	an introduction to algol
CACM	simulation and analysis of biochemcial systems ii solution of differential equations
CACM	a string language for symbol manipulation based on algol 60 an artificial computer programming language is proposed for describing the manipulation of strings of characters and symbols the concept of strings introduced in the algol 60 report is extended by adding 1 the declaration of strings substrings and string arrays with explicit lengths 2 the ability to concatenate and shift strings and 3 the ranking of symbols for comparing stings in boolean relations a primer or informal description of the language is followed by examples a description of experiments with the language on an ibm 704 computer and a formal description which taken with the algol 60 report defines the proposed string language
CACM	invrs algorithm 66
CACM	inverse of a finite segment of the hilbert matrix algorithm 50
CACM	numerical solution of the polynomial equation algorithm 30
CACM	sorting procedures algorithm 76
CACM	factors algorithm 75
CACM	curve fitting with constraints algorithm 74
CACM	a survey of languages and systems for information retrieval
CACM	use of semantic structure in information systems
CACM	translation of retrieval requests couched in a semiformal english like language
CACM	language problems posed by heavily structured data
CACM	comit as an ir language many of the features that make comit a good all around symbol manipulation language also render it well suited to various types of information retrieval programs presented here is a general discussion of this unique and different programming language and an examination of some of its applications
CACM	an information system with the ability to extract intelligence from data
CACM	information structures for processing and retrieving
CACM	discussion the pros and cons of a special ir language
CACM	reversion of series algorithm 193
CACM	more test matrices for determinants and inverses pracnique
CACM	indexing and the lambda notation some methods of indexing sequentially stored elements of sparse multi dimensional arrays are described in the scheme a notation
CACM	shuttle sort algorithm 175
CACM	determinant algorithm 159
CACM	assignment algorithm 27
CACM	gauss seidel algorithm 220
CACM	topological ordering for pert networks algorithm 219
CACM	kutta merson algorithm 218
CACM	minimum excess cost curve algorithm 217
CACM	a specification of jovial
CACM	some legal implications of the use of computers in the banking business the introduction of computers in to the banking business has a wide variety of legal implications that merit careful attention at this very early stage the industry is highly regulated by government and hence is subject to many statutes and regulations it also is affected by important common law rules established by courts the legal ramifications involve not only the mechanization itself but also the very significant economically attractive phenomenon of off premises processing it is essential to identify and provide for many legal aspects right now before systems and practices crystallize in order to avoid the later impact of unanticipated physical complications and expense the legal aspects of computerization in the banking business are especially diverse in some states there might be the basic question whether banks are authorized by law to invest in the new facilities either directly or through cooperatives more challenging are questions relating to off premises processors particularly with respect to the obligation not to disclose information concerning a banks customers the adequacy of fidelity bond coverage the extent of liability for improper refusal to pay a check and susceptibility to regulation by government agencies also pertinent is the propriety of data processing by banks for nonbank entities and particularly of the rendering of that service without charge for bank depositors
CACM	telefile a case study of an on line savings bank application the development of an on line computer system for a savings bank institution is traced from the early conceptual needs of the bank to the consummation of design by the teleregister corporation both bank and equipment criteria are specified which led to the development of the telefile system of the teleregister corporation operation of the on line and off line programs are described and statistics are cited for reliability and performance of the system benefits to the bank are discussed from the bankers point of view an indication of future trends in the on line savings bank field is also discussed
CACM	recent developments affecting adp in tax administration
CACM	account classification at automating banks
CACM	application of ibm 1620 edp methods to the calculation of the formation constants of complex irons
CACM	coding clinical laboratory data for automatic storage and retrieval a series of clinical laboratory codes have been developed to accept and store urin analysis blood chemistry and hematology test results for automatic data processing the codes although constructed as part of a computerized hospital simulation have been able to handle the results of every laboratory test that they have encountered the unique feature of these codes is that they can accept conventionally recorded qualitative as well as quantitative test results consequently clinical test results need not be arbitrarily stratified standardized or altered in any way to be coded this paper describes how the codes were developed and presents a listing of the urin analysis codes five criteria used in developing the codes are outlined and the problem of multiple synonymous terminology is discussed a solution to the problem is described flexible computer produced composite laboratory reports are also discussed along with reproduction of such a report the paper concludes that even though many problems remain unsolved the next ten years could witness the emergence of a practical automated information system in the laboratory
CACM	on the computation of a certain type of incompletebeta functions
CACM	length of strings for a merge sort detailed statistics are given on the length of maximal sorted strings which result form the first internal sort phase of a merge sort onto tapes it is shown that the strings produced by an alternating method i e one which produces ascending and descending strings alternately tend to be only three fourths as long as those in a method which produces only ascending strings contrary to statements which have appeared previously in the literature a slight modification of the read backward polyphase merge algorithm is therefore suggested
CACM	optimizing bit time computer simulation a major component of a bit time computer simulation program is the boolean compiler the compiler accepts the boolean functions representing the simulated computers digital circuits and generates corresponding sets of machine instructions which are subsequently executed on the host computer techniques are discussed for increasing the sophistication of the boolean compiler so as to optimize bit time computer simulation the techniques are applicable to any general purpose computer
CACM	recent improvements in madcap madcap is a programming language admitting subscripts superscripts and certain forms of displayed formulas the basic implementation of this language was described in a previous paper madcap a scientific compiler for a displayed formula textbook language comm acm 4 jan 61 31 36 this paper discusses recent improvements in the language in three areas complex display logical control and subprogramming in the area of complex display the most prominent improvements are a notation for integration and for the binomial coefficients in the area of logical control the chief new feature is a notation for variably nested looping the discussion of subprogramming is focused on madcaps notation for and use of procedures
CACM	an error correcting parse algorithm
CACM	flexible abbreviation of words in a computer language
CACM	recursive programming in fortran ii
CACM	a serial technique to determine minimum paths
CACM	interpolation differentiation and integration algorithm 77
CACM	euler summation algorithm 8
CACM	smooth algorithm 216
CACM	shanks algorithm 215
CACM	q bessel functions in t algorithm 214
CACM	report of a visit to discuss common programming languages in czechoslovakia and poland 1963
CACM	usa participation in an international standard glossary on information processing
CACM	a description of the apt language the apt automatically programmed tools language for numerical control programming is described using the metalinguistic notation introduced in the algol 60 report examples of apt usage are included presented also are an historical summary of the development of apt and a statement concerning its present status
CACM	on the inverse of a test matrix
CACM	an extension of fibonaccian search to several variables a technique which uses fibonaccian search concepts has been developed to solve optimization problems involving unimodal functions of several variables the technique has not been proven to be optimal in the sense that the one dimensional fibonaccian search is however it is valuable for certain kinds of calculations
CACM	a comparison of disks and tapes the principal characteristics of current magnetic disks and tape units are summarized and compared some of the characteristics of disk files are illustrated in a sorting example and compared to a tapesort the conclusion is presented that disk files are competitive to tapes in some important applications
CACM	use of the disk file on stretch the paper begins by briefly describing the stretch ibm 7030 computer with special emphasis given to the organization and operation of its input output equipment physical characteristics of the two disk system 4 194 304 72 bit words 8 usec per word transmission rate etc are noted timing limitations due to arm motion and disk rotation are discussed applications of disk usage are discussed separately for problem programs and for systems programs such as compilers and the supervisory program approximately 260 000 words of disk storage are reserved for the storage of systems programs and the subroutine library problem programs however are not currently filed on the disk certain programming techniques are discussed for transmitting words between disk and core storage with minimum delaying and interruption of the arithmetic unit dumps on disk are considered for both recovery from computer malfunction and for mathematical or physical developments during the calculation some comments are made regarding the reliability economics utility and weaknesses or limitations of the disk system several possible future applications are noted which appear to have disk connotations
CACM	an automatic data acquisition and inquiry system using disk files lockheed missiles and space company has installed a large scale automatic data acquisition ada system which ties together the companys manufacturing facilities located in van nuys and sunnyvale california the system includes over 200 remote input stations which collect and transmit company operating data to a central data processing center two rca 301 edp systems are used to record and control the flow of data transmitted to the data processing center a large capacity rca 366 data disc file is used to store information required to provide up to date information in response to inquiries received from remotely located inquiry stations in addition to storage of data on the disk files the system automatically records all incoming and outgoing data on magnetic tape to be used as input to the companys conventional off line business data processing applications
CACM	a numerical method for the determination of moving field isodose curves for treatment planning in radiotherapy
CACM	data dial two way communication with computers from ordinary dial telephones an operating system is described which allows users to call up a remotely located computer from ordinary dial telephones no special hardware or connections are required at the users telephones input to the computer is through the telephone dial output from the computer is in spoken form results of a test with telephones in the boston area are reported
CACM	a contour map program for x ray crystallography a fortran program is described for use with the ibm 7090 system and an x y plotter to produce a contour map a matrix of points evenly spaced in each dimension is contoured scale factors along the axes may be different and the axes need not be perpendicular
CACM	hermite interpolation algorithm 210
CACM	shuttle sort algorithm 175
CACM	assign algorithm 173
CACM	assign algorithm 173
CACM	combinatorial of m things taken one at a time two at a time up to n at a time algorithm 161
CACM	combinatorial of m things taken n at a time algorithm 160
CACM	fourier series approximation algorithm 157
CACM	erf x algorithm 123
CACM	evaluation of the fresnel integrals algorithm 88 89 90
CACM	assignment algorithm 27
CACM	fresnel integrals algorithm 213
CACM	frequency distribution algorithm 212
CACM	hermite interpolation algorithm 211
CACM	lagrangian interpolation algorithm 210
CACM	gauss algorithm 209
CACM	discrete convolution algorithm 208
CACM	stringsort algorithm 207
CACM	partitioning algorithms for finite sets the partitions of a set with n elements are represented by certain n tuples of positive integers algorithm are described which generate without repetitions the n tuples corresponding to 1 all partitions of the given set 2 all partitions of the given set into m or fewer sets 1 m n and 3 all partitions of the given set into exactly m sets 1 m n
CACM	an experiment in automatic verification of programs how effective is a compiler at replacing explicit verification and what is the cost of this technique
CACM	variable width stacks character addressable variable field computers permit ready establishment and manipulation of variable width stacks single machine commands may push variable field items down into such stacks or pop them up the availability of a variety of field delimiters allows the machine to push down or pop up more than one variable width item with one command since these stacking operations can be made the basis of compiler decoding algorithms the proper use of machines of this class for compilation has advantages over machines with fixed length words
CACM	format free input in fortran
CACM	report on proposed american standard flowchart symbols for information processing this paper presents the essential contents of the proposed american standard flowchart symbols for information processing this is the first proposed standard prepared by subcommittee x3 6 on problem description and analysis of the american standards association asa
CACM	alcor group representation of algol symbols
CACM	ecma subset of algol 60
CACM	a profile of the programmer synopsis 549 members of the acm participated in a study concerned primarily with the attitudes of programmers toward their careers and jobs a very high percentage of programmers have apparently entered their careers by accident it has proven a happy choice for most and they expect to remain in the field during the next five years their principal job satisfactions relate to the nature of their work and mostfind their jobs offer high level of professional interest and good working conditions salary and advancement prospects however are not as satisfactory more than half report a positive attitude toward programmers and programming on the part of their organizations turnover among themselves is attributed primarily to poor management salary is seen as the principal motivating factor in turnover among other programmers nature of the work offered and salary are principal determinants in accepting a new job programmers are less mobile than expected programmers tend to see their colleagues in a favorable light on the whole personalities seem to vary with function systems programmers differing from applications programmers four principal problems for programming in the immediate future are listed by participants languages personnel various specific applications and techniques and building programming as a profession
CACM	group participation computer demonstration
CACM	a general program for the analysis of square and rectangular lattice designs this paper describes a general purpose program that will handle those incomplete block designs known as square and rectangular lattices flow diagrams are given so that the method of calculation may be programmed for any digital computer
CACM	on the approximate solution of delta u f u three dimensional dirichlet problems for delta u f u fu 0 are treated numerically by an exceptionally fast exceptionally accurate numerical method programming details numerous examples and mathematical theory are supplied extension of the method in a natural way to n dimensional problems is indicated by means of a 4 dimensional example
CACM	computer drawn flowcharts to meet the need for improved documentation of written computer programs a simple system for effective communication is presented which has shown great promise the programmer describes his program in a simple format and the computer prepares flow charts and other cross referenced listings from this input the description can be kept up to date easily and the final output clearly explains the original program the system has also proved to be a valuable debugging and coding aid
CACM	a generalization of algol
CACM	mirfag a compiler based on standard mathematical notation and plain english a pilot version of the compiler mirfag now in operation is described the chief features of the system which is intended for the solution of scientific problems are the presentation of mathematical formulas entirely in standard textbook notation the use of plain english for organizational instructions automatic error diagnosis indicating the actual location of the error in the uncompiled program and an attempt to minimize that fragmentation of the original problem statement which is a normal feature of programming systems
CACM	symmetric list processor a list processing system in which each list cell contains both a forward and a backward link as well as a datum is described this system is intended for imbeding in higher level languages capable of calling functions and subroutines coded in machine language the presentation is in the form of fortran programs depending on only a limited set of fortran programs depending on only a limited set of primitive machine language subroutines which are also defined finally a set of field particularly character manipulation primitives are given to round out the system
CACM	monte carlo inverse algorithm 166
CACM	newton interpolation with forward divided differences algorithm 169
CACM	newton interpolation with backward divided differences algorithm 168
CACM	calculation of confluent divided differences algorithm 167
CACM	modified hankel functions algorithm 163
CACM	exponentiation of series algorithm 158
CACM	fourier series approximation algorithm 157
CACM	minifun algorithm 129
CACM	interest algorithm 45
CACM	evaluation of determinant algorithm 41
CACM	evaluation of determinant algorithm 41
CACM	arccosin algorithm 206
CACM	ative algorithm 205
CACM	steep2 algorithm 204
CACM	steep1 algorithm 203
CACM	generation of permutations in lexicographical order algorithm 202
CACM	a semi iterative process for evaluating arctangents
CACM	note onstochastic matrices
CACM	pei matrix eigenvectors
CACM	a note on a set of test matrices for inversion
CACM	closing out a print tape
CACM	a procedure for converting logic table conditions into an efficient sequence of test instructions
CACM	ye indiscreet monitor
CACM	an exponential method of numerical integration of ordinary differential equations a formula for numerical integration is prepared which involves an exponential term this formula is compared to two standard integration methods and it is shown that for a large class of differential equations the exponential formula has superior stability properties for large step sizes thus this formula may be used with a large step size to decrease the total computing time for a solution significantly particularly in those engineering problems where high accuracy is not needed
CACM	a computer program for editing the news
CACM	simulation of a traffic network
CACM	skeletal structure of pert and cpa computer programs an introduction to the inner mechanics of pert and cpa computer programs is provided the major components of these programs as well as their purposes and interrelationships are outlined
CACM	continued operation notation for symbol manipulation and array processing a brief account is given of a notational device that is very useful in the formal representation of syntaxes string relationships and string transformation procedures and also of computing procedures that deal with arrays of functions of many variables the device consists of the use of certain continued operation or collective symbols that are analogous to the summation symbol sigma and continued multiplication symbol pi of conventional mathematics
CACM	dialects of fortran
CACM	a note on the dangling else in algol 60 some revisions of algol 60 are proposed which not only eliminate certain ambiguous statements but also add some convenience to the language a discussion of the background of the problem and a sketch of a proof that the ambiguities have been removed is included
CACM	some remarks on the syntax of symbolic programming languages
CACM	a syntax controlled generator of formal language processors
CACM	reduction of a matrix containing polynomial elements algorithm 170
CACM	orthogonal polynomial least squares surface fit algorithm 164
CACM	xy move plotting algorithm 162
CACM	certification of algorithm 161 combinatorial of m things taken one at a time two at a time up to n at a time m l wolfson and h v wright comm acm apr 1963
CACM	certification of algorithm 160 combinatorial of m things taken n at a time m l wolfson and h v wright comm acm apr 1963
CACM	algebra of sets algorithm 156
CACM	combination in any order algorithm 155
CACM	combination in lexicographical order algorithm 154
CACM	gomory algorithm 153
CACM	matrix inversion algorithm 140
CACM	jacobi algorithm 85
CACM	interpolation differentiation and integration algorithm 77
CACM	partition quicksort and find algorithm 62 64 65
CACM	a set of test matrices algorithm 52
CACM	associated legendre functions of the first kind for real or imaginary arguments algorithm 47
CACM	crout ii algorithm 43
CACM	algorithm 42 invert alg 107 gausss method alg 120 inversion ii and gjr
CACM	telescope 2 algorithm 38
CACM	telescope 1 algorithm 37
CACM	shellsort algorithm 201
CACM	normal random algorithm 200
CACM	conversions between calendar date and julian day number algorithm 199
CACM	adaptive integration and multiple integration algorithm 198
CACM	matrix division algorithm 197
CACM	mullers method for finding roots of an arbitrary function algorithm 196
CACM	bandsolve algorithm 195
CACM	zersol algorithm 194
CACM	character manipulation in 7090 fortran
CACM	multiple precision binary to decimal integer conversion using only addition and subtraction
CACM	mapped list structures
CACM	a list type storage technique for alphameric information a method which is economic in terms of space and time is proposed for the storage and manipulation of character strings of arbitrary length in a fixed word length computer the method is illustrated in an application to algol type identifiers in an algol like block structure
CACM	debugging systems at the source language level
CACM	sabrag a time sharing low cost computer the serial sabrac computer designed and built in the scientific department of the israel defense ministry has a 5000 location magnetic drum main store to avoid a need to resort to optimum programming techniques and to increase its overall efficiency the computer has also been given a 224 word ferrite core store from which the program is obeyed transfers between the core and drum stores and to and from the twin paper tape input and output channels are all available autonomously concurrently time shared multiplication and division orders are also autonomous so that the machine may be executing up to three orders simultaneously all functions naturally are interlocked a number of other advanced orders and facilities are also incorporated in particular an execute order permits a temporary jump for up to four orders and a second modifier register permits double modification in general and relative addressing of subroutines in particular thus the overall effective speed of the machine is muchhigher than its basic specification would lead one to expect and its design indicates one way in which the concepts of time sharing may be incorporated in low cost computers
CACM	american standard code for information interchange
CACM	a catalogue entry retrieval system
CACM	design of a separable transition diagram compiler a cobol compiler design is presented which is compact enough to permit rapid one pass compilation of a large subset of cobol on a moderately large computer versions of the same compiler for smaller machines require only two working tapes plus a compiler tape the methods given are largely applicable to the construction of algol compilers
CACM	the linking segment subprogram language and linking loader
CACM	least squares solution with constraints algorithm 177
CACM	syminv2 algorithm 150
CACM	syminv2 algorithm 150
CACM	exponentiation of series algorithms 134
CACM	newton maehly algorithm 105
CACM	remark on certification of matrix inversion procedures
CACM	reversion of series algorithm 193
CACM	confluent hypergeometric algorithm 192
CACM	hypergeometric algorithm 191
CACM	complex power algorithm 190
CACM	smoothing 2 algorithm 189
CACM	smoothing 1 algorithm 188
CACM	differences and derivatives algorithm 187
CACM	complex arithmetic algorithm 186
CACM	normal probability for curve fitting algorithm 185
CACM	erlang probability for curve fitting algorithm 184
CACM	nexcom algorithm 152
CACM	realizing boolean connectives on the ibm 1620
CACM	polynomial evaluation revised
CACM	checking for loops in networks
CACM	further remarks on sampling a tape file iii
CACM	real time programming specifications problems in the implementation of large real time applications are treated and suggested guidelines for both program and file specifications are developed the problems delineated also occur in systems programming
CACM	a syntactic description of bc nelliac
CACM	descriptran automated descriptive geometry descriptive geometry consists of procedures originally designed to solve 3 space geometry problems by graphical constructions and measurement instead of by computation however in addition to this it unifies and simplifies the approach to many such problems when one can call subroutines that compute new coordinates that correspond to those obtainable from the graphical constructions there is the three way advantage of the approach of descriptive geometry the accuracy of computation and the speed of the digital computer descriptran makes it possible to program many problems in 3 space with a few statements it consists of 15 subroutines analogous to the procedures of descriptive geometry
CACM	pip a photo interpretive program for the analysis of spark chamber data an operating computer program that processes photographically recorded data is described the input to the program consists of spark chamber photographs on which tracks of high energy particles are recorded the program automatically scans measures and performs the preliminary interpretation of these photographs in continuous operation a processing rate of 5 000 photographic frames per hour is achieved
CACM	remarks on fortran subroutines for time series analysis
CACM	disk file sorting sorting techniques using an ibm 1401 with a random access storage device are evaluated
CACM	incompressible flow network calculations a general method for the calculation of flows and pressures in fluid flow networks is presented the method is applicable to computer use
CACM	the external language klipa for the ural 2 digital computer
CACM	corc the cornell computing language
CACM	real error function erf algorithm 123
CACM	curve fitting with constraints algorithm 74
CACM	reduction of a symmetric bandmatrix to triple diagonal form
CACM	nonrecursive adaptive integration algorithm 182
CACM	complementary error function large x algorithm 181
CACM	error function large x algorithm 180
CACM	incomplete beta ratio algorithm 179
CACM	direct search algorithm 178
CACM	least squares solution with constraints algorithm 177
CACM	least squares surface fit algorithm 176
CACM	shuttle sort algorithm 175
CACM	a posteriori bounds on a zero of a polynomial algorithm 174
CACM	assign algorithm 173
CACM	1410 fortran edit feature
CACM	another test matrix for determinants and inverses
CACM	self inverse conversion table
CACM	a penny matching program the logic of a penny matching program written for the csx 1 is described
CACM	a note on range transformations for square root and logarithm there was the germ of an idea in two previous papers 1 2 which no one seems to have picked up in almost five years for certain functions it seems desirable to transform the argument to a short range symmetric about 10 1 will give examples of this usage for the square root and logarithm function for both binary and decimal machines
CACM	use of tree structures for processing files in data processing problems files are frequently used which must both be searched and altered binary search techniques are efficient for searching large files but the associated file organization is not readily adapted to the file alterations conversely a chained file allocation permits efficient alteration but cannot be searched efficiently a file organized into a tree like structure is discussed and it is shown that such a file may both be searched and altered with times proportional to slog s n where n is the number of file items and s is a parameter of the tree it is also shown that optimizing the value of s leads to a search time which is only 25 per cent slower than the binary search the tree organization employs two data chains and may be considered to be a compromise between the organizations for the binary search and the chained file the relation of the tree organization to multidimensional indexing and to the trie structure is also discussed
CACM	conversion reconversion and comparison techniques in variable length sorting the logic is described for converting highly variable input records into a format that can be easily and efficiently processed by a sorting program the internal record formats are discussed in relation to 1 their conversion from input formats 2 their reconversion to output formats and 3 comparison techniques between internal formats
CACM	design and characteristics of a variable length record sort using new fixed length record sorting techniques this paper describes the application of several new techniques for sorting fixed length records to the problems of variable length record sorting the techniques have been implemented on a sylvania 9400 computer system with 32 000 fixed length words of memory specifically the techniques sequence variable length records of unrestricted size produce long initial strings of data merge strings of data at the power of t 1 where t is the number of work tapes in a system and do not restrict the volume of input data
CACM	a method of comparing the time requirements of sorting methods
CACM	the cobol sort verb
CACM	some characteristics of sorting in computing systems using random access storage devices the substantial differences in characteristics of random access storage and tape devices dictate that concepts and objectives of computer program design be considered from the viewpoint of the external file medium used this is particularly true in the case of sorting in a tape oriented system the major sorting problem is that of minimizing merge time despite the limited orders of merge possible in contrast sorting in a random access oriented system encourages the selection of the optimum order of merge from many possible orders the latter problem is discussed in this paper along with criteria developed for determining the optimum order of merge according to the various properties of random access storage devices attention is also given to the problem of key sorting versus record sorting and the possibly serious disadvantage of key sorting on a random access system
CACM	organization and structure of dataon disk file memory systems for efficient sorting and other data processing programs an approach to the organization and structure of data on bryant disc file memory systems for sorting and performing other data processing functions is presented the following areas are covered characteristics of bryant disc file systems on the bendix g 20 and rca 301 two proposed chaining structures for data and functions of a disk file executive routine the concepts for sorting and performing file maintenance processing using the proposed structure and executive routine are discussed additionally it is shown that sorting can be accomplished without the use of disk storage work areas
CACM	sorting with large volume random access drum storage an approach to sorting records is described using random access drum memory the sort program described is designed to be a generalized self generating sort applicable to a variety of record statements this description is divided into three parts the first part presents the operating environment the second defines the general solution the third part describes the internal sort merge technique
CACM	sorting nonredundant files techniques used in the fact compiler some typical file structures including some called non redundant are examined and the methods used in fact to sort such files are discussed
CACM	a tape file merge pattern generator a routine is presented which specifies the sequence of merge cycles to effect the merging of sorted tape files the routine is designed to minimize elapsed computer time by varying the power of the merge cycles so as to use all the available tape drives with its characteristic of assigning one drive to a single reel file and two drives to each multiple reel file
CACM	computer planned collates
CACM	a comparison between the polyphase and oscillating sort techniques a comparison between the oscillating and polyphase sort techniques is developed for computer systems having from four to ten tape drives the basis for the comparison is the total reading and writing required for various number of input strings and tape drives for the two techniques
CACM	read backward polyphase sorting read backward polyphase sorting provides more efficient use of the tapes available to a sort than most other sorting techniques backward polyphase produces a continuous merging process from n 1 tapes where n is the total number of tapes being used in the sorting process any of the available presorting techniques may be used in conjunction with the polyphase merge sort provided that the presort has the capability of producing both ascending and descending strings and distributing the strings on the various tapes as required by the polyphase merge
CACM	string distribution for the polyphase sort
CACM	multiphase sorting
CACM	an empirical study of minimal storage sorting
CACM	internal and tape sorting using the replacement selection technique a general technique for sequencing unsorted records is presented the technique is shown to be applicable for the first stage of a generalized sort program the formation of initial strings as well as for sorting records within a memory storage an internal sort it is shown that given n records in memory storage records are sequenced using 1 log2 n tests per record that initial string lengths will average 2n for random input records and that reading writing and processing can be accomplished simultaneously if the computer permits such overlap
CACM	sorting on computers
CACM	least squares fitting of planes to surfaces using dynamic programming dynamic programming has recently been used by stone by bellman and by gluss to determine the closet fit of broken line segments to a curve in an interval under the constraint that the number of segments is fixed in the present paper successive models are developed to extend the method to the fitting of broken plane segments to surfaces z g x y defined over certain types of subareas of the x y  space the first model considers a rectangular area with the constraint that the plane segments are defined over a grid in the x y  space it is then shown how this model may be incorporated into an algorithm that provides successive approximations to optimal fits for any type of closed area finally applications are briefly described
CACM	a suggested method of making fuller use of strings in algol 60
CACM	term of magic square algorithm 148
CACM	term of magic square algorithm 148
CACM	psif algorithm 147
CACM	adaptive numerical integration by simpsons rule algorithm 145
CACM	random algorithm 133
CACM	chebyshev curvefit algorithm 91
CACM	incomplete elliptic integrals algorithm 73
CACM	complete elliptic integral algorithm 149
CACM	complete elliptic integral of the first kind algorithm 55
CACM	reduction of a matrix containing polynomial elements algorithm 170
CACM	newton interpolation with forward divided differences algorithm 169
CACM	newton interpolation with backward divided differences
CACM	calculation of confluent divided differences algorithm 167
CACM	monte carlo algorithm 166
CACM	complete elliptic integrals algorithm 165
CACM	orthogonal polynomial least squares surface fit algorithm 164
CACM	modified hankel function algorithm 163
CACM	xy move plotting algorithm 162
CACM	combinatorial of m things taken one at a time two at a time up to n at a time algorithm 161
CACM	algorithm 160 combinatorial of m things taken n at a time
CACM	official actions and responses to algol as a programming language
CACM	selected definitions a selection of the definitions prepared by the acm standards committees subcommittee on programming terminology is presented for review by the acm membership
CACM	everymans information retrieval system the information retrieval problem whose solution is presented here was posed by a technical library with limited bubget and personnel the solution however is quite general and is applicable to many different types of retrieval problems further the method of solution makes it possible for many groups who have previously dismissed an information retrieval program as expensive and difficult from a programming stand point to reconsider their position for the present solution makes it possible to install an information retrieval program in less than three months and with relatively little equipment
CACM	recol a retrieval command language an interrogation scheme is described for the retrieval and manipulation of data file records the language of the interrogation scheme allows for selecting file records with the are of logical condition statements defining record classes associating file records editing printed output and summarizing the results of the above operations some examples of a typical file application and the more significant features of a particular machine implementation are given
CACM	significance arithmetic on a digital computer the 7090 at nyu has been modified to include a significance mode of operation which is intended to facilitate the identification of significant bits in the results of floating point arithmetic operations the manner in which floating point arithmetic is handled in this mode is discussed several numerical experiments using this mode are described and comparisons are made with the ordinary normalized mode examples include power series evaluation linear equations solution determinant evaluation and matrix inversion
CACM	an iterative factorization technique for polynomials an iterative technique is displayed whereby factors of arbitrary degree can be found for polynomials in one variable convergence is shown to occur always if a certain jacobian does not vanish and if the initial approximation to a factor is near enough to an actual factor the process is simply programmed and preliminary results indicate it to be well adapted to use with digital computers for factors of degree two the technique is similar to that of bairstow the present method being somewhat simpler
CACM	a computational extension of the variate difference method presented here is a computational extension of the variate difference method as developed by g tintner 1
CACM	characteristic values and vectors of defective matrices
CACM	note on the proof of the non existence of a phrase structure grammar for algol 60
CACM	random algorithm 133
CACM	magic square algorithm 117 118
CACM	ancestor algorithm 79
CACM	difference expression coefficients algorithm 79
CACM	determinant algorithm 159
CACM	exponentiation of series algorithm 134
CACM	fourier series approximation algorithm 157
CACM	algebra of sets algorithm 156
CACM	combination in any order algorithm 155
CACM	combination in lexicographical order algorithm 154
CACM	test matrix for inversion
CACM	arithmetizing declarations corrigendum
CACM	selective instruction trap for the 7090
CACM	a variant method of file searching
CACM	addressing an array yi in k dimensions by fortran for analysis of variance
CACM	neliac
CACM	jovial and its documentation
CACM	documentation of ipl v
CACM	fortran
CACM	comit
CACM	cobol
CACM	documentation problems algol 60
CACM	toward better documentation of programming languages
CACM	incomplete elliptic integrals algorithm 73
CACM	multint algorithm 32
CACM	gomory algorithm 153
CACM	nexcom algorithm 152
CACM	location of a vector in a lexicographically ordered listalgorithm 151
CACM	syminv2 algorithm 150
CACM	linear programming applied to ultraviolet absorption spectroscopy
CACM	character manipulation in fortran
CACM	glossary construction
CACM	decimal to binary conversion of short fields
CACM	systematic mistake analysis of digital computer programs
CACM	matrix inversion by gauss jordan inversion ii algorithm 120
CACM	magic squares algorithm 117 118
CACM	gausss method algorithm 107
CACM	calculating primes by means of gps algorithm
CACM	a set of test matrices algorithm 52
CACM	inverse of a finite segment of the hilbert matrix algorithm 50
CACM	invert algorithm 42
CACM	gamma function algorithm 31
CACM	generating discrete random variables in a computer this note is concerned with details of how to instruct a computer to choose one from many things with assigned probabilities the method uses a uniform variable to direct the computer to a memory location if this is done by a sequence of appropriately chosen conditional probabilities efficient use of memory space and quite fast programs will result
CACM	a recursive program for the general n dimensional integral a general program is outlined for n dimensional integration with variable limits the program is of a recursive nature and uses simpsons rule combined with repeated bisection to attain the required accuracy it was developed in the ferranti mercury autocode scheme
CACM	fortran subroutines for time series analysis the authors have recently been concerned in a time series study that constituted a fairly typical piece of applied statistical research involving extensive computations on a moderately large quantity of data wehave found that the many different numerical processes that were required could be built up almost completely from a small number of basic operations and a set of fortran subroutines has been written to perform these the main purpose of this note is to describe these subroutines but since the question of general statistical programs is topical 1 we include some general remarks
CACM	terms frequently combined in problem description
CACM	storage and search properties of a tree organized memory system a memory with list properties 1 may be used to construct numeric alphabetic or alphanumeric trees such trees have information storage and retrieval properties applicable to problems involving large quantities of data or to problems where the quantity word length and distribution of stored information is not known a priori or changes rapidly during the processing the purpose of this paper is to examine the storage and search properties of a tree organized storage system assuming that a memory possessing certain list properties is available of prime interest is the application where a symbol table dictionary or similar file is to be stored and searched
CACM	arithmetizing declarations an application to cobol
CACM	suggestions on algol 60 rome issues   a report by the american standards association subcommittee x3 4 2
CACM	supplement to the algol 60 report
CACM	note on the use of procedures
CACM	integer and signed constants in algol a few remarks are given on the relations between syntax and semantics in the programming languages the aim is to point out that if it is true that the grammar of a context free language should be conceived not only as a strings generating device but also as a method for expressing a meaning then the grammar of algol is open to some criticism
CACM	parallel methods for integrating ordinary differential equations this paper is dedicated to the proposition that in order to take full advantage for real time computations of highly parallel computers as can be expected to be available in the near future much of numerical analysis will have to be recast in a more parallel form by this is meant that serial algorithms ought to be replaced by algorithm which consist of several subtasks which can be computed without knowledge of the results of the other subtasks as an example a method is proposed for parallelizing the numerical integration of an ordinary differential equation which process by all standard methods is entirely serial
CACM	rational chebyshev approximations to the bessel function integrals kis x the second remes algorithm is used to approximate the integrals kis by rational functions the related coefficients for the approximations of ki1 ki2 ki3 are given for different precisions
CACM	another use of fortran ii chaining
CACM	scanning text with a 1401
CACM	a note on the calculation of probabilities in an f distribution
CACM	a class of matrices to test inversion procedures
CACM	a family of test matrices
CACM	method for partial rewriting of magnetic tape
CACM	a case of too much precision
CACM	mark sense and port a punch programming inputs
CACM	curve fitting with format fortran
CACM	limited bit manipulation using fortran ii techniques are developed for manipulating bits using only fortran ii these techniques allow individual bits to be tested certain fields to be shifted and numbers coded in bcd to be converted to binary
CACM	double precision squares root for the cdc 3600 in january of 1960 the late hans j maehly completed a summary of approximations to the elementary functions for the cdc 1604 computer the approximations and techniques suggested by maehly are equally applicable to the second large computer in the cdc line the 3600 unlike the 1604 however the 3600 has built in double precision floating point arithmetic the present work largely inspired by the successes of maehly and his associates concerns the extension of one of maehlys ideas to a double precision subroutine for the 3600
CACM	relative effects of central processor and input output speeds upon throughput on the large computer presented in this paper is a technique for determining the relative effects of the internal speed of the computer and the speed of the input output units upon the overall speed of the system equations are derived which permit the determination of these effects from hardware usage measurements
CACM	mechanization of tedious algebra the e coefficients of theoretical chemistry a table of formulas for certain integrals involving legendre functions has been constructed mechanically by a program which performed algebraic operations the formulas are all rational algebraic expressions in a single variable and were constructed by a recurrence procedure they are of interest in molecular quantum chemistry trivial coding techniques were used to write the relevant programs in fortran the results were photo composed on a photon s 560 system that was controlled by tapes which were punched directly from the computer output so avoiding manual keyboarding transcription errors and keyboarded correction
CACM	greatest common divisor algorithm 237 a1
CACM	evaluation of determinant algorithm 224 f3
CACM	complementary error function algorithm 181 s15
CACM	radical inverse quasi random point sequence algorithm 247 g5
CACM	graycode algorithm 246 z
CACM	treesort 3 algorithm m1
CACM	time sharing in a traffic control program the toronto traffic signal control system consists of a variety of logically distinct computer programs all competing for machine time to satisfy these demands a time sharing program has been written whose purpose is to execute in the order of a predefined priority the various subprograms within the real time system in this paper the more interesting aspects of the time sharing program are outlined
CACM	an executive system implemented as a finite state automaton the 473l command and control system used by the air force permits many operators to access large data files through the use of a computer the man machine interface is satisfied by several communication consoles from which operators may enter queries and view replies a data link permits remote stations to send messages status reports and inventories directly to the computer the information received over the on line data link is used to update the data files which are stored on disk the 473l programming system is divided into an executive control program and five components with different processing priorities these priorities permit the system to be most sensitive to the console inputs and permit the operators at all the consoles to time share the central processor the executive control program provides for the orderly transitions of control among the programming system components the major emphasis of the paper is on the technique of using the definition of a finite state automaton for organizing the executive control program
CACM	estimation of heart parameters using skin potential measurements a fundamental problem of vector cardiography is the estimation of the state of the heart on the basis of skin potential measurements a mathematical model relating ventricular dipoles to surface potentials is sketched then it is shown that the inverse problem that of determining electrical heart parameters on the basis of skin potential measurements may be viewed as a nonlinear multipoint boundary value problem a feasible solution employing quasilinearization and high speed digital computers is given
CACM	a technique for reading gapless tapes makes electrocardiograph analysis feasible on the ibm 7090 to study arrhythmias and higher frequency components of the electrocardiogram long series of patient heart cycles must be examined before valid comparison of different heart beats can be made a technique is presented for the automatic analysis of long series heart cycles via a digital computer
CACM	the new program of work for the international standard vocabulary in computers and information processing
CACM	fresnel integrals algorithm 213 s20
CACM	conversions between calendar date and julian day number algorithm 199 z
CACM	fresnel integrals algorithm 244 s20
CACM	logarithm of a complex number algorithm 243 b3
CACM	multiple precision arithmetic and the exact calculation of the 3 j 6 j and 9 j symbols described in this paper is a system of general purpose multiple precision fixed point routines and their use in subroutines which calculate exactly the quantum mechanical 3 j 6 j and 9 j symbols of large arguments
CACM	rounding problems in commercial data processing a common requirement in commercial data processing is that the sum of a set of numbers rounded in a generally understood manner be equal to the sum of the numbers rounded individually four rounding procedures are described to accomplish this the particular procedure that is appropriate depends upon whether the numbers being accumulated can vary in sign whether their sum can vary in sign and whether the last number being summed can be recognized as such prior to its rounding
CACM	an inductive approach to language translation the possibility of natural language translation by means of fixed operations on example translations is considered the conception of sentence translation which motivates the work is informally presented and the measurement of physical similarity in pairs of strings is discussed a notion which plays a central role in the proposed type of translator experimental evidence is presented in support of the premise upon which this conception is based
CACM	take up reels for one inch perforated tape for information interchange proposed american standard
CACM	report on input output procedures for algol 60 ifip
CACM	report on subset algol 60 ifip
CACM	proposed amendment to proposed american standard on specification for general purpose paper cards for information processing
CACM	fortran vs basic fortran a programming language for information processing on automatic data processing systems
CACM	history and summary of fortran standardization development for the asa
CACM	a method of syntax specification
CACM	constraint type statements in programming languages a proposal is made for including in a programming language statements which imply relations between variables but which are not explicit assignment statements the compiler sets up a newtonian iteration making use for the purpose of a routine for formal differentiation
CACM	gamma function with controller accuracy algorithm 225 s14
CACM	gamma function algorithm 221 s14
CACM	kutta merson algorithm 218 d2
CACM	stringsort algorithm 207 m1
CACM	steep1 algorithm 203 e4
CACM	permutations of a set with repetitions algorithm 242 g6
CACM	patent protection of computer programs
CACM	computer programs are patentable
CACM	joint inventorship of computers
CACM	computer patent disclosures
CACM	copyright aspects of computer usage this paper is concerned with the question of what constitutes infringement of a copyright on a book or other nondramatic literary work when the work is fed into a computer and is indexed analyzed partially reprinted or otherwise utilized by the computer to produce eye readable output the question of copyrightability of programs and infringement of copyrights on programs is also discussed the paper is directed primarily to a discussion of the present law some aspects of the proposed new copyright law are also included general recommendations are made with respect to the proposed revision of the copyright law
CACM	a rapid method for digital filtering since much of the computer time spent in time series analysis is used for multiplications a minimum multiplication method was devised for digital filtering with the expectation that it would be useful in the on line real time analysis of biological data the filters are constructed from a succession of readily analyzable components in a manner that facilitates cascading the repertoire of frequency response curves includes relatively good low pass and band pass designs programs are available for implementing both the synthesis of these filters and their application on computers whose assemblers allow the definition of recursive macros
CACM	a computer analysis method for thermal diffusion in biochemical systems in the thermal detection of rapid biochemical reactions it is necessary to correct the temperature data for transient heat conduction losses in a cylindrical calorimeter to handle the complexities arising from varying thermal relaxation times of concentric insulating layers a computer program was developed which gives the temperature distribution of the system as a function of radius and time this distribution is corrected at each step by a subroutine which calculates the instantaneous chemical state of there action as well as the heat produced by this reaction the program is based on a direct statement of fouriers law of heat conduction and the chemical rate equation to provide a bookkeeping law to follow the reactants and the flow of heat packets in such a way that the computer continually stores the heat distribution a computer analysis method is here regarded as one in which the physical laws of a process are used explicitly in the program usually this results in by passing much of the mathematical procedures conventionally used the program was tested against some known exact solutions of the heat equation and gave identical results and compared well with experimental data of a known biochemical reaction the construction of computer programs based on the direct statement of the physical laws is a principle of general applicability which has been applied to several other physical phenomena
CACM	arctangent algorithm b1
CACM	coordinates on an ellipsoid algorithm 240 z
CACM	a storage allocation and reference structure a method is proposed and discussed which allows a subscripted variable capability in the fortran sense to be added to autocoder type assembly systems
CACM	extension of existing compilers by sophisticated use of macros a description is presented of an application in which macros and string concatenation were employed to add a new facility to belfap
CACM	scheduling meetings with a computer computer scheduling of papers as it was developed for the 1960 meeting of the federation of american societies for experimental biology faseb is described the faseb meeting is the largest scientific meeting held in the united states each year the technique developed for faseb can be applied to schedule any meeting with parallel sessions
CACM	solution of combinatorial problems using generating functions on a variable field computer the utility of generating functions in solving combinatorial problems is discussed particular implementation results are presented and evaluated
CACM	a multiuser computation facility for education and research present day computing facilities are limited in their value for scientific research by inability to interact strongly with users the full power of a research computing instrument should be available at many terminals that give each user the ability to generate correct and operate any procedure he wishes either simple or complex implementation is described for a small scale multiuser computer system that permits several users to work independently with the machine and to obtain satisfactory response using typewriter communication
CACM	logarithm of a complex number algorithm 48 b3
CACM	formal parsing systems automatic syntactic analysis has recently become important for both natural language data processing and syntax directed compilers a formal parsing system g v u t r consists of two finite disjoint vocabularies v and t a many many map u from v onto t and a recursive set r of strings in t called syntactic sentence classes every program for automatic syntactic analysis determines a formal parsing system a directed production analyzer i t x p is a nondeterministic pushdown store machine with internal vocabulary i input vocabulary t and all productions of p in the form z a   ay1 ym where z yi are elements of the set i and a is an element of the set t every context free language can be analyzed by a directed production analyzer the kuno oettinger multiple path syntactic analyzer for english is a concrete example of a directed production analyzer and of a working parsing algorithm the connection between structures assigned by the analyzer and those of a conventional phrase structure grammar is examined in this paper
CACM	final examination scheduling a method for scheduling final examinations to yield a minimal number of student conflicts is described the minimization is achieved by repetitively evaluating a nonlinear set of equations imbeded in the process is a random or monte carlo selection of assignments as in such heuristic techniques the solution may not be optimum and many solutions may be found which yield locally minimal results computer programs are described and empirical results given
CACM	machine controls for analysis of variance a major problem in using the analysis of variance as the number of factors increases is the exponential rise in the number of interactions even though the experimenter may not be interested in these interactions it is impossible to ignore them in most experimental designs because of the problem of getting error terms it is natural therefore to look to the computer to handle the bulk of work involved in computing the interactions a program device to get the computer to do this is described
CACM	near minimax polynomial approximations and partitioning of intervals a method of near minimax polynomial approximation is described as a by product this method provides a formula for an estimate of the maximum error associated with a given degree of approximation using this formula a partitioning algorithm is obtained for dividing a basic interval into subintervals for which approximations of equal degree give equal maximum error
CACM	interchangcable perforated tape variable block formats for positioning and straight cut rs 273 and contouring and contouring positioning rs 274 numerically controlled machine tools proposed american standards
CACM	comments on bit sequencing of the ascii in serial by bit data transmission
CACM	gauss algorithm 209 s15
CACM	xy move plotting algorithm 162 j6
CACM	free field read algorithm 239 i5
CACM	conjugate gradient method algorithm 238 f4
CACM	greatest common divisor algorithm 237 a1
CACM	bessel functions of the first kind algorithm 236 s17
CACM	a note on the formation of free list
CACM	a method of syntax checking algol 60 a syntax checker was designed based on the syntax of algol as described in the algol 60 report communications of the acm may 1960 since the definition of the elements of the language is recursive it seemed most desirable to design the syntax checker as a set of mutually recursive processors tied together by subroutines which perform certain bookkeeping functions because of the recursive nature of the language and of the syntax checker the problem of recovery after an error required much attention a method was devised which permits most programs to be checked completely despite errors
CACM	divide and correct methods for multiple precision division a division problem is defined and notation to relate it to the problem of multiple precision operation in a digital computer is introduced a basic divide and correct method for multiple precision division is formulated and its known properties briefly reviewed of particular interest is the fact that the method produces at each step a set of precisely three estimates for the desired result one of which is exact
CACM	an alternate checksum method
CACM	investigation of a new analytical method for numerical derivative evaluation a recently proposed analytical approach to numerical derivative evaluation is discussed the technique is shown to be both accurate and easy to apply though certain indicated modifications are required its use should greatly facilitate the writing and debugging of programs requiring derivatives of highly complex functions
CACM	a simple automatic derivative evaluation program a procedure for automatic evaluation of total partial derivatives of arbitrary algebraic functions is presented the technique permits computation of numerical values of derivatives without developing analytical expressions for the derivatives the key to the method is the decomposition of the given function by introduction of intermediate variables into a series of elementary functional steps a library of elementary function subroutines is provided for the automatic evaluation and differentiation of these new variables the final step in this process produces the desired functions derivative the main feature of this approach is its simplicity it can be used as a quick reaction tool where the derivation of analytical derivatives is laborious and also as a debugging tool for programs which contain derivatives
CACM	techniques for the simulation of computer logic the simulation of a digital computer is an integral part of most computer design automation systems the evaluation of the boolean functions which characterize the computer being simulated constitutes one major portion of a simulation system four general procedural classes for evaluating these functions are defined toward greatly increased efficiency of a simulation system methods are presented for simultaneously evaluating many functions for one set of values of the variables and for evaluating simultaneously one function for many sets of values for the variables
CACM	a note on starting the newton raphson method determination of a suitable initial estimate for a root of an equation f x 0 by means of computing the roots of a sequence of related equations is described
CACM	theoretical considerations in information retrieval systems information storage and retrieval systems are composed of three major components a identification of information and tagging it for effective retrieval b searching strategy how to enter the file to circumvent the scanning of nonrelevant material and c file organization to make access to information efficient for identification of information the paper suggests that a metalanguage recently discussed in a paper by goffman verhoeff and belzer associated with an object language be used for searching strategy a linear model for an evaluation function of relevancy is developed which rewards the system for retrieving relevant documents and not retrieving the nonrelevant and penalizes the system for the escaped relevant documents and false drops the inadequacies of a linear model are indicated two approaches to file organization are discussed one is self organization of the file based on its history and past performance and the second is a self generating subset of the file with a high probability of being relevant
CACM	experimental personalized array translator system a system designed for intimate man machine interaction in a general purpose problem solving environment is experimentally operational the system utilizers an array oriented symbolic source language containing powerful statement types these include numeric boolean relational and selection operators on operands which can be entire arrays the system also permits simple specification of test and argument arrays in single statements the completely symbolic operating system includes display and entry of program and data sequence control is aided by an interrupt switch which allows the user to interact with the program during execution in addition to normal stored program sequencing the system provides trace options and the ability to enter any statement for immediate execution present implementation of the system is with an interpretive translator on an ibm 1620 computer
CACM	autosate an automated data system analysis technique is described the technique is designed to alleviate some of the principal problems that beset current analysis large data workloads long span of time between project inception and system operational date the lack of explicit directions for conducting data system analysis and using the results and the lack of a technique to control data system changes throughout its lifetime the analysis is geared to determining workload relationships and storage characteristics of documents in the information network automatically
CACM	characteristics of the fortran cep language the fortran cep languages differs from fortran ii mainly because 1 it extends the variety of the modes for real quantities 2 it allows suitable mixtures in an input output list or in an expression of quantities that occur under different modes 3 it makes it possible to address a greater number of input output equipment and 4 it removes the restrictions on the complexity of the list of quantities to be transmitted between the magnetic core memory and the drum or the magnetic tape units
CACM	remark on further generalization of algol
CACM	reduction of a matrix containing polynomial elements algorithm 170 f3
CACM	crout with equilibration and iteration algorithm 135 f4
CACM	summation of fourier series algorithm 128 c6
CACM	romberg integration algorithm 60 d1
CACM	random permutation algorithm 235 g6
CACM	poisson charlier polynomials algorithm 234 s23
CACM	talk a high level source language debugging technique with real time data extraction talk meaning take a look is a debugging technique which aids substantially in debugging complex real time programming systems by interrupting the users program at desired points to extract previously specified data the extracted data is later edited listing the associated data with its high level source language identification
CACM	an automatic loader for subroutine nests a method for automatic loading of library subroutines which can be adapted to operate in conjunction with any conventional two pass assembler is described the method is specifically designed to cope with a nested library structure
CACM	programming analysis of variance by sequences of operators and isomorphic mappings a special operator calculus developed by hartley in 1956 together with a new mapping scheme has been found to be efficient in programming analysis of variance for multifactor experiments the operator calculus and the mapping scheme are described in detail
CACM	a compiler building system developed by brooker and morris in a number of articles published during the past two years r a brooker and d morris joined by j s rohl in their most recent paper have presented a very interesting programming system that they have developed for the ferranti atlas computer the present paper describes some of the major features of their system it expands on some points that the original authors cover briefly and treats only very lightly some topics to which they devote considerable space the purpose of this paper is purely expository except in some very small details and in some comments it does not intentionally depart from or add to the material published in the listed references
CACM	generation of test matrices by similarity transformations a method for obtaining test matrices with a prescribed distribution of characteristic roots is given the process consists of using particularly simple similarity transformations to generate full matrices from canonical forms the matrices generated also have known characteristic vectors inverses and determinants
CACM	approximate solution of axially symmetric problems a variety of physical problems in such diverse fields as electrostatic field theory heat and ideal fluid flow and stress concentration theory reduce under the assumption of axial symmetry to the study of an elliptic partial differential equation dirichlet type problems associated with this equation are studied on regions whose boundaries include a nondegenerate portion of the x axis and exceedingly accurate numerical methods are given for approximating solutions
CACM	numerical solution of nonlinear two point boundary problems by finite difference methods solution of nonlinear two point boundary value problems is often an extremely difficult task quite apart from questions of reality and uniqueness there is no established numerical technique for this problem at present shooting techniques are the easiest method of attacking these problems when these fail the more difficult method of finite differences can often be used to obtain a solution this paper gives examples and discusses the finite difference method for non linear two point boundary value problems
CACM	a parts breakdown technique using list structures list structured parts breakdown is proposed and discussed implementation facts are presented on operating program using these techniques
CACM	multiword list items the list concept as originally proposed by newell simon and shaw specified single computer words as elements of a list this report describes the use of two or more consecutive words as one element such use results in a considerable saving in both the space required to hold a given amount of data and in the execution time required to perform a given process on the data following a brief description of standard list structures with single word items the multiword items are introduced then variable length items are described along with the corresponding space utilization problems finally several examples are given to illustrate the use of multiword lists this paper attempts to draw together various recent papers which have applied some of these concepts in different ways and indicate how they relate to the more general problems
CACM	reducing truncation errors by programming in accumulating a sum such as in a numerical integration with a large number of intervals the sum itself becomes much larger than the individual addends this may produce a less accurate sum as the number of intervals is increased separate variables can be established as accumulators to hold partial sums within various distinct intervals thus the extensive successive truncations are eliminated
CACM	design and implementation of a general purpose input routine a general purpose input routine is discussed and advocated for fortran the philosophy of such programs is examined and exemplified
CACM	gauss seidel algorithm 220
CACM	q bessel functions in t algorithm 214
CACM	shellsort algorithm 201
CACM	critical path scheduling algorithm 40
CACM	simpsons rule for multiple integration algorithm 233
CACM	heapsort algorithm 232
CACM	matrix inversion algorithm 231
CACM	matrix permutation algorithm 230
CACM	symbol manipulation in fortran sasp i subroutines a set of subroutines for use in fortran are described whose purpose is to synthesize output strings from i input strings which have been analyzed by the shadow general syntactic analysis subroutine reported earlier and or ii packed bcd strings formed in any way function type subroutines are included for intermediate manipulations which are performed on the strings which are stored in an abbreviated internal representation the automatic way in which an internal representation for each newly created substring is stored sequentially in a block of common storage and the manner in which a storage block is dynamically allocated for that purpose are discussed
CACM	one inch perforated paper tape for information interchange proposed american standard
CACM	perforated tape code for information interchange proposed american standard
CACM	bit sequencing of the american standard code for information interchange ascii in serial by bit data transmission proposed american standard
CACM	growing applications of linear programming use of linear programming models has grown so extensively in recent years that the whole concept for organizing a computer code has undergone a radical change it no longer is adequate merely to reduce a mathematical algorithm i e the simplex method to a computer code an advanced code must cope with such a variety of situations that the respective computer subprograms must be organized into an integrated system emphasis in this paper is devoted to the underlying principles upon which future linear programming systems must be based these viewpoints are influenced by the new demands that applications within the petroleum industry are placing on such systems some of the components of such a system are translation of problem statement in terms of basic data to linear programming matrix coefficients data transmission for direct computer entry data file at the computer center data processing and editing prior to solving the simplex algorithm an efficient and reliable code for solving the above mentioned algorithm and flexible means for summarizing the results
CACM	picture generation with a standard line printer a method is described for producing gray toned pictures on a line printer by utilizing the different degrees of blackness of standard print characters gray scales with 17 32 and 64 levels have been devised scanned images of blood cells are used to display the technique
CACM	a fortran ii load time saver
CACM	a method for comparing the internal operating speeds of computers
CACM	expand a system for input card replication
CACM	computer usage accounting for generalized time sharing systems the current development of general time sharing systems requires a revision of accounting procedures for computer usage since time sharing system users operate concurrently it is necessary to be more precise as to the amount of computer time and storage space that a user actually utilizes the various cost factors which should be considered for computer usage accounting in generalized time sharing systems are discussed
CACM	an improved equivalence algorithm an algorithm for assigning storage on the basis of equivalence dimension and common declarations is presented the algorithm is based on a tree structure and has reduced computation time by 40 percent over a previously published algorithm by identifying all equivalence classes with one scan of the equivalence declarations the method is applicable in any problem in which it is necessary to identify equivalence classes given the element pairs defining the equivalence relation
CACM	a fast procedure for generating exponential random variables a very fast method for generating exponential random variables in a digital computer is outlined
CACM	shanks algorithm 215
CACM	shuttlesort algorithm 175
CACM	multiple integration algorithm 146
CACM	chebyshev curve fit algorithm 91
CACM	elementary functions by continued fractions algorithm 229
CACM	q bessel functions algorithm 228
CACM	chebyshev polynomial coefficients algorithm 227
CACM	normal distribution function algorithm 226
CACM	gamma function with controlled accuracy algorithm 225
CACM	an experiment in a user oriented computer system a version of a software hardware system for the purpose of facilitating the programming and analysis of well formulated problems is described a modified flexowriter is used to generate computer acceptable input when equations or computable requests are typed in much the same manner as they would appear in conventional mathematical texts the typing and language rules are quite flexible and unrestrictive while the compiler part is efficient the system as a whole has much broader aspects as a tool for the study of problem solving and self teaching systems
CACM	on declaring arbitrarily coded alphabets the inability of existing programming languages to handle character strings from more than one or two alphabets is mentioned and a scheme for declaring additional alphabets is proposed the scheme provides for many to one encodings right or left justification collating sequences different from numeric sequence variations in character size number of bits from alphabet to alphabet and arbitrary source language character representation
CACM	specification for general purpose paper cards for information processing proposed american standard
CACM	a proposal for input output conventions in algol 60 a report of the subcommittee on algol of the acm programming language committee
CACM	problems in automatic abstracting a variety of problems concerning the design and operation of an automatic abstracting system are discussed the purpose is to a general view of several major problem areas no attempt is made to discuss details or to indicate preferences among alternative solutions
CACM	menu planning by computer a computer code has been developed which plans menus by finding minimum cost combinations of menu items such that the daily dietary gastronomic and production requirements can be satisfied for a sequence of days a fast special integer programming algorithm is described which approximates the theoretical solution to the problem if necessary any menu can be changed on line and then post optimized up to 30 percent saving on food cost is possible a fortran program for the ibm 1410 is available on request a considerable amount of data processing must precede the implementation of the system
CACM	designing a computer center
CACM	incomplete beta function ratios algorithm 222
CACM	hypergeometric and confluent hypergeometric algorithm 191 192
CACM	nonrecursive adaptive integration algorithm 182
CACM	evaluation of determinant algorithm 224
CACM	prime twins algorithm 223
CACM	decimal tables of binary coded tables
CACM	on avoiding matrix reversals between 7090 fortran ii and 7090 fortran iv
CACM	an algorithm for converting integers from base a to base b a little known simple algorithm for integer conversion between number systems is presented and proved
CACM	a comparison of list processing computer languages including a detailed comparison of comit ipl v lisp 1 5 and slip a detailed comparison is presented of comit ipl v lisp 1 5 and slip   four well known computer programming languages which among them exhibit all the principal characteristics of existing list processing languages important common features of list processing languages are reviewed forms of data structures which are manipulated necessity for dynamic allocation of storage use of pushdown stores and use of recursive operations principal differences between the four languages under consideration are detailed representations of data both by the programmer and within the machine methods for storage allocation programming formalisms and special processes available including arithmetic facilities and usability in terms of availability documentation learning aids and debugging facilities a rough comparison shows that all the languages discussed have approximately the same speed finally the authors give some heuristics to aid in the selection of one of these languages for use in particular problem applications concluding that no one of the languages considered is distinctly superior in all possible list processing applications
CACM	professional computer work for the blind developments in computer technology have opened new professional opportunities for the intelligent blind since there are few if any occupations in which the blind can participate without serious disadvantage the opportunities offered them to gain entrance into various occupations through computer use including that of programmer is important for future rehabilitation planning also of immediate interest is the fact that the blind may be especially suited for programming work because of intense training in and constant experience with locating objects in the unseen environment and also because of superbly trained memory the blind brings to the work of programming skills which the sighted has had little need to acquire these qualifications should result in fewer debugging problems and make the blind a valuable addition to any systems group before the blind could become a serious professional a number of aids and techniques had to be developed that can mediate between machines and programmer this paper describes the techniques and aids which were designed by the staff of the medical computing center of the university of cincinnati college of medicine
CACM	status of computer sciences curricula in colleges and universities
CACM	the place of logical design and switching theory in the computer curriculum
CACM	mechanical languages a course specification
CACM	logic for the computer sciences
CACM	an undergraduate curriculum in numerical analysis
CACM	on introducing digital computing
CACM	programming of digital computers
CACM	computers and education
CACM	digital data processor for tracking the partially illuminated moon a study of lunar tracking techniques and fabrication of a breadboard to assess the feasibility of the best technique selected was conducted to define a tracking system for observation of the sight line to the center of a partially illuminated moon the data processing portion of the system is presented in detail and then described in general are the operation of the tracker head assembly for data readout the operation of the entire system and the effect data processing considerations have on the design of the tracker system the system basically consists of an optical sensor digital computer and tracker drive mechanism the three system units connected in cascade comprise the control loop for this application an optical telescope with a radial mechanical scanning mechanism was used that read out lunar sight line measurement information this information is sequentially read into a special purpose digital computer that extracts the measurements and computes the error signals that drive the tracker to the appropriate attitude
CACM	conversion of a power to a series of chebyshev polynomials even slowly convergent power series can be rearranged as series in chebyshev polynomials if appropriate sequence transformations are used in evaluating the coefficients the method is illustrated by computing the coefficients for the expansion of the logarithm and dilogarithm
CACM	a fourier series method for the numerical solution of a class of parabolic partial differential equations a fourier series method is described which when applied to a certain class of parabolic partial differential equations reduces the problem to a system of ordinary differential equations an application is given for which the method shows a considerable advantage over conventional finite difference methods
CACM	a class of iterative techniques for the factorization of polynomials a method of iteration is developed in terms of a function of somewhat arbitrary character sufficient conditions are given for convergence of the process yielding factors of arbitrary degree for polynomials in one variable both lins method and newtons method occur as special cases
CACM	a technique for computer detection and correction of spelling errors the method described assumes that a word which cannot be found in a dictionary has at most one error which might be a wrong missing or extra letter or a single transposition the unidentified input word is compared to the dictionary again testing each time to see if the words match assuming one of these errors occurred during a test run on garbled text correct identifications were made for over 95 percent of these error types
CACM	computer made perspective movies as a scientific and communication tool it is easy to program the basic transformation required for a perspective drawing this fact plus the advent of high speed microfilm printers such as the general dynamics electronics s c 4020 makes possible perspective movies as the direct output from a computer the programming of such a movie is briefly described for studying the angular motions of a satellite containing an attitude control system in the movie a domino shaped box represents the satellite and a sphere with circles of latitude and longitude represents the earth the cost was approximately three to eight minutes of ibm 7090 time per one minute of movie
CACM	generating a canonical prefix encoding computer programs for generating a minimum redundancy exhaustive prefix encoding are described one program generates a huffman frequency tree another determines the structure functions of an encoding and a third program assigns codes
CACM	randomized binary searching with tree structure a more efficient method of using tree structures is proposed which utilizers both plus and minus branches in the search path very significant gains result when the search key includes alphabetic characters
CACM	tests on a computer method for constructing school timetables a previously proposed computer method for constructing timetables based on an iteration involving boolean matrices is described in limited tests the method has successfully produced timetables on every trial references are given which relate the timetable problem to theorems on matrices of zeros and ones and to theorems on bipartite graphs some problems of applying the method to constructing timetables in real situations are noted
CACM	polyphase sorting with overlapped rewind a variation of the polyphase merge technique of sorting is described which permits one tape at a time to be rewound while the merge is continued on the remaining tapes the result is the overlapping of a major portion of the rewind time the technique should be considered whenever a sort is written to operate on five or more tapes that cannot be read backwards the savings of the overlap method appear to increase as the number of available tapes is increased
CACM	fortran subroutines for time series data reduction
CACM	an open letter to x3 4 3 fortran standards    american association
CACM	alcor group representations of algol symbols comm acm 6 1963 597 599 corrigenda
CACM	comments on a continued operation notation this note is intended to clarify and correct several points in a recent paper describing some notations for symbol manipulation by m p barnett comm acm 6 august 1963
CACM	a note on some compiling algorithms two compiling generators for arithmetic expressions are discussed one presently in use in an experimental compiler and an improvement suggested by k speierman of burroughs
CACM	gauss algorithm 209
CACM	matrix division algorithm 197
CACM	syminv2 algorithm 150
CACM	erf algorithm 123
CACM	tridiagonal matrix algorithm 122
CACM	evaluation of determinant algorithm 41
CACM	incomplete beta function ratios algorithm 222
CACM	gamma function althm 221
CACM	on context and ambiguity in parsing
CACM	an extension to algol for manipulating formulae
CACM	a programming package for some general modes of arithmetic
CACM	some effects of the 6600 computer on language structures the problem of compiling efficient 6600 codes prompted the development of an intermediate language reflecting the structure of the machine that is more easily manipulated in improving object program efficiency the subject of this paper is the intermediate language and methods of manipulating it compilations of a series of arithmetic statements are discussed it is assumed that all functions and exponentials have been removed from these statements and replaced by simple variables for purposes of simplicity the treatment of subscripts is ignored a simplified 6600 structure is presented to illustrate the compiling method several assumptions are made for purposes of simplification although there are cases in which the assumptions are violated in the actual machine
CACM	a general business oriented language based on decision expressions the structure of a digital compute programming language which covers a wide class of business and file processing applications is presented such a structure based on identifying and incorporating into a compiler the aspects common to all processes of such class permits writing extremely compact programs even for comparatively complex applications in terms of tables of control expressions which express only information characteristic of the particular application furthermore local changes of a process e g changes affecting only one of the output files involved can be effected by local modifications in the program e g modification of only one entry of the tables this structure also allows for inexpensive preparation of loading speed compilers which translate the source programs into efficient machine codes the approach adopted here departs from conventional mechanical language design philosophies it stresses the structural analysis of the class of processes to be represented in the languages as opposed to emphasizing formal i e contents independent syntactical definitions it relies exclusively on nonprocedural representation of process as sets tables of relations between data and results there are no control statements such as go to etc instead of using procedure descriptions which are one to one translations of flowcharts here an invariant pattern of procedure is identified as characteristic of the class of all batch file processes this new philosophy has the potential to overcome well known deficiencies of other business oriented languages and fully meets the requirements set by codasyl for such languages including machine independence
CACM	beginnings of a theory of information handling
CACM	a format language
CACM	formalism in programming languages
CACM	fortran iv as a syntax language
CACM	structural connections in formal language
CACM	bounded context syntactic analysis
CACM	an extension of algol like languages
CACM	analysis of decay type data a comparative study has been made of a variety of numerical techniques for fitting experimental data of the decay type by forms involving the sums of exponentials statistical errors of the fitted parameters are also calculated these methods have been applied to artificially generated sets of data as well as to the results of experiments with radioactive tracers on both human and animal subjects results show that the values of the fitted parameters are very sensitive to variations in the fitting procedure therefore great care very sensitive to variations in the fitting procedure therefore great care must be exercised in identifying such values with physical constants although the values of functions derived from these fitted parameters which can definitely be associated with physical entities are generally more stable under variations in the fitting techniques error bounds can be so large that no great confidence can be placed even in them it would therefore appear best to select a uniform technique both for running the experiments and for analyzing the data and then to consider as significant only relative results between one subject and the next
CACM	digital computer determination of alpha source activity a technique is described for determining the activity and homogeneity of an alpha source it is believed that the technique using a digital computer has many uses and applications in the field of nuclear physics the technique involves computer manipulation of the digital image of the nuclear source experimental details are given
CACM	git a heuristic program for testing pairs of directed line graphs for isomorphism given a pair of directed line graphs the problem of ascertaining whether or not they are isomorphic is one for which no efficient algorithmic solution is known since a straightforward enumerative algorithm might require 40 years of running time on a very high speed computer in order to compare two 15 node graphs a more sophisticated approach seems called for the situation is similar to that prevailing in areas such as game playing and theorem proving where practical algorithms are unknown for the interesting cases but where various practical though only partially successful techniques are available git graph isomorphism tester incorporates a variety of processes that attempt to narrow down the search for an isomorphism or to demonstrate that none exists no one scheme is relied upon exclusively for a solution and the program is designed to avoid excessive computation along fruitless lines git has been written in the comit language and successfully tested on the ibm 7090
CACM	an efficient composite formula for multidimensional quadrature a 2s 1  point second degree quadrature formula for integration over an s dimensional hyper rectangle is presented all but one of the points lie on the surface with weights of opposite sign attached to points on opposite faces when a large volume is subdivided into congruent rectangular subdivisions only one point is required in each interior subdivision to achieve second degree accuracy
CACM	on the numerical solution of boundary value problems for linear ordinary differential equations a numerical method is presented for the solution of boundary value problems involving linear ordinary differential equations the method described is noniterative and makes use of any one step numerical integration scheme to reduce the problem from one of boundary values to one of initial values comments are made concerning some numerical results of applying the method to a specific problem in addition an extension of the algorithm described to more general problems is discussed
CACM	an example in significant digit arithmetic different methods of handling the summing process for the geometric series are shown to give results indicating widely differing significances when carried out in a machine incorporating significant digit arithmetic
CACM	gargoyle a language for compiler writing
CACM	a fortran post mortem procedure
CACM	a note on multiplying boolean matrices ii
CACM	floating point arithmetic with 84 bit numbers a classic and straightforward technique is presented which is not limited to the size or type of number representation used or multiple precision arithmetic
CACM	a fast procedure for generating normal random variables a technique for generating normally distributed random numbers is described it is faster than those currently in general use and is readily applicable to both binary and decimal computers
CACM	multi tape and infinite state automata    a survey a survey of machines which are more powerful than finite automata and less powerful than general turing machines is presented it is felt that the machines in this category are as closely related to digital computers as either the finite automata or the unrestricted turing machines intermediate machines can be created by adjoining on infinite state memory to a finite state machine and then performing any or all of the following 1 restrict the manner in which the unbounded portion of the memory can be accessed 2 bound the number of steps allowed for a computation by some increasing recursive function of the length of the input 3 restrict the total amount of memory available in the same manner examples from all three classes and their properties are discussed
CACM	experiments with a deductive question answering program as an investigation in artificial intelligence computer experiments on deductive question answering were run with a lisp program called deducom an acronym for deductive communicator when given 68 facts deducom answered 10 questions answerable from the facts a fact tells deducom either some specific information or a method of answering a general kind of question some conclusions drawn in the article are 1 deducom can answer a wide variety of questions 2 a human can increase the deductive power of deducom by telling it more facts 3 deducom can write very simple programs it is hoped that this ability is the forerunner of an ability to self program which is a way to learn 4 deducoms search procedure at present has two bad defects some questions answerable from the given facts cannot be answered and some other answerable questions can be answered only if the relevant facts are given in the right order 6 at present deducoms method of making logical deductions in predicate calculus has two bad defects some facts have to be changed to logically equivalent ones before being given to deducom and some redundant facts have to be given to deducom
CACM	hankel function algorithm 124 s17
CACM	procedure for the normal distribution functions algorithm 272 s15
CACM	program structures for parallel processing constructs for organizing and explicating parallel program segments are discussed as extensions to algol 60 the constructs serve as meta commands and are motivated by equipment having multiprocessing capability
CACM	machine independence its technology and economics a survey is offered of techniques for transferring programs and especially compilers from one computer to another of the methods examined the bootstrap technique is singled out for detailed discussion with emphasis on its economics the considerations that determine the applicability of bootstrapping in any specific case are discussed and an attempt is made to assign appropriate qualitative weights to them finally reasons are given for believing that the machine independence problem is being substantially diminished by current trends in computer design and that it is this process of convergence in hardware design rather than any foreseeable software developments that will lead to its satisfactory resolution
CACM	cat a 7090 3600 computer aided translation a semi automatic translation system has been implemented which converts 7090 fap language programs into 3600 assembly language the input to the system is a fap program deck which has been specially prepared for translation by the user the output consists of the translated compass language program together with a comprehensive diagnostic listing which the user must analyze in order to verify any questionable areas of the translation the translation processor consists of three distinct phases an assembly of the fap program a comprehensive analysis of the assembled code with particular regard to the actions of instructions upon other instructions and upon data and finally the output pass which generates the compass program in the form of macro instructions
CACM	1401 compatibility feature on the ibm system 360 model 30 the second generation of stored program computers of which ibm 1400 series was a part brought edp into the mass market for the first time on a large scale as this era unfolded rapid changes in technology led to rapid obsolescence of data processing equipment program written for a particular system required tedious conversion as incompatible new machines came into use the ibm system 360 has been designed with the conversion problem specifically in mind one of the conversion aids available on the model 30 is the 1401 compatibility feature this feature in conjunction with other aids permits a smooth and inexpensive transition to optimum use of the new system
CACM	an assembly language for reprogramming complete reprogramming of compiler language programs is seldom necessary it is assembly language programs which present the greatest difficulty assembly languages generally provide a one for one translation from a symbolic to a numeric version of a program that is from assembly language to machine language the meta language presented here can be used to specify the mapping of any language which conforms to a canonical list form into an arbitrary stream of bits this bit stream may be treated as a machine language program a character stream or whatever else the user might desire thus this meta language can be used to map from one assembly language into another or from the assembly language for one machine into the machine language of another
CACM	philco ibm translation at problem oriented symbolic and binary levels a translation system has been developed to eliminate most of the effort formerly required to reprogram philco 2000 series codes for ibm 7094 operation experience with this system is limited but highly successful encouraging application of the techniques to other source and object languages
CACM	emulation of large systems the conversion problem and a new technique called emulation are discussed the technique of emulation is developed and includes sections on both the central processing unit cpu and the input output unit i o this general treatment is followed by three sections that describe in greater detail the implementation of compatibility features using the emulation techniques for the ibm 7074 7080 and 7090 systems on ibm system 360
CACM	the spectra 70 45 emulator for the rca 301 the rca 301 emulator system is supplied with the spectra 70 45 as a reprogramming aid it allows an rca 301 object program to be run on the spectra 70 45 without necessitating changes in the rca 301 object code execution rates are considerably better than traditional simulation the emulator provides an increase in throughput capacity for the 301 user on the spectra 70 45 the emulator makes use of both hardware micro program routines and software routines to accomplish its function
CACM	a use of macros in translation of symbolic assembly language of one computer to another a set of macro operations has been prepared to assist in translating ibm 7090 symbolic assembly language programs to ibm 7040 machine language programs this set inserted at the beginning of the 7090 symbolic deck treats incompatible instruction mnemonics as macro instructions to produce equivalent 7040 instruction sets incompatible instructions are categorized into basic operational classes which can be expressed by a single basic skeleton several levels of macro calls are required to supply arguments to the basic skeleton for each particular instruction modification at execution time of the address or tag of an incompatible instruction requires incorporation of an address tag equivalent i o is handled by generating calls to i o simulation subroutines
CACM	on the translation of machine language programs automatic translation of machine language programs is becoming a highly desirable goal with the advent of new large scale computers the pitfalls that make it difficult to achieve completely automatic translations are analyzed and it is shown that these are primarily of a semantic nature a semi automatic procedure for resolving semantic problems is suggested
CACM	across machine lines in cobol the production of a large file maintenance and retrieval program system written in cobol is described the cobol language was used specifically to enable the system to operate on three ibm computers
CACM	an algorithm for minimizing backboard wiring functions a partially exhaustive algorithm is presented for solving the following problem arising from automatic layout of a computer given an ordered set e1 e2 en of n computer components for each permutation of the elements e1 e2 en there is attached a value of an integer function f the algorithm finds a local minimum of f by evaluating the set delta f of the increments corresponding to a certain set of exchanges of two elements then the exchange corresponding to the least negative increment of delta f is performed the process is iterated and stopped when the set of the increments is a positive or empty set which it is proved corresponds to a minimum the procedure is similar to the downhill method for finding the minimum of a real function f p and can be applied to other placement problems experimental results are presented with backboards formed by many elements and different initial placements
CACM	analyzing english syntax with a pattern learning parser a dependency analysis system based on pattern recognition and learning logic was developed to infer word classes and rules of syntactic combination from experience with text which had been analyzed the characteristics used to form word classes are the depth in the dependency tree of each word the direction of its governor and the same features for each of its immediate neighbors syntactic rules of combination show the relation of a word to its governor in the depth pattern of the sentence the system was tested on 400 elementary basic english sentences including 300 used earlier by knowlton in a different learning parser of all 400 sentences after experience with 300 sentences it was able to generalize with 77 percent accuracy to the next 100 in accumulative learning trials after the first 200 sentences it averaged a probability of 9 for accurately parsing each new sentence it encountered it was concluded that the system is adequate for learning to parse the bulk of basic english but that further development is required before conclusions about its application to ordinary english can be stored the system is operational and available on the arpa sdc time shared computing system
CACM	a comparison of the primal simplex and primal dual algorithms for linear programming a statistical comparison of the primal dual and the more commonly used primal simplex algorithm for solving linear programming problems has been made under the assumption of starting with a full artificial basis under these conditions the primal dual method shows a statistically significant superiority on randomly generated problems it has also been found via a regression analysis that the relevant parameters in determining the difference in the number of iterations between the algorithms is not only the number of constraints and the number of variables but also the ratio of the latter to the former
CACM	conversion of limited entry decision tables to computer programs decision tables are useful for describing a set of complex decision rules based on given sets of conditions algorithms that can efficiently convert the tables into computer programs will extend the usefulness of decision tables to computer users two such algorithms based on work done by m s montalbano are described and extended here to handle dashes and else decision rules the first algorithm minimizes the computer storage space required for the resultant program the second minimizes computer running time during the conversion process both pinpoint any contradictions or redundancies among the rules in a table
CACM	the performance of a system for automatic segmentation of programs within an algol compiler gier algol the gier algol compiler makes use of an automatic system for handling the transfers of program segments from the drum store to the core store at program execution time the logic of this system is described the performance of the system is discussed primarily on the basis of execution times related to two specific programs this discussion concludes with an assessment of the potential gains of various ways of improving the system
CACM	inverse permutation algorithm 250 g6
CACM	quickersort algorithm 271 m1
CACM	finding eigenvectors by gaussian elimination algorithm 270 f2
CACM	determinant evaluation algorithm 269 f3
CACM	algol 60 reference language editor algorithm 268 r2
CACM	pufft the purdue university fast fortran translator a core resident compile and go system designed for the ibm 7090 7094 computer is described in little more than half of the 32k word core memory pufft provides a monitor for job sequencing a translator for the full fortran iv language the fortran subroutine library an input  output system for use at compile time and at execute time and a rather elaborate diagnostic message writing routine batches of small  and medium sized fortran iv source language programs are processed at very high speeds language compatibility has been maintained so that programs may be debugged in the pufft system and then recompiled and run in the ibjob ibftc system supplied by the manufacturer
CACM	axle an axiomatic language for string transformations axle is a language designed for data manipulation data arranged in a linear form in a workspace is transformed according to a table of axioms called imperatives a transformation consists of a matching procedure which decides where an imperative is applicable and a replacement procedure that modifies that part of the workspace imperatives are applied in accordance with definitions of symbolic terms presented systematically in an assertion table the process of definition includes the special case of recursive assertions several complete programs of imperatives are given to show a few applications of the language
CACM	a simple data transmission system using the office telephone a method has evolved for transmitting data of a type originating in many laboratory situation direct to a central computer the method requires almost no specialized equipment and uses any ordinary telephone on a callup basis present applications include cardiac output calculations radio activity tracer studies and neurophysiology time sequence studies of nerve impulses
CACM	contextual correlates of synonymy experimental corroboration was obtained for the hypothesis that the proportion of words common to the contexts of word a and to the contexts of word b is a function of the degree to which a and b are similar in meaning the shapes of the functions however indicate that similarity of context is reliable as criterion only for detecting pairs of words that are very similar in meaning
CACM	a note on the use of a digital computer for doing tedious algebra and programming a special purpose compiler was written with fortran ii language and made possible the writing of very long programs by the computer the procedure is based on a straight forward use of format statements for generating machine written programs
CACM	a fast storage allocator a fast storage bookkeeping method is described which is particularly appropriate for list structure operations and other situations involving many sizes of blocks that are fixed in size and location this scheme used in the llllll or l6 bell telephone laboratories low level list language makes available blocks of computer registers in several different sizes the smaller blocks are obtained by successively splitting larger ones in half and the larger blocks are reconstituted if and when their parts are simultaneously free
CACM	a program to solve the pentomino problem by the recursive use of macros a coding technique is described in which certain macro instructions are given lists as arguments and are thereby used recursively the discussion covers primarily an example in which the technique is used to solve the pentomino problem the problem of fitting 12 pentominos without overlapping into a plane area formed of 60 elemental squares
CACM	recursive solution of a class of combinatorial problems an example combinatorial problems requiring the selection of n elements from a set of m elements may be solved by a recursion process analogous to that for computing binomial coefficients several specific problems are analyzed the general technique is exposed and an algol program is developed for one of the problems
CACM	note on an ascii octal code table standards
CACM	an algol like computer design language the idea of constructing a computer design language by making use of an algol like programming language is presented a computer designer can benefit from using a design language at a higher level just as a computer user can benefit from a higher level programming language the purposes and requirements of the design language are enumerated to achieve most of the purposes a translator is required to translate a design of computer logic into a set of boolean equations the design language is presented in terms of vocabulary statements sequences and microprogram included are examples of identifiers expressions with both unary and binary operators declaration statements transfer statements terminal statements exchange statements if statements do statements go to statements several sequences and a microprogram
CACM	random normal deviate algorithm 267 g5
CACM	pseudo random numbers algorithm 266 g5
CACM	find precedence functions algorithm 265 l2
CACM	interpolation in a table algorithm 264 e1
CACM	gomory 1 algorithm 263 h
CACM	establishment of the acm repository and principles of the ir system applied to its operation the history of the establishment of the acm repository at the moore school university of pennsylvania is reviewed briefly two principles are presented as paramount in the provision of information services 1 easy accessibility to the information files by users unfamiliar with file organization and 2 value of service exceeding user costs these principles serve as guides in mechanizing the acm repository the main features of the information system are direct user access via on line teletypewriter console direct user access to all details of the system organization unrestricted and expandable search vocabulary user access through many facets of document indexing and stochastic search through linked index terms and other file relationships the first contribution to the acm repository consisted of 315 documents relating primarily to early research on compilers these documents have been cataloged and indexed and the catalog is scheduled to appear in computing reviews the indexing system is described in detail the main catalog is used to describe the documents and inverted lists are provided by the repository system for retrieval by concept coordination
CACM	uplifts university of pittsburgh linear file tandem system a series of computer programs has been developed and is now operational for processing the national aeronautics and space administration linear file system on an ibm 1401 7090 combined data processing system the program are note worthy in that they create fixed length logical records and fixed length blocks from variable length source data and format the output for optimization of processing on the ibm 7090 system the programs are completely self checking and test for both validity and accuracy of the input materials as provided by the national aeronautics and space administration
CACM	applications of differential equations in general problem solving a large class of problems leading to digital computer processing can be formulated in terms of the numerical solution of systems of ordinary differential equations powerful methods are in existence for the solution of such systems a good general purpose routine for the solution of such systems furnishes a powerful tool for processing many problems this is true from the point of view of ease of programming ease of debugging and minimization of computer time a number of examples are discussed in detail
CACM	finding zeros of a polynomial by the q d algorithm a method which finds simultaneously all the zeros of a polynomial developed by h rutishauser has been tested on a number of polynomials with real coefficients this slowly converging method the quotient difference q d algorithm provides starting values for a newton or a bairstow algorithm for more rapid convergence necessary and sufficient conditions for the existence of the q d scheme are not completely known however failure may occur when zeros have equal or nearly equal magnitudes success was achieved in most of the cases tried with the failures usually traceable to the equal magnitude difficulty in some cases computer roundoff may result in errors which spoil the scheme even if the q d algorithm does not give all the zeros it will usually find a majority of them
CACM	solution of a problem in concurrent programming control a number of mainly independent sequential cyclic processes with restricted means of communication with each other can be made in such a way that at any moment one and only one of them is engaged in the critical section of its cycle
CACM	a computer center simulation project todays computation centers are based on rapidly changing technologies of hardware and software systems it is difficult therefore to base decisions on experience in most instances the benefits of comparable experience for a given problem situation are not available in this paper a mathematical model of the lockheed central computer center is formulated that describes the operation of a computation center in terms of information nets decision processes and control functions experiments performed with this model the results of the experiments and the application of the results are discussed
CACM	on reversible subroutines and computers that run backwards a computer design is describe which permits subroutines to be executed backward as well as forward either with their instructions unchanged or replaced with conjugate instructions it is shown that using this concept a number of new subroutine types can be developed with rather unusual properties since these properties are analogous to certain matrix operations a parallel nomenclature is suggested for their classification
CACM	generation of permutations in lexico graphical order algorithm 202 g6
CACM	normal random algorithm 200 g5
CACM	normdey algorithm 121 g5
CACM	character structure and character parity sense for serial by bit data communication in the american standard code for information interchange proposed american standard
CACM	an undergraduate program in computer science preliminary recommendations
CACM	the self judgment method of curve fitting a computer oriented method for processing and communicating numerical data is described the instrument reliability factors irf which exactly define the limits of reliability of each measured item of information are used to compute the maximum permitted error mpe associated with each values of each ordinate the self judgment principle sjp is used to discard wrong information and to compute mean values of the parameters and their mpes in terms of the irf data compatibility tests with any number of different equations can be made quickly otherwise intractable problems are easily solved and the design of many experiments is greatly simplified the computational and mathematical techniques used to reduce bias in the sjp are discussed inadequacies in the statistical and graphical methods of curve fitting are noted
CACM	remarks on simulation of boolean functions
CACM	simulation of computer logic by fortran arithmetic
CACM	negative and zero subscripts in fortran ii programming for the ibm 1620
CACM	file handling within fortran this note describes some fortran subroutines to facilitate handling of tape files they allow symbolic naming of information files without violating the casual scientific programmers idea of simplicity some comments on two years use of these subroutines are given
CACM	a note on storage of strings a method for storing strings is described which uses blocks of indefinite size and is therefore completely dynamic its relation to similar schemes is discussed
CACM	non linear extrapolation and two point boundary value problems it is suggested that the convergence properties of the usual picard successive approximation scheme may be improved through use of non linrar extrapolation techniques a numerical example is provided
CACM	dynamic format specifications the use and implementation of two new fortran format conversions are discussed these format types give the fortran programmer control of input output specifications at execution time
CACM	some experiments in algebraic manipulation by computer a set of subroutines to allow algebraic manipulations on the ibm 7094 computer has been written a list processor slip a series of four problems of increasing difficulty were solved using these routines
CACM	some techniques used in the alcor illinois 7090 an algol compiler has been written by the alcor group for the ibm 7090 some little known but significant techniques in compiler writing together with organizational details of this compiler are described timing estimates and an indication of compiler requirements are also given
CACM	symbolic derivatives without list processing subroutines or recursion a routine has been developed which computes and prints out the symbolic derivative of an absolutely continuous elementary function of one or several variables no use is made of list processing languages the chain rule is applied and the result is edited to produce results as elegant and efficient as those obtained by hand computation a subset may be imbeded in a formula translator to introduce a differentiation operator into an algebraic programming language
CACM	map of partitions into integers algorithm 264 a1
CACM	partition generator algorithm 263 a1
CACM	number of restricted partitions of n algorithm 262 a1
CACM	9 j symbols algorithm 261 z
CACM	6 j symbols algorithm 260 z
CACM	legendre functions for arguments larger than one algorithm 259 s16
CACM	high speed compilation of efficient object code a three pass compiler with the following properties is briefly described the last two passes scan an intermediate language produced by the preceding pass in essentially the reverse of the order in which it was generated so that the first pass is the only one which hasto read the bulky problem oriented input the double scan one in either direction performed by the first two passes allows the compiler to remove locally constant expressions and recursively calculable expressions from loops and to do the important part of common subexpression recognition optimization such as the effective use of index registers although as important is not discussed since the object code which would be most efficient is highly machine dependent the discussion is in terms of a fortran like language although the technique is applicable to most algebraic languages
CACM	determining a computing center environment an investigation is described in which several generally unavailable parameters descriptive of a computing center environment are obtained the actual data collection and reduction is described and the results of one month of this collection are tabulated and summarized
CACM	the predictive analyzer and a path elimination technique some of the characteristic features of a predictive analyzer a system of syntactic analysis now operational at harvard on and ibm 7094 are delineated the advantages and disadvantages of the system are discussed in comparison to those of an immediate constituent analyzer developed at the rand corporation with robinsons english grammar in addition a new technique is described for repetitive path elimination for a predictive analyzer which can now claim efficiency both in processing time and core storage requirement
CACM	the organization of structured files a data file is an integral part of a data processing system in many systems the selection of an organization for the data within the file can be critical to the systems operating efficiency this paper provides the systems designer with an information source which describes ten techniques that may be employed for organizing structured data the characteristics of the organizations described are application independent thus providing the designer with a reference which allows him to limit the number of file organizations he must consider for his system
CACM	transport algorithm 258 h
CACM	treesort 3 algorithm 245 m1
CACM	random permutation algorithm 235 g6
CACM	method for hyphenating at the end of a printed line a description of a method of hyphenation is presented as a result of application of several general rules the character sets considered by the routine and the method are briefly outlined
CACM	peephole optimization redundant instructions may be discarded during the final stage of compilation by using a simple optimizing technique called peephole optimization the method is described and examplesare given
CACM	representation of the standard ecma 7 bit code in punched cards ecma standard
CACM	conventions for the use of symbols in the preparation of flowcharts for information processing systems a standard working paper this paper is intended as an outline of the various conventions which are being considered for the use of flowcharts for information processing systems the conventions are applied to the use of the symbols appearing in the proposed american standard flowchart symbols and not with the symbols per se
CACM	the structure of yet another algol compiler a high speed top down method of syntax analysis which completely eliminates back up of the source string has been implemented in a convenient macro language a technique of simulation at compile time of the use of a conventional run time stack enables the generation of code for expressions which minimizes stores fetches and stack pointer motion at run time while properly trating recursion and side effects of procedures block structure and recursion are handled without need for interpretive methods at run times the context problem in the transmission to recursive procedures of parameters called by name is solved in a manner which permits the handling of the common cases of simple expressions and array identifiers with particular efficiency
CACM	a stochastic approach to the grammatical coding of english a computer program is described which will assign each word in an english text to its form class or part of speech the program operates at relatively high speed in only a limited storage space about half of the word events in a corpus are identified through the use of a small dictionary of function words and frequently occurring lexical words some suffix tests and logical decision rules are employed to code additional words finally the remaining words are assigned to one class or another on the basis of the most probable form classes to occur within the already identified contexts the conditional probabilities used as a basis for this coding were empirically derived from a separate hand coded corpus on preliminary trials the accuracy of the coder was 91 to 93 with obvious ways of improving the algorithm being suggested by an analysis of the results
CACM	the smart automatic document retrieval system an illustration a fully automatic document retrieval system operating on the ibm 7094 is described the system is characterized by the fact that several hundred different methods are available to analyze documents and search requests this feature is used in the retrieval process by leaving the exact sequence of operations initially unspecified and adapting the search strategy to the needs of individual users the system is used not only to simulate an actual operating environment but also to test the effectiveness of the various available processing methods results obtained so far seem to indicate that some combination of analysis procedures can in general be relied upon to retrieve the wanted information a typical search request is used as an example in the present report to illustrate systems operations and evaluation procedures
CACM	conversion of decision tables to computer programs several translation procedures for the conversion of decision tables to programs are presented and then evaluated in terms of storage requirements execution time and compile time the procedures are valuable as hand coding guides or as algorithms for a compiler both limited entry and extended entry tables are analyzed in addition to table analysis the nature of table oriented programming languages and features is discussed it is presumed that the reader is familiar with the nature of decision tables and conventional definitions
CACM	a technique for integrated reports from a multi run system the requirements of a requisition accounting system for the san francisco overseas supply agency osa included exception reporting to osa itself the simultaneous satisfaction of the reporting requirement and the accounting requirements posed definite problems in system design particularly the handling of the reporting function a practical and satisfactory solution was developed by expanding the basic system with two tailored service runs for report production these two runs permitted a final system that was easier to debug easy to maintain efficient in production and responsive to the changing requirements of osa
CACM	graycode algorithm 246 z
CACM	transport algorithm 258 h
CACM	havie integrator algorithm 257 d1
CACM	modified graeffe method algorithm 256 c2
CACM	testing the understanding of the difference between call by name and call by value in algol 60
CACM	bit manipulation in fortran language
CACM	a fortran n ary counter
CACM	deeply nested iterations
CACM	an operating environment for dynamic recursive computer programming systems presented in this paper is a brief nontechnical introduction to oedipus a computer programming system which can serve as an operating environment for dynamic and or recursive programs and programming systems the available services include dynamic allocation of storage for contiguous blocks of arbitrary size input and output for a hierarchy of data types a public pushdown list for automatic recursive programming a rudimentary compiler for subroutine communication and bookkeeping and debugging aids
CACM	on the automatic simplification of computer programs presented in this paper is the problem of writing a program which would examine any other program and perform such simplifications on it as can be detected from the argument programs form alone without having any knowledge of what it is supposed to do
CACM	recorded magnetic tape for information interchange 200 cpi nrzi on the revised proposed american standard
CACM	graphic symbols for problem definition and analysis a standards working paper
CACM	american standard and ifip icc vocabularies compared the proposed american standard vocabulary of information processing and the ifip icc vocabulary of terms used in information processing are analyzed and compared
CACM	symbolic notations for statistical tables and an approach towards automatic system design the preparation of statistical tables is an important function of the data processing systems of some organizations and a symbolic notation for the description of tables has been shown to be a useful aid to documentation such a notation also provides the first step towards making automatic a tedious and time consuming part of system design and programming in many computer applications one notation is described and suggestions are made for the implementation of the larger goal
CACM	quikscript a simscript  like language for the g 20 quikscript is a simulation language based on simscript and programmed entirely in an algebraic language 20 gate the quikscript language its internal implementation and major differences between quikscript and simscript are presented this paper is not a programming guide to the language but rather an attempt to present its flavor a brief description of simscript is included as is a sufficient description of 20 gate to render this material understandable to the reader familiar with algebraic languages
CACM	the iteration element a recent addition to the mad language has made the iteration structure of the mad through statement corresponding to the algol for statement and the fortran do statement available within expressions
CACM	a method of data list processing with application to eeg analysis a set of subroutines is discussed which is designed to aid in the programming of computations on indexed lists of numbers using machine language or a symbolic assembly system the most commonly performed list operations are outlined and logically arranged into five groups as an example the computation of power spectral density from the autocovariance function is discussed for a class of eeg signals
CACM	dynamic variable formatting
CACM	debug an extension to current on line debugging techniques a method of on linr assembly language debugging which greatly simplifies several of the bookkeeping tasks characteristically associated with that process has been developed and implemented in a program for the univac m 460 computer at air force cambridge research laboratories with this program an online user may insert or delete in symbolic assembly language any number of lines at any point of his previously assembled program in core with the remainder of the program being relocated appropriately
CACM	an extended arithmetic package in many fields for example algebraic number theory arithmetic must be carried out to a degree of precision which exceeds the normal hardware capacity of most machines in such cases an extended arithmetic package provides a comprehensive and easy to use way of performing such arithmetic such a package was coded for the ibm 7090 in discussing the general problems associated with the design of an extended arithmetic package specific reference is made to this program
CACM	applications of binary numbers in computer routines a binary number can be thought of as an alternate form of expression for either a set of letters or a decimal number there are then three equivalent expressions easily translatable to one another each having different characteristics four examples are given in which the form of an expression is changed to an equivalent expression to save space or gain power
CACM	least squares analysis of resonance spectra on small computers the problem of analyzing data from a mossbauer effect experiment is discussed by using the cut step procedure for convergence and by imposing physical constraints on the functional form of the calculation it is possible to make the analysis on a small computer the analysis has been carried out on an ibm 1410 computer with a 40 000 bcd core memory
CACM	modeling and simulation of digital networks the simulation of digital networks on a digital computer provides the engineer with an effective means of analyzing time quantized logical behavior the digital network is modeled as a set of time dependent or time independent boolean transformations each transformation describing the input output relationship of a model element comprising the network mode the simplicity of utilizing the fortran iv programming system as a digital network simulator is discussed an illustrated this simplicity is derived from a common modeling technique applicable to combinational and sequential digital networks and a systematic programming approach
CACM	procedure oriented language statements to facilitate parallel processing two statements are suggested which allow a programmer writing in a procedure oriented language to indicate sections of program which are to be executed in parallel the statements are do together and hold these serve partly as brackets in establishing a range of parallel operation and partly to define each parallel path within this range do togethers may be nested the statements should be particularly effective for use with computing devices capable of attaining some degree of compute compute overlap
CACM	metalanguage and syntax specification two metalanguages are described one sufficient for the table specification of the algol syntax the other with additional metaoperators adequate and used for the formal table description of basic fortran
CACM	blnsys a 1401 operating system with braille capabilities blnsys is an operating system designed for a 4k 1401 with common optional features and two attached tape drives printed output of this system or of executing programs may be in either english or braille even though this system was written for a small machine with minimal peripheral equipment jobs may be batched so that card handling and lost processing time is at a minimum this system will perform any or all of the following users specified functions assemble sps source decks post list produce condensed or uncondensed object decks execute users program list card input to a program list punched output provide a storage dump execute a program submitted for execution as an uncondensed object deck under debugging trace control card to braille conversion brailled listings of 7040 ibsys batch output and update or duplicate the system tape itself input ouput subroutines are also included in the system
CACM	on the relative efficiencies of context free grammar recognizers a number of diverse recognition procedures that have been proposed for parsing sentences with respect to a context free grammar are described in this paper by means of a common device each procedure is defined by giving an algorithm for obtaining a nondeterministic turing machine recognizer that is equivalent to a given context free grammar the formalization of the turing machine has been chosen to make possible particularly simple description of the parsing procedures considered an attempt has been made to compare recognition efficiencies for the procedures defined for a few simple grammars and sentences a formal comparison has been made empirical comparison of the recognition of more realistic programming languages such as lisp and algol has been made by means of a program which simulates the turing machine on the univac m 460 computer several algorithms for producing grammars equivalent to a given context free grammar have been considered and the increase in recognition efficiency they afford has been empirically investigated
CACM	considerations relating to purpose of fortran standardization appendixes to asa fortran standard
CACM	performance of systems used for data transmission transfer rate of information bits  an asa tutorial standard information thruput as a characteristic of systems performance is discussed this discussion includes the pertinent aspects of information transfer of determination of transfer rate of information bits trib of residual errors and of standard measurement conditions the paper also presents an orderly arrangement of characteristics and parameters that affect information thruput and some examples on procedures for determining a thruput rate in terms of trib it concludes that a performance characteristic involving information rate can best be expressed as the trib in conjunction with the residual error rate
CACM	logarithm of a complex number algorithm 243 b3
CACM	computation of fourier coefficients algorithm c6
CACM	on algol education automatic grading programs two algol grader programs are presented for the computer evaluation of student algol programs one is for a beginners program it furnishes random data and checks answers the other provides a searching test of the reliability and efficiency of an integration procedure there is a statement of the essential properties of a computer system in order that grader programs can be effectively used
CACM	secondary key retrieval using an ibm 7090 1301 system the secondary key retrieval method involves the preparation of secondary storage lists from primary data records search requests are satisfied by logical operations on appropriate lists producing a complete set of addresses of primary records relevant to the request experimental results are presented and a comparative analysis is given
CACM	expanding the editing function in language data processing in automatic abstracting citation indexing mechanical translation and other such procedures editing is required whenever the automatic method leaves something to be desired this paper discusses the economy of editing as a function of the amount of condensation of text in language processing operations and then contends that editing can be regarded as an opportunity rather than as an unwelcome necessity heavy editing which goes beyond mere correction and improvement of computer output is exemplified by the use of a concordance in preparing a survey article or lecture other opportunities for heavy editing are described chief among them being interpretation and expansion of computer output in such processes as factor analysis applications are described such processes as factor analysis applications are described such as the quick unbiased evaluation of a large volume of incoming mail or telegrams yielding summary reports not possible for either humans or computers to produce alone
CACM	remark on romberg quadrature a modified form of romberg quadrature is described which is less sensitive to the accumulation of rounding errors than the customary one
CACM	on the numerical solution of an n point boundary value problem for linear ordinary differential equations a method for the numerical solution of then point boundary value problem for homogeneous linear ordinary differential equations is developed the method requires two runge kutta integrations over the interval under consideration and the solution of a linear system of equations with n 1 unknowns
CACM	code structures for protection and manipulation of variable length items corrigendum
CACM	still another use for fortran ii chaining
CACM	the use of cobol subroutines in fortran main programs
CACM	wengerts numerical method for partial derivatives orbit determination and quasilinearization in a recent article in the communications of the acm r wengert suggested a technique for machine evaluation of the partial derivatives of a function given in analytical form in solving non linear boundary value problems using quasilinearization many partial derivatives must be formed analytically and then evaluated numerically wengerts method appears very attractive from the programming viewpoint equations which might not otherwise be undertaken
CACM	use of a conditional base number system for encoding sequences of correlated characters a procedure is described for the relatively efficient encoding of sequences of characters which have predecessor successor selection rules the procedure is shown to assign a unique integer to each sequence and to generate a reasonably compact set of values
CACM	numerical integration of a differential difference equation with a decreasing time lag systems in which variable time lags are present are of common occurrence in biology variable flow rates are a common cause of these variable lags at present no extensive body of knowledge exists concerning the effects which these variable lags can cause shown here is a method of reducing some differential difference equations to ordinary differential equations which can then be studied numerically with ease subsequent study will deal with situations in which multiple lags and lags dependent on the solution itself are present
CACM	data input by question and answer a data input scheme for a time sharing computer is described in this paper instead of using format statements to determine the input the computer asks the user for the required values one at a time the computer converses with the user during the input process checks for errors provides standard data and allows editing of values input
CACM	the use of fortran in subroutines with cobol main programs by using the proper cobol coding techniques and accounting for differences in storage allocation and library routines between the two languages it is possible to write fortran iv subroutines that may be called from cobol main programs such a technique enables the programmer to take advantage of the most useful properties of each language while minimizing their respective disadvantages
CACM	matrix inversion algorithm 231 f1
CACM	bessel function for a set of integer orders
CACM	eigenvalues and eigenvectors of a real symmetric matrix by the qr method algorithm 254 f2
CACM	eigenvalues of a real symmetric matrix by the qr method algorithm 253 f2
CACM	vector coupling or clebsch gordan coefficients algorithm 252 z
CACM	clp the cornell list processor presented in this paper are the highlights of clp a teaching language which has been employed at cornell university and was constructed to serve as a means of introducing simulation and other list processing concepts the various advantages of clp are discussed and examples are given
CACM	proposed revised american standard code for information interchange
CACM	transparent mode control procedures for data communication using the american standard code for information interchange  a tutorial this paper gives the considerations of task group x3 3 4 in the area of transparent mode data communication control philosophy the appearance of this paper was forecast underthe name of second level control in the earlier tutorial paper control procedures for data communications task group document x3 3 4 44 dated may 1964 the present paper elaborates upon solutions to the problems of transparency to the basic ascii communication control characters as outlined in the previous paper mentioned above moreover it goes on to cover the additional control problems of handling material such as off line encrypted data or non ascii codes by means of systems providing complete character transparency it does not cover concepts of transparency in which the normal character structure or modulation rate of a system may be abandoned in conjunction with the earlier tutorial paper this paper is expected to lead to a proposal for stand ardizationof data communication control procedures using the american stand ard code for information interchange
CACM	tabular input of data
CACM	on a divide and correct method for variable precision division described in this paper is a divide and correct method for variable precision division in digital computers unlike the earlier methods of stein and pope the present method uses a suitably rounded form of the normalized divisor for getting an estimate of the quotient characters this results in a correction of at most plus or minus one to the estimate to obtain the exact quotient character it is believed that this method will be widely applicable for division operations in variable word length character oriented machines
CACM	method is randomness certain nonrandom properties of a commonly used random number generator are described and analyzed
CACM	note on triple precision floating point arithmetic with 132 bit numbers in a recent paper gregory and raney described a technique for double precision floating point arithmetic a similar technique can be developed for triple precision floating point arithmetic and it is the purpose of this note to describe this technique only the multiplication and the division algorithms are described since the addition subtraction algorithm can be obtained by a trivial modification of the algorithm in gregorys and raneys paper
CACM	pert time calculations without topological ordering a simplified technique is presented for pert time calculations without topological ordering each event is assigned a unique memory location an activity is represented by a link a link is defined as a memory location containing the address of another memory location the time information for an activity is carried with its link for a typical net the majority of activities can be described by one 36 bit cell each the remainder use two 36 bit cells each the links are unidirectional forward during the t e calculation expected completion time for an activity backward during the t l calculation time latest allowable for completion of an activity the calculations progress through the net topologically even though the net is not represented topologically in core
CACM	ative algorithm 205 e4
CACM	steep1 algorithm 203 e4
CACM	adaptive numerical integration by simpsons rule algorithm 145 d1
CACM	solutions of the diophantine equation algorithm 139 a1
CACM	function minimization algorithm 251 e4
CACM	on algol i o conventions
CACM	parallel signaling speeds for data transmission proposed american stand ard
CACM	a correspondence between algol 60 and churchs lambda notation part ii
CACM	a rapid turnaround multi programming system in this paper basic features system characteristics and the control algorithm for a multi programming system with rapid turnaround time are described
CACM	the internal structure of the fortran cep translator the fortran cep translator converts a source program written in the fortran cep language into an object program written in the language of the cep computer in this paper after an outline of the cep computer the internal structure of the translator is described emphasis is on the compilation of expressions of input output lists and of subscripted variables
CACM	a class of unambiguous computer languages discussed in this paper is the concept of a fully nested computer language which may be one means of designing computer languages which would be completely free of ambiguities several suggestions are also given here for the redefinition of algol as a fully nested language
CACM	a lightpen controlled program for on line data analysis this paper describes a technique designed to ease the use of a data processing system by a person in particular a scientist who is intimately and primarily concerned with interpreting the significance of data handled by the system since such a person is often unable to spend the time necessary to master a programming language it is essential that he be aided in composing commands to the computer in the system described the user is not required to learn or remember the vocabulary of the language because the vocabulary is displayed before him on menus by means of a computer drive scope he selects the various vocabulary elements required by pointing with the light pen by use of a small unordered set of rewriting rules applied as a result of light pen selections the user generates only syntactically correct commands to the system he does not have to learn or remember the grammar the program restricts the user severely in the particular language he can use but the method for communicating with the program makes these restrictions seem quite natural and unconstraining the program has been used successfully for over ten months
CACM	a mathematical model for mechanical part description the flexibility of a mathematical model takes advantage of the common information requirements of computer aided engineering drawing numerical control tape generation and physical characteristic computation by judicious control of man machine communication requirements improved results over conventional engineering design processes are possible an english like input language tailored for use by draftsmen and designers will describe the part and specify the output desired one approach to the mathematical model consists of a group of surface defining quadric equations which are created by a system of modular subprogram other subprograms will convert the mathematical model into instructions for driving automatic drafting machines and numerical controlled machine tools physical part characteristics such as center of gravity can be computed by subprograms and used in dynamic analysis work the proposed overall system is presented and experiments and demonstrations are discussed
CACM	a computer user oriented system a computer language system has been developed which makes possible fast preparation of management reports regardless of computational complexity or format variety costs are sufficiently low so that individually tailored reports can be prepared for every manager the system requires initial preparation of large data banks containing data in elementary form use of two special languages extract and matran permits selective extraction of any data subset efficient processing through any computational sequence and flexible presentation of results in either tabular or graphical form matrix algebra is used as a fundamental vehicle for accomplishing both manipulation and computation
CACM	a rapid braille transliteration technique for certain ibm machines
CACM	efficient autocorrelation
CACM	recursion and iteration
CACM	construction of nonlinear programming test problems
CACM	the organization of symbol tables an efficient symbol table organization is an important feature in the design of any compiler during the construction of the virginia algol 60 compiler for the burroughs b205 the primary consideration in the symbol table design was that the recognition of identifiers and reserved words should be as rapid as possible the general features of the technique are described
CACM	automation of the radioisotope accountability system the radioisotope service of the veterans administration hospital omaha nebraska used a manual system of radioisotope accountability for three years the procedure which was satisfactory but time consuming was converted from manual to a fully automated computer system in january 1963 the program for purchased radioisotopes is written in format fortran for the ibm 1620 computer a second program for maintaining accountability for reactor created radioisotopes is written in the forcom programming language a minimum amount of bookkeeping is required by the reactor operating staff the united states atomic energy commission regulations specify that records be kept this system provides detailed records for each container of radioactive material purchased and or created in the triga reactor indicating the amounts received used and or transferred to the health physicist for disposal consolidated records contain total amounts received used and or disposed of for any specified period of time purchased radioisotopes are reported in millicuries reactor created radioisotopes in microcuries
CACM	bessel functions of the first kind algorithm 236 s17
CACM	poisson charlier polynomials algorithm 234 s23
CACM	arccossin algorithm 206 b1
CACM	crout with equilibration and iteration algorithm 135 f4
CACM	inverse permutation algorithm 250 g6
CACM	outreal n algorithm i5
CACM	netflow algorithm 248 h
CACM	a correspondence between algol 60 and churchs lambda notation part i this paper describes how some of the semantics of algol 60 can be formalized by establishing a correspondence between expressions of algol 60 and expressions in a modified form of churchs l notation first a model for computer languages and compute behavior is described based on the notions of functional application and functional abstraction but also having analogues for imperative language features then this model is used as an abstract object language into which algol 60 is mapped many of algol 60s features emerge as particular arrangements of a small number of structural rules suggesting new classifications and generalizations the correspondence is first described informally mainly by illustrations the second part of the paper gives a formal description i e an abstract compiler into the abstract objct language this is itself presented in a purely functional notation that is one using only application and abstraction
CACM	answering english questions by computer a survey fifteen experimental english language question answering systems which are programmed and operating are described and reviewed the systems range from a conversation machine to programs which make sentences about pictures and systems which translate from english into logical calculi systems are classified as list structured data based graphic data based text based and inferential principles and methods of operations are detailed and discussed it is concluded that the data base question answer has passed from initial research into the early developmental phase the most difficult and important research questions for the advancement of general purpose language processors are seen to be concerned with measuring dealing with ambiguities translating into formal languages and searching large tree structures
CACM	remote on line real time computer diagnosis of the clinical electrocardiogram presented in this paper is a brief report on the hardware software system configuration and function of a system for the remote online real time digital computer diagnosis of clinical electrocardiograms it seems likely that efforts of this sort will lead to a satisfactory solution to the problem of the automatic diagnosis of electrocardiograms current attempts by the authors to extend the diagnostic capabilities of the present system are particularly concerned with increasing the fidelity of the adaptive matched filters the development of three dimensional pattern analysis the analysis of parallel electrocardiographer computer diagnostic interaction and a study of the possibility of introducing major tree like branching decisions early in the diagnostic process
CACM	boundary networks a feasible computer procedure is described for determining the total or partial inclusion of arbitrarily given points and lines with respect to a set of general polygonal domains which partition a plane bounded region a scheme for the computer representation of the boundaries of the domains and an algorithm based on this scheme for evaluating the inclusion relations are specified in detail the method employs several levels of selection criteria for the purpose of reducing the number of accesses to auxiliary storage devices and the amount of boundary data for which processing is required
CACM	use of decision tables in computer programming a decision table is a tabular form for displaying decision logic decision tables have many inherent advantages the technique to be illustrated puts these advantages to use in that it enables one to program directly from a decision table the technique is based on the creation of a binary image of a limited entry decision table in computer memory a binary image of a given set of input conditions can also be created this data image is used to scan the decision table image to arrive at the proper course of action there are several advantages gained from the programming point view 1 amount of computer memory used is drastically reduced 2 programming is simplified and 3 documentation is brief and clear
CACM	further remarks on reducing truncation errors
CACM	simulation of boolean functions in a decimal computer
CACM	automated plotting flow charts on a small computer
CACM	code structures for protection and manipulation of variable length items when items are made up of a variable number of characters each containing the same number of bits certain control information partition symbols is inserted to mark their separations since errors in identification of these control characters can lead to serious trouble methods of protecting these symbols are indicated a 6 bit code assignment of alphanumeric characters for fixed word length computers is given and its suitability for error detection and variable length item manipulation is shown also indicated is its flexibility during certain arithmetic operations
CACM	subroutine assembly a description is given of an assembly system which requires only one pass and does not maintain a table of information about the subroutine library
CACM	reducing truncation errors using cascading accumulators when accumulating a large number of quantities as in numerical integration the sum itself may become much larger than the individual addends this results in truncation error much of this error can be eliminated using cascading accumulators as noted in a recent article by wolfe a simpler and slightly more flexible algorithm is presented which deals also with the case of negative addends
CACM	mechanization of tedious algebra the newcomb operators of planetary theory a computer program has been written to generate tables of formulas for the newcomb operators of planetary theory the newcomb operators are expressed as polynomials in two variables one of which stands for a simple differential operator and the other for an arbitrary integer the polynomials are generated by a recurrence scheme the program is coded in fortran using simple array manipulation techniques to perform the algebraic operations formulas for over 100 newcomb operators have been produced by the program and typeset photographically on an s 560 photon system
CACM	character set for optical character recognition proposed american stand ard
CACM	npl highlights of a new programming language
CACM	euler a generalization of algol and its formal definition
CACM	additional comments on a problem in concurrent progamming control
CACM	a contribution to the development of algol
CACM	multiplexing of slow peripherals the philosophy of a monitor which allows slow output devices to be multiplexed is presented
CACM	levels of computer systems in building current computer systems we tend to break them down into levels of control command and communication in using the system we break our problems down correspondingly the continued use of such a structure raises questions about its effects on the usefulness of future systems particularly with regard to such trends as time sharing parallel programming and eventually systems which learn in this essay some of these questions are posed and the general attitude we must take in pursuing the problem further is discussed
CACM	transportation problem algorithms 293 h
CACM	havie integrator algorithm 257 d1
CACM	statistical computations based upon algebraically specified models based upon a machine readable statistical model and related symbolic specifications an efficient method of performing calculations for statistical models of a balanced complete nature is presented fixes mixed and random analysis of variance models are considered a procedure for obtaining variance components and calculated f statistics for the model terms is included
CACM	tensor calculations on the computer a formac program has been written which is capable of calculating various quantities of interest in tensor calculus using this code christoffel symbols have been calculated for 12 basic orthogonal coordinate systems
CACM	on the application of the process of equalization of maxima to obtain rational approximation to certain modified bessel functions the second remes algorithm as originally established for polynomials may converge or not when the approximating functions are rational however the few results known in this domain show how efficient the algorithm can be to obtain approximations with a small error much more than in the polynomial case in which the best approximation can be very nearly approached directly by a series development the aim of this paper is to investigate the limitations of the applicability of certain extensions of the algorithm to the case where the approximations are rational as well as to present some numerical results
CACM	general time varying systems error sensitivities program the evaluation by the propagation of variance technique of the sensitivity of time varying systems to initial condition and parameter errors involves the determination of several system dependent partial derivative matrices this requirement has led to separate programs for each system under investigation a new program through utilization of the wengert differentiation technique automatically determines the required matrices from specific system equations supplied in subroutine form at execution time eliminating the need for individualized programs and presaging the further development of extremely general computer programs
CACM	flowtrace a computer program for flowcharting programs the flowtrace system produces flowcharts of programs written in almost any programming language one most describe the syntax of the control statements in his language for this purpose a metalanguage is available the resultant object deck is used to flowchart any programs in the language described several examples of fap and snobol flowcharts are given however it is not necessary to confine ones scope to existing languages one may define his own language in any well structured manner this feature is particularly useful when it is desirable to chart only comments within a program such an approach permits the documentation of descriptive remarks and avoids the inclusion of coding details
CACM	computing capabilities at western european universities this report on the authors trip to universities in western europe in the summer of 1966 gives brief descriptions of computing activities at each institution visited present equipment capabilities vary from moderate to large scale however many institutions plan to acquire complex time shared systems in the near future in the authors opinion the state of the art lags behind that on this continent this lag is attributed to four principal factors a the handicapping organization of academic procedures b the university government financial relationship c the subordinated organization of the computing facility d the paucity of professional interchange of knowledge the effects of these constraints are explicated
CACM	the augmented predictive analyzer for context free languages its relative efficiency it has been proven by greibach that for a given context free grammar g a standard form grammar gs can be constructed which generates the same languages as is generated by g and whose rules are all of the form z    cy 1 y m m o where z and y i are intermediate symbols and c a terminal symbol since the predictive analyzer at harvard uses a standard form grammar it can accept the language of any context free grammar g given an equivalent standard form grammar gs the structural descriptions sd gs x assigned to a given sentence x by the predictive analyzer however are usually different from the structural descriptions sd g x assigned to the same sentence by the original context free grammar g from which gs is derived in section 1 an algorithm originally due to abbott is described standard form grammar each of whose rules is in standard form supplemented by additional information describing its derivation from the original context free grammar a technique for performing the sd gs x to sd g x transformation effectively is also described in section 2 the augmented predictive analyzer as a parsing algorithm for arbitrary context free languages is compared with two other parsing algorithms a selective top to bottom algorithm similar to irons error correcting parse algorithm and an immediate constituent analyzer which is an extension of sakai cockes algorithm for normal grammars the comparison is based upon several criteria of efficiency covering core storage requirements complexities of the programs and processing time
CACM	automatic error bounds on real zeros of rational functions a procedure for implementing an interval arithmetic version of the newton raphson method is proposed the procedure require only a starting interval over which the zeros of a given rational function are to be located the method automatically provides bounds for roundoff error
CACM	automatic integration of a function with a parameter two efficient methods for automatic numerical integration are romberg integration and adaptive simpson integration for integrands of the form f x g x a where a is a parameter it is shown that rombergs method is more efficient a fortran program shows how to achieve this greater efficiency
CACM	techniques for automatic tolerance control in linear programming in this technical note the numerical steps for the simplex method of linear programming are reviewed and the tolerances needed in the numerical procedure are defined objective criteria are given for accomplishing the numerical steps of the method and the calculation of necessary tolerances
CACM	conversion of decision tables to computer programs by rule mark techniques the rule mask technique is one method of converting limited entry decision tables to computer programs recent discussion suggest that in many circumstances it is to be preferred to the technique of constructing networks or trees a drawback of the technique as hitherto presented is its liability to produce object programs of longer run time than necessary in this paper a modification of the technique is discussed which takes into account both rule frequencies and the relative times for evaluating conditions this can materially improve object program run time
CACM	regular coulomb wave functions algorithm 292
CACM	havie integrator algorithm 257 d1
CACM	examination scheduling algorithm 286 h
CACM	syntax macros and extended translation a translation approach is described which allows one to extended the syntax and semantics of a given high level base language by the use of a new formalism called a syntax macro syntax macros define string transformations based on syntactic elements of the base language two types of macros are discussed and examples are given of their use the conditional generation of macros based on options and alternatives recognized by the scan are also described
CACM	data filtering applied to information storage and retrieval applications manipulation of data strings is the most complex processing function in information storage and retrieval applications data string manipulation is discussed within the context of an interpretive processing environment controlled by the use of procedural directives the sequence of procedural directives is derived from a job assumed to be expressed in a user oriented source language each data string with the structured data environment data bank is explicitly or implicitly related to a format declaration residing in a format library the processing mechanics associated with data string manipulation is developed in accordance with a generalized data filtering concept this results in the implementation of a two part data filter module that satisfies internal processing functions by filtering data strings through format declarations associated with its input and output ports
CACM	description of systems used for data transmission an asa tutorial
CACM	rectangular holes in twelve row punched cards proposed american standard
CACM	code extension in ascii an asa tutorial the american standard code for information interchange ascii contains a number of control characters associated with the principle of code extension that is with the representation of information which cannot be directly represented by means of the characters in the code the manner of use of these characters has not previously been completely described this paper presents a set of mutually consistent philosophies regarding code extension applications and suggests a corollary set of doctrines for the application of the code extension characters distinctions are drawn between code extension and such other concepts as graphic substitution or syntactic representation which are often used to meet similar requirements also covered are certain topics which are not truly concerned with code extension but which are often linked with it in discussion on code applications the material in this paper is equally applicable in principle to the proposed iso international 7 bit code for information interchange
CACM	a general method of systematic interval computation for numerical integration of initial value problems a procedure is given for continuously computing and monitoring the step size to be used by a self starting p th order numerical integration method to solve an initial value problem the procedure uses an estimate of the truncation error to calculate the step size
CACM	mathematical experimentation in time lag modulation equations of the form du dt g u t u h t arise in a number of scientific contexts the authors point out some interesting properties of the solution u t  u t 1 k sin wt sin at these properties were obtained by means of numerical solution
CACM	eliminating monotonous mathematics with formac the formac formula manipulation compiler programming system provides a powerful tool for performing mathematical analysis it is an extension of fortran iv which permits the use of the computer to perform the tedious algebraic computations that arise in many different fields among the areas in which it has been successfully used are differentiation of complicated expressions expansion of truncated power series solution of simultaneous equations with literal coefficients nonlinear maximum likelihood estimation tensor analysis and generation of the coefficients of equations in keplerian motion these types of analysis which arose in the solution of specific practical problems in physics engineering astronomy statistics and astronautics are discussed in the paper in addition to its usage for specific problem solutions formac can also be used to automate the analysis phase in certain production programming several such applications are presented
CACM	computer simulation discussion of the technique and comparison of languages the purpose of this paper is to present a comparison of some computer simulation languages and of some of the involved in comparing software packages for digital computers are discussed in part i the issue is obvious users of digital computers must choose from available languages or write their own substantial costs can occur particularly in training implementation and computer time if an inappropriate language is chosen more and more computer simulation languages are being developed comparisons and evaluations of existing languages are useful for designers and implementers as well as users the second part is devoted to computer simulation and simulation languages the computational characteristics of simulation are discussed with special attention being paid to a distinction between continuous and discrete change models part iii presents a detailed comparison of six simulation languages and packages simscript clp csl gasp cpss and sol the characteristics of each are summarized in a series of tables the implications of this analysis for designers of languages for users and for implementers are developed the conclusion of the paper is that the packages now available for computer simulation offer features which none of the more general purpose packages do and that analysis of strengths and weaknesses of each suggests ways in which both current and future simulation languages and packages can be improved
CACM	character structure and character parity sense for parallel by bit data communication in ascii proposed american standard
CACM	systematic generation of hamiltonian circuits for a combinatorial matrix which may specify both directed and nondirected arcs the paper describes a computer program which generates systematically and exhaustively all the hamiltonian circuits specific application is made to the traveling salesman problem
CACM	half rotations in n dimensional euclidean space an iterative procedure is described for determining half rotations in n dimensional euclidean space the method is a variant of the cyclic jacobi procedure and utilizers elementary plane rotations to obtain the half rotation matrix numerical examples are given
CACM	linear equations exact solutions algorithm 290 f4
CACM	logarithm of gamma function algorithm 291 s14
CACM	direct search algorithm 178 e4
CACM	gamma function gamma function for range 1 to 2 reciprocal gamma function to real argument gamma function logarithm of gamma function algorithms 34 s14 54 s14 80 s14 221 s14 291 s14
CACM	evaluation of determinant determinant evaluation algorithms 41 f3 269 f3
CACM	function minimization algorithm 251 e4
CACM	modified graeffee method algorithm 256 c2
CACM	pseudo random numbers algorithm 266 g5
CACM	pseudo random numbers algorithm 266 g5
CACM	a final solution to the dangling else of algol 60 and related languages the dangling else problem consists of a class of potential ambiguities in algol like conditional statements whose basic form is if b1 then if b2 then s1 else s2 where b1 and b2 are boolean expressions and s1 and s2 are basic statements the difficulty lies in whether to attach the else to the first if or to the second one existing solutions to the problem are either ambiguous or unnecessarily restrictive let sand s1 be statements we define s to be closed if s else s1 is not a statement and to be open if s else s1 is a statement thus an unconditional statement is a closed statement open and closed conditional statements are defined by syntax equations in such a way as to preserve openness and closure in each case an else must always be preceded by a closed statement it is shown that the syntax equations are unambiguous and that may change in the statement types required within the syntax equations would lead to either ambiguity or unnecessary restriction
CACM	simula an algol based simulation language this paper is an introduction to simula a programming language designed to provide a systems analyst with unified concepts which facilitate the concise description of discrete event systems a system description also serves as a source language simulation program simula is an extension of algol 60 in which the most important new concepts is that of quasi parallel processing
CACM	impact of computers on the undergraduate mathematics curriculum the use of computers to permit the widespread application of mathematical ideas requiring computation in science and technology is extremely significant for the understanding of our current society student interest in this development is intense and if properly utilized should yield a much better understanding of mathematical concepts as well as the ideas of programming and logical structure which have been introduced into many fields by the use of computers the present paper suggests that that portion of the undergraduate mathematical curriculum which is preparation for the use of mathematics by persons who are not professional mathematicians be modified to include the extensions and clarifications which are possible because of computers an early introduction to programming is desirable to permit a continuing use of automatic computation to illustrate and clarify mathematical concepts following the calculus equation stage an intensive introduction to numerical analysis should be added to the current curriculum in addition to providing competence in the mostly used computing techniques it would permit a more sophisticated utilization of the advanced mathematical ideas associated with complex variables and transform theories
CACM	desired computer impact on undergraduate mathematics three matters relating to the theme of the symposium are discussed here the author examines some projections concerning the supply and demand for mathematicians in the united states through the mid 1970s comments briefly on some of the factors which may influence the professional activities of applied mathematicians over the next several years and discusses in broad terms how this information may relate to the undergraduate training of mathematicians
CACM	implications of the digital computer for education in the mathematical sciences the digital computer has profoundly altered the definition of what is interesting in mathematics the importance of applied logic in human affairs is changed by the existence of the logical engine the result is that one should no longer think in terms of a single discipline of mathematics but in terms of a complex of mathematical sciences
CACM	mathematics for undergraduate computer scientists the mathematical requirements for an undergraduate program in computer science are a subject of debate the association for computing machinerys curriculum committee however believes that these requirements are essentially the same as the mathematical content of physical sciences undergraduate programs the committee believes that these requirements should assure the student of a broad mathematical background and should enable him to take a wide variety of courses in other scientific disciplines the committees concern is to develop a solid scientific approach to computer science
CACM	computer technology in communist china 1956 1965 based on information from translations of communist chinese news items and periodical literature for the 1965 period computer technology in china is reviewed under the following headings 1 initial planning organization and educational aspects of computer technology and automation 2 machine development progress two major specific machines in 1958 59 with soviet aid a vacuum in 1960 64 due to the withdrawal of soviet aid then presumably all chinese made machines from 1965 to the present 3 computer applications 4 the trend of automation control of production processes rather than data processing and 5 the yun chou hsueh science of operation and programming campaign of 1958 60 during which an attempt was made to bring concepts such as linear programming to ordinary chinese workers and peasants communist china is adjudged to have a marginal computer capability with most of its machines probably being of a binary nature however a turning point may have been reached in mid 1965
CACM	symbolic factoring of polynomials in several variables an algorithm for finding the symbolic factors of a multi variate polynomial with integer coefficients is presented the algorithm is an extension of a technique used by kronecker in a proof that the prime factoring of any polynomial may be found in a finite number of steps the algorithm consists of factoring single variable instances of the given polynomial by kroneckers method and introducing the remaining variables by interpolation techniques for implementing the algorithm and several examples are discussed the algorithm promises sufficient power to be used efficiently in an online system for symbolic mathematics
CACM	solution of systems of polynomial equations by elimination the elimination procedure as described by williams has been coded in lisp and formac and used in solving systems of polynomial equations it is found that the method is very effective in the case of small systems where it yields all solutions without the need for initial estimates the method by itself appears in appropriate however in the solution of large systems of equation due to the explosive growth in the intermediate equations and the hazards which arise when the coefficients are truncated a comparison is made with difficulties found in other problems in non numerical mathematics such as symbolic integration and simplification
CACM	automast automatic mathematical analysis and symbolic translation a procedure for numerically solving systems of ordinary differential equation is shown to also generate symbolic solutions the procedure is based on a finite taylor series expansion that includes an estimate of the error in the final result a computer program is described that reads in a system of such equations and then generates the expansions for all of the dependent variables the expansions are determined symbolically hence any non numeric parameters in the original equations are carried automatically into the final expansions thus the exact influence of any parameters on the problem solution can be easily displayed
CACM	a programmers description of l 6 bell telephone laboratories low linked list language l 6 pronounced l six is a new programming language for list structure manipulations it contains many of the facilities which underlie such list processors as ipl lisp comit ad snobol but permits the user to get much closer to machine code in order to write faster running programs to use storage more efficiently and to build a wider variety of linked data structures
CACM	convert a programming language is described which is applicable to problems conveniently described by transformation rules by this is meant that patterns may be prescribed each being associated with a skeleton so that a series of such pairs may be searched until a pattern is found which matches an expression to be transformed the conditions for a match are governed by a code which also allows subexpressions to be identified and eventually substituted into the corresponding skeleton the primitive patterns and primitive skeletons are described as well as the principle which allow their elaboration in to more complicated patterns and skeletons the advantages of the language are that it allows one to apply transformation rules to lists and arrays as easily as strings that both patterns and skeletons may be defined recursively and that as a consequence programs may be stated quite concisely
CACM	computer experiments in finite algebra a medium scale programming system is written in mad and fap on the ibm 7094 to manipulate some of the objects of modern algebra finite groups maps and sets of maps subsets and sets of subsets constant integers and truth values designed to operate in a time sharing environment the system can serve as a teachers aid to the undergraduate student of modern algebra as well as for the working scientist or engineer wishing to familiarize himself with the subset
CACM	experience with formac algorithm design various facets of the design and implementation of mathematical expression manipulation algorithms are discussed concrete examples are provided by the formac expand and differentiation algorithms a basic formac utility routine and an experiment in the extraction of the skeletal structure of an expression one recurrent theme is the need to avoid excessive intermediate expression swell in order to minimize core storage requirements although many details from the formac implementation are presented an attempt is made to stress principles and ideas of general relevance in the design of algorithms for manipulating mathematical expressions
CACM	pm a system for polynomial manipulation pm is an ibm 7094 program system for formal manipulation of polynomials in any number of variables with integral coefficients unrestricted in size some of the formal operations which can be performed by the system are sums differences products quotients derivatives substitutions and greater common divisors pm is based on the refco iii list processing system which is described and compared with the lisp and slip systems the pm subroutines for arithmetic of large integers are described as constituting an independently useful subsystem pm is compared with the alpak system in several respects including the choice of canonical forms for polynomials a new algorithm for polynomial greatest common divisor calculation is mentioned and exaples are included to illustrate its superiority
CACM	computation of algebraic properties of elementary particle reactions using a digital computer a large number of calculations in high energy elementary particle physics involve the manipulation of complicated algebraic expressions containing both tensor and noncommutative matrix quantities many of these calculations take several months to complete although the operations involved follow straightforward rules in this paper a program is described which has been developed in lisp for solving such problems the manner in which these problems are encountered is outlined and their representation in the computer discussed at present about six months of human work takes less than fifteen minutes on an ibm 7090 limitations of the present system and future plans are also outlined
CACM	on the implementation of ambit a language for symbol manipulation a brief description is given of the implementation technique for the replacement rule of the ambit programming language the algorithm for the ambit scan and an example of its application are given the algorithm is applicable to other members of the family of string transformation languages of which ambit is a member and it provides a rationale for the design of the ambit language
CACM	survey of formula manipulation the field of formula manipulation is surveyed with particular attention to the specific capabilities of differentiation integration and the supporting capabilities of simplification displays and input output editing and precision arithmetic general systems both batch and online are described finally some programs to solve specific applications are discussed
CACM	proceedings of the acm symposium on symbolic and algebraic manipulation the acm symposium on symbolic and algebraic manipulation brought together over four hundred people interested in programming languages designed for manipulation of algebraic formulas and symbol strings in their applications and in algorithms for their implementation twenty eight papers were presented followed by a lively panel discussion of future directions evening meetings were arranged for several interest groups the conference was sponsored by the acm special interest committee on symbolic and algebraic manipulation the program committee consisted of chairman jean e sammet paul abrahams thomas e cheatham max goldstein and douglas mcllroy conference arrangements were made by lewis c clapp daniel bobrow and james h griesmer  robert w floyd editor
CACM	robot data screening a solution to multivariate type problems in the biological and social sciences a new approach is outlined toward the solution of the type of multivariate problem that is found usually in the biological and social sciences as well as in medicine this approach uses a logical rather than a statistical criterion by which variables are grouped into a deterministic model algorithm are developed by which some variables are kept on for further analysis while others are eliminated criteria for the acceptance of a variable as well as the termination of the searching process are derived from information theory
CACM	on top to bottom recognition and left recursion a procedure is given for obtaining structural descriptions in a context free grammar by performing the recognition according to a strongly equivalent left recursion freegrammar the effect of allowing null strings in the rewriting rules is discussed
CACM	free text inputs to utility routines through the use of some rather simple techniques it is frequently possible to produce a program which will accept free text inputs the techniques are discussed and related to a general tape manipulation routine
CACM	quasilinearization and the calculation of eigenvalues several eigenvalue problems for systems of ordinary differential equations are considered they are resolved computationally using the quasilinerization technique a quadratically convergent successive approximation scheme related to the newton raphson kantorovich method
CACM	partial step integration a partial step integration equation is derived for use with the adams or adams bashforth method of integration of differential equations this method of obtaining functional values at points intermediate to the integration points yields accuracy comparable to the integration and does not require storing of additional information as in interpolation methods
CACM	a method for finding the m smallest values of a monotonic function defined on ordered sets of positive integers the minimum value of a monotonic increasing function defined on a partially ordered set s is assumed on the set of minimal points of s this observation is used to devise an efficient method for finding the m smallest functional values of monotonic functions defined on ordered pairs of positive integers the method is easily extended to include monotonic functions defined on ordered n tuples included is a fortran program which was written to implement the procedure for a certain important case
CACM	computational aspects of multiple covariance analysis on a multifactor structure the computational procedure for the analysis of multiple covariance in statistics is discussed with reference to the analysis of variance a special operator calculus developed by hartly for programming analysis of variance for multifactor experiments is extended to cover the analysis of covariance this extension is accomplished by utilizing the connection between the analysis of covariance and the analysis of variance and by introducing a new operator the results are illustrated by a numerical example for analysis of covariance in which the basic computations are shown to be carried out by an analysis of variance program
CACM	matrix triangulation with integer arithmetic algorithm 287 f1
CACM	solution of simultaneous linear diophantine equations algorithm 288 f4
CACM	confidence interval for a ratio algorithm 289 g1
CACM	the eschenbach drum scheme the prime function of a drum operating in real time is to perform accesses quickly the usual means for increasing this capacity is to incorporate engineering or hardware improvements in this paper the problem is attacked not by changing the drum but rather by modifying the manner in which it operates at the outset a drum is given a functional definition then a simple design scheme eschenbach is introduced which enormously increases the rate of accessing for drums so defined this is shown to enable a system to perform a job by employing fewer or less expensive drums it is suggested that although the design scheme has a specific use the method underlying it has more general applicability the question of the efficacy of the drum scheme is then raised to deal with this a standard of efficiency is developed in light of realistic real time circumstances the drum scheme is then modelled in a manner which permits it to be analyzed as a problem in queueing theory thus one is enabled to ascertain whether the drum scheme is efficient enough for its application again whereas the analysis of the drum scheme has a specific use the methods underlying it have more general applicability
CACM	nebula a digital computer using a 20 mc glass delay line memory oregon state university has designed and constructed a medium speed serial digital computer using glass delay lines circulating at 22 mc as memory the design objectives as originally conceived in a special seminar were 1 to be a research project in computer design 2 to be usable as an educational machine and 3 to have easily modifiable hardware for basic research in computer systems design an unusual arrangement of information within the 22 mc memory allows a simple interface with the 340 kc arithmetic unit which results in an effective zero latency time and provides possibilities for an associative memory the arithmetic unit has a command structure similar to large parallel machines and uses flip flop arithmetic and control registers throughout all hardware development has been aimed toward the concept of easy modification elaborate console controls for effective man machine interaction and low cost
CACM	interarrival statistics for time sharing systems the optimization of time shared system performance requires the description of the stochastic processes governing the user inputs and the program activity this paper provides a statistical description of the user input process in the sdc arpa general purpose time sharing system tss the input process is assumed to be stationary and to be defined by the interarrival time distribution the data obtained appear to justify satisfactorily the common assumption that the interarrival times are serially independent the data do not appear to justify except as a very rough approximation the usual assumption off an exponential distribution for interarrival time a much more satisfactory approximation to the data can be obtained with a biphase or triphase hyperexponential distribution
CACM	comparison of several algorithms for computation of means standard deviations and correlation coefficients several algorithms for computation of basic statistics are compared by their performance on systematically generated test data the statistics calculated were the mean standard deviation and correlation coefficient for each statistic the algorithm included the usual computing formulas correction due to an accumulated error term and a recursive computation of the current value of the statistic the usual computing formulas were also evaluated in double precision large errors were noted for some calculation using the usual computing formulas the most reliable technique was correction of the initial estimate by use of an accumulated error term to eliminate the need for making two passes on the data it was suggested that the initial estimate of the mean be obtained from a subset of the data
CACM	the banking information system concept most large commercial banks have progressed to the point where their major accounting applications have been automated and more sophisticated usage of data processing equipment is being sought this coupled with the availability of equipment well suited to real time direct access processing has led to development within some banks of the central file of data base approach toward a banking information system the banking information system now serves the two fold purpose of providing real time responses to inquires about individual account stasus and providing more complex combinations of information for management use both kinds of processing draw upon a common store of data contained in the direct access central file this data base includes indexes which facilitate cross referencing of account information so that all relationships between bank and customer may be discerned in introducing the banking information system concept a gradual approach to account cross referencing and file conversion is most prudent generally this system must interface with other computer applications already existing within the bank
CACM	a vision of technology and education educational technology is currently quite fashionable here as in many other branches or aspects of technology changes possible in the next generation or two are now known as ideas discoveries or inventions the unknown is whether the potential will become the actual and if so on what time scale this ignorance stems largely from ignorance about the social response to potential technological change the object of this paper is to present a vision of potential educational technology and to raise questions about the modes of social response and adaptation likely to be evoked by such a vision
CACM	twelve row punched card code for information interchange proposed american standard
CACM	automatic derivation of microsentences the decomposition of long complex english sentences into shorter kernel like constituent sentences microsentences has often been suggested as an avenue toward conducting automatic retrieval of natural language messages to explore the prospects of such a step the authors attempted in 1963 to prepare a general program for deriving microsentences from longer sentences that had been syntactically analyzed by the harvard multipath analysis program the basic idea was to extract the subject verb and object if any of each clause and to reassemble these materials into a grammatical microsentence a program is described in this paper which was designed to operate on the tree structure output of the analyzer and the microsentences that were produced are exhibited the authors conclude that while microsentences of the quality achieved do not open up immediate prospects for improving the performance of automatic message retrieval systems they may have practical value in man machine systems using human monitors to select the preferred syntactic interpretation of a sentence
CACM	a fortran technique for simplifying input to report generators typical report generators allow the production of standard forms when tabulating a magnetic tape file the extraction of nonstandard sets of information with suitable annotation involves troublesome forms design a method of information extraction involving the calculation of suitable fortran format statements which combats this problem is described
CACM	economies of scale and the ibm system 360 cost functions among five system 360 models are analyzed through examinations of instruction times program kernels and a typical instruction mix comparisons are made between the data developed here and groschs law which seems to be applicable to much of the data sizable economies of scale are unquestionably present in computing equipment
CACM	examination scheduling algorithm 286 zh
CACM	chebyshev quadrature algorithm 279 d1
CACM	a new uniform pseudorandom number generator a new multiplicative congruential pseudorandom number generator is discussed in which the modulus is the largest prime within accumulator capacity and the multiplier is a primitive root of that prime this generator passes the usual statistical tests and in addition the least significant bits appear to be as random as the most significant bits a property which generators having modulus 2 k do not possess
CACM	a contribution to the development of algol a programming language similar in many respects to algol 60 but incorporating a large number of improvements based on six years experience with that language is described in detail part i consists of an introduction to the new language and a summary of the changes made to algol 60 together with a discussion of the motives behind there visions part ii is a rigorous definition of the proposed language part iii describes a set of proposed standard procedures to be used with the language including facilities for input output
CACM	eleven sixteenths inch perforated paper tape proposed american standard
CACM	a simple algorithm for computing the generalized inverse of a matrix the generalized inverse of a matrix is important in analysis because it provides an extension of the concept of an inverse which applies to all matrices it also has many applications in numerical analysis but it is not widely used because the existing algorithms are fairly complicated and require considerable storage space a simple extension has been found to the conventional orthogonalization method for inverting non singular matrices which gives the generalized inverse with little extra effort and with no additional storage requirements the algorithm gives the generalized inverse for any m by n matrix a including the special case when m n and a is non singular and the case when m n and rank a n in the first case the algorithm gives the ordinary inverse of a in the second case the algorithm yields the ordinary least squares transformation matrix inv aa a and has the advantage of avoiding the loss of significance which results in forming the product aa explicitly
CACM	automatic analysis of electronic digital circuits using list processing a mapping from black diagrams of digital circuits to list structures is described together with a list processing program written for the control data 3600 which uses this mapping to automatically carry out circuit analysis
CACM	flow diagrams turing machines and languages with only two formation rules in the first part of the paper flow diagrams are introduced to represent inter al mappings of a set into itself although not every diagram is decomposable into a finite number of given base diagrams this becomes true at a semantical level due to a suitable extension of the given set and of the basic mappings defined in it two normalization methods of flow diagrams are given the first has three base diagrams the second only two in the second part of the paper the second method is applied to the theory of turing machines with every turing machine provided with a two way half tape there is associated a similar machine doing essentially the same job but working on a tape obtained from the first one by interspersing alternate blank squares the new machine belongs to the family elsewhere introduced generated by composition and iteration from the two machines l and r that family is a proper subfamily of the whole family of turing machines
CACM	a simulation of hospital admission policy a study is described which simulates different admission policies of a large specialized hospital the objective is to determine better policies for stabilization of admission and census rates while maintaining a reasonably full hospital there types of policies were examined admission based on percentages of discharge rates discharge rates plus or minus a constant and fixed authorizations independent of discharge rates the last type policy produced more stable simulated results and when put into practice improvements were realized
CACM	simulation of radioisotope scans by computer in radioisotope scanning a field which is assuming increasing importance in medical diagnosis the scan is a two dimensional pattern made up of dots areas of increased source activity are represented on the scan by areas of increased dot density to study the output of scanners with various characteristics a program which simulates radioisotope scans has been written for a pdp 1 computer with auxiliary disk storage and cathode ray tube display past and present research using the output of the simulator has shown the flexibility of the system to be important the structure of this program can be useful in the simulation of the output of any quantum limited system
CACM	shock iii a computer system as an aid in the management of critically iii patients shock iii an online digital computer system to assist the physician nurse and paramedical personnel in monitoring and reporting on critically ill patients is described
CACM	matrix reduction using the hungarian method for the generation of school timetables the application of kuhns hungarian method to the problem of matrix reduction as needed in gotliebs method for timetable generation is described the method is suited to both hand and computer calculation devices to improve the efficiency of the basic algorithm are discussed
CACM	multiple precision floating point conversion from decimal to binary and vice versa decimal to binary and binary to decimal floating point conversion is often performed by using a table of the powers 10 i ia positive integer for converting from base 10 to base 2 and by using a table of the coefficient of a polynomial approximation of 10 x 0 x 1 for converting from base 2 to base 10 these tables occupy a large storage region in the case of a nonsingle precision conversion this paper shows that a single small table suffices for a floating point conversion from decimal to binary and vice versa in any useful precision
CACM	on a storage mapping function for data structures some basic facts about certain data structures are reviewed and an efficient algorithm is presented for constructing a storage mapping function for a structure from the structures definition
CACM	incorporation of nonstandard input output devices into fortran systems a fortran system may readily be modified to handle input output with nonstandard media on the same basis on which it handles the standard media this is done by providing a character handling subroutine suited to the nonstandard medium and arranged to be called by an otherwise unused output statement type or unit number this method was used to control output of alphanumeric information on a digital graph plotter
CACM	a note on linear programming algorithm design a combinatorial problem as linear programming models grow bigger and bigger in size much actual data that must be memorized is often put on magnetic tape or disk and consequently there is an improportionality fast rise in the consumption of computer time to cut down this expense an ever increasing effort is made to design more efficient algorithms this paper is meant to support the effort it is attempted to find some characteristics of the way a pivot column is found the number of repetitions of a certain transfer of data from tape to core memory is considered after some simplification the problem is restated in a general way the generating function of the probability distribution and the moment generating function of the number of repetitions is found asymptotic formulas are given for the moments using a result from a paper of s narumi 1 the results may be applied to write very efficient routines that search for an extreme value in a table formulas provide a means of calculating the computer timings in this case
CACM	a monte carlo algorithm for assigning students to classes a technique of random choice is illustrated by application to the problem of assigning students to a fixed schedule of courses using the technique it is possible to reduce or eliminate difficulties that result when a popular section is filled and closed before all students requesting and requiring it have been scheduled the effectiveness of automatic scheduling is retained without loss of the students privilege of picking favorite instructors
CACM	design of computer simulation experiments for industrial systems the aim of this paper is to provide background information on the existing literature on experimental design techniques which may be applicable to the design of computer simulation experiments for industrial systems although major emphasis is placed on analysis of variance techniques three other techniques of data analysis are considered multiple ranking procedures sequential sampling and spectral analysis the paper treats four specific experimental design problems and several techniques for solving them the four experimental design problems are 1 the problem of stochastic convergence 2 the problem of factor selection 3 the problem of motive and 4 the many response problem
CACM	interchange of two blocks of data algorithm 284 k2
CACM	the mutual primal dual method algorithm 285 h
CACM	a method for locating zeros of complex functions a method for computing the index or winding number is developed and applied to the problem of finding zeros of functions from the plane into the plane
CACM	mechanization of the curve fitting process datan a process for fitting a curve to approximate data and the problem it creates for the engineer programmer is defined an approach has also been defined and a system has been written for the sru 1107 to mechanize a major portion of this process the techniques developed to accomplish the mechanization are largely empirical and are dependent for their information only on the actual data points
CACM	starting approximations for square root calculation on ibm system 360 several starting approximations for square root calculation by newtons method are presented in a form to facilitate their use in ibm system 360 square root routines these approximations include several for the range 1 16 1 which is the interval of primary interest on ibm system 360
CACM	methods of numerical integration applied to a system having trivial function evaluations a study has been made to determine which methods of numerical integration require the least computation time for a given amount of truncation error when applied to a particular system of ordinary differential equations where function evaluations are relatively trivial recent methods due to butcher and gear are compared with classic runge kutta kutta nystrom and adams methods some of the newer one step methods due to butcher are found to be slightly superior but no one method is found to have any great advantage over the others in the application to this particular problem
CACM	recorded magnetic tape for information interchange 800 cpi nrzi proposed american standard
CACM	a method for finding the least squares estimate of the intersection point of two helices in space when the helical trajectories of two charged particles moving away from a common point in a magnetic field are reconstructed from measurements on the tracks the reconstructed tracks are perturbed by measurement and other errors and do not in general intersect a method is given for adjusting the reconstructed tracks in a least squares manner so that they do intersect
CACM	an algorithm for generating projective reduction formulas for matrix elements of many electron wavefunctions an algol procedure is given for automatically generating formulas for matrix elements arising in the variational solution of the schrodinger equation for many electron systems
CACM	use of the computer to teach introductory statistics it has always been obvious that the aid to calculation offered by the computer forces a change in the curricula of mathematics statistics physics engineering and other courses not so obvious are the many pedagogic aids the computer can offer in teaching the subject matter the possibilities of giving the student a better technical as well as conceptual understanding of statistics were explored for a number of years at the college of medicine of the university of cincinnati and are reported here
CACM	chebyshev quadrature algorithm 279 d1
CACM	abscissas and weights for gregory quadrature d1
CACM	abscissas and weights for romberg quadrature algorithm 281 d1
CACM	derivatives algorithm 282 s22
CACM	simultaneous displacement of polynomial roots if real and simple algorithm 283 c2
CACM	runge kutta integration algorithm 9 d2
CACM	kutta merson algorithm 218 d2
CACM	a nonrecursive method of syntax specification the use of the kleene regular expression notation for describing algebraic language syntax in particular of algol is described in this paper a fortran ii computer program for carrying out the elimination algorithm of gorn similar to gaussian elimination for linear systems of algebraic equations is described this was applied to numerous smaller languages including some sublanguage of algol a hand calculation result of the application of the algorithm to all of algol is given thus expressing the revised algol 1960 syntax in completely nonrecursive terms as far as its context free portion is concerned this description in many ways is far more intuitively understood than the previous recursive description it is suggested the paper also includes results of the machine program which does not include a simplification algorithm
CACM	a simple user oriented compiler source language for programming automatic test equipment for the nonprogrammer difficulty in using a language increases rapidly with the number of nonproblem oriented conventions a simple language even if inelegant which considers the users background as part of the problem may be more effective than a source language containing subtle and more powerful capabilities the language described in this paper is used to write computer programs which test electronic equipment because this testing process contains few complex ideas there is little need for the elegance and redundancy of a highly syntax oriented language a simple and direct language will suffice for the problem the eventual users of this language are military depot personnel who cannot he expected to have computer programming skill or significant programming training for this nonprogramming oriented user it was essential to create a language using familiar engineering statements programming oriented conventions would have unnecessarily complicated his task
CACM	trac a procedure describing language for the reactive typewriter a description of the trac text reckoning and compiling language and processing algorithm is given the trac language was developed as the basis of a software package for the reactive typewriter in the trac language one can write procedures for accepting naming and storing any character string from the typewriter for modifying any string in any way for treating any string at any time as an executable procedure or as a name or as text and for printing out any string the trac language is based upon an extension and generalization to character strings of the programming concept of the macro through the ability of trac to accept and store definitions of procedures the capabilities of the language can be indefinitely extended and can deal with character strings integers and boolean vector variables
CACM	storage and retrieval of aspects of meaning in directed graph structures an experimental system that uses lisp to make a conceptual dictionary is described the dictionary associates with each english word the syntactic information definitional material and references to the contexts in which it has been used to define other words such relations as class inclusion possession and active or passive actions are used as definitional material the resulting structure serves as a powerful vehicle for research on the logic of question answering examples of methods of inputting information and answering simple english questions are given an important conclusion is that although lisp and other list processing languages are ideally suited for producing complex associative structures they are inadequate vehicles for language processing on any large scale at east until they can use auxiliary memory as a continuous extension of core memory
CACM	data manipulation and programming problems in automatic information retrieval automatic information retrieval programs require the manipulation of a variety of different data structures including linear text sparse matrices and tree or list structures the main data manipulations to be performed in automatic information systems are first briefly reviewed a variety of data representations which have been used to describe structured information are then examined and the characteristics of various processing languages are outlined in the light of the procedures requiring implementation advantages of these programming languages for the retrieval application are examined and suggestions are made for the design of programming facilities to aid in information retrieval
CACM	online programming when the transition has been made from off line to online programming there are a number of changes in the working conditions noted these changes in the environment make necessary corresponding changes in the processes related to producing and checking out programs in the main it it not the programming language itself which must be changed to provide a facility for the online user it is the system surrounding the programming language in this paper the online environment and its effect on programming are discussed
CACM	requirements for real time languages real time languages have different requirements from other programming languages because of the special nature of their applications the environment in which their object programs are executed and the environment in which they may be compiled it may not be the language extensions that ultimately advance developments in the field progress may be made by attacking the special compiling and executing system problems that must be solved
CACM	evolution of the meta assembly program a generalized assembler called a meta assembler is described the meta assembler is defined and factors which contributed to its evolution are presented how a meta assembler is made to function as an assembly program is described finally the implication of meta assemblers on compiler design is discussed
CACM	discussion summary on operating systems
CACM	multilevel operating systems the basic software for all newer computers is built on the well established need for standard operating systems this implies that all applications no matter how large complex or time consuming must operate under or more precisely on top of the standard system large applications require supervisory monitors which handle problems similar to those of the operating systems but at a different level sometimes still a third or even a fourth such level is required or desirable this leads naturally to the concept of multilevel systems similar vertically but different horizontally proper division of responsibility between levels leads to greater efficiency and less logical complexity while actually enhancing capability
CACM	more on extensible machines one of the most salient characteristics of extensible machines em is the facility for providing system control over program to program and program to data linkage e g address connection it is the intent of this paper to expand and clarify the remarks concerning program to program and program to data linkage that were embodied in the authors previous paper on the em concepts and to finally trace the employment of linkage mechanisms through various levels of programming languages
CACM	an algol compiler construction and use in relation to an elaborate operating system an algol translator has been prepared and integrated into the ibsys operating system assembly and go features of ibsys permit immediate execution with optional listings decks and debugging information using the chain feature of ibsys links written in map or fortran as well as algol may be called by the algol main program in addition procedures coded in map may be included in any algol program although assembly plus loading time exceeds compilation time the total time is satisfactory and the user gets ease and facility which are fully compensating
CACM	program translation viewed as a general data processing problem efficiency dictates that the overall effectiveness of a compiler be increased by all means available for a compiler to have a substantial useful life it needs a clear logical structure reliability and sound data processing techniques a compiler must be based on fixed conventions to preserve efficiency and reliability empty options and default conventions violate this dictum use of structure to associate various parts of a program and economy of features promote clarity and reliability
CACM	discussion summary on graphical languages
CACM	a graphical servicesystem with variable syntax man machine interaction in many fields of endeavor should be greatly facilitated in the near future through the use of interactive graphical languages to provide a variety of display scope communication procedures a graphic service system which functions as a generalized graphical language translator is being developed to aid the definition as well as the use of new graphical languages
CACM	syntax directed interpretation of classes of pictures a descriptive scheme for classes of pictures based on labeling techniques using parallel processing algorithms was proposed by the author some years ago since then much work has been done in applying this to bubble chamber pictures the parallel processing simulator originally written for an ibm 7094 system has now been rewritten for a cdc 3600 system this paper descriptive models by considering their specific application to bubble chamber pictures how the description generated in this phase can be embedded in a larger conversation program is explained by means of a certain specific example that has been worked out a partial generative grammar for handwritten english letters is given as are also a few computer generated outputs using this grammar and the parallel processing simulator mentioned earlier
CACM	the next 700 programming languages a family of unimplemented computing languages is described that is intended to span differences of application area by a unified framework this framework dictates the rules about the uses of user coined names and the conventions about characterizing functional relationships within this framework the design of a specific language splits into two independent parts one is the choice of written appearances of programs or more generally their physical representation the other is the choice of the abstract entities such as numbers character strings lists of them functional relations among them that can be referred to in the language the system is biased towards expressions rather than statements it includes a nonprocedural purely functional subsystem that aims to expand the class of users needs that can be met by a single print instruction without sacrificing the important properties that make conventional right hand side expressions easy to construct and understand
CACM	the structure of programming languages the following are identified as major components of every programming language 1 the elementary program statement 2 mechanisms for linking elementary statements together 3 the means by which a program can obtain data inputs several alternative forms of each of these components are described compared and evaluated many examples frequently from list processing languages illustrate the forms described elementary program statements usually take the form of commands requirements or implicit specifications a command is an imperative statement that commands the action to be taken a requirement describes the effect to be achieved without saying anything about the actions to be taken an implicit specification is similar to a requirement but the programmer must understand what actions will be taken to achieve the desired effect subroutines may be entered explicitly by execute call or by function composition explicitly called subroutines generally require special linkage conventions an execute subroutine call is syntactically indistinguishable from a basic instruction of the programming language function composition is a convenient alternative to the explicit call the three principal ways of getting inputs for routines are 1 by referring to the data itself 2 by referring to the data by a name and 3 by referring to it implicitly by means of variables or functions names are useful entry points into permanent data structures but can be error causing distractions in other contexts the author discusses advantages disadvantages and factors influencing the choice of a form of component for a language he concludes by suggesting the evolution of programming languages toward one which will permit all the most convenient ways of structuring programs organizing systems and referencing data
CACM	programming semantics for multiprogrammed computations the semantics are defined for a number of meta instructions which perform operation essential to the writing of programs in multiprogrammed computer systems these meta instructions relate to parallel processing protection of separate computations program debugging and the sharing among users of memory segments and other computing objects the names of which are hierarchically structured the language sophistication contemplated is midway between an assembly language and an advanced algebraic language
CACM	description of a high capacity fast turnaround university computing center the operating system for the univac 1107 at case institute is reviewed the system is of interest because of the low turnaround times achieved the high throughput achieved and the lack of an operating staff turnaround times below 5 minutes and job volume above 75 000 per quarter year one reported
CACM	the stability of the fourth order runge kutta method for the solution of systems of differential equations the problem of the region of stability of the fourth order runge kutta method for the solution of systems of differential equations is studied this region can be characterized by means of linear transformation but can not be given in a closed form in the paper this region is determined by the electronic digital computer z22
CACM	tests of probabilistic models for propagation of roundoff errors in any prolonged computation it is generally assumed that the accumulated effect of roundoff errors is in some sense statistical the purpose of this paper is to give precise descriptions of certain probabilistic models for roundoff error and then to describe a series of experiments for testing the validity of these models it is concluded that the models are in general very good discrepancies are both rare and mild the test techniques can also be used to experiment with various types of special arithmetic
CACM	dribble posting a master file many business applications employ sequential magnetic tape rather than random access storage techniques to process a very small number of transactions against a voluminous master file in such situations it may prove economical to avoid creating a new master file during each updating run by producing instead a dribble ledger containing only those master file accounts which have experienced activity
CACM	control procedures for data communication an asa progress report sectional committee x 3 of the american standards association has charged one of its task groups x3 3 4 with the responsibility to define and specify functional control requirements and characteristics governing the operation of digital data generating and receiving systems interconnected by communication system this effort is primarily directed toward systems employing the american standard code for information interchange ascii this paper represents a progress report on the work of this group toward a proposal for national and international standardization in the field of control procedures it describes both the old and new work of the task group the new work is presented in detail while the work that has been presented in earlier papers control procedures for data communication task group document x3 3 4 44 may 1964 transparent mode control procedures for data communication task group document x3 3 4 58 december 1964 comm acm 8 apr 1965 203 206 control procedures for data communications task group document x3 3 4 60 march 1965 is retained here in summary form many of the concepts and principles described herein have been submitted to the international organization for standardization via earlier papers and are now embodied in working papers of that organization
CACM	euler a generalization of algol and its formal definition part ii
CACM	exponential curve fit algorithm 275 e2
CACM	constrained exponential curve fit algorithm 276 e2
CACM	computation of chebyshev series coefficients algorithm 277 c6
CACM	graph plotter algorithm 278 j6
CACM	bugsys a programming system for picture processing not for debugging bugsys is a picture processing and measuring system that depends upon a pictorial input to the computers memory bugsys can be used for many types of applications in particular the authors have used the system for the analysis of linear graphs the main concept of the system is the use of a collection of programmable pointers which are visualized as a family of bugs
CACM	a comparison of the fortran language implementation for several computers a feature by feature comparison is made of five different implementations of fortran iv representing three different manufacturers a table is constructed showing where possible the use of each feature in each implementation only those items which are different from or have been added to fortran ii are shown
CACM	a language for describing the functions of synchronous systems before the design of a system is started the exact function desired of it should be specified it is suggested that a computer oriented language be used for this purpose the inadequacies of the standard programming languages for the description of systems are discussed and a dialect of algol which is suitable for describing synchronous systems is introduced these descriptions can be used for simulation and automatic design of the system described in addition to communicating system specifications
CACM	the structure of programming languages in this paper the major components of every programming language are identified as 1 the elementary program statement 2 mechanisms for linking elementary statements together 3 the means by which a program can obtain data inputs several alternative forms of each of these components are also described compared and evaluated many examples frequently from list processing languages illustrate the forms described the advantages disadvantages and factors influencing the choice of a form of component for a language are discussed and the paper concludes with the suggestion that programming languages evolve toward one which will permit all the most convenient ways of structuring programs organizing systems and referencing data
CACM	a reprogramming machine in this paper a description is given of a model programming system which is directed by a programming language and has a library for storing the users items rules are given for transforming programs written in the language and for rearranging the items in the library so that they share their common parts some speculations are made about how the mechanical detection of common parts or patterns of library items could help a user to solve his problems and about the relationships between the behavior of the reprogramming machine and human intelligent behavior
CACM	eliza a computer program for the study ofnatural language communication between man and machine eliza is a program operating within the mac time sharing system at mit which makes certain kinds of natural language conversation between man and computer possible input sentences are analyzed on the basis of decomposition rules which are triggered by key words appearing in the input text responses are generated by reassembly rules associated with selected decomposition rules the fundamental technical problems with which eliza is concerned are 1 the identification of key words 2 the discovery of minimal context 3 the choice of appropriate transformations 4 generation of responses in the absence of key words and 5 the provision of an editing capability for eliza scripts a discussion of some psychological issues relevant to the eliza approach as well as of future developments concludes the paper
CACM	programming decision tables in fortran cobol or algol a simple broad based approach for programming decision tables in fortran or cobol is developed and presented with inputs in standard form as defined in the paper the programming of any decision table can be done with one or two fortran statements or with two cobol statements if the compute verb is available in the cobol processor it is shown that the method is applicable even when there are more than two mutually exclusive states of one two or more table conditions it is further shown that multi state conditions in decision tables can often simplify the programming the method outlined has the further advantage that all possible combinations of conditions are considered it is shown that the suggested procedure is easily implemented in algol
CACM	data documentation and decision tables in business data processing systems it is necessary to be able to define and document data files programs and decision rules in a way that adequately represents both 1 their changing information content and 2 their continuous interaction tabular description makes this possible being notably objective through and economical in cost and time when systems must be analyzed and programs prepared or modified to show how quickly tabular techniques make an unfamiliar system manageable a detailed example and a self test are provided
CACM	one inch perforated paper tape for information interchange proposed american standard
CACM	euler a generalization algol and its formal definition part i a method for defining programming languages is developed which introduces a rigorous relationship between structure and meaning the structure of a language is defined by a phrase structure syntax the meaning in terms of the effects which the execution of a sequence of interpretation rules exerts upon a fixed set of variables called the environment there exists a one to one correspondence between syntactic rules and interpretation rules is determined by the sequence of corresponding syntactic reductions which constitute a parse the individual interpretation rules are explained in terms of an elementary an d obvious algorithmic notation a constructive method for evaluating a text is provided and for certain decidable classes of languages their unambiguity is proved as an example a generalization of algol is described in full detail to demonstrate that concepts like block structure procedures parameters etc can be defined adequately and precisely by this method
CACM	serrev algorithm 273 c1
CACM	generation of hilbert derived test matrix algorithm 274 f1
CACM	complete elliptic integral of the second kind algorithm 56 s21
CACM	solution of transcendental equations by series reversion an algorithm is developed for expressing the solution y of the equation f y g x as a power series in x   x0 when f and g are given as power series and the root y0 is known at y x0 the algorithm is illustrated for the equation y y x i e 1 y ln 1 y ln 1 x
CACM	a formal semantics for computer languages and its application in a compiler compiler a semantic meta language has been developed for representing the meanings of statements in a large class of computer languages this meta language has been the basis for construction of an efficient functioning compiler compiler an informal discussion of the meta language based on the example of a complete translator for a small language is presented
CACM	on the normalization requirement of divisor in divide  and  correct methods this paper presents an analysis on the normalization requirement of the divisor in a divide and correct method this analysis is made subject to the condition that not more than one correction is required to obtain the true quotient character from the trial estimate got from the division of a two precision segment of every partial remainder by a suitably rounded single precision divisor this segmented division is denoted here as a 2 1 precision basic division it is found that the normalization requirement could be narrowed down to a smaller range of divisors provided the magnitude of the character next to the leading character of the divisor is known if however the normalization is to be eliminated one has to choose proper higher precision segments of operands for the basic division also considered is the possibility of eliminating the normalization by an increase on the number of corrections on the quotient estimate got from a 2 1 precision basic division it is shown that such a scheme is economical only for small radices
CACM	the alcor illinois 7090 7094 post mortem dump a dump technique for programs written in algol 60 is described this technique provides an intelligible analysis of an unsuccessful computation process in terms of the original source program
CACM	chebyschev curve fit revised algorithm 318 e2
CACM	chebyschev curve fit algorithm 91 e2
CACM	eigenvectors of a 2n x 2n matrix it has been known that the eigenvalues of a certain 2n x 2n matrix can be obtained by use of two smaller matrices of order n which can be easily constructed an algorithm is given to obtain the eigenvectors of the 2n x 2n matrix by use of the eigenvectors of the smaller matrices
CACM	an online editor an online interactive system for test editing is described in detail with remarks on the theoretical and experimental justification for its form emphasis throughout the system is on providing maximum convenience and power for the user notable features are its ability to handle any piece of text the content searching facility and the character by character editing operations the editor can be programmed to a limited extent
CACM	a simscript fortran case study two programs for a vehicle dispatching model one written in 7040 simscript and the other in 7040 fortran iv are compared the comparison is made in terms of basic program design decisions storage requirements computer time used and the ease of making changes in the simscript program the primary design considerations center around the choice of model variables model changing events and model testing in the fortran program basic design problems relate to the representation of the passage of time the allocation of storage and the organization of input data the comparison of these differently designed programs shows that the simscript program uses more computer storage and more computer time but requires fewer program changes to introduce model revisions
CACM	algorithms for finding a fundamental set of cycles for an undirected linear graph given the adjacency matrix of the graph the algorithm presented in this paper finds a spanning tree and then constructs the set of fundamental cycles our algorithm is slower than an algorithm presented by welch by a ratio of n 3 n is the number of nodes but requires less storage for graphs with a large number of nodes and edges when storage is limited our algorithm is superior to welchs however when the graphs are small or machine storage is very large welchs algorithm is superior timing estimates and storage requirements for both methods are presented
CACM	a system organization for resource allocation this paper introduces a system for resource management using the concepts of process facility and event except for the processor no attempt has been made to give serious suggestions for the policy to be followed for resource allocation however a basic framework is provided in which a system analyst can express solutions to resource management problems the paper is divided into a tutorial presentation a description of the system primitives and a small collection of examples of the use of the primitives
CACM	the laconiq monitor time sharing for online dialogues the laconiq laboratory computer online inquiry monitor was developed primarily to support non numerical applications such as retrieval from very large files by means of a dialogue between a system user and a retrieval application the monitor was designed so that it could work with a small computer an ibm system 360 30 therefore techniques for resource allocation were important for this reason the use of core storage computational facilities and input output were all scheduled an unusual feature of the system is that it is event driven rather than clock driven the program segments called into execution by the remote crt consoles are invariably run to completion rather than rolled out to be brought back at a later time
CACM	a multiprogramming environment for online data acquis ition and analysis an experimental system for acquis ition and analysis of large bodies of data derived from scientific experiments is described its architecture and implementation is largely based on certain objectives and characteristics of a general data analysis scheme early applications have been oriented towards the investigation of data obtained in biological research some of the problems encountered by the chosen approach are discussed
CACM	magnetic tape labels for information interchange proposed usa standard
CACM	recorded magnetic tape for information interchange 200 cpi nrzi proposed usa standard
CACM	finding a solution of n functional equations in n unknown algorithm 314 c5
CACM	the damped taylors series method for minimizing a sum of squares and for solving systems of nonlinear equations
CACM	solution of simultaneous non linear equations algorithm 316 c5
CACM	permutation algorithm 317 g6
CACM	on the expected gain from adjust ing matched term retrieval systems a file adjustment procedure based on maximizing the bayes expected gain proposed for matched term retrieval systems the expected gain and its probability distribution are derived as a function of 1 the prior proportion of omitted terms and 2 the coefficient of separation between two distributions corresponding to values of an adjustment statistic an example evaluates the gain parameters for a typical information retrieval system
CACM	a computer system for inference execution and data retrieval this paper presents a rand project concerned with the use of computers as assistants in the logical analysis of large collections of factual data a system called relational data file was developed for this purpose the relational data file is briefly detailed and problems arising from its implementation are discussed
CACM	automatic data compression the information explosion noted in recent years makes it essential that storage requirements for all information be kept to a minimum a fully automatic and rapid three part compressor which can be used with any body of information to greatly reduce slow external storage requirements and to increase the rate of information transmission through a computer is described in this paper the system will also automatically decode the compressed information on an item by item basis when it is required the three component compressors which can be used separately to accomplish their specific tasks are discussed nupak for the automatic compression of numerical data anpak for the automatic compression of any information and iopak for further compression of information to be stored on tape or cards
CACM	methods for analyzing data from computer simulation experiments this paper addresses itself to the problem of analyzing data generated by computer simulations of economic systems we first turn to a hypothetical firm whose operation is represented by single channel multistation queueing model the firm seeks to maximize total expected profit for the coming period by selecting one of five operating plans where each plan incorporates a certain marketing strategy an allocation of productive inputs and a total cost the results of the simulated activity under each plan are subjected to an f test two multiple comparison methods and a multiple ranking method we illustrate compare and evaluate these techniques the paper adopts the position that the particular technique of analysis possibly not any one of the above chosen by the experimenter should be an expression of his experimental objective the f test tests the homogeneity of the plans multiple comparison methods quantify their differences and multiple ranking methods directly identify the one best plan or best plans
CACM	an experimental model of system 360 the problem of predicting the performance of modern computer systems is formidable one general technique which can ease this problem is macroscopic simulation this paper reports on the applicability of that technique to system 360 the paper describes an experimental model of system 360 its hardware software and its environment the measures of system performance produced by the model consist of statistics relating to turnaround time throughput hardware utilization software utilization and queueing processes the model is mechanized in simscript and consists of some 1750 statements an auxiliary programs the job generator creates automatically the properties of system 360 jobs that get simulated
CACM	george 3 a general purpose time sharing and operating system an operating system is described which will run on a wide variety of configurations of the i c t 1900 and can handle a large number of online console users while at the same time running several off line background jobs the system is not oriented towards either mode and can be either a batch processing system such as the atlas supervisor ibsys or gecos or a multiaccess system resembling to the user ctss or multics or both simultaneously depending on the installation which can adjust the schedulers both online users and off line jobs use a common command language the system includes a multilevel device independent file store
CACM	absolute value and square root of a complex number algorithm 312 a2
CACM	multi dimensional partition generator algorithm 313 a1
CACM	chebyschev quadrature algorithm 279 d1
CACM	sharer a time sharing system for the cdc 6600 a time sharing system embedded within the standard batch processing system for the cdc 6600 is described the system is general purpose and file based providing facilities for file input manipulation editing compilation and conversational execution it uses a simple scheme for system extension for a machine with only one relocation and memory bound register no attempt was made to use reentrant code or to simulate segmentation or paging implementation time was approximately six man years with the majority of the code being written in fortran
CACM	a stopping criterion for polynomial root finding when searching for the root of a polynomial it is generally difficult to know just when to accept a number as an adequate approximation to the root in this paper an algorithm is presented which allows one to terminate the iteration process on the basis of calculated bounds for the roundoff error which occurs in evaluating the polynomial this stopping criterion has been tested on numerous examples and has been found to serve as a satisfactory means for accepting a complex number as a zero of a real polynomial
CACM	on computing the fast fourier transform cooley and tukey have proposed a fast algorithm for computing complex fourier transform and have shown major time savings in using it to compute large transforms on a digital computer with n a power of two computing time for this algorithm is proportional to n log2 n a major improvement over other methods with computing time proportional to n 2 in this paper the fast fourier transform algorithm is briefly reviewed and fast difference equation methods for accurately computing the needed trigonometric function values are given the problem of computing a large fourier transform on a system with virtual memory is considered and a solution is proposed this method has been used to compute complex fourier transforms of size n 2 16 on a computer with 2 15 words of core storage this exceeds by a factor of eight the maximum radix two transform size with fixed allocation of this amount of core storage the method has also been used to compute large mixed radix transforms a scaling plan for computing the fast fourier transform with fixed point arithmetic is also given
CACM	multiprogramming under a page on demand strategy a model of multiprogramming for a particular computer system using a page on demand strategy is developed analysis of this model is used to predict performance measured by the average usage of the cpu when user programs are typical of those arising from an interactive time sharing environment the effect of several hardware modifications is also analyzed a parameter readily calculated from the hardware characteristics and the program statistics is proposed for gauging the effect of multiprogramming
CACM	a grammar base question answering procedure the subject of this paper is a procedure for the automatic retrieval of certain segments of stored information either explicitly or implicitly represented through questions posed in natural language sentences this procedure makes use of a sentence recognition device for the class of grammars which will correctly decide between the grammatical and ungrammatical sentences of a natural language it is possible to make use of a recognition device of this sort for the following reason much data is fully expressible as a set of sentences in a natural language a set which can be exhaustively and exclusively generated by a grammar based upon the rules of this grammar a sentence recognizer will evaluate sentences questions in the normal situation since the recognition function succeeds just in case the posed question is drawn from the set of sentences expressing the data or more correctly is grammatical in terms of the grammar for this set of sentences sentence recognition itself is a procedure for retrieving information when the recognition function succeeds its value represents the requested information
CACM	three fonts of computer drawn letters detailed descriptions are given for three fonts of letters letter shapes are entirely described by numbers the basic vectors are in a general form so the fonts may be easily drawn on a variety of computers and cathode ray tubes the fonts include both upper and lower case roman letters mathematical signs and upper and lower case greek letters design of the fonts is described however the principal contribution of this paper concerns the fonts themselves
CACM	decomposition programming an analysis of matrix substructure a petroleum blending problem was analyzed in order to compare the primal and primal dual decomposition algorithms in the course of the analysis a substructure was discovered which has relevance to the relative performance of the two algorithms and to their absolute performance as compared with a standard primal simplex solution without decomposition
CACM	the ml i macro processor a general purpose macro processor called ml i is described ml i has been implemented on the pdp 7 and i c t atlas 2 computers and is intended as a tool to allow users to extend any existing programming language by incorporating new statements and other syntactic forms of their own choosing and in their own notation this allows a complete user oriented language to be built up with relative ease
CACM	the remaining trouble spots in algol 60 this paper lists the ambiguities remaining in the language algol 60 which have been noticed since the publication of the revised algol 60 report in 1963
CACM	the hardware software complementarity
CACM	a marovian model of the university of michigan executive system a mathematical model of a computers executive system is postulated and its parameters estimated with the aid of extensive data on the systems operation although simplifying assumptions are made the results predicted by the model agree reasonable well with actual results the model is used to study the effects of changes in the executive system and in one of its compilers further applications of the model are discussed
CACM	dad the c s i r o operating system the design and implementation of the c s i r o operating system dad is described in detail this system is designed for the control data 3600 using a large drum backing store and is intended to allow the integration of a remote console display subsystem into a conventional job stack environment the use of the drums the buffering of input and output on slow peripherals and the execution of normal job stack work are described the display subsystem is described only as it integrates into the rest of the system the techniques found useful in the development of dad are given and an assessment is made of the validity of various design decisions performance figures based on several months of operation are tabulated
CACM	a comment on index register allocation a technique is presented to reduce the enumeration required by a known procedure for optimal index register allocation in straight line programs this technique is based on the construction of a link diagram which shows at any step the future occurrences of indexes which must be loaded into index registers this diagram determines in advance the required register configuration at certain steps of the program so that the program is subdivided into separate portions to which the allocation procedure may be applied independently
CACM	dynamic computation of derivatives it is shown how wengerts procedure for computation of derivatives can be implemented conveniently by use of compiler generated complex addition subtraction and linkage to complex arithmetic subroutines evaluation of a function and derivative proceed in parallel as in wengerts procedure but with the imaginary parts of variables declared complex bearing the values of the derivatives of the real parts this technique provides a simple way to compute the derivatives of a function without the need for deriving and programming the evaluation of explicit formulas for the derivatives
CACM	prime number generator 1 algorithm 310 a1
CACM	prime number generator 2 algorithm 311 a1
CACM	prime number generator 1 prime number generator 2 algorithm 35 a1 algorithm 310 a1 algorithm 311 a1
CACM	an algorithm for class scheduling with section preference an algorithm for assignment of students to classes in a fixed time schedule that allows students to give a preference for sections within courses is given if consistent with the objective of balanced sections these preferences will be honored the algorithm is more stochastic than monte carlo in nature results are given that compare it to a nonpreference assignment algorithm
CACM	a language for modeling and simulating dynamic systems the general objective of this language is to facilitate both the modeling and experimental aspects of simulation studies the ability to represent systems containing highly interactive processes is an essential feature the nature of the language and the role of the process concept is presented by means of an extended example
CACM	a microprogrammed implementation of euler on ibm system 360 model 30 an experimental processing system for the algorithmic language euler has been implemented in microprogramming on an ibm system 360 model 30 using a second read only storage unit the system consists of a microprogrammed compiler and a microprogrammed string language interpreter and of an i o control program written in 360 machine language the system is described and results are given in terms of microprogram and main storage space required and compiler and interpreter performance obtained the role of microprogramming is stressed which opens a new dimension in the processing of interpretive code the structure and content of a higher level language can be matched by an appropriate interpretive language which can be executed efficiently by microprograms on existing computer hardware
CACM	computer formulation of the equations of motion using tensor notation a means is described for extending the area of application of digital computers beyond the numerical data processing stage and reducing the need for human participation in the formulation of certain types of computer problems by the use of tensor calculus and a computer language designed to facilitate symbolic mathematical computation a method has been devised whereby a digital computer can be used to do non numeric work that is symbolic algebraic manipulation and differentiation to illustrate the techniques involved a digital computer has been used to derive the equations of motion of a point mass in a general orthogonal curvilinear coordinate system since this operation involves a formulation in terms of first  and second order differential coefficients it provides a good demonstration of a computers capability to do non numeric work and to assist in the formulation process which normally precedes the numerical data processing stage moreover this particular problem serves to illustrate the advantages of the mathematical techniques employed with the program prepared for this purpose the computer will derive the equations of motion in any coordinate system requested by the user results are presented for the following coordinate systems cylindrical polar spherical polar and prolate spheroidal
CACM	tele cupl a telephone time sharing system a general purpose remote access computing system is described that employs twelve key keyboard telephones as terminals audio output is provided directly to the telephone terminals but the system will normally be used in conjunction with remotely located high speed printing devices the system is a compatible extension of an existing batch processing system a significant element of the system is a scheme for transmitting alphanumeric information by single strokes on a numeric keyboard the programmed scanner uses context to eliminate the ambiguity in transmission
CACM	legal safeguards to insure privacy in a computer society
CACM	toward standards for handwritten zero and oh
CACM	gamma function with arbitrary precision algorithm 309 s14
CACM	parsing of decision tables reduction in the size of decision tables can be accomplished by several techniques the techniques considered in this paper are on the parsing of decision tables with regard to horizontal and vertical data structures job identity hardware and job priorities and context relationships such parsing rests upon some conventions for the linkage of decision tables
CACM	an efficient machine independent procedure for garbage collection in various list structures a method for returning registers to the free list is an essential part of any list processing system in this paper past solutions of the recovery problem are reviewed and compared a new algorithm is presented which offers significant advantages of speed and storage utilization the routine for implementing this algorithm can be written in the list language with which it is to be used thus insuring a degree of machine independence finally the application of the algorithm to a number of different list structures appearing in the literature is indicated
CACM	a comparison of batch processing and instant turnaround a study of the programming efforts of students in an introductory programming course is presented and the effects of having instant turnaround a few minutes as opposed to conventional batch processing with turnaround times of a few hours are examined among the items compared are the number of computer runs per trip to the computation center program preparation time keypunching time debugging time number of runs and elapsed time from the first run to the last run on each problem even though the results are influenced by the fact that bonus points were given for completion of a programming problem in less than a specified number of runs there is evidence to support instant over batch
CACM	on compiling algorithms for arithmetic expressions this paper deals with algorithms concerning arithmetic expressions used in a fortran iv compiler for a hitac 5020 computer having n accumulators the algorithms generate an object code which minimizes the frequency of storing and recovering the partial results of the arithmetic expressions in cases where there are several accumulators
CACM	the aed free storage package the most fundamental underlying problem in sophisticated software systems involving elaborate changing data structure is dynamic storage allocation for flexible problem modeling the free storage package of the aed 1 compiler systems allows blocks of available storage to be obtained and returned for reuse the total available space is partitioned into a hierarchy of free storage zones each of which has its own characteristics blocks may be of any size and special provisions allow efficient handling of selected sizes control of shattering and garbage collection and sharing of physical space between zones the routines of the package perform high level functions automatically but also allow access and control of fine internal details as well
CACM	contextual understanding by computers a further development of a computer program eliza capable of conversing in natural language is discussed the importance of context to both human and machine understanding is stressed it is argued that the adequacy of the level of understanding achieved in a particular conversation depends on the purpose of that conversation and that absolute understanding on the part of either humans or machines is impossible
CACM	a computer technique for displaying n dimensional hyperobjects a digital computer and automatic plotter have been used to generate three dimensional stereoscopic movies of the three dimensional parallel and perspective projections of four dimensional hyperobjects rotating in four dimensional space the observed projections and their motions were a direct extension of three dimensional experience but no profound feeling or insight into the fourth spatial dimension was obtained the technique can be generalized to n dimensions and applied to any n dimensional hyperobject or hypersurface
CACM	symmetric polynomials algorithm 305 c1
CACM	permutations with repetitions algorithm 306 g6
CACM	symmetric group characters algorithm 307 a1
CACM	generation of permutations in pseudo lexicographic order algorithm g6
CACM	permutation generator permutation in lexicographical order permute generation of permutations in lexicographical order algorithm 87 g6 algorithm 102 g6 algorithm 130 g6 algorithm 202 g6
CACM	transport transportation problem algorithm 258 h algorithm 293 h
CACM	the mutual primal dual method algorithm 285 h
CACM	airy function algorithm 301 s20
CACM	a method for finding hamilton paths and knights tours the use of warnsdorffs rule for finding a knights tour is generalized and applied to the problem of finding a hamilton path in a graph a graph theoretic justification for the method is given
CACM	description of basic algorithm in detab 65 preprocessor the basic algorithm for the conversion of decision tables into cobol code is contained in the generator portion of the detab 65 preprocessor the generator analyzes a decision table and produces simple cobol conditional statements core storage is saved by using queueing techniques and extensive indexing and also by outputting the code as it is generated a line at a time the only optimization attempted is the elimination of obviously unnecessary tests on certain conditions in the decision table since the preprocessor and this language associated with it were developed for cobol users the preprocessor was written in a modular form in required cobol 61
CACM	a language independent macro processor a macro processor is described which can be used with almost any source language it provides all features normally associated with a macro facility plus the ability to make arbitrary transformations of the argument strings the program is used at the basser computing department university of sydney sydney australia to process text for eight different compilers
CACM	optimal starting values for newton raphson calculation of sqrt x the problem of obtaining starting values for the newton raphson calculation of sqrt x on a digital computer is considered it is shown that the conventionally used best uniform approximations to sqrt x do not provide optimal starting values the problem of obtaining optimal starting values the problem of obtaining optimal starting values is stated and several basic results are proved a table of optimal polynomial starting values is given
CACM	on the representation of symmetric polynomials relations are given between certain symmetric polynomials in the light of the theory of the symmetric group such an approach unifies earlier work and lends insight to previously published work by aaron booker a generalization of graeffes root squaring technique for the determination of the roots of a polynomial is suggested
CACM	plotting a function of three independent variables a method is developed for constructing an approximate plot of a function of three independent variables the plot is similar to a conventional contour map except that there are three scales to represent the independent variables scale values of the three independent variables are added vectorially and the value of the function is then read from the values associated with nearby contours
CACM	implementing phrase structure productions in pl i a method is described for implementing the productions of a context free phrase structure grammar in a pl i procedure whose structure and statements parallel the structure and notation of the grammar
CACM	string processing techniques the internal organization of string processing systems is discussed six techniques for data structures are presented and evaluated on the basis of 1 creation of strings 2 examination of strings and 3 alteration of strings speed of operation storage requirements effect on paging and programmer convenience are also considered one of the techniques single word linked blocks is used in an example demonstrating an implementation of a snobol string processing language on an ibm system 360
CACM	a user oriented time shared online system an existing system and planned additions within the data processing laboratory of the brain research institute at ucla is described the system represents an attempt to provide research workers of the institute with the ability to interact directly with a highly sophisticated digital computing complex in the most direct and simple fashion possible it is anticipated that with the accumulation of experience using the present system significant advances will be possible in the system design through determination of interface parameters between the biological scientist and the digital computer
CACM	the simulation of time sharing systems the development of new large scale time sharing systems has raised a number of problems for computation center management not only is it necessary to develop an appropriate hardware configuration for these systems but appropriate software adjustments must be made unfortunately these systems often do not respond to changes in the manner that intuition would suggest and there are few guides to assist in the analysis of performance characteristics the development of a comprehensive simulation model to assist in the investigation of these questions is described in this paper the resulting model has a general purpose design and can be used to study a variety of time sharing systems it can also be used to assist in the design and development of new time sharing algorithms or techniques for the sake of efficiency and greater applicability the model was implemented in a limited fortran subset that is compatible with most fortran iv compilers the use of the simulation is demonstrated by a study of the ibm 360 67 time sharing system
CACM	an adaptive quadrature procedure with random panel sizes algorithm d1
CACM	normal curve integral algorithm 304 s15
CACM	incomplete beta ratio algorithm 179 s14
CACM	eigenvalues of a real symmetric matrix by the qr method algorithm 253 f2
CACM	eigenvalues and eigenvectors of a real symmetric matrix by the qr method algorithm 254 f2
CACM	generalized least squares fit by orthogonal polynomials algorithm 296 e2
CACM	real error function erf x algorithm 123 s15
CACM	error function large x algorithm 180 s15
CACM	complementary error function large x algorithm 181 s15
CACM	gauss algorithm 209 s15
CACM	normal distribution function algorithm 226 s15
CACM	procedure for the normal distribution functions algorithm 272 s15
CACM	normal curve integral algorithm 304 s15
CACM	a generalized bairstow algorithm the bairstow algorithm is generalized to the case of a polynomial which is itself a linear combination of polynomials satisfying a three term recursion convergence properties of the method are derived
CACM	storage allocation in a certain iterative process a method of core storage allocation in a certain iterative process is described and estimates of the machine time required are given the method is applicable to iterative processes in which input data items once chosen are never again needed in this method the input data is continuously relocated and the space made available apportioned to the output tables when an overflow occurs some important special cases are considered in which considerable simplification occurs
CACM	pl i list processing the concepts of list processing have been introduced into the pl i language with these new facilities it is possible to write pl i procedures that operate on simple and complex data list organizations most list processing languages have suffered from their inability to deal directly with complex data structures and or from their inability to perform the complete range of programming language operations upon the data list structures these two problems have been eliminated in the list processing facilities of pl i the basic concepts of list processing and the philosophy of the pl i language extensions are discussed in addition several detailed list processing examples are provided
CACM	dialog a conversational programming system with a graphical orientation dialog is an algebraic language for online use with a graphical input output console device it is a computational aid for the casual user which provides basic facilities for graphical and numeric input and display online and off line program preparation and storage and hard copy presentation of results use of the system requires a minimum of experience or instruction since the growth of an overlaying system control language has been prevented and there are no processor oriented statements like variable type or dimension declarations moreover in the online situation the processor interacts with the graphical keyboard on a character by character basis so as to restrict the programmers choice of input symbols to those which are syntactically correct dialog has been in daily operation at the iit research institute since february 1966
CACM	pitch period determination of speech sounds a computer procedure which determines pitch periods by the recognition of the peak structure of the speech waveform is described speech sounds were sampled by a microphone and an analog to digital converter attached to an interconnected ibm 7090 pdp 1 system these utterances were recorded at the normal noise level of the computer room but were not band compressed or phase distorted in any manner a sequence of operations defined on the speech wave selects a list of points along the waveform as candidates for pitch markers these markers are validated by an error detection and correction procedure about 95 percent of the pitch periods were recognized correctly within 1 to 2 times real time on the ibm 7090
CACM	a model for a multifunctional teaching system a teaching system model that was incorporated into an operating system of a large computer is described the model transferred control to the operating system to execute functions other than teaching and then recovered control in order to resume teaching the teaching system abac ii was written to run under the operating system ibsys for the ibm 7044 graphic system because the teaching system automatically terminated and rescheduled itself a student studying a course presented at a cathode ray display terminal could switch readily between student mode and programmer mode during the latter the full resources of the operating system language processors compilers library and users programs were at his disposal he could for example write assemble debug and execute at the terminal a program written in any language processed by the operating system a course could therefore include text material interleaved with programming problems which the student could solve without leaving the terminal exercises in simulation and gaming could also be provided the implications of a teaching system with this degree of flexibility for industrial and executive training as well as academic education are discussed in addition the advantages of this type of system for computer programming and operation are also considered
CACM	string similarity and misspellings the problem of programming a computer to determine whether or not a string of characters is a misspelling of a given word was considered a numberof algorithms were evaluated some proposed by other writers some by the author these techniques were tested on a collection of misspellings made by students at various grade levels while many of the methods were clearly unsatisfactory some gave as few as 2 1 percent incorrect determinations
CACM	a simple technique for digital division a simple and economical method for digital division is described the method is suitable for divisors whose leading character is either radix less one or is unity with the next character equal to zero also the method is direct and needs only half the number of arithmetic operations needed by a variant of the harvard iterative method described by gilman which is suitable for similar divisors
CACM	an algorithm for generating permutations an algorithm is described which under repeated application generates all permutations of k elements only the previously generated permutation the constant k and a temporary index are needed starting with a particular ordering of k elements abcd repeated application of the algorithm will generate k 1 additional permutations by k 1 successive rotations from the initial circular ordering of k objects another circular ordering can be obtained by rotating the k 1 lowest elements for each new k 1 circular ordering another k 2 can be obtained by rotating the k 2 lowest elements by continuing in this manner applications of the algorithm will generate all k 1 circular orderings or since each circular ordering yields k permutations the algorithm generates all k permutations
CACM	on the computer enumeration of finite topologies the problem of enumerating the number of topologies which can be formed from a finite point set is considered both theoretically and computationally certain fundamental results are established leading to an algorithm for enumerating finite topologies and computed results are given for n 7 an interesting side result of the computational work was the unearthing of a theoretical error which had been induced into the literature the use of the computer in combinatorics represents chronologically an early application and this side result underscores its continuing usefulness in this area
CACM	airy function algorithm 301 s20
CACM	transpose vector stored array algorithm 302 k2
CACM	least squares fit by orthogonal polynomials algorithm 28 e2
CACM	numerical solution of the polynomial equation algorithm 300 c2
CACM	chebyshev quadrature algorithm 279 d1
CACM	parallel numerical methods for the solution of equations classical iterative procedures for the numerical solution of equations provide at each stage a single new approximation to the root in question a technique is given for the development of numerical procedures which provide at each stage several approximations to a solution of an equation the s8everal approximations obtained in any iteration are computationally independent making the methods of interest in a parallel processing environment convergence is insured by extracting the best information at each iteration several families of numerical procedures which use the technique of the procedures in a parallel processing environment are developed and measurements of these statistics are reported these measurements are interpreted in a parallel processing environment in such an environment the procedures obtained are superior to standard algorithms
CACM	pose a language for posing problems to a computer a language pose is described which is a drastic departure from the fortran algol type though it does utilize fortran formula and logic representations and actually contains fortran vi as a subset with the new language the user need only describe his problem in equation like form the method of solution is automatically provided in conjunction with the translation from equation form to computer instruction in this way the pose language user can solve difficult computational problems like the solution of differential equation without requiring a knowledge of numerical methods or the intricacies of computer subroutine logic essentially all clerical operations now required for fortran programming have been automated so that the pose programmer need not be concerned with these details
CACM	a multiprogramming monitor for small machines int a combination hardware software monitor designed to control a wide variety of real time input output devices is described the simple hardware additions provide a uniform device to machine interface for such elements as keyboards graphic input devices and interval timers the software relieves the user program from the details of input output timing buffering and task scheduling and provides parallel processing capability user programs communicate with the monitor through a small set of meta instruction which consists mostly of machine language subroutine calls
CACM	further analysis of a computing center environment empirical distributions of program lengths execution times processing times and loading times of over 10 000 jobs serviced in a university computing center environment are presented the data are subdivided according to certain characteristics of users and jobs to obtain selected empirical conditional distributions of those time properties as well as statistical measures of other interesting properties the results are interpreted in terms of the properties of the system studied
CACM	an experimental comparison of time sharing and batch processing the effectiveness for program development of the mit compatible time sharing system ctss was compared with that of the ibm ibsys batch processing system by means of a statistically designed experiment an identical set of four programming problems was assigned to each of a group of four programming subjects influences external to the systems such as the sequence of problem solution and programmer and problem characteristics were specified as design factors in the experiment data was obtained for six variables e g programmer time computer time elapsed time etc which were considered to be definitive of system effectiveness and analysis of variance techniques were employed to estimate system differences in these variables after differences due to the design factors had been eliminated statistical analysis of the experimental results provided strong evidence of important system differences as well as a critique of the experimental design itself with implications for further experimentation
CACM	chi squared integral algorithm 299 s15
CACM	coulomb wave functions algorithm 300 s22
CACM	numerical integration of function that has a pole it is common to need to integrate numerically functions that diverge somewhere outside the range of integration even if the divergence occurs quite far away integration formulas like simpsons that depend on fitting a polynomial usually will be inaccurate near a pole they will be very bad a method is described that gives formulas that will integrate functions of this kind accurately if the orders and positions of the poles are known explicit formulas are given that are easy to use on an automatic computer it is shown that they can be used for some other singularities as well as poles if the integral converges integration can be carried to the singularity the accuracy of the integration with a pole of second order is discussed and as an example the new formula is compared with simpsons the new formulas are useful even far from the pole while near the pole their advantage is overwhelming
CACM	scheduling university course examinations by computer a new approach to the problem of scheduling course examinations is presented in principle an examination schedule which requires a minimum number of examination periods and satisfies the constraint that no student be required to take two examinations simultaneously can be found in two steps first course which may have their examinations scheduled at the same period are grouped together in all possible ways then a minimum number of these groups such that each course is included at least once are selected by removing multiple occurrences of courses and then scheduling each group at a different period a minimal schedule can be obtained known algorithms for carrying out these procedures are prohibitively expensive approximations to the ideal procedure outlined above are given which yield nonminimal but feasible schedules with a very small expenditure of time results of experiments using these techniques are given these are encouraging and indicate that further experimentation would be worthwhile
CACM	a method for the solution of transportation problems with tall matrices a method is presented for the solution of the transportation problem having a cost matrix with few columns the computer implementation of this method shows it to be very fast and efficient application are indicted for the personnel classification problem as well as the classical transportation problem an example is worked out in detail
CACM	scheduling project networks some of the basic concepts and terminology of project networking are developed the critical path algorithm incorporated in the c e i r proprietary scheduling system ramps resource allocation and multi project scheduling is described the error detection and network analysis features of the algorithm are also described
CACM	top to bottom parsing rehabilitated this note is concerned with the efficiency of the top to bottom parsing algorithm as used in connection with programming language grammars it is shown for instance that retracing of unprofitable paths can often be eliminated by a suitable rearrangement of the productions defining the grammar the essential weakness of the method is in dealing with complicated syntactic structures which are in practice only sparsely occupied e g arithmetic expressions
CACM	one pass compilation of arithmetic expressions for a parallel processor under the assumption that a processor may have a multiplicity of arithmetic units a compiler for such a processor should produce object code to take advantage of possible parallelism of operation most of the presently known compilation techniques are inadequate for such a processor because they produce expression structures that must be evaluated serially a technique is presented here for compiling arithmetic expressions into structures that can be evaluated with a high degree of parallelism the algorithm is a variant of the so called top down analysis technique and requires only one pass of the input text
CACM	a proposal for definitions in algol an extension to algol is proposed for adding new data types and operators to the language definitions may occur in any block heading and terminate with the block they are an integral part of the program and are not fixed in the language even the behavior of existing operators may be redefined the processing of text containing defined contexts features a replacement rule that eliminates unnecessary iterations and temporary storage examples of definition sets are given for real and complex matrices complex numbers file processing and list manipulation
CACM	an algorithm for generating root locus diagrams a technique for using a digital computer to draw both ordinary and time lag root locus diagrams is described ordinary diagrams are drawn much faster and more accurately than ever before time lag diagrams which had been impossible to obtain are drawn with the same speed and accuracy as ordinary diagrams
CACM	tensor calculations on computer appendix in the main text of the paper comm acm 9 12 dec 196 864 a formac program was discussed which is capable of calculating various quantities of interest in tensor calculus this appendix is intended as an example of the program output chrisoffel symbols calculated for 12 basic orthogonal coordinate systems are listed
CACM	eigenvalues and eigenvectors of the symmetric system algorithm 297 f2
CACM	determination of the square root of a positive definite matrix algorithm 298 f1
CACM	error free methods for statistical computations neely has discussed computational error generated by some algorithms used to compute various statistics in the present paper methods are described which are error free simple in concept and usually less costly in machine time than those mentioned by neely
CACM	methods of evaluating polynomial approximations in function evaluation routines the method of nested multiplication is commonly used in function evaluation routines to evaluate approximation polynomials new polynomial evaluation methods have been developed in recent years which require fewer multiplications than nested multiplication and may therefore be preferable for use in function evaluation routines although some of these methods do not appear to be practically useful because of rounding error difficulties several methods of evaluating low degree polynomials have been found to be satisfactory three such methods are described and illustrated
CACM	computer typesetting of algol an application of computer aided typesetting is introduced a working method is described for publishing algol by computerized translation from hardware into reference representation computerized planning of typographical lay out and computerized control of a typesetting machine the point is made that experts in science technology and programming are guaranteed a correct algol documentation without spending valuable time and power on typographic considerations and proofreading
CACM	an efficient procedure for the generation of closed subsets an efficient algorithm is described for generating subsets of a set s which satisfy constraints of the form if s i is a member of the subset then s j must also be a member of the subset the algorithm has been programmed in the wisp language and successfully run on the ibm 7094 in connection with a routine to detect feedback in multidimensional iterative networks
CACM	an application of formac a nonlinear circuit analysis problem is stated and the way in which it was solved using formac is indicated the solution of the problem using formac was notable since several other methods that were tried failed the problem is straightforward although untenable by hand but nevertheless involved an elaborate use of the formac language the program was fairly large and utilized practically every command in particular it made extensive use of the part command several tricks were necessary in order to circumvent some of the shortcomings of the formac system this paper is more concerned with the use of programming techniques in formac than with the actual engineering problem although readers may be interested in the problem because it is stated in a general mathematical sense and could be of interest in areas other than circuit analysis
CACM	automatic dimensioning examples of algorithm that will accomplish automatic storage reservation without the need for explicit array declarations are described
CACM	on the automatic simplification of source language programs methods of simplification that can be applied automatically to programs written in an algol like language are discussed the simplifications are based on the form of the program and the knowledge obtained by a processor without any understanding of what the program is supposed to do these methods have been implemented in a processor called sure that accepts a program written in jovial and outputs an equivalent jovial program that may be shorter and may be executed faster than the original sure is described some of the problems encountered in automatic improvement at the source language level are discussed and further types of automatic program improvement are suggested
CACM	structure of a lisp system using two level storage in an ideal list processing system there would be enough core memory to contain all the data and programs described in this paper are a number of techniques that have been used to build a lisp system utilizing a drum for its principal storage medium with a surprisingly low time penalty for use of this slow storage device the techniques include careful segmentation of system programs allocation of virtual memory to allow address arithmetic for type determination and a special algorithm for building reasonably linearized lists a scheme for binding variables is described which is good in this environment and allows for complete compatibility between compiled and interpreted programs with no special declarations
CACM	application of level changing to a multilevel storage organization a technique for organizing the devices of a computer storage system is described this technique called the multilevel store provides a means for economically satisfying the requirements for very large storage capacities of certain data management and information retrieval systems the concept of level changing is introduced and its application to the multilevel store is discussed a possible means for physically organizing the information for efficient use of the multilevel store is presented
CACM	the emergence of a profession computer programming deals with an enormous variety of activities and is carried on by people with a great variety of backgrounds it seems clear that part but not all of this activity is evolving toward a distinct professional field but that the scope of this emerging profession and some of its economic social and educational characteristics are as yet by no means well defined in this paper these issues are examined and some opinions about them are expressed
CACM	stat pack a biostatistical programming package a package of fortran statistical programs for use on almost any small to medium size 40k characters or 8k words for which a fortran ii compiler exists is described and its availability is announced the major design criteria of ease of use ease of modification flexibility of input and detail of output are described
CACM	computer representation of planar regions by their skeletons any region can be regarded as a union of maximal neighborhoods of its points and can be specified by the centers and radii of these neighborhoods this set is a sort of skeleton of the region the storage required to represent a region in this way is comparable to that required when it is represented by encoding its boundary moreover the skeleton representation seems to have advantages when it is necessary to determine repeatedly whether points are inside or outside the region or to perform set theoretic operations on regions
CACM	testing a random number generator the first 1 000 000 numbers produced by the random number generator used in the general purpose systems simulator gpss were subjected to statistical tests the tests are described and the results of the tests are presented these particular tests indicate that the numbers are satisfactory it is recommended that suitable tests be applied to all random numbers used in computer simulations
CACM	programming the tabular method of analysis of variance for factorial experiments the ease of programming the tabular method of analysis of variance for complete factorial experiments in a fortran language is demonstrated in this method the total sum of squares is partitioned into orthogonal single degree of freedom sums of squares main effect and interaction sums of squares are then obtained by appropriate pooling of the single degree of freedom sums of squares program segments to accomplish the procedure are presented modifications to handle hierarchical designs and replicated experiments are mentioned a fortran ii program for an ibm 7094 is described briefly
CACM	a modified newton method for polynomials a modified newton method for polynomials is discussed it is assumed one has approximations for all the roots of the polynomial three variations are described if the roots are simple it is shown that under appropriate conditions two of the variations are cubically convergent
CACM	27 bits are not enough for 8 digit accuracy from the inequality 10 8 2 27 we are likely to conclude that we can represent 8 digit decimal floating point numbers accurately by 27 bit floating point numbers however we need 28 significant bits to represent some 8 digit numbers accurately in general we can show that if 10 p 2 q 1 then q significant bits are always enough for p digit decimal accuracy finally we can define a compact 27 bit floating point representation that will give 28 significant bits for numbers of practical importance
CACM	parameters for pseudo runge kutta methods the object of this note is to present a choice of the free parameters in the third  and fourth order pseudo runge kutta methods involving two points this choice of parameters causes a bound on the principal part of the truncation error term to be near the minimum for the fourth order method and at the minimum for the third order method
CACM	invariant imbeding and the numerical integration of boundary value problems for unstable linear systems of ordinary differential equations in such diverse areas as radiative transfer in planetary atmospheres and optimal guidance and control two point boundary value problems for unstable systems arise greatly complicating the numerical solution an invariant imbeding technique is presented which is useful in overcoming these frequently encountered instabilities and the results of some numerical experiments are given
CACM	problems in the statistical analysis of simulation experiments the comparison of means and the length of sample records research is continued into statistical analysis of simulation experiments containing autocorrelated time series it is shown how to estimate the lengths of sample records needed to use certain large sample results in measuring stability analogies between autocorrelated data and independent observations are described a way to test the difference of the mean of two experiments is suggested it is shown how the variance of the sample mean relates to the spectrum of the generating process and estimation of the quantities of interest is described the results expand the possibilities of statistical spectral analysis as applied to simulation experiments
CACM	sorting by replacement selecting in sorting by replacement selecting the expected length of a sequence beginning with the i th element i 1 is proved to be 2f in accordance with a conjecture of e h friend where f is the number of memory cells used the expected length of the j th sequence is determined to be f times a j th degree polynomial in e such that the value of this polynomial approaches 2 as j approaches infinity recursive formulas are obtained for both the mean and the standard deviation of the length of the j th sequence the mathematical proofs of these results are based upon the assumption that n the number of items to be sorted is infinite but it is shown that the error due to the finiteness of n approaches zero rapidly as n increases
CACM	exponential curve fit algorithm 295 e2
CACM	generalized least squared fit by orthogonal polynomials algorithm 296 e2
CACM	a use of fast and slow memories in list processing languages a scheme is described which permitting a substantial increase in memory space utilized to store list structured data it consists in reducing to one level a nonhomogeneous store composed of fast core and slow disk or drum memories the space available in slow memory is divided into pages each containing a given number of machine words the reduction to a one level memory is performed by a program which leaves the most often called pages in the fast memory when a new page from slow store is requested the page in core having the longest period of inactivity is transferred back to the slow store the complete scheme has been implemented in connection with a lisp embedding into algol using an ibm 7044 with 32k of core memory and disks gains in memory space were about 100 fold as often happens in programming applications the price of the additional space is computer time although the disks have an access time 10 4 times slower than core tests indicate that the actual slow down varied from 3 to 10 depending on the number of pages available in the fast store
CACM	time sharing on a computer with a small memory techniques to make time sharing attractive on a computer with a small central memory are presented small is taken to mean that only one user program plus a monitor will fit into the memory at any time the techniques depend on having two levels of secondary storage level 1 several times larger than the main memory and quite fast and level 2 many times larger and slower than level 1
CACM	an improvement to iterative methods of polynomial factorization methods of polynomial factorization which find the zeros one at a time require the division of the polynomial by the accepted factor it is shown how the accuracy of this division may be increased by dividing in order of both ascending and descending powers of the variable and choosing a crossover point which minimizes a very simply calculated error criterion
CACM	on the computation of least squares polynomials rounding error accumulated during digital computation of a least squares polynomial makes the computed polynomial only an approximation to the true least square polynomial a simple method for adjust ing the constant term of the computed polynomial to get a better approximation to the true least squares polynomial is described
CACM	a note on computing approximations to the exponential function two methods are discussed which result in near minimax rational approximations to the exponential function and at the same time retain the desirable property that the approximation for negative values of the argument is the reciprocal of the approximation for corresponding positive values these methods lead to approximations which are much superior to the commonly used convergents of the gaussian continued fraction for the exponential coefficients and errors are given for the intervals   5 ln 2 5 ln 2 and  ln 2 ln 2
CACM	ditran a compiler emphasizing diagnostics ditran diagnostic fortran is an implementation of asa basic fortran with rather extensive error checking capabilities both at compilation time and during execution of a program the need for improved diagnostic capabilities and some objectives to be met by any compiler are discussed attention is given to the design and implementation of ditran and the particular techniques employed to provide the diagnostic features the handling of error messages by a general macro approach is described special features which provide teaching aids for use by instructors are noted
CACM	watfor the university of waterloo fortran iv compiler watfor is an in core load and go compiler which has been implemented within the ibm 7040 44 operating system fortran iv was selected as the source language in order to achieve maximum language compatibility with other available compiling systems in particular the ibm 7040 44 fortran iv system the principal advantage of the watfor compiler is that it translates fortran iv programs at speeds of up to 100 statements per second since the compiler resides core there is virtually no system overhead and hence large batches of student programs may be processed very efficiently the compiler also provides extensive error diagnostics during both the compilation and the execution phases of a program run this feature makes the system attractive to both learners and learned users alike
CACM	uniform random algorithm 294 g5
CACM	data directed input output in fortran a statement which is similar to the namelist statement of fortran iv has been incorporated in the fortran 63 compiler the fortran 63 implementation allows a greater flexibility and simplicity than the fortran iv feature the hollerith names the location the mode and the dimensions of a variable can be discovered by means of standard fortran statements methods of using this information are illustrated in relation to general purpose data directed input and output routines some other uses such as matrix manipulation are discussed
CACM	a unifying computational method for the analysis of complete factorial experiments a computational method which may be used for the calculation of sums of squares in the analysis of variance of complete factorial experiments and in the computation of main effect or interaction means is described the method is elucidated as unifying since one method can be used for a variety of purposes each previously requiring different methods the programming advantages of such a method are obvious the following variants are discussed 1 the standard analysis of variance 2 analyses omitting certain levels of one or more factors 3 separate analyses for some levels of a factor or for combinations of levels of more than one factor these are performed simultaneously 4 the calculation of main effect or interaction means the mean expects the data in standard order and it leaves the data in that order so that many analyses of the same data can be performed without rearrangement the total sum of squares excluding a replication sum of squares is partitioned into all polynomial partitions and their interactions each with one degree of freedom this is so even if factors have unequally spaced factor levels
CACM	an interpretive input routine for linear programming in this descriptive article an input code is presented which greatly simplifies data input to any linear programming solution routine for subsequent use either as a pedagogical device or for solving rather small lp problems this latter limited use derives not at all from inherent limitations in the code itself but from an efficiency evaluation large lp problems would doubtless benefit from an input system more suited for bulk data handling than the input code described from a users standpoint input appears almost exactly as a textbook presentation of the lp problem limited only by a keypunchs inability to write subscripts etc the input interpreter scans column wise thus no fixed format data preparation is required the user may also under very general requirements only liberally use editorial comments throughout the input deck as an aid in identification e g of row constraints the article includes examples of input output from a solution routine presently in use and a skeleton flowchart of the input interpreter
CACM	a code for non numeric information processing applications in online systems a code has been specifically designed to simplify the internal information processing operations within an online computer system with respect to non numeric applications and to maximize the transfer rate of the information channel linking the system and the system user the code has direct application to problems in area such as information retrieval document classification computer aided teaching and text editing this code called ipc information processing code is an 8 bit code set constructed so that 7 6 5 and 4 bit subsets can be easily derived from the basic set the code set is organized so that simple binary operations can distinguish between the numeric alphabetic special symbol and control character codes the number of usable characters within the basic set size may be expanded either by use of escape codes included in the set or by suitable interpretation of otherwise unassigned codes on the basis of the requirements of local environments
CACM	system performance evaluation survey and appraisal the state of the art of system performance evaluation is reviewed and evaluation goals and problems are examined throughput turnaround and availability are defined as fundamental measures of performance overhead and cpu speed are placed in perspective the appropriateness of instruction mixes kernels simulators and other tools is discussed as well as pitfalls which may be encountered when using them analysis simulation and synthesis are presented as three levels of approach to evaluation requiring successively greater amounts of information the central role of measurement in performance evaluation and in the development of evaluation methods is explored
CACM	a universitys educational program in computer science after a review of the power of contemporary computers computer science is defined in several ways the objectives of computer science education are stated and it is asserted that in a north american university these will be achieved only through a computer science department the program at stanford university is reviewed as an example the appendices include syllabic of ph d qualifying examinations for stanfords computer science department
CACM	code extension procedures for information interchange proposed usa standard
CACM	procedures for the standardization process proposed usa standard
CACM	implementation of the sharer2 time sharing system a simple mechanism is described for the execution of part of a program with its own memory protection this allows such a program to act as a suboperating system an improved version of the sharer time sharing system using this feature is described
CACM	analysis of algorithms for the zero one programming problem this paper is concerned with a review and examination of several existing algorithms for the zero one programming problem computational experience is summarized the machine time and storage requirements of several of the algorithms are compared over several test problems of small and intermediate size computer experiments still provide little hope of solving problems with over 100 variables with a reasonable amount of machine time
CACM	computational linguistics in a ph d computer science program this report contains recommendations for a course curriculum on computational linguistics in a ph d computer science program a classification of the subject areas contained in computational linguistics is presented and ten courses in these areas are described a basic bibliography in computational linguistics is appended
CACM	index by subject to algorithms 1960 1968
CACM	multint algorithm 32 d1
CACM	eigenvalues and eigenvectors of a real general matrix f2
CACM	generator of random numbers satisfying the poisson distribution g5
CACM	an algorithm for deriving the equations of mathematical physics by symbolic manipulation a method is described whereby a digital computer can be used to derive the equations of mathematical physics in any curvilinear coordinate system requested by the user the effectiveness of the technique is demonstrated by using it to derive the navier stokes equations of fluid motion and the continuity equation to derive these equations by this method the user need know only the coordinate transformation equations relating the curvilinear coordinates of interest to an orthogonal cartesian triad when this program is used and the coordinate transformation equations are supplied as input the computer will derive the navier stokes equations and the continuity equation the equations obtained will be relative to the curvilinear coordinate system specified by the transformation equations used as input in this paper the emphasis is on theoretical considerations and methodology rather than on programming details results are presented for cylindrical polar and spherical polar coordinate systems
CACM	automatic generation of efficient lexical processors using finite state techniques the practical application of the theory of finite state automata to automatically generate lexical processors is dealt with in this tutorial article by the use of the aed rword system developed at m i t as part of the aed 1 system this system accepts as input description of the multicharacter items or of words allowable in a language given in terms of a subset of regular expressions the output of the system is a lexical processor which reads a string of characters and combines them into the items as defined by the regular expressions each output item is identified by a code number together with a pointer to a block of storage containing the characters and character count in the item the processors produced by the system are based on finite state machines each state of a machine corresponds to a unique condition in the lexical processing of a character string at each state a character is read and the machine changes to a new state at each transition appropriate actions are taken based on the particular character read the system has been in operation since 1966 and processors generated have compared favorably in speed to carefully hand coded programs to accomplish the same task lexical processors for aed o and mad are among the many which have been produced the techniques employed are independent of the nature of the items being evaluated if the word events is substituted for character string these processors may be described as generalized decision making mechanisms based upon an ordered sequence of events this allows the system to be used in a range of applications outside the area of lexical processing however convenient these advantages may be speed is the most important consideration in designing a system for automatic generation of a lexical processor the goal was a processor which completely eliminated backup or rereading which was nearly as fast as hand coded processors which would analyze the language and detect errors and which would be convenient and easy to use
CACM	solution of linear programs in 0 1 variables by implicit enumeration algorithm 341 h
CACM	roots of polynomials by a root squaring and resultant routine algorithm 340 c2
CACM	an algol procedure for the fast fourier transform with arbitrary factors algorithm 339 c6
CACM	algol procedures for the fast fourier transform algorithm 338 c6
CACM	correspondences of 8 bit and hollerith codes for computer environments a usasi tutorial standard
CACM	a phonological rule tester the design and implementation of a system to alleviate the problem of rule evaluation for the linguist in the area of phonology are presented it permits the user to define on line sets of rules statable within the framework presented in the sound patterns of english by chomsky and halle 1968 to define phonemes as bundles of specified distinctive features to define data as strings of phonemes with associated grammatical structure to test the effect of applying rules to the data and to store both the definitions and results the rule application facility described in detail was implemented by translating linguistic rules to rules in flip a format directed list processor embedded in lisp this made the system construction easy while providing sophisticated capabilities for the linguist the system is written in bbn lisp on the scientific data system 940 computer and is designed to be used on line in interactive fashion with control returned to the user after each command is executed
CACM	practical error coefficients in the integration of periodic analytic functions by the trapezoidal rule theoretical and practical values of error coefficients useful in bounding the error in integrating periodic analytic functions with the trapezoidal rule are tabulated for various ranges of the parameters
CACM	approximate solution of initial boundary wave equation problems by boundary value techniques a new boundary value technique is proposed for the treatment of initial boundary value problems for linear and mildly nonlinear wave equations several illustrative examples are offered to demonstrate the ease with which the method can be applied
CACM	one line random number generators and their use in combinations some one line random number generators i e generators requiring a single fortran instruction are discussed and some short fortran programs which mix several such generators are described the aim is to provide methods for incorporating random number generators directly in fortran programs by means of a few in line instructions the advantages are speed avoiding linkage to and from a subroutine convenience and versatility anyone wishing to experiment with generators either using congruential generators by themselves or mixing several generators to provide a composite with potentially better statistical properties than the library generators currently available may wish to consider some of the simple fortran program discussed here
CACM	a note on a relevance estimate and its improvement in this paper the effect of iterating the improvement procedure is examined it is shown that applications of the improvement factor beyond the first time are ineffectual and that the factor is but a scale factor
CACM	the lrltran compiler extensive software problems confront an organization which possesses a number of different computers and which frequently acquires new ones to maintain cohesion a system must be developed written in a high level language which minimizes machine dependencies and isolates those which are necessary a language and a compiler for the language are discussed here the language called lrltran is a heavily augmented fortran the tree pass compiler makes use internally of a postfix polish notation pass i to pass ii and a tree representation referred to as a composite blocking table pass i to pass iii machine independent optimization occurs in pass ii and do loop and machine dependent optimization in pass iii
CACM	storage organization in programming systems the system of program and data representation that has been in use on the rice university computer for five years is described each logical entity in storage occupies a block of consecutive memory locations each block is labeled by a codeword and may contain a program a data vector or codewords which in turn label blocks to form arrays this storage arrangement is discussed with its realized advantages or programming systems simplicity of programmed addressing flexibility of data structures efficiency of memory utilization variability of system composition during execution means of linkage between programs and from programs to data and basis for storage protection the application of labeled blocks may be extended to areas of time sharing and multimedia storage control on the basis of experience at rice some ideas on such extensions are presented
CACM	automata formal languages abstract switching and computability in a ph d computer science program a number of courses are listed in the area describe as automata formal languages abstract switching and computability that might be available to a ph d student in computer science a brief catalog description of each course is applied and the role of each of the courses in the graduate program is discussed
CACM	a fast fourier transform algorithm for real valued series a new procedure is presented for calculating the complex discrete fourier transform of real valued time series this procedure is described for an example where the number of points in the series is an integral power of two this algorithm preserves the order and symmetry of the cooley turkey fast fourier transform algorithm while effecting the two to one reduction in computation and storage which can be achieved when the series is real also discussed are hardware and software implementations of the algorithm which perform only n 4 log2 n 2 complex multiply and add operations and which require only n real storage locations in analyzing each n point record
CACM	a general purpose display processing and tutorial system adept a display expedited processing and tutorial system is described this system was designed to improve man computer communications by employing a display unit to interleave tutoring with other computer operations such as simulation programming and information retrieval it is written in fortran iv g for the ibm system 360 model 40 and the ibm 2250 display unit under operating system 360 adept is a cataloged program that controls the standard operating system by terminating and rescheduling itself automatically relinquishing computer resources allocated to it and surrendering control to the operating system to perform other jobs it expands the power and flexibility of computer assisted instruction by making immediately available to students teachers and other users the full resources system cataloged programs of the operating system language processors and compilers simulation models mathematical solution techniques stored data and all other library and user programs can be incorporated into instructional material without reprogramming illustrations of the various applications are presented and their implications are discussed
CACM	easy english a language for information retrieval through a remote typewriter console easy english is a natural command language designed to simplify communication between man and machine through remote typewriter console it has been developed for retrieval of documents from a computerized data base the moore school information systems laboratory files requests are formulated in a standardized syntactical form examples of which are presented and this form is then transformed into an equivalent query expressed in the retrieval systems original symbolic command language which is briefly described operation of easy english is detailed by illustration of the transformations performed upon a sample request up to the point at which the request string is sent to the system a macro flowchart of easy english is included and an appendix provides the printout of a retrieval demonstration
CACM	the implementation of a basic system in a multiprogramming environment the implementation of a remote terminal basic system within the context of an existing multiprogramming computer system the burroughs b5500 is described this implementation combines a unique mixture of machine language and interpretive techniques with an incremental compiler
CACM	boolean matrix methods for the detection of simple precedence grammars a mechanical procedure is derived for determining whether a given context free phrase structure grammar is a simple precedence grammar this procedure consists of elementary operations on suitably defined boolean matrices application of the procedure to operator grammars is also given
CACM	ambiguity in limited entry decision tables the use of decision tables as a tool in systems analysis and for program specification is now becoming accepted rules on redundancy contradiction and completeness for limited entry tables were published in 1963 these are usually used for checking preceded if necessary by a conversion from extended to limited entry form processors which automatically translate tables to more conventional program usually base their diagnostic facilities on these rules in this paper it is suggested that these rules are unsatisfactory and that the important aspect of checking is to eliminate ambiguity from tables ambiguity is defined and discussed and a procedure for producing checked out decision tables is proposed the theoretical basis of the algorithm used is established the importance of well designed diagnostic facilities in decision table processors is emphasized
CACM	gan a system for generating and analyzing activity networks gan a system for generating activity networks is designed to save time in the preparation of activity networks and to deal conveniently with network programs a defining description of a programming language designed for generating activity network from a set of standard networks is presented also a general idea of a language for performing calculations on activity networks scheduling activity networks is given
CACM	computer synthesis of holograms for 3 d display optical and digital holography are reviewed the mathematical model and computational techniques of the authors digital holographic process are discussed and applications of computer holography are suggested computer holograms have been made of three dimensional objects which give faithful reconstructions even in white light a new approach based on point apertures for the image is discussed photographs of the images reconstructed from digital holograms are presented
CACM	netflow algorithm 248 h
CACM	netflow algorithm 248 h
CACM	calculation of a polynomial and its derivative values by horner scheme algorithm 337 c1
CACM	netflow algorithm 336 h
CACM	a comparison of the correlational behavior of random number generators for the ibm 360 hutchinson states that the new prime modulo multiplicative congruential pseudorandom generator attributed to d h lehmer has passed the usual statistical tests for random number generators it is here empirically shown that generators of this type can produce sequences whose autocorrelation functions up to lag 50 exhibit evidence of nonrandomness for many multiplicative constants an alternative generator proposed by tausworthe which uses irreducible polynomials over the field of characteristic two is shown to be free from this defect the applicability of these two generators to the ibm 360 is then discussed since computer word size can affect a generators statistical behavior the older mixed and simple congruential generators although extensively tested on computers having 36 or more bits per word may not be optimum generators for the ibm 360
CACM	numerical solution of a thin plate heat transfer problem the numerical solution of a system of linear equations resulting from a discrete approximation to a thin plate heat transfer problem is considered the slow convergence of point iterative methods is analyzed and shown to be caused by one of the boundary conditions the difficulty may be removed by a standard line iterative technique
CACM	gpl a truly general purpose language a truly general purpose programming language gpl is described which contains facilities for constructing within the language new data types as well as facilities for operations performed upon them the basic language is minimal in the sense that no basic element can be derived from the others with high efficiency in the object programs constructs like the algol 60 for statements and if statements are not basic they are special types of procedures new symbols underlined words in algol 60 are implicitly defined by usage in other declarations as part words are definable packed words are handled as easily as full words address variables pointers are included in full generality
CACM	an algorithm for the probability of the union of a large number of events an algorithm is presented which efficiently evaluates the probability for the union of n independent and not mutually exclusive events the problem is that of evaluating the sums of the products of all possible combinations of n variables in minimum time and storage space
CACM	plexus an on line system for modeling neural networks a description is presented of plexus a system which enables a user to construct and specify a neural network to analyze the output data produced by the network and to store and retrieve networks and data from a library the system operated entirely from a digital display unit interacts directly with the user and permits easy and rapid transitions between the various phases of the modeling process plexus is designed to complement neurophysiological research so that the systematic development of neural models can be coordinated with experimental work plexus networks are built up from components representing individual neurons external stimuli and interconnecting fibers each component being of a relatively detailed nature provision is also made for the use of experimental data as input to a network convenient means for specification and modification of a network and extensive error checking capabilities are provided data resulting from the simulation of a network may be analyzed by a variety of techniques ranging from examinations of the gross characteristics of the data to the determination of detailed statistical properties
CACM	an algorithm for identifying the ergodic subchains and transient states of a stochastic matrix an algorithm for identifying the ergodic subchains and transient states of a stochastic matrix is presented applications in markov renewal programming and in the construction of variable length codes are reviewed and an updating procedure for dealing with certain sequences of stochastic matrices is discussed computation times are investigated experimentally and compared with those of another recently propose method
CACM	graphical input output of nonstandard characters a system developed at harvard for graphically inputting and outputting nonstandard characters on a computer is printed in principle the system can deal with any orthography although at present it is limited to 4000 chinese characters and some mathematical symbols new characters can be added to the repertoire of the system by graphical input on a display scope text inputting is accomplished via a display scope or a rand tablet the organization and operation of the current system are described and a discussion of the relative merits of such a system is given illustrations of the computer input and output of chinese characters are included
CACM	a statistical model for console behavior in multiuser computers the ability of a computer system to communicate with the outside world efficiently is as important as its ability to perform computations efficiently it is quite difficult to characterize a particular user but rather easy to characterize the entire user community based on the properties of this community we have postulated a hypothetical virtual console no claim is made that a virtual console behaves like any actual console but the entire collection of virtual consoles models the collection of actual consoles using the model we answer questions like how many processes are suspended waiting for console input what is the maximum rate at which a process can execute what bounds can be set on overall buffer requirements answers to these and similar questions are needed in certain aspects of operating system design
CACM	experimental evaluation of information retrieval through a teletypewriter experiments designed to evaluate the capabilities of mechanized information retrieval systems with emphasis on interactive man machine language and on some of the mechanical and psychological limitations in their design were conducted at the moore school information systems laboratory the basic assumption of the research is that an information retrieval system that provides for man machine dialogue at a remote inquiry terminal should provide a searcher with many of the tools which would be available to him were he actually performing his search at a library or repository of documents factors involved in evaluation of such a system include ease of use learning time and effectiveness of actual retrieval three experiments and the conclusions resulting from them are detailed
CACM	peekabit computer offspring of punched card peekaboo for natural language searching the peekaboo idea from punched card information retrieval methods has been mated with the idea of superimposed punching to produce a programming technique which cuts computer run time in half on a test search of 33 000 subject index entries a search program using the device has been operational since late 1963 as an item is entered in the store an 18 byte mask is created from the items meaningful words using the inclusive or operation if at search time the logical product using the and operation of this mask and a similarly constructed question mask is not equal to the question mask then one or more question words are not present in the store item an equality is in conclusive the words of the store item must be unpacked and compared with question words the present store is made up of over 600 000 subject index entries estimated to average 60 characters each longer texts such as abstracts could be handled by multiple masks
CACM	synchronous signaling rates for data transmission proposed usa standard
CACM	commentary on mr mooers paper
CACM	accommodating standards and identification of programming languages the user public wants standardization and reliable identification of programming languages and related services one way of achieving these goals illustrated by the methods adopted for trac t 64 interactive language and its related family of languages oppressive rigidity usually associated with standardization is avoided by a new accommodation technique accessible to the user to allow local variations with the language explicit standardization of the language is undertaken at the organizational source of the language use of the organizational trademark trac on the published standards and services relying upon them provides a reliable public identification these methods can be usefully applied to other programming languages and computer services
CACM	minimum excess cost curve algorithm 217 h
CACM	a set of basic input output procedures algorithm 335 15 by means of the primitives in symbol outsymbol and length as requested by this journals algorithms policy comm acm 10 nov 67 729 a basic set of input output procedures is defined aiming at quality and flexibility outreal for instance is written as a derived procedure it outputs using the fixed point or the floating point representation and rounds properly variants can easily be written because of the explicit call of the procedures decompose integer and decompose real the highly recommended practice of echoing input is made easy with one subset of derived procedures ioi ior iob ioa the documentation of output in the form of equivalent algol statements is also provided when use is made of the subset oti otr otb ota the berkeley style of providing information on the form of output using prior calls of procedures such as real format is defined a use of the parameter outchannel to provide information for simultaneous output to several channels is suggested interrelationship between the declared procedures is furnished in tabular form
CACM	champ character manipulation procedures a new programming language facility for symbol manipulation is described string procedures may be declared and called in a standard algol context algol procedures can in turn be called by string procedures so that numeric and symbolic processes may conveniently be programmed together concatenation and a variant of snobols pattern matching make up a set of primitive commands these are assembled together into conditional expressions which are to be used to provide alternative computational patterns arrays of strings are processed using quantifiers the class of things which may be assigned to an identifier can be restricted by a procedure expressed in the notation the language facilities have been implemented in the algol compiler for the burroughs b5500
CACM	generation of positive test matrices with known positive spectra sufficient conditions are given for a real matrix to be similar to a positive matrix this result is used to construct a similarity transformation which when applied to a particular upper triangular matrix yields a positive matrix with a preassigned positive spectrum
CACM	a note on the efficiency of a lisp computation in a paged machine the problem of the use of two levels of storage for programs is explored in the context of a lisp system which uses core memory as a buffer for a large virtual memory stored on a drum details of timing are given for one particular problem
CACM	a modification of efroymsons technique for stepwise regression analysis the computational technique conventionally used for stepwise multiple linear regression requires the storage of an n x n matrix of data when the number of variables n is large this requirement taxes the storage capacity of presently used machinery the near symmetry of the matrices involved permits a modification requiring only half the storage and computations of the conventional algorithm and this additional storage allows the analysis of problems containing more variables alternatively it permits the analysis of problems containing the same number of variables but with all computations performed in double precision
CACM	asp a ring implemented associative structure package asp is a general purpose associative data structure package in which an arbitrary number of data items and an arbitrary number of the relationships between these data items may be represented a special picture language is described which has proved very useful for drawing asp structures on paper asp structures are built and manipulated by means of a series of macro calls which are outlined in the appendix emphasis is on the philosophy of the system rather than a particular implementation though sufficient information is included to enable the reader to produce his own implementation of asp
CACM	when your computer needs a lawyer possible liability for negligence for other torts such as slander of credit and for liability under theories of express or implied warranty guarantees are discussed and legal complications are explained so that users operators owners and leasors of computers may be alerted to potential legal problems focus is also on trouble spots in contracting for data processing services in automating record keeping operations in deciding whether or not to automate certain operations and in complying with statutes and regulation relating to record keeping information is given on patents copyrights and trade secret protection for programs and the problem of using copyrighted material in information storage and retrieval systems including the pending copyright and patent revision bills
CACM	recovery of disk contents after system failure a method is discussed by which after a system malfunction the contents of disk files can be restored to their status at the time of the failure
CACM	on overcoming high priority paralysis in multiprogramming systems a case his tory high priority paralysis is the degradation that can occur in multiprogramming systems when scheduling is based primarily on preassigned priorities it can be alleviated by modifying the scheduling algorithm to maximize the number of programs active at one time the case his tory given in this paper indicates two general methods by which simultaneity can be increased possible refinements in the scheduling algorithm for future improvements are considered briefly
CACM	procedure for the normal distribution algorithm 272 s15
CACM	direct search algorithm 178 e4
CACM	normal random deviates algorithm 334 g5
CACM	generating prime implicants via ternary encoding and decimal arithmetic decimal arithmetic ternary encoding of cubes and topological considerations are used in an algorithm to obtain the extremals and prime implicants of boolean functions the algorithm which has been programmed in the fortran language generally requires less memory than other minimization procedures and treats dont care terms in an efficient manner
CACM	logical arithmetic on computers with twos complement binary arithmetic algorithms are presented for multiplication and division of unsigned integer operands in which the digits normally reserved for signs participate as significant arithmetic digits with positive weight
CACM	a methodology for calculating and optimizing real time system performance the continually increasing size complexity number of types and cost of data processing systems are causing serious re examination within government and industry of the criteria for and methods of calculating and optimizing data processing system cost and performance real time data processing systems as typified by the automated airline reservation system are discussed in this paper criteria for evaluating performance are described a methodology for calculating and optimizing is outlined and the method is illustrated by carrying out a portion of the performance calculation and the optimization of a drum oriented message switching system
CACM	masters level computer science curricula the results of a survey of the course work done by masters degree candidates at 25 us universities are presented and some general comments concerning the emphasis of these programs are given
CACM	determination of the intersection points of two plane curves by means of differential equations a new method is proposed to calculate the intersection points of two plane curves the theory of singular points off a system of two differential equations is used in developing the method the intersection point to be determined is identified with such a singular point and appropriate modifications are applied to the system to ensure that the singular point be stable i e all integrals which start in the neighborhood of the singular point will always approach this point if the integral parameter tends to infinity in addition a method is described for systematically searching for all intersection points in a prescribed rectangular area
CACM	methods of convergence improvement for some improper integrals in the numerical integration of an improper integral of the first kind it is customary to truncate the integral when the change yielded by the last iteration is less than some predetermined constant the efficiency of such integration schemes can often be improved by use of recent advances in the theory of nonlinear transformations however for several important integrals e g integrals whose integrands are rational polynomials these transformations fail to yield much improvement in this paper several methods of convergence improvement are developed which greatly improve convergence of some improper integrals including the integrals of rational polynomials
CACM	computer construction of project networks project networks are used in pert and cpm an algorithm is given for constructing project networks directly from the project precedence relations the algorithm creates dummy activities and topologically orders the arcs and nodes the number of nodes created is minimal for the given precedence relations it has been experimentally programmed in fortran ii for the ibm 7094
CACM	a generalized partial pass block sort the design of a partial pass block sort with arbitrary range of key and number of work files is described the design is a generalization of the partial pass column sort by ashenhurst and the amphisbaenic sort by nagler the power of the sort is tabulated for various sizes of input file and number of work files consideration is given to the problem of combining a block sort with internal sorts and to the best use of direct access storage devices
CACM	a simple proof of lewins ordered retrieval theorem for associative memories an efficient method of ordered retrieval of binary words from an associative memory as described by lewin is based on the use of special readout circuits which indicate the digit values present in the individual digit columns of the memory thus the circuits indicate whether the individual digit columns contain digits of both values or of only one value or contain no digits at all i e that the memory is empty the use of these circuits which in this paper are termed column value indicators reduces considerably the number of memory accesses necessary to retrieve in order a number of distinct words from the memory lewin proves that for the readout by the described method of m distinct binary words 2m   1 memory accesses are necessary thus he proves that the number of necessary memory accesses of his method unlike those of other methods is independent of the word length in this paper a very simple proof of this theorem derived from some elementary aspects of the structure of sets of binary numbers is presented
CACM	preliminary investigation of techniques for automated reading of unformatted text methods for converting unstructured printed material into computer code are experimentally investigated an operator controlled mode depending on human demarcation of the various regions of the page for guiding the scanner is implemented by means of a joystick and a crt display this mode for which some performance figures are obtained is thought to be suitable for processing very complicated material such as technical journals for simpler material for instance the claims sections of patents and in applications where the utmost accuracy is not necessary an unsupervised mode is advocated here the textual portions of the page are located during a rapid prescan by a rudimentary form of frequency analysis these areas are then rescanned at a higher resolution suitable for character recognition error rates of the order of 0 1 percent are obtained in a simple problem involving photographs of telephone company meter boards other matters related to the design of a general purpose page reader such as the segmentation of printed text the possibility of time sharing the scanner interactive man machine operation and the facsimile reproduction of illustrations are discussed
CACM	one way of estimating frequencies of jumps in a program for the segmentation of a program it is useful to have a reasonable estimation of the values of s ij where s ij is the mean value of the number of jumps from the i th instruction on to the j th instruction in the run time in the cases where the s ij are estimated directly the structure of the whole program must be generally taken into account therefore it is very difficult for the programmer and or the translator to obtain a good estimation of the s ij it is easier to estimate not s ij but the quantities p ij s ij c i sum s ij j 1 n where c i is an arbitrary positive constant for each i although the p ij are for each i proportional to s ij the estimation of p ij is easier because we must estimate only the probabilities of events where instruction i is executed after instruction i i this estimation can often be done without considering the structure of the whole program in the first part of the paper using the theory of the markov chains an algorithm for the computation of the s ij from the p ij is found and some ways of obtaining estimates of the p ij are given in the second part a variant of this algorithm is derived avoiding the necessity of computation involving large matrices
CACM	further experimental data on the behavior of programs in a paging environment results are summarized from an empirical study directed at the measurement of program operating behavior in those multiprogramming systems in which programs are organized into fixed length pages the data collected from the interpretive execution of a number of paged programs are used to describe the frequency of page faults i e the frequency of those instants at which an executing program requires a page of data or instructions not in main core memory these data are used also for the evaluation of page replacement algorithms and for assessing the effects on performance of changes in the amount of storage allocated to executing programs
CACM	minit algorithm for linear programming algorithm 333 h
CACM	jacobi polynomials algorithm 332 s22
CACM	gaussian quadrature formulas algorithm 331 d1
CACM	factorial analysis of variance algorithm 330 g1
CACM	distribution of indistinguishable objects into distinguishable slots algorithm g6
CACM	chebyshev solution to an overdetermined linear system algorithm 328 f4
CACM	a futures market in computer time an auction method is described for allocating computer time that allows the price of computer time to fluctuate with the demand and the relative priority of users to be controlled so that more important projects get better access this auction is free of the periodic fluctuation in computer use often associated with monthly time allocation schemes
CACM	heading format for data transmission a usaai tutorial    standards
CACM	a global parser for context free phrase structure grammars
CACM	writing an outline debugging program for the experienced user presently available online debugging routines are often unsatisfactory for the experienced user because they require unnecessarily rigid and complicated typing formats make it difficult for the user to correct typing errors and consume excessive memory with intricate features in a debugging program it is of prime importance that the program be simple flexible and highly efficient to use communication between the user and the debugging program can be improved by using certain techniques applicable to most online debugging programs these techniques are presented and are illustrated by their use in opak octal package a debugging program coded for the pdp 5 8 and the sds 930 the compromise between economy of utility program core storage and incorporation of elegant debugging features is discussed
CACM	regular expression search algorithm a method for locating specific character strings embedded in character text is described and an implementation of this method in the form of a compiler is discussed the compiler accepts a regular expression as source language and produces an ibm 7094 program as object language the object program then accepts the text to be searched as input and produces a signal every time an embedded string in the text matches the given regular expression examples problems and solution are also presented
CACM	an inexpensive braille terminal device the active use of time shared facilities for blind programmers requires a braille terminal system details are given for the construction of a brailler from a model 33 teletype by modifying the print head and increasing the resiliency of the platen a description of the programming needed to drive the brailler is presented
CACM	brad the brookhaven raster display a multiconsole computer display system has been designed that provides very rich displays at low unit cost each brad brookhaven raster display console can plot tens of thousands of points or up to 4000 characters at 30 frames per second after an initial display system investment of 50 000 each display with teletype costs less than 3 000 the technique employed is that of programmatically generating a binary image of the desired display in a computer the image is written on a rotating drum memory independent read heads continuously display the picture which is generated by swept horizontal lines a standard tv monitor serves as the display device the technique has two drawbacks a computer must compute any image to be displayed also the pointing interaction is more difficult this is because the pointing function gives only the coordinates of the point on the screen the inverse of the map generation process is required to calculate the coordinates of the point on the screen the inverse of the map generation process is required to calculate the coordinates at the selected point in the input space
CACM	on the design of display processors the flexibility and power needed in the data channel for a computer display are considered to work efficiently such a channel must have a sufficient number of instructions that it is best understood as a small processor rather than a powerful channel as it was found that successive improvements to the display processor design lie on a circular path by making improvements one can return to the original simple design plus one new general purpose computer for each trip around the degree of physical separation between display and parent computer is a key factor in display processor design
CACM	reliable full duplex file transmission over half duplex telephone lines a field proven scheme for achieving reliable duplex transmission over a half duplex communication line is presented and to demonstrate the difficulty of the problem another similar scheme which is only slightly unreliable is also presented a flowchart for the reliable scheme and some interesting examples are given
CACM	stable numerical methods for obtaining the chebyshev solution to an overdetermined system of equations an implementation of stiefels exchange algorithm for determining a chebyshev solution to an overdetermined system of linear equations is presented that uses gaussian lu decomposition with row interchanges the implementation is computationally more stable than those usually given in the literature a generalization of stiefels algorithm is developed which permits the occasional exchange of two equations simultaneously
CACM	a position paper on computing and communications the effective operation of free enterprise in creating the envisioned information service industry is dependent upon three accomplishments 1 the restructuring of our information processing industry so that a clear division of costs is made among computing communications and the development of information services 2 the wide use of multiaccess system concepts so that information services may share in the use of computer installations and so that the cost of their construction is reasonable and 3 the development of public message switched communications services so that adequate provisions are made for information security
CACM	protection in an information processing utility one of the critical problems in the design of an information processing utility that permits flexible sharing of user information is privacy one solution for this problem is discussed
CACM	three criteria for designing computing systems to facilitate debugging the designer of a computing system should adopt explicit criteria for accepting or rejecting proposed system features three possible criteria of this kind are input recordability input specifiability and asynchronous reproducibility of output these criteria imply that a user can if he desires either know or control all the influences affecting the content and extent of his computers output to define the scope of the criteria the notion of an abstract machine of a programming language and the notion of a virtual computer are explained examples of applications of the criteria concern the reading of a time of day clock the synchronization of parallel processes protection in multiprogrammed systems and the assignment of capability indexes
CACM	a scheduling philosophy for multiprocessing systems a collection of basic ideas is presented which have been evolved by various workers over the past four years to provide a suitable framework for the design and analysis of multiprocessing systems the notions of process and state vector are discussed and the nature of basic operations on processes is considered some of the connections between processes and protection are analyzed a very general approach to priority oriented scheduling is described and its relationship to conventional interrupt systems is explained some aspects of time oriented scheduling are considered the implementation of the scheduling mechanism is analyzed in detail and the feasibility of embodying it in hardware established finally several methods for interlocking the execution of independent processes are presented and compared
CACM	the structure of the the  multiprogramming system a multiprogramming system is described in which all activities are divided over a number of sequential processes these sequential processes are placed at various hierarchical levels in each of which one or more independent abstractions have been implemented the hierarchical structure proved to be vital for the verification of the logical soundness of the design and the correctness of its implementation
CACM	considerations in the design of a multiple computer system with extended core storage the use of large quantities of addressable but not executable fast random access memory to heighten the multiprogramming performance of a multicomputer system is discussed the general design of the hardware arrangement and the software components and functions of such a system are based on a planned configuration of dual cdc 6600s that share one million words of extended core storage in the generalization of such a design special emphasis is placed on estimating expected gains when compared with the traditional configuration of separate and independent computers without extended core storage an observation is made on the use of conventional slower speed random access storage devices in place of the faster memory
CACM	the working set model for program behavior probably the most basic reason behind the absence of a general treatment of resource allocation in modern computer systems is an adequate model for program behavior in this paper a new model the working set model is developed the working set of pages associated with a process defined to be the collection of its most recently used pages provides knowledge vital to the dynamic management of paged memories process and working set are shown to be manifestations of the same ongoing computational activity then processor demand and memory demand are defined and resource allocation is formulated as the problem of balancing demands against available equipment
CACM	resource management for a medium scale time sharing operating system task scheduling and resource balancing for a medium size virtual memory paging machine are discussed in relation to a combined batch processing and time sharing environment a synopsis is given of the task scheduling and paging algorithms that were implemented and the results of comparative simulation are given by tracing the development of the algorithms through six predecessor versions throughout the discussion particular emphasis is placed on balancing the system performance relative to the characteristics of all the system resources simulation results relative to alternate hardware characteristics and the effects of program mix and loading variations are also presented
CACM	virtual memory processes and sharing in multics some basic concepts involved in the design of the multics operating system are introduced multics concepts of processes address space and virtual memory are defined and the use of paging and segmentation is explained the means by which users may share procedures and data is discussed and the mechanism by which symbolic references are dynamically transformed into virtual machine addresses is described in detail
CACM	dynamic storage allocation systems in many recent computer system designs hardware facilities have been provided for easing the problems of storage allocation a method of characterizing dynamic storage allocation systems according to the functional capabilities provided and the underlying techniques used is presented the basic purpose of the paper is to provide a useful perspective from which the utility of various hardware facilities may be assessed a brief survey of storage allocation facilities in several representative computer systems is included as an appendix
CACM	proceedings of the acm symposium on operating system principles
CACM	hollerith punched card code proposed usa standard
CACM	data code for calendar date for machine to machine data interchange proposed usa standard
CACM	symmetric polynomials algorithm 305 c1
CACM	transportation problem algorithm 293 h
CACM	normal curve integral algorithm 304 s15
CACM	chi squared integral algorithm 299 s15
CACM	dilogarithm algorithm 327 s22
CACM	roots of low order polynomial equations algorithm 326 c2
CACM	panel discussion on computer appreciation session 19 of the acm 20 th anniversary conference on august 31 1967 was entitled education design experiments and computer appreciation its second half consisted of a panel discussion on computer appreciation organized and chaired by elliot i organick the four panelists were charles h davidson bernard a galler richard w hamming and alan j perlis after making prepared statements the panelists were joined in discussion by andries van dam and arthur b kohn who had presented papers in the first half this is a transcript of the panel discussion condensed by dr organick and edited by him and the panelists some remarks referred to papers by van dam and kahn or to the discussion during the first half of the session pertinent papers are included in the references
CACM	expenditures sources of funds and utilization of digital computers for research and instruction in higher education 1964 65 with projections for 1968 69 the southern regional education board published a complete report on a survey it conducted to determine the funding and characterize the utilization of computers used for research and instruction in institutions of higher education in the united states the sampling survey is described and the estimates for this total population are presented
CACM	quasilinearization and the estimation of differential operators from eigenvalues given a linear ordinary differential operator containing several unknown constants and a number of its eigenvalues the values of the unknown constants are estimated a precise formulation is provided and an effective numerical procedure for solution is indicated the results of some computational experiments are given
CACM	a general purpose graphic language interactive use of computers with graphic terminals will permit many new problems to be solved using machines in order to handle a variety of applications it is expedient to develop a general purpose graphic language that is useful on a number of graphic devices a system has been designed to produce such a language quickly and cheaply a model graphic language which has been developed with the system is presented
CACM	a global parser for context free phrase structure grammars an algorithm for analyzing any context free phrase structure grammar and for generating a program which can then parse any sentence in the language or indicate that the given sentence is invalid is described the parser is of the top to bottom type and is recursive a number of heuristic procedures whose purpose is to shorten the basic algorithm by quickly ascertaining that certain substrings of the input sentence cannot correspond to the target nonterminal symbols are included both the generating algorithm and the parser have been implemented in rca snobol and have been tested successfully on a number of artificial grammars and on a subset of algol a number of the routines for extracting data about a grammar such as minimum lengths of n derivable strings and possible prefixes are given and may be of interest apart from their application in this particular context
CACM	the expanding world of computers the onward sweep of automatic processing of information is impeded by nine principal barriers geography cost problem complexity man machine communication inadequate sensors lack of understanding distance time and size the main incentive for breaching these barriers is the universal need for processing information ever more urgent as the greater part of human work activity changes from production to service computer developments in hardware programming time sharing education data communication and displays are judged by how effectively they remove these barriers and their barrier smashing potentialities indicate continued rapid expansion problem oriented languages are particularly effective over the entire front online computers and time sharing also rate high by this measure education and increased understanding are basic to all progress with the computer this complex but powerful tool is the most important one available to governments and scientists to use in studying the problems being created by the population explosion and in analyzing possible solutions
CACM	rules of ethics in information processing the background and motivation for the adoption by the acm council on november 11 1966 of a set of guidelines for professional conduct in information processing are described a brief his tory is given of ethical codes in other professions some reasons for and against adoption of ethical rules are considered and several sections of the acm guidelines are analyzed the purpose is to inform about this important aspect of our profession as well as to stimulate thought and interest
CACM	curriculum 68    recommendations for academic programs in computer science    a report of the acm curriculum committee on computer science this report contains recommendations on academic programs in computer science which were developed by the acm curriculum committee on computer science a classification of the subject areas contained in computer science is presented and twenty two courses in these areas are described prerequisites catalog descriptions detailed outlines and annotated bibliographies for these courses are included specific recommendations which have evolved from the committees 1965 preliminary recommendations are given for undergraduate programs graduate programs in computer science are discussed and some recommendations are presented for the development of masters degree programs ways of developing guidelines for doctoral programs are discussed but no specific recommendations are made the importance of service courses minors and continuing education in computer science is emphasized attention is given to the organization staff requirements computer resources and other facilities needed to implement computer science educational programs
CACM	usascsocr dual case keyboard arrangement proposed usa standard
CACM	general purpose alphanumeric keyboard arrangement for information interchange proposed usa standard
CACM	program overlay techniques the general features of program overlay systems are described three main types    automatic semiautomatic and nonautomatic    are classified and the programming techniques are explained as a function of machine hardware and other system features the implementation of semiautomatic overlay facility in a multiprogrammed system on the cdc 6600 is described in detail with special reference to real time applications
CACM	adjustment of the inverse of a symmetric matrix when two symmetric elements are changed algorithm 325 f1
CACM	maxflow algorithm 324 h
CACM	generation of permutations in lexicographic order algorithm 323 g6
CACM	f distribution algorithm 322 s14
CACM	t test probabilities algorithm s14
CACM	harmonic analysis for symmetrically distributed data algorithm 320 c6
CACM	translator writing systems a critical review of recent efforts to automate the writing of translators of programming languages is presented the formal study of syntax and its application to translator writing are discussed in section ii various approaches to automating the post syntactic semantic aspects of translator writing are discussed in section iii and several related topics in section iv
CACM	a numerical integration formula useful in fourier analysis a numerical integration formula is presented which uses unequal sampling intervals the intervals are equally spaced on a log scale such a formulation is useful in fourier analysis to improve accuracy and ease of usage a complete set of formulas for numerical fourier analysis is given
CACM	in and out conversions byan in and out conversion we mean that a floating point number in one base is converted into a floating point number in another base and then converted back to a floating point number in the original base for all combinations of rounding and truncation conversions the question is considered of how many significant digits are needed in the intermediate base to allow such in and out conversions to return the original number when possible or at least significant digit
CACM	practical error coefficients for estimating quadrature errors for analytic functions all published error coefficients for estimating quadrature errors for analytic functions were computed on the assumption that the quadrature rule was exact for polynomials up to a given degree since these rules use rounded values for the abscissas and weights and since the true values of the integrals of some of the polynomials in question have an infinite binary expression the quadrature rule is not exact hence these errors must be taken into consideration in computing practical error coefficients
CACM	scatter storage techniques scatter storage techniques as a method for implementing the symbol tables of assemblers and compilers are reviewed and a number of ways of using them more effectively are presented many of the most useful variants of the techniques are documented
CACM	an improved hash code for scatter storage introduced is a hash coding method based on fixed point division rather than multiplication or logical operations this new method allows the hash table to have almost any length also a new method of handling collisions is discussed known as quadratic search this method is faster than random search and free from the clusters that build up with a linear search
CACM	use of transition matrices in compiling an algorithms is described which constructs from a suitable bnf grammar an efficient left right recognizer for sentences of the corresponding language the type of recognizer used in a number of compilers operates with a pushdown stack and with a transition matrix two examples illustrate how such recognizers may be used effectively for other purposes besides the usual syntax checking
CACM	toward a general processor for programming languages many efforts have been made to develop a better way of implementing a higher level programming language than by the construction of a whole new compiler but so far none has proved generally satisfactory in this paper it is contended that a programming language is best described functionally as a body of macro instructions and that the macro call constitutes a canonical form in terms of which a programming notation may be described a supporting discussion of the logical and his torical role of the macro instruction is presented also discussed are the conflict between machine independence and object program efficiency and the question of where the greatest difficulties lie in compiler construction
CACM	logarithm of gamma function algorithm 291 s14
CACM	mullers method for finding roots of an arbitrary function algorithm 196 c5
CACM	triangular factors of modified matrices algorithm 319 f1
CACM	exploratory experimental studies comparing online and off line programming performance two exploratory experiments were conducted at system development corporation to compare debugging performance of programmers working under conditions of on line and off line access to a computer these are the first known studies that measure programmers performance under controlled conditions for standard tasks statistically significant results of both experiments indicated faster debugging under online conditions but perhaps the most important practical finding involves the striking individual differences in programmer performance methodological problems encountered in designing and conducting these experiments are described limitations of the findings are pointed out hypotheses are presented to account for results and suggestions are made for further research
CACM	presentation of alphameric characters for information processing proposed american national standard
CACM	a fast random number generator for ibm 360
CACM	optimal code for serial and parallel computation
CACM	index by subject to algorithms 1969
CACM	solution of linear programs in 0 1 algorithm 341 h
CACM	coulomb wave functions algorithm 300 s22
CACM	elementary functions by continued fractions algorithm 229 b1
CACM	psif algorithm 147 s14
CACM	analysis of variance for balanced experiments algorithm 367 g2
CACM	regression using certain direct product matrices algorithm 366 g2
CACM	complex root finding algorithm 365 c5
CACM	coloring polygonal regions algorithm 364 z
CACM	productivity of multiprogrammed computers progress in developing an analytic prediction method multiprogramming as it is discussed here is a mode of computer operation in which two or more programs are concurrently in processor memory and proceeding each using the same central processor unit cpu and input output i o channels these programs are actually proceeding intermittently and singly according to eligibility readiness to proceed and priority it is useful to be able to represent them as proceeding continuously and simultaneously each at an effective rate which may be a fraction of that which it would enjoy in the absence of the other programs the effective progress rate of each program is sensitive to many detailed characteristics of itself and its co residents and simulation has been the best available method of predicting it this paper presents the results of progress in developing an alternative to simulation a simulation tested iterative computation of these rates under certain situations the algorithm is sensitive to most of the factors that control the phenomenon including nonquantitative or topological features of the programs structures
CACM	on the downhill method the downhill method is a numerical method for solving complex equations f z 0 on which the only restriction is that the function w f z must be analytical an introduction to this method is given and a critical review of relating literature is presented although in theory the method always converges it is shown that a fundamental dilemma exists which may cause a breakdown in practical applications to avoid this difficulty and to improve the rate of convergence toward a root some modifications of the original method are proposed and a program fortran based on the modified method is given in algorithm 365 some numerical examples are included
CACM	optimization of expressions in fortran a method of optimizing the computation of arithmetic and indexing expressions of a fortran program is presented the method is based on a linear analysis of the definition points of the variables and the branching and do loop structure of the program the objectives of the processing are 1 to eliminate redundant calculations when references are made to common subexpression values 2 to remove invariant calculations from do loops 3 to efficiently compute subscripts containing do iteration variables and 4 to provide efficient index register usage the method presented requires at least a three pass compiler the second of which is scanned backward it has been used in the development of several fortran compilers that have proved to produce excellent object code without significantly reducing the compilation speed
CACM	advanced cryptographic techniques for computers cryptographic techniques which can be used to maintain the confidentiality of information processed by computers are dealt with special emphasis is paid to the unique characteristics of computer files that make many cryptographic methods of little use relative security costs and preferred methods are included in this paper
CACM	numerical analysis in a ph d computer science program numerical analysis is the study of methods and procedures used to obtain approximate solutions to mathematical problems much of the emphasis is on scientific calculation the difficulties of education in such a broad area center around the question of background and emphasis the numerical analysis program in the computer science department should emphasize an awareness of the problems of computer implementation and experimental procedures nevertheless there is a need for a solid background in applied mathematics
CACM	is automatic folding of programs efficient enough to displace manual the operation of folding a program into the available memory is discussed measurements by brown et al and by nelson on an automatic folding mechanism of simple design a demand paging unit built at the ibm research center by belady nelson oneil and others permitting its quality to be compared with that of manual folding are discussed and it is shown that given some care in use the unit performs satisfactorily under the conditions tested even though it is operating across a memory to storage interface with a very large speed difference the disadvantages of prefolding which is required when the folding is manual are examined and a number of the important troubles which beset computing today are shown to arise from or be aggravated by this source it is concluded that a folding mechanism will probably become a normal part of most computing systems
CACM	a case study in programming for parallel processors an affirmative partial answer is provided to the question of whether it is possible to program parallel processor computing systems to efficiently decrease execution time for useful problems parallel processor systems are multiprocessor systems in which several of the processors can simultaneously execute separate tasks of a single job thus cooperating to decrease the solution time of a computational problem the processors have independent instruction counters meaning that each processor executes its own task program relatively independently of the other processors communication between cooperating processors is by means of data in storage shared by all processors a program for the determination of the distribution of current in an electrical network was written for a parallel processor computing system and execution of this program was simulated the data gathered from simulation runs demonstrate the efficient solution of this problem typical of a large class of important problems it is shown that with proper programming solution time when n processors are applied approaches 1 n times the solution time for a single processor while improper programming can actually lead to an increase of solution time with the number of processors stability of the method of solution was also investigated
CACM	more on fortran random number generators
CACM	generation of permutations in pseudo lexicographic order algorithm 308 g6
CACM	direct search algorithm 178 e4
CACM	direct search algorithm 178 e4
CACM	generalized least squares fit by orthogonal polynomials algorithm 296 e2
CACM	computation of fourier coefficients algorithm 255 c6
CACM	associated legendre functions of the first kind for real or imaginary arguments algorithm 47 s16
CACM	complex error function algorithm 363 s15
CACM	generation of random permutations algorithm 362 g6
CACM	permanent function of a square matrix i and ii algorithm 361 g6
CACM	shortest path forest with topological ordering algorithm h
CACM	factorial analysis of variance algorithm g1
CACM	aparel a parse request language aparel is described this language is an extension to an algorithmic language pl i that provides the pattern matching capabilities normally found only in special purpose languages such as snobol4 and tmg this capability is provided through parse requests stated in a bnf like format these parse requests form their own programming language with special sequencing rules upon successfully completing a parse request an associated piece of pl i code is executed this code has available for use as normal pl i strings the various pieces at all levels of the parse it also has available as normal pl i variables the information concerning which of the various alternatives were successful convenient facilities for multiple input output streams the initiation of sequences of parse requests as a subroutine and parse time semantic checks are also included aparel has proven convenient in building a powerful syntax and function macro system an algebraic language preprocessor debugging system an on line command parser a translator for dataless programming and as a general string manipulator
CACM	a practical method for constructing lr k processors a practical method for constructing lr k processors is developed these processors are capable of recognizing and parsing an input during a single no backup scan in a number of steps equal to the length of the input plus the number of steps in its derivation the technique presented here is based on the original method described by knuth but decreases both the effort required to construct the processor and the size of the processor produced this procedure involves partitioning the given grammar into a number of smaller parts if an lr k processor can be constructed for each part using knuths algorithm and if certain conditions relating these individual processors are satisfied then an lr k processor for the entire grammar can be constructed for them using this procedure an lr 1 parser for algol has been obtained
CACM	a lisp garbage collector for virtual memory computer systems in this paper a garbage collection algorithm for list processing systems which operate within very large virtual memories is described the object of the algorithm is more the compaction of active storage than the discovery of free storage because free storage is never really exhausted the decision to garbage collect is not easily made therefore various criteria of this decision are discussed
CACM	performance monitoring in a time sharing system a software measurement facility which is part of a general purpose time sharing system is described the date collection facility dcf has been implemented in the michigan terminal system mts for the system 360 model 67 it exists for the purpose of monitoring operating system and user program behavior and performance the overall structure of mts is outlined in order to explain the implementation of the dcf events in the system are identified and recorded from within the supervisor and dumped to magnetic tape by an auxiliary program for off line processing events in user programs which are unrelated to system actions are recorded with a supervisor call the time of occurrence of each event is accurately recorded and data items are further identified by job and type the overhead associated with data collection and its interference with normal jobs is carefully analyzed and both are shown to be minimal several examples are given of information obtained with the facility and of applications in which it has been useful some general guidelines are offered for the construction of future monitoring programs
CACM	synchronization in a parallel accessed data base the following problem is considered given a data base which can be manipulated simultaneously by more than one process what are the rules for synchronization which will maximize the amount of parallel activity allowed it is assumed that the data base can be represented as a graph an example of such a data base is a hierarchy of directories for an on line file system methods for synchronization of processes are examined their validity is discussed and their performance compared
CACM	an interactive graphical display monitor in a batch processing environment with remote entry a graphic monitor program is described it was developed at carnegie mellon university for the cdc g21 computer which is a general purpose batch processing system with remote entry the existing g21 system and the graphics hardware are described the graphic monitor is a resident auxiliary monitor which provides comprehensive managerial capability over the graphical system in response to commands from the human user it also will respond to commands from a user program through a similar interface where routine calls take the place of manual actions thus the human and program can interact on a symmetrical and equal basis through the medium of the graphic monitor the choice made in designing the graphic monitor given the constraints of the existing hardware and computer system are discussed the structure of the monitor program and the human and program interfaces are described there is also a transient swapping version with a small resident part and provision for swapped used submonitors
CACM	retrieval times for a packed direct access inverted file
CACM	a comment on optimal tree structures
CACM	minimax logarithmic error
CACM	an ambiguity in the description of algol 60
CACM	an axiomatic basis for computer programming in this paper an attempt is made to explore the logical foundations of computer programming by use of techniques which were first applied in the study of geometry and have later been extended to other branches of mathematics this involves the elucidation of sets of axioms and rules of inference which can be used in proofs of the properties of computer programs examples are given of such axioms and rules and a formal proof of a simple theorem is displayed finally it is argued that important advantages both theoretical and practical may follow from a pursuance of these topics
CACM	the iitran programming language the iitran language developed to be used by students and its important important features are described iitran is a procedure oriented language with a one level block structure and a variety of data types several novel and powerful features are included a discussion of design principles to be followed in a student language is given
CACM	a new method for determining linear precedence functions for precedence grammars the precedence relations of a precedence grammar can be precisely described by a two dimensional precedence matrix often the information in the matrix can be represented more concisely by a pair of vectors called linear precedence functions a new algorithm is presented for obtaining the linear precedence functions when given the precedence matrix this algorithm is shown to possess several computational advantages
CACM	an algol convolution procedure based on the fast fourier transform algorithm 345 c6
CACM	normal curve integral algorithm 304 s15
CACM	singular value decomposition of a complex matrix algorithm 358 f1 4 5
CACM	an efficient prime number generator algorithm 357 a1
CACM	a prime number generator using the treesort principle algorithm 356 a1
CACM	an algorithm for generating ising configurations algorithm 355 z
CACM	the choice of base a digital computer is considered whose memory words are composed on n r state devices plus two sign bits two state devices the choice of base b for the internal representation of floating point numbers on such a computer is discussed it is shown that in a certain sense b r is best
CACM	a modular computer sharing system an alternative approach to the design and organization of a general purpose interactive multiterminal computing system is presented the system organization described is a conceptually simple arrangement of a bank of interchangeable computers each of which is a memory processor pair that are assigned to process terminal jobs as they arrive one of the computers serves as the master or control computer and supervises the collection and distribution of messages from and to the remote terminals in the simplest form there is a disk drive for each connected terminal a crosspoint switching network allows any such disk drive to be connected to any computer thus while each active terminal user occupies a dedicated disk drive he may share the computer with many other terminal users in a simple manner the ratio of users to computers is dependent on both the size and power of the machines used and the computation requirements of the particular mix of users this system organization is inherently a simpler and therefore more reliable approach to time sharing computers and has the potential of a highly available system at relatively low cost economic configurations are possible for a range of systems sizes that span at least one order of magnitude finally problem programs developed by remote terminal users can be run on a dedicated batch system if compatible computers are used
CACM	loader standardization for overlay programs the overlay capability is described for four of the third generation computer systems cdc 6000 ge 635 ibm 360 and univac 1108 a critique of the first three systems is based on actual experience with a large overlaid trajectory simulation program a short history and description of this program is presented a standardization of minimum capabilities for loaders is recommended so that programs which must operate under more than one computer system may be easily converted and maintained a proposal that overlay software incorporates a memory occupation specification concept instead of the conditional tree structure is delineated this concept provides more efficient and cost effective utilization of the memory as well as increased flexibility in program structure
CACM	on simulating networks of parallel processes in which simultaneous events may occur some of the problems of simulating discrete event systems particularly computer systems on a conventional digital computer are dealt with the systems are assumed to be described as a network of interconnected sequential processes briefly reviewed are the common techniques used to handle such simulations when simultaneous events do not occur can be ignored or can be handled by simple priority rules following this the problem of dealing with simultaneous events in separate processes is introduced an abstraction of this problem is developed which admits solution for a majority of commonly encountered problems the technique will either find a method of simulating the parallel events or report that none can be found in some of the latter cases it is shown to be possible to find a solution by extending the information available to the solution technique but in many cases the technique becomes computationally unfeasible when the additional information is provided
CACM	an algorithm for finding a fundamental set of cycles of a graph a fast method is presented for finding a fundamental set of cycles for an undirected finite graph a spanning tree is grown and the vertices examined in turn unexamined vertices being stored in a pushdown list to await examination one stage in the process is to take the top element v of the pushdown list and examine it i e inspect all those edges v z of the graph for which z has not yet been examined if z is already in the tree a fundamental cycle is added if not the edge v z is placed in the tree there is exactly one such stage for each of the n vertices of the graph for large n the store required in creases as n 2 and the time as n g where g depends on the type of graph involved g is bounded below by 2 and above by 3 and it is shown that both bounds are attained in terms of storage our algorithm is similar to that of gotlieb and corneil and superior to that of welch in terms of speed it is similar to that of welch and superior to that of gotlieb and corneil testsshow our algorithm to be remarkably efficient g 2 on random graphs
CACM	the damped taylors series method for minimizing a sum of squares and for solving systems of nonlinear equations algorithm 315 e4 c5
CACM	function minimization algorithm 251 e4
CACM	generation of permutations in lexicographic order algorithm 323 g6
CACM	generator of spanning trees algorithms 354 h
CACM	a base for a mobile programming system an algorithm for a macro processor which has been used as the base of an implementation by bootstrapping of processors for programming languages is described this algorithm can be easily implemented on contemporary computing machines experience with programming languages whose implementation is based on this algorithm indicates that such a language can be transferred to a new machine in less than one man week without using the old machine
CACM	compact list representation definition garbage collection and system implementation compact lists are stored sequentially in memory rather than chained with pointers since this is not always convenient the swym system permits a list to be chained compact or any combination of the two a description is given of that list representation and the operators implemented most are similar to those of lisp 1 5 the system garbage collector attempts to make all lists compact it relocates and rearranges all of list storage using temporary storage this unique list compacting garbage collection algorithm is presented in detail several classes of the macros used to implement the system are described finally consideration is given to those design factors essential to the success of a plex processing system implementation
CACM	on multiprogramming machine coding and computer organization the author feels that the interrupt feature which is available in most modern computers is a potent source of programming pitfalls and errors and that it therefore may heavily contribute to the unreliability of programs making use of it a programming scheme is presented which avoids the concept of the interrupt and permits the specification of concurrent or pseudoconcurrent activities in a supposedly more perspicuous manner it is intended to serve as a basis for the construction of operating systems which are prime examples of programs with concurrent activities the scheme includes a set of basic instructions for the generation termination and synchronization of parallel processes a set of routines representing these instructions and thereby simulating a hypothetical machine organization has been implemented and test on the ibm system 360 two programs using these instructions written in pl360 are presented
CACM	a program for the syntactic analysis of english sentences a program is described which produces syntactic analyses of english sentences with respect to a transformational grammar the main features of the analyzer are that it uses only a limited dictionary of english words and that it pursues all analysis paths simultaneously while processing the sentence from left to right the form of representation used for the dictionary and the grammar is indicated and an outline account is given of the analysis procedure techniques for keeping the size of the analysis record within reasonable limits and for avoiding the need for dynamic application of certain transformational rules are described a number of examples of output produced by the program are given the output includes timing information
CACM	the teachable language comprehender a simulation program and theory of language the teachable language comprehender tlc is a program designed to be capable of being taught to comprehend english text when text which the program has not seen before is input to it it comprehends that text by correctly relating each explicit or implicit assertion of the new text to a large memory this memory is a semantic network representing factual assertions about the world the program also creates copies of the parts of its memory which have been found to relate to the new text adapting and combining these copies to represent the meaning of the new text by this means the meaning of all text the program successfully comprehends is encoded into the same format as that of the memory in this form it can be added into the memory both factual assertions for the memory and the capabilities for correctly relating text to the memorys prior content are to be taught to the program as they are needed tlc presently contains a relatively small number of examples of such assertions and capabilities but within the system notations for expressing either of these are provided thus the program now corresponds to a general process for comprehending language and it provides a methodology for adding the additional information this process requires to actually comprehend text of any particular kind the memory structure and comprehension process of tlc allow new factual assertions and capabilities for relating text to such stored assertions to generalize automatically that is once such an assertion or capability is put into the system it becomes available to help comprehend a great many other sentences in the future thus the addition of a single factual assertion or linguistic capability will often provide a large increment in tlcs effective knowledge of the world and in its overall ability to comprehend text the programs strategy is presented as a general theory of language comprehension
CACM	filon quadrature algorithm d1
CACM	an algorithm for filon quadrature an algorithm for filon quadrature is described considerable attention has been devoted to an analysis of the round off and truncation errors the algorithm includes an automatic error control feature
CACM	error bounds for periodic quintic splines explicit error bounds for periodic quintic spline interpolation are developed the first third derivative of the periodic spline is shown to be a sixth fourth order approximation at the mesh points to the first third derivative of the function being interpolated
CACM	an algol based associative language a high level programming language for large complex associative structures has been designed and implemented the underlying data structure has been implemented using a hash coding technique the discussion includes a comparison with other work and examples of applications of the language
CACM	the mad definition facility one of the first definition facilities for higher level languages is described users of the language can define new operators and or data types into the mad language so that their use appears as if they were predefined information is given on how one writes definitions as well as on much of the motivation behind the form in which definitions are written some conclusions are drawn about future definitional facilities
CACM	computing capabilities at argentine and chilean universities the author reports on a trip to universities in argentina and chile during november 1968 describing university conditions and computing activities as elsewhere these universities are experiencing student discontent with the status quo and the solutions they are attempting contrast argentina is excluding students from participating in university government chile is allowing such participation university computing service and academic activities are limited the number of computers is small and so is the capacity none larger than an ibm 360 40 with some exception computing science academic programs are rare this situation is by no means attributable to those responsible for computing developments who strive for excellence rather the system is hard to over come universities especially those with strong european traditions adapt slowly to new academic resources and disciplines superimposed are the severe technological and economic constraints of the developing nation consequently in the absence of conscious government emphasis on strengthening computing capabilities future progress may be retarded
CACM	minit algorithm for linear programming algorithm 333 h
CACM	generation of hilbert derived test matrix algorithm 274 f1
CACM	algol 60 reference language editor algorithm 268 r2
CACM	characteristic values and associated solutions of mathieus differential equation algorithm 352 s22
CACM	on the expected lengths of sequences generated in sorting by replacement selecting in the replacement selecting technique of sorting one is interested in the ratio l j of the expected length of the j th sequence generated by the technique to the number of memory cells used using complex variable theory it is shown that l j   2 and that asymptotically the average interval between sign changes of l j  2 is 2 6662
CACM	on obtaining correct input a new approach most information put into machine readable form whether from scientific or business origins is still keypunched this paper is addressed toward the difficulty of obtaining correctly keypunched and key verified data and an alternative method is suggested in which the computer itself is used to rule out the possibility of errors in input this technique is explained and illustrated by reference to a working program which involves essentially two phases in the first phase errors are detected by the machine and subsequently in the second phase they are corrected by it
CACM	block structures indirect addressing and garbage collection programming languages have included explicit or implicit block structures to provide a naming convenience for the programmer however when indirect addressing is used as in snobol naming constraints may be introduced two modifications to snobol are described resulting in two desirable consequences 1 naming constraints disappear even when there is indirect addressing within function definitions and 2 there is a significant saving in the number of calls to the garbage collector because some garbage is collected at little expense each time a function returns to its calling program these modifications have been implemented as an extension to a snobol dialect
CACM	some techniques for using pseudorandom numbers in computer simulation an algorithm is described by which uniform pseudorandom integers may be used to construct binary numbers in which the probability that each bit in the word is a 1 bit and can assume any desired parameter value techniques for making use of such numbers in simulation programming are described
CACM	automatic contour map some methods for contour mapping by means of a digital plotter are discussed and a new method is presented that is simple enough to be implemented by programs with a rather small number of instructions about 120 fortran iv instructions are required comparisons with some methods proposed by other authors are also performed a fortran iv program implementing the proposed method is available at the istituto di elettrotecnica ed elettronica politencnico di milano
CACM	chebyshev interpolation and quadrature formulas of very high degree errata
CACM	accelerating lp algorithms it is shown how a novel method for computing related inner products can accelerate the pricing phase of lp algorithms other lp applications are indicated
CACM	generating pseudorandom numbers on a twos complement machine such as the ibm 360 the familiar multiplicative congruential generator is examined in the context of the type of twos complement arithmetic used in the ibm 360 series different sequences of residues are considered and relationships established among them it is shown that a sequence of positive and negative residues may be produced more simply and economically than with the conventional approach and yet have twice the period of the latter without loss of desirable statistical properties another easily generated sequence involving absolute values is also shown to have twice the period but with less attractive statistical properties the statistical properties of these sequences are given and related to previously established criteria
CACM	polynomial and spline approximation by quadratic programming the problem of approximation to a given function or of fitting a given set of data where the approximating function is required to have certain of its derivations of specified sign over the whole range of approximation is studied two approaches are presented in each of which quadratic programming is used to provide both the constraints on the derivatives and the selection of the function which yields the best fit the first is a modified bernstein polynomial scheme and the second is a spline fit
CACM	generation of test matrices having certain sign patterns and prescribed positive spectra a class of orthogonal transformations is presented whose members transform a given positive diagonal matrix into a matrix having one of four special sign patterns
CACM	prevention of system deadlocks a well known problem in the design of operating systems is the selection of a resource allocation policy that will prevent deadlock deadlock is the situation in which resources have been allocated to various tasks in such a way that none of the tasks can continue the various published solutions have been somewhat restrictive either they do not handle the problem in sufficient generality or they suggest policies which will on occasion refuse a request which could have been safely granted algorithms are presented which examine a request in the light of the current allocation of resources and determine whether or not the granting of the request will introduce the possibility of a deadlock proofs given in the appendixes show that the conditions imposed by the algorithms are both necessary and sufficient to prevent deadlock the algorithms have been successfully used in the the system
CACM	recovery of reentrant list structures in slip one consequence of the reference count based space recovery system employed by slip is that reentrant list structures are not recovered even when explicitly erased lisp like garbage collection schemes are free of this impediment they however depend on being able to find and mark nodes that are reachable from program variables by tracing all descendants from program variables may then be identified and collected the list creating function list of slip may be amended to mark those lists for which the programmer wishes to assume responsibility given this modification a lisp like garbage collector that recovers abandoned reentrant list structures may then be appended to the slip system
CACM	a note on storage fragmentation and program segmentation the main purpose of this paper is the presentation of some of the results of a series of simulation experiments investigating the phenomenon of storage fragmentation two different types of storage fragmentation are distinguished 1 external fragmentation namely the loss in storage utilization caused by the inability to make use of all available storage after it has been fragmented into a large number of separate blocks and 2 internal fragmentation the loss of utilization caused by rounding up a request for storage rather than allocating only the exact number of words required the most striking result is the apparently general rule that rounding up requests for storage to reduce the number of different sizes of blocks coexisting in storage causes more loss of storage by increased internal fragmentation than is saved by decreased external fragmentation described also are a method of segment allocation and an accompanying technique for segment addressing which take advantage of the above result evidence is presented of possible advantages of the method over conventional paging techniques
CACM	chebyshev solution to an overdetermined linear system algorithm 328 f4
CACM	transpose vector stored array algorithm 302 k2
CACM	determination of the square root of a positive definite matrix algorithm 298 f1
CACM	modified romberg quadrature algorithm d1
CACM	an anomaly in space time characteristics of certain programs running in a paging machine the running time of programs in a paging machine generally increases as the store in which programs are constrained to run decreases experiments however have revealed cases in which the reverse is true a decrease in the size of the store is accompanied by a decrease in running time an informal discussion of the anomalous behavior is given and for the case of the fifo replacement algorithm a formal treatment is presented
CACM	a computer system for transformational grammar a comprehensive system for transformational grammar has been designed and implemented on the ibm 360 67 computer the system deals with the transformational model of syntax along the lines of chomskys aspects of the theory of syntax the major innovations include a full formal description of the syntax of a transformational grammar a directed random phrase structure generator a lexical insertion algorithm an extended definition of analysis and a simple problem oriented programming language in which the algorithm for application of transformations can be expressed in this paper we present the system as a whole first discussing the general attitudes underlying the development of the system then outlining the system and discussing its more important special features references are given to papers which consider some particular aspect of the system in detail
CACM	generation of optimal code for expressions via factorization given a set of expressions which are to be compiled methods are presented for increasing the efficiency of the object code produced by first factoring the expressions i e finding a set of subexpressions each of which occurs in two or more other expressions or subexpressions once all the factors have been ascertained a sequencing procedure is applied which orders the factors and expressions such that all information is computed in the correct sequence and factors need be retained in memory a minimal amount of time an assignment algorithm is then executed in order to minimize the total number of temporary storage cells required to hold the results of evaluating the factors in order to make these techniques computationally feasible heuristic procedures are applied and hence global optimal results are not necessarily generated the factorization algorithms are also applicable to the problem of factoring boolean switching expressions and of factoring polynomials encountered in symbol manipulating systems
CACM	a recursive relation for the determinant of a pentadiagonal matrix a recursive relation relating leading principal minors is developed for the determinant of a pentadiagonal matrix a numerical example is included to indicate its use in calculating eigenvalues
CACM	spline function methods for nonlinear boundary value problems the solution of the nonlinear differential equation y f x y y with two point boundary conditions is approximated by a quintic or cubic spline function y x the method is well suited to nonuniform mesh size and dynamic mesh size allocation for uniform mesh size h the error in the quintic spline y x is o h 4 with typical error one third that from numerovs method requiring the differential equation to be satisfied at the mesh points results in a set of difference equations which are block tridiagonal and so are easily solved by relaxation or other standard methods
CACM	introducing computing to smaller colleges and universities    a progress report by technical means that are now routine computer service for smaller colleges and universities can be provided by remote terminals of a central facility access however is not enough effective organizational and educational methodology for introducing computing at such institutions must also be developed the experience of two years with a statewide network involving 41 institutions is discussed lessons include the importance of a separate organization representing the small colleges the necessity for on campus training for the institutions the need for some special programming and documentation to support such users and the development of curriculum by evolutionary means
CACM	simulation of traffic flows in a network a computer simulation program which deals with traffic flows in the network of a large area is described each road is segmented into blocks of several ten meter lengths and is represented by a bidirectional list in computer memory the movement of cars i e the transfer of cars from one block to the next is expressed by a proper formula this formula is based on the supposition that the speed of cars in a block is determined only by the density of cars in the block and this speed versus density curve is empirically given the numerical values this simulation scheme has its excellent point in that it makes it possible to trace the dynamic behavior of traffic flows in a variety of situations some examples of which are given for an actual area of the city of kyoto japan
CACM	three dimensional computer display a stereographic display terminal has been produced using the raster display brad recently developed at brookhaven the system uses a rotating refresh memory to feed standard television monitors to produce a stereographic display the computer calculates the projected video images of an object viewed from two separate points the resulting video maps are stored on separate refresh bands of the rotating memory the two output signals are connected to separate color guns of a color television monitor thus creating a superimposed image on the screen optical separation is achieved by viewing the image through color filters the display is interactive and can be viewed by a large group of people at the same time
CACM	degree of multiprogramming in page on demand systems a simple stochastic model is described which offers a base for understanding the relationship between the number of programs permitted to share memory the degree of multiprogramming drum traffic rates and central processing unit utilization in page on demand multiprogrammed time shared computer systems the model preserves as a key feature the property of page demand statistics which implies a burst of page demands at the beginning of any job or quantum execution the model a markov chain is analyzed numerically and the results are presented graphically for a wide range of key environment descriptive parameters implications of the results to time shared system design and programming are discussed and a calculation of the optimal degree of multiprogramming for a wide range of parameters is presented graphically
CACM	roots of polynomials by a root squaring and resultant routine algorithm 340 c2
CACM	normal random deviates algorithm 334 g5
CACM	gaussian quadrature formulas algorithm 331 d1
CACM	regular coulomb wave functions algorithm 292 s22
CACM	coulomb wave functions algorithm 300 s22
CACM	regular coulomb wave functions algorithm 292 s22
CACM	simplex method procedure employing lu decomposition algorithm 350 h
CACM	clarification of fortran standards initial progress in 1966 after four years of effort fortran became the first programming language standardized in the united states since that initial achievement study and application of the standard specifications have revealed the need for maintenance of the standards as the result of work initiated in 1967 an initial set of clarifying interpretations has been prepared the nature of the maintenance corrections to the standard specifications and completed interpretations are reported
CACM	dynamic space sharing in computer systems a formalization of relationships between space shading program behavior and processor efficiency in computer systems is presented concepts of value and cost of space allocation per task are defined and then value and cost are combined to develop a single parameter termed value per unit cost the intent is to illustrate a possible analytic approach to the investigation of the problems of space sharing and to demonstrate the method on sample problems
CACM	an automatic grading scheme for simple programming exercises a discussion is given of alterations that were made to a typical university operating system to record the results of programming exercises in three different languages including assembly language in this computer controlled grading scheme provision is made for testing with programmer supplied data and for final runs with system supplied data exercises run under the scheme may be mixed with other programs and no special recognition of exercises by the operators is necessary
CACM	chebyshev interpolation and quadrature formulas of very high degree
CACM	rough and ready error estimates in gaussian integration of analytic functions
CACM	the simplex method of linear programming using lu decomposition standard computer implementations of dantzigs simplex method for linear programming are based upon forming the inverse of the basic matrix and updating the inverse after every step of the method these implementations have bad round off error properties this paper gives the theoretical background for an implementation which is based upon the lu decomposition computed with row interchanges of the basic matrix the implementation is slow but has good round off error behavior the implementation appears as cacm algorithm 350
CACM	automated printed circuit routing with a stepping aperture a computer program for routing interconnections on a two sided printed circuit board with a regular pattern of lines pins terminals and vias feed through holes is described in this program each interconnection is given a planned routing typically down from the upper pin through a via and horizontally to the lower pin from the top a virtual aperture i e a long horizontal slit is stepped down the board the planned routing is the basis for rerouting interconnections within the aperture to resolve conflicts for lines and vias below the aperture and to maximize the effective line usage if a conflict has not been resolved before the aperture arrives at the lower pin interconnections are deleted to resolve the conflict extensions of this technique to the control of crosstalk between routed interconnections and to the problem of obtaining 100 percent interconnect are also discussed
CACM	a note on reliable full duplex transmission over half duplex links a simple procedure for achieving reliable full duplex transmission over half duplex links is proposed the scheme is compared with another of the same type which has recently been described in the literature finally some comments are made on another group of related transmission procedures which have been shown to be unreliable under some circumstances
CACM	time sharing and batch processing an experimental comparison of their values in a problem   solving situation an experimental comparison of problem solving using time sharing and batch processing computer systems conducted at mit is described in this paper this study is the first known attempt to evaluate two such systems for what may well be the predominant user population within the next decade the professionals who as nonprogrammers are using the computer as an aid in decision making and problem solving rather than as a programming end in itself statistically and logically significant results indicate equal cost for usage of the two computer systems however a much higher level of performance is attained by time sharing users there are indications that significantly lower costs would have resulted if the time sharing users had stopped work when they reached a performance level equal to that of the batch users the users speed of problem solving and their attitudes made time sharing the more favorable system
CACM	computation of jn x by numerical integration it is shown to be practical to compute jn x by numerical integration of its integral representation using the trapezoidal rule the error in this approximation was studied empirically
CACM	an algorithm for solving a special class of tridiagonal systems of linear equations an algorithm is presented for solving a system of linear equation bu k where b is tridiagonal and of a special form it is shown that this algorithm is almost twice as fast as the gaussian elimination method usually suggested for solving such systems in addition explicit formulas for the inverse and determinant of the matrix b are given
CACM	on coordination reduction and sentence analysis a class of coordination phenomena in natural languages is considered within the frame work of transformational theory to account for these phenomena it is proposed that certain machinery be added to the syntactic component of a transformational grammar this machinery includes certain rule schemata the conditions under which they are to be applied and conditions determining the sequence of subtrees on which they are to be performed a solution to the syntactic analysis problem for this class of grammars is outlined precise specification of both the generative procedure of this paper and its inverse is given in the form of lisp function definitions
CACM	simulation of outpatient appointment systems an experimental computer program is described which simulates appointment systems employed by outpatient departments of hospitals both major kinds of appointment systems individual and block can be simulated the purpose of the simulator is to enable the user to evaluate the effectiveness of alternative appointment systems in a given clinical environment
CACM	polygamma functions with arbitrary precision algorithm 349 s14
CACM	matrix scaling by integer programming algorithm 348 f1
CACM	an algorithm for hidden line elimination the algorithm presented causes the elimination of hidden lines in the representation of a perspective view of concave and convex plane faced objects on the picture plane all the edges of the objects are considered sequentially and all planes which hide every point of an edge are found the computing time increases roughly as the square of the number of edges the algorithm takes advantage of a reduced number of concave points and automatically recognizes if only one object with no concave points is considered in this last case the result is obtained in a much simpler way
CACM	analysis of boolean program models for time shared paged environments directed graphs or their associated matrices are frequently used to represent the logical structure of sequences of computer instructions such techniques are used and in addition data references are represented in a nondirected model the complete structural specification of a program is represented by a combined model a transformation of the combined model yields a new model in which additional timing information is also contained analysis of these models prior to execution yields information valuable in determining segmentation of instructions and data for a time shared environment as well as for initial page loading during execution the analysis may be used for look ahead control of page turning
CACM	an algol procedure for the fast fourier transform with arbitrary factors algorithm 339 c6
CACM	distribution of indistinguishable objects into distinguishable slots algorithm 329 g6
CACM	an efficient algorithm for sorting with minimal storage algorithm 347 m1
CACM	f test probabilities algorithm 346 s14
CACM	an algol convolution procedure based on the fast fourier transform algorithm 345 c6
CACM	proposed usa standard data communication control procedures for the usa standarad code for information interchange
CACM	pseudofiles an approach to system interfaces for high level languages using basic input output support facilities is described it is shown that this technique can provide potentially inexpensive methods for programs to communicate with deeply embedded facilities such as command language processors
CACM	organizing matrices and matrix operations for paged memory systems matrix representations and operations are examined for the purpose of minimizing the page faulting occurring in a paged memory system it is shown that carefully designed matrix algorithms can lead to enormous savings in the number of page faults occurring when only a small part of the total matrix can be in main memory at one time examination of addition multiplication and inversion algorithms shows that a partitioned matrix representation i e one submatrix or partition per page in most cases induced fewer page faults than a row by row representation the number of page pulls required by these matrix manipulation algorithms is also studied as a function of the number of pages of main memory available to the algorithm
CACM	concepts of use in contour map processing generalized techniques whose use can simplify the solution of problems relating to contour maps one of these techniques makes use of the topological properties of contour maps the topology is represented by a graphical structure in which adjacent contour lines appear as connected nodes another generalized technique consists of utilizing geometrical properties to determine the characteristics of straight lines drawn on the contour map both of these techniques have been applied to the problem of locating the ground track of an aircraft from elevation readings obtained during a flight
CACM	description of format a text processing program format is a production program which facilitates the editing and printing of finished documents directly on the printer of a relatively small 64k computer system it features good performance totally free form input very flexible formatting capabilities including up to eight columns per page automatic capitalization aids for index construction and a minimum of nontext items it is written entirely in fortran iv
CACM	information science in a ph d computer science program this report contains recommendations on a sample course curriculum in the general area of information organization and information system design in a ph d computer science program the subject area is first briefly described followed by a listing of some desirable graduate level courses suitable bibliographies are appended
CACM	exclusive simulation of activity in digital networks a technique for simulating the detailed logic networks of large and active digital systems is described essential objectives sought are improved ease and economy in model generation economy in execution time and space and a facility for handling simultaneous activities the main results obtained are a clear and useful separation of structural and behavioral model description a reduction of manual tasks in converting boolean logic into a structural model the elimination of manual processes in achieving exclusive simulation of activity an event scheduling technique which does not deteriorate in economy as the event queue grows in length and a simulation procedure which deals effectively with any mixture of serial and simultaneous activities the passage of time is simulated in a precise quantitative fashion and systems to be simulated may be combinations of synchronous and asynchronous logic certain aspects of the techniques described may be used for the simulation of network structures other than digital networks
CACM	images from computers and microfilm plotters digital computers are widely used for the processing of information and data of all kinds including the pictorial information contained in photographs and other graphical representations efficient conversion facilities for putting graphical information into the computer and retrieving it in graphical form are therefore much needed one of the most commonly employed devices for obtaining permanent graphical output from digital computers is the microfilm plotter regrettably present models have no provision for producing images with a continuous gray scale or half tones in this note several programming techniques are described for obtaining half tone pictures from a microfilm plotter under the control of a digital computer illustrative examples of several methods are given
CACM	extremely portable random number generator extremely portable subroutines are sometimes needed for which moderate quality and efficiency suffice typically this occurs for library functions like random number generation and in core sorting which are not entirely universal or are not used in a standardized way the literature on random number generators does not seem to contain an algorithm that meets requirements of this sort an extremely portable 8 line fortran program is provided which based on an important paper by coveyou and macpherson 1967 using their methods fourier analysis is applied to the probability function for the consecutive n tuples provided by our generator with n less than or equal to 4 while the small modulus which must be used to maintain portability prevents the quality of the generator from being high the generator compares well with the bounds established in the above mentioned paper
CACM	interval arithmetic determinant evaluation and its use in testing for a chebyshev system two recent papers one by hansen and one by hansen and r r smith have shown how interval arithmetic i a can be used effectively to bound errors in matrix computations in the present paper a method proposed by hasen and r r smith is compared with straightforward use of i a in determinant evaluation computational results show the accuracy and running times that can be expected when using i a for determinant evaluation an application using i a determinants in a program to test a set of functions to see if they form a chebyshev system is then presented
CACM	the logarithmic error and newtons method for the square root the problem of obtaining optimal starting values for the calculation of the square root using newtons method is considered it has been pointed out elsewhere that if relative error is used as the measure of goodness of fit optimal results are not obtained when the initial approximation is a best fit it is shown here that if instead the so called logarithmic error is used then a best initial fit is optimal for both types of error moreover use of the logarithmic error appears to simplify the problem of determining the optimal initial approximation
CACM	coding the lehmer pseudo random number generator an algorithm and coding technique is presented for quick evaluation of the lehmer pseudo random number generator modulo 2 31   1 a prime mersenne number with produces 2 31   2 numbers on a p bit greater than 31 computer the computation method is extendible to limited problems in modular arithmetic prime factorization for 2 61   2 and a primitive root for 2 61   1 the next largest prime mersenne number are given for possible construction of a pseudo random number generator of increased cycle length
CACM	on arithmetic expressions and trees a description is given of how a tree representing the evaluation of an arithmetic expression can be drawn in such a way that the number of accumulators needed for the computation can be represented in a straightforward manner this representation reduces the choice of the best order of computation to a specific problem under the theory of graphs an algorithm to solve this problem is presented
CACM	randomized binary search technique a mathematical model is developed for the mean and variance of the number of trials to recover a given document in a randomly received list of files the search method described is binary in nature and offers new potential for information retrieval systems
CACM	variable length tree structures having minimum average search time sussenguth suggests in a paper 1963 that a file should be organized as a doubly chained tree structure if it is necessary both to search and to update frequently such a structure provides a compromise between the fast search slow update characteristics of binary searching and the slow search fast update characteristics of serial searching his method however contains the limiting restriction that all terminal nodes lie on the same level of the tree this paper considers the effect of relaxing this restriction first trees which have the property that a priori the filial set of each node is well defined are studied it is proved that coding the nodes within each filial set with respect to the number of terminal nodes reachable from each is necessary and sufficient to guarantee minimum average search time then the more general case that is where the entire structure of the tree is changeable is treated a procedure is developed for constructing a tree with a minimum average search time a simple closed expression for this minimum average search time is obtained as a function of the number of terminal nodes the storage capacity required to implement the doubly chained tree structure on a digital computer is also determined finally the total cost of the structure using sussenguths cost criterion is computed it is shown that significant improvements in both the average search time and the total cost can be obtained by relaxing sussenguths restriction that all terminal nodes lie on the same level of the tree
CACM	codas a data display system codas a customer oriented data system is a user oriented data retrieval and display system the command language of the system provides the user with an easy means for specifying data retrieval and display requests data is displayed as tables and graphs produced in a format ready for publication in this paper the statements of the request language and the general system design are described
CACM	some criteria for time sharing system performance time sharing systems as defined in this article are those multiaccess systems which permit a terminal user to utilize essentially the full resources of the system while sharing its time with other terminal users it is each terminal users ability to utilize the full resources of the system that makes quantitative evaluation of time sharing systems particularly difficult six criteria are described which have been successfully used to perform first level quantitative time sharing system performance evaluation
CACM	directed random generation of sentences the problem of producing sentences of a transformational grammar by using a random generator to create phrase structure trees for input to the lexical insertion and transformational phases is discussed a purely random generator will produce base trees which will be blocked by the transformations and which are frequently too long to be of practical interest a solution is offered in the form of a computer program which allows the user to constrain and direct the generation by the simple but powerful device of restricted subtrees the program is a directed random generator which accepts as input a subtree with restrictions and produces around it a tree which satisfies the restrictions and is ready for the next phase of the grammar the underlying linguistic model is that at noam chomsky as presented in aspects of the theory of syntax the program is written in fortran iv for the ibm 360 67 and is part of a unified computer system for transformational grammar it is currently being used with several partial grammars of english
CACM	calculation of a polynomial and its derivative values by horner scheme algorithm 337 c1
CACM	f distribution algorithm 322 s14
CACM	finding a solution of n functional equations in n unknowns algorithm 314 c5
CACM	complete elliptic integrals algorithm 165 s21
CACM	students t distribution algorithm 344 s14
CACM	the role of programming in a ph d computer science program in this general paper the role of programming in advanced graduate training is discussed subject matter related to programming as well as programming per se is considered the importance and application of formalism are considered and also the need for good empirical experimentation a brief outline for a sequence of courses is included and subject headings that have been obtained from an extensive bibliography are given a bibliography of programming references is included
CACM	computing polynomial resultants bezouts determinant vs collins reduced p r s algorithm algorithms for computing the resultant of two polynomials in several variables a key repetitive step of computation in solving systems of polynomial equations by elimination are studied determining the best algorithm for computer implementation depends upon the extent to which extraneous factors are introduced the extent of propagation of errors caused by truncation of real coefficients memory requirements and computing speed preliminary considerations narrow the choice of the best algorithm to bezouts determinant and collins reduced polynomial remainder sequence p r s algorithm detailed tests performed on sample problems conclusively show that bezouts determinant is superior in all respects except for univariate polynomials in which case collins reduced p r s algorithm is somewhat faster in particular bezouts determinant proves to be strikingly superior in numerical accuracy displaying excellent stability with regard to round off errors results of tests are reported in detail
CACM	object code optimization methods of analyzing the control flow and data flow of programs during compilation are applied to transforming the program to improve object time efficiency dominance relationships indicating which statements are necessarily executed before others are used to do global common expression elimination and loop identification implementation of these and other optimizations in os 360 fortran h are described
CACM	computers in group theory a survey computers are being applied to an increasingly diverse range of problems in group theory the most important areas of application at present are coset enumeration subgroup lattices automorphism groups of finite groups character tables and commutator calculus group theory programs range from simple combinatorial or numerical programs to large symbol manipulation systems in this survey the more important algorithms in use are described and contrasted and results which have been obtained using existing programs are indicated an extensive bibliography is included
CACM	finiteness assumptions and intellectual isolation of computer scientists
CACM	efficient handling of binary data
CACM	estimates of distributions of random variables for certain computer communications traffic models a study of multiaccess computer communications has characterized the distributions underlying an elementary model of the user computer interactive process the model used is elementary in the sense that many of the random variables that generally are of interest in computer communications studies can be decomposed into the elements of this model data were examined from four operational multiaccess systems and the model is shown to be robust that is each of the variables of the model has the same distribution independent of which of the four systems is being examined it is shown that the gamma distribution can be used to describe the discrete variables approximations to the gamma distribution by the exponential distribution are discussed for the systems studied
CACM	index by subject to algorithms 1970
CACM	exponential integral ei x algorithms 385 s13
CACM	eigenvalues and eigenvectors of a real symmetric matrix algorithm 384 f2
CACM	characteristic values and associated solutions of mathieus differential equation algorithm 352 s22
CACM	optimum merging from mass storage an algorithm is displayed which yields the merge orders such that the total read time defined to be the sum of seek time plus data transfer time is minimized for a sort using mass storage the analysis is parameterized in terms of the ratio of seek time to the time it takes to fill available core with records and the file size in units of core lengths and thus it can be applied to any conventional cpu mass storage combination an explicit formula for total read time is derived in terms of the parameters which correlates very well with the total read time calculated using the optimum merge orders yielded by the algorithm the formula involves the roots of a simple transcendental equation a short table of these roots is included numerical results are graphically displayed for a wide range of the parameters it is found that the normalized read time for optimum merging on a given hardware configuration is proportional to the file length times the logarithm of the file length
CACM	the list set generator a construct for evaluating set expressions the list set generator is defined and algorithms for its use are given the list set generator is a construct which may be added to a list processing system or any system that handles sets it efficiently generates the set which results from any expression involving sets and set operators the efficiency derives from evaluating the expression as a whole and in parallel rather than evaluating subexpressions and then using those sets to arrive at the final result
CACM	improving round off in runge kutta computations with gills method a runge kutta gill scheme in common use is based on an incomplete adaptation for floating point operations of gills method an improved version reduces round off error significantly in this note the heart of the scheme is presented in fortran language it is then shown how an improved version of the method can be obtained with the addition of two fortran statements the two version is a significant improvement a numerical example comparing the two is included
CACM	an interrupt based organization for management information systems a programming structure language constructs and a supervisory system organization are proposed for the design and coding of large shared data base systems the bases for this organization are a generalized interrupt structure and the newly introduced concept of file tagging which is the process of associating program structures and interrupt generating conditions with items in the data base an algorithm for resolving conflicts which arise in scheduling the interrupt processing routines is presented dpl a programming language and supervisory system in which these concepts are implemented is used to illustrated the new organization which is proposed for management information systems
CACM	process management and resource sharing in the multiaccess system esope the main design principles of the multiaccess system esope are described emphasis is placed on basic ideas underlying the design rather than on implementation details the main features of the system include the ability given to any user to schedule his own parallel processes using system primitive operations the file memory relationship and the allocation scheduling policy which dynamically takes into account recent information about user behavior
CACM	an efficient search algorithm to find the elementary circuits of a graph a theoretically most efficient search algorithm is presented which uses an exhaustive search to find all of the elementary circuits of a graph the algorithm can be easily modified to find all of the elementary circuits with a particular attribute such as length a rigorous proof of the algorithm is given as well as an example of its application empirical bounds are presented relating the speed of the algorithm to the number of vertices and the number of arcs the speed is also related to the number of circuits in the graph to give a relation between speed and complexity extensions to undirected and s graphs are discussed
CACM	groove a program to compose store and edit functions of time a program which makes possible creating storing reproducing and editing functions of time is described the functions are typical of those generated by human beings multiple functions up to 14 are produced for long periods of time up to several hours at sufficiently high sampling rates to describe fast human reactions up to 200 samples per second the functions can be used for a variety of purposes such as the control of machine tools or sound synthesizers or anything a person normally controls the program operates on a small computer ddp 224 functions are stored on a disk file functions may be created by real time human inputs to the computer which can interact with already stored functions and computed functions real time feedback from the process being controlled is an important link in the system the environment for effective man machine interaction has been carefully nurtured
CACM	condition numbers of pei matrices
CACM	comment on the working set model for program behavior
CACM	correction to logical arithmetic on computers with twos complement binary arithmetic
CACM	a generalized method for generating argument function values
CACM	an improved algorithm to produce complex primes algorithm 401 a1
CACM	eigenvalues and eigenvectors of a real general matrix algorithm 343 f1
CACM	increasing the efficiency of quicksort algorithm 402 m1
CACM	unrecorded magnetic tape for information interchange 9 track 200 and 800 cpi nrzi and 1600 cpi pe proposed american national standard
CACM	recorded magnetic tape for information interchange 1600 cpi phase encoded proposed american national standard
CACM	a nonrecursive list compacting algorithm a simple nonrecursive list structure compacting scheme or garbage collector suitable for both compact and lisp like list structures is presented the algorithm avoids the need for recursion by using the partial structure as it is built up to keep track of those lists that have been copied
CACM	the linear quotient hash code a new method of hash coding is presented and is shown to possess desirable attributes specifically the algorithm is simple efficient and exhaustive while needing little time per probe and using few probes per lookup performance data and implementation hints are also given
CACM	neater2 a pl i source statement reformatter neater2 accepts a pl i source program and operates on it to produce a reformatted version when in the logical mode neater2 indicates the logical structure of the source program in the indentation pattern of its output logic errors discovered through neater2 logical analysis are discovered much more economically than is possible through compilation and trial runs a number of options are available to give the user full control over the output format and to maximize the utility of neater2 as an aid during the early stages of development of a pl i source deck one option usage causes neater2 to insert into each logical unit of coding a statement which will case the number of times each one is executed to be recorded during execution this feature is expected to provide a major aid in optimization of pl i programs
CACM	a multiple precision division algorithm a generalized division algorithm for use with positive integral operands is presented depending upon the algebraic relationship of the first two ciphers of the divisor one or at most two adjustments to the original divisor and dividend must be performed before the division operation can be initiated the uniqueness of this method will cause each trial cipher in the quotient to be either equal to or one greater than its final replacement
CACM	multi attribute retrieval with combined indexes in this paper a file organization scheme designed to replace the use of the popular secondary index filing scheme or inverted files on secondary key fields is described through the use of redundancy and storing keys or access numbers of the records that satisfy different combinations of secondary index values in buckets it is possible to retrieve all keys satisfying any input query derived from a subset of fields by a single access to an index file although each bucket may be used for many combinations of values and a combination of buckets may be required for a given query the method which in its degenerate case becomes the conventional secondary index filing scheme works similarly but has the following advantages 1 the elimination of multiple accesses in many cases 2 the elimination of false drops 3 the elimination of computer time to perform intersection of key sets each qualified for one secondary index field only and 4 the avoidance of long strings of keys when an index field appearing in a query has very few possible values redundancy in some cases is the same as the secondary indexing method in the general case trade off between the number of accesses for query and redundancy exists
CACM	an interactive display for approximation by linear programming an interactive program with a graphical display has been developed for the approximation of data by means of a linear combination of functions including splines selected by the user the coefficients of the approximation are determined by linear programming so as to minimize the error in either the l1 or l infinity norm auxiliary conditions such as monotonicity or convexity of the approximation can also be imposed this interactive system is described and several examples of its use are given
CACM	the use of interactive graphics to solve numerical problems with the advent of on line time sharing computer systems and graphic terminals we have available a new dimension in numerical problem solving capabilities rather than simply use the new power to achieve fast turnaround we can develop interactive routines which are easy to use and also take advantage of the insight and visual capabilities of the human problem solver several on line systems for general purpose mathematical problem solving have already been implemented as well as some special purpose systems for solving problems in a particular area such as ordinary differential equations the advantage of restricting the problem area is that the interface with a user can be greatly simplified in this paper we discuss some of the advantages accrued by such systems and design considerations for interactive routines furthermore an implementation of an on line least squares data fitting program peg is presented with results obtained from empirical data in conclusion area for future work in this field are discussed
CACM	numerical inversion of laplace transforms algorithm 368 d5
CACM	an efficient algorithm for sorting with minimal storage algorithm 347 m1
CACM	normal curve integral algorithm 304 s15
CACM	modified havie integration algorithm 400 d1
CACM	spanning tree h algorithm 399
CACM	tableless date conversion z algorithm 398
CACM	an integer programming problem h algorithm 397
CACM	students t quantiles s14 algorithm 396
CACM	students t distribution s14 algorithm 395
CACM	a formalism for translator interactions a formalism is presented for describing the actions of processors for programming languages compilers interpreters assemblers and their interactions in complex systems such as compiler compilers or extendible languages the formalism here might be used to define and answer such a question as can one do bootstrapping using a meta compiler whose metaphase is interpretive in addition an algorithm is presented for deciding whether or not a given system can be produced from a given set of component processors
CACM	transition network grammars for natural language analysis the use of augmented transition network grammars for the analysis of natural language sentences is described structure building actions associated with the arcs of the grammar network allow for the reordering restructuring and copying of constituents necessary to produce deep structure representations of the type normally obtained from a transformational analysis and conditions on the arcs allow for a powerful selectivity which can rule out meaningless analyses and take advantage of semantic information to guide the parsing the advantage of this model for natural language analysis are discussed in detail and illustrated by examples an implementation of an experimental parsing system for transition network grammars is briefly described
CACM	numerical constants algorithm
CACM	on the number of automorphisms of a singly generated automaton
CACM	comment on bells quadratic quotient method for hash code searching
CACM	regular coulomb wave functions algorithm 292 s22
CACM	decision table translation h algorithm 394
CACM	special series summation with arbitrary precision c6 algorithm 393
CACM	systems of hyperbolic pde d3 algorithm 392
CACM	increasing the efficiency of quicksort a method is presented for the analysis of various generalizations of quicksort the average asymptotic number of comparisons needed is shown to be an log 2 n a formula is derived expressing a in terms of the probability distribution of the bound of a partition this formula assumes a particularly simple form for a generalization already considered by hoare namely choice of the bound as median of a random sample the main contribution of this paper is another generalization of quicksort which uses a bounding interval instead of a single element as bound this generalization turns out to be easy to implement in a computer program a numerical approximation shows that a 1 140 for this version of quicksort compared with 1 386 for the original this implies a decrease in number of comparisons of 18 percent actual tests showed about 15 percent saving in computing time
CACM	complex matrix inversion versus real a comparison of complex matrix with real matrix inversion is made it is shown that the complex inversion can be up to twice as fast as the real inversion further the rounding error bound for complex inversion is about one eighth that of real for gaussian elimination using extended inner product accumulation the bound is half of the real system
CACM	optimal starting approximations for generating square root for slow or no divide on machine with slow or no division it is preferable to use an iterative scheme for the square root different from the classical heron scheme the problem of optimal initial approximants is considered and some optimal polynomial initial approximations are tabulated
CACM	a variation of the goodman lance method for the solution of two point boundary value problems a recently published method for the interpolative solution of nonlinear equations is improved and applied to give a significant variation of the goodman lance method for the solution of two point boundary value problems the resulting method applies in particular to the numerical solution of optimal control problems in the euler lagrange formulation quantitative estimates are presented which indicate that the variation is nearly twice as fast on some problems in the latter context
CACM	integrating square roots differential equation of the y 2 f y are difficult to integrate numerically because of the singularity at points where f y vanishes a simple trick removes the singularity
CACM	amesplot a higher level data plotting software system amesplot is an extensible software system designed to make the display of data as simple painless and neat as possible the system described is hardware independent and has been implemented on a variety of installations of different manufacturers having diverse configurations the elements common to all types of data plots are outlined and the way in which these elements may be combined into a system based on simple modules is demonstrated these modules are specified independently and are independent of the axis systems or other attributes of the plot this enables plots of any complexity to be constructed by adding or replacing modules the basic syntax of amesplot is outlined and a brief description is given of its current utility software consisting of macros to produce self scaled plots formal tablets of text interspersed with subplots map coastlines and 3 d plots the system was formulate d in a way such that the user could supply the minimum of information and it should be fully integrable with users program written in most conventional higher languages the functions of positioning locating and scaling in the layout of multiple subplots of axes labels and all other elements of the plot are handled automatically by the software system unless the user specifies otherwise the structuring of plots from multiple independent self contained subplots is described transformation projection scaling rotation or shifting of entire plots or subplots by the action of one or more simple modules is possible the user may interact freely with amesplot at three levels enabling him to construct his own data markers alphabetic characters and transformations and to produce a variety of artistic and other effects
CACM	an interactive software system for computers aided design an application to circuit project the characteristics of an interactive software system intended to constitute an interface between designer and computer during various steps of the design process are presented the main emphasis is given to the description of the features of the two high level user oriented languages operating at different levels on which the interaction is based the first one is imol an interactive monitor language which is designed to perform the overall and control functions of the software system its design criteria provide the user with commands which are both simple and efficient in order to perform all the functions needed in computer aided circuit design the second one is coif a circuit oriented graphic language which is designed to describe generate and manipulate graphic problem specifications it is an extension of fortran with graphic type variables so that the designer who is familiar with fortran need not learn a new language the application to computer aided circuit design is in particular examined on the other hand the adopted design criteria provide sufficient generality to extend the use of the two languages to different computer assisted applications
CACM	a procedure for generation of three dimensional half toned computer graphics presentations a description is given of an algorithm for producing computer generated half tone presentations of three dimensional polygonal surface structures this algorithm achieves a significant increase in speed of computation over the warnock algorithm developed at the university of utah and implemented also on the coordinated science laboratory cdc 1604 computer system at the university of illinois the history leading to the algorithm development and then the algorithm itself are described results are presented and are compared with computer runs achieved by the warnock approach an extension of the procedure to variable position illumination sources is also given
CACM	proposed revision of american national standard x3 21 1967 rectangular holes in twelve row punched cards
CACM	proposed american national standard
CACM	algorithms policy revised august 1970
CACM	gaussian quadrature formulas algorithm 331 d1
CACM	simpsons rule for multiple integration algorithm 233 d1
CACM	unitary symmetric polynomials z algorithm 391
CACM	sequency ordered walsh functions s22 algorithm 390
CACM	binary ordered walsh functions s22 algorithm 389
CACM	rademacher function s22 algorithm 388
CACM	function minimization and linear search e4 algorithm 387
CACM	a technique for generating almost optimal floyd evans productions for precedence grammars a technique is developed for generating almost optimal floyd evans productions given a precedence grammar a graph formulation is used for the problem of merging productions the productions generated correspond to the minimum cost inverse arborescence of that graph the validity of the technique is demonstrated for weak precedence grammars defined here but the productions mechanically generated for any precedence grammar can often be modified in such a way that correct almost optimal parsers are obtained
CACM	the instrumentation of multics an array of measuring tools devised to aid in the implementation of a prototype computer utility is discussed these tools include special hardware clocks and data channels general purpose programmed probing and recording tools and specialized measurement facilities some particular measurements of interest in a system which combines demand paging with multiprogramming are described in detail where appropriate insight into effectiveness or lack there of of individual tools is provided
CACM	sorting in a paging environment this sorting study was part of an extensive measurement project undertaken on the m44 44x an experimental paging system which was conceived and implemented at ibm research in order to explore the virtual machine concept the study was concerned with the implementation of sorting procedures in the context of the dynamic paging environment characteristic of virtual memory machines descriptions of the experimental sort programs and analysis of the performance measurement results obtained for them are presented the insight gained from the experimental effort is used to arrive at a set of broad guidelines for writing sort programs for a paging environment
CACM	full table quadratic searching for scatter storage the quadratic residue search method for hash tables avoids much of the clustering experienced with a linear search method the simple quadratic search only accesses half the table it has been shown that when the length of the table is a prime of the form 4n 3 where n is an integer the whole table may be accessed by two quadratic searches plus a separate access for the original entry point a search method is presented which is computationally simple has all the advantages of the quadratic search and yet accesses all the table in one sweep
CACM	normalization techniques for hand printed numerals family of pattern standardization techniques based on geometrical projection is applied to a file of digitized hand printed numerals obtained from sales clerks the principle involves transforming a quadrilateral specified in terms of the convex hull of each pattern into a square the amount of overlap within each class of characters versus the amount between classes is used to evaluate the degree of normalization achieved with respect to other published methods including size and shear normalization through moments
CACM	the allocation of computer resources is pricing the answer the widespread use of complex third generation computing systems has led to a much broader concern about the means by which the resources of these systems are allocated among the user community one means that is suggested more and more frequently is a pricing procedure in this paper the manner in which one would like to allocate computing resources is considered and then the extent to which a pricing mechanism fits this mold is discussed inasmuch as pricing must serve as a rationing mechanism at times consideration is given to the means by which prices can be adjusted flexibly in order to make a dynamic allocation of resources consideration is also given to the means by which users can be insulated from the harmful effects of frequent price fluctuations although the subject of pricing has been given a lot of attention recently a number of misconceptions persist about its purpose and its operation an attempt is made to clarify some of these misunderstandings and to highlight the advantages and disadvantages and to highlight the advantages and disadvantages of pricing two illustrative pricing systems are also discussed in order to demonstrate the applicability of pricing in quite different environments
CACM	a comment on axiomatic approaches to programming
CACM	note on an anomaly in paging
CACM	a note on data base deadlocks
CACM	comments on a paper by lowe
CACM	students t distribution jacobi polynomials modified romberg quadrature factorial analysis of variance algorithms 332 344 351 359
CACM	exponential integral algorithm 385 s13
CACM	ricatti bessel functions of first and second kind algorithm 22 s17
CACM	greatest common divisor of n integers and multipliers a1 algorithm 386
CACM	exponential integral s13 algorithm 385
CACM	context sensitive parsing this paper presents a canonical form for context sensitive derivations and a parsing algorithm which finds each context sensitive analysis once and only once the amount of memory required by the algorithm is essentially no more than the required to store a single complete derivation in addition a modified version of the basic algorithm is presented which blocks infinite analyses for grammars which contain loops the algorithm is also compared with several previous parsers for context sensitive grammars and general rewriting systems and the difference between the two types of analyses is discussed the algorithm appears to be complementary to an algorithm by s kuno in several respects including the space time trade off and the degree of context dependence involved
CACM	algorithm and bound for the greatest common divisor of n integers a new version of the euclidean algorithm for finding the greatest common divisor of n integers a i and multipliers x i such that gcd x 1 a 1 x n a n is presented the number of arithmetic operations and the number of storage locations are linear in n a theorem of lame that gives a bound for the number of iterations of the euclidean algorithm for two integers is extended to the case of n integers an algorithm to construct a minimal set of multipliers is presented a fortran program for the algorithm appears as comm acm algorithm 386
CACM	file structures using hashing functions a general method of file structuring is proposed which uses a hashing function to define tree structure two types of such trees are examined and their relation to trees studied in the past is explained results for the probability distributions of path lengths are derived and illustrated
CACM	space time trade offs in hash coding with allowable errors in this paper trade offs among certain computational factors a given set of messages two new hash coding methods are examined and compared with a particular conventional hash coding method the computational factors considered are the size of the hash area space the time required to identify a message as a nonmember of the given set reject time and an allowable error frequency the new methods are intended to reduce the amount of space required to contain the hash coded information from that associated with conventional methods the reduction in space is accomplished by exploiting the possibility that a small fraction of errors of commission may be tolerable in some applications in particular applications in which a large amount of data is involved and a core resident hash area is consequently not feasible using conventional methods in such applications it is envisaged that overall performance could be improved by using a smaller core resident hash area in conjunction with the new methods and when necessary by using some secondary and perhaps time consuming test to catch the small fraction of errors associated with new methods an example is discussed which illustrates possible areas of application for the new methods analysis of the paradigm problem demonstrates that allowing a small number of test messages to be falsely identified as members of the given set will permit a much smaller hash area to be used without increasing reject time
CACM	the mobile programming system stage2 stage2 is the second level of a bootstrap sequence which is easily implemented on any computer it is a flexible provided by stage2 are summarized and the implementation techniques which have made it possible to have stage2 running on a new machine with less than one man week of effort are discussed the approach has been successful on over 15 machines of widely varying characteristics
CACM	conversational access to a 2048 word machine lap6 is an on line system running on a 2048 word linc which provides full facilities for text editing automatic filing and file maintenance and program preparation and assembly it focuses on the preparation and editing of continuously displayed 23 040 character text strings manuscripts which can be positioned anywhere by the user and edited by simply adding and deleting lines as though working directly on an elastic scroll other features are available through a uniform command set which itself can be augmented by the user the machine although small aids program design by providing display scope and premarked randomly addressable linc tapes as standard items in an environment similar to that of a sophisticated terminal the tapes are logically similar to a disk priority was given to the design of efficient tape algorithms to minimize the limitations of the small memory techniques developed for handling scroll editing filing and the layered system structure are outlined lap6 is used by about 2000 people in 11 countries its design was strongly influenced by performance criteria established in interviews held with linc users themselves during the specification period
CACM	an interactive command generating facility a facility to permit conversationally controlled tasks to be executed in a noninteractive environment is proposed a means by which programs can generate interactive time sharing commands and receive the corresponding output response is presented the commands will be invoked as if they had been typed at a console keyboard it is argued that this facility will help overcome some of the current limitations in man computer communication a set of functions to accomplish the above which could be embedded into any string processing language is suggested and necessary information pertinent to implementation of the facility on existing time sharing systems is given
CACM	permutations of a set with repetitions algorithm 383 g6
CACM	combinations of m out of n objects algorithm 382 g6
CACM	permanent function of a square matrix i and ii algorithm 361 g6
CACM	modified romberg quadrature algorithm 351 d1
CACM	shellsort algorithm 201 m1
CACM	treesort 3 algorithm 245 m1 the certification of an algorithm can take the form of a proof that the algorithm is correct as an illustrative but practical example algorithm 245 treesort 3 for sorting an array is proved correct
CACM	eigenvalues and eigenvectors of a real symmetric matrix f2 algorithm 384
CACM	permutations of a set with repetitions algorithm 383 g6
CACM	combinations of m out of n objects algorithm 382 g6
CACM	a relational model of data for large shared data banks future users of large data banks must be protected from having to know how the data is organized in the machine the internal representation a prompting service which supplies such information is not a satisfactory solution activities of users at terminals and most application programs should remain unaffected when the internal representation of data is changed and even when some aspects of the external representation are changed change in data representation will often be needed as a result of changes in query update and report traffic and natural growth in the types of stored information existing noninferential formatted data systems provide users with tree structured files or slightly more general network models of the data in section 1 inadequacies of these models are discussed a model based on n ary relations a normal form for data base relations and the concept of a universal form for data base relations and the concept of a universal data sublanguage are introduced in section 2 certain operations on relations other than logical inference are discussed and applied to the problems of redundancy and consistency in the users model
CACM	incorporating origin shifts into the qr algorithm for symmetric tridiagonal matrices the qr iteration for the eigenvalues of a symmetric tridiagonal matrix can be accelerated by incorporating a sequence of origin shifts the origin shift may be either subtracted directly from the diagonal elements of the matrix or incorporated by means of an implicit algorithm both methods have drawbacks the direct method can unnecessarily degrade small eigenvalues while the implicit method can effectively loose the shift and thereby retard the convergence this paper presents a new method which has neither drawback
CACM	comparison of several adaptive newton cotes quadrature routines in evaluating definite integrals with peaked integrands this report compares the performance of five different adaptive quadrature schemes based on newton cotes 2n 1 point rules n 1 2 3 4 5 in approximating the set of definite integrals integral 1 x 2 p 2 dx with relative accuracy e
CACM	accurate floating point summation this paper describes an alternate method for summing a set of floating point numbers comparison of the error bound for this method with that of the standard summation method shows that it is considerably less sensitive to propagation of round off error
CACM	automatic parsing for content analysis although automatic syntactic and semantic analysis is not yet possible for all of an unrestricted natural language text some applications of which content analysis is one do not have such a stringent coverage requirement preliminary studies show that the harvard syntactic analyzer can produce correct and unambiguous identification of the subject and object of certain verbs for approximately half of the relevant occurrences this provides a degree of coverage for content analysis variables which compares favorably to manual methods in variables which compares favorably to manual methods in which only a sample of the total available text is normally processed
CACM	a pl i program to assist the comparative linguist a practical pl i program is described which can assist comparative linguists to determine the regular sound correspondences between genetically related languages the investigator must arrange data for input by aligning pairs of suspected cognates the program tabulates the correspondences and uses list processing techniques to sort and count them each pair of words is then assigned a relative value that is a function of the total frequency in the data of each correspondence found in that pair of words the output is a list of all correspondence types with their frequency of occurrence in the data and a separate listing of each correspondence with all word pairs showing that correspondence unless their relative value is below an arbitrarily chosen cutoff point the article explains the usefulness as well as the limitations of the programs and illustrates its use with a small portion of hypothetical data
CACM	scheduling to reduce conflict in meetings conflicts in scheduling can be treated as defining an undirected linear graph independently of the relation of the activities in conflict to additional constraints of time and space each connected component of such a graph which can be found by an algorithm described by gotlieb and corneil corresponds to a set of events that must be scheduled at different times
CACM	on the conversion of decision tables to computer programs the use of execution time diagnostics in pinpointing ambiguities in decision tables is discussed it is pointed out that any attempt at resolving ambiguities at compile time will in general be impossible it is shown that as a consequence tree methods of converting decision tables to programs are inadequate in regard to ambiguity detection two algorithms for programming decision tables whose merits are simplicity of implementation and detection of ambiguities at execution time are presented the first algorithm is for limited entry decision tables and clarifies the importance of proper coding of the information in the decision table the second algorithm programs a mixed entry decision table directly without going through the intermediate step of conversion to a limited entry form thereby resulting in storage economy a comparison of the algorithms and others proposed in the literature is made some features of a decision table to fortran iv translator for the ibm 7044 developed by the authors are given
CACM	on the feasibility of voice input to an on line computer processing system an on line digital computer processing system is considered in which an ordinary telephone is the complete terminal device input to the computer being provided as a sequence of spoken words and output to the user being audio responses from the machine the feasibility of implementing such a system with a fortran like algebraic compiler as the object processor is considered details of a specific word recognition program are given this technique depends on three simplifying restrictions namely a small vocabulary set known speakers and a moment of silence between each input word experimental results are presented giving error rates for different experimental conditions as well as the machine resources required to accommodate several users at a time the results show that at this time it is both economically and logically feasible to handle at least 40 users at a time with an ibm 360 65 computer
CACM	subroutine to perform in situ transposition of a rectangular matrix algorithm 380
CACM	gomory algorithm 263a h
CACM	random vectors uniform in solid angle algorithm 381 g5
CACM	in situ transposition of a rectangular matrix algorithm 380 f1
CACM	a language for treating graphs a language for the representation of graph is described and the formulation of graph operations such as node and or link deletion or insertion union intersection comparison and traversal of graphs is given graphs are represented by linked lists the language is syntactically defined as an extension to algol 60 and it is translated into algol by means of a syntax driven compiler application areas for this language are operation research network problems control theory traffic problems etc
CACM	gedanken a simple typeless language based on the principle of completeness and the reference concept gedanken is an experimental programming language with the following characteristics 1 any value which is permitted in some context of the language is permissible in any other meaningful context in particular functions and labels are permissible results of functions and values of variables 2 assignment and indirect addressing are formalized by introducing values called reference which in turn possess other values the assignment operation always affects the relation between some reference and its value 3 all compound data structures are treated as functions 4 type declarations are not permitted the functional approach to data structures and the use of references insure that any process which accepts some data structure will accept any logically equivalent structure regardless of its internal representation more generally any data structure may be implicit i e it may be specified by giving an arbitrary algorithm for computing or accessing its components the existence of label variables permits the construction of coroutines quasi parallel processes and other unorthodox control mechanisms a variety of programming examples illustrates the generality of the language limitations and possible extensions are discussed briefly
CACM	an algorithm for the construction of bounded context parsers an algorithm is described which accepts an arbitrary context free grammar and constructs a bounded context parser for it whenever such a parser exists in the first part of the paper the definition of a context free grammar and the working of a bounded context parser are recalled the notion of reduction class for a context free grammar is then introduced and its connection with the structure of a bounded context parser is indicated next pushdown automata which generate the different reduction classes of a context free grammar are defined finally the algorithm is described it essentially carries out an exhaustive study of all possible runs of the pushdown automata generating the reduction classes in the second part the utility of the algorithm is discuss ed in the light of the experience gained from its use in compiler design the algorithm is claimed to be particularly useful in the simultaneous design of a language and a compiler for it
CACM	the application of sequential sampling to simulation an example inventory model four different sequential sampling procedures are applied to the analysis of data generated by a computer simulation experiment with a multi item inventory model for each procedure the cost of computer time required to achieve given levels of statistical precision is calculated also the cost of computer time using comparable fixed sample size methods is calculated the computer costs of fixed sample size procedures versus sequential sampling procedures are compared
CACM	translation equations errata
CACM	operations on generalized arrays with the genie compiler operations on vectors matrices and higher dimensional storage arrays are standard features of most compilers today the elements of such structures are usually restricted to be scalars for many sophisticated applications this restriction can impose cumbersome data representations an efficient system has been devised and implemented which allows the elements of multidimensional arrays to themselves be multidimensional arrays this system was developed from a storage structure in which the location length and content of each array is described by a codeword which can be interpreted by the system code words may describe arrays containing more codewords thus providing all needed descriptive information for hyperstructures of any form
CACM	a programming system for the on line analysis of biomedical images a preliminary description of the software for a computer display system is given with special emphasis on the man machine interaction this system is intended for a wide variety of biomedical applications as an example the methods are applied to the karyotyping of chromosomes the system is separated into four programming tasks picture transformations file maintenance picture structuring and display management picture structuring is considered as the vehicle for man machine communication a prototype data format for pictures called a picture form is developed structure operators are defined which manipulate picture forms to produce new pictures forms many of the ideas are taken from the symbolic mathematical laboratory at mit conceived by marvin minsky
CACM	an algol construction for procedures as parameters of procedures
CACM	comment on lawlers multilevel boolean minimization
CACM	comment on multiprogramming under a page on demand strategy
CACM	comments on a paper by wallace and mason
CACM	a formal system for information retrieval from files
CACM	filon quadrature algorithm 353 d1
CACM	modified romberg quadrature algorithm 351 d1
CACM	solution of linear programs in 0 1 variables by implicit enumeration algorithm 341 h
CACM	sqank algorithm 379 d1
CACM	discretized newton like method for solving a system of simultaneous nonlinear equations algorithm 378 c5
CACM	cubic splines on uniform meshes a very simple procedure is presented for constructing cubic splines periodic or nonperiodic on uniform meshes arcs of two cubics suffice to construct a basis of cardinal splines an algorithm is given which requires only minimal storage and computation and permits easy trade off of one against the other
CACM	the cyclical majority problem the problem of the cyclical majority is presented and some new simulated results for 3 4 5 40 issues ad 3 5 7 37 judges are reported
CACM	representations for space planning problems involving the arrangement of objects in two  or three space where the objective function primarily consists of derivatives of the distance between objects or their arrangement are called space planning problems the representational requirements for this problem area are defined and compared with current computer graphic languages four alternative data structures that allow automated space planning are described and compared
CACM	on multiprogramming machine coding and computer organization
CACM	the nucleus of a multiprogramming system this paper describes the philosophy and structure of a multiprogramming system that can be extended with a hierarchy of operating systems to suit diverse requirements of program scheduling and resource allocation the system nucleus simulates an environment in which program execution and input output are handled uniformly as parallel cooperating process es a fundamental set of primitives allows the dynamic creation and control of a hierarchy of processes as well as the communication among them
CACM	some complete calculi for matrices a matrix calculus is introduced with the intention of developing data structures suitable for a high level algorithmic language for mathematical programming the paper investigates how the special structure of matrices can be described and utilized for efficient computing by saving memory space and superfluous operations sequences of matrices and sequences of sequences of matrices are considered and matrix operators areext ended to sequence operators and cumulative operators algorithms are given which use symbol manipulation of matrix expressions so as to find the forms best suited for computation these forms are called normal forms several completeness results are obtained in the sense that for each expression an equivalent expression in normal form can be found within a specified calculus
CACM	syntax directed documentation for pl 360 the language pl 360 together with its phrase structure grammar is used as a concrete basis for illustrating an idea called syntax directed documentation this idea is 1 to use the phrase structure of a program to define the structure of a formal documentation for that program 2 to use the syntactic types and identifiers in the resulting structure to trigger the automatic formation of questions to the programmer whose answers will become part of that documentation and 3 to provide automatic storage and retrieval facilities so that other programmers who want to understand or modify the program can access the resulting documentation which is cross indexed in various ways by syntactic types and objects a small pl 360 program already found in the literature is worked out as an example
CACM	creation and control of internal data bases under a fortran programming environment a method is described for the definition of a users common structure and the automatic generation of the necessary common dimension equivalence and type declarations for each of the users routines the definition for the common is contained in an easy to modify form thus allowing the control of general communications of data between routines the described system has been implemented on the ibm 7094 cdc 6000 series and the ibm 360 the method has proved to be invaluable for the definition and control of common in many large scale programs
CACM	a note on the complement of inherently ambiguous context free languages
CACM	comment on a paging anomaly
CACM	another method of converting from hexadecimal to decimal
CACM	a number system for the permutations
CACM	netflow algorithm 336 h
CACM	prime number algorithm 310 a1
CACM	symbolic expansion of algebraic expressions algorithm 377 r2
CACM	pdel a language for partial differential equations conventional computer methods available to solve continuous system problems characterized by partial differential equations are very time consuming and cumbersome a convenient easy to learn and to use high level problem oriented language to solve and study partial differential equation problems has been designed a practical translator for the language has also been designed and a working version of it has been constructed for a significant portion of the language this partial differential equation language pdel is outlined and the highlights of the translator are briefly summarized
CACM	a deductive question answer for natural language inference the question answering aspects of the protosynthex iii pro totype language processing system are described and exemplified in detail the system is written in lisp 1 5 and operates on the q 32 time sharing system the systems data structures and their semantic organization the deductive question answering formalism of relational properties and complex relation forming operators and the question answering procedures which employ these features in their operation are all described and illustrated examples of the systems performance and of the limitations of its question answering capability are presented and discussed it is shown that the use of semantic information in deductive question answering greatly facilitates the process and that a top down procedure which works from question to answer enables effective use to be made of this information it is concluded that the development of protosynthex iii into a practically useful system to work with large data bases is possible but will require changes in both the data structures and the algorithms used for question answering
CACM	a comparison of error improvement estimates for adaptive trapezoid integration various simple choices of error improvement estimates for the trapezoid rule are studied to demonstrate a comparison procedure which is relatively independent of the profusion of adaptive search and stopping strategies comparisons are based on x r the inclusion of the noninteger powers makes this more realistic than the usual polynomial based comparison behavior near the singularity was found to be the dominant factor and a new estimate based on a constant curvature assumption and parametric differences was considered slightly better than the other choices considered
CACM	on an algorithm for nonlinear minimax approximation certain nonlinear minimax approximation problems are characterize d by properties which permit the application of special algorithms mainly based on the exchange algorithms of remes 1934 1935 for their solution in this paper the application to problems of this type of a general nonlinear algorithm due to osborne and watson 1969 is considered examples are given to illustrate that this algorithm can give satisfactory results and in particular can successfully solve problems which lead to difficulties with the more conventional specialist method
CACM	measurements of segment size distributions of segment sizes measured under routine operating con ditions on a computer system which utilizes variable sized segments the burroughs b5500 are discussed the most striking feature of the measurements is the large number of small segments about 60 percent of the segments in use contain less than 40 words although the results are certainly not installation independent and although they are particularly influenced by features of the b5500 algol system they should be relevant to the design of new computer systems especially with respect to the organization of paging schemes
CACM	experiments with the m n tree searching program the m n procedure is an improvement to the mini max backing up procedure widely used in computer program for game playing and other purposes it is based on the principle that it is desirable to have many options when making decisions in the face of uncertainty the mini max procedure assigns to a max min node the value of the highest lowest valued successor to that node the m n procedure assigns to a max min node some function of the m n highest lowest valued successors an m n procedure was written in lisp to play the game of kalah and it was demonstrated that the m n procedure is significantly superior to the mini max procedure the statistical significance of important conclusions is given since information on statistical significance has often been lacking in papers on computer experiments in the artificial intelligence field these experiments can perhaps serve as a model for future work
CACM	a program to teach programming the teach system was developed at mit to ease the cost and improve the results of elementary instruction in programming to the student teach offers loosely guided experience with a conversational language which was designed with teaching in mind faculty involvement is minimal a term of experience with teach is discussed pedagogically the system appears to be successful straightforward reimplementation will make it economically successful as well similar programs of profound tutorial skill will appear only as the results of extended research the outlines of his research are beginning to become clear
CACM	t test probabilities algorithm 321 students t distribution algorithm 344
CACM	eigenvalues and eigen vectors of a real general matrix algorithm 343 f
CACM	ortho algorithm 127 f5
CACM	least squares fit by f x acos bx c algorithm 376 e2
CACM	fitting data to one exponential algorithm 375 e2
CACM	restricted partition generator algorithm 374 a1
CACM	number of doubly restricted partitions algorithm 373 a1
CACM	an interactive computer system using graphical flowchart input an interactive computer system operational on a graphical computer terminal is described this system was designed to demonstrate a method of programming by computer interpretation of a flowchart the user draws a description of a sampled data system and specifies description is transmitted to a large scale computer the design is simulated and a graphic representation of the processed signal is returned to the scope a successful design may require numerous modifications of the original design a graphical interactive system provides an environment to perform this iterative process efficiently and effectively
CACM	computer education in a graduate school of management several years of experience have led to the belief that the creative design and evaluation of management information systems requires a thorough understanding of the related computer technology concepts such as paging and priority interrupt systems can best be explained at the machine language level any machine used for exposition should fulfill several criteria it should 1 raise as few spurious issues as possible 2 allow without undue effort the solution of interesting problems 3 be capable of exposing all outstanding issues of significance capable of exposing all outstanding issues of significance within the chosen machine 4 be seful for pursuing issues in great depth when appropriate 5 not be committed to the equipment provided by any manufacturer 6 be able to provide the student with diagnostic aids to a great depth 7 allow the student ready access to the machine 8 be capable of extension to expose new issues as they come along we have constructed a simulated machine and its associated software which meets these criteria this system called the prism system is documented by a primer and a reference manual
CACM	the quadratic quotient method a hash code eliminating secondary clustering secondary clustering as a cause of hash code inefficiency is discussed and a new hashing method based on its elimination is presented comparisons with previous methods are made both analytically and empirically
CACM	a variation on sorting by address calculation the principles of address calculation and merging are combined to yield an efficient sorting technique detailed flowcharts of the most important program steps are included the characteristics of the proposed sort are discussed
CACM	the use of quadratic residue research a quadratic residue search method has previously been suggested to avoid the clustering usually encountered when hash address collisions occur and linear search methods are used the search size because of the property of quadratic residues is limited to one half of the storage table it is shown that for some classes of prime numbers the complement of the set of quadratic residues can easily be determined and hence the entire table of size p where p is that prime number can be searched
CACM	an efficient context free parsing algorithm a parsing algorithm which seems to be the most efficient general context free algorithm known is described it is similar to both knuths lr k algorithm and the familiar top down algorithm it has a time bound proportional to n 3 where n is the length of the string being parsed in general it has a n 2 bound for unambiguous grammars and it runs in linear time on a large class of grammars which seems to include most practical context free programming language grammars in an empirical comparison it appears to be superior to the top down and bottom up algorithms studied by griffiths and petrick
CACM	spelling correction in systems programs several specialized techniques are shown for efficiently incorporating spelling correction algorithms in to compilers and operating systems these include the use of syntax and semantics information the organization of restricted keyword and symbol tables and the consideration of a limited class of spelling errors sample 360 coding for performing spelling correction is presented by using systems which perform spelling correction the number of debugging runs per program has been decreased saving both programmer and machine time
CACM	translation equations input limited transduction expressions or translation equations are used to describe the syntax and left context sensitive semantics for context free languages a formal procedure is given for deriving from a set of translation equations the specifications for a pushdown translator the translator consists of mealy form finite state automata interacting by means of a pushdown stack within the framework described string recognition and parsing may be treated as special cases of the translation problem
CACM	the multistore parser for hierarchical syntactic structures a syntactic parser is described for hierarchical concatenation patterns that are presented to the analyzer in the form of linear strings particular emphasis is given to the system of significant addresses by means of which processing times for large scale matching procedures can be substantially reduced the description makes frequent use of examples taken from the fully operational implementation of the parser in an experimental english sentence analyzer by structuring an area of the computers central core storage in such a way that the individual locations of bytes and bits come to represent the data involved in the matching procedure the shifting of information is reduced to a minimum and the searching of lists is eliminated altogether the matches are traced by means of binary masks and the state of single bits determines the operational flow of the procedure the method could be implemented with any interpretive grammar provided it can be expressed by the functional classification of the items composing the input hierarchical structures
CACM	a formal system for information retrieval from files a generalized file structure is provided by which the concepts of keyword index record file directory file structure directory decoding and record retrieval are defined and from which some of the frequently used file structures such as inverted files index sequential files and multilist files are derived two algorithms which retrieve records from the generalized file structure are presented
CACM	fortran tausworthe pseudorandom number generator
CACM	interchange rolls of perforated tape for information interchange proposed american national standard
CACM	representation for calen dar date for machine to machine data interchange proposed american national standard
CACM	an efficient algorithm for sorting with minimal storage algorithm 347 m1
CACM	derivatives algorithm 282 s22
CACM	an algorithm to produce complex primes csieve algorithm 372 a1
CACM	partitions in natural order algorithm 371 a1
CACM	general random number generator algorithm 370 g5
CACM	generator of random numbers satisfying the poisson distribution algorithm 369 g5
CACM	numerical inversion of laplace transforms algorithm 368 d5
CACM	a note on minimal length polygonal approximation to a digitized contour a method for extracting a smooth polygonal contour from a digitized image is illustrated the ordered sequence of contour points and the connection graph of the image are first obtained by a modified ledley algorithm in one image scan a minimal perimeter polygon subjected to specified constraints is then chosen as the approximating contour the determination of the minimal polygon can be reduced to a nonlinear programming problem solved by an algorithm which takes into account the weak bonds between variables some examples are presented and the corresponding computing times are listed
CACM	experience with an extensible language an operational extensible language system is described the system and its base language are appraised with respect to efficiency flexibility and utility for different categories of users
CACM	natural language question answering systems 1969 recent experiments in programming natural language question answering systems are reviewed to summarize the methods that have been developed for syntactic semantic and logical analysis of english strings it is concluded that at least minimally effective techniques have been devised for answering questions from natural language subsets in small scale experimental systems and that a useful paradigm has evolved to guide research efforts in the field current approaches to semantic analysis and logical inference are seen to be effective beginnings but of questionable generality with respect either to subtle aspects of meaning or to applications over large subsets of english generalizing from current small scale experiments to language processing systems based on dictionaries with thousands of entries with correspondingly large grammars and semantic systems may entail a new order of complexity and require the invention and development of entirely different approaches to semantic analysis and questions answering
CACM	a processor allocation method for time sharing a scheduling algorithm is proposed which is intended to minimize changes of tasks on processors and thereby reduce over head the algorithm also has application to more general resource allocation problems it is implemented by means of a method for efficiently handling dynamically changing segmented lists
CACM	recursive computation of certain derivatives a study of error propagation a brief study is made of the propagation of errors in linear first order difference equations the recursive computation of successive derivatives of e x x and cos x x is considered as an illustration
CACM	automatic segmentation of cyclic program structures based on connectivity and processor timing time shared multiprogrammed and overlayed batch systems frequently require segmentation of computer programs into discrete portions these program portions are transferred between executable and peripheral storage whenever necessary segmentation of program s in a manner that reduces the frequency of such transfers is the subject of this paper segmentation techniques proposed by c v ramamoorthy are subject to limitations that arise when the preferred segment size is not compatible with the physical restrictions imposed by the available computing equipment a generalization of ramamoorthys suggestions is made in order to allow their application when circumstances are other than ideal
CACM	rapid computation of weights of interpolatory quadrature rules d1 algorithm 417
CACM	rapid computation of coefficients of interpolation formulas e1 algorithm 416
CACM	algorithm for the assignment problem rectangular matrices h algorithm 415
CACM	an extension of the munkres algorithm for the assignment problem to rectangular matrices the assignment problem together with munkres proposed algorithm for its solution in square matrices is presented first then the authors develop an extension of this algorithm which permits a solution for rectangular matrices timing results obtained by using an adapted version of silvers algol procedure are discussed and a relation between solution time and problem size is given
CACM	rapid computation of general interpolation formulas and mechanical quadrature rules let f have n continuous on a closed interval a b and let l be a linear functional the attempt is made to approximate l f with l q where q is a polynomial approximating f algorithms are developed for rapid computation of l q for a wide class of selections of q which includes the lagrangian and hermitian rules as special cases
CACM	a note on a modification of nordsiecks method using an off step point
CACM	new lisp techniques for a paging environment the system described herein employs the block concept and that of global and local variables in addition to the methods applied in most lisp systems also a new means of list representation is used local sequential for lists created during compilation and block level sequential for those created dynamically a new garbage collection algorithm has been introduced to make lists as compact as possible partial garbage collection is performed after each block exit instead of total garbage collection when storage is exhausted the algorithm does not use the customary flagging procedure this combination of features has eliminated the need for a free list and effectively minimizes the number of pages used at any moment
CACM	bliss a language for systems programming a language bliss is described this language is designed so as to be especially suitable for use in writing production software systems for a specific machine the pdp 10 compilers operating systems etc prime design goals of the design are the ability to produce highly efficient object code to allow access to all relevant hardware features of the host machine and to provide a rational means by which to cope with the evolutionary nature of systems programs a major feature which contributes to the realization of these goals is a mechanism permitting the definition of the representation of all data structures in terms of the access algorithm for elements of the structure
CACM	implementation of the substring test by hashing a technique is described for implementing the test which determines if one string is a substring of another when there is low probability that the test will be satisfied it is shown how the operation can be speeded up considerably if it is preceded by a test on appropriately chosen hash codes of the strings
CACM	retrieval update speed tradeoffs using combined indices in a paper in the november 1970 communications of the acm v y lum introduced a technique of file indexing named combined indices this technique permitted decreased retrieval time at the cost of increased storage space this paper examines combined indices under conditions of file usage with different fractions of retrieval and update tradeoff curves are developed to show minimal cost of file usage by grouping various partially combined indices
CACM	algorithmic selection of the best method for compressing map data strings the best of a dozen different methods for compressing map data is illustrated the choices are generated by encoding data strings sequence of like codes by three methods and in four directions relationships are developed between compression alternatives to avoid comparing all of them the technique has been used to compress data from forest resource maps but is widely applicable to map and photographic data reduction
CACM	reconstruction of pictures from their projections there are situations in the natural sciences and medicine e g in electron microscopy and x ray photography in which it is desirable to estimate the gray levels of a digital picture at the individual points from the sums of the gray levels along straight lines projections at a few angles usually in such situations the picture is far from determined and the problem is to find the most representative picture three algorithms are described all using monte carlo methods which were designed to solve this problem the algorithms are applicable in a large and varied number of fields the most important uses may be the reconstruction of possibly asymmetric particles from electron micrographs and three dimensional x ray analysis
CACM	chebyshev approximation of continuous functions by a chebyshev system of functions e2 algorithm 414
CACM	on accurate floating point summation the accumulation of floating point sums is considered on a computer which performs t digit base b floating point addition with exponents in the range  m to m an algorithm is given for accurately summing n t digit floating point numbers each of these n numbers is split into q parts forming qn t digit floating point numbers each of these is then added to the appropriate one of n auxiliary t digit accumulators finally the accumulators are added together to yield the computed sum in all qn n 1 t digit floating point additions are performed under usual conditions the relative error in the computed sum is at most t 1 v b 1 t for some v further with an additional q n 1 t digit additions the computed sum can be corrected to full t digit accuracy for example for the ibm 360 b 16 t 14 m 63 m 64 typical values for q and n are q 2 and n 32 in this case becomes n 32 768 and we have t 1 v b 1 t 4x16  13
CACM	automation of etching pattern layout help heuristic etching pattern layout program is an application program developed to computerize the tedious and error prone although vitally important wiring design of printed circuit boards help helps automate a design stage one step closer to production than logical design it can be used to design wiring patterns of two layer circuit boards on which ics in dual in line packages as well as discrete components such as transistors and resistors have been placed help employs two methods of wiring one is the heuristic method which simulates human approaches to wiring design and the other is the theoretically interesting but time consuming method of maze running based on the lees algorithm help performs more than 90 percent of required wiring by the heuristic path with respect to a performance function for each point to point and point to line connection it can bring the number of successful wiring connections very close to 100 percent
CACM	optimizing the polyphase sort various dispersion algorithms for the polyphase sorting procedure are examined the optimum algorithm based on minimizing the total number of unit strings read is displayed the logic of this algorithm is rather complicated hence several other new dispersion algorithms with more straightforward logic are presented of the simple dispersion algorithms discussed the horizontal is best it does approximately one fourth to one and one half percent less reading and writing than most algorithms in use today an additional two and one fourth to three percent improvement can be achieved by utilizing the modified optimum algorithm this algorithm is relatively straightforward but it requires a fairly close estimate of the total number of unit strings before the dispersion begins
CACM	using computers in higher education past recommendations status and needs data from a survey conducted with national science foundation support which was published in december 1970 is reviewed and it is pointed out that with regard to computers in higher education national goals stated in the rosser and pierce reports have not been attained quality was lacking in hardware or courses in nearly half of the associate and bachelors degree programs in data processing computer science etc offered in 1966 67 a plea is made for continuing studies on status and goals for computing in higher education improvement of degree programs and a national testing laboratory for educational technology
CACM	the composition of semantics in algol 68 the main features of algol 68 are explained from a semantic point of view it is shown how the language permits the composition of values and actions i e ultimately programs from a minimum set of primitives with a few fundamental recursive rules of composition the associated syntax is briefly reviewed an attempt has been made to obtain a structured and simple introduction to both algol 68 and its orthogonal design
CACM	entcaf and entcre evaluation of normalized taylor coefficients of an analytic function c5 algorithm 413
CACM	concurrent control with readers and writers the problem of the mutual exclusion of several independent processes from simultaneous access to a critical section is discussed for the case where there are two distinct classes of processes known as readers and writers the readers may share the section with each other but the writers must have exclusive access two solutions are presented one of the case where we wish minimum delay for the readers the other for the case where we wish writing to take place as early as possible
CACM	user program measurement in a time shared environment a general discussion of the measurement of software systems is followed by a description of a hardware and software scheme for measuring user programs in a time shared environment the tx 2 computer at mit lincoln laboratory was used for the implementation of such a system and the characteristics of this implementation are reported a scenario showing the system in use is presented finally it is shown how other time sharing systems may provide similar measuring facilities
CACM	display procedures although the use of structured display files is widespread in interactive computer graphics these structures present a number of problems which tend to restrict their generality and usefulness this paper discusses some of these problems and suggests an alternative approach to display system design which avoids the use of structured display files this technique employs display procedures to generate information for display by including transformations within calls to these procedures it is possible both to simplify the specification of pictures and to speed up their generation display procedures permit picture elements to be defined conditionally and also facilitate the processing of inputs from pointing devices the paper is illustrated by examples from aversion of the euler language in which display procedures were implemented
CACM	experiments with an automated instructional system for numerical methods a computer system was developed at purdue university to teach portions of an undergraduate course in numerical methods each instructional unit or lesson is divided into three modes of instruction which allow the student to press from a computer controlled presentation to a student controlled investigation the system is designed as a classroom independent course of study and has been used for two semesters by students in lieu of conventional classroom instruction initial measures of effectiveness student acceptance and operational cost are the result of testing the system independent of instructor intervention the system is operational on a cdc 6500 with teletype terminals
CACM	clarification of fortran standards second report in 1966 after four years of effort fortran became the first programming language standardized in the united states since that initial achievement study and application of the standard specifications have revealed the need for maintenance of the standards as the result of work initiated in 1967 an initial set of clarifying interpretations was prepared and this clarification was published in communications of the acm in may 1969 that work has continued and has resulted in the preparation of this second set of clarifying interpretations the nature of the maintenance and the new set of corrections to and interpretations of the standard specifications are reported
CACM	toward an understanding of data structures this paper presents a notation and formalism for describing the semantics of data structures this is based on directed graphs with named edges and transformations on these graphs in addition an implementation facility is described which could be part of a programming language which allows a programmer who has expressed the semantics of an algorithm in terms of the graphs to then specify the implementation of some of his data structures in order to gain efficiency
CACM	comment on cheneys list compaction algorithm
CACM	average binary search length for dense ordered lists
CACM	a stopping criterion for the newton raphson method in implicit multistep integration algorithms for nonlinear systems of ordinary differential equations
CACM	a note on best one sided approximations
CACM	canonical structure in attribute based file organization a new file structure for attribute based retrieval is proposed in this paper it allows queries involving arbitrary boolean functions of the attribute value pairs to be processed without taking intersections of lists the structure is highly dependent on the way in which the file is to be used and is uniquely determined by the specification of the allowed queries thus for example the structure for retrieval on the basis of ranges of values of a given attribute would be very different from one where only retrieval on the basis of a single value is permitted the file organization being proposed is based on the atoms of a boolean algebra generated by the queries the desirable properties claimed for this structure are proved and file maintenance questions are discussed
CACM	an algorithm for the blocks and cutnodes of a graph corrigendum
CACM	an efficient bit table technique for dynamic storage allocation of 2 n word blocks an efficient bit table technique for dynamic storage allocation of 2 n word blocks which requires a minimized amount of memory for bookkeeping purposes is described the technique has been tested in an implementation of the list processing language l 6 a number of ideas incorporated in the processor are also described
CACM	education related to the use of computers in organizations the acm curriculum committee on computer education for management has been carrying out a study on curriculum development in management information systems education in colleges and universities under a grant from the national science foundation this position paper provides a framework for the study preliminary conclusions are presented on the need for education in administrative information systems and appropriate college curricula and courses are suggested also the role of professional societies and organizations using computers is discussed and the plans of the committee are outlined the initial approach of the committee has been to describe the education necessary for the effective use of computers in organizations to classify the positions for which education is required and to survey educational programs now available
CACM	symbolic integration the stormy decade three approaches to symbolic integration in the 1960s are described the first from artificial intelligence led to slagles saint and to a large degree to moses sin the second from algebraic manipulation led to manoves implementation and to horowitz and tobeys reexamination of the hermite algorithm for integrating rational functions the third from mathematics led to richardsons proof of the unsolvability of the problem for a class of functions and for rischs decision procedure for the elementary functions generalizations of rischs algorithm to a class of special functions and programs for solving differential equations and for finding the definite integral are also described
CACM	general relativity and the application of algebraic manipulative systems the paper describes some applications of symbolic algebra systems to problems of general relativity including the derivation of the field equations the petrov classification of a metric and the solution of the field equations in the presence of matter in a simple case attention is drawn to the strictly algebraic difficulties encountered in this work
CACM	automated algebraic manipulation in celestial mechanics in this paper we consider some of the applications of automated algebraic manipulation which have been made in celestial mechanics particular attention is paid to the use of poisson series and a typical problem in perturbation theory is described the requirements of processors for use in celestial mechanics are considered and compared with those for general manipulation packages some future directions for research using these systems are briefly outlined to illustrate the relative simplicity of the algorithm required in celestial mechanics a typical integration problem is considered in an appendix
CACM	algebraic simplification a guide for the perplexed algebraic simplification is examined first from the point of view of a user who needs to comprehend a large expression and second from the point of view of a designer who wants to construct a useful and efficient system first we describe various techniques akin to substitution these techniques can be used to decrease thesize of an expression and make it more intelligible to a user then we delineate the spectrum of approaches to the design of automatic simplification capabilities in an algebraic manipulation system systems are divided into five types each type provides different facilities for the manipulation and simplification of expressions finally we discuss some of the theoretical results related to algebraic simplification we describe several positive results about the existence of powerful simplification algorithms and the number theoretic conjectures on which they rely results about the nonexistence of algorithms for certain classes of expressions are included
CACM	list tracing in systems allowing multiple cell types list processing systems have each allowed the use of only a single size and configuration of list cell in this paper a system is described which allows the use of arbitrarily many different sizes and configurations of list cells possibly not specified until run time
CACM	the altran system for rational function manipulation a survey altran is a complete system for symbolic computation with rational functions in several variables with integer coefficients it has been designed and implemented to handle large problems with ease and efficiency considerable effort has been spent to ensure a minimum amount of machine dependence in the implementation thus permitting the system to be installed quickly and easily on a variety of computing machines in this paper a brief description of the language run time data structures and implementation is given
CACM	applications of symbol manipulation in theoretical physics this paper surveys the applications of symbolic computation techniques to problems in theoretical physics particular emphasis is placed on applications in quantum electrodynamics where the most activity has occurred
CACM	solution of simultaneous nonlinear equations
CACM	graph plotter j6 algorithm 412
CACM	three procedures for the stable marriage problem h algorithm 411
CACM	the stable marriage problem the original work of gale and shapley on an assignment method using the stable marriage criterion has been extended to find all the stable marriage assignments the algorithm derived for finding all the stable marriage assignments is proved to satisfy all the conditions of the problem algorithm 411 applies to this paper
CACM	subexpression ordering in the execution of arithmetic expressions an arithmetic expression can often be broken down into its component subexpressions depending on the hardware environment in which the expression is to be executed these subexpressions can be evaluated in serials in parallel or in a combination of these modes this paper shows that expression execution time can be minimized only if consideration is given to the ordering of the subexpressions in particular subexpressions should be executed in order of decreasing memory and processor time requirements this observation is valid for configurations ranging from a uniprocessor with an unbuffered main memory to multiprocessor with a cache buffer memory if the number of subexpressions which can be executed in parallel exceeds the number of available processors then execution of some of these subexpressions must be postponed a procedure is given which combines this requirement with the earlier ordering considerations to provide an optimal execution sequence
CACM	buffer allocation in merge sorting a fixed buffer allocation for merge sorting is presented here which minimizes the number of input output operations for a given order of merge when sorting on movable arm disks the number of seeks is equal to the number of input output operations and the seek time usually controls the sort time first some standard terminology is introduced then the input buffer allocation method is described followed by an analysis of the improvement to be expected over more conventional allocation this analysis makes use of a particular distribution function an analysis of a completely different distribution is given which yields similar results this suggests that the results do not depend on a particular distribution function an optimum output buffer size is also determined it is concluded that this buffering allocation can significantly reduce the time of merge sorting on movable arm disks when the input data are not random and that this output buffer allocation should be used whether the data is random or not
CACM	an algorithm for the blocks and cutnodes of a graph an efficient method is presented for finding blocks and cutnodes of an arbitrary undirected graph the graph may be represented either i as an ordered list of edges or ii as a packed adjacency matrix if w denotes the word length of the machine employed the storage in machine words required for a graph with n nodes and m edges increases essentially as 2 m n in case i or n 2 win case ii a spanning tree with labeled edges is grown two edges finally bearing different labels if and only if they belong to different blocks for both representations the time required to analyze a graph on n nodes increases as n g where g depends on the type of graph 1 g 2 and both bounds are attained values of g are derived for each of several suitable families of test graphs generated by an extension of the web grammar approach the algorithm is compared in detail with that proposed by read for which 1 g 3
CACM	a language extension for graph processing and its formal semantics a simple programming language extension graspe for processing directed graphs is defined graspe consists of a type of directed graph data structure and a set of primitive operations for manipulating these structures graspe may be most easily implemented by embedding it in a host language emphasis is placed both on graspe itself and on its method of definition commonly the definition of a language involves definition of the syntactic elements and explanation of the meaning to be assigned them the semantics the definition of graspe here is solely in terms of its semantics that is the data structures and operations are defined precisely but without assignment of a particular syntactic representation only when the language is implemented is assignment of an explicit syntax necessary an example of an implementation of graspe embedded in lisp is given as an illustration the advantages and disadvantages of the definition of a language in terms of its semantics are discussed
CACM	simple lr k grammars a class of context free grammars called the simple lr k or slr k grammars is defined this class has been shown to include weak precedence and simple precedence grammars as proper subsets how to construct parsers for the slr k grammars is also shown these parser construction techniques are extendible to cover all of the lr k grammars of knuth they have been implemented and by direct comparison proved to be superior to precedence techniques not only in the range of grammars covered but also in the speed of parser construction and in the size and speed of the resulting parsers
CACM	a programmer training project a project is described whose purpose is to train selected black residents of the albany schenectady area in computer programming and arrange for jobs for them in the computer field both the organization and curriculum of the course are discussed
CACM	the state of computer oriented curricula in business schools 1970 the acm committee on computer education for management supported by a national science foundation grant is established to appraise the state of the art and to develop a series of recommendations for improving computer education for management to provide the committee with material for its study of curricular needs five regional meetings in the united states were held in 1970 at each of which a broad cross section of invited academicians and practitioners considered the state of curricula in business schools three topics were covered curricula for the general manager computer related material in required and functional courses and curricula for students concentrating on computer based information systems an analysis of the minutes of the meetings revealed a common set of experiences which raised similar pedagogic and economic issues this presentation gives a summary of the discussions a condensation of the pedagogic and substantive concerns raised and consideration of the resource allocation issues involved preliminary to the committees recommendations for improving computer education for management this report has been prepared to provide the participants and the administrators of their institutions with background information for the ongoing task of course development chairman of the ten man committee is daniel teichroew the university of michigan
CACM	interrupt driven programming
CACM	binary summation
CACM	on the meaning of names in programming systems it is assumed that there is a similarity of function between the data names of a programming language and the file names of an operating system the two functions are discussed in terms of the same basic concepts in order to identify the extent to which they overlap it is suggested that there is some similarity between the idea of a file directory and a storable object of type context manipulations with contexts are then discussed at length it is noted that there is a simple extension of churchs lambda notation that deals nicely with these ideas of context manipulation whereas a function can be regarded as the abstraction based upon the first two terms of the expression lambda name list expression value list it is found that a context can be viewed as an abstraction based upon the first two terms in the equivalent expression mu name list value list expression
CACM	a note on compiling fixed point binary multiplications an algorithm is developed for compiling as a sequence of shifts additions and subtractions many fixed point binary multiplications involving a constant the most significant characteristics of the algorithm are the simplicity of the test which determines if the algorithm should be applied and the degree to which it suggests efficient object code
CACM	numerical properties of the ritz trefftz algorithm for optimal control in this paper the ritz trefftz algorithm is applied to the computer solution of the state regulator problem the algorithm represents a modification of the ritz direct method and is designed to improve the speed of solution and the storage requirements to the point where real time implementation becomes feasible the modification is shown to be more stable computationally than the traditional ritz approach the first concern of the paper is to describe the algorithm and establish its properties as a valid and useful numerical technique in particular such useful properties as definiteness and reasonableness of condition are established for the method the second part of the paper is devoted to a comparison of the new techniques with the standard procedure of numerically integrating a matrix riccati equation to determine a feedback matrix the new technique is shown to be significantly faster for comparable accuracy
CACM	computer science a conceptual framework for curriculum planning two views of computer science are considered a global view which attempts to capture broad characteristics of the field and its relationships to other fields and a local view which focuses on the inner structure of the field this structure is presented in terms of the kinds of knowledge problems and activities that exist within the discipline as well as the relations between them an approach to curriculum planning in computer science is presented which is guided by the structure of the field by the fact that change is an important feature of the situation and by the expectation that computer science will continue to increase its working contacts with other disciplines
CACM	an approach to the optimum design of computer graphics systems display system designers are faced with the difficult task of selecting major subsystems in an intelligent way each subsystem is chosen from large numbers of alternatives the selection is based on considerations such as system response time system cost and the distribution of data storage and processing between the graphics processor and its supporting data processing system the work reported here develops an objective quantitative design procedure and helps give a better understanding of now to configure display systems this is accomplished by means of a mathematical model of a computer driven graphics system the parameters of the model are functions of the capabilities of the graphics hardware and of the computational requirements of the graphics application the model can be analyzed using numerical queueing analysis or simulation to obtain an average response time prediction by combining the model with an optimization the best graphics system configuration subject to a cost constraint is found for several applications the optimum configurations are in turn used to find general display system design guidelines
CACM	generation of rosary permutations expressed in hamiltonian circuits systematic generation of a specific class of permutations fundamental to scheduling problems is described in a nonoriented complete graph with n vertices hamitonian circuits equivalent to 5 n   1 specific permutations of n elements termed rosary permutations can be defined each of them corresponds to two circular permutations which mirror image each other and is generated successively by a number system covering 3 4 n 1 sets of edges every set of edges e k 1 e k k 3 k n 1 is determined recursively by constructing a hamiltonian circuit with k vertices from a hamiltonian circuit with k 1 vertices starting with the hamiltonian circuit of 3 vertices the basic operation consists of transposition of a pair of adjacent vertices where the position of the pair in the permutation is determined by e k two algorithms treating the same example for five vertices are presented it is very easy to derive all possible n permutations from the 5 n   1 rosary permutations be cycling the permutations and by taking them in the reverse order procedures which can be performed fairly efficiently by computer
CACM	function minimization
CACM	algorithm 410 partial sorting m1
CACM	another recursion induction principle an inductive method for proving things about recursively defined functions is described it is shown to be useful for proving partial functions equivalent and thus applicable in proofs about interpreters for programming languages
CACM	on implementation of label variables variables of label mode are conventionally implemented with a technique which fails to trap certain programming errors fine grained calendar clocks have recently become available these allow implementation of label variables via a new technique which traps all programming errors of this variety
CACM	how to keep the addresses short an algorithm is presented for minimizing the sum of the lengths of the blocks of coding produced by an assembler or compiler when 1 the length of each computer instruction is assumed to be either long or short long if the memory location addressed is more than a predetermined distance from the current location short otherwise and 2 there are blocks of instructions whose beginnings origins are separated by prespecified amounts for example some computers permit either 8 bit addressing interpreted relative to the location counter or full 16 bit addressing of all of memory when assembling or compiling two or more blocks of instructions which have many mutual references in such a computer there is no simple iterative procedure for keeping as many of the addresses short as possible this paper demonstrates that a wide class of problems of this type can be formulated as covering problems solvable by means of elementary arithmetic operations on the column vectors of a ternary matrix
CACM	on the optimal detection of curves in noisy pictures a technique for recognizing systems of lines is presented in this technique the heuristic of the problem is not embedded in the recognition algorithm but is expressed in a figure of merit a multistage decision process is then able to recognize in the input picture the optimal system of lines according to the given figure of merit due to the global approach greater flexibility and adequacy in the particular problem is achieved the relation between the structure of the figure of merit and the complexity of the optimization process is then discussed the method described is suitable for parallel processing because the operations relative to each state can be computed in parallel and the number of stages is equal to the length n of the curves or to log2 n if the approximate method is used
CACM	a man machine approach toward solving the traveling salesman problem the traveling salesman problem belongs to an important class of scheduling and routing problems it is also a subproblem in solving others such as the warehouse distribution problem it has been attacked by many mathematical methods with but meager success only for special forms of the problem or for problems with a moderate number of points can it be solved exactly even if very large amounts of computer time are used heuristic procedures have been proposed and tested with only slightly better results this paper describes a computer aided heuristic technique which uses only a modest amount of computer time in real time to solve large 100 200 point problems this technique takes advantage of both the computers and the humans problem solving abilities the computer is not asked to solve the problem in a brute force way as in many of todays heuristics but it is asked to organize the data for the human so that the human can solve the problem easily the technique used in this paper seems to point to new directions in the field of man machine interaction and in the field of artificial intelligence
CACM	the merit of regional computing networks one of the suggested means for stimulating the spread of computing capabilities in institutions of higher learning is through the construction of regional computing networks one such network has been constructed in the san francisco bay area by stanford university this paper reports upon the lessons learned from the operation of the network over the past two years a major impact of the network was not so much the computer power delivered to the schools as the awakening of computing awareness and the fostering of capability development at these schools the expertise and assistance from the central facility as well as the sharing of ideas among the participants were other important benefits both the quality and variety of services provided by the central facility were found to play a key role in the effectiveness of the network a regional network brings many benefits and should not be judged as a purveyor of raw computer power alone
CACM	introduction to feature analysis of generalized data base management systems this paper is a separately published introduction to a main report which analyzes the features of generalized data base management systems this introduction gives a review of the current state of the art in these systems and discusses the differences and similarities between capabilities found in host language systems and those found in self contained systems after some discussion of the problems of data independence and binding the four user levels are identified and described technical problems facing future designers are described the first of these is that of handling existing stored data and the next is that of providing more complex data structures than those already available in conventional programming languages the problem of high level interrogation and update functions acting on network structures is mentioned followed by a discussion of the problem of catering to a high volume of transactions initiated from terminals by parametric users the lowest level of user the use of cobol as a basis for further development work is considered at some length with respect to data structures host language capabilities and self contained capabilities this section also assesses the effect of the data base task group proposals the final section outlines the ten major topics in the main body of the full report
CACM	a sparse matrix package part i f4 algorithm 408
CACM	on complement division the division algorithm theorem is expressed in a form that permits it to serve as the basis for devising division operations that produce both quotient and remainder in complement form algorithms for division yielding complement results are derived for numbers represented in any base greater than one both radix and radix less one complementation schemes are considered the binary form of the algorithms thus includes both twos and ones complement implementation the problem of quotient overflow for complement results is dealt with as is that of selecting an appropriate form of the remainder condition for complement division
CACM	animator an on line two dimensional film animation system animator is a computer animation system which was designed to overcome some of the inherent disadvantages associated with conventional computer animation techniques the dec 338 serves as an input terminal for movie making allowing the trial and error design of picture sequences in a conversational mode during all stages on the system input elements light pen pushbuttons and teletype is maintained at the users request this record is sent to the ibm 360 75 where the s d 4020 instructions necessary to produce the same sequence of pictures can be generated it is anticipated that one of the primary contributions of animator will be the provision of a facility which will allow any professor to produce his own expository film strips
CACM	dynamic microprogramming processor organization and programming a dynamically microprogrammed processor is characterized by a small 4 k 64 bit word read write micro storage the access time of this storage is similar to the cycle time of the machine 50 100 nsec this microstorage is used to contain both data and subroutines the micro instructions in such a processor differ from the conventional in that they perform only purely combinatorial operations sequencing is under the control of the microinstruction the presence of the read write microstorage permits a more flexible assignment of resources than the read only storage in particular the processor developed in this paper stresses the simultaneous operation within the microinstruction of the adder shifter masker and testing facilities of the processor a microassembly language is developed and the overhead involved in subroutine linkages is analyzed the efficiency of a flexible software linkage scheme is examined as to its overhead for various subroutine characteristics finally three examples of problem oriented programming are considered and the resulting coding is compared against a system 360 assembly language version with the technology normalized
CACM	key to address transform techniques a fundamental performance study on large existing formatted files the results of a study of eight different key to address transformation methods applied to a set of existing files are presented as each method is applied to a particular file load factor and bucket size are varied over a wide range in addition appropriate variables pertinent only to a specific method take on different values the performance of each method is summarized in terms of the number of accesses required to get to a record and the number of overflow records created by a transformation peculiarities of each method are discussed practical guidelines obtained from the results are stated finally a proposal for further quantitative fundamental study is outlined
CACM	program development by stepwise refinement the creative activity of programming to be distinguished from coding is usually taught by examples serving to exhibit certain techniques it is here considered as a sequence of design decisions concerning the decomposition of tasks into subtasks and of data into data structures the process of successive refinement of specifications is illustrated by a short but nontrivial example from which a number of conclusions are drawn regarding the art and the instruction of programming
CACM	difsub for solution of ordinary differential equations d2 algorithm 407
CACM	exact solution of linear equations using residue arithmetic f4 algorithm 406
CACM	the automatic integration of ordinary differential equations an integration technique for the automatic solution of an initial value problem for a set of ordinary differential equations is described a criterion for the selection of the order of approximation is proposed the objective of the criterion is to increase the step size so as to reduce solution time an option permits the solution of stiff differential equations a program embodying the techniques discussed appears in algorithm 407
CACM	storage utilization in a memory hierarchy when storage assignment is performed by a hashing algorithm the utilization of storage is studied in a two level memory hierarchy the first storage level which is the fast store is divided into a number of storage areas when an entry is to be filed in the hierarchy a hashing algorithm will attempt to place the entry into one of these areas if this particular area is full then the entry will be placed into the slower second level store even though other areas in the first level store may have space available given the n entries have been filed in the entire hierarchy an expression is derived for the expected number of entries filed in the first level store this expression gives a measure of how effectively the first level store is being used by means of examples storage utilization is then studied as a function of the hashing algorithm the number of storage areas into which the first level store is divided and the total size of the first level store
CACM	a scheduling algorithm for a computer assisted registration system this paper presents the scheduling algorithm used in the computer assisted registration system at the university of tennessee notation is defined and the logic of the algorithm necessary to implement educational policy is described results from the first terms implementation are presented
CACM	toward automatic program synthesis an elementary outline of the theorem proving approach to automatic program synthesis is given without dwelling on technical details the method is illustrated by the automatic construction of both recursive and iterative programs operating on natural numbers lists and trees in order to construct a program satisfying certain specifications a theorem induced by those specifications is proved and the desired program is extracted from the proof the same technique is applied to transform recursively defined functions into iterative programs frequently with a major gain inefficiency it is emphasized that in order to construct a program with loops or with recursion the principle of mathematical induction must be applied the relation between the version of the induction rule used and the form of the program constructed is explored in some detail
CACM	scanned display computer graphics a television like scanned display system has been successfully implemented on a honeywell ddp 224 computer installation the scanned image is stored in the core memory of the computer and software scan conversion is used to convert the rectangular coordinates of a point to the appropriate word and bit in an output display array in core storage results thus far indicate that flicker free displays of large amounts of data are possible with reasonably fast graphical interaction a scanned image of size 240 x 254 points is displayed at a 30 frame per second rate
CACM	f distribution
CACM	roots of matrix pencils the generalized eigenvalue problem f2 algorithm 405
CACM	complex interval arithmetic complex interval arithmetic is defined using real interval arithmetic complex interval division is defined so as to assure smallest possible resulting intervals
CACM	application of game tree searching techniques to sequential pattern recognition a sequential pattern recognition spr procedure does not test all the features of a pattern at once instead it selects a feature to be tested after receiving the result of that test the procedure either classifies the unknown pattern or selects another feature to be tested etc medical diagnosis is an example of spr in this paper the authors suggest that spr be viewed as a one person game played against nature chance virtually all the powerful techniques developed for searching two person strictly competitive game trees can easily be incorporated either directly or by analogy into spr procedures in particular one can incorporate the mini average backing up procedure and the gamma procedure which are the analogues of the minimax backing up procedure and the alpha beta procedure respectively some computer simulated experiments in character recognition are presented the results indicate that the approach is promising
CACM	on the probability distribution of the values of binary trees an integral equation is derived for the generating function for binary tree values the values reflecting sorting effort the analysis does not assume uniformly distributed branching ratios and therefore is applicable to a family of sorting algorithms discussed by hoare singleton and van emden the solution to the integral equation indicates that using more advanced algorithms in the family makes only minor reductions in the expected sorting effort but substantially reduces the variance in sorting effort statistical tests of the values of several thousand trees containing up to 10 000 points have given first second and third moments of the value distribution function in satisfactory agreement with the moments computed from the generating function the empirical tests as well as the analytical results are in agreement with previously published results for the first moment in the cases of uniform and nonuniform distribution of branching ratio and for the second moment in the case of uniform distribution of branching ratio
CACM	experiments in automatic learning for a multipurpose heuristic program an automatic learning capability has been developed and implemented for use with the multiple multipurpose program that learns heuristic tree searching program which is presently being applied to resolution theorem proving in predicate calculus multiples proving program pp uses two evaluation functions to guide its search for a proof of whether or not a particular goal is achievable thirteen general features of predicate calculus clauses were created for use in the automatic learning of better evaluation functions for pp a multiple regression program was used to produce optimal coefficients for linear polynomial functions in terms of the features also automatic data handling routines were written for passing data between the learning program and the proving program and for analyzing and summarizing results data was generally collected for learning regression analysis from the experience of pp a number of experiments were performed to test the effectiveness and generality of the learning program results showed that the learning produced dramatic improvements in the solutions to problems which were in the same domain as those used for collection learning data learning was also shown to generalize successfully to domains other than those used for data collection another experiment demonstrated that the learning program could simultaneously improve performance on problems in a specific domain and on problems in a variety of domains some variations of the learning program were also tested
CACM	an analysis of some time sharing techniques the effectiveness of certain time sharing techniques such as program relocation disk rotational delay minimization and swap volume minimization is investigated summary data is presented and the findings are discussed the vehicle for this investigation was a simula based simulation model reflecting an early framework for a planned burroughs b6500 time sharing system inasmuch as the b6500 system is based upon the use of variable sized segments and a dynamic overlay procedure data is also presented which provides some indication of the effectiveness of this type of organization in a time sharing environment the design characteristics and operational capabilities of the simulation model are also described
CACM	a policy driven scheduler for a time sharing system the service received by a process from a time sharing operating system can be characterized by a resource count sum w i r ij where r ij is the number of units of service received by process i from resource i and w i is the cost per unit of the service each class of users can be characterized by a policy function which specifies the amount of service a user who belongs to this class should receive as a function of time priority changes dynamically as a function of the difference between the service promised to the user by the policy function and the service he actually receives a scheduling and swapping algorithm which keeps the resource count of each process above its policy function will provide the specified level of service overhead can be reduced by avoiding swaps of process which have received at least his level of service the algorithm has been implemented in a general purpose operating system and it has provided significantly better service to interactive and to batch jobs than the previous scheduler
CACM	conversion of limited entry decision tables to computer programs a proposed modification to pollacks algorithm pollack has proposed an algorithm for converting decision tables into flowcharts which minimize subsequent execution time when compiled into a computer program two modifications of this algorithm are proposed the first relies on shannons noiseless coding theorem and the communications concept of entropy but does not completely test the else rule the second modification completely tests the else rule but results in more executions than the first modification both modifications result in modification guarantees a globally optimal solution
CACM	comment on the conversion of decision tables to computer programs
CACM	comment on londons certification of algorithm 245
CACM	minit algorithm for linear programming algorithm 222 h
CACM	complex gamma function s14 algorithm 404
CACM	circular integer partitioning a1 algorithm 403
CACM	further evidence for the analysis of algorithms for the zero one programming problem the purpose of this note is to report computational experience additional to that recently summarized by gue et al with two algorithms for the zero one linear programming problem an error in gues paper is corrected the utility of one of the algorithms as a suboptimizer is indicated
CACM	proof of a program find a proof is given of the correctness of the algorithm find first a informal description is given of the purpose of the program and the method used a systematic technique is described for constructing the program proof during the process of coding it in such a way as to prevent the intrusion of logical errors the proof of termination is treated as a separate exercise finally some conclusions relating to general programming methodology are drawn
CACM	comments on prevention of system deadlocks habermanns method of deadlock prevention is discussed where deadlock is defined as a system state from which resource allocations to certain processes are not possible it is shown that the scheduler may introduce artificial deadlocks which habermanns method does not prevent permanent blocking is the situation where certain processes never receive their resource requests it is shown that deadlock prevention does not necessarily eliminate permanent blocking a method of preventing permanent blocking is given
CACM	construction of rational and negative powers of a formal series some methods are described for the generation of fractional and negative powers of any formal series such as poisson series or chebyshev series it is shown that with the use of the three elementary operations of addition subtraction and multiplication all rational positive and negative powers of a series can be constructed there are basically two approaches the binomial theorem and the iteration methods both methods are described here and the relationship between them is pointed out some well known classical formulas are obtained as particular cases and it is shown how the convergence properties of these formulas can be improved with very little additional computations finally at the end of the article some numerical experiments are described with chebyshev series and with fourier series
CACM	a language for treating geometric patterns in a two dimensional space in this paper cadep a problem oriented language for positioning geometric patterns in a two dimensional space is presented although the language has been specifically designed for the automatic generation of integrated circuit masks it turns out to be well suited also for such other placement problems as architecture design urban planning logical and block diagram representation the design criteria the structure and the specific features of cadep are illustrated
CACM	the reconstruction of binary patterns from their projections given the horizontal and vertical projections of a finite binary pattern f can we construct the original pattern f in this paper we give a characterization of patterns that are reconstructable from their projection three algorithms are developed to reconstruct both unambiguous and ambiguous patterns it is shown that an unambiguous pattern can be perfectly reconstructed in time m x n and that a pattern similar to an ambiguous pattern can also be constructed in time m x n where m n are the dimensions of the pattern frame
CACM	pattern width at a given angle that the pattern feature width as a function of angle possesses several possible interpretations is demonstrated in this paper which is a review of the width concept in pattern recognition and the geometrical concept itself the object of the work is to clarify how the word description can be made precise so that computer algorithms for feature extraction may be obtained the focus is on the theoretical subject matter the results consist of a set theoretic definition of width at angle a theorem relating it to the pattern boundary radius vector and descriptions of alternate widths all widths are calculated for an illustrative example graphical and tabular comparisons are given substantial variation in width at angle magnitude is found the principal conclusion is that the set theoretic width at angle is a useful pattern feature when it can be easily computed further investigation of the information contained in only part of a width function is recommended for cases where computation of width at angle is difficult
CACM	signature simulation and certain cryptographic codes three cyphers allegedly authored by thomas jefferson beale in 1822 have been the subject of intensive study for over 100 years generations of cryptanalysts have expended untold man years thus far without success attempting tode code them vast armies of fortune hunters and treasure seekers have devoted herculean labors to digging up the rolling hills of virginia trying to locate the promised bonanza the history of pertinent activities would fill volumes yet serious students of cryptography have always had nagging doubts about the cyphers authenticity it has been alleged that the known solution to cypher number two 115 73 24 818 37 52 49 i have deposited in the county of bedford about four miles from bufords in an excavation or vault with the aid of an unsanitized version of the declaration of independence was merely a superb imaginative and grandiose hoax perpetrated ages ago for whatever reasons modern computer technology could obviously perform signature analyses the process of encoding itself so as to yield new clues and deeper insights into their construction for the benefit of the uninitiated the encoding method used in the second cypher employs a specified document whose words are simply numbered consecutively and first letters of these words are sought out at random to match the letters of these words are sought out at random to match the letters of the clear text or message the sequence of numbers corresponding to these matches is then written down as the final code while primitive the process has the advantage of relative security until the source document becomes known at that moment the cypher can be decoded even by second graders the work now completed with the help of our univac 1108 includes numerous analytical studies of the beale cyphers and various types of simulations for example we have turned the entire process of simulated encoding by various schemes over to the machine and analyzed the signatures of these synthetic codes we have also encoded various messages by hand using different texts and a variety of methods to obtain their signatures these simulations provide convincing evidence that the signatures are both process and data dependent they indicate also very strongly that mr beales cyphers are for real and that it is merely a matter of time before someone finds the correct source document and locates the right vault in the common wealth of virginia
CACM	roots of matrix pencils algorithm r405
CACM	decision table translation algorithm r394
CACM	remarks on characteristic values and associated solutions of mathieus differential equation exponential integral and systems of hyperbolic p d e algorithms r352 r385 r392
CACM	bandsolve algorithm r195
CACM	least squares surface fit algorithm r176
CACM	squank algorithm c379
CACM	pseudo random numbers g5 algorithm c266
CACM	product type three point gauss legendre simpsons integration d1 algorithm a439
CACM	product type two point gauss legendre simpsons integration d1 algorithm a438
CACM	product type simpsons integration d1 algorithm a437
CACM	product type trapezoidal integration algorithm a436
CACM	trace driven modeling and analysis of cpu scheduling in multiprogramming system microscopic level job stream data obtained in a production environment by an event driven software probe is used to drive a model of a multiprogramming computer system the cpu scheduling algorithm of the model is systematically varied this technique called trace driven modeling provides an accurate replica of a production environment for the testing of variations in the system at the same time alterations in scheduling methods can be easily carried out in a controlled way with cause and effects relationships being isolated the scheduling methods tested included the best possible and worst possible methods the traditional methods of multiprogramming theory round robin first come first served etc and dynamic predictors the relative and absolute performances of these scheduling methods are given it is concluded that a successful cpu scheduling method must be preemptive and must prevent a given job from holding the cpu for too long a period
CACM	levels of language for portable software an increasing amount of software is being implemented in a portable form a popular way of accomplishing this is to encode the software in a specially designed machine independent language and then to map this language often using a macro processor into the assembly language of each desired object machine the design of the machine independent language is the key factor in this operation this paper discusses the relative merits of pitching this language at a high level or a low level and presents some comparative results
CACM	on the criteria to be used in decomposing systems into modules this paper discusses modularization as a mechanism for improving the flexibility ad comprehensibility of a system while allowing the shortening of its development time the effectiveness of a modularization is dependent upon the criteria used in dividing the system into modules a system design problem is presented and both a conventional and unconventional decomposition are described it is shown that the unconventional decompositions have distinct advantages for the goals outlined the criteria used in arriving at the decompositions are discussed the unconventional decomposition if implemented with the conventional assumption that a module consists of one or more subroutines will be less efficient in most cases an alternative approach to implementation which does not have this effect is sketched
CACM	a new method for the solution of the cauchy problem for parabolic equations an integral equation representation is given for parabolic partial differential equations when the equations are defined in unbounded domains as in the initial value cauchy problem the solution of the integral equation by the method of successive approximation has inherent advantages over other methods error bounds for the methods are of order h 3 2 and h 7 2 his the increment size depending on the finite difference approximations involved
CACM	a comparison of multivariate normal generators three methods for generating outcomes on multivariate normal random vectors with a specified variance covariance matrix are presented a comparison is made to determine which method requires the least computer execution time and memory space when utilizing the ibm 360 67 all methods use as a basis a standard gaussian random number generator results of the comparison indicate that the method based on triangular factorization of the covariance matrix generally requires less memory space and computer time than the other two methods
CACM	computer methods for sampling from the exponential and normal distributions corrigendum
CACM	weighted increment linear search for scatter tables a new linear search for hash tables whose increment step is a function of the key being addressed is presented comparisons with known methods are given in terms of efficiency and computation complexity in particular the new method applies to tables of size n 2 r it allows full table searching and practically eliminates primary clustering at a very low cost
CACM	a method for incrementally compiling languages with nested statement structure a method of incremental compilation is presented which applies especially to programming languages in which statements can be nested such as algol and pl i the method permits editing of the source language using a general purpose text editor and incremental processing of changes without frequent recompilation of entire routines the essential points of the method are 1 the syntax of the language is restricted insof ar as which constructs may occur on lines 2 an internal data structure called the skeleton is maintained to represent the statement structure 3 the recompilation is partially batched in the sense that recompilation of modified lines does not occur until the last of a set of editing commands has been received and 4 the parsing and compilation are factored into two parts that done on individual lines and that done globally to handle the relationships between the lines
CACM	index ranges for matrix calculi the paper describes a scheme for symbolic manipulation of index expressions which arise as a by product of the symbolic manipulation of expressions in the matrix calculi described by the authors in a previous paper this scheme attempts program optimization by transforming the original algorithm rather than the machine code the goal is to automatically generate code for handling the tedious address calculations necessitated by complicated data structures the paper is therefore preoccupied with indexing by position the relationship of indexing by name and indexing by position is discussed
CACM	dynamic partitioning for array languages the classical process of partitioning an array into subarrays is extended to a more useful array language operation various modes of partitioning are defined for different types of arrays so that subarrays may vary over the original array in a nearly arbitrary manner these definitions are motivated with several realistic examples to illustrate the value of partitioning for array languages of general interest is the data structure for partitioning this consists of dynamic tree structures which are used to derive and maintain the array control information these are described in sufficient detail to be of value in the design of other array languages the description presented in this paper is implemented in a new array language ol 2 currently under development at the university of illinois
CACM	comments on moorers music and computer composition
CACM	further comments on dijkstras concurrent programming control problem
CACM	a note on optimal doubly chained trees
CACM	additional results on key to address transform techniques a fundamental performance study on large existing formatted files
CACM	modified incomplete gamma function s14 algorithm a435
CACM	exact probabilities for r x c contingency tables g2 algorithm a434
CACM	an approximate method for generating symmetric random variables a method for generating values of continuous symmetric random variables that is relatively fast requires essentially no computer memory and is easy to use is developed the method which uses a uniform zero one random number source is based on the inverse function of the lambda distribution of turkey since it approximates many of the continuous theoretical distributions and empirical distributions frequently used in simulations the method should be useful to simulation practitioners
CACM	garbage collection for virtual memory computer systems in list processing there is typically a growing demand for space during program execution this paper examines the practical implications of this growth within a virtual memory computer system proposes two new garbage collection techniques for virtual memory systems and compares them with traditional methods by discussion and by simulation
CACM	the conversion of limited entry decision tables to optimal and near optimal flowcharts two new algorithms two new algorithms for deriving optimal and near optimal flowcharts from limited entry decision tables are presented both take into account rule frequencies and the time needed to test conditions one of the algorithms called the optimum finding algorithm leads to a flowchart which truly minimizes execution time for a decision table in which simple rules are already contracted to complex rules the other one called the optimum approaching algorithm requires many fewer calculations but does not necessarily produce the optimum flowchart the algorithms are first derived for treating decision tables not containing an else rule but the optimum approaching algorithm is shown to be equally valid for tables including such a rule both algorithms are compared with existing ones and are applied to a somewhat large decision table derived from a real case from this comparison two conclusions are drawn 1 the optimum approaching algorithm will usually lead to better results than comparable existing ones and will not require more but usually less computation time 2 in general the greater computation effort needed for applying the optimum finding algorithm will not be justified by the small reduction in execution time obtained
CACM	derived semantics for some programming language constructs the constructs of a simple programming language are introduced and described informally in terms of values and side effects a translator is defined which translates the language into flowcharts for a simple machine the action of the machine in executing a flowchart is defined a proof is constructed that the effect of translating and executing any program can be expressed solely in terms of the value and side effect of the program during the course of constructing the proof formal definitions of the concepts of value and side effect are derived in order to make the proof rigorous correctness of the implementation involves checking that the definitions derived in the step above are an acceptable formalization of the informal description given in the first step
CACM	a model for type checking most current programming languages treat computation over different classes of objects e g numbers strings labels and functions for correct compilation and execution the following question then arises is a program properly constructed so that its operations and operands are compatible the activity of answering this question is usually called type checking this paper attempts to isolate the notion of type checking and presents a partial solution to the type checking problem based on the notions of abstraction and application of functions in particular a program is mapped into an expression within a decidable subset of the lambda calculus which characterizes the type relations within the program and eliminates all other information the determination of the type wise correctness or incorrectness of the program is resolved by reducing its corresponding lambda calculus expression to one of two normal forms the constant correct for a type wise correct program or the constant error an application to type checking in algol 60 is made and the attendant problems faced for any notion of type checking are discussed
CACM	a highly parallel algorithm for approximating all zeros of a polynomial with only real zeros an algorithm is described based on newtons method which simultaneously approximates all zeros of a polynomial with only real zeros the algorithm which is conceptually suitable for parallel computation determines its own starting values so that convergence to the zeros is guaranteed multiple zeros and their multiplicity are readily determined at no point in the method is polynomial deflation used
CACM	algorithms to reveal properties of floating point arithmetic two algorithms are presented in the form of fortran subroutines each subroutine computes the radix and number of digits of the floating point numbers and whether rounding or chopping is done by the machine on which it is run the methods are shown to work on any reasonable floating point computer
CACM	a comparative study of computer programs for integrating differential equations a study comparing the performance of several computer programs for integrating systems of ordinary differential equations is reported the integration methods represented include multistep methods predictor correctors single step methods runge kutta and extrapolation methods both polynomial and rational the testing procedure is described together with the evaluation criteria applied a set of test problems on which the programs were tested is included in an appendix for the particular problems and criteria used in the investigation it was found that a program based on rational extrapolation showed the best performance
CACM	tableless date conversion algorithm r398
CACM	interpolation and smooth curve fitting based on local procedures e2 algorithm a433
CACM	aesthetics and the human factor in programming corrigendum
CACM	sorting by natural selection a family of sorting algorithms is proposed the members of which make fuller use of the memory space and thus yield longer sorted strings extensive simulation results are presented and various implications and further applications are discussed
CACM	conversion of decision tables by rule mask method without rule mask two algorithms for generating computer programs from decision tables are described the algorithms allow handling limited entry extended entry and mixed entry tables the algorithms are based on the rule mask method but need not have the masks at execution time they perform the logical operations immediately rather than at the end of the interpreting process execution time can be considerably reduced by instantly marking rules which are not applicable algorithms 1 and 2 or conditions which are already tested algorithm 2 the new algorithms combine to a certain degree the advantages of mask methods with those of tree methods
CACM	generating english discourse from semantic networks a system is described for generating english sentences from a form of semantic nets in which the nodes are word sense meanings and the paths are primarily deep case relations the grammar used by the system is in the form of a network that imposes an ordering on a set of syntactic transformations that are expressed as lisp functions the generation algorithm uses the information in the semantic network to select appropriate generation paths through the grammar the system is designed for use as a computational tool that allows a linguist to develop and study methods for generating surface strings from an underlying semantic structure initial finding with regard to form determiners such as voice form tense and mood some rules for embedding sentences and some attention to pronominal substitution are reported the system is programmed in lisp 1 5 and is available from the authors
CACM	integral equations of immunology the inversion of a particular integral equation of the first fredholm kind is the basic problem considered the strategy which yielded success consisted of three essential points 1 fit the known experimental data by a curve with properties which derive from properties of the as yet unknown function 2 stabilize the computation for the unknown function by using singular value decomposition 3 constrain the unknown function approximation since it represents a probability distribution to be nonnegative a number of test cases are presented one set of actual experimental data is analyzed with the procedures presented
CACM	computer methods for sampling from the exponential and normal distributions various methods are known for transforming uniformly distributed random numbers into exponentially and normally distributed quantities the most efficient ones are compared in terms of memory requirements and speed with some new algorithms a number of procedures convert taylor series expansions directly into sampling steps an approach which may be used for sampling from any continuous distribution for the exponential distribution a definite recommendation can be made whereas in the case of the normal distribution there remains a choice between slower and shorter algorithms and faster but space consuming methods
CACM	demand paging through utilization of working sets on the maniac ii a hardware implementation on the maniac ii computer of the working set model for demand paging as introduced by denning is discussed characteristics of the maniac ii are given along with a description of the basic demand paging scheme and the associate memory which has been added to the maniac ii hardware finally a description of the hardware design for implementation of the working set model is discussed and a specification of the actions taken under various conditions which may arise during the operation of the full working set model demand paging system is given
CACM	on fosters information storage and retrieval using avl trees
CACM	a controller for a braille terminal
CACM	comment on deadlock prevention method
CACM	the eigen problem of block tridiagonal matrices
CACM	a comparison of floating point summation methods
CACM	thinning algorithms on rectangular hexagonal and triangular arrays in this report three thinning algorithms are developed one each for use with rectangular hexagonal and triangular arrays the approach to the development of each algorithm is the same pictorial results produced by each of the algorithms are presented and the relative performances of the algorithms are compared it is found that the algorithm operating with the triangular array is the most sensitive to image irregularities and noise yet it will yield a thinned image with an overall reduced number of points it is concluded that the algorithm operating in conjunction with the hexagonal array has features which strike a balance between those of the other two arrays
CACM	solution of the matrix equation ax xb c f4 algorithm a432
CACM	computer routine for quadratic and linear programming problems h algorithm a431 a computer program based on lemkes complementary pivot algorithm is presented this can be used to solve linear and quadratic programming problems the program has been extensively tested on a wide range of problems and the results have been extremely satisfactory
CACM	automatic error analysis for determining precision the problem considered is that of evaluating a rational expression to within any desired tolerance on a computer which performs variable precision floating point arithmetic operations an automatic error analysis technique is given for determining directly from the results of a trial low precision interval arithmetic calculation just how much precision and data accuracy are required to achieve a desired final accuracy the technique given generalize easily to the evaluation of many nonrational expressions
CACM	a new approach to automatic scanning of contour maps the problem of automatic digitizing of contour maps is discussed the structure of a general contour map is analyzed and its topological properties are utilized in developing a new scanning algorithm the problem of detection and recognition of contour lines is solved by a two color labeling method it is shown that for maps containing normal contour lines only it suffices to distinguish between so called even and odd lines the tangency problem involved in practical scanning is discussed and a solution based on minimizing computer memory space and simplifying control program is suggested
CACM	file organization the consecutive retrieval property the consecutive retrieval property is an important relation between a query set and record set its existence enables the design of an information retrieval system with a minimal search time and no redundant storage some important theorems on the consecutive retrieval property are proved in this paper conditions under which the consecutive retrieval property exists and remain invariant have been established an outline for designing an information retrieval system based on the consecutive retrieval property is also discussed
CACM	cellular arrays for the solution of graph problems a cellular array is a two dimensional checkerboard type interconnection of identical modules or cells where each cell contains a few bits of memory and a small amount of combinational logic and communicates mainly with its immediate neighbors in the array the chief computational advantage offered by cellular arrays is the improvement in speed achieved by virtue of the possibilities for parallel processing in this paper it is shown that cellular arrays are inherently well suited for the solution of many graph problems for example the adjacency matrix of a graph is easily mapped onto an array each matrix element is stored in one cell of the array and typical row and column operations are readily implemented by simple cell logic a major challenge in the effective use of cellular arrays for the solution of graph problems is the determination of algorithms that exploit the possibilities for parallelism especially for problems whose solutions appear to be inherently serial in particular several parallelized algorithms are presented for the solution of certain spanning tree distance and path problems with direct applications to wire routing pert chart analysis and the analysis of many types of networks these algorithms exhibit a computation time that in many cases grows at a rate not exceeding log2 n where n is the number of nodes in the graph straightforward cellular implementations of the well known serial algorithms for these problems require about n steps and noncellular implementations require from n 2 to n 3 steps
CACM	immediate predominators in a directed graph h algorithm a430
CACM	localization of the roots of a polynomial c2 algorithm a429
CACM	a note on the generation of rosary permutations
CACM	comment on average binary search length
CACM	a bonus from van wijngaardens device
CACM	comment on the composition of semantics in algol 68
CACM	compiling fixed point multiplications
CACM	a model of memory contention in a paging machine this paper is concerned with certain aspects of contention for main memory resources in a multiprogrammed computer system operating under demand paging in the model presented the number of page frames of main memory allocated to a problem program varies in time these changes in memory configuration are represented explicitly in the model cpu requirements and page exception characteristics of program material being described statistically expressions for the distribution of the number of page frames allocated to an executing program the long run expected fraction of a programs execution time in a given number of page frames and the average execution interval of the multiprogrammed load are obtained it is pointed out heuristically and demonstrated numerically that an increase is obtain able in the average execution interval of the multiprogrammed load over that resulting from equal fixed partitioning of main memory
CACM	an environment for research in microprogramming and emulation the development of the research project in microprogramming and emulation at state university of new york at buffalo consisted of three phases the evaluation of various possible machines to support this research the decision to purchase one such machine which appears to be superior to the others considered and the organization and definition of goals for each group in the project each of these phases is reported with emphasis placed on the early results achieved in this research
CACM	an extensible editor for a small machine with disk storage a design philosophy for developing a sophisticated utility program is illustrated by the actual design and implementation of a text editor a versatile data structure is employed so that only a small number of programmed subroutines are necessary for all types of data manipulation such a data structure is described and its merits are illustrated by the ease with which powerful extensions can be implemented in terms of a few basic editing function
CACM	political redistricting by computer the problems of political redistricting are considered and a computer method for redistricting is presented criteria for acceptable redistricting are discussed including population equality compactness contiguity and preservation of natural and or political boundaries only nonpartisan criteria are considered using 1970 bureau of census population data specific results are given for the ten congressional districts in the state of missouri and for the seven st louis county council seats results from the use of the algorithm indicate the feasibility of political redistricting with the aid of a computer
CACM	generating parsers for affix grammars affix grammars are two level grammars which are similar to van wijngaardens two level grammars used in the definition of algol 68 affix grammars are shown by koster to be equal in power to van wijngaarden grammars they are much more suited to parsing than are the latter however koster the inventor of affix based on recursive procedures this paper presents a bottom up scheme for parsing them based on an extension of floyd production language fpl included is an algorithm similar to that of deremers for converting a large class of affix grammars into fpl the paper concludes by discussing briefly the applicabilities of the conversion algorithm and affix grammars in general and some possible extensions to kosters definition of affix grammars
CACM	computers and employment the relationship of computers and automation to employment is part of the more general relation of technological change to employment the most obvious effect is that increase in productivity due to technology can eliminate jobs technology affects the individual worker in the nature and amount of his work and in his attitudes toward that work technological change affects the occupational structure of the entire labor force because of the central importance of these effects the impact of technology has been the subject of extensive study by economists sociologists political scientists and psychologists even within a single discipline studies are often contradictory and conclusions are colored by political overtones we wish to delineate some of the issues and present arguments given to support different viewpoints
CACM	archaeology of computers   reminiscences 1945 1947 the period preceding the founding of acm was dominated by the first large computer eniac its characteristics described here foreshadow later developments
CACM	a western view of computer history many u s histories of the digital computer field have tended to be impersonal with heavy emphasis on eastern universities and commercial developments this article records the events of the early years in a personal way the people organizations technologies and computers of the 1945 55 period in the western part of the united statesare described as they happened
CACM	the plankalkul of konrad zuse a forerunner of todays programming languages plankalkul was an attempt by korrad zuse in the 1940s to devise a notational and conceptual system for writing what today is termed a program although this early approach to a programming language did not lead to practical use the plan is described here because it contains features that are standard in todays programming languages the investigation is of historical interest also it may provide insights that would lead to advancements in the state of the art using modern programming terminology the plankalkul is presented to the extent it has possible to reconstruct it from the published literature
CACM	ancient babylonian algorithms the early origins of mathematics are discussed emphasizing those aspects which seem to be of greatest interest from the standpoint of computer science a number of old babylonian tablets many of which have never before been translated into english are quoted
CACM	dynamic document processing the current role of computers in automatic document processing is briefly outlined and some reasons are given why the early promise of library automation and of the mechanization of documentation processes has not been fulfilled a new dynamic document environment is then outlined in which clustered files are searched and information is retrieved following an interactive user controlled search process methods are described for an automatic query modification based on user needs and for a continuous reorganization of the stored information as a function of earlier file processing and of normal collection growth the proposed procedures provide powerful tools for information retrieval and for the control of dynamic library collections in which new items are continually added and old ones are retired
CACM	computers and urban society this brief survey of the use of computers in urban society covers the broad range of activities found in any city the future scope of applications is limited only by the imagination and inventiveness of future system designers programmers analysts and decision makers the computer can be if properly used with respect for human dignity and civil liberty a significant factor in improving the efficiency of the urban process it is expected that the benefits of such computer usage will outweigh the costs and that we may look forward to an expansion of such usage
CACM	computers in the instructional process directions for research and development a survey is given of computer applications to the instructional process which suggests how the computer professional can contribute to effective educational systems
CACM	language analysis in the humanities the use of the computer in the language oriented humanities for exhaustive listing of detail as in indices and concordances is widespread and accepted as desirable the implications of the computer for a science of the humanities a science entailing gathering data for the construction and testing of models are neither widely recognized nor accepted this paper argues that the computers major role as to language analysis in the humanities will be the establishing of such a science thus for those areas of the humanities for which rigor and precision are necessary e g analyzing literature or teaching a student to write a composition the computer can be a critically important facilitator
CACM	a generational perspective of information system development system development is categorized from a generational point of view that parallels the commonly described computing system generations for each generation the scope of development projects and the technological world view of the system developer are examined
CACM	on the present and future of scientific computation a pessimistic forecast is given of what can be expected to happen in the application of computers to the physical sciences
CACM	the evolution of storage structures data base management systems have grown rapidly in their power and complexity over the 15 year history of data processing on commercially available computers the original concepts have split and new terms have been adopted to name and refer to these concepts the data structure diagram graphic technique is used to illustrate the splitting of the concepts and the structural relations which exist between these concepts at each point in the evolution
CACM	requirements for advanced programming systems for list processing list processing systems should be designed to facilitate production of large programs to manipulate large complex symbolic data stores this paper presents an overview of a number of system features which the author feels are important to improve the productivity of programmers working in such domains a system view it taken rather than focusing just on language features since algorithms must be not only coded in a language form but debugged modified made efficient and run on data because of this general framework the requirements specified are applicable to the design of advanced programming systems for a wide range of applications three aspects of programming systems are highlighted good interactive facilities programmable control structures and sophisticated data communication mechanisms interactive features are described to facilitate program composition entry testing debugging editing optimization and packaging implementation of a generalized environment structure model specified would allow programming of various control regimes including multiprocesses coroutines and backtracking alternative methods of procedure invocation required include invocation by pattern and by monitoring condition the need for extended data forms storage management and extensibility are stressed as is the duality of data retrieval and function evaluation syntax directed input and output of data would facilitate use of complex data stores
CACM	the production of better mathematical software some observations are made on steps to be taken toward the creation of better mathematical software these steps suggest the need for a coordinated effort and the creation of a center to focus activities in this area
CACM	programming languages history and future this paper discusses both the history and future of programming languages higher level languages some of the difficulties in writing such a history are indicated a key part of the paper is a tree showing the chronological development of languages and their interrelationships reasons for the proliferation of languages are given the major languages are listed with the reasons for their importance a section on chronology indicates the happenings of the significant previous time periods and the major topics of 1972 key concepts other than specific languages are discussed
CACM	programming systems and languages 1965 1975 in spite of impressive gains by pl i fortran and cobol remain the languages in which most of the worlds production programs are written and will remain so into the foreseeable future there is a great deal of theoretical interest in algol 68 and in extensible languages but so far at least they have had little practical impact problem oriented languages may very well become the most important language development area in the next five to ten years in the operating system area all major computer manufacturers set out to produce very ambitious multiprogramming systems and they all ran into similar problems a number of university projects though not directly comparable to those of the manufacturers have contributed greatly to a better understanding of operating system principles important trends include the increased interest in the development of system measurement and evaluation techniques and increased use of microprogramming for some programming system functions
CACM	the role of computer system models in performance evaluation models constitute a useful means of investigating computer system performance this paper examines the interrelationships between models and other methods for evaluating the performance of computer systems and establishes circumstances under which the use of a model is appropriate
CACM	operating system performance an overview of the current and future positions with respect to operating system performance is given while a great deal of information and a large number of models for subsystems have been developed gaps still exist in out knowledge because of the severe interactions between the various subsystems of an operating system an overall model of the total system must be developed to be able to analyze and design the performance aspects of an operating system although such total system designs are exceptional today it is projected that they will become increasingly more common and necessary in the near future such a design philosophy will clearly have a severe impact on the way we go about modularizing operating and computer systems
CACM	structured multiprogramming this paper presents a proposal for structured representation of multiprogramming in a high level language the notation used explicitly associates a data structure shared by concurrent processes with operations defined on it this clarifies the meaning of programs and permits a large class of time dependent errors to be caught at compile time a combination of critical regions and event variables enables the programmer to control scheduling of resources among competing processes to any degree desired these concepts are sufficiently safe to use not only within operating systems but also within user programs
CACM	on the interface between computers and data communications systems future systems that combine computers digital terminals and communications equipment present design optimization problems that require reconsideration of the traditional functional responsibilities of the respective subsystems several standard interfaces by means of which computers and digital terminals connect to the communications systems will be required when specifying these interfaces consideration must be given to problems of coordination synchronization error control signaling stream multiplexing and switch control in addition to minimizing the technological interdependence of specific subsystem designs a focus on some of the problems is obtained in a discussion of a detailed specification for a particular computer communications system interface
CACM	a view of computer architecture an attempt is made to predict the developments of the next 25 years in the field of computer architecture standardized inexpensive microcomputers on a single chip are predicted these will be used extensively to provide logical functions for noncomputational devices and incidentally for the design of superscale computers
CACM	toward a general theory of special functions a list of a number of natural developments for the field of algebraic manipulation is given then the prospects for a general theory of functions defined by ordinary differential equations are discussed the claim is made that recent developments in mathematics indicate that it should be possible to algorithmically generate many properties of solutions to differential equations such a theory is preferable to a less general effort to make algebraic manipulation systems knowledgeable about the usual special functions e g exponential hypergeometric
CACM	management science a view from nonlinear programming a brief history of integer and continuous nonlinear programming is presented as well as the current obstacles to practical use of these mathematical programming techniques it is forecast that the useful contributions to nonlinear programming actually made in the next few years are more likely to be consolidations than theoretical breakthroughs these contributions are likely to be the documentation of standard test problems construction of user oriented software and comparisons of currently known algorithms to demonstrate which techniques are best for specific problems
CACM	numerical mathematics and computer science numerical mathematics is viewed as the analysis of continuous algorithms four of the components of numerical mathematics are discussed these are foundations finite precision number systems computational complexity synthesis and analysis of algorithms analysis of error programs and program libraries
CACM	fix point approach to the theory of computation following the fix point theory of scott the semantics of computer programs are defined in terms of the least fix points of recursive programs this allows not only the justification of all existing verification techniques but also their extension to the handling in a uniform manner of various properties of computer programs including correctness termination and equivalence
CACM	toward an automata theory of brains a source of ideas for automata theory the study of the brain has been pushed aside in mathematical development of the theory this paper suggests the ways in which automata theory might evolve over the next 25 years if it is to contribute to an understanding of how the brain processes information
CACM	individualizing instruction in a generative cai tutor
CACM	computer science a vicious circle
CACM	calculation of fourier integrals algorithm r418
CACM	an integer programming problem algorithm r397
CACM	special series summation with arbitrary precision algorithm r393
CACM	random vectors uniform is solid angle algorithm r381
CACM	general random number generator algorithm r370
CACM	eigenvalues and eigenvectors of a real general matrix algorithm r343
CACM	complex error function algorithm c363
CACM	a sorting problem and its complexity a technique for proving min max norms of sorting algorithms is given one new algorithm for finding the minimum and maximum elements of a set with fewest comparisons is proved optimal with this technique
CACM	a starting method for solving nonlinear volterra integral equations of the second kind a fourth order starting method is given for volterra integral equations of the second kind and numerical examples are presented
CACM	computer assigned codes from verbal responses it is often desirable to convert verbal responses to multidigit codes this conversion is generally accomplished by clerk coders a study was conducted to test the feasibility of translating verbal descriptions to numerical codes in a computer program primary emphasis was placed on computerized construction of a reference file of verbal descriptions for use by the program the results of the study clearly show that such procedures are feasible
CACM	a boolean matrix method for the computation of linear precedence functions a modified version of bells boolean matrix method for the computation of linear precedence functions associated with a conflict free matrix of precedence relations is given this algorithm not only detects when the precedence functions do not exist but also provides an indication of why they do not exist so that corrective action can be taken if possible necessary and sufficient conditions for the existence of precedence functions are given the use of boolean matrices to prove the existence of precedence functions associated with classes of conflict free grammars is illustrated through an example
CACM	blocks a new data type for snobol4 a new data type called a block has been implemented for snobol4 a block is a three dimensional aggregate of characters in the form of a right parallelepiped best thought of as a three dimensional extension to a string the third dimension is used for overstriking blocks may be printed concatenated in any of three dimensions and merged on the basis of program defined connection points some blocks adapt in size and shape to their environment blocks and their operations are mainly used for composing printable output a variety of graphical problems including flowcharting bargraphs logic diagrams mathematical equation formation and text justification and preparation have been programmed on a printer in what appears to be an easy and natural way in addition to these somewhat specialized applications blocks appear to be a good general purpose device independent output formation mechanism especially suitable for nonnumerical work the concept of a block is largely language independent that is blocks require little in the way of specialized syntax and could readily be absorbed into the external structure of most programming languages
CACM	interference between communicating parallel processes various kinds of interference between communicating parallel processes have been examined by dijkstra knuth and others solutions have been given for the mutual exclusion problem and associated subproblems in the form of parallel programs and informal proofs of correctness have been given for these solutions in this paper a system of parallel processes is regarded as a machine which proceeds from one state s i e a collection of pertinent data values and process configurations to a next state s in accordance with a transition rule s    s a set of such rules yields sequences of states which dictate the systems behavior the mutual exclusion problem and the associated subproblems are formulated as questions of inclusion between sets of states or of the existence of certain sequences a mechanical proof procedure is shown which will either verify prove the correctness of or discredit prove the incorrectness of an attempted solution with respect to any of the interference properties it is shown how to calculate transition rules from the partial rules by which the individual processes operate the formation of partial rules and the calculation of transition rules are both applicable to hardware processes as well as to software processes and symmetry between processes is not required
CACM	a proposal to establish a pseudo virtual memory via writable overlays many computer systems solve executable storage size problems for large programs by using overlays however it appears that no one overlay scheme contains a well balanced combination of the most useful capabilities which are found in various existing techniques a proposal is presented which utilizes several of the best capabilities from existing schemes and is complemented by several additional features e g writable overlays the writable overlay capability provides a virtual memory effect although the programmer may still be required to design the overlay configuration since overlay structuring is a complex task several tools including a graphic display are included in the proposal in order to aid the programmer in the design the content of overlays is briefly discussed and it is noted that many of the details of the final overlay configuration may be decided after the fact
CACM	on the optimization of performance of time sharing systems by simulation a simulation model of a time sharing system with a finite noncontiguous store and an infinite auxiliary store is used to study the variation of system parameters such as store size number of jobs allowed to execute simultaneously job scheduling algorithm etc the effects of these variations on a measure of system performance is used to ascertain which of the parameters controllable by the job scheduling algorithm including the scheduling itself require optimization and which of the parameters not normally controllable by the scheduling algorithm have a marked effect on system performance system performance is based upon the mean cost of delay to all jobs processed it is shown that significant improvements in the measure of system performance can be obtained by using variable time slice techniques and by selecting the optimum round robin cycle time it appears that these features would benefit from optimization whereas other parameters controllable by the scheduling algorithm affect system performance in a predictable manner and would not benefit from optimization features not normally under the control of the scheduling algorithm can also have a marked effect on the measure of performance in particular supervisor overheads the size of the store and the speed of the cpu a comparison is made between the results of the simulation model and two analytical equations for quantum oriented nonpreemptive time sharing systems the comparison is found to be very favorable
CACM	curriculum recommendations for graduate professional programs in information systems the need for education related to information systems in organizations is discussed and a curriculum is proposed for graduate professional programs in universities at the masters level material necessary for such programs is identified and courses incorporating it are specified detailed course descriptions are presented program organization discussed and implementation questions considered
CACM	hu tucker minimum redundancy alphabetic coding method z algorithm a428
CACM	fourier cosine integral d1 algorithm a427
CACM	merge sort algorithm m1 algorithm a426
CACM	generation of random correlated normal variables g5 algorithm a425
CACM	clenshaw curtis quadrature d1 algorithm a424
CACM	the optimality of winograds formula
CACM	minimax nonlinear approximation by approximation on subsets
CACM	fast finite difference solution of biharmonic problems setting the reynolds number equal to zero in a method for solving the navier strokes equations numerically results in a fast numerical method for biharmonic problems the equation is treated as a system of two second order equations and a simple smoothing process is essential for convergence an application is made to a crack type problem
CACM	implementing clenshaw curtis quadrature ii computing the cosine transformation in a companion paper to this i methodology and experiences the automatic clenshaw curtis quadrature scheme was described and how each quadrature formula used in the scheme requires a cosine transformation of the integrand values was shown the high cost of these cosine transformations has been a serious drawback in using clenshaw curtis quadrature two other problems related to the cosine transformation have also been trouble some first the conventional computation of the cosine transformation by recurrence relation is numerically unstable particularly at the low frequencies which have the largest effect upon the integral second in case the automatic scheme should require refinement of the sampling storage is required to save the integrand values after the cosine transformation is computed this second part of the paper shows how the cosine transformation can be computed by a modification of the fast fourier transform and all three problems overcome the modification is also applicable in other circumstances requiring cosine or sine transformations such as polynomial interpolation through the chebyshev points
CACM	implementing clenshaw curtis quadrature i methodology and experience clenshaw curtis quadrature is a particularly important automatic quadrature scheme for a variety of reasons especially the high accuracy obtained from relatively few integrand values however it has received little use because it requires the computation of a cosine transformation and the arithmetic cost of this has been prohibitive this paper is in two parts a companion paper ii computing the cosine transformation shows that this objection can be overcome by computing the cosine transformation by a modification of the fast fourier transform algorithm this first part discusses the strategy and various error estimates and summarizes experience with a particular implementation of the scheme
CACM	a technique for software module specification with examples this paper presents an approach to writing specifications for parts of software systems the main goal is to provide specifications sufficiently precise and complete that other pieces of software can be written to interact with the piece specified without additional information the secondary goal is to include in the specification no more information than necessary to meet the first goal the technique is illustrated by means of a variety of examples from a tutorial system
CACM	mux a simple approach to on line computing an on line system operating as part of a normal batch system for the cdc 6600 computer is described the system which required one man year for initial software implementation although basically simple provides the necessary elements to input and modify files submit them for batch execution and provide results at the users terminal a multiplexer designed and developed as part of the project cost one man year for design and checkout and 16 000 for parts and fabrication all aspects of the system are described including design criteria implementation cost overhead and user reactions
CACM	the multics virtual memory concepts and design as experience with use of on line operating systems has grown the need to share information among system users has become increasingly apparent many contemporary systems permit some degree of sharing usually sharing is accomplished by allowing several users to share data via input and output of information stored in files kept in secondary storage through the use of segmentation however multics provides direct hardware addressing by user and system programs of all information independent of its physical storage location information is stored in segments each of which is potentially sharable and carries its own independent attributes of size and access privilege here the design and implementation considerations of segmentation and sharing in multics are first discussed under the assumption that all information resides in large segmented main memory since the size of main memory on contemporary systems is rather limited it is then shown how the multics software achieves the effect of a large segmented main memory through the use of the honeywell 645 segmentation and paging hardware
CACM	an improved index sequential access method using hashed overflow the index sequential access method isam is one of the most important file management systems used with moveable head disk devices this study investigates the use of an unconventional method of treating overflow records the method is to use hashing techniques to allocate space for such records if certain conditions are satisfied this is superior to the conventional isam method of chaining the overflow records via linked list techniques these conditions are long overflow chains with significant overflow lack of tight disk space constraints record keys which are small compared to the total record size and significant use of the file in the index as opposed to the sequential mode using hashed overflow the time to locate a record is dependent not on the total volume of overflow records as in conventional isam but on the percentage use of space dedicated to overflow records
CACM	a comment on the double chained tree
CACM	a note on cheneys nonrecursive list compacting algorithm
CACM	linear equation solver f4 algorithm a423
CACM	minimal spanning tree h algorithm a422
CACM	complex gamma function with error control s14 algorithm a421
CACM	matrix computations with fortran and paging the efficiency of conventional fortran programs for matrix computations can often be improved by reversing the order of nested loops such modifications produce modest savings in many common situations and very significant savings for large problems run under an operating system which uses paging
CACM	complex gamma function with error control an algorithm to compute the gamma function and log gamma function of a complex variable is presented the standard algorithm is modified in several respects to insure the continuity of the function value and to reduce accumulation of round off errors in addition to computation of function values this algorithm includes an object time estimation of round off errors experimental data with regard to the effectiveness of this error control are presented a fortran program for the algorithm appears in the algorithms section of this issue
CACM	computers and society a proposed course for computer scientists the purpose of this paper is to describe a course concerned with both the effects of computers on society and the responsibilities of computer scientists to society the impact of computers is divided into five components political economic cultural social and moral the main part of the paper defines each component and presents examples of the relevant issues in the remaining portions the possible formats for such a course are discussed a topic by topic outline is given and a selected set of references is listed it is hoped that the proposal will make it easier to initiate courses on this subject
CACM	an implemented graph algorithm for winning shannon switching games in this tutorial paper a computer program which wins shannon switching games is described since these games are played on graphs the program is a good example of the implementation of graph algorithms the two players in a shannon switching game connect and cut have nonsimilar goals either connect cut or the player moving first is guaranteed the existence of a winning strategy the simple strategy explained in this paper is valid in all three cases in fact the major routines never need to know whether the computer is connect or cut
CACM	hidden lines elimination for a rotating object a method is presented of determining which parts of three dimensional objects are visible and which are invisible when the objects are rotated about some axis this paper describes a polygon comparison scheme in which the relationships of two polygons can be classified into tree types and also discusses how the relationship is changed for each pair of polygons under rotation about some axis a rotation table is defined for each pair of polygons which remains fixed as long as rotation is about one axis and provides a means of rapidly determining the visible and hidden line relationship between two polygons additional work must be done to extend this approach to simultaneous rotation about several axes
CACM	an experimental laboratory for pattern recognition and signal processing an interactive computer controlled scanning and display system has been in operation at the ibm thomas j watson research center for three years the system includes two flying spot scanners and a tv camera specially interfaced to a process control digital computer dot mode and vector displays analog input and output facilities and a variety of other experimental equipment the system design and programming support are described and typical applications in scanner control optical character recognition and image processing are presented
CACM	a system for interprocess communication in a resource sharing computer network a system of communication between processes in a time sharing system is described and the communication system is extended so that it may be used between processes distributed throughout a computer network the hypothetical application of the system to an existing network is discussed
CACM	on the implementation of security measures in information systems the security of an information system may be represented by a model matrix whose elements are decision rules and whose row and column indices are users and data items respectively a set of four functions is used to access this matrix at translation and execution time distinguishing between data dependent and data independent decision rules enables one to perform much of the checking of security only once at translation time rather than repeatedly at execution time the model is used to explain security features of several existing systems and serves as a framework for a proposal for general security system implementation within todays languages and operating systems
CACM	properties of the working set model a programs working set w t t at time t is the set of distinct pages among the t most recently referenced pages relations between the average working set size the missing page rate and the interreference interval distribution may be derived both from time average definitions and from ensemble average statistical definitions an efficient algorithm for estimating these quantities is given the relation to lru least recently used paging is characterized the independent reference model in which page references are statistically independent is used to assess the effects to interpage dependencies on working set size observations under general assumptions working set size is shown to be normally distributed
CACM	a study of storage partitioning using a mathematical model of locality both fixed and dynamic storage partitioning procedures are examined for use in multiprogramming systems the storage requirement of programs is modeled as a stationary gaussian process experiments justifying this model are described by means of this model dynamic storage partitioning is shown to provide substantial increases in storage utilization and operating efficiency over fixed partitioning
CACM	a comparative analysis of disk scheduling policies five well known scheduling policies for movable head disks are compared using the performance criteria of expected seek time system oriented and expected waiting time individual i o request oriented both analytical and simulation results are obtained the variance of waiting time is introduced as another meaningful measure of performance showing possible discrimination against individual requests then the choice of a utility function to measure total performance including system oriented and individual request oriented measures is described such a function allows one to differentiate among the scheduling policies over a wide range of input loading conditions the selection and implementation of a maximum performance two policy algorithm are discussed
CACM	synchronization of communicating processes formalization of a well defined synchronization mechanism can be used to prove that concurrently running processes of a system communicate correctly this is demonstrated for a system consisting of many sending processes which deposit messages in a buffer and many receiving processes which remove messages from that buffer the formal description of the synchronization mechanism makes it very easy to prove that the buffer will neither overflow nor underflow that senders and receivers will never operate on the same message frame in the buffer nor will they run into a deadlock
CACM	a hardware architecture for implementing protection rings protection of computations and information is an important aspect of a computer utility in a system which uses segmentation as a memory addressing scheme protection can be achieved in part by associating concentric rings of decreasing access privilege with a computation this paper describes hardware processor mechanisms for implementing these rings of protection the mechanisms for implementing these rings of protection the mechanisms allow cross ring calls and subsequent returns to occur without trapping to the supervisor automatic hardware validation of references across ring boundaries is also performed thus a call by a user procedure to a protected subsystem including the supervisor is identical to a call to a companion user procedure the mechanisms of passing and referencing arguments are the same in both cases as well
CACM	an operating system based on the concept of a supervisory computer an operating system which is organized as a small supervisor and a set of independent processes are described the supervisor handles i o with external devices the file and directory system schedules active processes and manages memory handle errors and provides a small set of primitive functions which it will execute for a process a process is able to specify a request for a complicated action on the part of the supervisor usually a wait on the occurrence of a compound event in the system by combining these primitives into a supervisory computer program the part of the supervisor which executes these programs may be viewed as a software implemented supervisory computer the paper develops these concepts in detail outlines the remainder of the supervisor and discusses some of the advantages of this approach
CACM	the design of the venus operating system the venus operating system is an experimental multiprogramming system which supports five or six concurrent users on a small computer the system was produced to test the effect of machine architecture on complexity of software the system is defined by a combination of microprograms and software the microprogram defines a machine with some unusual architectural feature the software exploits these features to define the operating system as simply as possible in this paper the development of the system is described with particular emphasis on the principles which guided the design
CACM	tenex a paged time sharing system for the pdp 10 tenex is a new time sharing system implemented on dec pdp 10 augmented by special paging hardware developed at bbn this report specifies a set of goals which are important for any time sharing system it describes how the tenex design and implementation achieve these goals these include specifications for a powerful multiprocess large memory virtual machine intimate terminal interaction comprehensive uniform file and i o capabilities and clean flexible system structure although the implementation described here required some compromise to achieve a system operational within six months of hardware checkout tenex has met its major goals and provided reliable service at several sites and through the arpa network
CACM	average binary search length for dense ordered lists corrigendum
CACM	reconstruction of pictures from their projections corrigendum
CACM	music and computer composition the problem discussed is that of simulating human composition of western popular music by computer and some relevant theories of music and harmony are given problems with this kind of program and several schemes that are known not to work are discussed several previous computer compositions are discussed including the illiac suite a program to generate short melody fragments was written to simulate some of the aspects of human composition five samples of its output are presented and discussed it was discovered that although the fragments show many of the characteristics of popular melodies they have a strangely alien sound it is theorized that this is because the relevant probabilities which would discriminate against unfamiliar sequences were not used
CACM	hidden line plotting program j6 algorithm a420
CACM	zeros of a complex polynomial c2 algorithm a419
CACM	dynamic microprogramming processor organization and programming corrigendum
CACM	maximum computing power and cost factors in the centralization problem a simple analysis of some computer economic factors involved in comparing multimachine installations versus large single machine installations is given and a mathematical model is derived to assist policy decisions
CACM	optimizing binary trees grown with a sorting algorithm items can be retrieved from binary trees grown with a form of the algorithm quicksort in an average time proportional to log n where n is the number of items in the tree the binary trees grown by this algorithm sometimes have some branches longer than others therefore it is possible to reduce the average retrieval time by restructuring the tree to make the branches as uniform in length as possible an algorithm to do this is presented the use of this algorithm is discussed and it is compared with another which restructures the tree after each new item is added
CACM	preliminary report on a system for general space planning a computer language and a set of programs within that language are described which allow the formulating and solving of a class of space planning problems the language is an extension of algol and includes means to represent spaces and objects to manipulate them and to test the resulting arrangements according to a variety of constraints the algorithms used to solve problems expressed in this language rely on heuristic programming both the language and the search algorithms are detailed
CACM	a proposal for a computer based interactive scientific community because of the problems created by the explosion of papers in the mathematical sciences and the drawbacks that this places on research it is suggested that a tree of all mathematical results and terminology be maintained in a multiterminal computer system users of the system can store in the computer an updated file of their current knowledge and on selecting a paper to read they can obtain from the computer the minimum subtree of theorems required to bring them from what they already know to the background knowledge which the paper assumes under certain conditions means are also provided for the contribution of useful comments by the readers of a work and for interaction between commentators and with the author this paper describes how the system can be organized and the role required of readers writers and commentators
CACM	unitary symmetric polynomials z algorithm r391
CACM	in situ transposition of a rectangular matrix f1 algorithm c380
CACM	calculation of fourier integrals d1 algorithm a418
CACM	ordering  f  f  f  f x when f x is positive monotonic
CACM	quadratic programming for nonlinear regression a quadratic programming algorithm is described for use with the magnified diagonal method of nonlinear regression with linear constraints the regression method is published in jacm july 1970
CACM	muse a model to understand simple english muse is a computer model for natural language processing based on a semantic memory network like that of quillians tlc muse from a model to understand simple english processes english sentences of unrestricted content but somewhat restricted format the model first applies syntactic analysis to eliminate some interpretations and then employs a simplified semantic intersection procedure to find a valid interpretation of the input while the semantic processing is similar to tlcs the syntactic component includes the early use of parse trees and special purpose rules the relational triple notation used during interpretation of input is compatible with muses memory structures allowing direct verification of familiar concepts and the addition of new ones muse also has a repertoire of actions which range from editing and reporting the contents of its own memory to an indirect form of question answering examples are presented to demonstrate how the model interprets text resolves ambiguities adds information to memory generalizes from examples and performs various actions
CACM	optimizing the polyphase sort corrigendum
CACM	teacher student authored cai using the newbasic system the pedagogical advantages of a general purpose interactive system called newbasic catalyst are discussed newbasic catalystincorporates an advanced implementation of basic system level interactive features and a general capability for extension through user oriented function attachment application of this last feature to provide a flexible cai scan capability is illustrated an example of interaction at the system level shows how students can mix the advantages of independent or solo mode computing with those of guided or dual mode interaction preliminary experience with the system in an urban secondary school setting is discussed
CACM	a crt editing system a test editing and manipulation program is described the program operates from low cost cathode ray tube entry and display stations with keyboard and 13 function buttons applications potential economy of operation and some aspects of implementation are discussed
CACM	use of the hough transformation todetect lines and curves in pictures hough has proposed an interesting and computationally efficient procedure for detecting lines in pictures this paper points out that the use of angle radius rather than slope intercept parameters simplifies the computation further it also shows how the method can be used for more general curve fitting and gives alternative interpretations that explain the source of its efficiency
CACM	on shrinking binary picture patterns a parallel processing algorithm for shrinking binary patterns to obtain single isolated elements one for each pattern is presented this procedure may be used for counting patterns on a matrix and a hardware implementation of the algorithm using large scale integrated technology is envisioned the principal features of this method are the very small window employed two by two elements the parallel nature of the process and the possibility of shrinking any pattern regardless of the complexity of its configuration problems regarding merging and disconnection of patterns during the process as well as the determination of the maximum number of steps necessary to obtain a single isolated element from a pattern are reviewed and discussed an analogy with a neural network description in terms of mcculloch pitts neurons is presented
CACM	pictorial pattern recognition and the phase problem of x ray crystallography the availability of interactive three dimensional computer graphics systems coupled to powerful digital computers encourages the development of algorithms adapted to this environment pictorial pattern recognition techniques make possible a number of approaches to x ray structure determination based on molecular model building i e the use of chemical information to frame structural hypotheses which can computationally be tested and refined by reference to the experimental data application of standard pattern recognition algorithms is hindered by the fact that the cross correlation between a model and the correct structure cannot be computed because of a fundamental incompleteness in the measured data however it is possible to compute an upper bound to such a cross correlation a simple example demonstrates that this information can be the basis of a technique for structure determination that can make effective use of an interactive graphics system model building by cross correlations has intrinsic advantages over usual crystallographic techniques based on the autocorrelation or patterson function especially for large structures this is significant for crystallography of biological macromolecules hasbeen and will continue to be a field of intense interest
CACM	procedures for natural spline interpolation e1 algorithm a472
CACM	exponential integrals s13 algorithm a471
CACM	linear systems with almost tridiagonal matrix f4 algorithm a470
CACM	a data definition and mapping language a data definition language i sa declarative computer language for specifying data structures most data definition languages concentrate on the declaration of logical data structures with little concern for how these structures are physically realized on a computer system however the need for data definition languages which describe both the logical and physical aspects of data is increasingly apparent such languages will be a key systems as well as in advanced data management systems and distributed data bases this paper reviews past work in the data definition language for describing both logical and physical aspects of data applications of these generalized data definition languages are also discussed
CACM	curriculum recommendations for undergraduate programs in information systems the need for education related to information systems in organizations is discussed and a curriculum is proposed for an undergraduate program material necessary for such programs is identified and courses incorporating it are specified detailed course descriptions are presented program organization and a problems of implementation are discussed
CACM	solving the biharmonic equation in a square a direct versus a semidirect method two methods for solving the biharmonic equation are compared one method is direct using eigenvalue eigenvector decomposition the other method is iterative solving a poisson equation directly at each iteration
CACM	an algorithm for the approximate solution of wiener hopf integral equations an explicit approximate solution is given for an equation where it is assumed that the classical wiener hopf technique may be applied it is furthermore assumed that fourier transforms are known explicitly the approximate solution depends on two positive parameters
CACM	a recurrence scheme for converting from one orthogonal expansion into another a generalization of a scheme of hamming for converting a polynomial pn x into a chebyshev series is combined with a recurrence scheme of clenshaw for summing any finite series whose terms satisfy a three term recurrence formula
CACM	tree structured programs
CACM	comment on brents scatter storage algorithm
CACM	a note on subexpression ordering in the execution of arithmetic expressions a counterexample to the supposed optimality of an algorithm for generating schedules for trees of tasks with unequal execution times is presented a comparison with the critical path heuristic is discussed
CACM	arithmetic overa finite field a1 algorithm a469
CACM	algorithm for automatic numerical integration over a finite interval d1 algorithm a468
CACM	matrix transposition in place f1 algorithm a467
CACM	four combinatorial algorithms g6 algorithm a466
CACM	students t frequency s14 algorithm a465
CACM	eigenvalues of a real symmetric tridiagonal matrix f2 algorithm a464
CACM	experiments with an automatic theorem prover havingpartial ordering inference rules automatic theorem provers need to be made much more efficient with this in mind slagle has shown how the axioms for partial ordering can be replaced by built in inference rules when using a particular theorem proving algorithm based upon hyper resolution and paramodulation the new rules embody the transitivity of partial orderings and the close relationship between predicates a program has been developed using a modified version of these rules this new theorem prover has been found to be very powerful for solving problems involving partial orderings this paper presents a detailed description of the program and a comprehensive account of the experiments that have been performed with it
CACM	a scan conversion algorithm with reduced storage requirements most graphics systems using a raster scan output device crt or hardcopy maintain a display file in the xy or random scan format scan converters hardware or software must be provided to translate the picture description from the xy format to the raster format published scan conversion algorithms which are fast will reserve a buffer area large enough to accommodate the entire screen on the other hand those which use a small buffer area are slow because they require multiple passes through the xy display file the scan conversion algorithm described here uses a linked list data structure to process the lines of the drawing in strips corresponding to groups of scan lines a relatively small primary memory buffer area is used to accumulate the binary image for a group of scan lines when this portion of the drawing has been plotted the buffer is reused for the next portion because of the list processing procedures used only a single pass through the xy display file is required when generating the binary image and only a slight increase in execution time over the fully buffered core results results slow that storage requirements can be reduced by more than 80 percent while causing less than a 10 percent increase in execution time
CACM	adaptive correction of program statements corrigendum
CACM	a parser generating system for constructing compressed compilers this paper describes a parser generating system pgs currently in use on the cdc 6500 computer at purdue university the pgs is a fortran coded compiler in the input translation grammar each bnf syntactic rule corresponds to a possibly empty code generator realizable as an assembly language fortran or algol subroutine that is called whenever that syntactic rule is applied in the parse of a program typical one pass compilers constructed by the pgs translate source programs at speeds approaching 14 000 cards per minute for an xpl compiler the parser program and its tables currently occupy 288 words of 60 bit core memory of which 140 words are parsing table entries and 82 words are links to code generators
CACM	dynamic verification of operating system decisions dynamic verification of a decision implies that every time the decision is made there is a consistency check performed on the decision using independent hardware and software the dynamic verification of operating system decisions is used on the prime system being designed and constructed at the university of california berkeley prime is an experimental time sharing which is to have the properties of continuous availability data privacy and cost effectiveness the technique of dynamic verification allows the construction of an operating system which does not make certain decisions improperly even in the presence of a single hardware or software fault furthermore multiple faults lead to unreliable operation only if the faults happen to reinforce each other on prime dynamic verification is used to ensure that one users information cannot become available to another user gratuitously even in the presence of a single hardware or software fault the amount of additional hardware and software required for dynamic verification can be modest
CACM	the programmer as navigator
CACM	algorithms scale1 scale2 and scale3 for determination of scales on computer generated plots j6 algorithm a463
CACM	bivariate normal distribution s15 algorithm a462
CACM	cubic spline solutions to a class of functional differential equations d2 algorithm a461
CACM	calculation of optimum parameters for alternating direction implicit procedures d3 algorithm a460
CACM	the elementary circuits of a graph h algorithm a459
CACM	discrete linear l1 approximation by interval linear programming e2 algorithm a458
CACM	addendum to a multiple precision division algorithm
CACM	control structures in illiac iv fortran as part of an effort to design and implement a fortran compiler on the illiac iv an extended fortran called ivtran has been developed this language provides a means of expressing data and control structures suitable for exploiting illiac iv parallelism this paper reviews the hardware characteristics of the illiac and singles out unconventional features which could be expected to influence language and compiler design the implications of these features for data layout and algorithm structure are discussed and the conclusion is drawn that data allocation rather than code structuring is the crucial illiac optimization problem a satisfactory method of data allocation is then presented language structures to utilize this storage method and express parallel algorithms are described
CACM	using page residency to select the working set parameter dennings method for selecting the working set parameter which uses interreference intervals is examined several omissions in his model are noted and new assumptions are introduced to overcome these omissions using this modified model denings results on page residency are rederived and reconsidered for selecting the working set parameter
CACM	a class of dynamic memory allocation algorithms anew dynamic memory allocation algorithm the fibonacci system is introduced this algorithm is similar to but seems to have certain advantages over the buddy system a generalization is mentioned which includes both of these systems as special cases
CACM	a note on the confinement problem this note explores the problem of confining a program during its execution so that it cannot transmit information to any other program except its caller a set of examples attempts to stake out the boundaries of the problem necessary conditions for a solution are stated and informally justified
CACM	general performance analysis of key to address transformation methods using an abstract file concept this paper presents a new approach to the analysis of performance of the various key to address transformation methods in this approach the keys in a file are assumed to have been selected from the key space according to a certain probabilistic selection algorithm all files with the same number of keys selected from this key space will be suitably weighted in accordance with the algorithm and the average performance of the transformation methods on these files will be used as the potential of these methods using this analysis methods with the same overall performance can be classified and key distributions partial to certain transformations can be identified all this can be done analytically the approach is applied to a group of transformation methods using files whose keys are selected randomly
CACM	a model and stack implementation of multiple environments many control and access environment structures require that storage for a procedure activation exist at times when control is not nested within the procedure activated this is straightforward to implement by dynamic storage allocation with linked blocks for each activation but rather expensive in both time and space this paper presents an implementation technique using a single stack to hold procedure activation storage which allows retention of that storage for durations not necessarily tied to control flow the technique has the property that in the simple case it runs identically to the usual automatic stack allocation and deallocation procedure applications of this technique to multitasking coroutines backtracking label valued variables and functional arguments are discussed in the initial model a single real processor is assumed and the implementation assumes multiple processes coordinate by passing control explicitly to one another a multiprocessor implementation requires only a few changes to the basic technique as described
CACM	multiple terminals under user program control in a time sharing environment user written programs on the dartmouth time sharing system can communicate with many remote terminals simultaneously and can control the interactions between these terminals such programs can be written using standard input and output instructions in any language available on the system this paper describes how this multiple terminal facility was implemented without requiring any changes in the system executive or in any of the systems compilers or interpreters
CACM	localization of the roots of a polynomial algorithm r429
CACM	hidden line plotting program algorithm r420
CACM	a sparse matrix package algorithm r408
CACM	generation of permutations in lexicographic order algorithm r323
CACM	finding all cliques of an undirected graph algorithm a457
CACM	routing problem algorithm a456
CACM	analysis of skew representations of the symmetric group algorithm a455
CACM	sard kernels for certain bivariate cubatures an error analysis for some bivariate cubatures is given the remainders are obtained by the use of sard kernels numerical results and computer graphs are given for some of the kernel functions
CACM	reversible execution
CACM	a simple technique for structured variable lookup a simple technique for the symbol table lookup of structured variables based on simple automata theory is presented the technique offers a deterministic solution to a problem which is currently handled in a nondeterministic manner in pl i and cobol compilers
CACM	empirical working set behavior the working set model for program behavior has been proposed in recent years as a basis for the design of scheduling and paging algorithms although the words working set are now commonly encountered in the literature dealing with resource allocation there is a dearth of published data on program measurements in the hope that workers in the field might find experimental evidence upon which to substantiate and base theoretical work
CACM	design of tree structures for efficient querying a standard information retrieval operation is to determine which records in a data collection satisfy a given query expressed in terms of data values the process of locating the desired responses can be represented by a tree search model this paper poses an optimization problem in the design of such trees to serve a well specified application the problem is academic in the sense that ordinarily the optimal tree cannot be implemented by means of practical techniques on the other hand it is potentially useful for the comparison it affords between observed performance and that of an intuitively attractive ideal search procedure as a practical application of such a model this paper considers the design of a novel tree search scheme based on a bit vector representation of data and shows that essentially the same algorithm can be used to design either an ideal search tree or a bit vector tree an experimental study of a small formatted file illustrates the concepts
CACM	evaluation and selection of file organization a model and system this work first discusses the factors that affect file data base organization performance an elusive subject and then presents a methodology a model and a programmed system to estimate primarily total storage costs and average access time of several file organizations given a specific data base query characterization and device related specifications based on these estimates an appropriate file structure may be selected for the specific situation the system is a convenient tool to study file structures and to facilitate as much as possible the process of data base structure design and evaluation
CACM	information theory applied to the conversion of decision tables to computer programs using ideas from information theory this paper develops a heuristic algorithm that converts a limited entry decision table to a tree structured computer program with near minimum average processing time the method is applicable to any limited entry decision table and does not require that actions have single rules or that the cost of testing conditions be equal it is thus more general than the previously published heuristic algorithms compared to the optimal algorithm of reinwald and soland this algorithm is easy to code and takes a much smaller translation time it is thus felt that it is more useful in practice the algorithm is well suited for manual conversion of decision tables to flowcharts
CACM	computational algorithms for closed queueing networks with exponential servers methods are presented for computing the equilibrium distribution of customers in closed queueing networks with exponential servers expressions for various marginal distributions are also derived the computational algorithms are based on two dimensional iterative techniques which are highly efficient and quite simple to implement implementation considerations such as storage allocation strategies and order of evaluation are examined in some detail
CACM	a generalization of avl trees a generalization of avl trees is proposed in which imbalances up to triangle shape is a small integer an experiment is performed to compare these trees with standard avl trees and with balanced trees on the basis of mean retrieval time of amount of restructuring expected and on the worst case of retrieval time it is shown that by permitting imbalances of up to five units the retrieval time is increased a small amount while the amount of restructuring required is decreased by a factor of ten a few theoretical results are derived including the correction of an earlier paper and are duly compared with the experimental data reasonably good correspondence is found
CACM	on the capabilities of while repeat and exit statements a well formed program is defined as a program in which loops and if statements are properly nested and can be entered only at their beginning a corresponding definition is given for a well formed flowchart it is shown that a program is well formed if and only if it can be written with if repeat and multi level exit statements for sequence control it is also shown that if while and repeat statements with single level exit do not suffice it is also shown that any flowcharts can be converted to a well formed flowchart by node splitting practical implications are discussed
CACM	inductive methodsfor proving properties of programs there are two main purposes in this paper first clarification and extension of known results about computation of recursive programs with emphasis on the difference between the theoretical and practical approaches second presentation and examination of various known methods for proving properties of recursive programs discussed in detail are two powerful inductive methods computational induction and structural induction including examples of their applications
CACM	localization of the roots of a polynomial algorithm r429
CACM	hu tucker minimum redundancy alphabetic coding method algorithm r428
CACM	clenshaw curtis quadrature algorithm r424
CACM	graph plotter algorithm r412
CACM	an efficient prime number generator algorithm r357
CACM	complex gamma function algorithm r404 c404
CACM	the complex method for constrained optimization e4 algorithm a454
CACM	gaussian quadrature formulas for bromwichs integral d1 algorithm a453
CACM	enumerating combinations of m out of n objects g6 algorithm a452
CACM	chi square quantiles g1 algorithm a451
CACM	rosenbrock function minimization e4 algorithm a450
CACM	petri nets and speed independent design petri nets are investigated as one method of modeling speed independent asynchronous circuits a study of circuit realizations of petri nets leads to a demonstration of their usefulness in modeling speed independent operation this usefulness is emphasized by the design of a speed independent processor from modules developed in the investigation of petri net implementation
CACM	fen an axiomatic basis for program semantics a formal system is presented which abstracts the notions of data item function and relation it is argued that the system is more suitable than set theory or its derivatives for the concise and accurate description of program semantics it is shown how the system can be used to build composite data types out of simper ones with the operations of rowing structuring and uniting it is also demonstrated that completely new primitive types can be introduced into languages through the mechanism of singleton data types both deterministic and nondeterministic functions are shown to be definable in the system it is described how the local environment can be modeled as a data item and how imperative statements can be considered functions on the environment the nature of recursive functions is briefly discussed and a technique is presented by which they can be introduced into the system the technique is contrasted with the use of the paradoxical combinator y the questions of local and global environments and of various modes of function calling and parameter passing are touched upon the theory is applied to the proof of several elementary theorems concerning the semantics of the assignment conditional and iterative statements an appendix is included which presents in detail the formal system governing webs and fen the abstractions used informally in the body of the paper
CACM	a learning program which plays partnership dominoes a learning program has been written is basic to play four player partnership dominoes because dominoes is a game of incomplete information the program uses somewhat different principles of artificial intelligence from those used in programs for games of complete information such as checkers chess and go the program was constructed to use a strategy signature table which classifies board situations through the interactions of game parameters each entry in the table contains adaptively determined weights indicating the advi sability of various strategies once chosen a strategy then employs probability analysis and linear polynomial evaluation to choose a move our program wins approximately two thirds of its games in tournament situations and has defeated championship players
CACM	minimal spanning tree algorithm r422
CACM	hidden line plotting program algorithm r420
CACM	difsub for solution of ordinary differential equations algorithm c407
CACM	solution of linear programming problems in 0 1 variables h1 algorithm a449
CACM	equivalence between and or graphs and context free grammars
CACM	multiple exits from a loop without the goto
CACM	computer science seminars for undergraduates
CACM	curriculum recommendations for graduate professional programs in information systems recommended addendum on information systems administration an addendum to the report of the acm curriculum committee on computer education for management is proposed the proposed addendum is to include in the curriculum a course on information systems administration it is important for two reasons 1 the systems designer must understand the administrative framework in which he must operate to work effectively and 2 an important objective of the curriculum recommendations is to prepare the future manager of the computer activity it is felt that the importance of these two reasons justifies the addition of the recommended course the course is outlined in the format of the original report
CACM	teaching about programming this paper presents the goals and organization of a course about programming designed to provide entering students in a graduate program with a cultural enrichment in their professional lives the students are expected to have taken at least two programming courses prior to this one and therefore to be familiar with at least two programming languages both as students and users teaching someone how to program is similar to teaching him to play a musical instrument neither skill can be taught they must be learned however the teacher still serves several vital purposes to present a set of rules for producing well formed utterances to offer numerous demonstrations of his own skill and to function as an involved critic finally the teacher is the source of information about the process in which the student is involved
CACM	the distribution of a program in primary and fast buffer storage a virtual memory computer system with a fast buffer cache memory between primary memory and the central processing unit is considered the optimal distribution of a program between the buffer and primary memory is studied using the programs lifetime function expressions for the distribution of a program which maximizes the useful fraction of the cost time integral of primary and fast buffer storage are obtained for swapping and nonswapping buffer management policies
CACM	mixed solutions for the deadlock problem mixtures of detection avoidance and prevention provide more effective and practical solutions to the deadlock problem than any one of these alone the individual techniques can be tailored for subproblems of resource allocation and still operate together to prevent deadlocks this paper presents a method based on the concept of the hierarchical operating system for constructing appropriate mixtures and suggests appropriate subsystems for the most frequently occurring resource allocation problems
CACM	coko iii the cooper koz chess program coko iii is a chess player written entirely in fortran on the ibm 360 65 coko iii plays a minimal chess game at the rate of 2 sec cpu time per move with a level close to lower chess club play a selective tree searching procedure controlled by tactical chess logistics allows a deployment of multiple minimal game calculations to achieve some optimal move selection the tree searching algorithms are the heart of cokos effectiveness yet they are conceptually simple in addition an interesting phenomenon called a tree searching catastrophe has plagued cokos entire development just as it troubles a human player standard exponential growth is curbed to a large extent by the definition and trimming of the fischer set a clear distinction between tree pruning and selective tree searching is also made representation of the chess environment is described along with a strategical preanalysis procedure that maps the lasker regions specific chess algorithms are described which could be used as a command structure by anyone desiring to do some chess program experimentation a comparison is made of some mysterious actions of human players and coko iii
CACM	a note on information organization and storage since the logical structure of a data base can be represented by a tree or graph it is quite natural for us to view the process of designing a data base as that of constructing a tree or a graph a general method for constructing such a tree or a graph is provided there are three important elements in this general construction method namely a set of binary relations an algorithm for constructing subsets of a set and an algorithm for selecting an element from the given set of objects the use of different relations and algorithms results in different information structures as list tree ring etc thus the problem of information organization and storage is reduced to that of defining relations and formulating algorithms under a given set of constraints the results presented may be valuable to designers as useful design concepts and may serve as a basis for developing a formal theory on the subject
CACM	managing the computer resource a stage hypothesis based on the study of expenditures for data processing a descriptive stage hypothesis is presented it is suggested that the planning organizing and controlling activities associated with managing the computer resource will change in character over a period of time and will evolve in patterns roughly correlated to four stages of the computer budget stage i computer acquisition stage ii intense system development stage iii proliferation of controls and stage iv user service orientation each stage is described and related to individual tasks for managing the computer resource
CACM	computer photocomposition of technical text in computer assisted typesetting by means of photocomposition special problems arise in highly technical material such as mathematical formulas new solutions to several of these problems have been devised in the information system of the american institute of physics they include the representation of special characters foreign alphabets mathematical symbols etc not available on input keyboards or on the photocomposer the generation of such symbols e g by overprinting the precise positioning of accent marks floating diacritics line breaks i e words or formulas placed partly at the end of one line and partly at the beginning of the next and certain aspects of error correction
CACM	cubic spline solutions to fourth order boundary value problems the cubic spline approximation to the fourth order differential equation y p x y q x y r x y t x is shown to reduce to the solution of a five term recurrence relationship for some special cases the approximation is shown to be simply related to a finite difference representation with a local truncation error of order y 720 delta 8
CACM	least squares piecewise cubic curve fitting the matrices involved in a linear least squares formulation are determined for the problem of fitting piecewise cubic functions those possessing a continuous derivative to arrays of planar data
CACM	number of multiply restricted partitions a1 algorithm a448
CACM	efficient algorithms for graph manipulation h algorithm a447 efficient algorithms are presented for partitioning a graph into connected components biconnected components and simple paths the algorithm for partitioning of a graph into simple paths is iterative and each iteration produces a new path between two vertices already on paths the start vertex can be specified dynamically if v is the number of vertices and e is the number of edges each algorithm requires time and space proportional to max v e when executed on a random access computer
CACM	threaded code the concept of threaded code is presented as an alternative to machine language code hardware and software realizations of it are given in software it is realized as interpretive code not needing an interpreter extensions and optimizations are mentioned
CACM	the development of decision tables via parsing of complex decision situations a new parsing technique is proposed which allows parsing based only on syntactical characteristics of the decision problem it requires a description of the problem in decision grid chart format and allows the development of decision tables within defined limits by avoiding or at least minimizing repetition of conditions and actions in the resulting tables
CACM	optimum data base reorganization points in certain data base organization schemes the cost per access may increase due to structural inefficiencies caused by updates by reorganizing the data base the cost per access may be reduced however the high cost of a reorganization prohibits frequent reorganizations this paper examines strategies for selecting the optimum reorganization points
CACM	a computer generated aid for cluster analysis a computer generated graphic method which can be used in conjunction with any hierarchical scheme of cluster analysis is described and illustrated the graphic principle used is the representation of the elements of a data matrix of similarities or dissimilarities by computer printed symbols of character overstrikes of various shades of darkness where a dark symbol corresponds to a small dissimilarity the plots applied to a data matrix before clustering and to the rearranged matrix after clustering show at a glance whether clustering brought forth any distinctive clusters a well known set of data consisting of the correlations of 24 psychological tests is used to illustrate the comparison of groupings by four methods of factor analysis and two methods of cluster analysis
CACM	adapting optimal code generation for arithmetic expressions to the instruction sets available on present day computers
CACM	on the near optimality of the shortest latency time first drum scheduling discipline for computer systems in which it is practical to determine the instantaneous drum position a popular discipline for determining the sequence in which the records are to be accessed is the so called shortest latency time first sltf discipline when a collection of varying length records is to be accessed from specified drum positions it is known that the sltf discipline does not necessarily minimize the drum latency time however we show that the total time to access the entire collection for any sltf schedule is never as much as a drum revolution longer than a minimum latency schedule
CACM	synchronizing processors with memory content generated interrupts implementations of the lock unlock method of synchronizing processors in a multiprocessor system usually require uninterruptable memory pause type instructions an interlock scheme called read interlock which does not require memory pause instructions has been developed for a dual dec pdp 10 system with real time requirements the read interlock method does require a special read interlock instruction in the repertoire of the processors and a special read interlock cycle in the repertoire of the memory modules when a processor examines a lock a memory location with a read interlock instruction it will be interrupted if the lock was already set examining a lock immediately sets it if it was not already set this event sequence is a read interlock cycle writing into a lock clears it having the processor interrupted upon encountering a set lock instead of branching is advantageous if the branch would have resulted in an effective interrupt
CACM	minimizing wasted space in partitioned segmentation a paged virtual memory system using a finite number of page sizes is considered two algorithms for assigning pages to segments are discussed both of these algorithm are simple to implement the problem of choosing the page sizes to minimize the expected value of total wasted space in internal fragmentation and in a page table per segment is then solved for a probability density function of segment size which may be expressed as a convex combination of erlang densities
CACM	efficient multiprogramming resource allocation and accounting although sometimes thought of as only a component of time sharing operation multiprogramming can involve broader questions of resource allocation since fairness is not required to meet a response criterion in a multiprogrammed system it may serve maximal resource use to be unfair for example by holding an input output channel idle for a program while it completes a small amount of processor usage enabling further use of the channel several applications of this principle are given and it is suggested that a multiprogramming executive might dynamically adjust its allocation algorithms to gain efficiency allocation of resources is closely connected to accounting for those resources raising the problems of repeatability minimal uncharged overhead and relative weighting of charges for dependent resources since weightings may depend on allocation algorithms these are not arbitrary accounting parameters often the only repeatable accounting is one which omits an extensive overhead will be paid and should multiprogramming prove efficient overcharges will result multiprogramming turns on allocation of the memory resource essential to control of other resources the general suggestions for allocation and accounting are applied to this question and some details provided for the case of a monitor which controls a virtual memory machine
CACM	a practical approach to managing resources and avoiding deadlocks resource scheduling and allocation can be expensive with regard to time and space in multiprogramming or time sharing environments involving large numbers of tasks and resources with conflicting requirements detection and or prevention of deadlocks can require massive amounts of additional overhead if efficient usage of resources is to be maintained a resource management program is described which uses linked lists along with other techniques to overcome a large portion of this overhead the program which is currently running as part of a large scale general purpose operating system keeps resources relatively active but does not detect or prevent all deadlocks in its implemented state certain changes which would permit more comprehensive levels of deadlock prevention detection at additional cost have not been incorporated in the running system due to the infrequency of deadlock situations
CACM	wylbur an interactive text editing and remote job entry system wylbur is a comprehensive system for manipulating all kinds of text such as computer programs letters and manuscripts using typewriter terminals connected to a computer it has facilities for remote job entry and retrieval as well as facilities for text alignment and justification a powerful method for addressing text by content is provided this paper describes the external appearance of wylbur as well as its internal structure a short description of the major features of orvyl a general purpose time sharing system which operates in conjunction with wylbur is also included
CACM	a comment on the practical aspects of computer science education
CACM	another comment on computer music
CACM	concerning music and computer composition in computational linguistics
CACM	reflection free permutations rosary permutations and adjacent transposition algorithms
CACM	a sparse matrix package algorithm r408
CACM	exact solution of linear equations using residue arithmetic algorithm r406
CACM	increasing the efficiency of quicksort algorithm r402
CACM	minit algorithm for linear programming algorithm r333
CACM	minit algorithm for linear programming algorithm r333
CACM	maxflow algorithm r324
CACM	coulomb wave functions algorithm r300
CACM	a nonrecursive list moving algorithm an efficient nonrecursive algorithm is given for moving any lisp type list in particular the algorithm requires no storage other than the new nodes into which the list is to be moved and no additional bits per node for marking the algorithm runs in time proportional to the number of nodes in the list the original list structure is destroyed as it is moved
CACM	an array grammar programming system a package of fortran programs has been developed that permits a user to interactively design and test array grammars the user can control the rule selection procedure in a derivation or parse using weighted programming matrices he also has a choice of instance selection schemes raster random parallel examples are given involving array languages consisting of simple geometrical patterns as well as a language of neuron pictures
CACM	minimal event node network of project precedence relations a procedure for constructing a minimal event node network to represent a set of precedence relations without parallel activities is presented a minimal event node network is an event node network in which both the number of nodes and the number of arcs are the minima to preserve the given precedence relations counterexamples are given to show that the algorithm presented by a c fisher j s liebman and g l nemhauser 1968 produces event node networks which are not minimal since our procedure includes the set covering problem the time required may grow exponentially with the number of given activities
CACM	hierarchical storage in information retrieval a probabilistic analysis is employed to determine the effect of hierarchical storage organizations on information retrieval operations the data storage hardware is assumed to consist on n levels of linearly connected memory hardware with increasing data access times and increasing data storage capabilities a system might for example consist of fast semiconductor memory computer core memory extended core storage disk memory and data cells equations are derived to predict the effect of such a system on data access times using sequential files random access files and structured files employing multiple hierarchical linked lists
CACM	some comments on the use of ambiguous decision tables and their conversion to computer programs this paper comments upon recently published work on decision table translation using methods similar to the rule mask technique the applicability of these methods under various possible conventions on overall table meaning is discussed and it is argued that there is a place both for the multi rule and the single rule or action set convention in decision tale usage
CACM	programming by questionnaire an effective way to use decision tables programming by questionnaire combines aspects of decision table programming and general purpose programming by using decision tables to construct an application program through the selection of certain source statements from a predefined file it is proposed that programming by questionnairies a useful compromise between general and special purpose programming for a significant class of large scale problems the elements of the approach are discussed an existing application is described
CACM	on the problem of communicating complex information the nature of the difficulty involved in communicating mathematical results between scientists using a computer based information retrieval system is examined the problem is analyzed in terms of psychological and information processing processes and what turns out to be a vicious circle of effects is described these include ways of augmenting written natural language by various notational and linguistic devices the exhibition of the structure inherent in the information we are communicating and a sophisticated interactive system controlled by computer
CACM	greatest common divisor of n integers and multipliers algorithm c386
CACM	ten subroutines for the manipulation of chebyshev series c1 algorithm a446
CACM	the design implementation and evaluation of a working set dispatcher the behavior of a computer system is largely dependent upon the algorithms employed to allocate the system resources to the processes competing for them recent research in time sharing paging systems has developed the working set model for program behavior and are source allocation strategy based on this model has been proposed two implementations along these principles have been reported but it seems that in neither case have further results been announced this report discusses the design and implementation of a dispatcher based on the working set principle presents data to permit analysis of its behavior and indicates future directions of research on methods of controlling a computer system
CACM	a region coloring technique for scene analysis a method of converting a picture into a cartoon or map whose regions correspond to differently textured regions is described texture edges in the picture are detected and solid regions surrounded by these usually broken edges are colored in using a propagation process the resulting map is cleaned by comparing the region colors with the textures of the corresponding regions in the picture and also by merging some regions with others according to criteria based on topology and size the method has been applied to the construction of cloud cover maps from cloud cover pictures obtained by satellites
CACM	some approaches to best match file searching the problem of searching the set of keys in a file to find a key which is closest to a given query key is discussed after closest in terms of a metric on the the key space is suitably defined three file structures are presented together with their corresponding search algorithms which are intended to reduce the number of comparisons required to achieve the desired result these methods are derived using certain inequalities satisfied by metrics and by graph theoretic concepts some empirical results are presented which compare the efficiency of the methods
CACM	a statistical study of the accuracy of floating point number systems this paper presents the statistical results of tests of the accuracy of certain arithmetic systems in evaluating sums products and inner products and analytic error estimates for some of the computations the arithmetic systems studied are 6 digit hexadecimal and 22 digit binary floating point number representations combined with the usual chop and round modes of arithmetic with various numbers of guard digits and with a modified round mode with guard digits in a certain sense arithmetic systems differing only in their use of binary or hexadecimal number representations are shown to be approximately statistically equivalent inaccuracy further the usual round mode with guard digits is shown to be statistically superior in accuracy to the usual chop mode in all cases save one the modified round mode is found to be superior to the chop mode in all cases
CACM	asymmetric memory hierarchies a study is presented of some of the system implications of memory hierarchies in which the backing or secondary store has a very small read time relative of both the time required for writing and to the read time of conventional backing storage devices several analytic models are introduced and it is shown that such hierarchies may operate in ways which differ from those of more conventional hierarchies in particular it is shown that it may not be necessary to multiprogram in such a situation in the past backing storage devices have been roughly symmetric with respect to their read and write times this situation may not continue as several devices are currently under development which may have a very small read time write time ratio this study places particular emphasis on one such system the rca read write holographic optical memory
CACM	implementation of high level language machine computing machines which directly execute the statements of a high level language have been proposed in the past this report describes the actual implementation of such a machine it is a computer whose machine language is apl the machine is fully operational and correctly executes almost all of the apl operations on scalars vectors and arrays the machine automatically allocates memory executes statements calls functions converts numbers from one type to another checks subscripts and automatically detects many types of programmer errors
CACM	binary pattern reconstruction from projections z algorithm r445
CACM	binary pattern reconstruction from projections z algorithm a445
CACM	an algorithm for extracting phrases in a space optimal fashion z algorithm a444
CACM	graduate education the ph d glut
CACM	on harrisons substring testing technique
CACM	gray code and the   sign sequence when  f  f  f  f x is ordered
CACM	design and implementation of a diagnostic compiler for pl i pl c is a compiler for a dialect for pl i the design objective was to provide a maximum degree of diagnostic assistance in a batch processing environment for the most part this assistance is implicit and is provided automatically by the compiler the most remarkable characteristic of pl c is its perseverance it completes translation of every program submitted and continues execution until a user established error limit is reached this requires that the compiler repair errors encountered during both translation and execution and the design of pl c is dominated by this consideration pl c also introduces several explicit user controlled facilities for program testing to accommodate these extensions to pl i without abandoning compatibility with ibm compiler pl c permits pseudo comments  constructions whose contents can optionally be considered either source test or comment in spite of the diagnostic effort pl c is a fast and efficient processor it effectively demonstrates that compilers can provide better diagnostic assistance than is customarily offered even when a sophisticated source language is employed and that this assistance need not be prohibitively costly
CACM	the effects of multiplexing on a computer communications system a study is made of the way in which asynchronous time division multiplexing changes the stochastic nature of the arrival process from a user to the computer and consequently affects the performance of a time shared computer communications system it is concluded that while for certain values of system parameters there is noticeable improvement in the performance of the computer model in the sense that time shared scheduling delays are reduced these improvements are offset by the transmission delays imposed by multiplexing so that there may be little or no change in the computer communications system performance analytical and simulation results are based on the model of the computer communications system being an m d 1 queue the multiplexor in tandem with a single exponential server the computer analytical results include a general description of the output process of an m d 1 queue and the conditions under which this output process is approximately poisson
CACM	telecommunications using a front end minicomputer the use of a front end minicomputer to provide varied remote terminal access to a large scale computer is considered the problems of embedding telecommunications i o within an operating system are discussed and it is shown how the decentralization of intelligence acquired by front end processing vastly simplifies the problem a specific implementation is discussed with emphasis on the main processor minicomputer link the hardware software implementation the effect of the main processor operating system and an assessment of the advantages over a hard wired line controller
CACM	common phrases and minimum space text storage a method for saving storage space for text strings such as compiler diagnostic messages is described the method relies on hand selection of a set of text strings which are common to one or more messages these phrases are then stored only once the storage technique gives rise to a mathematical optimization problem determine how each message should use the available phrases to minimize its storage requirement this problem is nontrivial when phrases which overlap exist however a dynamic programming algorithm is presented which solves the problem in time which grows linearly with the number of characters in the text algorithm 444 applies to this paper
CACM	a computer science course program for small colleges the acm subcommittee on small college programs of the committee on curriculum in computer science cccs was appointed in 1969 to consider the unique problems of small colleges and universities and to make recommendations regarding computer science programs at such schools this report authorized by both the subcommittee and cccs supplies a set of recommendations for courses and necessary resources implementation problems are discussed specifically within the constraints of limited faculty and for the purposes of satisfying a wide variety of objectives detailed description of four courses are given suggestions are made for more advanced work and an extensive library list is included
CACM	solution of the transcendental equation w exp w x c5 algorithm a443
CACM	properties of the working set model corrigendum
CACM	an overview of the ispl computer system design this paper explores the advantages of the concurrent design of the language operating system and machine via microcode to create an interactive programming laboratory it describes the synergistic effect that the freedom to move and alter features from one of these domains to another has had on the design of this system which has not been implemented this freedom simplified both incremental compilation and the systems addressing structure and centralized the communication mechanisms enabling the construction of hierarchical subsystems it also suggested an important new concept for operating systems separation of the scheduling from the maintenance functions in resource allocation this separation enables incorporation of new scheduling algorithms decision of what to do without endangering the system integration correctly performing the scheduling decisions
CACM	a software design and evaluation system a critical failure of current software system design and implementation methodology is that the performance of a proposed design is not evaluated before it is actually implemented in this paper the reasons for this failure are explored and a new methodology which overcomes many of the difficulties is proposed a system which integrates performance evaluation with design and implementation is described this system is based on a simple high level language which is used to describe the evolving system at all stages of its development the source language description is used as direct input to performance analysis and simulation routines using the performance information obtained from these routines as feedback the problems which adversely affect performance are detected early enough so that they can be corrected without costly major reimplementation of the proposed system
CACM	reducing the retrieval time of scatter storage techniques a new method for entering and retrieving information in a hash table is described the method is intended to be efficient if most entries are looked up several times the expected number of probes to look up an entry predicted theoretically and verified by monte carlo experiments is considerably less than for other comparable methods if the table is nearly full an example of a possible fortran implementation is given
CACM	automatic error bounds for simple zeros of analytic functions the cauchy ostrowski theorem on convergence of newton iterates for an analytic function in one variable is extended to include computational errors using complex interval arithmetic several numerical examples are given for polynomials with real and complex roots and one example for the bessel function of the first kind
CACM	a theory of discrete patterns and their implementation in snobol4 the notion of a discrete pattern is formalized and certain properties deduced a pattern is shown to be a generalization of a formal language algorithms for implementing the kinds of patterns in snobol4 are given the general approach is to create in so far as possible a bottom up parse from a top down specification
CACM	the use of grammatical inference for designing programming languages both in designing a new programming language and in extending an existing language the designer is faced with the problem of deriving a natural grammar for the language we are proposing an interactive approach to the grammar design problem wherein the designer presents a sample of sentences and structures as input to a grammatical inference algorithm the algorithm then constructs a grammar which is a reasonable generalization of the examples submitted by the designer the implementation is presently restricted to a subclass of operator precedence grammars but a second algorithm is outlined which applies to a larger class of context free grammars
CACM	representation of contours ad regions for efficient computer search a novel computer searchable representation for the three basic pictorial features contour maps region coverage and line structures is described the representation which has practical storage requirements provides a rapid mean of searching large files for data associated with geometric position as well as with attribute value an application of this representation to handling terrain information illustrates its utility the algebraic properties of the data structure make it computationally easy to determine whether a point lies within a closed boundary compute the area contained by a closed boundary generate the closed boundary representing the union or intersection of two closed boundaries and determine the neighboring boundaries to a point and the minimum distances between them and the point
CACM	normal deviate s14 algorithm a442
CACM	random deviates from the dipole distribution g5 algorithm a441
CACM	a multidimensional monte carlo quadrature with adaptive stratified sampling d1 algorithm a440
CACM	mutual recursion in algol 60 using restricted compilers
CACM	a note on when to chain overflow items within a direct access table
CACM	the practical aspect of computer science education discussion
CACM	reduction of a band symmetric generalized eigenvalue problem an algorithm is described for reducing the generalized eigenvalue problem ax lambda bx to an ordinary problem in case a and b are symmetric band matrices with b positive definite if n is the order of the matrix and m the bandwidth the matrices a and b are partitioned into m by m blocks and the algorithm is described in terms of these blocks the algorithm reduces the generalized problem to an ordinary eigenvalue problem for a symmetric band matrix c whose bandwidth is the same as a and b the algorithm is similar to those of rutishauser and schwartz for the reduction of symmetric matrices to band form the calculation c requires order mn 2 operation the round off error in the calculation of c is of the same order as the sum of the errors at each of the n m steps of the algorithm the latter errors being largely determined by the condition of b with respect to inversion
CACM	variable precision exponentiation a previous paper presented an efficient algorithm called the recomputation algorithm for evaluating a rational expression to within any desired tolerance on a computer which performs variable precision arithmetic operations the recomputation algorithm can be applied to expressions involving any variable precision operations having o 10  p sum ei error bounds where p denotes the operations precision and ei denotes the error in the operations ith argument this paper presents an efficient variable precision exponential operation with an error bound of the above order other operations such as log sin and cos which have simple series expansions can be handled similarly
CACM	adaptive correction of program statements a method of analyzing statements in a programming language which can tolerate a considerable inaccuracy in their specification is proposed this method involves principles at present mainly confined to studies in the area of artificial intelligence such as feature extraction approximate tree matching and strategy improvement by feedback from the matching process a pilot program incorporating the principles is described and preliminary operating results are presented a final section surveys further principles which are currently being investigated
CACM	on the time required for a sequence of matrix products this paper discusses the multiplication of conformable sequences of row vectors column vectors and square matrices the minimum time required to evaluate such products on ordinary serial computers as well as parallel computers is discussed algorithms are presented which properly parse such matrix sequences subject to the constraints of the machine organization
CACM	protection in programming languages linguistic mechanisms which can be used to protect one subprogram from anothers malfunctioning are described function producing functions and various type tagging schemes are considered an attempt is made to distinguish between access limitation and authentication
CACM	the reallocation of hash coded tables when the space allocation for a hash coded table is altered the table entries must be rescattered over the new space a technique for accomplishing this rescattering is presented the technique is independent of both the length of the table and the hashing function used and can be utilized in conjunction with a linear reallocation of the table being rescattered moreover it can be used to eliminate previously flagged deletions from any hash coded table or to change from one hashing method to another the efficiency of the technique is discussed and theoretical statistics are given
CACM	a queuing model of a multiprogrammed computer with a two level storage system the results are presented of an analysis of a probabilistic model of a multiprogrammed computer system with a two level storage system in which there is sequential dependency of accesses between the devices expressions are obtained for the long run probability that both the cpu and each of the storage devices are busy some numerical results are given which quantify the gains in cpu utilization obtainable by multiprogramming in the presence of this type of storage system
CACM	a heuristic approach to inductive inference in fact retrieval systems heuristic procedures are presented which have been developed to perform inferences by generalizing from available information the procedures make use of a similarity structure which is imposed on the data base using nonnumerical clustering algorithms they are implemented in a model fact retrieval system which uses a formal query language and a property list data structure a program of experiments is described wherein the procedures are used with test data bases which are altered by deleting part of the data and by purposely introducing false data it is found that the system can infer the correct response under a variety of conditions involving incomplete and inconsistent data
CACM	routing problem algorithm r456
CACM	merge sort algorithm r426
CACM	hidden line plotting program algorithm r420
CACM	a gaussian pseudo random number generator algorithm 488
CACM	exact cumulative distribution of the kolmogorov smirnov statistic for small samples algorithm a487
CACM	an exponential method for the solution of systems of ordinary differential equations an explicit coupled single step method for the numerical solution of initial value problems for systems of ordinary differential equations is presented the method was designed to be general purpose in nature but to be especially efficient when dealing with stiff systems of differential equations it is in general second order except for the case of a linear system with constant coefficients and linear forcing terms in that case the method is third order it has been implemented and put to routine usage in biological applications where stiffness frequently appears with favorable results when compared to a standard fourth order runge kutta implementation computation time required by this method has ranged from comparable for certain nonstiff problems to better than two orders of magnitude faster for some highly stiff systems
CACM	a graph formulation of a school scheduling algorithm the problem classically titled the examination schedule problem takes various forms in the literature most of these formulations can be presented in the terminology of classical network theory one such formulation is given a nondirected network partition its nodes into a minimal number of subsets such that no two members of the same subset are connected by anarc an obvious lower limit to this number is the size of the largest strongly connected subgraph kirchgassner proved that an upper limit is this size plus one one logical extension of the previous work is the introduction of variable length examinations where w i is the number of periods for exam i the object of this paper is to generalize the definition of largest strongly connected subgraph to include the weighting of nodes to present an approximate algorithm which usually finds the largest strongly connected subgraph and to discuss the application of this algorithm to the solution of school scheduling and exam scheduling problems
CACM	computer generation of gamma random variates with non integral shape parameters when the shape parameter a is integral generating gamma random variables with a digital computer is straightforward there is no simple method for generating gamma random variates with non integral shape parameters a common procedure is to approximately generate such random variables by use of the so called probability switch method another procedure which is exact is due to johnk this paper presents a rejection method for exactly generating gamma random variables when a is greater than 1 the efficiency of the rejection method is shown to be better than the efficiency of johnks method the paper concludes that when a is non integral the following mix of procedures yields the best combination of accuracy and efficiency 1 when a is less than 1 use johnks method 2 when 1 is less than a and a is less than 5 use the rejection method 3 when a is greater than 5 use the probability switch method
CACM	a comparison of list schedules for parallel processing systems the problem of scheduling two or more processors to minimize the execution time of a program which consists of a set of partially ordered tasks is studied cases where task execution times are deterministic and others in which execution times are random variables are analyzed it is shown that different algorithms suggested in the literature vary significantly in execution time and that the b schedule of coffman and graham is near optimal a dynamic programming solution for the case in which execution times are random variables is presented
CACM	an analytic model of the hasp execution task monitor the hasp execution task monitor periodically rearranges the os 360 dispatching chain to give tasks preemptive execution priority in inverse order to that of their cpu utilization history the effect is to keep the i o bound tasks active and to prevent cpu bound tasks from locking out other tasks this paper develops a simple model of the execution task monitor and employs it to study the effectiveness of the monitor in improving system performance a modified strategy monitor control is investigated for the case of task execution in a memory hierarchy of varying speeds
CACM	arguments for a moratorium on the construction of a community information utility in this article the author urges a prudent and decentralized approach to the question of the design and desirability of computerized community information utilities before accepting the inevitability and desirability of this or any technology we should 1 be sure of the feasibility internally and externally of what is proposed 2 project and perhaps wait for changes in complementary techniques 3 evaluate current and projected supplementary techniques 4 establish the existence of demand for what is proposed 5 take steps to involve a representative group of ultimate users in systems design and 6 carefully think through possible side effects on man and his world view current proposals for community information utilities are examined in this framework and the conclusion is drawn that society is not yet in a position to justify either the construction of an information utility in a prototype community or the acceptance of a policy in favor of its widespread implementation
CACM	computer programming as an art
CACM	multiple exists from a loop using neither go to nor labels
CACM	the best match problem in document retrieval
CACM	a simple technique for representing strings in fortran iv
CACM	an on site data management system application in field archaeology
CACM	self stabilizing systems in spite of distributed control
CACM	register allocation via usage counts this paper introduces the notion of usage counts shows how usage counts can be developed by algorithms that eliminate redundant computations and describes how usage counts can provide the basis for register allocation the paper compares register allocation based on usage counts to other commonly used register allocation techniques and presents evidence which shows that the usage count technique is significantly better than these other techniques
CACM	a method for composing simple traditional music by computer a method is described for composing musical rounds by computer this method uses some music theory plus additional heuristics fundamental to the method is a set of productions together with sets of applicability rules and weight rules which operate on the productions deciding when and to what extent they are available for use several rounds generated by the computer implementation of the method are presented generally the resultant music sounds mediocre to the professional although usually pleasing to the layman it appears that full blown music theory is not needed for rounds  all the hardware required for structural levels is not necessary for these pieces the author has tried to address both musicians and computer scientists
CACM	a locally organized parser for spoken input this paper describes lpars a locally organized parsing system designed for use in a continuous speech recognizer lpars processes a string of phonemes which contains ambiguity and error the system is locally organized in the sense that it builds local parse structures from reliable word candidates recognized anywhere in an input utterance these local structures are used as islands of reliability to guide the search for more highly garbled words which might complete the utterance
CACM	improving locality by critical working sets a new approach to program locality improvement via restructuring is described the method is particularly suited to those systems where primary memory is managed according to a working set strategy it is based on the concept of critical working set a working set which does not contain the next memory reference the data the method operates upon are extracted from a trace of the program to be restructured it is shown that except in some special cases the method is not optimum however the experimental results obtained by using the method to restructure an interactive text editor and the file system module of an operating system have shown its substantial superiority over the other methods proposed in the literature
CACM	guidelines for humanizing computerized information systems a report from stanley house
CACM	enumerating full time programmers data from the 1970 census and the department of labors area wage surveys are used to derive estimates of the number of full time programmers employed during the years 1969 through 1973 the 1973 figure of 180 000 is considerably less than suggested in earlier reports it is recommended that educational administrators consider whether the many courses aimed at training programmers are justified on a vocational basis
CACM	efficient implementation of a variable projection algorithm for nonlinear least squares problems errata
CACM	adapting optimal code generation for arithmetic expressions to the instruction sets available on present day computers errata
CACM	on the construction of a representative synthetic workload errata
CACM	rosenbrock function minimization algorithm r450
CACM	a computer routine for quadratic and linear programming problems algorithm r431
CACM	hypergeometric algorithm c191
CACM	numerical inversion of laplace transform algorithm a486
CACM	on generation of test problems for linear programming codes users of linear programming computer codes have realized the necessity of evaluating the capacity effectiveness and accuracy of the solutions provided by such codes large scale linear programming codes at most installations are assumed to be generating correct solutions without ever having been bench marked by test problems with known solutions the reason for this failure to adequately test the codes is that rarely are there large problems with known solutions readily available this paper presents a theoretical justification and an illustrative implementation of a method for generating linear programming test problems with known solutions the method permits the generation of test problems that are of arbitrary size and have a wide range of numerical characteristics
CACM	a back end computer for data base management it is proposed that the data base management function be placed on a dedicated back end computer which accepts commands in a relatively high level language such as the codasyl data base task group april 1971 report from a host computer accesses the data base on secondary storage and returns results the advantages of such a configuration are discussed an experimental implementation called the experimental data management system xdms is described and certain conclusions about the back end approach are drawn from this implementation
CACM	structured data structures programming systems which permit arbitrary linked list structures enable the user to create complicated structures without sufficient protection deletions can result in unreachable data elements and there is no guarantee that additions will be performed properly to remedy this situation this paper proposes a gauge which provides for the creation of a restricted class of data structures but ensures the correctness of the program this is accomplished by an explicit structure declaration facility a restriction on the permissible operations and execution time checks
CACM	a note on the calculation working set size finite length reference string of arbitrary structure are considered and an exact expression for average working set size in terms of corrected interreference interval statistics is derived an example is discussed upper and lower bounds are obtained and the average working set size function is shown to be efficiently obtained for a set of page sizes in a single pass of the reference string this work follows the developments of a paper by denning and schwartz who consider infinite length reference strings which satisfy certain statistical properties and who derive an expression relating the asymptotic average working set size to the asymptotic missing page rate function under working set replacement
CACM	a weighted buddy method for dynamic storage allocation an extension of the buddy method called the weighted buddy method for dynamic storage allocation is presented the weighted buddy method allows block sizes of 2 k and 3 2 k whereas the original buddy method allowed only block sizes of 2 k this extension is achieved at an additional cost of only two bits per block simulation results are presented which compare this method with the buddy method these results indicate that for a uniform request distribution the buddy system has less total memory fragmentation than the weighted buddy algorithm however the total fragmentation is smaller for the weighted buddy method when the requests are for exponentially distributed block sizes
CACM	monitors an operating system structuring concept this paper develops brinch hansens concept of a monitor as a method of structuring an operating system it introduces a form of synchronization describes a possible method of implementation in terms of semaphores and gives a suitable proof rule illustrative examples include a single resource scheduler a bounded buffer an alarm clock a buffer pool a disk head optimizer and a version of the problem of readers and writers
CACM	extending the information theory approach to converting limited entry decision tables to computer programs this paper modifies an earlier algorithm for converting decision tables into flowcharts which minimize subsequent execution time when compiled into a computer program the algorithms considered in this paper perform limited search and accordingly do not necessarily result in globally optimal solutions however the greater search effort needed to obtain a globally optimal solution for complex decision tables is usually not justified by sufficient savings in execution time there is an analogy between the problem of converting decision tables into efficient flowcharts and the well understood problem in information theory of noiseless coding the results of the noiseless coding literature are used to explore the limitations of algorithms used to solve the decision table problem the analogy between the two problems is also used to develop improvements to the information algorithm in extending the depth of search under certain conditions and in proposing additional conditions to be added to the decision table finally the information algorithm is compared with an algorithm proposed in a recent paper by verhelst
CACM	first order approximation to the optimum checkpoint interval
CACM	computation of g splines via a factorization method e2 algorithm a485
CACM	evaluation of the modified bessel functions k0 z and k1 z for complex arguments s17 algorithm a484
CACM	masked three dimensional plot program with rotations j6 algorithm a483
CACM	the equivalence of reducing transition languages and deterministic languages the class of reducing transition languages introduced by eickel paul bauer and samelson was shown by morris to be a proper superclass of the simple precedence languages in this paper this result is extended showing that in fact the first class is equivalent to the class of deterministic context free languages
CACM	an interactive graphic display for region partitioning by linear programming using linear programming an interactive graphic display system has been implemented to solve the region design problem of partitioning a region into n nonoverlapping subregions in such a way that their areas are in specified proportions and that the total cost of servicing them is a minimum in a conversational manner a user can easily obtain different partitionings by specifying and modifying the boundary the service centers locations the area proportions and the cost functions examples are included
CACM	a precise numerical analysis program a description is given of a program for computing the solution to a small number of standard numerical analysis problems to any specified accuracy up to a limit of 2000 correct decimal places each computed number is bounded in an interval with a multiple precision midpoint arithmetic operations involving these numbers are executed according to interval arithmetic concepts with non significant digits automatically discarded details are supplied of problem specification and problem computation
CACM	a new integration algorithm for ordinary differential equations based on continued fraction approximations a new integration algorithm is found and an implementation is compared with other programmed algorithms the new algorithm is a step by step procedure for solving the initial value problem in ordinary differential equations it is designed to approximate poles of small integer order in the solutions of the differential equations by continued fractions obtained by manipulating the sums of truncated taylor series expansions the new method is compared with gragg bulirsh stoer and the taylor series method the taylor series method and the new method are shown to be superior in speed and accuracy while the new method is shown to be most superior when the solution is required near a singularity the new method can finally be seen to pass automatically through singularities where all the other methods which are discussed will have failed
CACM	a problem list of issues concerning computers and public policy
CACM	recurrence relations for the fresnel integral and similar integrals
CACM	interpolation with rounded ramp functions a new interpolation function is introduced it has infinitely many continuous derivatives and is a composition of ramp functions with smoothed bends called rounded ramp functions how the interpolation function can be extended to more than one variable is shown an efficient fortran program is given by which the interpolation function can be obtained for a given point set
CACM	gauss harmonic interpolation formulas let r be an open bounded simply connected region in the x y  plane and let x y be a point in r assuming r is starlike with respect to x y we discuss a method for computing gauss harmonic interpolation formulas for r and the point x y such formulas approximate a harmonic function at x y in terms of a linear combination of its values at certain selected points on the boundary of r such formulas are useful for approximating the solution of the dirichlet problem for r
CACM	the complex method for constrained optimization algorithm r454
CACM	rosenbrock function minimization algorithm r450
CACM	transitivity sets g7 algorithm a482
CACM	arrow to precedence network transformation h algorithm a481
CACM	procedures for computing smoothing and interpolating natural splines e1 algorithm a480
CACM	on the conversion of programs to decision tables method and objectives the problems of converting programs to decision tables are investigated objectives of these conversions are mainly program debugging and optimization in practice extensions to the theory of computation and computability are suggested
CACM	a note on subexpression ordering in the evaluation of arithmetic expressions
CACM	a new solution of dijkstras concurrent programming problem a simple solution to the mutual exclusion problem is presented which allows the system to continue to operate despite the failure of any individual component
CACM	graph coloring conditions for the existence of solutions to the timetable problem a necessary and sufficient condition is presented for the existence of a solution to the gotlieb class teacher timetable problem several relationships are established between the class teacher timetable problem and graphs with preconditions these preconditions place additional restrictions on the coloration of a graph the preconditions correspond to the unavailability constraints and preassigned meetings in the class teacher timetable problem using some recent results that convert graphs with preconditions to graphs without them it is shown that the existence of a coloration of a graph is the required necessary and sufficient condition
CACM	execution time requirements for encipherment programs although encipherment has often been discussed as a means to protect computer data its costs are not well established five experiments were conducted to measure the cpu time on a cdc 6400 required by additive ciphers programmed both in assembly language and in fortran a null transformation to measure the time to move data without encipherment encipherment with one word key encipherment with a 125 word key double key encipherment and encipherment using a pseudo random key the results were analyzed for consistency over 100 runs and the effects of constant and intermittent errors were considered timing rates for assembly language encipherment ranged from 498 800 characters per second for a pseudo random key cipher to 2 092 000 characters per second for a constant one word key cipher the latter is almost equivalent to the rate required simply to move data without encipherment fortran tests required over four times as much cpu time this paper introduces the idea on enciphering time coefficient the ratio of enciphering time to the time taken to fetch and store data without encipherment
CACM	a high security log in procedure the protection of time sharing systems from unauthorized users is often achieved by the use of passwords by using one way ciphers to code the passwords the risks involved with storing the passwords in the computer can be avoided we discuss the selection of a suitable one way cipher and suggest that for this purpose polynomials over a prime modulus are superior to one way ciphers derived from sannon codes
CACM	a user authentication scheme not requiring secrecy in the computer in many computer operating systems a user authenticates himself by entering a secret password known solely to himself and the system the system compares this password with one recorded in a password table which is available to only the authentication program the integrity of the system depends on keeping the table secret in this paper a password scheme is presented which does not require secrecy in the computer all aspects of the system including all relevant code and data bases may be known by anyone attempting to intrude the scheme is based on using a function h which the would be intruder is unable to invert this function is applied to the users password and the result compared to a table entry a match being interpreted as authentication of the user the intruder may know all about h and have access to the table but he can penetrate the system only if he can invert h to determine an input that produces a given output this paper discusses issues surrounding selection of a suitable h two different plausible arguments are given that penetration would be exceedingly difficult and it is then argued that more rigorous results are unlikely finally some human engineering problems relating to the scheme are discussed
CACM	a new technique for compression and storage of data the widespread tendency toward storage of large programs and blocks off text has produced a need for efficient methods of compressing and storing data this paper describes techniques that can in most cases decrease storage size by a factor of from two to four the techniques involve special handling of leading and trailing blanks and the encoding of other symbols in groups of fixed size as unique fixed point numbers the efficiency of the system is considered and pertinent statistics are given and compared with statistics for other information coding techniques
CACM	formal requirements for virtualizable third generation architectures virtual machine systems have been implemented on a limited number of third generation computer systems e g cp 67 on the ibm 360 67 from previous empirical studies it is known that certain third generation computer systems e g the dec pdp 10 cannot support a virtual machine system in this paper model of a third generation like computer system is developed formal techniques are used to derive precise sufficient conditions to test whether such an architecture can support virtual machines
CACM	capability based addressing various addressing schemes making use of segment tables are examined the inadequacies of these schemes when dealing with shared addresses are explained these inadequacies are traced to the lack of an efficient absolute address for objects in these systems the direct use of a capability as an address is shown to overcome these difficulties because it provides the needed absolute address implementation of capability based addressing is discussed it is predicted that the use of tags to identify capabilities will dominate a hardware address translation scheme which never requires the modification of the representation of capabilities is suggested the scheme uses a main memory hash table for obtaining a segments location in main memory given its unique code the hash table is avoided for recently accessed segments by means of a set of associative registers a computer using capability based addressing may be substantially superior to present systems on the basis of protection simplicity of programming conventions and efficient implementation
CACM	protection and the control of information sharing in multics the design of mechanisms to control the sharing of information in the multics system is described five design principles help provide insight into the tradeoffs among different possible designs the key mechanisms described include access control lists hierarchical control of access specifications identification and authentication of users and primary memory protection the paper ends with a discussion of several known weaknesses in the current protection mechanism design
CACM	scheduling independent tasks to reduce mean finishing time sequencing to minimize mean finishing time or mean time in system is not only desirable to the user but it also tends to minimize at each point in time the storage required to hold incomplete tasks in this paper a deterministic model of independent tasks is introduced and new results are derived which extend and generalize the algorithms known for minimizing mean finishing time in addition to presenting and analyzing new algorithms it is shown that the most general mean finishing time problem for independent tasks is polynomial complete and hence unlikely to admit of a non enumerative solution
CACM	minimal total processing time drum and disk scheduling disciplines this article investigates the application of minimal total processing time mtpt scheduling disciplines to rotating storage units when random arrival of requests is allowed fixed head drum and moving head drum and moving head disk storage units are considered and emphasis is placed on the relative merits of the mtpt scheduling discipline with respect to the shortest latency time first sltf scheduling discipline the results of the simulation studies presented show that neither scheduling discipline is unconditionally superior to the other for most fixed head drum applications the sltf discipline is preferable to mtpt but for intra cylinder disk scheduling the mtpt discipline offers a distinct advantage over the sltf discipline the computational requirements of an algorithm that implements the mtpt scheduling discipline are shown to be comparable to sltf algorithms in both cases the sorting procedure is the most time consuming phase of the algorithm
CACM	the unix time sharing system unix is a general purpose multi user interactive operating system for the digital equipment corporation pdp 11 40 and 11 45 computers it offers a number of features seldom found even in larger operating systems including 1 a hierarchical file system incorporating demountable volumes 2 compatible file device and inter process i o 3 the ability to initiate asynchronous processes 4 system command language selectable on a per user basis and 5 over 100 subsystems including a dozen languages this paper discusses the nature and implementation of the file system and of the user command interface
CACM	on computing sets of shortest paths in a graph two algorithms are presented that construct the k shortest paths between every pair of vertices in a directed graph these algorithms generalize the floyd algorithm and the dantzig algorithm for finding the shortest path between every pair of vertices in a directed graph
CACM	an information theoretic approach to text searching in direct access systems using direct access computer files of bibliographic information an attempt is made to overcome one of the problems often associated with information retrieval namely the maintenance and use of large dictionaries the greater part of which is used only infrequently a novel method is presented which maps the hyperbolic frequency distribution this is more suited to implementation on storage devices this method treats text as a string of characters rather than words bounded by spaces and chooses subsets of strings such that their frequencies of occurrence are more even than those of word types the members of this subset are then used as index keys for retrieval the rectangular distribution of key frequencies results in a much simplified file organization and promises considerable cost advantages
CACM	hydra the kernel of a multiprocessor operating system this paper describes the design philosophy of hydra the kernel of an operating system for c mmp the carnegie mellon multi mini processor this philosophy is realized through the introduction of a generalized notion of resource both physical and virtual called an object mechanisms are presented for dealing with objects including the creation of new types specification of new operations applicable to a given type sharing and protection of any reference to a given object against improper application of any of the operations defined with respect to that type of object the mechanisms provide a coherent basis for extension of the system in two directions the introduction of new facilities and the creation of highly secure systems
CACM	compact representation of contour plots for phone line transmission methods for the compact representation of contour plots are described and tested these are intended to reduce the cost of transmitting contour plots over phone lines we feel some of these methods could be used to transmit contour plots over voice grade phone lines
CACM	an evaluation of statistical software in the social sciences several hundred college and university computer installations now offer various types of statistical packages for general use among those most widely available are osiris spss bmd data text and tsar in order to provide users with a basis for selection and use tests were made for each of these systems and the results are summarized as to cost and performance
CACM	exact probabilities for r x c contingency tables algorithm r434
CACM	generation of random correlated normal variables algorithm r425
CACM	hidden line plotting program algorithm r420
CACM	hidden line plotting program algorithm r420
CACM	calculation of fourier integrals algorithm r418
CACM	modified havie integration algorithm r400
CACM	a minimal spanning tree clustering method z algorithm a479
CACM	solution of an overdetermined system of equations in the l1 norm f4 algorithm a478
CACM	the minimization of spatially multiplexed character sets the paper describes a technique for compacting character sets in a digital computer while retaining fast access to individual bits it considers the problem of minimizing the storage needed to contain such tables reduction techniques are developed and the problem is shown to reduce to a covering problem
CACM	a theorem proving language for experimentation because of the large number of strategies and inference rules presently under consideration in automated theorem proving there is a need for developing a language especially oriented toward automated theorem proving this paper discusses some of the features and instructions of this language the use of this language permits easy extension of automated theorem proving programs to include new strategies and or new inference rules such extend ability will permit general experimentation with the various alternative systems
CACM	two languages for estimating program efficiency two languages enabling their users to estimate the efficiency of computer programs are presented the program whose efficiency one wishes to estimate is written in the first language a go to less programming language which includes most of the features of algol 60 the second language consists of interactive commands enabling its users to provide additional information about the program written in the first language and to output results estimating its efficiency processors for the two languages are also described the first processor is a syntax directed translator which compiles a program into a symbolic formula representing the execution time for that program the sound processor is a set of procedures for that program the second processor is a set of procedures for algebraic manipulation which can be called by the user to operate on the formula produced by the first processor examples of the usage of the two languages are included the limitations of the present system its relation to knuths work on the analysis of algorithms and some of the directions for further research are also discussed
CACM	a model for masking rotational latency by dynamic disk allocation this paper presents the background and algorithms for masking the rotational latency of a disk or drum it discusses the anticipatory input and output of blocks of data to buffer and primary memories for a mono programmed computer system a basic permutation algorithm and several variations are given because of the anticipatory nature of the i o scheduling these algorithms are restricted to classes of programs with predictable behavior while the methods are not restricted to numerical computations matrix and partial differential equation methods are typical examples of their use it is shown that latency may be masked using a small amount of buffer memory the methods discussed are independent of the overall size of the data base being considered
CACM	more on algorithms that reveal properties of floating point arithmetic units
CACM	a design for a number theory package with an optimized trial division routine a number theory package is described which uses doubly linked list structures for storing multiprecise integers the package has been coded in ibms basic assembly language and makes heavy use of the macro language and conditional assembly an optimally coded trial division routine is also described which can be used to determine the unique factorization of large integers
CACM	on the distributions of significant digits and roundoff errors generalized logarithmic law is derived for the distribution of the first t significant digits of a random digital integer this result is then used to determine the distribution of the roundoff errors in floating point operations which is a mixture of uniform and reciprocal distributions
CACM	order n correction for regular languages a method is presented for calculating a string b belonging to a given regular language l which is nearest in number of edit operations to a given input string a b is viewed as a reasonable correction for the possibly erroneous string a where a was originally intended to be a string of l the calculation of b by the method presented requires time proportional to a the number of characters in a the method should find applications in information retrieval artificial intelligence and spelling correction systems
CACM	the treatment of data types in el1 in constructing a general purpose programming language a key issue is providing a sufficient set of data types and associated operations in a manner that permits both natural problem oriented notation and efficient implementation the el1 language contains a number of features specifically designed to simultaneously satisfy both requirements the resulting treatment of data types includes provision for programmer defined data types data types and generic routines programmer control over type conversion and very flexible data type behavior in a context that allows efficient compiled code and compact data representation
CACM	reduction of compilation costs through language contraction programming languages tailored to particular groups of users can often be constructed by removing unwanted features from a general purpose language this paper describes the use of simulation techniques to predict the savings in compilation cost achievable by such an approach the results suggest a function which describes the effect of changes in the power of a language on the compilation cost of an algorithm expressed in that language when features not actually used by the algorithm are removed from the language the cost of compiling the algorithm decreases moderately but when features that are needed are removed the compilation cost increases sharply
CACM	solution of the transcendental equation w exp x x algorithm r443
CACM	generator of set partitions to exactly r subsets g7 algorithm a477
CACM	six subprograms for curve fitting using splines under tension e2 algorithm a476
CACM	scalar  and planar  valued curve fitting using splines under tension the spline under tension was introduced by schweikert in an attempt to imitate cubic splines but avoid the spurious critical points they induce the defining equations are presented here together with an efficient method for determining the necessary parameters and computing the resultant spline the standard scalar valued curve fitting problem is discussed as well as the fitting of open and closed curves in the plane the use of these curves and the importance of the tension in the fitting of contour lines are mentioned as application
CACM	an improved program synthesizing algorithm and its correctness an improved program synthesizing algorithm based on the algorithm proposed by waldinger and lee in 1969 is given in the old algorithm the program synthesizing problem is translated into a theorem proving problem and a program is obtained by analyzing a proof for the improved algorithm the analysis is not necessary and a program is obtained as soon as the proof is completed this is achieved by using a modified variable tracing mechanism invented by green in 1969 the correctness of the improved algorithm is also proved i e the program thus obtained always satisfies the specification
CACM	an alternative approach to mutual recursion in algol 60 using restricted compilers
CACM	some remarks on lookup of structured variables
CACM	addendum to m l patrick paper
CACM	ideal teaching machines a solution to the pedagogic language problem
CACM	graduate education the ph d glut response and rebuttal
CACM	a study of computer use in a graduate school of business
CACM	parallelism in tape sorting two methods for employing parallelism in tape sorting are presented method a is the natural way to use parallelism method b is new both approximately achieve the goal of reducing the processing time by a divisor which is the number of processors
CACM	copying list structures using bounded workspace two new algorithms are presented for list structure copying using bounded workspace the first of primarily theoretical interest shows that without cell tag bits the task can be performed in time n 2 the second algorithm assuming one tag bit in each cell delivers attractive practical speed any noncyclic structure is copied in linear speed while cyclic structures are copied in average time less than nlogn no foreknowledge of cycle absence is necessary to achieve linear speed a variation of the second algorithm solves an open problem concerning list structure marking that result demonstrates that marking can be done in average time nlogn without the aid of supplemental tag bits or stacks
CACM	on lions counter example for gotliebs method for the construction of school timetables the timetable problem is an essentially discrete problem although the discrete problem may have no feasible solution there may exist a solution to the equivalent continuous problem an example is given for which the nondiscrete solution can be interpreted as a set of timetables differing from week to week which together satisfy the long term requirements of the timetable problem
CACM	execution characteristics of programs in a page on demand system data are presented which show the execution characteristics of two types of commonly used programs in a large scale time shared computer system a software monitoring facility built into the supervisor was used for data collection during normal system operation these data were analyzed and results of this analysis are presented for a fortran compiler and an interactive line file editor probability distribution functions and other data are given for such things as cpu intervals i o intervals and the number of such intervals during execution empirical distributions are compared with simple theoretical distributions exponential hyperexponential and geometric other data show paging characteristics of tasks as a function of the number of pages those tasks have in core
CACM	computation of page fault probability from program transition diagram an algorithm is given for calculating page fault probability in a virtual memory system operating under demand paging with various memory sizes and replacement rules a first order markov model of program behavior is assumed and a representation of the system based on memory states control states and memory substates is presented the algorithm is general in the sense that the page fault probabilities can be calculated for nonpredictive replacement rules applied to any program represented by a one step markov chain a detailed example is given to illustrate the algorithm for random and least recently used lru replacement rules
CACM	a simple linear model of demand paging performance predicting the performance of a proposed automatically managed multilevel memory system requires a model of the patterns by which programs refer to the information stored in the memory some recent experimental measurements on the multics virtual memory suggest that for rough approximations a remarkably simple program reference model will suffice the simple model combines the effect of the information reference pattern with the effect of the automatic management algorithm to produce a single composite statement the mean number of memory references between paging exceptions increases linearly with the size of the paging memory the resulting model is easy to manipulate and is applicable to such diverse problems as choosing an optimum size for a paging memory arranging for reproducible memory usage charges and estimating the amount of core memory sharing
CACM	efficient implementation of a variable projection algorithm for nonlinear least squares problems nonlinear least squares frequently arise for which the variables to be solved for can be separated into a linear and a nonlinear part a variable projection algorithm has been developed recently which is designed to take advantage of the structure of a problem whose variables separate in this way this paper gives a slightly more efficient and slightly more general version of this algorithm than has appeared earlier
CACM	a note on a combinatorial problem of burnett and coffman
CACM	emotional content considered dangerous
CACM	quadratic search for hash tables of size p n
CACM	scan conversion algorithms for a cell organized raster display raster scan computer graphics with real time character generators have previously been limited to alphanumeric characters a display has been described which extends the capabilities of this organization to include general graphics two fundamentally different scan conversion algorithms which have been developed to support this display are presented one is most suitable to non interactive applications and the other to interactive applications the algorithms were implemented in fortran on the cdc 6400 computer results obtained from the implementations show that the noninteractive algorithms can significantly reduce display file storage requirements at little cost in execution time over that of a conventional raster display the interactive algorithm can improve response time and reduce storage requirements
CACM	a computer routine for quadratic and linear programming problems algorithm r431
CACM	zeros of a complex polynomial algorithm r419
CACM	incomplete beta ratio algorithm r179
CACM	visible surface plotting program j6 algorithm a475
CACM	some performance tests of quicksort and descendants detailed performance evaluations are presented for six acm algorithms quicksort no 64 shellsort no 201 stringsort no 207 treesort3 no 245 quickersort no 271 and qsort no 402 algorithms 271 and 402 are refinements of algorithm 64 and all three are discussed in some detail the evidence given here demonstrates that qsort no 402 requires many more comparisons than its author claims of all these algorithms quickersort requires the fewest comparisons to sort random arrays
CACM	optimal space allocation on disk storage devices when the amount of space required for file storage exceeds the amount which can be kept on line decisions must be made as to which files are to be permanently resident and which mountable these decisions will affect the number of mount requests issued to the operators this is often a bottleneck in a computing facility and reducing the number of mounts thus decreases turnaround time an optimization model for the assignment of files to disk packs and packs to either resident or nonresident status is presented heuristics are suggested for those cases in which it is inefficient to compute the actual optimum
CACM	dynamic memory repacking a probabilistic model of a multiprogramming system is exercised in order to determine the conditions under which the dynamic repacking of main memory is beneficial an expression is derived for the maximum interference that a repacking process may introduce before the original performance of the system is degraded alternative approaches to repacking are discussed and the operating conditions that lead to improved system throughput through repacking are delineated
CACM	on the construction of a representative synthetic workload a general method of constructing a drive workload representative of a real workload is described the real workload is characterized by its demands on the various system resources these characteristics of the real workload are obtained from the system accounting data the characteristics of the drive workload are determined by matching the joint probability density of the real workload with that of the drive workload the drive workload is realized by using a synthetic program in which the characteristics can be varied by varying the appropriate parameters calibration experiments are conducted to determine expressions relating the synthetic program parameters with the workload characteristics the general method is applied to the case of two variables cpu seconds and number of i o activities and synthetic workload with 88 jobs is constructed to represent a months workload consisting of about 6000 jobs
CACM	the synthesis of loop predicates current methods for mechanical program verification require a complete predicate specification on each loop because this is tedious and error prone producing a program with complete correct predicates is reasonably difficult and would be facilitated by machine assistance this paper discusses techniques for mechanically synthesizing loop predicates two classes of techniques are considered 1 heuristic methods which derive loop predicates from boundary conditions and or partially specified inductive assertions 2 extraction methods which use input predicates and appropriate weak interpretations to obtain certain classes of loop predicates by an evaluation on the weak interpretation
CACM	production systems or can we do better than bnf since the development of bnf the definition of the syntax of programming languages has been almost universally associated with context free requirements yet numerous interesting and difficult issues in syntax stem from the context sensitive requirements notably the compatibility between the declaration of an identifier and its uses the correspondence between actual and formal parameters and issues arising from block structure this paper explores the use of a formal notation called production systems in providing a readable and complete formal definition of syntax as a practical illustration a small but significant subset of pl i is considered a more detailed presentation as well as the application to define abstract syntax and translations between languages is given in a previous paper by the author
CACM	the parallel execution of do loops methods are developed for the parallel execution of different iterations of a do loop both asynchronous multiprocessor computers and array computers are considered practical application to the design of compilers for such computers is discussed
CACM	an approximate method for generating asymmetric random variables tukeys lambda distribution is generalized to provide an algorithm for generating values of unimodal asymmetric random variables this algorithm has the same advantages as the symmetric random variable generator previously given by the authors except that the addition of another parameter complicates the problem of finding the parameter values to fit a distribution
CACM	a cell organized raster display for line drawings raster scan computer graphics displays with real time character generators have previously been limited to alphanumeric characters a display is described which extends the capabilities of this organization to include general graphics the feasibility of such a display is shown by deriving the minimum number of patterns required in the read only memory of the character generator to synthesize an arbitrary line the synthesis process does not compromise picture quality since the resulting dot patterns are identical with those of a conventional raster display furthermore the time constraints of a raster display are shown to be satisfied for a typical design for very complex line drawings
CACM	attribute based file organization in a paged memory environment the high cost of page accessing implies a need for more careful data organization in a paged memory than is typical of most inverted file and similar approaches to multi key retrieval this article analyses that cost and proposes a method called multiple key hashing which attempts to minimize it since this approach is not always preferable to inversion a combined method is described the exact specifications of this combination for a file with given data and traffic characteristics is formulated as a mathematical program the proposed heuristic solution to this program can often improve on a simple inversion technique by a factor of 2 or 3
CACM	a crt report generating system
CACM	a numbering systems for combinations
CACM	comments on the algorithms of verhelst for the conversion of limited entry decision tables to flowcharts
CACM	reentrant polygon clipping a new family of clipping algorithms is described these algorithms are able to clip polygons against irregular convex plane faced volumes in three dimensions removing the parts of the polygon which lie outside the volume in two dimensions the algorithms permit clipping against irregular convex windows polygons to be clipped are represented as an ordered sequence of vertices without repetition of first and last in marked contrast to representation as a collection of edges as was heretofore the common procedure output polygons have an identical format with new vertices introduced in sequence to describe any newly cut edge or edges the algorithms easily handle the particularly difficult problem of detecting that a new vertex may be required at a corner of the clipping window the algorithms described achieve considerable simplicity by clipping separately against each clipping plane or window boundary code capable of clipping the polygon against a single boundary is reentered to clip against subsequent boundaries each such reentrant stage of clipping need store only two vertex values and may begin its processing as soon as the first output vertex from the proceeding stage is ready because the same code is reentered for clipping against subsequent boundaries clipping against very complex window shapes is practical for perspective applications in three dimentions a six plane truncated pyramid is chosen as the clipping volume the two additional planes parallel to the projection screen serve to limit the range of depth preserved through the projection a perspective projection method which provides for arbitrary view angles and depth of field in spite of simple fixed clipping planes is described this method is ideal for subsequent hidden surface computations
CACM	bivariate interpolation and smooth surface fitting based on local procedures e2 algorithm a474
CACM	computation of legendre series coefficients c6 algorithm a473
CACM	tridiagonalization by permutations tridiagonalizing a matrix by similarity transformations is an important computational tool in numerical linear algebra consider the class of sparse matrices which can be tridiagonalized using only row and corresponding column permutations the advantages of using such a transformation include the absence of round off errors and improved computation time when compared with standard transformations a graph theoretic algorithm which examines an arbitrary n x n matrix and determines whether or not it can be permuted into tridiagonal form is given the algorithm requires no arithmetic while the number of comparisons the number of assignments and the number of increments are linear in n this compares very favorably with standard transformation methods if the matrix is permutable into tridiagonal form the algorithm gives the explicit tridiagonal form otherwise early rejection will occur
CACM	a method of bivariate interpolation and smooth surface fitting based on local procedures a method is designed for interpolating values given at points of a rectangular grid in a plane by a smooth bivariate function z z x y the interpolating function is a bicubic polynomial in each cell of the rectangular grid emphasis is an avoiding excessive undulation between given grid points the proposed method is an extension of the method of univariate interpolation developed earlier by the author and is likewise based on local procedures
CACM	a fast method for solving a class of tridiagonal linear systems the solution of linear systems having real symmetric diagonally dominant tridiagonal coefficient matrices with constant diagonals is considered it is proved that the diagonals of the lu decomposition converges when floating point precision it is also proved that the computed lu decomposition converges when floating point arithmetic is used and that the limits of the lu diagonals using floating point are roughly within machine precision of the limits using real arithmetic this fact is exploited to reduce the number of floating point operations required to solve a linear system from 8n 7 to 5n 2k 3 where k is much less than n the order of the matrix if the elements of the subdiagonals and superdiagonals are 1 then only 4n 2k 3 operations are needed the entire lu decomposition takes k words of storage and considerable savings in array subscripting are achieved upper and lower bounds on k are obtained in terms of the ratio of the coefficient matrix diagonal constants and parameters of the floating point number system various generalizations of these results are discussed
CACM	syntax directed least errors analysis for context free languages a practical approach a least errors recognizer is developed informally using the well known recognizer of earley along with elements of bellmans dynamic programming the analyzer takes a general class of context free grammars as drivers and any finite string as input recognition consists of a least errors count for a corrected version of the input relative to the driver grammar the algorithm design emphasizes practical aspects which help in programming it
CACM	automatic data structure choice in a language of very high level setl is a set theoretically oriented language of very high level whose repertoire of semantic objects includes finite sets ordered n tuples and sets of ordered n tuples usable as mappings this paper describes the structure of an optimizer for this language among other methods of interest the optimizer uses techniques which allow relations of inclusion and membership to be established the domains and ranges of tabulated mappings to be estimated from above and below and the single valuedness of tabulated mappings to be proved once facts of this kind have been established automatic choice of data structures becomes possible the methods employed are based upon and extend known techniques of data flow analysis
CACM	reduction a method of proving properties of parallel programs when proving that a parallel program has a given property it is often convenient to assume that a statement is indivisible i e that the statement cannot be interleaved with the rest of the program here sufficient conditions are obtained to show that the assumption that a statement is indivisible can be relaxed and still preserve properties such as halting thus correctness proofs of a parallel system can often be greatly simplified
CACM	a fast and usually linear algorithm for global flow analysis abstract only  complete paper jacm 23 1 january 1976 a new algorithm for global flow analysis on reducible graphs is presented the algorithm is shown to treat a very general class of function spaces for a graph of e edges the algorithm has a worst case time bound of o e log e function operations it is also shown that in programming terms the number of operations is proportional to e plus the number of exits from program loops consequently a restriction to one entry one exit control structures linearity the algorithm can be extended to yet larger classes of function spaces and graphs by relaxing the time bound examples are given of code improvement problems which can be solved using the algorithm
CACM	on the complexity of lr k testing the problem of determining whether an arbitrary context free grammar is a member of some easily parsed subclass of grammars such as the lr k grammars is considered the time complexity of this problem is analyzed both when k is considered to be a fixed integer and when k is considered to be a parameter of the test in the first case it is shown that for every k there exists an o n k 2 algorithm for testing the lr k property where n is the size of the grammar in question on the other hand if both k and the subject grammar are problem parameters then the complexity of the problem depends very strongly on the representation chosen for k more specifically it is shown that this problem is np complete when k is expressed in unary when k is expressed in binary the problem is complete for nondeterministic exponential time these results carry over to many other parameterized classes of grammars such as the ll k strong ll k slr k lc k and strong lc k grammars
CACM	the intrinsically exponential complexity of the circularity problem for attribute grammars attribute grammars are an extension of context free grammars devised by knuth as a mechanism for including the semantics of a context free language with the syntax of the language the circularity problem for a grammar is to determine whether the semantics for all possible sentences programs in fact will be well defined it is proved that this problem is in general computationally intractable specifically it is shown that any deterministic algorithm which solves the problem must for infinitely many cases use an exponential amount of time an improved version of knuths circularity testing algorithm is also given which actually solves the problem within exponential time
CACM	exception handling issues and a proposed notation this paper defines exception conditions discusses the requirements exception handling language features must satisfy and proposes some new language features for dealing with exceptions in an orderly and reliable way the proposed language features serve to highlight exception handling issues by showing how deficiencies in current approaches can be remedied
CACM	programming languages natural languages and mathematics some social aspects of programming are illuminated through analogies with similar aspects of mathematics and natural languages the split between pure and applied mathematics is found similarly in programming the development of natural languages toward flexion less word order based language types speaks for programming language design based on general abstract constructs by analogy with incidents of the history of artificial auxiliary languages it is suggested that fortran and cobol will remain dominant for a long time to come the most promising avenues for further work of wide influence are seen to be high quality program literature i e programs of general utility and studies of questions related to program style
CACM	a note on the set basis problem related to the compaction of character sets this note discusses the reduction of the set basis problem to the clique cover problem
CACM	backtrack programming techniques the purpose of this paper is twofold first a brief exposition of the general backtrack technique and its history is given second it is shown how the use of macros can considerably shorten the computation time in many cases in particular this technique has allowed the solution of two previously open combinatorial problems the computation of new terms in a well known series and the substantial reduction in computation time for the solution to another combinatorial problem
CACM	practical syntactic error recovery this paper describes a recovery scheme for syntax errors which provides automatically generated high quality recovery with good diagnostic information at relatively low cost previous recovery techniques are summarized and empirical comparisons are made suggestions for further research on this topic conclude the paper
CACM	a genealogy of control structures the issue of program control structures has had a history of heated controversy to put this issue on a solid footing this paper reviews numerous theoretical results on control structures and explores their practical implications the classic result of bohm and jacopini on the theoretical completeness of if then else and while do is discussed several recent ideas on control structures are then explored these include a review of various other control structures results on time space limitations and theorems relating the relative power of control structures under notions of equivalence in conclusion the impact of theoretical results on the practicing programmer and the importance of one in one out control structures as operational abstractions are discussed it is argued further that there is insufficient evidence to warrant more than if then else while do and their variants
CACM	specifying queries as relational expressions the square data sublanguage this paper presents a data sublanguage called square intended for use in ad hoc interactive problem solving by non computer specialists square is based on the relational model of data and is shown to be relationally complete however it avoids the quantifiers and bound variables required by languages based on the relational calculus facilities for query insertion deletion and update on tabular data bases are described a syntax is given and suggestions are made for alternative syntaxes including a syntax based on english key words for users with limited mathematical background
CACM	a vector space model for automatic indexing in a document retrieval or other pattern matching environment where stored entities documents are compared with each other or with incoming patterns search requests it appears that the best indexing property space is one where each entity lies as far away from the others as possible in these circumstances the value of an indexing system may be expressible as a function of the density of the object space in particular retrieval performance may correlate inversely with space density an approach based on space density computations is used to choose an optimum indexing vocabulary for a collection of documents typical evaluation results are shown demonstrating the usefulness of the model
CACM	horners rule for the evaluation of general closed queueing networks the solution of separable closed queueing networks requires the evaluation of homogeneous multinomial expressions the number of terms in those expressions grows combinatorially with the size of the network such that a direct summation may become impractical an algorithm is given which does not show a combinatorial operation count the algorithm is based on a generalization of horners rule for polynomials it is also shown how mean queue size and throughput an be obtained at negligible extra cost once the normalization constant is evaluated
CACM	remark on stably updating mean and standard deviation of data corrigendum
CACM	merging with parallel processors consider two linearly ordered sets a b a m b n m n and p p m parallel processors working synchronously the paper presents an algorithm for merging a and b with the p parallel processors which requires at most 2 log2 2m 1 3m p m p log2 n m steps if n 2 b m b an integer the algorithm requires at most 2 log2 m 1 m p 2 b steps in the case where m and n are of the same order of magnitude i e n km with k being a constant the algorithm requires 2 log2 m 1 m p 3 k steps these performances compare very favorably with the previous best parallel merging algorithm batchers algorithm which requires n p m n 2p log2 m steps in the general case and km p k 1 2 m p log2 m in the special case where n km
CACM	implementation of a structured english query language the relational model of data the xrm relational memory system and the sequel language have been covered in previous papers and are reviewed sequel is a relational data sublanguages intended for the ad hoc interactive problem solving by non computer specialists a version of sequel that has been implemented in a prototype interpreter is described the interpreter is designed to minimize the data accessing operations required to respond to an arbitrary query the optimization algorithms designed for this purpose are described
CACM	optimizing the performance of a relational algebra database interface an approach for implementing a smart interface to support a relational view of data is proposed the basic idea is to employ automatic programming techniques so that the interface analyzes and efficiently refines the high level query specification supplied by the user a relational algebra interface called squiral which was designed using this approach is described in detail squiral seeks to minimize query response time and space utilization by 1 performing global query optimization 2 exploiting disjoint and pipelined concurrency 3 coordinating sort orders in temporary relations 4 employing directory analysis and 5 maintaining locality in page references algorithms for implementing the operators of e f codds relational algebra are presented and a methodology for composing them to optimize the performance of a particular user query is described
CACM	convert a high level translation definition language for data conversion this paper describes a high level and nonprocedural translation definition language convert which provides very powerful and highly flexible data restructuring capabilities its design is based on the simple underlying concept of a form which enables the users to visualize the translation processes and thus makes data translation a much simpler task convert has been chosen for conveying the purpose of the language and should not be confused with any other language or program bearing the same name
CACM	a preliminary system for the design of dbtg data structures the functional approach to database design is introduced in this approach the goal of design is to derive a data structure which is capable of supporting a set of anticipated queries rather than a structure which models the business in some other way an operational computer program is described which utilizers the functional approach to design data structures conforming to the data base task group specifications the automatic programming technology utilized by this program although typically used to generate procedure is here used to generate declaratives
CACM	mechanical program analysis one means of analyzing program performance is by deriving closed form expressions for their execution behavior this paper discusses the mechanization of such analysis and describes a system metric which is able to analyze simple lisp programs and produce for example closed form expressions for their running time expressed in terms of size of input this paper presents the reasons for mechanizing program analysis describes the operation of metric explains its implementation and discusses its limitations
CACM	optimal balancing of i o requests to disks determining a policy for efficient allocation and utilization of a set of disk drives with differing operational characteristics is examined using analytical techniques using standard queueing theory each disk drive is characterized by a queueing model with service time of a disk drive represented by the probability density function of the sum of two uniform distributions total response time of the set of disk models is then minimized under varying load conditions the results indicate that faster devices should have higher utilization factors and that the number of different device types utilized tends to decrease with decreasing load specific examples using 2314 and 3330 combinations are examined
CACM	the digital simulation of river plankton population dynamics this paper deals with the development of a mathematical model for and the digital simulation in fortran iv of phytoplankton and zooplankton population densities in a river using previously developed rate expressions in order to study the relationships between the ecological mechanisms involved the simulation parameters were varied illustrating the response of the ecosystem to different conditions including those corresponding to certain types of chemical and thermal pollution as an investigation of the accuracy of the simulation methods a simulation of the actual population dynamics of asterionella in the columbia river was made based on approximations of conditions in that river although not totally accurate the simulation was found to predict the general annual pattern of plankton growth fairly well and specifically revealed the importance of the annual velocity cycle in determining such patterns in addition the study demonstrates the usefulness of digital simulations in the examinations of certain aquatic ecosystems as well as in environmental planning involving such examinations
CACM	multidimensional binary search trees used for associative searching this paper develops the multidimensional binary search tree or k d tree where k is the dimensionality of the search space as a data structure for storage of information to be retrieved by associative searches the k d tree is defined and examples are given it is shown to be quite in its storage requirements a significant advantage of this structure is that a single data structure can handle many types of queries very efficiently various utility algorithms are developed their proven average running times in an n record file are insertion o log n deletion of the root o n k 1 k deletion of a random node o log n and optimization guarantees logarithmic performance of searches o n log n search algorithms are given for partial match queries with t keys specified proven maximum running time of o n k t k and for nearest neighbor queries empirically observed average running time of o log n these performances far surpass the best currently known algorithms for these tasks an algorithm is presented to handle any general intersection query the main focus of this paper theoretical it is felt however that k d trees could be quite useful in many applications and examples of potential uses are given
CACM	multiprocessing compactifying garbage collection algorithms for a multiprocessing compactifying garbage collector are presented and discussed the simple case of two processors one performing lisp like list operations and the other performing garbage collection continuously is thoroughly examined the necessary capabilities of each processor are defined as well as interprocessor communication and interlocks complete procedures for garbage collection and for standard list processing primitives are presented and thoroughly explained particular attention is given to the problems of marking and relocating list cells while another processor may be operating on them the primary aim throughout is to allow the list processor to run unimpeded while the other processor reclaims list storage the more complex cases involving several list processors and one or more garbage collection processors are also briefly discussed
CACM	the lemniscate constants corrigendum
CACM	a comparison of simulation event list algorithms corrigendum
CACM	combining decision rules in a decision table the techniques for minimizing logic circuits are applied to the simplification of decision tables by the combining of decision rules this method is logically equivalent to the quien mccluskey method for finding prime implicants if some of the decision rules implied in the else rule occur with low frequency then the else rule can be used to further simplify the decision table several objectives merit consideration in optimizing a decision table 1 reducing machine execution time 2 reducing preprocessing time 3 reducing required machine memory 4 reducing the number of decision rules this often improves the clarity of the decision table to a human reader it will be shown that objectives 3 and 4 can be furthered with the above methods objective 1 is also attained if overspecified decision rules are not combined objective 2 must be compared against the potential benefits of objectives 1 3 and 4 in deciding whether to use the above methods
CACM	multiple byte processing with full word instructions a method is described which allows parallel processing of packed data items using only ordinary full word computer instructions even though the processing requires operations whose execution is contingent upon the value of a datum it provides a useful technique for processing small data items such as alphanumeric characters
CACM	consecutive storage of relevant records with redundancy this paper studies the properties of a new class of file organizations crwr where records relevant to every query are stored in consecutive storage locations but the organizations contain redundancy some theorems which provide tools for reducing redundancy in crwr organizations have been also developed redundancies obtained by the application of these theorems are compared with that of query inverted file organizations some crwr organization with minimum redundancy have also been developed for queries which specify sets of keys
CACM	comments on a paper by t c chen and i t ho
CACM	interactive consulting via natural language interactive programming systems often contain help commands to give the programmer on line instruction regarding the use of the various systems commands it is argued that it would be relatively easy to make these help commands significantly more helpful by having them accept requests in natural language as a demonstration weizenbaums eliza program has been provided with a script that turns it into a natural language system consultant
CACM	remark on stably updating mean and standard deviation of data
CACM	guarded commands nondeterminacy and formal derivation of programs so called guarded commands are introduced as a building block for alternative and repetitive constructs that allow nondeterministic program components for which at least the activity evoked but possible even the final state is not necessarily uniquely determined by the initial state for the formal derivation of programs expressed in terms of these constructs a calculus will be shown
CACM	deterministic parsing of ambiguous grammars methods of describing the syntax of programming languages in ways that are more flexible and natural than conventional bnf descriptions are considered these methods involve the use of ambiguous context free grammars together with rules to resolve syntactic ambiguities it is shown how efficient lr and ll parsers can be constructed directly from certain classes of these specifications
CACM	on the external storage fragmentation produced by first fit and best fit allocation strategies published comparisons of the external fragmentation produced by first fit and best fit memory allocation have not been consistent through simulation a series of experiments were performed in order to obtain better data on the relative performance of first fit and best fit and a better understanding of the reasons underlying observed differences the time memory product efficiencies of first fit and best fit were generally within 1 to 3 percent of each other except for small populations the size of the request population had little effect on allocation efficiency for exponential and hyperexponential distributions of requests first fit outperformed best fit but for normal and uniform distributions and for exponential distributions distorted in various ways best fit outperformed first fit it is hypothesized that when first fit outperforms best fit it does so because first fit by preferentially allocating toward one end of memory encourages large blocks to grow at the other end sufficient contiguous space is thereby more likely to be available for relatively large requests results of simulation experiments supported this hypothesis and showed that the relative performance of first fit and best fit depends on the frequency of request when the coefficient of variation of the request distribution is greater than or approximately equal to unity first fit outperformed best fit
CACM	discrimination in the employment of women in the computer industry
CACM	a note on hash linking
CACM	determining the minimum area encasing rectangle for an arbitrary closed curve this paper describes a method for finding the rectangle of minimum area in which a given arbitrary plane curve can be contained the method is of interest in certain packing and optimum layout problems it consists of first determining the minimal perimeter convex polygon that encloses the given curve and then selecting the rectangle of minimum area capable of containing this polygon three theorems are introduced to show that one side of the minimum area rectangle must be colinear with an edge of the enclosed polygon and that the minimum area encasing rectangle for the convex polygon is also the minimum area rectangle for the curve
CACM	use of the concept of transparency in the design of hierarchically structured systems this paper deals with the design of hierarchically structured programming systems it develops a method for evaluating the cost of requiring programmers to work with an abstraction of a real machine a number of examples from hardware and software are given as illustrations of the method
CACM	the restriction language for computer grammars of natural language over the past few years a number of systems for the computer analysis of natural language sentences have been based on augmented context free grammars a context free grammar which defines a set of parse trees for a sentence plus a group of restrictions to which a tree must conform in order to be a valid sentence analysis as the coverage of the grammar is increased an efficient representation becomes essential for further development this paper presents a programming language designed specifically for the compact and perspicuous statement of restrictions of a natural language grammar it is based on ten years experience parsing text sentences with the comprehensive english grammar of the n y u linguistic string project and embodies in its syntax and routines the relations which were found to be useful and adequate for computerized natural language analysis the language is used in the current implementation of the linguistic string parser
CACM	a large semaphore based operating system the paper describes the internal structure of a large operating system as a set of cooperating sequential processes the processes synchronize by means of semaphores and extended semaphores queue semaphores the number of parallel processes is carefully justified and the various semaphore constructions are explained the system is proved to be free of deadly embrace deadlock the design principle is an alternative to dijkstras hierarchical structuring of operating systems the project management and the performance are discussed too the operating system is the first large one using the rc 4000 multiprogramming system
CACM	decomposability instabilities and saturation in multiprogramming systems a step by step approach to model the dynamic behavior and evaluate the performance of computing systems is proposed it is based on a technique of variable aggregation and the concept of nearly decomposable system both borrowed from econometrics this approach is taken in order to identify in multiprogramming paging systems i unstable regimes of operations and ii critical computing loads which bring the system into states of saturation this analysis leads to a more complete definition of the circumstances in which thrashing can set in
CACM	improved event scanning mechanisms for discrete event simulation simulation models of large complex real world applications have occasionally earned the reputation of eating up hours of computer time this problem may be attributed in part to difficulties such as slow stochastic convergence however an additional problem lies in the fact that a significant amount of bookkeeping time is required to keep future events in their proper sequence this paper presents a method for significantly reducing the time spent scanning future event lists in discrete event simulations there models are presented all of which improve in effectiveness as the events list scan problem becomes more burdensome
CACM	sorting x y
CACM	addition in an arbitrary base without radix conversion this paper presents a generalization of an old programming technique using it one may add and subtract numbers represented in any radix including a mixed radix and stored one digit per byte in bytes of sufficient size radix conversion is unnecessary no looping is required and numbers may even be stored in a display i o format applications to cobol mix and hexadecimal sums are discussed
CACM	a linear space algorithm for computing maximal common subsequences the problem of finding a longest common subsequence of two strings has been solved in quadratic time and space an algorithm is presented which will solve this problem in quadratic time and in linear space
CACM	efficient string matching an aid to bibliographic search this paper describes a simple efficient algorithm to locate all occurrences of any of a finite number of keywords in a string of text the algorithm consists of constructing a finite state pattern matching machine from the keywords and then using the pattern matching machine to process the text string in a single pass construction of the pattern matching machine takes time proportional to the sum of the lengths of the keywords the number of state transitions made by the pattern matching machine in processing the text string is independent of the number of keywords the algorithm has been used to improve the speed of a library bibliographic search program by a factor of 5 to 10
CACM	a simplified recombination scheme for the fibonacci buddy system a simplified recombination scheme for the fibonacci buddy system which requires neither tables nor repetitive calculations and uses only two additional bits per buffer is presented
CACM	indirect threaded code an efficient arrangement for interpretive code is described it is related to bells notion of threaded code but requires less space and is more amenable to machine independent implementations
CACM	significant event simulation this paper compares a new method of simulation organization called the significant event method with an old one called the clock pulse method using as examples two automobile traffic models the significant event method is found to be more efficient than the clock pulse method at low levels of system interaction and less efficient at high levels a simple mathematical model for the trade off in the relative running time of the two methods is developed the model aids in choosing between the two simulation methods for a particular experiment it is concluded that the significant event method can be of value in the simulation of some systems when computational efficiency is of sufficient importance
CACM	a cost oriented algorithm for data set allocation in storage hierarchies data set allocation in todays multilevel storage systems is usually based on qualitative ad hoc decisions while it would be desirable to obtain an optimal solution to this allocation problem it is clear that the number of parameters involved makes it intractable to straight forward solution in such a situation we must find a set of assumptions which simplify the problem greatly but which still provide a basis for considering all significant cost elements this paper presents such a first quantitative allocation step it considers many of the significant detailed costs of system utilization data storage data staging and data migration although many avenues of further improvement are available the present algorithm seems to be usefully accurate as such it can aid in quantifying the problems of data set allocation storage system configuration and new device designs
CACM	illumination for computer generated pictures the quality of computer generated images of three dimensional scenes depends on the shading technique used to paint the objects on the cathode ray tube screen the shading algorithm itself depends in part on the method for modeling the object which also determines the hidden surface algorithm the various methods of object modeling shading and hidden surface removal are thus strongly interconnected several shading techniques corresponding to different methods of object modeling and the related hidden surface algorithms are presented here human visual perception and the fundamental laws of optics are considered in the development of a shading rule that provides better quality and increased realism in generated images
CACM	generation of all the cycles of a graph from a set of basic cycles h algorithm 492
CACM	a heuristic problem solving design system for equipment or furniture layouts the designer problem solver dps demonstrates that the computer can perform simple design tasks in particular it designs furniture and equipment layouts this task was chosen because it is simple well defined and characteristic of many design tasks in architecture engineering urban planning and natural resource management these space planning tasks usually involve manipulating two dimensional representations of objects to create feasible or optimal solutions for problems involving topological and metric spatial constraints the paper describes extensive tests performed on the program dps is a heuristic problem solver with a planning phase prefixed to it it uses the planning process to give it a sense of direction diagnostic procedures to locate difficulties and remedial actions to recover from difficulties it uses a convex polygon representation to accurately describe the objects and the layout this representation allows topological and metric constraints to be tested and the design to be easily updated dps has been applied to 50 problems while it is slow and limited in scope the ideas behind it are general it demonstrates the need for selectivity in controlling search and the methods used to achieve it task specific information planning diagnostic procedures remedial actions and selective alternative generators
CACM	a syntactic algorithm for peak detection in waveforms with applications to cardiography peaks in a digitized waveform are detected by an algorithm incorporating piecewise linear approximation and tabular parsing techniques several parameters serve to identify the waveform context enabling accurate measurement of peak amplitude duration and shape the algorithm is of sufficient speed to allow on line real time processing an example of its application is demonstrated on an electrocardiogram
CACM	the new math of computer programming corrigendum
CACM	a problem list of public policy issues concerning computers and health care
CACM	more on kth shortest paths
CACM	a note on the lu factorization of a symmetric matrix
CACM	solution of an overdetermined system of equations in the l1 norm algorithm r478
CACM	visible surface plotting program algorithm r475
CACM	visible surface plotting program algorithm r475
CACM	ten subroutines for the manipulation of chebyshev series algorithm r446 c446
CACM	basic cycle generation h algorithm 491
CACM	an intelligent analyzer and understander of english the paper describes a working analysis and generation program for natural language which handles paragraph length input its core is a system of preferential choice between deep semantic patterns based on what we call semantic density the system is contrasted 1 with syntax oriented linguistic approaches and 2 with theorem proving approaches to the understanding problem
CACM	analysis and performance of inverted data base structures the need to envision and architecture data base systems in a hierarchical level by level framework is stressed the inverted data base file organization is then analyzed considering implementation oriented aspects the inverted directory is viewed realistically as another large data base which itself is subjected to inversion formulations are derived to estimate average access time read only and storage requirements formalizing the interaction of data base content characteristics logical complexity of queries and machine timing and blocking specifications identified as having a first order effect on performance the formulations presented are necessary to be used in conjunction with any index selection criteria to determine the optimum set of index keys
CACM	copying cyclic list structures in linear time using bounded workspace a bounded workspace copying algorithm for arbitrary list structures is given this algorithm operates in linear time and does not require tag bits the best previous bounded workspace copying algorithms achieved n 2 time without tag bits and n log n time with one tag the only restriction on the algorithm given here is that the copy must be placed into a contiguous section of memory the method is applicable to fixed or variable size nodes
CACM	a comparison of simulation event list algorithms four algorithms are considered which can be used to schedule events in a general purpose discrete simulation system two of the algorithms are new one is based on an end order tree structure for event notices and another uses an indexed linear list the algorithms are tested with a set of typical stochastic scheduling distributions especially chosen to show the advantages and limitations of the algorithms the end order tree algorithm is shown to be an advantageous immediate replacement for the algorithm in use with current simulation languages the most promising algorithm uses the indexed list concept it will require an adaptive routine before it can be employed in general purpose simulators but its performance is such that further study would be fruitful
CACM	an algorithm for locating adjacent storage blocks in the buddy system a simple scheme for the determination of the location of a block of storage relative to other blocks is described this scheme is applicable to the buddy type storage allocation systems
CACM	a modification of warshalls algorithm for the transitive closure of binary relations an algorithm is given for computing the transitive closure of a binary relation that is represented by a boolean matrix the algorithm is similar to warshalls although it executes faster for sparse matrices on most computers particularly in a paging environment
CACM	the quadratic hash method when the table size is not a prime number previous work on quadratic hash methods is limited mainly to the case where the table size is a prime number here certain results are derived for composite numbers it is shown that all composite numbers containing at least the square of one of the component primes have full period integer coefficient quadratic hash functions
CACM	the synthesis of solids bounded by many faces a technique is presented which allows a class of solid objects to be synthesized and stored using a computer synthesis begins with primitive solids like a cube wedge or cylinder any solid can be moved scaled or rotated solids may also be added together or subtracted two algorithms to perform addition are described for practical designers the technique has the advantage that operations are concise readily composed and are given in terms of easily imagined solids quite short sequences of operations suffice to build up complex solids bounded by many faces
CACM	on maintenance of the opportunity list for class teacher timetable problems one of the principal components of procedures for the solution of class teacher timetable problems is that for maintenance of the opportunity list opportunity list maintenance methods are based on necessary conditions for the existence of a solution a general framework for necessary conditions together with four specific sets of necessary conditions is given
CACM	a weighted buddy method for dynamic storage allocation corrigendum
CACM	remark on algorithm 475
CACM	the dilogarithm function of a real argument s22 algorithm 490
CACM	computer networks in higher education socio economic political factors this study presents the results of a nationwide survey of computer networks in higher education conducted during 1971 73 five major and 18 minor networks were identified the five major networks included the arpa net the california state college network the university of iowa iowa state university network the michigan educational research information triad inc and the triangle universities computation center network in north carolina in depth studies were conducted of the latter two nets based on the experiences of these operating networks a number of factors are identified for consideration in developing networks finally recommendations are advanced regarding the development of networks in higher education in the future
CACM	on a solution to the cigarette smokers problem without conditional statements this report discusses a problem first introduced by patil who has claimed that the cigarette smokers problem cannot be solved using the p and v operations introduced by dijkstra unless conditional statements are used an examination of patils proof shows that he has established this claim only under strong restrictions on the use of p and v these restrictions eliminate programming techniques used by dijkstra and others since the first introduction of the semaphore concept this paper contains a solution to the problem it also discusses the need for the generalized operators suggested by patil
CACM	perturbations of eigenvalues of non normal matrices corrigendum
CACM	discrete least squares polynomial fits the recurrence relation between orthogonal polynomials is widely used for discrete least squares data fitting a variant of the classical algorithm which has better numerical properties is presented and the reason for its improved performance is explained
CACM	on computing certain elements of the inverse of a sparse matrix a recursive algorithm for computing the inverse of a matrix from the lu factors based on relationships in takahashi et al is examined the formulas for the algorithm are given the dependency relationships are derived the computational costs are developed and some general comments on application and stability are made
CACM	the algorithm sequential access method an alternative to index sequential
CACM	a reply to gentleman and marovich
CACM	the algorithm select for finding the ith smallest of n elements m1 algorithm 489
CACM	expected time bounds for selection a new selection algorithm is presented which is shown to be very efficient on the average both theoretically and practically the number of comparisons used to select the ith smallest of n numbers is n min i n i o n a lower bound within 9 percent of the above formula is also derived
CACM	glypnir a programming language for illiac iv glypnir is one of the earliest existing languages designed for programming the illiac iv computer the syntax of the language is based on algol 60 but has been extended to allow the programmer explicitly to specify the parallelism of his algorithm in terms of 64 word vectors this paper describes the characteristics goals and philosophy of the language and discusses some of the problems associated with parallel computer architectures
CACM	a system for typesetting mathematics this paper describes the design and implementation of a system for typesetting mathematics the language has been designed to be easy to learn and to use by people for example secretaries and mathematical typists who know neither mathematics nor typesetting experience indicates that the language can be learned in an hour or so for it has few rules and fewer exceptions for typical expressions the size and font changes positioning line drawing and the like necessary to print according to mathematical conventions are all done automatically for example the input sum from i o to infinity x sub i pi over 2 produces formula the syntax of the language is specified by a small context free grammar a compiler compiler is used to make a compiler that translates this language into typesetting commands output maybe produced on either a phototypesetter or on a terminal with forward and reverse half line motions the system interfaces directly with text formatting programs so mixtures of text and mathematics may be handled simply this paper was typeset by the authors using the system described
CACM	matrix reduction an efficient method the paper describes an efficient method for reduction of the binary matrices which arise in some school time tabling problems it is a development of that described by john lions it has been generalized and adapted to fit into the complete timetabling process to use a more compact data representation and more efficient processing techniques to take fuller advantage of possible available previous knowledge about the matrix and it is designed as a structured program which can readily be coded by the reader in the high level or low level programming language of his choice practical tests of the method have shown it to be a good basis for a realistic timetabling algorithm
CACM	finding circles by an array of accumulators
CACM	a minimal spanning tree clustering method algorithm r479
CACM	the elementary circuits of a graph algorithm r459
CACM	exact probabilities for r x c contingency tables algorithm r434
CACM	jacobi polynomials algorithm r332
CACM	chi square quantiles algorithm c451
CACM	state space problem reduction and theorem proving some relationships this paper suggests a bidirectional relationship between state space and problem reduction representations it presents a formalism based on multiple input and multiple output operators which provides a basis for viewing the two types of representations in this manner a representation of the language recognition problem which is based on the cocke parsing algorithm is used as an illustration a method for representing problems in first order logic in such a way that the inference system employed by a resolution based theorem prover determines whether the set of clauses is interpreted in the state spacer mode or in the problem reduction mode is presented the analogous concepts in problem reduction and theorem proving and the terminology used to refer to them are noted the relationship between problem reduction input resolution and linear resolution is discussed
CACM	sentence paraphrasing from a conceptual base a model of natural language based on an underlying language free representation of meaning is described a program based on this model is able to produce sentence paraphrases which demonstrate understanding with respect to a given context this generator operates in conjunction with a natural language analyzer and a combined memory and inference model in generating sentences from meaning structures the program employs both the information retrieval and deduction capabilities of the memory model the model encompasses several diverse classes of linguistic knowledge which include 1 executable tests of conceptual properties stored in discrimination nets 2 information relating conceptual to syntactic roles stored in a word sense dictionary and 3 surface grammatical knowledge stored in a formal grammar
CACM	monitors an operating system structuring concept corrigendum
CACM	a first order approximation to the optimal checkpoint interval corrigendum
CACM	analysis of interleaved memory systems using blockage buffers a model of interleaved memory systems is presented and the analysis of the model by monte carlo simulation is discussed the simulations investigate the performance of various system structures i e schemes for sending instruction and data requests to the memory system performance is measured by determining the distribution of the number of memory modules in operation during a memory cycle an important observation from these investigations is that separately grouping instruction and data requests for memory can substantially increase the average number of memory modules in operation during a memory cycle results of the simulations and an analytical study are displayed for various system structures
CACM	stably updating mean and standard deviation of data by considering the sample mean of a set of data as a fit to this data by a constant function a computational method is given based on a matrix formulation and givens transformations the sample mean and standard deviation can be updated as data accumulates the procedure is numerically stable and does not require storage of the data methods for dealing with weighted data and data removal are presented when updating the mean and square of the standard deviation the process requires no square roots
CACM	connections between accuracy and stability properties of linear multistep formulas this paper is concerned with stability and accuracy of families of linear k step formulas depending on parameters with particular emphasis on the numerical solution of stiff ordinary differential equations an upper bound p k is derived for the order of accuracy of a inf  stable formulas three criteria are given for a 0  stability it is shown that 1 for p k k arbitrary a inf  stability implies certain necessary conditions for a 0  stability and for strict stability meaning that the extraneous roots of p psi satisfy psi 1 2 for p k 2 3 4 and 5 a inf  stability for k 5 together with another constraint implies strict stability and 3 for certain one parameter classes of formulas with p k 3 4 and or 5 a inf  stability implies a 0  stability
CACM	storage efficient representation of decimal data usually n decimal digits are represented by 4n bits in computers actually two bcd digits can be compressed optimally and reversibly into 7 bits and three digits into 10 bits by a very simple algorithm based on the fixed length combination of two variable field length encodings in over half of the cases the compressed code results from the conventional bcd code by simple removal of redundant 0 bits a long decimal message can be subdivided into three digit blocks and separately compressed the result differs from the asymptotic minimum length by only 0 34 percent the hardware requirement is small and the mappings can be done manually
CACM	the new math of computer programming structured programming has proved to be an important methodology for systematic program design and development structured programs are identified as compound function expressions in the algebra of functions the algebraic properties of these function expressions permit the reformulation expansion as well as reduction of a nested subexpression independently of its environment thus modeling what is known as stepwise program refinement as well as program execution finally structured programming is characterized in terms of the selection and solution of certain elementary equations defined in the algebra of functions these solutions can be given in general formulas each involving a single parameter which display the entire freedom available in creating correct structured programs
CACM	pseudoinverses and conjugate gradients this paper is devoted to the study of connections between pseudoinverses of matrices and conjugate gradients and conjugate direction routines
CACM	elementary divisors of tensor products the elementary divisors of a tensor product of linear transformations have been known for 40 years this paper provides a short easily accessible proof of these results and points out an interesting combinatorial consequence of the proof
CACM	perturbations of eigenvalues of non normal matrices the problem considered is to give bounds for finite perturbations of simple and multiple eigenvalues of nonnormal matrices where these bounds are in terms of the eigenvalues the departure from normality and the frobenius norm of the perturbation matrix but not in terms of the eigen system the bounds which are derived are shown to be almost attainable for any set of matrices
CACM	two hadamard numbers for matrices a discussion is given of two functions of the entries of a square matrix both related to hadamards determinant theorem which have some merits as alternatives to norm bound condition numbers one for linear systems is known the other for eigen systems seems to be new
CACM	on the stability of gauss jordan elimination with pivoting the stability of the gauss jordan algorithm with partial pivoting for the solution of general systems of linear equations is commonly regarded as suspect it is shown that in many respects suspicions are unfounded and in general the absolute error in the solution is strictly comparable with that corresponding to gaussian elimination with partial pivoting plus back substitution however when a is ill conditioned the residual corresponding to the gauss jordan solution will often be much greater than that corresponding to the gaussian elimination solution
CACM	the lemniscate constants the lemniscate constants and indeed some of the methods used for actually computing them have played an enormous part in the development of mathematics an account is given here of some of the methods used most of the derivations can be made by elementary methods this material can be used for teaching purposes and there is much relevant and interesting historical material the acceleration methods developed for the purpose of evaluating these constants are useful in other problems
CACM	positivity and norms following some lines of joint work with a s householder the character and use of algebraic methods in the theory of norms is demonstrated new results concerning norms with values in an archimedian vector lattice not necessarily being totally ordered are given in particular for the generalization of order unit norms l norms and m norms an example of application to operator norms is given concerning contraction properties of positive operators
CACM	professionalism in the computing field the term professional means different things to different people nevertheless there are certain general technical and social standards normally associated with a professional further the term is more generally applied to the practitioner rather than to the researcher but within the rather broad definition specified the computing practitioner is as yet not regarded as a professional each of the four types of institutions academic industry government and the professional society  that educate employ regulate and mold the practitioner contributes to the nonprofessional status of the computing practitioner the roles of these institutions are examined various shortcomings are noted and recommended changes are suggested in the last analysis professional status is not bestowed it is earned however universities and industry specifically can make certain improvements to help the computing practitioner achieve professional status
CACM	structural pattern recognition of carotid pulse waves using a general waveform parsing system a general waveform parsing system with application to structural pattern recognition of carotid pulse waves is described the carotid arterial pulse wave is of medical importance because of variation in its structure induced by arterial aging and cardiovascular disease the syntax driven waveform analysis system has been applied with good results to these pulse waves to detect and measure structural variations the waveform parsing system is modeled on a compiler compiler system and allows the user to enter application specific information as data it is thus general enough to be applicable to other waveforms
CACM	computer aided analysis and design of information systems this paper describes the use of computer aided analysis for the design and development of an integrated financial management system by the navy material command support activity nmcsa computer aided analysis consists of a set of procedures and computer programs specifically designed to aid in the process of applications software design computer selection and performance evaluation there are four major components problem statement language problem statement analyzer generator of alternative designs and performance evaluator the statement of requirements was written in ads accurately defined systems and analyzed by a problem statement analyzer for ads the ads problem definition was supplemented with additional information in order to create a complete problem definition the analyzed problem statement was translated to the form necessary for use by the soda systems optimization and design algorithm program for the generation of alternative specifications of program modules and logical database structures
CACM	the computer science and engineering research study cosers the computer science and engineering research study cosers is briefly described the motivation organization and schedule for this nsf supported study are given for possible further reference the subject area panel chairmen and the members of the steering committee are identified
CACM	roster of programming languages for 1974 75
CACM	high level binding with low level linkers an easy to implement scheme is described by which a compiler can enforce agreement between complex data types in separately compiled modules the scheme is designed to work with any existing link editor or linking loader no matter how deficient obscure run time errors caused by inconsistent usages are forestalled by static errors detected at linking time
CACM	optimal reorganization of distributed space disk files in most database organizations the cost of accessing the database will increase due to structural changes caused by updates and insertions by reorganizing the database the access costs can be reduced a basic problem is to establish the proper tradeoff between performance storage costs and reorganization costs this paper considers the optimum points at which to reorganize a database a disk file organization which allows for distributed free space is described a cost function describing the excess costs due to physical disorganization is defined and this function is minimized to obtain the optimum reorganization points numerical examples based on the characteristics of existing disk storage devices are given
CACM	the notions of consistency and predicate locks in a database system in database systems users access shared data under the assumption that the data satisfies certain consistency constraints this paper defines the concepts of transaction consistency and schedule and shows that consistency requires that a transaction cannot request new locks after releasing a lock then it is argued that a transaction needs to lock a logical rather than a physical subset of the database these subsets may be specified by predicates an implementation of predicate locks which satisfies the consistency condition is suggested
CACM	interference in multiprocessor computer systems with interleaved memory corrigendum
CACM	experiments in text file compression a system for the compression of data files viewed as strings of characters is presented the method is general and applies equally well to english to pl i or to digital data the system consists of an encoder an analysis program and a decoder two algorithms for encoding a string differ slightly from earlier proposals the analysis program attempts to find an optimal set of codes for representing substrings of the file four new algorithms for this operation are described and compared various parameters in the algorithms are optimized to obtain a high degree of compression for sample texts
CACM	the design and implementation of a table driven interactive diagnostic programming system caps is a highly interactive diagnostic compiler interpreter that allows beginning programmers to prepare debug and execute fairly simple programs at a graphics display terminal complete syntax checking and most semantic analysis is performed as the program is entered and as it is subsequently edited analysis is performed character by character the most remarkable feature of caps is its ability to automatically diagnose errors both at compile time and at run time errors are not automatically corrected instead caps interacts with the student to help him find the cause of his error most components of caps are table driven both to reduce the space needed for implementation and to increase the flexibility of the multilingual system over 500 students have used caps to learn fortran pl i or cobolin conjunction with a computer assisted course on introductory computer science
CACM	cobol under control a sample set of cobol programming standards is offered these standards constrain code to be developed in a structured form for both data and control structures they do not require syntax beyond the existing cobol language and in fact utilize a typical limited subset of the 1974 ans cobol standard these standards have proved extremely valuable in practice and have reduced the cost and time to produce and maintain large software systems that have been deployed in live multiple customer environments
CACM	homilies for humble standards copyright 1976 association for computing machinery inc general permission to republish but not for profit all or part of this material is granted provided that acms copyright notice is given and that reference is made to the publication to its data of issue and to the fact that reprinting privileges were granted by permission of the association for computing machinery
CACM	the status of women and minorities in academic computer science the results of a survey concerning women and minority students and faculty in computer science during the years 1971 to 1975 are presented analysis of the data indicated that effective affirmative action programs for recruitment into graduate degree programs are needed to enlarge the number of women and minorities qualified for later employment in computer science also possible discrimination in employment of women and minority graduate students was revealed
CACM	an improvement to martins algorithm for computation of linear precedence functions
CACM	the bmd and bmdp series of statistical computer programs
CACM	interactive skeleton techniques for enhancing motion dynamics in key frame animation a significant increase in the capability for controlling motion dynamics in key frame animation is achieved through skeleton control this technique allows an animator to develop a complex motion sequence by animating a stick figure representation of an image this control sequence is then used to drive an image sequence through the same movement the simplicity of the stick figure image encourages a high level of interaction during the design stage its compatibility with the basic key frame animation technique permits skeleton control to be applied selectively to only those components of a composite image sequence that require enhancement
CACM	a parametric algorithm for drawing pictures of solid objects composed of quadric surfaces an algorithm for drawing pictures of three dimensional objects with surfaces made up of patches of quadric surfaces is described the emphasis of this algorithm is on calculating the intersections of quadric surfaces a parameterization scheme is used each quadric surface intersection curve qsic is represented as a set of coefficients and parameter limits each value of the parameter represents at most two points and these may easily be distinguished this scheme can find the coordinates of points of even quartic fourth order intersection curves using equations of no more than second order methods of parameterization for each type of osic are discussed as well as surface bounding and hidden surface removal
CACM	hierarchical geometric models for visible surface algorithms the geometric structure inherent in the definition of the shapes of three dimensional objects and environments is used not just to define their relative motion and placement but also to assist in solving many other problems of systems for producing pictures by computer by using an extension of traditional structure information or a geometric hierarchy five significant improvements to current techniques are possible first the range of complexity of an environment is greatly increased while the visible complexity of any given scene is kept within a fixed upper limit second a meaningful way is provided to vary the amount of detail presented in a scene third clipping becomes a very fast logarithmic search for the resolvable parts of the environment within the field of view fourth frame to frame coherence and clipping define a graphical working set or fraction of the total structure that should be present in primary store for immediate access by the visible surface algorithm finally the geometric structure suggests a recursive descent visible surface algorithm in which the computation time potentially grows linearly with the visible complexity of the scene
CACM	texture and reflection in computer generated images in 1974 catmull developed a new algorithm for rendering images of bivariate surface patches this paper describes extensions of this algorithm in the areas of texture simulation and lighting models the parameterization of a patch defines a coordinate system which is used as a key for mapping patterns onto the surface the intensity of the pattern at each picture element is computed as a weighted average of regions of the pattern definition function the shape and size of this weighting function are chosen using digital signal processing theory the patch rendering algorithm allows accurate computation of the surface normal to the patch at each picture element permitting the simulation of the mirror reflections the amount of light coming from a given direction is modeled in a similar manner to the texture mapping and then added to the intensity obtained from the texture mapping several examples of images synthesized using these new techniques are included
CACM	a practitioners guide to addressing algorithms corrigendum
CACM	analysis of the pff replacement algorithm via a semi markov model corrigendum
CACM	faster retrieval from context trees corrigendum context trees provide a convenient way of storing data which is to be viewed as a hierarchy of contexts this note presents an algorithm which improves on previous context tree retrieval algorithms it is based on the observation that in typical uses context changes are infrequent relative to retrievals so that data can be cached to speed up retrieval a retrieval is started from the position of the previous retrieval and auxiliary structures are built up to make the search rapid algorithms for addition and deletion of data and for garbage collection are outlined
CACM	an efficient incremental automatic garbage collector this paper describes a new way of solving the storage reclamation problem for a system such as lisp that allocates storage automatically from a heap and does not require the programmer to give any indication that particular items are no longer useful or accessible a reference count scheme for reclaiming non self referential structures and a linearizing compacting copying scheme to reorganize all storage at the users discretion are proposed the algorithms are designed to work well in systems which use multiple levels of storage and large virtual address space they depend on the fact that most cells are referenced exactly once and that reference counts need only be accurate when storage is about to be reclaimed a transaction file stores changes to reference counts and a multiple reference table stores the count for items which are referenced more than once
CACM	efficient generation of the binary reflected gray code and its applications algorithms are presented to generate the n bit binary reflected gray code and codewords of fixed weight in that code both algorithms are efficient in that the time required to generate the next element from the current one is constant applications to the generation of the combinations of n things taken k at a time the compositions of integers and the permutations of a multiset are discussed
CACM	recursion analysis for compiler optimization a relatively simple method for the detection of recursive use of procedures is presented for use in compiler optimization implementation considerations are discussed and a modification of the algorithm is given to further improve optimization this analysis can also be used to determine what possible subset of values could be assumed by variables which can only take on a relatively small discrete set of values the most common are parameters of variables assuming values of label procedure or pascals enumerated type
CACM	weighted derivation trees the nodes of a weighted derivation tree are associated with weighting functions over the vocabulary of a context free grammar an algorithm is presented for constructing the optimal derivation tree having the same structure as a given weighted derivation tree in addition the correctness of the algorithm is established the method may be applied to problems involving probabilistic parsing or combinatorial optimization
CACM	new upper bounds for selection the worst case minimum number of comparisons complexity vi n of the i th selection problem is considered a new upper bound for vi n improves the bound given by the standard hadian sobel algorithm by a generalization of the kirkpatrick hadian sobel algorithm and extends kirkpatricks method to a much wider range of application this generalization compares favorably with a recent algorithm by hyafil
CACM	analysis of an algorithm for real time garbage collection a real time garbage collection system avoids suspending the operations of a list processor for the long times that garbage collection normally requires by performing garbage collection on a second processor in parallel with list processing operations or on a single processor time shared with them algorithms for recovering discarded list structures in this manner are presented and analyzed to determine sufficient conditions under which the list processor never needs to wait on the collector these techniques are shown to require at most twice as much processing power as regular garbage collectors if they are used efficiently the average behavior of the program is shown to be very nearly equal to the worst case performance so that the sufficient conditions are also suitable for measuring the typical behavior of the algorithm
CACM	an insertion technique for one sided height balanced trees a restriction on height balanced binary trees is presented it is seen that this restriction reduces the extra memory requirements by half from two extra bits per node to one and maintains fast search capabilities at a cost of increased time requirements for inserting new nodes
CACM	protection in operating systems a model of protection mechanisms in computing systems is presented and its appropriateness is argued the safety problem for protection systems under this model is to determine in a given situation whether a subject can acquire a particular right to an object in restricted cases it can be shown that this problem is decidable i e there is an algorithm to determine whether a system in a particular configuration is safe in general and under surprisingly weak assumptions it cannot be decided if a situation is safe various implications of this fact are discussed
CACM	designing surfaces in 3 d an experimental system for computer aided design of free form surfaces in three dimensions is described the surfaces are represented in the system as parametric basis splines the principal features of the system are 1 the surfaces are rendered as isoparametric line drawings on a head mounted display and they are designed with the aid of a three dimensional wand which allows 3 d movements of the points controlling the shapes of the surfaces 2 all of the interactions with the surfaces are in real time and 3 the mathematical formulations used assume no knowledge of them by the user of the system also examined are some of the features that should be part of a practical 3 d system for designing space forms
CACM	the denotational semantics of programming languages this paper is a tutorial introduction to the theory of programming language semantics developed by d scott and c strachey the application of the theory to formal language specification is demonstrated and other applications are surveyed the first language considered loop is very elementary and its definition merely introduces the notation and methodology of the approach then the semantic concepts of environments stores and continuations are introduced to model classes of programming language features and the underlying mathematical theory of computation due to scott is motivated and outlined finally the paper presents a formal definition of the language gedanken
CACM	tools and philosophy for software education this paper describes a set of tools and a philosophy for teaching software that have been found very useful in course at mit over the past seven years the tools include programs such as simulators graders compilers and monitor these allow the instructor to augment the basic concepts with relevant exciting and economical student project activities
CACM	heaps applied to event driven mechanisms
CACM	a buddy system variation for disk storage allocation a generalization of the buddy system for storage allocation is described the set of permitted block sizes size i i 0 n must satisfy the condition size i size i 1 size i k i where k may be any meaningful integral valued function this makes it possible to force logical storage blocks to coincide with physical storage blocks such as tracks and cylinders
CACM	compressed tries this paper presents a new data structure called a compressed trie or c trie to be used in information retrieval systems it has the same underlying m ary tree structure as a trie where m is a parameter of the trie but whereas the fields of the nodes in a trie have to be large enough to hold a key or at least a pointer the fields in a c trie are only one bit long in the analysis part of the paper it will be shown that for a collection of n keys the retrieval time measured in terms of bit inspections of one key is of the order logm n and the storage requirement of the order n m log2 n bits this improvement in storage requirements and retrieval time is achieved at the cost of decreasing the flexibility of the structure and therefore updating costs are increased first the c trie is analyzed as a data structure and then several methods of its use for relatively static databases are discussed
CACM	sampling from the gamma distribution on a computer this paper describes a method of generating gamma variates that appears to be less costly than wallaces recently suggested method for large shape parameter a the cost of computation is proportional to a whereas wallaces method is proportional to a experimentation by robinson and lewis indicates that for small a the method suggested here also dominates methods recently suggested by dieter and ahrens albeit those methods dominate for large a the method suggested here uses the rejection technique
CACM	synthesis of decision rules decision tables can be used as an effective tool during an interview to record the logic of processes to be automated the result of such an interview is not a structure of complete decision tables but rather sets of decision rules the purpose of this paper is to provide a procedure for synthesizing the decision rules and thus provide an aid in developing a structure of complete decision tables
CACM	ethernet distributed packet switching for local computer networks ethernet is a branching broadcast communication system for carrying digital data packets among locally distributed computing stations the packet transport mechanism provided by ethernet has been used to build systems which can be viewed as either local computer networks or loosely coupled multiprocessors an ethernets shared communication facility its ether is a passive broadcast medium with no central control coordination of access to the ether for packet broadcasts is distributed among the contending transmitting stations using controlled statistical arbitration switching of packets to their destinations on the ether is distributed among the receiving stations using packet address recognition design principles and implementation are described based on experience with an operating ethernet of 100 nodes along a kilometer of coaxial cable a model for estimating performance under heavy loads and a packet protocol for error controlled communication are included for completeness
CACM	symbolic execution and program testing this paper describes the symbolic execution of programs instead of supplying the normal inputs to a program e g numbers one supplies symbols representing arbitrary values the execution proceeds as in a normal execution except that values may be symbolic formulas over the input symbols the difficult yet interesting issues arise during the symbolic execution of conditional branch type statements a particular system called effigy which provides symbolic execution for program testing and debugging is also described it interpretively executes programs written in a simple pl i style programming language it includes many standard debugging features the ability to manage and to prove things about symbolic expressions a simple program testing manager and a program verifier a brief discussion of the relationship between symbolic execution and program proving is also included
CACM	formal verification of parallel programs two formal models for parallel computation are presented an abstract conceptual model and a parallel program model the former model does not distinguish between control and data states the latter model includes the capability for the representation of an infinite set of control states by allowing there to be arbitrarily many instruction pointers or processes executing the program an induction principle is presented which treats the control and data state sets on the same ground through the use of place variables it is observed that certain correctness conditions can be expressed without enumeration of the set of all possible control states examples are presented in which the induction principle is used to demonstrate proofs of mutual exclusion it is shown that assertions oriented proof methods are special cases of the induction principle a special case of the assertions method which is called parallel place assertions is shown to be incomplete a formalization of deadlock is then presented the concept of a norm is introduced which yields an extension to the deadlock problem of floyds technique for proving termination also discussed is an extension of the program model which allows each process to have its own local variables and permits shared global variables correctness of certain forms of implementation is also discussed an appendix is included which relates this work to previous work on the satisfiability of certain logical formulas
CACM	the technology of computer center management a proposed course for graduate professional programs in computer science or in information systems mcfarlan and nolan have made a strong case for adding a course on information systems administration to the 13 courses proposed by the acm curriculum committee on computer education for management for graduate professional programs in information systems this paper is a report on a course entitled the technology of computer center management which has been offered at purdue for the past four years the course is suitable either for graduate professional programs in information systems or for graduate professional programs in computer science
CACM	a numbering system for permutations of combinations
CACM	multiprocessing compactifying garbage collection corrigendum
CACM	an efficient list moving algorithm using constant workspace an efficient algorithm is presented for moving arbitrary list structures using no storage apart from program variables other than that required to hold the original list and the copy the original list is destroyed as it is moved no mark bits are necessary but pointers to the copy must be distinguishable from pointers to the original the algorithm is superior in execution speed to previous algorithms for the same problem some variations and extensions of the algorithm are discussed
CACM	the synthetic approach to decision table conversion previous approaches to the problem of automatically converting decision tables to computer programs have been based on decomposition at any stage one condition is selected for testing and two smaller problems decision tables with one less condition are created an optimal program with respect to average execution time or storage space for example is located only through implicit enumeration of all possible decision trees using a technique such as branch and bound the new approach described in this paper uses dynamic programming to synthesize an optimal decision tree from which a program can be created using this approach the efficiency of creating an optimal program is increased substantially permitting generation of optimal programs for decision tables with as many as ten to twelve conditions
CACM	referencing lists by an edge an edge reference into a list structure is a pair of pointers to adjacent nodes such a reference often requires little additional space but its use can yield efficient algorithms for instance a circular link between the ends of a list is redundant if the list is always referenced by that edge and list traversal is easier when that link is null edge references also allow threading of nonrecursive lists can replace some header cells and enhance the famous exclusive or trick to double link lists
CACM	a process for the determination of addresses in variable length addressing an algorithm is presented for the assignment of instruction addresses and formats under the following conditions 1 the length of the instruction varies as a function of the distance of the instruction from its target 2 there exists an optimality criterion which implies some preferential choices subject to the addressing constraints this may be for example achieving the smallest number of long instructions in which case the total code length is minimized or minimizing the assigned address of a specified point in the program the algorithm is suitable for arbitrary program structure and a choice of optimization criteria
CACM	interference in multiprocessor computer systems with interleaved memory this paper analyzes the memory interference caused by several processors simultaneously using several memory modules exect results are computed for a simple model of such a system the limiting value is derived for the relative degree of memory interference as the system size increases the model of the limiting behavior of the system yields approximate results for the simple model and also suggests that the results are valid for a much larger class of models including those more nearly like real systems that the simple model are tested against some measurements of program behavior and simulations of systems using memory references from real programs the model results provide a good indication of the performance that should be expected from real system of this type
CACM	a practitioners guide to addressing algorithms this paper consolidates a number of popular rules of thumb which have been suggested for the design of record addressing algorithms and discusses the applicability of these rules to large commercial databases guidelines for selecting identifier transformations overflow techniques loading factors bucket sizes and loading order and considered particular attention is focused on the reasonableness of common heuristics for determining primary or secondary bucket sizes a mathematical model which explicitly considers storage device characteristics and time space cost tradeoffs is used to analyze the effect of design parameters on overall system costs a specific design example is presented and solved
CACM	production and employment of ph d s in computer science
CACM	analysis of the pff replacement algorithm via a semi markov model an analytical model is presented to estimate the performance of the page fault frequency pff replacement algorithm in this model program behavior is represented by the lru stack distance model and the pff replacement algorithm is represented by a semi markov model using these models such parameters as the inter page fault interval distribution the probability of the number of distinct pages being referenced during an inter page fault interval etc are able to be analytically determined using these models to evaluate these parameter values permits study of the performance of the replacement algorithm by simulating the page fault events rather than every page reference event this significantly reduces the required computation time in estimating the performance of the pff algorithm
CACM	vmin an optimal variable space page replacement algorithm a criterion for comparing variable space page replacement algorithms is presented an optimum page replacement algorithm called vmin is described and shown to be optimum with respect to this criterion the results of simulating vmin dennings working set and the page partitioning replacement algorithms on five virtual memory programs are presented to demonstrate the improvement possible over the known realizable variable space algorithms
CACM	characteristics of program localities the term locality has been used to denote that subset of a programs segments which are referenced during a particular phase of its execution a programs behavior can be characterized in terms of its residence in localities of various sizes and lifetimes and the transitions between these localities in this paper the concept of a locality is made more explicit through a formal definition of what constitutes a phase of localized reference behavior and by a corresponding mechanism for the detection of localities in actual reference strings this definition provides for the existence of a hierarchy of localities at any given time and the reasonableness of the definition is supported by examples taken from actual programs empirical data from a sample of production algol 60 programs is used to display distributions of locality sizes and lifetimes and these results are discussed in terms of their implications for the modeling of program behavior and memory management in virtual memory systems
CACM	verifying properties of parallel programs an axiomatic approach an axiomatic method for proving a number of properties of parallel programs is presented hoare has given a set of axioms for partial correctness but they are not strong enough in most cases this paper defines a more powerful deductive system which is in some sense complete for partial correctness a crucial axiom provides for the use of auxiliary variables which are added to a parallel program as an aid to proving it correct the information in a partial correctness proof can be used to prove such properties as mutual exclusion freedom from deadlock and program termination techniques for verifying these properties are presented and illustrated by application to the dining philosophers problem
CACM	proving monitors interesting scheduling and sequential properties of monitors can be proved by using state variables which record the monitors history and by defining extended proof rules for their wait and signal operations these two techniques are defined discussed and applied to examples to prove properties such as freedom from indefinitely repeated overtaking or unnecessary waiting upper bounds on queue lengths and historical behavior
CACM	modularization and hierarchy in a family of operating systems this paper describes the design philosophy used in the construction of a family of operating systems it is shown that the concepts of module and level do not coincide in a hierarchy of functions family members can share much software as a result of the implementation of run time modules at the lowest system level
CACM	reflections on an operating system design the main features of a general purpose multiaccess operating system developed for the cdc 6400 at berkeley are presented and its good and bad points are discussed as they appear in retrospect distinctive features of the design were the use of capabilities for protection and the organization of the system into a sequence of layers each building on the facilities provided by earlier ones and protecting itself from the malfunctions of later ones there were serious problems in maintaining the protection between layers when levels were added to the memory hierarchy these problems are discussed and a new solution is described
CACM	security kernel validation in practice a security kernel is a software and hardware mechanism that enforces access controls within a computer system the correctness of a security kernel on a pdp 11 45 is being proved this paper describes the technique used to carry out the first step of the proof validating a formal specification of the program with respect to a axioms for a secure system
CACM	a lattice model of secure information flow this paper investigates mechanisms that guarantee secure information flow in a computer system these mechanisms are examined within a mathematical framework suitable for formulating the requirements of secure information flow among security classes the central component of the model is a lattice structure derived from the security classes and justified by the semantics of information flow the lattice properties permit concise formulations of the security requirements of different existing systems and facilitate the construction of mechanisms that enforce security the model provides a unifying view of all systems that restrict information flow enables a classification of them according to security objectives and suggests some new approaches it also leads to the construction of automatic program certification mechanisms for verifying the secure flow of information through a program
CACM	logical analysis of programs most present systems for verification of computer programs are incomplete in that intermediate inductive assertions must be provided manually by the user termination is not proven and incorrect programs are not treated as a unified solution to these problems this paper suggests conducting a logical analysis of programs by using invariants which express what is actually occurring in the program the first part of the paper is devoted to techniques for the automatic generation of invariants the second part provides criteria for using the invariants to check simultaneously for correctness including termination or incorrectness a third part examines the implications of the approach for the automatic diagnosis and correction of logical errors
CACM	a counterintuitive example of computer paging corrigendum
CACM	lg a language for analytic geometry a conversational programming language for analytic geometry is described together with some aspects of its implementation the language allows the flexible definition of geometric objects and elements computes their parameters and displays the results it also provides the capability of specifying a geometric figure via a collection of parameters and displaying various loci corresponding to these parameters a third characteristic consists of the possibility of using this language to design other user oriented languages lg has been specifically designed for use by nonprogrammers it is easy to learn and very close to the natural language used in geometry
CACM	a comparative evaluation of versions of basic from its inception the basic language has grown in terms of its usage scope of usage and its features this article compares ten of the current versions of basic with each other with two earlier versions and with the proposed standard for minimal basic the comparison is arranged by the features of the versions and by computational comparison of computation and times and processing costs
CACM	development of an international system for legal protection of computer programs
CACM	intentional resolution of privacy protection in database systems traditionally privacy protection in database systems is understood to be the control over what information a given user can get from a database this paper is concerned with another independent dimension of privacy protection the control over what a user is allowed to do with a piece of information supplied to him by the database the ability to condition the supply of information on its intended use is called here intentional resolution of privacy protection the practical importance of intentional resolution is demonstrated by several examples and its realization is discussed it is shown that intentional resolution can be achieved but that it involves a radical change from the traditional approach to the process of user database interaction in particular it appears to be necessary for the database to impose a certain amount of control over the internal behavior of users programs which interact with it a model for user database interaction which admits such a control is developed
CACM	a program data flow analysis procedure the global data relationships in a program can be exposed and codified by the static analysis methods described in this paper a procedure is given which determines all the definitions which can possibly reach each node of the control flow graph of the program and all the definitions that are live on each edge of the graph the procedure uses an interval ordered edge listing data structure and handles reducible and irreducible graphs indistinguishably
CACM	joining policies in a multipriority multiclass batch computer system consider a multipriority batch computer system which users from several different classes may join its toll service and waiting charges such a system is formulated here as a semi markov decision process in which the aim of arriving users is to minimize their expected loss the optimal joining policy is one of arriving users who may join the system at some of its queues is a control limit policy with a single control number for any possible queue and the users class a newly arriving user will join a queue that is not filled up to the control number corresponding to this queue and the users class in this paper control numbers as well as lower and upper bounds for the control numbers and the capacities of the systems queues are derived
CACM	computer science as empirical inquiry symbols and search
CACM	a fast division technique for constant divisors a fast algorithm for division by constant divisors is presented the method has proved very useful implemented as microcode ona binary machine and can be adapted directly into hardware the mathematical foundations of the algorithm are presented as well as some performance measures
CACM	a counterintuitive example of computer paging a counterexample is exhibited to a natural conjecture concerning the optimal way to group records into pages in the independent reference model of computer paging an organization is said to be optimal if the least recently used miss ratio is minimized
CACM	a stochastic evaluation model for database organization in data retrieval systems experimental work in the valuation of large scale data retrieval systems has been scarce due to its difficulty and prohibitive cost this paper discusses a simulation model of a data retrieval system which has the effect of significantly reducing the cost of experimentation and enabling research never attempted before the model is designed to estimate the retrieval workload of alternative data retrieval systems these data retrieval systems can be organized under several database organizations including inverted list threaded list and cellular list organizations and hybrid combinations of these systems effectiveness of the methodology is demonstrated by using the model to study the effect of database organizations in data retrieval systems in particular the impact of query complexity is analyzed
CACM	an application of heuristic search methods to edge and contour detection this paper presents a method for detecting edges and contours in noisy pictures the properties of an edge are embedded in a figure of merit and the edge detection problem becomes the problem of minimizing the given figure of merit this problem can be represented as a shortest path problem on a graph and can be solved using well known graph search algorithms the relations between this representation of the minimization problem and a dynamic programming approach are discussed showing that the graph search method can lead to substantial improvements in computing time moreover if heuristic search methods are used the computing time will depend on the amount of noise in the picture some experimental results are given these show how various information about the shape of the contour of an object can be embedded in the figure of merit thus allowing the extraction of contours from noisy picture and the separation of touching objects
CACM	permutation enumeration four new permutation algorithms classical permutation enumeration algorithms encounter special cases requiring additional computation every nth permutation when generating the n permutations on n marks four new algorithms have the attribute that special cases occur every n n 1 permutations two of the algorithms produce the next permutation with a single exchange of two marks the other two algorithms infrequently exchange more than two marks but the rules for generating the next permutation are very simple performance tests which have counted execution of assignment statements comparisons arithmetic operations and subscripted array references have shown superiority of the new algorithms compared to boothroyds implementation of m b wells algorithm and ehrlichs implementation of the johnson trotter algorithm
CACM	on self organizing sequential search heuristics this paper examines a class of heuristics for maintaining a sequential list in approximately optimal order with respect to the average time required to search for a specified element assuming that each element is searched for with a fixed probability independent of previous searches performed the move to front and transposition heuristics are shown to be optimal to within a constant factor and the transposition rule is shown to be the more efficient of the two empirical evidence suggests that transposition is in fact optimal for any distribution of search probabilities
CACM	semantic evaluation from left to right this paper describes attribute grammars and their use for the definition of programming languages and compilers a formal definition of attribute grammars and a discussion of some of its important aspects are included the paper concentrates on the evaluation of semantic attributes in a few passes from left to right over the derivation tree of a program a condition for an attribute grammar is given which assures that the semantics of any program can be evaluated in a single pass over the derivation tree and an algorithm is discussed which decides how many passes from left to right are in general necessary given the attribute grammar these notions are explained in terms of an example grammar which describes the scope rules of algol 60 practical questions such as the relative efficiency of different evaluation schemes and the ease of adapting the attribute grammar of a given programming language to the left to right evaluation scheme are discussed
CACM	a study of errors error proneness and error diagnosis in cobol this paper provides data on cobol error frequency for correction of errors in student oriented compilers improvement of teaching and changes in programming language cobol was studied because of economic importance widespread usage possible error including design and lack of research the types of errors were identified in a pilot study then using the 132 error types found 1 777 errors were classified in 1 4000 runs of 73 cobol students error density was high 20 percent of the types contained 80 percent of the total frequency which implies high potential effectiveness for software based correction of cobol surprisingly only four high frequency errors were error prone which implies minimal error inducing design 80 percent of cobol misspellings were classifiable in the four error categories of previous researchers which implies that cobol misspellings are correctable by existent algorithms reserved word usage was not error prone which implies minimal interference with usage of reserved words over 80 percent of error diagnosis was found to be inaccurate such feedback is not optimal for users particularly for the learning user of cobol
CACM	information reference coding items in business systems have to be identified by reference codes which can later be used as data codes and file keys in an associated data processing system in business systems associated with large collections of integrated files database it is vital to assign codes in a methodical way so as to control future extension and changes while maintaining correct program action the principles of methodical coding are discussed and the way in which logical connections between data items must be reflected in the reference code framework is shown through a set theoretic information model
CACM	performance of height balanced trees this paper presents the results of simulations that investigate the performance of height balanced hb k trees it is shown that the only statistic of hb 1 trees avl trees that is a function of the size of the tree is the time to search for an item in the tree for sufficiently large trees the execution times of all procedures for maintaining hb 1 trees are independent of the size of the tree in particular an average of 465 restructures are required per insertion with an average of 2 78 nodes revisited to restore the hb 1 property an average of 214 restructures are required per deletion with an average of 1 91 nodes revisited to restore the hb 1 property moreover the execution times of procedures for maintaining hb k trees for k 1 are also independent of the size of the tree except for the average number of nodes revisited on a delete operation in order to restore the hb k property on trace back the cost of maintaining hb k trees drops sharply as the allowable imbalance k increases both analytical and experimental results that show the cost of maintaining hb k trees as a function of k are discussed
CACM	on quadratic adaptive routing algorithms two analytic models of a store and forward communications network are constructed one to find the optimal message routing and the other to illustrate the equilibrium stationary state maintained by an adaptive routing algorithm these models show that adaptive routing does not satisfy the necessary conditions for an optimal routing adaptive routing tends to overuse the direct path and underuse alternate routes because it does not consider the impact of its current routing decision on the future state of the network the form of the optimality conditions suggests that a modification of the adaptive algorithm will result in optimality the modification requires the substitution of a quadratic bias term instead of a linear one in the routing table maintained at each network node simulation results are presented which confirm the theoretical analysis for a simple network
CACM	an anomaly in disk scheduling a comparison of fcfs and sstf seek scheduling using an empirical model for disk accesses a model for disk accesses based on published measurements is developed the model is used to show that under highly probable conditions fcfs seek scheduling is superior to sstf scheduling in the sense of having a lower mean queue length a simple example of an arrival sequence illustration this anomaly is presented
CACM	a study of line overhead in the arpanet the form extent and effect of the communication line overhead in the arpanet are considered the source of this over head is separated into various levels of protocol hierarchy and the characteristics of each level are summarized then the line efficiency for various models of system use is studied some measurements of line efficiency for the arpanet are presented and by extrapolation these measurements are used to anticipate overhead in a heavily loaded network similar results are derived for a recently proposed network protocol and compared with those for the current system
CACM	computers as an innovation in american local governments computers and electronic data processing are a major technological innovation in the operations of american local government this paper establishes that there is substantial variation among the larger local governments in the rate at which they adopt computer technology in the level of financial support they provide for edp and in the extensiveness and sophistication of their automated applications the central question addressed is what might explain the differences between governments in the extent to which they adopt and use computers hypotheses are tested for several streams of explanatory factors using data from more than 500 city and county governments the findings identify certain local government milieus which are particularly conducive to higher levels of computer innovation somewhat unexpected findings reveal the significant impact of the distribution of control over edp decisions and the dominant political values within the government other important factors include the measured need for computer applications and the presence of external funding support for computing finally the paper suggests a framework for identifying the key determinants of other technological innovations
CACM	a methodology for interactive computer service measurement a measurement methodology applicable to in teractive computer service is described its primary purpose is to enable external user oriented assessment of computer performance instead of the more frequently used in ternal system measurement techniques the nbs network measurement system is employed as the external measurement tool example data have been collected and analyzed a demonstration of the methodology leading to a pragmatic figure of merit evaluation of results is included
CACM	a language for formal problem specification a language for specifying the in tended behavior of communicating parallel processes is described the specifications are constrain ts on the order in which events of a computation can occur the language is used to write specifications of the readers writers problem and the writer priority of the second readers writers problem
CACM	an exercise in proving parallel programs correct a parallel program dijkstras on the fly garbage collector is proved correct using a proof method developed by owicki the fine degree of in terleaving in this program makes it especially difficult to understand and complicates the proof greatly difficulties with proving such parallel programs correct are discussed
CACM	a case study of a new code generation technique for compilers recent developments in optimizing techniques have allowed a new design for compilers to emerge such a compiler translates the parsed source code into lower level code by a sequence of steps each step expands higher level statements into blocks of lower level code and then performs optimizations on the result each statement has only one possible expansion the task of tailoring this code to take advantage of any special cases is done by the optimizations this paper provides evidence that this strategy can indeed result in good object code the traditionally difficult pl i concatenate statement was investigated as a detailed example a set of fairly simple optimizations was identified which allow the compiler to produce good code more elaborate optimizations can further improve the object code for most contexts of the concatenate statement the code produced by a compiler using the expansion optimization strategy described above compares favorably with the code produced by a conventional pl i optimizing compiler
CACM	a conceptual framework for a nonprocedural programming language a sequential programming language forces the programmer to prescribe explicitly the order in which the operations in his program have to be executed even if the order is not relevant to the solution of his problem the requirement to indicate irrelevant sequencing can be removed if the language provides facilities for specifying a task in a nonprocedural manner in general a program specified in this way will allow concurrent evaluation this paper describes a conceptual framework for a high level programming language providing both nonprocedural and sequential facilities within a program nonprocedural and sequential program modules may be nested freely
CACM	a survey of computer science offerings in small liberal arts colleges recent curricular development in computer science together with student in terest in pursuing topics in computer science beyond the usual programming courses have encouraged small liberal arts colleges to expand their offerings this paper summarizes the results of a survey taken to determine the type of computer science programs being offered in these colleges the results indicate that over half of these colleges either have no computer science program or offer only programming courses
CACM	some theorems to aid in solving the file allocation problem the file allocation problem i e the problem of finding the optimal set of network sites at which to locate copies of a file is known to be in general polynomial complete heuristics and other aids to finding optimal or near optimal solutions are therefore much needed in this paper we present three theorems which can be applied a priori to indicate that certain sites should or should not be included in an optimal allocation
CACM	an encoding method for multifield sorting and indexing sequences of character strings with an order relation imposed between sequences are considered an encoding scheme is described which produces a single order preserving string from a sequence of strings the original sequence can be recovered from the encoded string and one sequence of strings precedes another if and only if the encoding of the first precedes the encoding of the second the strings may be variable length without a maximum length restriction and no symbols need be reserved for control purposes hence any symbol may occur in any string the scheme is useful for multifield sorting multifield indexing and other applications where ordering on more than one field is important
CACM	dynamic memory allocation in computer simulation this paper investigates the performance of 35 dynamic memory allocation algorithms when used to service simulation programs as represented by 18 test cases algorithm performance was measured in terms of processing time memory usage and external memory fragmentation algorithms main taining separate free space lists for each size of memory block used tended to perform quite well compared with other algorithms simple algorithms operating on memory ordered lists without any free list performed surprisingly well algorithms employing power of two block sizes had favorable processing requirements but generally unfavorable memory usage algorithms employing lifo fifo or memory ordered free lists generally performed poorly compared with others
CACM	improving programs by the introduction of recursion a new technique of program transformation called recursion in troduction is described and applied to two algorithms which solve pattern matching problems by using recursion in troduction algorithms which manipulate a stack are first translated into recursive algorithms in which no stack operations occur these algorithms are then subjected to a second transformation a method of recursion elimination called tabulation to produce programs with a very efficient running time in particular it is shown how the fast linear pattern matching algorithm of knuth morris and pratt can be derived in a few steps from a simple nonlinear stack algorithm
CACM	an algorithm for reduction of operator strength a simple algorithm which uses an indexed temporary table to perform reduction of operator strength in strongly connected regions is presented several extensions including linear function test replacement are discussed these algorithms should fit well into an integrated package of local optimization algorithms
CACM	perfect hashing functions a single probe retrieving method for static sets a refinement of hashing which allows retrieval of an item in a static table with a single probe is considered given a set i of identifiers two methods are presented for building in a mechanical way perfect hashing functions i e functions transforming the elements of i into unique addresses the first method the quotient reduction method is shown to be complete in the sense that for every set i the smallest table in which the elements of i can be stored and from which they can be retrieved by using a perfect hashing function constructed by this method can be found however for nonuniformly distributed sets this method can give rather sparse tables the second method the remainder reduction method is not complete in the above sense but it seems to give minimal or almost minimal tables for every kind of set the two techniques are applicable directly to small sets some methods to extend these results to larger sets are also presented a rough comparison with ordinary hashing is given which shows that this method can be used conveniently in several practical applications
CACM	a very high level programming language for data processing applications application development today is too labor in tensive in recent years very high level languages have been increasingly explored as a solution to this problem the business definition language bdl is such a language one aimed at business data processing problems the concepts in bdl mimic those which have evolved through the years in businesses using manual methods this results in three different sublanguages or components one for defining the business forms one for describing the business organization and one for writing calculations
CACM	the optimal approach to recursive programs the classical fixed poin t approach toward recursive programs suggests choosing the least defined fixed poin t as the most appropriate solution to a recursive program a new approach is described which in troduction an optimal fixed point which in contrast to the least defined fixed poin t embodies the maximal amount of valuable information embedded in the program the practical implications of this approach are discussed and techniques for proving properties of optimal fixed poin t are given the presentation is informal with emphasis on examples
CACM	a note on reflection free permutation enumeration
CACM	what can we do about the unnecessary diversity of notation for syntactic definitions
CACM	equivalence of hough curve detection to template matching
CACM	anomalous behavior of the fifty percent rule in dynamic memory allocation this paper reports simulation data showing that in dynamic memory allocation the average free to allocated block ratio can differ considerably and in both directions from the predictions of the 50 percent rule a new derivation is given and it is shown that previous derivations make an assumption that may be violated frequently on the basis of the simulation data and the derivation it is hypothesized that the anomalous behavior results from the combined effects of systematic placement and the statistics of the release process additional simulations support this hypothesis systematic placement which refers to the natural convention of always allocating storage requests against the same end of the free block selected by the allocation strategy tends to order blocks within contiguous groups according to their allocation time the degree of anomalous behavior depends on the extent to which allocated blocks are released in the order of their allocation for non markovian release processes the extent of the correlation between allocation order and release order varies approximately inversely with the coefficient of variation of the memory residence time distribution the simulations show that allocation efficiency depends strongly on the residence time distribution efficiency decreases as the distributions coefficient of variation increases some practical implications are briefly discussed
CACM	concurrent reading and writing the problem of sharing data among asynchronous process is considered it is assumed that only one process at a time can modify the data but concurrent reading and writing is permitted two general theorems are proved and some algorithms are presented to illustrate their use these include a solution to the general problem in which a read is repeated if it might have obtained an incorrect result and two techniques for transmitting messages between processes these solutions do not assume any synchronizing mechanism other than data which can be written by one process and read by other processes
CACM	the aliasing problem in computer generated shaded images certain defects such as jagged edges and disappearing detail have long been an annoyance in digitally generated shaded images although increasing the resolution or defocusing the display can attenuate them an understanding of these defects leads to more effective methods this paper explains the observed defects in terms of the aliasing phenomenon inherent in sampled signals and discusses prefiltering as a recognized cure a method for evaluating filters is presented the application of prefiltering to hidden surface algorithms is discussed and an implementation of a filtering tiler is shown accompanied by examples of its effectiveness
CACM	use of the lru stack depth distribution for simulation of paging behavior two families of probability distributions were needed for use by a virtual memory simulation model headway between page fault distributions and working set size distributions all members of both families can be derived from the lru stack depth distribution simple expressions for the computation of both kinds of distributions are given finally examples are given of both families of distributions as computed from a published stack depth distribution
CACM	considerations for future programming language standards activities this paper reviews the current state of programming language standards activities with respect to the anomalies which exist between the various published and proposed standards for fortran cobol pl i and basic proposals are made for the inclusion of formalisms within future standards and the extension of the standards to include additional items such as error conditions and documentation
CACM	a fast string searching algorithm an algorithm is presented that searches for the location i of the first occurrence of a character string pat in another string string during the search operation the characters of pat are matched starting with the last character of pat the information gained by starting the match at the end of the pattern often allows the algorithm to proceed in large jumps through the text being searched thus the algorithm has the unusual property that in most cases not all of the first i characters of string are inspected the number of characters actually inspected on the average decreases as a function of the length of pat for a random english pattern of length 5 the algorithm will typically inspect i 4 characters of string before finding a match at i furthermore the algorithm has been implemented so that on the average fewer than i patlen machine instructions are executed these conclusions are supported with empirical evidence and a theoretical analysis of the average behavior of the algorithm the worst case behavior of the algorithm is linear in i patlen assuming the availability of array space for tables linear in patlen plus the size of the alphabet
CACM	sitar an interactive text processing system for small computers corrigendum
CACM	multiprocessor memory organization and memory interference the structure of shared memory in a multiprocessor computer system is examined with particular attention to nonin terleaved memory alternative memory organizations are compared and it is shown that a home memory organization in which each processor is associated with one or more memories in which its address space is concentrated is quite effective in reducing memory in terference home memory organization is shown to be particularly suited to certain specialized computation problems as well as to possess advantages in terms of in terference and reliability for general purpose computation results for in terleaved memory are drawn from previous work and are used for comparison trace driven simulations are used to verify the conclusions of the analysis
CACM	the programmers workbench a machine for software development on almost all software development projects the assumption is made that the program development function will be done on the same machine on which the eventual system will run it is only when this production machine is unavailable or when its programming environment is totally inadequate that alternatives are considered in this paper it is suggested that there are many other situations where it would be advantageous to separate the program development and main tenance function onto a specialized computer which is dedicated to that purpose such a computer is here called a programmers workbench the four basic sections of the paper in troduce the subject outline the general concept discuss areas where such an approach may prove beneficial and describe an operational system utilizing this concept
CACM	game interpretation of the deadlock avoidance problem the deadlock avoidance problem may be defined informally as the determination from some a priori information about the processes resources operating system etc of the safe situations which may be realized without endangering the smooth running of the system when each process specifies its future needs by a flowchart of need defined steps a global approach to the phenomenon and its in terpretation as a game between the operating system and the processes allows formalization of risk and safety concepts the bipartite graph representation of this game may then be used to construct explicitly the set of safe states and to study their properties
CACM	regular right part grammars and their parsers this paper in troduces an alternative to context free grammars called regular right part rrp grammars which resemble pascal syntax diagrams formally rrp grammars have production right parts which are nondeterministic finite state machines fsms and as a special case regular expressions since these can be converted to fsms rrp grammars describe the syntax of programming languages more concisely and more understandably than is possible with cf grammars also in troduced is a class of parsers rrp lr m k parsers which includes the cf lr k parsers and provides the same advantages informally an rrp lr m k parser can determine the right end of each handle by considering at most k symbols to the right of the handle and the left end after the right end has been found by considering at most m symbols to the left of the handle a mechanism for determining the left end is required because there is no bound on the length of the handle
CACM	two level control structure for nondeterministic programming the basic ideas of nondeterministic programming are critically reconsidered to single out a proper attitude and programming style for language allowing direct control of nondeterministic features the proposed attitude aims at retaining the purity of the nondeterministic formulation of search processes on one level the attempt level deferring the coordination of problem solving efforts to another the choice level the feasibility of recognizing these two levels is discussed stressing that the structure to be managed at the choice level is a free of contexts the leaves are computational environments each holding an alternative under inspection while the other nodes are associated with choice poin ts according to the proposed programming style a generative function is associated with each choice poin t which expresses the desired choice strategy the main advantage on this approach is the localization of the search strategies each nonterminal node of the tree keeps track of the state of the computation as it was when the choice poin t was last interrogated holding at the same time the strategy to coordinate the available alternatives examples are given in term of nd lisp an extension of lisp designed and implemented according to these guidelines
CACM	high level data flow analysis in contrast to the predominant use of low level in termediate text high level data flow analysis deals with programs essentially at source level and exploits the control flow information implicit in the parse tree the need for high level flow analysis arises from several aspects of recent work on advanced methods of program certification and optimization this paper proposes a simple general method of high level data flow analysis that allows free use of escape and jump statements avoids large graphs when compiling large programs facilitates updating of data flow information to reflect program changes and derives new global information helpful in solving many familiar global flow analysis problems an illustrative application to live variable analysis is presented many of the graphs involved are constructed and analyzed before any programs are compiled thus avoiding certain costs that low level methods incur repeatedly at compile time
CACM	an interactive computer graphics approach to surface representation an in teractive computer graphics method has been developed for the rapid generation of arbitrary shaped three dimensional surfaces the method is a synthesis of spline theory and algorithms an in teractive means for man machine communication and software for static or dynamic graphics display the basic technique employed is a modified lofting method on which sectional curves are represented by uniform b splines and the surface is in terpolated between sections by cardinal splines among the features of this method are algorithms which enable in teractive modification of the b spline representation of the sectional curves at all stages of the process the spatial information is graphically displayed to the user complex surfaces can be created by the combination of a number of shapes that have been separately generated and automatically joined the system has been successfully in terfaced to a variety of analytical routines for structural medical and graphical applications
CACM	optimal surface reconstruction from planar contours in many scientific and technical endeavors a three dimensional solid must be reconstructed from serial sections either to aid in the comprehension of the objects structure or to facilitate its automatic manipulation and analysis this paper presents a general solution to the problem of constructing a surface over a set of cross sectional contours this surface to be composed of triangular tiles is constructed by separately determining an optimal surface between each pair of consecutive contours determining such a surface is reduced to the problem of finding certain minimum cost cycles in a directed toroidal graph a new fast algorithm for finding such cycles is utilized also developed is a closed form expression in term of the number of contour poin ts for an upper bound on the number of operations required to execute the algorithm an illustrated example which involves the construction of a minimum area surface describing a human head is included
CACM	pagination of b  trees with variable length records a strategy is presented for pagination of b  trees with variable length records if records of each length are uniformly distributed within the file and if a wide distribution of record lengths exists within the file then this strategy results in shallow trees with fast access times the performance of this strategy in an application is presented compared with that of another strategy and analyzed
CACM	some new upper bounds on the generation of prime numbers given an integer n what is the computational complexity of finding all the primes less than n a modified sieve of eratosthenes using doubly linked lists yields an algorithm of o n arithmetic complexity this upper bound is shown to be equivalent to the theoretical lower bound for sieve methods without preprocessing use of preprocessing techniques involving space time and additive multiplicative tradeoffs reduces this upper bound to o n log logn and the bit complexity to o n logn log log logn a storage requirement is described using o n logn log logn bits as well
CACM	hardware estimation of a process primary memory requirements a minor hardware extension to the honeywell 6180 processor is demonstrated to allow the primary memory requirements of a process in multics to be approximated the additional hardware required for this estimate to be computed consists of a program accessible register containing the miss rate of the associative memory used for page table words this primary memory requirement estimate was employed in an experimental version of multics to control the level of multiprogramming in the system and to bill for memory usage the resulting systems tuning parameters display configuration insensitivity and it is conjectured that the system would also track shifts in the referencing characteristics of its workload and keep the system in tune
CACM	an analysis of inline substitution for a structured programming language an optimization technique known as inline substitution is analyzed the optimization consists of replacing a procedure invocation by a modified copy of the procedure body the general problem of using inline substitution to minimize execution time subject to size constrain ts is formulated and an approximate algorithmic solution is proposed the algorithm depends on run time statistics about the program to be optimized preliminary results for the clu structured programming language indicate that in programs with a low degree of recursion over 90 percent of all procedure calls can be eliminated with little increase in the size of compiled code and a small savings in execution time other conclusions based on these results are also presented
CACM	the gre advanced test in computer science this report describes the advanced test in computer science which was recently in troduced in the graduate record examination program the gre program is described in general and the events leading to the establishment of the advanced computer science test are discussed content specifications and their rationale are given a set of sample questions is included
CACM	logic and programming languages logic has been long in terested in whether answers to certain questions are computable in principle since the outcome puts bounds on the possibilities of formalization more recently precise comparisons in the efficiency of decision methods have become available through the developments in complexity theory these however are applications to logic and a big question is whether methods of logic have significance in the other direction for the more applied parts of computability theory programming languages offer an obvious opportunity as their syntactic formalization is well advanced however the semantical theory can hardly be said to be complete though we have many examples we have still to give wide ranging mathematical answers to these queries what is a machine what is a computable process how or how well does a machine simulate a process programs naturally enter in giving descriptions of processes the definition of the precise meaning of a program then requires us to explain what are the objects of computation in a way the statics of the problem and how they are to be transformed the dynamics so far the theories of automata and of nets though most in teresting for dynamics have formalized only a portion of the field and there has been perhaps too much concentration on the finite state and algebraic aspects it would seem that the understanding of higher level program features involves us with infinite objects and forces us to pass through several levels of explanation to go from the conceptual ideas to the final simulation on a real machine these levels can be made mathematically exact if we can find the right abstractions to represent the necessary structures the experience of many independent workers with the method of data types as lattices or partial orderings under an information content ordering and with their continuous mappings has demonstrated the flexibility of this approach in providing definitions and proofs which are clean and without undue dependence on implementations nevertheless much remains to be done in showing how abstract conceptualizations can or cannot be actualized before we can say we have a unified theory
CACM	complexity of computations the framework for research in the theory of complexity of computations is described emphasizing the in terrelation between seemingly diverse problems and methods illustrative examples of practical and theoretical significance are given directions for new research are discussed
CACM	another advantage of keyword notation for parameter communication with subprograms
CACM	comment on computing the k shortest paths in a graph
CACM	production and employment of ph d s in computer science 1976 corrigendum
CACM	an efficient data structure for the simulation event set recently algorithms have been presented for the realization of event scheduling routines suitable for general purpose discrete event simulation systems several exhibited a performance superior to that of commonly used simple linked list algorithms in this paper a new event scheduling algorithm is presented which improves on two aspects of the best of the previously published algorithms first the new algorithms performance is quite insensitive to skewed distributions and second its worst case complexity is o n where n is the number of events in the set furthermore tests conducted to estimate the average complexity showed it to be nearly independent of n
CACM	an experimental evaluation of data type conventions the language in which programs are written can have a substantial effect on the reliability of the resulting programs this paper discusses an experiment that compares the programming reliability of subjects using a statically typed language and a typeless language analysis of the number of errors and the number of runs containing errors shows that at least in one environment the use of a statically typed language can increase programming reliability detailed analysis of the errors made by the subjects in programming solutions to reasonably small problems shows that the subjects had difficulty manipulating the representation of data
CACM	toward a discipline of real time programming programming is divided into three major categories with increasing complexity of reasoning in program validation sequential programming multiprogramming and real time programming by adhering to a strict programming discipline and by using a suitable high level language molded after this discipline the complexity of reasoning about concurrency and execution time constrain ts may be drastically reduced this may be the only practical way to make real time systems analytically verifiable and ultimately reliable a possible discipline is outlined and expressed in terms of the language modula
CACM	abstraction mechanisms in clu clu is a new programming language designed to support the use of abstractions in program construction work in programming methodology has led to the realization that three kinds of abstractions procedural control and especially data abstractions are useful in the programming process of these only the procedural abstraction is supported well by conventional languages through the procedure or subroutine clu provides in addition to procedures novel linguistic mechanisms that support the use of data and control abstractions this paper provides an in troduction to the abstraction mechanisms in clu by means of programming examples the utility of the three kinds of abstractions in program construction is illustrated and it is shown how clu programs may be written to use and implement abstractions the clu library which permits incremental program development with complete type checking performed at compile time is also discussed
CACM	abstraction and verification in alphard defining and specifying iteration and generators the alphard form provides the programmer with a great deal of control over the implementation of abstract data types in this paper the abstraction techniques are extended from simple data representation and function definition to the iteration statement the most important poin t of interaction between data and the control structure of the language itself a means of specializing alphards loops to operate on abstract entities without explicit dependence on the representation of those entities is in troduced specification and verification techniques that allow the properties of the generators for such iterations to be expressed in the form of proof rules are developed results are obtained that for common special cases of these loops are essentially identical to the corresponding constructs in other languages a means of showing that a generator will terminate is also provided
CACM	early experience with mesa the experiences of mesas first users primarily its implementers are discussed and some implications for mesa and similar programming languages are suggested the specific topics addressed are module structure and its use in defining abstractions data structuring facilities in mesa an equivalence algorithm for types and type coercions the benefits of the type system and why it is breached occasionally and the difficulty of making the treatment of variant records safe
CACM	an algol based implementation of snobol 4 patterns
CACM	lucid a nonprocedural language with iteration lucid is a formal system in which programs can be written and proofs of programs carried out the proofs are particularly easy to follow and straightforward to produce because the statements in a lucid program are simply axioms from which the proof proceeds by almost conventional logical reasoning with the help of a few axioms and rules of inference for the special lucid functions as a programming language lucid is unconventional because among other things the order of statements is irrelevant and assignment statements are equations nevertheless lucid programs need not look much different than iterative programs in a conventional structured programming language using assignment and conditional statements and loops
CACM	shifting garbage collection overhead to compile time this paper discusses techniques which enable automatic storage reclamation overhead to be partially shifted to compile time the paper assumes a transaction oriented collection scheme as proposed by deutsch and bobrow the necessary features of which are summarized implementing the described optimizations requires global flow analysis to be performed on the source program it is shown that at compile time certain program actions that affect the reference counts of cells can be deduced this information is used to find actions that cancel when the code is executed and those that can be grouped to achieve improved efficiency
CACM	certification of programs for secure information flow this paper presents a certification mechanism for verifying the secure flow of information through a program because it exploits the properties of a lattice structure among security classes the procedure is sufficiently simple that it can easily be included in the analysis phase of most existing compilers appropriate semantics are presented and proved correct an important application is the confinement problem the mechanism can prove that a program cannot cause supposedly nonconfidential results to depend on confidential input data
CACM	an alternative to event queues for synchronization in monitors in the monitor concept as proposed by brinch hansen and hoare event are used for synchronization this paper describes another synchronizing primitive which is nearly as expressive as the conditional wait but can be implemented more efficiently an implementation of this primitive in terms of p and v operations is given together with a correctness proof two examples are presented the readers and writers problem and the problem of information streams sharing a finite buffer pool
CACM	sitar an interactive text processing system for small computers sitar a low cost in teractive text handling and text analysis system for nontechnical users is in many ways comparable to in teractive bibliographical search and retrieval systems but has several additional features it is implemented on a pdp 11 time sharing computer invoked by a crt with microprogrammed editing functions it uses a simple command language designating a function a file and a search template consisting of the textual string desired and strings delimiting the context in which the hit is to be delivered extensive experience with sitar shows that the combined powers of simple commands string orientation circular file structure a crt with local memory and conversational computing produce a system much more powerful than the sum of its parts
CACM	a terminal oriented communication system this paper describes a system for full duplex communication between a time shared computer and its terminals the system consists of a communications computer directly connected to the time shared system a number of small remote computers to which the terminals are attached and connecting medium speed telephone lines it can service a large number of terminals of various types the overall system design is presented along with the algorithms used to solve three specific problems local echoing error detection and correction on the telephone lines and multiplexing of character output
CACM	a correctness proof of a topology information main tenance protocol for a distributed computer network in order for the nodes of a distributed computer network to communicate each node must have information about the networks topology since nodes and links sometimes crash a scheme is needed to update this information one of the major constrain ts on such a topology information scheme is that it may not involve a central controller the topology information protocol that was implemented on the merit computer network is presented and explained this protocol is quite general and could be implemented on any computer network it is based on barans hot potato heuristic routing doctrine a correctness proof of this topology information protocol is also presented
CACM	a unifying approach to scheduling this paper presents a scheme for classifying scheduling algorithms based on an abstract model of a scheduling system which formalizes the notion of priority various classes of scheduling algorithms are defined and related to existing algorithms a criterion for the implementation efficiency of an algorithm is developed and results in the definition of time invariant algorithms which include most of the commonly implemented ones for time invariant algorithms the dependence of processing rates on priorities is derived the abstract model provides a framework for implementing flexible schedulers in real operating systems the policy driven scheduler of bernstein and sharp is discussed as an example of such an implementation
CACM	dynamic response time prediction for computer networks if the ultimate aim of a computing network is resource sharing then the human component as well as the technical component of networking must be fully investigated to achieve this goal this research is a first step toward assisting the user in participating in the vast store of resources available on a network analytical simulation and statistical performance evaluation tools are employed to investigate the feasibility of a dynamic response time monitor that is capable of providing comparative response time information for users wishing to process various computing applications at some network computing node the research clearly reveals that sufficient system data are currently obtainable at least for the five diverse arpa network systems studied in detail to describe and predict the response time for network time sharing systems as it depends on some measure of system activity or load level
CACM	functions realizable with word parallel logical and twos complement addition instructions
CACM	notes on recursion elimination various methods of recursion elimination are applied to the schematic recursive procedure proc s x px then n x s fx s gx m x fi procedures with this general form arise in connection with tree traversal and sorting algorithms each method of recursion removal involves the use of one or more stacks and the solutions are compared on the basis of their running time
CACM	a bounded storage algorithm for copying cyclic structures a new algorithm is presented which copies cyclic list structures using bounded workspace and linear time unlike a previous similar algorithm this one makes no assumptions about the storage allocation system in use and uses only operations likely to be available in a high level language the distinctive feature of this algorithm is a technique for traversing the structure twice using the same spanning tree in each case first from left to right and then from right to left
CACM	buddy systems two algorithms are presented for implementing any of a class of buddy systems for dynamic storage allocation each buddy system corresponds to a set of recurrence relations which relate the block sizes provided to each other analyses of the in ternal fragmentation of the binary buddy system the fibonacci buddy system and the weighted buddy system are given comparative simulation results are also presented for in ternal external and total fragmentation
CACM	some ideas on data types in high level languages a number of issues are explored concerning the notion that a data type is a set of values together with a set of primitive operations on those values among these are the need for a notation for iterating over the elements of any finite set instead of the more narrow for i 1 to n notation the use of the domain of an array as a data type the need for a simple notation for allowing types of parameters to be themselves parameters but in a restrictive fashion and resulting problems with conversion of values from one type to another
CACM	database abstractions aggregation aggregation is in troduced as an abstraction which is important in conceptualizing the real world aggregation transforms a relationship between objects into a higher level object a new data type called aggregation is developed which under certain criteria of well definedness specifies aggregation abstractions relational databases defined as collections of aggregates are structured as a hierarchy on n ary relations to main tain well definedness update operations on such databases must preserve two invariants well defined relations are distinct from relations in third normal form it is shown that these notions are complementary and both are important in database design a top down methodology for database design is described which separates decisions concerning aggregate structure from decisions concerning key identification it is suggested that aggregate types and other types which support real world abstractions without in troducing implementation detail should be incorporated into programming languages
CACM	abstract data types and the development of data structures abstract data types can play a significant role in the development of software that is reliable efficient and flexible this paper presents and discusses the application of an algebraic technique for the specification of abstract data types among the examples presented is a top down development of a symbol table for a block structured language a discussion of the proof of its correctness is given the paper also contains a brief discussion of the problems involved in constructing algebraic specifications that are both consistent and complete
CACM	the system for business automation sba programming language the system for business automation sba is a system within which application experts nonprogrammers can describe and execute their applications on a computer the user of sba views his application as manipulation of information in two dimensional pictures of tables business forms and reports on a display terminal he can gradually automate this application by giving examples to the system of how he manually manipulates the information the query by example database language is a subset of the sba programming language
CACM	two views of data abstraction
CACM	experimental investigations of the utility of detailed flowcharts in programming this paper describes previous research on flowcharts and a series of controlled experiments to test the utility of detailed flowcharts as an aid to program composition comprehension debugging and modification no statistically significant difference between flowchart and nonflowchart groups has been shown thereby calling into question the utility of detailed flowcharting a program of further research is suggested
CACM	production and employment of ph d s in computer science 1976 statistics are presented on the production and employment of ph d s in computer science for the calendar year 1975 76 data include profiles of graduate students and of faculty at 60 ph d  producing departments as well as a breakdown of degrees granted by specialty areas significant trends are noted and comparisons with comparable data gathered for the 1974 75 calendar year are made
CACM	a fast algorithm for computing longest common subsequences previously published algorithms for finding the longest common subsequence of two sequences of length n have had a best case running time of o n 2 an algorithm for this problem is presented which has a running time of o r n log n where r is the total number of ordered pairs of positions at which the two sequences match thus in the worst case the algorithm has a running time of o n 2 log n however for those applications where most positions of one sequence match relatively few positions in the other sequence a running time of o n log n can be expected
CACM	an approach to optimal design of storage parameters in databases
CACM	an optimal evaluation of boolean expressions in an online query system
CACM	the choice of reference poin ts in best match file searching improvements to the exhaustive search method of best match file searching have previously been achieved by doing a preprocessing step involving the calculation of distances from a reference poin t this paper discusses the proper choice of reference poin ts and extends the previous algorithm to use more than one reference poin t it is shown that reference poin ts should be located outside of data clusters the results of computer simulations are presented which show that large improvements can be achieved by the proper choice and location of multiple reference poin ts
CACM	a comparison of hardware and software associative memories in the context of computer graphics the associative processing of line drawings apld system utilizes a hardware associative memory and creates modifies deletes stores and retrieves two dimensional line drawings consisting of poin ts lines rectangles and triangles the apld functions were duplicated on the tx 2 computer at m i t s lincoln laboratory under the leap language and data structure a comparison of the hardware approach with the software simulation illustrates the advantages of the hardware associative memory in three areas 1 processing speed 2 storage requirements and 3 flexibility the major problem areas of hardware associative memory technology namely input output and cost effectiveness are also addressed
CACM	a comparison of tree balancing algorithms several algorithms height balance i e avl and extensions weight balance i e bb and wb and total restructuring for building balanced binary search trees are compared the criteria for comparison encompass theoretical aspects e g path lengths and implementation independent and machine algorithm dependent measures e g run time a detailed analysis of code is also presented at a level believed to be language and compiler independent the quality of the resulting trees and the overhead spent on building them are analyzed and some guidelines are given for an efficient use of the methods if insertion and subsequent queries are the only operations of in terest then pure avl trees present the overall best qualities
CACM	optimal program and data locations in computer networks an optimization procedure for the allocation of program and data files in a computer network is presented this algorithm takes into account the dependencies between files and programs such as occur in real heterogeneous computer networks insights into whether or not to convert programs from one computer to another can also be gained from the model a search procedure for the file location problem is described along with an example and a possible application of the model
CACM	achieving specific accuracy in simulation output analysis this paper extends the use of the regenerative property of queueing systems in the analysis of simulation output in particular it describes a sequential estimation method which when used with the regenerative property allows results to be obtained with specified statistical accuracy this method includes a test to check the normality assumption on which the sequential procedure relies the paper illustrates the method using the empty and idle state as the regenerative state a second example then describes how using the most frequently entered state as the regenerative state reduces the chance of making a costly error in a preliminary simulation run the paper also described how a variance reduction method due to page 9 can be used to obtain a specified accuracy with considerably fewer job completions than are required when no variance reduction technique is applied
CACM	sp k a system for teaching computer programming sp k is a compatible subset of the pl i language that has been designed for teaching programming the features of the sp k language were chosen to encourage structured problem solving by computers to make the language easy to learn and use to eliminate confusing and redundant constructs and to make the language easy to compile the resulting language is suitable for in troducing programming concepts used in various applications including business data processing scientific calculations and non numeric computation sp k is actually a sequence of language subsets called sp 1 sp 2 sp 8 each subset in troduces new programming language constructs while retaining all the constructs of preceding subsets each subset is precisely defined and can be learned or implemented without the following subsets
CACM	proof techniques for hierarchically structured programs a method for describing and structuring programs that simplifies proofs of their correctness is presented the method formally represents a program in terms of levels of abstraction each level of which can be described by a self contained nonprocedural specification the proofs like the programs are structured by levels although only manual proofs are described in the paper the method is also applicable to semi automatic and automatic proofs preliminary results are encouraging indicating that the method can be applied to large programs such as operating systems
CACM	sorting on a mesh connected parallel computer two algorithms are presented for sorting n 2 elements on an n x n mesh connected processor array that require o n routing and comparison steps the best previous algorithm takes time o n log n the algorithms of this paper are shown to be optimal in time within small constant factors extensions to higher dimensional arrays are also given
CACM	comment on weighted increment linear search for scatter tables
CACM	remark on uniform insertion in structured data structures
CACM	approximating block accesses in database organizations
CACM	the stage hypothesis and the s curve some contradictory evidence this paper presents the results of a study testing the s shaped budget curve of nolans stage model of computer development in an organization research on the data processing budgets of california counties fails to support the s shaped curve or the use of budgets as a basis for a stage model however the results do not invalidate the concept of a stage model the analysis suggests an alternative model of budget growth and a separation between models of budgeting growth and growth stages in the development of the computer resource
CACM	analysis of design alternatives for virtual memory indexes a class of index structures for use in a virtual memory environment is described design alternatives within this class of index structures are analyzed these alternatives include a choice of search strategy whether or not pages in the index are structured and whether or not keys are compressed the average cost of retrieving entries from these indexes is expressed as a wieghted sum of the cost of a basic key comparison and the cost of crossing a page boundary in the index structure formulas for the retrieval costs for possible combinations of design alternatives are given these are used in numerical case studies which compare the retrieval costs of the alternatives qualitative comparisons of the main tenance costs insertion deletion reorganization of the design alternatives are also included
CACM	studies in machine cognition using the game of poker a progress report is presented of on going research efforts concerning human decision making under uncertainly and risk and human problem solving and learning processes on the one hand and machine learning large scale programming systems and novel programming techniques on the other there has also been in terest in how humans make deductive and inductive inferences and form and optimize heuristic rules and how machines can reach similar results although the vehicle of these investigations has been the game of poker a conceptual framework has been provided that should have a fairly wide range of applicability the models of human judgment choice and decision making are incorporated in a large scale complex program they represent both descriptive and normative theories of behavior an in teractive game environment has been recently established which besides its usefulness for experiments in game playing enables humans to construct machine strategies on line in a question answering advice taking mode
CACM	the editing of picture segmentations using local analysis of graphs a major problem in picture processing is the elimination of the large number of spurious regions that result from an initial segmentation by region growing techniques such regions have been eliminated either on the basis of semantic information or on the basis of size and contrast a scheme is presented which performs eliminations on the basis of local properties of the region adjacency graph the scheme is based on definitions of graph properties which are satisfied when a spurious region is present then editing is equivalent to fast graph operations a number of examples are shown
CACM	subgoal induction a proof method subgoal induction is presented as an alternative or supplement to the commonly used inductive assertion method its major virtue is that it can often be used to prove a loops correctness directly from its input output specification without the use of an invariant the relation between subgoal induction and other commonly used induction rules is explored and in particular it is shown that subgoal induction can be viewed as a specialized form of computation induction a set of sufficient conditions are presented which guarantee that an input output specification is strong enough for the induction steps of a proof by subgoal induction to be valid
CACM	the storage requirement in precedence parsing
CACM	a comparison of next fit first fit and best fit
CACM	cost utilization a measure of system performance a method is presented for evaluating computer system performance in terms of a cost utilization factor and a measure of imbalance these coefficients indicate the extent to which the total system cost is effectively utilized the method includes a technique for the visual representation of system performance
CACM	effects of chargeout on user manager attitudes the relationship of in ternal pricing systems for computer services chargeout systems and user management attitudes about their computer based information systems is investigated evidence is provided that the relationship conforms to a general pattern that would be expected from the hypothesis of the four stages of edp growth 15 the results also indicate that the chargeout systems characteristic of advanced edp stage environments are associated with relatively high levels of positive user attitudes and marked increases in edp training for users both factors are important to the user manager involvement necessary for effective control of computer based systems development and main tenance of computer based systems is asserted to be a category of organizational change a felt need for the change on the part of the user manager is prerequisite to any change taking place the research methods of behavioral science are applied to investigate the user manager environment and the effects of chargeout
CACM	operations on sparse relations various computations on relations boolean matrices or directed graphs such as the computation of precedence relations for a context free grammar can be done by a practical algorithm that is asymptotically faster than those in common use for example how to compute operator precedence or wirth weber precedence relations in o n 2 steps is shown as well as how to compute linear precedence functions in o n 2 steps is shown as well as how to compute linear precedence functions in o n steps where n is the size of a grammer the heart of the algorithms is a general theorem giving sufficient conditions under which an expression whose operands are sparse relations and whose operators are composition transitive closure union and inverse can be computed efficiently
CACM	representation of many sided polygons and polygonal lines for rapid processing a representation for polygons and polygonal lines is described which allows sets of consecutive sides to be collectively examined the set of sides are arranged in a binary tree hierarchy by inclusion a fast algorithm for testing the inclusion of a poin t in a many sided polygon is given the speed of the algorithm is discussed for both ideal and practical examples it is shown that the poin ts of intersection of two polygonal lines can be located by what is essentially a binary tree search the algorithm and a practical example are discussed the representation overcomes many of the disadvantages associated with the various fixed grid methods for representing curves and regions
CACM	memory management and response time this paper presents a computationally tractable methodology for including accurately the effects of finite memory size and workload memory requirements in queueing network models of computer systems empirical analyses and analytic studies based on applying this methodology to an actual multiaccess in teractive system are reported relations between workload variables such as memory requirement distribution and job swap time and performance measures such as response time and memory utilization are graphically displayed a multiphase analytically soluble model is proposed as being broadly applicable to the analysis of in teractive computer systems which use nonpaged memories
CACM	empirical evaluation of some features of instruction set processor architectures this paper presents methods for empirical evaluation of features of instruction set processors isps isp features are evaluated in terms of the time used or saved by having or not having the feature the methods are based on analysis of traces of program executions the concept of a register life is in troduced and used to answer questions like how many registers are used simultaneously how many would be sufficient all of the time most of the time what would the overhead be if the number of registers were reduced what are registers used for during their lives the paper also discusses the problem of detecting desirable but non existing instructions other problems are briefly discussed experimental results are presented obtained by analyzing 41 programs running on the dec system 10 isp
CACM	effective information retrieval using term accuracy the performance of information retrieval systems can be evaluated in a number of different ways much of the published evaluation work is based on measuring the retrieval performance of an average user query unfortunately formal proofs are difficult to construct for the average case in the present study retrieval evaluation is based on optimizing the performance of a specific user query the concept of query term accuracy is in troduced as the probability of occurrence of a query term in the documents relevant to that query by relating term accuracy to the frequency of occurrence of the term in the documents of a collection it is possible to give formal proofs of the effectiveness with respect to a given user query of a number of automatic indexing systems that have been used successfully in experimental situations among these are inverse document frequency weighting thesaurus construction and phrase generation
CACM	improving the access time for random access files clustering in the key set is decreased by smoothing the key to address transformation and by adding shadow buckets to an open chaining file the keys are pre hashed before the address division to remove the effect of sequential properties in the key set shadow buckets in the key search sequence reduce the effect of nonuniformity in file loading and decrease the number of maximum probes needed to locate a record the combined effects of these techniques lead to improved file performance for secondary storage devices as shown by empirical studies
CACM	a numbering system for binary trees
CACM	occurrences of cycling and other phenomena arising in a class of linear programming models an investigation into the average queue size for a certain class of queues has resulted in the formulation of linear programming problems which are ill conditioned in some cases in attempting to solve these linear programming models using ibms mps package instances of cycling were encountered small perturbations in the input data resulted in problems which did not cycle this fact plus several other observed phenomena suggest that the primary reason that cycling is not known to occur more frequently is the round off errors in the computations perturb the problem sufficiently to prevent cycling or at least to prevent indefinite cycling in one case maximizing and minimizing an objective function subject to the same constrain t set was attempted but mps solved only one of these while giving an indication of infeasibility for the other
CACM	a linear algorithm for incremental digital display of circular arcs circular arcs can be drawn on an incremental display device such as a cathode ray tube digital plotter or matrix prin ter using only sign testing and elementary addition and subtraction this paper describes methodology for producing dot or step patterns closet to the true circle
CACM	decomposability instabilities and saturation in multiprogramming systems corrigendum
CACM	transient free working set statistics transient free average working set size and transient free missing page rate for a finite sample of a reference string are defined use of these statistics is appropriate if the contents of the working set at the start of the recorded string are unknown if a certain stationarity condition holds these statistics provide unbiased estimates of expected working set sizes missing page probabilities and in terreference distance probabilities two other pairs of estimators are shown to be biased expressions for the transient free statistics are obtained in terms of in terval statistics several methods of computation are discussed the usefulness of each depending on length of the sample number of distinct references and the amount of main storage available to the computer performing the calculations in particular methods are described for handling long strings containing many distinct page names
CACM	convex hulls of finite sets of poin ts in two and three dimensions the convex hulls of sets of n poin ts in two and three dimensions can be determined with o n log n operations the presented algorithms use the divide and conquer technique and recursively apply a merge procedure for two nonin tersecting convex hulls since any convex hull algorithm requires at least o n log n operations the time complexity of the proposed algorithms is optimal within a multiplicative constant
CACM	an empirical study of list structure in lisp static measurements of the list structure of five large lisp programs are reported and analyzed in this paper these measurements reveal substantial regularity or predictability among poin ters to atoms and especially among poin ters to lists pointers to atoms are found to obey roughly zipfs law which governs word frequencies in natural languages poin ters to lists usually poin t to a location physically nearby in memory the use of such regularities in the space efficient representation of list structure is discussed linearization of lists whereby successive cdrs or cars are placed in consecutive memory locations whenever possible greatly strengthens the observed regularity of list structure it is shown that under some reasonable assumptions the entropy or information content of a car cdr pair in the programs measured is about 10 to 15 bits before linearization and about 7 to 12 bits after
CACM	an approach to multidimensional data array processing by computer some recent work on the development of general purpose computer based statistical and data processing capabilities for handling multidimensional arrays of data is presented attention is first given to some of the general problems of multidimensional table and array processing this is followed by a summary of some recent developments in array processing capabilities at the world bank in particular the system identified as wraps world bank retrieval and array processing system
CACM	segment sizes and lifetimes in algol 60 programs the characteristics of the virtual memory requirements of a sample of algol 60 programs have been measured distributions are presented for thesizes of memory requests and for their holding times lifetimes the results are presented in terms of johnstons contour model and a simple abstract machine they provide new empirical evidence of certain aspects of the construction and behavior of real programs and some of their implications for the design of virtual memory systems are presented and discussed
CACM	detection of combined occurrences in this paper it is supposed that the variables x1 xn each have finite range with the variable xi taking on pi possible values and that the values of the variables are changing with time it is supposed further that it is desired to detect occurrences in which some subset of the variables achieve particular values finally it is supposed that the problem involves the detection of a large number of combined occurrences for a large number of changes of values of variables two efficient solutions for this problem are described both methods have the unusual property of being faster for systems where the sum p1 pn is larger the first solution is error free and suitable for most cases the second solution is slightly more elegant and allows negation as well as conjunction but is subject to the possibility of errors an error analysis is given for the second method and an empirical study is reported
CACM	a record and file partitioning model one of the main objectives in the design of a file system is the reduction of storage and data transfer costs this paper presents a model in which several requests access the file system and each request requires information from one or more variable length data items the probabilities of access and the distribution of each data items length are assumed to be known and to be mutually independent the file system uses one or more storage devices and each record may be partitioned into subrecords that are stored on different devices one of the subrecords is designated as the primary record when a request for a record is made the primary record is first accessed and other subrecords are accessed only if the pertinent information is not stored in the primary record the model that is presented in this paper both as a nonlinear programming model and a mixed integer programming model is a very general one several types of file systems may be derived from it by an appropriate selection of its parameters this model has already been used in the optimization of library routines storage at a large scale operating system
CACM	a survey of the literature in computer science education since curriculum 68 a bibliography of approximately two hundred references in computer science education appearing in the literature since the publication of curriculum 68 is presented the bibliography itself is preceded by brief descriptive materials organizing the references into the categories of survey reports activities of professional organizations philosophy of programs description of programs description of courses and other materials
CACM	structured programming in cobol an approach for application programmers techniques for designing and writing cobol programs are presented previous work in structured programming is drawn upon and adapted the presentation is informal the terminology is nonmathematical as far as possible no theorems are proved and examples are used frequently top down program design is implemented through the use of structured flowcharts disciplined specifications and step by step verification a well formed cobol program is defined the proper use of the go to and other cobol coding practices are discussed
CACM	implications of structured programming for machine architecture based on an empirical study of more than 10 000 lines of program text written in a goto less language a machine architecture specifically designed for structured programs is proposed since assignment call return and if statements together account for 93 percent of all executable statements special care is given to ensure that these statements can be implemented efficiently a highly compact instruction encoding scheme is presented which can reduce program size by a factor of 3 unlike a huffman code which utilizes variable length fields this method uses only fixed length 1 byte op code and address fields the most frequent instructions consist of a single 1 byte field as a consequence instruction decoding time is minimized and the machine is efficient with respect to both space and time
CACM	anomalies with variable partition paging algorithms five types of anomalous behavior which may occur in paged virtual memory operating systems a redefined one type of anomaly for example concerns the fact that with certain reference strings and paging algorithms an increase in mean memory allocation may result in an increase in fault rate two paging algorithms are examined in terms of their anomaly potential and reference string examples of various anomalies are presented two paging algorithm properties the inclusion property and the generalized inclusion property are discussed and the anomaly implications of these properties presented
CACM	complexity of computations corrigendum
CACM	preserving average proximity in arrays programmers and data structure designers are often forced to choose between alternative structures in storing these structures preserving logical adjacencies or proximity is usually an important consideration the combinatorial problem of storing arrays as various kinds of list structures is examined embeddings of graphs are used to model the loss of proximity involved in such storage schemes and an elementary proof that arrays cannot be stored as linear lists with bounded loss of proximity is presented average loss of proximity is then considered and it is shown that arrays cannot be stored as linear lists with only bounded loss of average proximity but can be so stored in binary trees the former result implies for instance that row major order is an asymptotically optimal storage strategy for arrays
CACM	insertions and deletions in one sided height balanced trees recently hirschberg has established that insertions into one sided height balanced trees can be done in 0 log 2n steps it is proved here that deletions can also be performed in 0 log 2n steps which answers the open problem posed by hirschberg
CACM	value orientation of computer science students technological and nontechnological value orientations are investigated with special attention to the complexity of value structures computer science students who are closely associated with technology contrast with social science students who are often technologically aloof this is confirmed by the value ratings of 313 students at the university of minnesota in 1972 computer science majors were found to have a more complex value structure than social science majors
CACM	management utilization of computers in american local governments traditional concepts of management information systems mis bear little relation to the information systems currently in use by top management in most us local governments what exists is management oriented computing involving the use of relatively unsophisticated applications despite the unsophisticated nature of these systems management use of computing is surprisingly common but also varied in its extent among local governments management computing is most prevalent in those governments with professional management practices where top management is supportive of computing and tends to control computing decisions and where department users have less control over design and implementation activities finally management computing clearly has impacts for top managers mostly involving improvements in decision information
CACM	the use of an interactive information storage and retrieval system in medical research this paper presents the results of a study of the use of an interactive computerized storage and retrieval system a monitor built into the computer system provided usage data for the study additional data on user reactions were gathe red from a questionnaire the results show the important role played by frequently chosen laboratory reference leaders in influencing the use of this system the implications of the study for the design of similar systems are discussed
CACM	some new methods of detecting step edges in digital pictures this note describes two operators that respond to step edges but not to ramps the first is similar to the digital laplacian but uses the max rather than the sum of the x and y second differences the second uses the difference between the mean and median gray levels in a neighborhood the outputs obtained from these operators applied to a set of test pictures are compared with each other and with the standard digital laplacian and gradient a third operator which uses the distance between the center and centroid of a neighborhood as an edge value is also briefly considered it turns out to be equivalent to one of the standard digital approximations to the gradient
CACM	is sometime sometimes better than always intermittent assertions in proving program correctness this paper explores a technique for proving the correctness and termination of programs simultaneously this approach the intermittent assertion method involves documenting the program with assertions that must be true at some time when control passes through the corresponding point but that need not be true every time the method introduced by burstall promises to provide a valuable complement to the more conventional methods the intermittent assertion method is presented with a number of examples of correctness and termination proofs some of these proofs are markedly simpler than their conventional counterparts on the other hand it is shown that a proof of correctness or termination by any of the conventional techniques can be rephrased directly as a proof using intermittent assertions finally it is shown how the intermittent assertion method can be applied to prove the validity of program transformations and the correctness of continuously operating programs
CACM	relaxation methods for image reconstruction the problem of recovering an image a function of two variables from experimentally available integrals of its grayness over thin strips is of great importance in a large number of scientific areas an important version of the problem in medicine is that of obtaining the exact density distribution within the human body from x ray projections one approach that has been taken to solve this problem consists of translating the available information into a system of linear inequalities the size and the sparsity of the resulting system typically 25 000 inequalities with fewer than 1 percent of the coefficients nonzero makes methods using successive relaxations computationally attractive as compared to other ways of solving systems of inequalities in this paper it is shown that for a consistent system of linear inequalities any sequence of relaxarion parameters lying strictly between 0 and 2 generates a sequence of vectors which converges to a solution under the same assumptions for a system of linear equations the relaxation method converges to the minimum norm solution previously proposed techniques are shown to be special cases of our procedure with different choices of relaxation parameters the practical consequences for image reconstruction of the choice of the relaxation parameters are discussed
CACM	a comparison of numerical techniques in markov modeling this paper presents several numerical methods which may be used to obtain the stationary probability vectors of markovian models an example of a nearly decomposable system is considered and the results obtained by the different methods examined a post mortem reveals why standard techniques often fail to yield the correct results finally a means of estimating the error inherent in the decomposition of certain models is presented
CACM	b trees re examined the b tree and its variants have with increasing frequency been proposed as a basic storage structure for multiuser database applications here three potential problems which must be dealt with in such a structure that do not arise in more traditional static directory structures are indicated one problem is a possible performance penalty
CACM	covering edges by cliques with regard to keyword conflicts and intersection graphs kellerman has presented a method for determining keyword conflicts and described a heuristic algorithm which solves a certain combinatorial optimization problem in connection with this method this optimization problem is here shown to be equivalent to the problem of covering the edges of a graph by complete subgraphs with the objective of minimizing the number of complete subgraphs a relationship between this edge clique cover problem and the graph coloring problem is established which allows algorithms for either one of these problems to be constructed from algorithm for the other as consequences of this relationship the keyword conflict problem and the edge clique cover problem are shown to be np complete and if p np then they do not admit polynomial time approximation algorithms which always produce solutions within a factor less than 2 from the optimum
CACM	the gre advanced test in computer science
CACM	systematic recursion removal the recursion removal algorithm presented by strong and walker is amplified and applied to a relatively complex pl i program the aim is to demonstrate systematic recursion removal techniques on something more complex than knuths sturdy toddler and to obtain measurements of the cost of procedure linkage in pl i and the savings achievable via procedure integration in the presence of recursion first the paper describes the recursion removal process and the example on which it will be illustrated recursion removal is then applied to the two major parts of this example and the final result of the process is displayed our performance comparison results are presented and our conclusions are briefly discussed
CACM	a method for obtaining digital signatures and public key cryptosystems an encryption method is presented with the novel property that publicly revealing an encryption key does not thereby reveal the corresponding decryption key this has two important consequences 1 couriers or other secure means are not needed to transmit keys since a message can be enciphered using an encryption key publicly revealed by the intended recipient only he can decipher the message since only he knows the corresponding decryption key 2 a message can be signed using a privately held decryption key anyone can verify this signature using the corresponding publicly revealed encryption key signatures cannot be forged and a signer cannot later deny the validity of his signature this has obvious applications in electronic mail and electronic funds transfer systems a message is encrypted by representing it as a number m raising m to a publicly specified power e and then taking the remainder when the result is divided by the publicly specified product n of two large secret prime numbers p and q decryption is similar only a different secret power d is used where e d 1 mod p 1 q 1 the security of the system rests in part on the difficulty of factoring the published divisor n
CACM	computer science faculties the current status of minorities and women the results of a survey conducted in the fall of 1975 to determine the status of women and minority faculty members in academic computer science are presented faculty members were compared with respect to professional background salaries teaching load publication records and research grants analysis of the data indicated that the over all verdict is one of general equality among women minorities and men
CACM	architecture of the ibm system 370 this paper discusses the design considerations for the architectural extensions that distinguish system 370 from system 360 it comments on some experiences with the original objectives for system 360 and on the efforts to achieve them and it describes the reasons and objectives for extending the architecture it covers virtual storage program control data manipulation instructions timing facilities multiprocessing debugging and monitoring error handling and input output operations a final section tabulates some of the important parameters of the various ibm machines which implement the architecture
CACM	the cray 1 computer system this paper describes the cray 1 discusses the evolution of its architecture and gives an account of some of the problems that were overcome during its manufacture the cray 1 is the only computer to have been built to date that satisfies erdas class vi requirement a computer capable of processing from 20 to 60 million floating point operations per second 1 the cray 1s fortran compiler cft is designed to give the scientific user immediate access to the benefits of the cray 1s vector processing architecture an optimizing compiler cft vectorizes innermost do loops compatible with the ansi 1966 fortran standard and with many commonly supported fortran extensions cft does not require any source program modifications or the use of additional nonstandard fortran statements to achieve vectorization thus the users investment of hundreds of man months of effort to develop fortran programs for other contemporary computers is protected
CACM	the evolution of the dec system 10 the dec system 10 also known as the pdp 10 evolved from the pdp 6 circa 1963 over five generations of implementations to presently include systems covering a price range of five to one the origin and evolution of the hardware operating system and languages are described in terms of technological change user requirements and user developments the pdp 10s contributions to computing technology include accelerating the transition from batch oriented to time sharing computing systems transferring hardware technology within dec and elsewhere to minicomputer design and manufacturing supporting minicomputer hardware and software development and serving as a model for single user and timeshared interactive minicomputer microcomputer systems
CACM	the evolution of the sperry univac 1100 series a his tory analysis and projection the 1100 series systems are sperry univacs large scale main frame computer systems beginning with the 1107 in 1962 the 1100 series has progressed through a succession of eight compatible computer models to the latest system the 1100 80 introduced in 1977 the 1100 series hardware architecture is based on a 36 bit word ones complement structure which obtains one operand from storage and one from a high speed register or two operands from high speed registers the 1100 operating system is designed to support a symmetrical multiprocessor configuration simultaneously providing multiprogrammed batch timesharing and transaction environments
CACM	the development of the mu5 computer system following a brief outline of the background of the mu5 project the aims and ideas for mu5 are discussed a description is then given of the instruction set which includes a number of features conducive to the production of efficient compiled code from high level language source programs the design of the processor is then traced from the initial ideas for an associatively addressed name store to the final multistage pipeline structure involving a prediction mechanism for instruction prefetching and a function queue for array element accessing an overall view of the complete mu5 complex is presented together with a brief indication of its performance
CACM	the manchester mark i and atlas a his torical perspective in 30 years of computer design at manchester university two systems stand out the mark i developed over the period 1946 49 and the atlas 1955 62 this paper places each computer in its his torical context and then describes the architecture and system software in present day terminology several design concepts such as address generation and store management have evolved in the progression from mark i to atlas the wider impact of manchester innovations in these and other areas is discussed and the contemporary performance of the mark i and atlas is evaluated
CACM	foreword to the special issue on computer architecture
CACM	an example of hierarchical design and proof hierarchical programming is being increasingly recognized as helpful in the construction of large programs users of hierarchical techniques claim or predict substantial increases in productivity and in the reliability of the programs produced in this paper we describe a formal method for hierarchical program specification implementation and proof we apply this method to a significant list processing problem and also discuss a number of extensions to current programming languages that ease hierarchical program design and proof
CACM	abstract data types and software validation a data abstraction can be naturally specified using algebraic axioms the virtue of these axioms is that they permit a representation independent formal specification of a data type an example is given which shows how to employ algebraic axioms at successive levels of implementation the major thrust of the paper is twofold first it is shown how the use of algebraic axiomatizations can simplify the process of proving the correctness of an implementation of an abstract data type second semi automatic tools are described which can be used both to automate such proofs of correctness and to derive an immediate implementation from the axioms this implementation allows for limited testing of programs at design time before a conventional implementation is accomplished
CACM	reverse path forwarding of broadcast packets a broadcast packet is for delivery to all nodes of a network algorithms for accomplishing this delivery through a store and forward packet switching computer network include 1 transmission of separately addressed packets 2 multidestination addressing 3 hot potato forwarding 4 spanning tree forwarding and 5 source based forwarding to this list of algorithms we add 6 reverse path forwarding a broadcast routing method which exploits routing procedures and data structures already available for packet switching reverse path forwarding is a practical algorithm for broadcast routing in store and forward packet switching computer networks the algorithm is described as being practical because it is not optimal according to metrics developed for its analysis in this paper and also because it can be implemented in existing networks with less complexity than that required for the known alternatives
CACM	optimizing decision trees through heuristically guided search optimal decision table conversion has been tackled in the literature using two approaches dynamic programming and branch and bound the former technique is quite effective but its time and space requirements are independent of how easy the given table is furthermore it cannot be used to produce good quasi optimal solutions the branch and bound technique uses a good heuristic to direct the search but is cluttered up by an enormous search space since the number of solutions increases with the number of test variables according to a double exponential in this paper we suggest a heuristically guided top down search algorithm which like dynamic programming recognizes identical subproblems but which can be used to find both optimal and quasi optimal solutions the heuristic search method introduced in this paper combines the positive aspects of the above two techniques compressed tables with a large number of variables can be handled without deriving expanded tables first
CACM	detection of logical errors in decision table programs in this paper an algorithm to detect logical errors in a limited entry decision table and in loop free programs with embedded decision tables is developed all the conditions in the decision tables are assumed to be inequalities or equalities relating linear expressions it is also assumed that actions in a decision table are linear in variables which occur in the condition stub of the decision table or tables to which control is transferred from the table the algorithm is based on determining whether a set of linear inequalities has or does not have a solution the algorithm described in the paper is implemented in fortran iv
CACM	a strategic planning methodology for the computing effort in higher education an empirical evaluation the findings of a study designed to address the pressing problems associated with the strategic planning of the computing effort in higher education are presented here a planning methodology was developed and tested through implementation at a university two years after the methodology was implemented the effectiveness of the planning methodology was assessed in terms of the improvement of the delivery of computing services to the major institutional roles of instruction research and administration two control institutions were employed to contrast the improvements at the test institution the results of the research indicate the planning methodology significantly enhanced the delivery of computing services
CACM	the selection of optimal tab settings a new generation of computer terminals allows tab settings to be selected and set by the computer this feature can be used to reduce the number of characters that are needed to represent a document for transmission and printing in this note an algorithm is given for selecting the optimal set of tab stops for minimizing the number of characters transmitted an implementation of the algorithm has reduced the number of characters transmitted by from 7 to 30 percent but requires a prepass through the document to compute a matrix used in determining the optimal set tab stops the use of fixed tab stops as a heuristic alternative can achieve about 80 percent of optimal with no prepass
CACM	a linear sieve algorithm for finding prime numbers a new algorithm is presented for finding all primes between 2 and n the algorithm executes in time proportional to n assuming that multiplication of integers not larger than n can be performed in unit time the method has the same arithmetic complexity as the algorithm presented by mairson 6 however our version is perhaps simpler and more elegant it is also easily extended to find the prime factorization of all integers between 2 and n in time proportional to n
CACM	using encryption for authentication in large networks of computers use of encryption to achieve authenticated communication in computer networks is discussed example protocols are presented for the establishment of authenticated connections for the management of authenticated mail and for signature verification and document integrity guarantee both conventional and public key encryption algorithms are considered as the basis for protocols
CACM	on the fly garbage collection an exercise in cooperation as an example of cooperation between sequential processes with very little mutual interference despite frequent manipulations of a large shared data space a technique is developed which allows nearly all of the activity needed for garbage detection and collection to be performed by an additional processor operating con currently with the processor devoted to the computation proper exclusion and synchronization constraints have been kept as weak as could be achieved the severe complexities engendered by doing so are illustrated
CACM	synthesizing constraint expressions a constraint network representation is presented for a combinatorial search problem finding values for a set of variables subject to a set of constraints a theory of consistency levels in such networks is formulated which is related to problems of backtrack tree search efficiency an algorithm is developed that can achieve any level of consistency desired in order to preprocess the problem for subsequent backtrack search or to function as an alternative to backtrack search by explicitly determining all solutions
CACM	median split trees a fast lookup technique for frequently occuring keys split trees are a new technique for searching sets of keys with highly skewed frequency distributions a split tree is a binary search tree each node of which contains two key values a node value which is a maximally frequent key in that subtree and a split value which partitions the remaining keys with respect to their lexical ordering between the left and right subtrees a median split tree mst uses the lexical median of a nodes descendents as its split value to force the search tree to be perfectly balanced achieving both a space efficient representation of the tree and high search speed unlike frequency ordered binary search trees the cost of a successful search of an mst is log n bounded and very stable around minimal values further an mst can be built for a given key ordering and set of frequencies in time n log n as opposed to n2 for an optimum binary search tree a discussion of the application of msts to dictionary lookup for english is presented and the performance obtained is contrasted with that of other techniques
CACM	power trees the new class of pk trees is presented where height balance is maintained for the nodes iying on particular paths the number of nodes of a pk tree asymptotically grows as a power of the height in the worst case a procedure for node insertion is given and the class of trees considered is restricted to ipk trees which are buildable by such a procedure the average behavior of such trees studied by an extensive set of simulation runs is close to that of avl trees in particular the family of ipo trees whose main advantage is the reduced number of restructurings required after node insertion is analyzed
CACM	distributed processes a concurrent programming concept a language concept for concurrent processes without common variables is introduced these processes communicate and synchronize by means of procedure calls and guarded regions this concept is proposed for real time applications controlled by microcomputer networks with distributed storage the paper gives several examples of distributed processes and shows that they include procedures coroutines classes monitors processes semaphores buffers path expressions and input output as special cases
CACM	a note on conditional expressions evaluation of a conditional expression may succeed even when the deciding predicate diverges and the alternatives are records or nodes whose fields have different content
CACM	a simple recovery only procedure for simple precedence parsers a simple method is described enabling simple precedence parsers to recover from syntax errors no attempt to repair errors is made yet parsing and most semantic processing can continue the result is a good first approximation to syntax error handling with negligible increase in parsing time space and complexity of both the parser and its table generator
CACM	computer generation of gamma random variables   ii a rejection method is proposed for generating gamma variates with nonintegral shape parameter a a 1 this method is similar to other methods given by fishman wallace and tadikamalla and is faster than these methods for a 2 the core storage requirements and the programming effort for the proposed method are similar to those of wallaces or tadikamallas methods the computational times for the proposed method remain fairly constant for medium and large values of a and are superior to times obtained by ahrens and dieters method for all values of a the proposed method is simpler than ahrens and dieters method
CACM	using synthetic images to register real images with surface models a number of image analysis tasks can benefit from registration of the image with a model of the surface being imaged automatic navigation using visible light or radar images requires exact alignment of such images with digital terrain models in addition automatic classification of terrain using satellite imagery requires such alignment to deal correctly with the effects of varying sun angle and surface slope even inspection techniques for certain industrial parts may be improved by this means we achieve the required alignment by matching the real image with a synthetic image obtained from a surface model and known positions of the light sources the synthetic image intensity is calculated using the reflectance map a convenient way of describing surface reflection as a function of surface gradient we illustrate the technique using landsat images and digital terrain models
CACM	performance evaluation of highly concurrent computers by deterministic simulation simulation is presented as a practical technique for performance evaluation of alternative configurations of highly concurrent computers a technique is described for constructing a detailed deterministic simulation model of a system in the model a control stream replaces the instruction and data streams of the real system simulation of the system model yields the timing and resource usage statistics needed for performance evaluation without the necessity of emulating the system as a case study the implementation of a simulator of a model of the cpu memory subsystem of the ibm 360 91 is described the results of evaluating some alternative system designs are discussed the experiments reveal that for the case study the major bottlenecks in the system are the memory unit and the fixed point unit further it appears that many of the sophisticated pipelining and buffering technique simplemented in the architecture of the ibm 360 91 are of little value when high speed cache memory is used as in the ibm 360 195
CACM	a simply extended and modified batch environment graphical system sembegs sembegs is a complete batch environment graphical system containing components for handling graphical data files for displaying the contents of these files on a variety of graphical hardware and for performing graphical batch input operations sembegs is easy to extend and modify to meet the growing needs of a large batch environment and is even extendable to a fully interactive system the paper presents the conceptual view of graphics leading to the design of sembegs and outlines the major components of the system the design of sembegs is founded upon the basic assumption that the true aim of computer graphics is to describe graphical entities rather than as commonly held to provide graphical input and output functional capabilities sembegs is built around a basic graphical data management system bagdams which provides a common means of communicating the descriptions of graphical entities between the various components of sembegs bagdams provides facilities for storing retrieving and manipulating the descriptions of graphical entities provided by and received by application programs graphics packages and graphical devices
CACM	systems design education a gaming approach one of the problems facing managers of computer installations is the problem of configuring the computer system to meet the demands made by the mix of jobs that the computer center must service this paper presents a management game that allows the player to configure a computer system to meet a hypothetical job mix is under the control of a game administrator and can be varied to simulate a variety of real world situations i o bound jobs compute bound jobs etc the player of the game receives a set of detailed reports on the cost of his choices and a simulated run of the center operating under his choices
CACM	a comparison of heaps and the tl structure for the simulation event set none
CACM	cold start vs warm start miss ratios in a two level computer storage hierarchy miss ratio measurements are often made from a cold start that is made with the first level store initially empty for large capacities the effect on the measured miss ratio of the misses incurred while filling the first level store can be significant even for long reference strings use of warm start rather than cold start miss ratios cast doubt on the widespread belief that the observed s shape of lifetime reciprocal of miss ratio versus capacity curve indicates a property of behavior of programs that maintain a constant number of pages in main storage on the other hand if cold start miss ratios are measured as a function of capacity and measurement length then they are useful in studying systems in which operation of a program is periodically interrupted by task switches it is shown how to obtain under simple assumptions the cache miss ratio for multiprogramming from cold start miss ratio values and how to obtain approximate cold start miss ratios from warm start miss ratios
CACM	packed scatter tables scatter tables for open addressing benefit from recursive entry displacements cutoffs for unsuccessful searches and auxiliary cost functions compared with conventional methods the new techniques provide substantially improved tables that resemble exact solution optimal packings the displacements are depth limited approximations to an enumerative exhaustive optimization although packing costs remain linear o n  with table size n the techniques are primarily suited for important fixed but possibly quite large tables for which reference frequencies may be known op code tables spelling dictionaries access arrays introduction of frequency weights further improves retrievals but the enhancement may degrade cutoffs
CACM	implementing quicksort programs this paper is a practical study of how to implement the quicksort sorting algorithm and its best variants on real computers including how to apply various code optimization techniques a detailed implementation combining the most effective improvements to quicksort is given along with a discussion of how to implement it in assembly language analytic results describing the performance of the programs are summarized a variety of special situations are considered from a practical standpoint to illustrate quicksorts wide applicability as an internal sorting method which requires negligible extra storage
CACM	an analysis of algorithms for the dutch national flag problem solutions to the dutch national flag problem have been given by dijkstra 1 and meyer 3 dijkstra starts with a simple program and arrives at an improved program by refinement both of the algorithms given by dijkstra are shown to have an expected number of swaps which is 2 3n 0 1 and that these values differ at most by 1 3 of a swap and asymptotically by 1 4 of a swap the algorithm of meyer is shown to have expected swap complexity 5 9n
CACM	counting large numbers of events in small registers it is possible to use a small counter to keep approximate counts of large numbers the resulting expected error can be rather precisely controlled an example is given in which 8 bit counters bytes are used to keep track of as many as 130 000 events with a relative error which is substantially independent of the number n of events this relative error can be expected to be 24 percent or less 95 percent of the time i e o n 8 the techniques could be used to advantage in multichannel counting hardware or software used for the monitoring of experiments or processes
CACM	optimal his togram matching by monotone gray level transformation this paper investigates the problem of optimal his togram matching using monotone gray level transformation which always assigns all picture points of a given gray level i to another gray level t i such that if i j then t i t j the objective is to find a transformed digital picture of a given picture such that the sum of absolute errors between the gray level his togram of the transformed picture and that of a reference picture is minimized this is equivalent to placing k1 linearly ordered objects of different sized one by one into k2 linearly ordered boxes of assorted sizes such that the accumulated error of space under packed or overpacked in the boxes is minimized the placement function is monotonic which ensures a polynomial time solution to this problem a tree search algorithm for optimal his togram matching is presented which has time complexity o k1 x k2 if the monotone property is dropped then the problem becomes np complete even if it is restricted to k2 2
CACM	jump searching a fast sequential search technique when sequential file structures must be used and binary searching is not feasible jump searching becomes an appealing alternative this paper explores variants of the classic jump searching scheme where the optimum jump size is the square root of the number of records multiple level and variable size jump strategies are explored appropriate applications are discussed and performance is evaluated
CACM	models for parallel processing within programs application to cpu i o and i o i o overlap approximate queueing models for internal parallel processing by individual programs in a multiprogrammed system are developed in this paper the solution technique is developed by network decomposition the models are formulated in terms of cpu i o and i o i o overlap and applied to the analysis of these problems the percentage performance improvement from cpu i o overlap is found to be greatest for systems which are in approximate cpu i o utilization balance and for low degrees of multiprogramming the percentage improvement from i o i o overlap is found to be greatest for systemtems in which the i o system is more utilized than the cpu
CACM	fortran 77 there is a new standard fortran the official title is american national standard programming language fortran x3 9 1978 but it is more commonly referred to as fortran 77 since its development was completed in 1977 it replaces the fortran standard designated x3 9 1966 this paper describes many of the features of fortran 77 and also provides some information about how and why the standard was developed
CACM	simulations of dynamic sequential search algorithms none
CACM	real time plotting of approximate contour maps none
CACM	a note on virtual memory indexes none
CACM	event manipulation for discrete simulations requiring large numbers of events the event manipulation system presented here consists of two major parts the first part addresses the familiar problem of event scheduling efficiency when the number of scheduled events grows large the second part deals with the less apparent problem of providing efficiency and flexibility as scheduled events are accessed to be executed additional features and problems dealt with include the proper handling of simultaneous events that certain events must be created scheduled and executed at the same points in simulated time that infinite loops caused by the concatenation of such zero time events are possible and must be diagnosed that maintaining various event counts is practical and economical and that a capability for handling time displaceable events is desirable and possible
CACM	right brother trees insertion and deletion are provided for the class of right or one sided brother trees which have o log n performance the importance of these results stems from the close relationship of right brother trees which have an insertion algorithm operating in o log2 n further although both insertion and deletion can be carried out in o log n time for right brother trees it appears that the insertion algorithm is inherently much more difficult than the deletion algorithm the reverse of what one usually obtains
CACM	a controlled experiment in program testing and code walkthroughs inspections this paper describes an experiment in program testing employing 59 highly experienced data processing professionals using seven methods to test a small pl i program the results show that the popular code walk through inspection method was as effective as other computer based methods in finding errors and that the most effective methods in terms of errors found and cost employed pairs of subjects who tested the program independently and then pooled their findings the study also shows that there is a tremendous amount of variability among subjects and that the ability to detect certain types of errors varies from method to method
CACM	generalized working sets for segment reference strings the working set concept is extended for programs that reference segments of different sizes the generalized working set policy gws keeps as its resident set those segments whose retention costs do not exceed their retrieval costs the gws is a model for the entire class of demand fetching memory policies that satisfy a resident set inclusion property a generalized optimal policy gopt is also defined at its operating points it minimizes aggregated retention and swapping costs special cases of the cost structure allow gws and gopt to simulate any known stack algorithm the working set and vmin efficient procedures for computing demand curves showing swapping load as a function of memory usage are developed for gws and gopt policies empirical data from an actual system are included
CACM	a model for verification of data security in operating systems program verification applied to kernel architectures forms a promising method for providing uncircumventably secure shared computer systems a precise definition of data security is developed here in terms of a general model for operating systems this model is suitable as a basis for verifying many of those properties of an operating system which are necessary to assure reliable enforcement of security the application of this approach to the ucla secure operating system is also discussed
CACM	a practical interprocedural data flow analysis algorithm a new interprocedural data flow analysis algorithm is presented and analyzed the algorithm associates with each procedure in a program information about which variables may be modified which may be used and which are possibly preserved by a call on the procedure and all of its subcalls the algorithm is sufficiently powerful to be used on recursive programs and to deal with the sharing of variables which arises through reference parameters the algorithm is unique in that it can compute all of this information in a single pass not requiring a prepass to compute calling relationships or sharing patterns the algorithm is asymptotically optimal in time complexity it has been implemented and is practical even on programs which are quite large
CACM	hybrid simulation models of computer systems this paper describes the structure and operation of a hybrid simulation model in which both discrete event simulation and analytic techniques are combined to produce efficient yet accurate system models in an example based on a simple hypothetical computer system discrete event simulation is used to model the arrival and activation of jobs and a central server queueing network models the use of system processors the accuracy and efficiency of the hybrid technique are demonstrated by comparing the result and computational costs of the hybrid model of the example with those of an equivalent simulation only model
CACM	an algorithm using symbolic techniques for the bel petrov classification of gravitational fields in this note an algorithm is presented for the symbolic calculation of certain algebraic invariants of the weyl tensor which permits the determination of the bel petrov types of a gravitational field this algorithm although more specialized than that of dinverno and russell clark requires neither the use of a special coordinate system nor the spin coefficient formalism the algorithm has been implemented in formac and is designed to complete the classification scheme proposed by petrov in his book an appendix contains examples illustrating the use of the algorithm
CACM	feedback coupled resource allocation policies in the multiprogramming  multiprocessor computer system model studies of some integrated feedback driven scheduling systems for multiprogrammed  multiprocessor computer systems are presented the basic control variables used are the data flow rates for the processes executing on the cpu the model systems feature simulated continuous flow and preempt resume scheduling of input output activity attention is given to the amount of memory resource required for effective processing of the i o activity buffer space assignment the model studies used both distribution driven and trace driven techniques even relatively simple dynamic schedulers are shown to improve system performance as measured by user cpu time over that given by optimal or near optimal static schedulers imbeded in identical system structures and workload environments the improvement is greatest under a heavy i o demand workload
CACM	communicating sequential processes this paper suggests that input and output are basic primitives of programming and that parallel composition of communicating sequential processes is a fundamental program structuring method when combined with a development of dijkstras guarded command these concepts are surprisingly versatile their use is illustrated by sample solutions of a variety of familiar programming exercises
CACM	a time  and space  efficient garbage compaction algorithm given an area of storage containing scattered marked nodes of differing sizes one may wish to rearrange them into a compact mass at one end of the area while revising all pointers to marked nodes to show their new locations an algorithm is described here which accomplishes this task in linear time relative to the size of the storage area and in a space of the order of one bit for each pointer the algorithm operates by reversibly encoding the situation that a collection of locations point to a single location by a linear list emanating from the pointed to location passing through the pointing locations and terminating with the pointed to locations transplanted contents
CACM	fast parallel sorting algorithms a parallel bucket sort algorithm is presented that requires time o log n and the use of n processors the algorithm makes use of a technique that requires more space than the product of processors and time a realistic model is used model is used in which no memory contention is permitted a procedure is also presented to sort n numbers in time o k log n using n 1 1 k processors for k an arbitrary integer the model of computation for this procedure permits simultaneous fetches from the same memory location
CACM	value conflicts and social choice in electronic funds transfer system developments during the last few years computer based systems which automate the transfer and recording of debits and credits have begun to be implemented on a large scale these systems promise both financial benefits for the institutions that use them and potential conveniences to their customers however they also raise significant social legal and technical questions that must be resolved if full scale systems for electronic funds transfer eft are not to cause more problems for the larger public than they solve this paper examines the incentives for eft developments and the social problems they raise in the context of conflicts between five different value positions that are often implicit in analyses of proposed eft arrangements these conflicts reflect the relative importance of certain problems for specific groups the value positions implicit in eft proposals help to organize analyses of market arrangements system reliability and privacy of transactions these topics are analyzed in this article and related to the value positions held by concerned parties last the ways in which the public can learn about the social qualities of different eft arrangements and the pace of eft developments are both discussed in the context of social choice
CACM	can programming be liberated from the von neumann style a functional style and its algebra of programs conventional programming languages are growing ever more enormous but not stronger inherent defects at the most basic level cause them to be both fat and weak their primitive word at a time style of programming inherited from their common ancestor the von neumann computer their close coupling off semantics to state transitions their division of programming into a world of expressions and a world of statements their inability to effectively use powerful combining forms for building new programs from existing ones and their lack of useful mathematical properties for reasoning about programs an alternative functional style of programming is founded on the use of combining forms for creating programs functional programs deal with structured data are often nonrepetitive and nonrecursive are hierarchically constructed do not name their arguments and do not require the complex machinery of procedure declarations to become generally applicable combining forms can use high level programs to build still higher level ones in a style not possible in conventional languages associated with the functional style of programming is an algebra of programs whose variables range over programs and whose operations are combining forms this algebra can be used to transform programs and to solve equations whose unknowns are programs in much the same way one transforms equations in high school algebra these transformations are given by algebraic laws and are carried out in the same language in which programs are written combining forms are chosen not only for their programming power but also for the power of their associated algebraic laws general theorems of of the algebra give the detailed behavior and termination conditions for large classes of programs a new class of computing systems uses the functional programming style both in its programming language and in its state transition rules unlike von neumann languages these systems have semantics loosely coupled to states only one state transition occurs per major computation
CACM	analysis of the availability of computer systems using computer  aided algebra analytical results related to the availability of a computer system constructed of unreliable processors are presented in this paper these results are obtained by using various computer aided algebraic manipulation techniques a major purpose of this paper is to demonstrate that the difficulties of obtaining analytical solutions to markov processes can be considerably reduced by the application of symbol manipulation programs since many physical systems can be modeled by markov and semi markov processes the potential range of application of these techniques is much wider than the problem of availability analyzed here
CACM	an algorithm for reasoning about equality a simple technique for reasoning about equalities that is fast and complete for ground formulas with function symbols and equality is presented a proof of correctness is given as well
CACM	proving the correctness of heuristically optimized code a system for proving that programs written in a high level language are correctly translated to a low level language is described a primary use of the system is as a post optimization step in code generation the low level language programs need not be generated by a compiler and in fact could be hand coded examples of the usefulness of such a system are given some interesting results are the ability to handle programs that implement recursion by bypassing the start of the program and the detection and pinpointing of a wide class of errors in the low level language programs the examples demonstrate that optimization of the genre of this paper can result in substantially faster operation and the saving of memory in terms of program and stack sizes
CACM	shallow binding in lisp 1 5 shallow binding is a scheme which allows the value of a variable to be accessed in a bounded amount of computation an elegant model for shallow binding in lisp 1 5 is presented in which context switching is an environment tree transformation called rerooting rerooting is completely general and reversible and is optional in the sense that a lisp 1 5 interpreter will operate correctly whether or not rerooting is invoked one very context change since rerooting leaves assoc v a invariant for all variables v and all environments a the programmer can have access to a rerooting primitive shallow which gives him dynamic control over whether accesses are shallow or deep and which affects only the speed of execution of a program not its semantics in addition multiple processes can be active in the same environment structure so long as rerooting is an indivisible operation finally the concept of rerooting is shown to combine the concept of shallow binding in lisp with dijkstras display for algol and hence is a general model for shallow binding
CACM	time clocks and the ordering of events in a distributed system the concept of one event happening before another in a distributed system is examined and is shown to define a partial ordering of the events a distributed algorithm is given for synchronizing a system of logical clocks which can be used to totally order the events the use of the total ordering is illustrated with a method for solving synchronization problems the algorithm is then specialized for synchronizing physical clocks and a bound is derived on how far out of synchrony the clocks can become
CACM	pseudochaining in hash tables this paper presents pseudochaining as a new collision resolution method pseudochaining is half way between open addressing and chaining it owes its name to the fact that link fields are present in each cell of the hash table which permits chaining of the first overflow items in the table the efficiency of the method is derived and a tradeoff analysis is given
CACM	interpolation search  a log logn search interpolation search is a method of retrieving a desired record by key in an ordered file by using the value of the key and the statistical distribution of the keys it is shown that on the average log logn file accesses are required to retrieve a key assuming that the n keys are uniformly distributed the number of extra accesses is also estimated and shown to be very low the same holds if the cumulative distribution function of the keys is known computational experiments confirm these results
CACM	an o n algorithm for determining a near optimal computation order of matrix chain products this paper discusses the computation of matrix chain products of the form m1 x m2 x x mn where mis are matrices the order in which the matrices are computed affects the number of operations a sufficient condition about the association of the matrices in the optimal order is presented an o n algorithm to find an order of computation which takes less than 25 percent longer than the optimal time topt is also presented in most cases the algorithm yields the optimal order or an order which takes only a few percent longer than topt less than 1 percent on the average
CACM	on the complexity of computing the measure of u ai bi the decision tree complexity of computing the measure of the union of n possibly overlapping intervals is shown to be n log n even if comparisons between linear functions of the interval endpoints are allowed the existence of an n log n lower bound to determine whether any two of n real numbers are within of each other is also demonstrated these problems provide an excellent opportunity for discussing the effects of the computational model on the ease of analysis and on the results produced
CACM	an english language question answering system for a large relational database by typing requests in english casual users will be able to obtain explicit answers from a large relational database of aircraft flight and maintenance data using a system called planes the design and implementation of this system is described and illustrated with detailed examples of the operation of system components and examples of overall system operation the language processing portion of the system uses a number of augmented transition networks each of which matches phrases with a specific meaning along with context registers his tory keepers and concept case frames these are used for judging meaningfulness of questions generating dialogue for clarifying partially understood questions and resolving ellipsis and pronoun reference problems other system components construct a formal query for the relational database and optimize the order of searching relations methods are discussed for handling vague or complex questions and for providing browsing ability also included are discussions of important issues in programming natural language systems for limited domains and the relationship of this system to others
CACM	general equations for idealized cpu i o overlap configurations general equations are derived for estimating the maximum possible utilization of main storage partitions cpu and i o devices under different conditions in an idealized cpu i o overlap model of multiprogrammed computer systems the equations are directly applicable to any configuration consisting of sets of identical cpus i o processors main storage partitions and user tasks examples are provided to illustrate the use of the equations to compute effective processing time per record and expected timesharing response time under both balanced and unbalanced resource utilization conditions
CACM	performance of rollback recovery systems under intermittent failures a mathematical model of a transaction oriented system under intermittent failures is proposed the system is assumed to operate with a checkpointing and rollback recovery method to ensure reliable information processing the model is used to derive the principal performance measures including availability response time and the system saturation point
CACM	automated welfare client tracking and service integration the political economy of computing the impacts of an automated client tracking system on the clients caseworkers administrators and operations of the welfare agencies that use it are reported the major impact of this system was to enhance the administrative attractiveness of the using agencies in the eyes of funders rather than to increase their internal administrative efficiency this impact is a joint product of both the technical features of the computer based system and of the organizational demands placed upon different agencies administrators and caseworkers it illustrates the way successful automated information systems fit the political economies of the groups that use them
CACM	some basic determinants of computer programming productivity the propose of this research was to examine the relationship between processing characteristics of programs and experience characteristics of programmers and program development time the ultimate objective was to develop a technique for predicting the amount of time necessary to create a computer program the fifteen program characteristics hypothesized as being associated with an increase in programming time required are objectively measurable from preprogramming specifications the five programmer characteristics are experience related and are also measurable before a programming task is begun nine program characteristics emerged as major influences on program development time each associated with increased program development time all five programmer characteristics were found to be related to reduced program development time a multiple regression equation which contained one programmer characteristic and four program characteristics gave evidence of good predictive power for forecasting program development time
CACM	characteristics of application software maintenance maintenance and enhancement of application software consume a major portion of the total life cycle cost of a system rough estimates of the total systems and programming resources consumed range as high as 75 80 percent in each category however the area has been given little attention in the literature to analyze the problems in this area a questionnaire was developed and pretested it was then submitted to 120 organizations respondents totaled 69 responses were analyzed with the spss statistical package the results of the analysis indicate that 1 maintenance and enhancement do consume much of the total resources of systems and programming groups 2 maintenance and enhancement tend to be viewed by management as at least somewhat more important than new application software development 3 in maintenance and enhancement problems of a management orientation tend to be more significant than those of a technical orientation and 4 user demands for enhancements and extension constitute the most important management problem area
CACM	automatic error recovery for lr parsers in this paper we present a scheme for detecting and recovering from syntax errors in programs the scheme which is based on lr parsing is driven by information which is directly and automatically obtainable from the information that is already present in an lr parser the approach which is patterned after that of levy and graham and rhodes appears to provide error recovery which is both simple and powerful
CACM	analyses of deterministic parsing algorithms this paper describes an approach for determining the minimum maximum and average times to parse sentences acceptable by a deterministic parser these quantities are presented in the form of symbolic formulas called time formulas the variables in these formulas represent not only the length of the input string but also the time to perform elementary operations such as pushing popping subscripting iterating etc by binding to the variables actual numerical values corresponding to a given compiler machine configuration one can determine the execution time for that configuration time formulas are derived by examining the grammar rules and the program representing the algorithm one wishes to analyze the approach is described by using a specific grammar that defines simple arithmetic expressions two deterministic parsers are analyzed a top down recursive descent ll 1 parser and a bottom up slr 1 parser the paper provides estimates for the relative efficiencies of the two parsers the estimates applicable to a specific machine the pdp 10 are presented and substantiated buy benchmarks finally the paper illustrates the proposed approach by applying it to the analyses of parsers for a simple programming language
CACM	a selective traversal algorithm for binary search trees the problem of selecting data items from a binary search tree according to a list of range conditions is considered the process of visiting a minimal number of nodes to retrieve data satisfying the range conditions is called selective traversal presented in this paper is an algorithm for selective traversal which uses a tag field for each node in the tree the algorithm is particularly useful and efficient when examination of data is more time consuming than examination of a tag field
CACM	an optimal method for deletion in one sided height balanced trees a one sided height balanced tree is a binary tree in which every nodes right subtree has a height which is equal to or exactly one greater than the height of its left subtree it has an advantage over the more general avl tree in that only one bit of balancing information is required two bits are required for the acl tree it is shown that deletion of an arbitrary node of such a tree can be accomplished in o logn operations where n is the number of nodes in the tree moreover the method is optimal in the sense that its complexity cannot be reduced in order of magnitude this result coupled with earlier results by hirschberg indicates that of the three basic problems of insertion deletion and retrieval only insertion is adversely affected by this modification of an avl tree
CACM	optimal shift strategy for a block transfer ccd memory for the purposes of this paper a block transfer ccd memory is composed of serial shift registers whose shift rate can vary but which have a definite minimum shift rate the refresh rate and a definite maximum shift rate the bits iin the shift registers are numbered 0 to n   1 and blocks of n bits are always transferred always starting at bit 0 what is the best shift strategy so that a block transfer request occurring at a random time will have to wait the minimal amount of time before bit 0 can be reached the minimum shift rate requirement does not allow one to simply park at bit 0 and wait for a transfer request the optimal strategy involves shifting as slowly as possible until bit 0 is passed then shifting as quickly as possible until a critical boundary is reached shortly before bit 0 comes around again this is called the hurry up and wait strategy and is well known outside the computer field the block transfer ccd memory can also be viewed as a paging drum with a variable bounded rotation speed
CACM	computer generation of gamma random variables a new method for generating random variables from the gamma distribution with nonintegral shape parameter a is proposed this method is similar to two other methods recently given by wallace and fishman it is compared with fishmans and ahrens and dieters methods the core storage requirements and programming effort for this method are similar to those of fishmans method the proposed method is the same as fishmans method for 1 a 2 and is faster than fishmans method for 3 a 19 also the proposed method is much simpler than ahrens and dieters method and is faster for a 8
CACM	new sufficient optimality conditions for integer programming and their application the purpose of this report is to present a new class of sufficient optimality conditions for pure and mixed integer programming problems some of the sets of sufficient conditions presented can be thought of as generalizations of optimality conditions based on primal dual complementarity in linear programming these sufficient conditions are particularly useful for the construction of difficult integer programming problems with known optimal solutions these problems may then be used to test and or benchmark integer programming codes
CACM	an interference matching technique for inducing abstractions a method for inducing knowledge by abstraction from a sequence of training examples is described the proposed method interference matching induces abstractions by finding relational properties common to two or more exemplars three tasks solved by a program that uses an interference matching algorithm are presented several problems concerning the description of the training examples and the adequacy of interference matching are discussed and directions for future research are considered
CACM	the sl5 procedure mechanism this paper describes an integrated procedure mechanism that permits procedures to be used as recursive functions or as coroutines this integration is accomplished by treating procedures and their activation records called environments as data objects and by decomposing procedure invocation into three separate components at the source language level in addition argument binding is under the control of the programmer permitting the definition of various methods of argument transmission in the source language itself the resulting procedure mechanism which is part of the sl5 programming language is well suited to goal oriented problems and to other problems that are more readily programmed by using coroutines several examples are given
CACM	incorporation of units into programming languages the issues of how a programming language might aid in keeping track of physical units feet sec etc are discussed a method is given for the introduction of relationships among units a watt is volts amps a yard is three feet and subsequent automatic conversion based upon these relationships various proposals for syntax are considered
CACM	automatic data structure selection an example and overview the use of several levels of abstraction has proved to be very helpful in constructing and maintaining programs when programs are designed with abstract data types such as sets and lists programmer time can be saved by automating the process of filling in low level implementation details in the past programming systems have provided only a single general purpose implementation for an abstract type thus the programs produced using abstract types were then inefficient in space or time in this paper a system for automatically choosing efficient implementations for abstract types from a library of implementations is discussed this process is discussed in detail for an example program general issues in data structure selection are also reviewed
CACM	test data as an aid in proving program correctness proofs of program correctness tend to be long and tedious whereas testing though useful in detecting errors usually does not guarantee correctness this paper introduces a techniques whereby test data can be used in proving program correctness in addition to simplifying the process of proving correctness this method simplifies the process of providing accurate specification for a program the applicability of this technique to procedures and recursive programs is demonstrated
CACM	a language extension for expressing constraints on data access controlled sharing of information is needed and desirable for many applications and is supported in operating systems by access control mechanisms this paper shows how to extend programming languages to provide controlled sharing the extension permits expression of access constraints on shared data access constraints can apply both to simple objects and to objects that are components of larger objects such as bank account records in a banks data base the constraints are stated declaratively and can be enforced by static checking similar to type checking the approach can be used to extend any strongly typed language but is particularly suitable for extending languages that support the notion of abstract data types
CACM	a fast algorithm for copying list structures an algorithm is presented for copying an arbitrarily linked list structure into a block of contiguous storage locations without destroying the original list apart from a fixed number of program variables no auxiliary storage such as a stack is used the algorithm needs no mark bits and operates in linear time it is shown to be significantly faster than fishers algorithm the fastest previous linear time algorithm for the same problem its speed comes mainly from its efficient list traversal technique which folds the processing stack into the structure being built and from its classification of list cells into nine types which enables processing operations to be optimized for each type
CACM	generating beta variates with nonintegrel shape parameters a new rejection method is described for generating beta variates the method is compared with previously published methods both theoretically and through computer timings it is suggested that the method has advantages in both speed and programming simplicity over previous methods especially for difficult combinations of parameter values
CACM	economical encoding of commas between strings a method for insertion of delimiters between strings without using new symbols is presented as the lengths of the strings increase the extra cost in terms of prolongation becomes vanishingly small compared to the lengths of the strings
CACM	a data structure for manipulating priority queues a data structure is described which can be used for representing a collection of priority queues the primitive operations are insertion deletion union update and search for an item of earliest priority
CACM	assembling code for machines with span dependent instructions many modern computers contain instructions whose lengths depend on the distance from a given instance of such an instruction to the operand of that instruction this paper considers the problem of minimizing the lengths of programs for such machines an efficient solution is presented for the case in which the operand of every such span dependent instruction is either a label or an assembly time expression of a certain restricted form if this restriction is relaxed by allowing these operands to be more general assembly time expressions then the problem is shown to be np complete
CACM	secure communications over insecure channels according to traditional conceptions of cryptographic security it is necessary to transmit a key by secret means before encrypted messages can be sent securely this paper shows that it is possible to select a key over open communications channels in such a fashion that communications security can be maintained a method is described which forces any enemy to expend an amount of work which increases as the square of the work required of the two communicants to select the key the method provides a logically new kind of protection against the passive eaves dropper it suggests that further research on this topic will be highly rewarding both in a theoretical and a practical sense
CACM	list processing in real time on a serial computer a real time list processing system is one in which the time required by the elementary list operations e g cons car cdr rplaca replacd eq and atom in lisp is bounded by a small constant classical implementations of list processing systems lack this property because allocating a list cell from the heap may cause a garbage collection which process requires time proportional to the heap size to finish a real time list processing system is presented which continuously reclaims garbage including directed cycles while linearizing and compacting the accessible cells into contiguous locations to avoid fragmenting the free storage pool the program is small and requires no time sharing interrupts making it suitable for microcode finally the system requires the same average time and not more than twice the space of a classical implementation and those space requirements can be reduced to approximately classical proportions by compact list representation arrays of different sizes a program stack and hash linking are simple extensions to our system and reference counting is found to be inferior for many applications
CACM	optimal conversion of extended entry decision tables with general cost criteria a general dynamic programming algorithm for converting limited extended or mixed entry decision tables to optimal decision trees is presented which can take into account rule frequencies or probabilities minimum time and or space cost criteria common action sets compressed rules and else rules sequencing constraints on condition tests excludable combinations of conditions certain ambiguities and interrupted rule masking
CACM	a technique for isolating differences between files a simple algorithm is described for isolating the differences between two files one application is the comparing of two versions of a source program or other file in order to display all differences the algorithm isolates differences in a way that corresponds closely to our intuitive notion of difference is easy to implement and is computationally efficient with time linear in the file length for most applications the algorithm isolates differences similar to those isolated by the longest common subsequence another application of this algorithm merges files containing independently generated changes into a single file the algorithm can also be used to generate efficient encodings of a file in the form of the differences between itself and a given datum file permitting reconstruction of the original file from the difference and datum files
CACM	orderly enumeration of nonsingular binary matrices applied to text encryption nonsingular binary matrices of order n i e nonsingular over the field 0 1 and an initial segment of the natural numbers are placed in one to one correspondence each natural number corresponds to two intermediate vectors these vectors are mapped into a nonsingular binary matrix examples of complete enumeration of all 2 x 2 and 3 x 3 nonsingular binary matrices were produced by mapping the intermediate vectors to the matrices the mapping has application to the vernam encipherment method using pseudorandom number sequences a bit string formed form bytes of text of a data encryption key can be used as a representation of a natural number this natural number is transformed to a nonsingular binary matrix key leverage is obtained by using the matrix as a seed in a shift register sequence pseudorandom number generator
CACM	interference detection among solids and surfaces in many industrial environments it is necessary to determine whether r there is interference among components there are many potential interference problems in products made up of assemblies of components and in product manufacturing and testing typically drawings are used in an attempt to detect such unwanted interferences but the two dimensional static drafting medium does not always show interferences among three dimensional moving parts this paper presents a computer representation for solids and surfaces and algorithms which carry out interference checking among objects so represented objects are represented as polyhedra or as piecewise planar surfaces two types of interference checking are discussed detection of intersections among objects in fixed positions and detection of collisions among objects moving along specified trajectories
CACM	the impact and use of computer technology by the police over the past decade there has been a significant growth in the use of computer technology by u s police departments this growth however has been at a slower rate than predicted in the early 1970s further when computer applications extend beyond routine uses to nonroutine efforts such as resource allocation or computer aided dispatch systems where the machine begins to become a tool for decision making strategic planning and person machine interaction the results of the technology to date have been mixed this paper reports on case studies and surveys which provinsights on the implementation and impact of police computer technology and the relationship of this technology to law enforcement and society
CACM	permutation of data blocks in a bubble memory a common internal organization of bubble memories consists of a set of minor loops connected through another major loop the problem of obtaining any give n permutation of the minor loop contents in minimum time is studied in this paper a lower bound to the number of steps required buy a permutation algorithm is derived and the class of optimum algorithms is identified
CACM	the impact of distributions and disciplines on multiple processor systems simple queueing models are used to study the performance tradeoffs of multiple processor systems issues considered include the impact of cpu service disciplines and distributions level of multiprogramming multitasking and job priorities
CACM	an event driven compiling technique due to the linear structure of source text difficulties may arise in a one pass compilation process these difficulties occur when an entity cannot be processed because of a forward reference to information only obtainable from subsequent entities classic solutions ask for data structures appropriate for each case a technique is presented here which uses instead control structures namely events and processes the work of the compiler writer becomes easier both conceptually and in practice because he can forget these problems at the outset and he avoids special processing for each problem this technique has been applied to the construction of an algol 68 compiler three examples from that implementation are described and discussed here
CACM	syntactic source to source transforms and program manipulation syntactic transforms are the source to source program transformations which preserve the history of computation and thus do not modify the execution time combined with a small number of primitive semantic transforms they provide a powerful tool for program manipulation a catalogue of syntactic transforms and its use for solution of a system of program equations is given examples of derivation of more complex source to source transformations are also presented two case studies illustrate the way in which syntactic and semantic source to source transformations may be used for development of clear simple and reasonably efficient programs
CACM	production and employment of ph d s in computer science   1977 and 1978
CACM	employment characteristics of doctoral level computer scientists
CACM	recursive data structures in apl a mathematical study of three approaches for defining nested arrays in apl is presented theorems exhibiting the relationships between the definitional systems are given and illustrated through graph representations one of the approaches is used to define an apl array to be a recursive data structure equivalent to a tree structure in which all data is stored at the leaves as homogeneous arrays of numbers and characters an extension of apl is proposed that includes new primitive functions to manipulate the nesting level of arrays and new operators to assist in the construction of data driven algorithms
CACM	global optimization by suppression of partial redundancies the elimination of redundant computations and the moving of invariant computations out of loops are often done separately with invariants moved outward loop by loop we propose to do both at once and to move each expression directly to the entrance of the outermost loop in which it is invariant this is done by solving a more general problem i e the elimination of computations performed twice on a given execution path such computations are termed partially redundant moreover the algorithm does not require any graphical information or restrictions on the shape of the program graph testing this algorithm has shown that its execution cost is nearly linear with the size of the program and that it leads to a smaller optimizer that requires less execution time
CACM	comments on perfect hashing functions a single probe retrieving method for static sets
CACM	thoth a portable real time operating system thoth isa real time operating system which is designed to be portable over a large set of machines it is currently running on two minicomputers with quite different architectures both the system and application programs which use it are written in a high level language because the system is implemented by the same software on different hardware it has the same interface to user programs hence application programs which use thoth are highly portable thoth encourages structuring programs as networks of communicating processes by providing efficient interprocess communication primitives
CACM	synchronization with eventcounts and sequencers synchronization of concurrent processes requires controlling the relative ordering of events in the processes a new synchronization mechanism is proposed using abstract objects called eventcounts and sequencers that allows processes to control the ordering of events directly rather than using mutual exclusion to protect manipulations of shared variables that control ordering of events direct control of ordering seems to simplify correctness arguments and also simplifies implementation in distributed systems the mechanism is defined formally and then several examples of its use are given the relationship of the mechanism to protection mechanisms in the system is explained in particular eventcounts are shown to be applicable to situations where confinement of information matters an implementation of eventcount s and sequencers in a system with shared memory is described
CACM	optimal storage allocation for serial files a computer system uses several serial files the files reside on a direct access storage device in which storage space is limited records are added to the files either by jobs in batch processing mode or by on line transactions each transaction or job generates a demand vector which designates the space required in each file for record addition whenever one file runs out of space the system must be reorganized this paper considers several criteria for best allocating storage space to the files
CACM	curriculum 78   recommendations for the undergraduate program in computer science contained in this report are the recommendations for the undergraduate degree program in computer science of the curriculum committee on computer science c3s of the association for computing machinery acm the core curriculum common to all computer science undergraduate programs is presented in terms of elementary level topics and courses and intermediate level courses elective courses used to round out an undergraduate program are then discussed and the entire program including the computer science component and other material is presented issues related to undergraduate computer science education such as service courses supporting areas continuing education facilities staff and articulation are presented
CACM	focus microcomputer number system focus is a number system and supporting computational algorithms especially useful for microcomputer control and other signal processing applications focus has the wide ranging character of floating point numbers with a uniformity of state distributions that give focus better than a twofold accuracy advantage over an equal word length floating point system focus computations are typically five times faster than single precision fixed point or integer arithmetic for a mixture of operations comparable in speed with hardware arithmetic for many applications algorithms for 8 bit and 16 bit implementations of focus are included
CACM	experiments with some algorithms that find central solutions for pattern classification in two class pattern recognition it is a standard technique to have an algorithm finding hyperplanes which separates the two classes in a linearly separable training set the traditional methods find a hyperplane which separates all points in the other but such a hyperplane is not necessarily centered in the empty space between the two classes since a central hyperplane does not favor one class or the other it should have a lower error rate in classifying new points and is therefore better than a noncentral hyperplane six algorithms for finding central hyperplanes are tested on three data sets although frequently used practice the modified relaxation algorithm is very poor three algorithms which are defined in the paper are found to be quite good
CACM	logic and semantic networks an extended form of semantic network is defined which can be regarded as a syntactic variant of the clausal form of logic by virtue of its relationship with logic the extended semantic network is provided with a precise semantics inference rules and a procedural interpretation on the other hand by regarding semantic networks as an abstract data structure for the representation of clauses we provide a theorem prover with a potentially useful indexing scheme and path following strategy for guiding the search for a proof
CACM	the use of normal multiplication tables for information storage and retrieval this paper describes a method for the organization and retrieval of attribute based information systems using the normal multiplication table as a directory for the information system algorithms for the organization an d retrieval of information are described this method is particularly suitable for queries requesting a group of information items all of which possess a particular set of attributes and possibly some other attributes as well several examples are given the results with respect to the number of disk accesses and disk space are compared to other common approaches algorithms evaluating the appropriateness of the above approach to a given information system are described for a certain class of information systems the normal multiplication table method yields far more rapid retrieval with a more economical space requirement than conventional systems moreover this method incorporates an improved modification of the inverted file technique
CACM	detection of three dimensional patterns of atoms in chemical structures an algorithm for detecting occurrences of a three dimensional pattern of objects within a larger structure is presented the search technique presented uses the geometric structure of the pattern to define characteristics demanded of candidates for matching this is useful in cases where the properties of each atom considered individually do not adequately limit the number of sets of possible matchings several applications of this technique in the field of chemistry are 1 in pharmacology searching for a common constellation of atoms in molecules possessing similar biological activities 2 in x ray crystallography fitting a structure or a structural fragment to a set of peaks in the electron density distribution of a fourier map 3 in chemical documentation retrieving from a file the structures containing specified substructures
CACM	price performance patterns of u s computer systems econometric models of the u s computer market have been developed to study the relationships between system price and hardware performance single measures of price performance such as groschs law are shown to be so over simplified as to be meaningless multiple regression models predicting system cost as a function of several hardware characteristics do however reveal a market dichotomy on one hand there exists a stable price predictable market for larger general purpose computer systems the other market is the developing one for small business computer systems a market which is relatively unstable with low price predictability
CACM	a methodology for the design of distributed information systems a macro model of a distributed information system in presented the model describes the major costs of using an information system from the perspective of the end user the making evident the effect of various design and operating parameters on overall cost per transaction the technique is illustrated by application to the design of an interactive transaction processing system
CACM	a mathematical programming updating method using modified givens transformations and applied to lp problems an efficient and numerically stable method is presented for the problem of updating an orthogonal decomposition of a matrix of column or row vectors the fundamental idea is to add a column or row analogous to adding an additional row of data in a linear least squares problem a column or row is dropped by a formal scaling with the imaginary unit  1 followed by least squares addition of the column or row the elimination process for the procedure is successive ssive application of the givens transformation in modified more efficient form these ideas are illustrated with an implementation of the revised simplex method the algorithm is a general purpose one that does not account for any particular structure or sparsity in the equations some suggested computational tests for determining signs of various controlling parameters in the revised simplex algorithm are mentioned a simple means of constructing test cases and some sample computing times are presented
CACM	new methods to color the vertices of a graph this paper describes efficient new heuristic methods to color the vertices of a graph which rely upon the comparison of the degrees and structure of a graph a method is developed which is exact for bipartite graphs and is an important part of heuristic procedures to find maximal cliques in general graphs finally an exact method is given which performs better than the randall brown algorithm and is able to color larger graphs and the new heuristic methods the classical methods and the exact method are compared
CACM	social processes and proofs of theorems and programs it is argued that formal verifications of programs no matter how obtained will not play the same key role in the development of computer science and software engineering as proofs do in mathematics furthermore the absence of continuity the inevitability of change and the complexity of specification of significantly many real programs make the form al verification process difficult to justify and manage it is felt that ease of formal verification should not dominate program language design
CACM	an improved algorithm for decentralized extrema finding in circular configurations of processes this note presents an improvement to lelanns algorithm for finding the largest or smallest of a set of uniquely numbered processes arranged in a circle in which no central controller exists and the number of processes is not known a priori this decentralized algorithm uses a technique of selective message extinction in order to achieve an average number of message passes of order n log n rather than o n2
CACM	consumer difficulties with computerized transactions an empirical investigation the prevalence with which errors may be encountered by the end targets of a computerized process is assessed how many and what type of errors occur how easily are they corrected what is the reaction of consumers to errors to a failure to correct them what can be learned by designers of large management packages from such data results show that with the present state of the art approximately 40 percent of individuals or households having average contacts with different types of accounts experience one or more errors per year eighty percent relate to billing attempts to correct errors often turned out to be difficult and not always successful there appears to be some conflict between computer using organizations and their public also the role of poor man agement packages including poor software is indicated while most management systems may be adequate results of the survey raise concerns about the timeliness and the number of designs of very large linked program packages as eft for instance
CACM	reasoning about arrays a variety of concepts laws and notations are presented which facilitate reasoning about arrays the basic concepts include intervals and their partitions functional restriction images pointwise extension of relations ordering single point variation of functions various equivalence relations for array values and concatenation the effectiveness of these ideas is illustrated by informal descriptions of algorithms for binary search and merging and by a short formal proof
CACM	a model for and discussion of multi interpreter systems a multi interpreter system is a system in which programs execute by virtue of being interpreted by other programs which themselves may either be interpreted i e nested interpreters or run directly on the host machine the model reveals the anatomy of interpreters and how these differ from procedures and exhibits links to protection domains and multiprocessor architectures
CACM	an implementation of structured walk throughs in teaching cobol programming the effectiveness of structured walk throughs in teaching introductory cobol programming was empirically assessed with a sample of 215 under graduate business administration majors cobol proficiency was measured by a final examination testing a knowledge of language rules b ability to read and debug a program and c the ability to write a program analysis of multiple covariance was used to statistically adjust test scores for age and conditional reasoning scores the findings provide empirical support for incorporating structured walk throughs into the programming learning process more effectively develop student proficiency in writing cobol programs
CACM	an academic program providing realistic training in software engineering an academic program at harvey mudd college called the clinic program brings projects from industry on campus to be studied and solved by student teams the objective of the clinic is to provide students working as small teams under careful faculty supervision an opportunity to work on real world problems of sufficient magnitude and complexity under this program students can acquire essential skills of software engineering such as team work software project management software design methodology and communication skills in a realistic environment sample software projects undertaken by the clinic are described experience so far has shown that the program is a viable transition from an academic to industrial world
CACM	a model for automating file and program design in business application systems this paper discusses a model for finding an efficient implementation of a business application system whose logical specifications have been determined in advance the model views file and program design as a problem of systematically coordinating the configurations of datasets and computations it uses a straight forward search technique to determine aggregations of computations aggregations of datasets device organization and key order for each data set key order for each computation and access method for each dataset computation pair although computational results are presented for a sample problem involving 54 computations and 49 datasets the main point of the paper is that the underlying model works computationally an d is simple enough to be adapted to many file design situations
CACM	high level programming for distributed computing programming for distributed and other loosely coupled systems is a problem of growing interest this paper describes an approach to distributed computing at the level of general purpose programming languages based on primitive notions of module message and transaction key the methodology is shown to be independent of particular languages and machines it appears to be useful for programming a wide range of tasks this is part of an ambitious program of development in advanced programming languages and relations with other aspects of the project are also discussed
CACM	the cyclic order property of vertices as an aid in scene analysis a cyclic order property is defined for bodies bounded by smooth curved faces the property is shown to be useful for analyzing pictures of such bodies particularly when the line data extracted from the pictures are imperfect this property augments previously known grammatical rules that determine the existence of three dimensional bodies corresponding to given two dimensional line structure data
CACM	beyond programming languages as computer technology matures our growing ability to create large systems is leading to basic changes in the nature of programming current programming language concepts will not be adequate for building and maintaining systems of the complexity called for by the tasks we attempt just as high level languages enabled the programmer to escape from the intricacies of a machines order code higher level programming systems can provide the means to understand and manipulate complex systems and components in order to develop such systems we need to shift our attention away from the detailed specification of algorithms towards the description of the properties of the packages and objects with which we build this paper analyzes some of the shortcomings of programming languages as they now exist and lays out some possible directions for future research
CACM	an optimal real time algorithm for planar convex hulls an algorithm is described for the construction in real time of the convex hull of a set of n points in the plane using an appropriate data structure the algorithm constructs the convex hull by successive updates each taking time o log n thereby achieving a total processing time o n log n
CACM	storage reorganization techniques for matrix computation in a paging environment in order to multiply matrices while minimizing the number of page fetches required it is often more efficient to reorganize the data into submatrix form and to use block multiplication rather than to use the best known algorithms which leave the matrices stored in row  or column  oriented form an efficient method for accomplishing this reorganization is given this also makes possible the derivation of an asymptotically better bound for multiplication of matrices given in row oriented form by adapting the technique of strassen to the reorganized data the reorganization block multiplication scheme is shown to be advantageous for matrices and pages of realistic size the strassen adaptation is not the former scheme is also shown to be advantageous even if the transpose of one of the matrices is available at no additional cost
CACM	the control of response times in multi class systems by memory allocations the possibility of giving different quality of service to jobs of different classes by regulating their memory allocation is examined in the context of a paged computer system two parameterized algorithms which partition the main memory between two classes of jobs are considered initially a closed system consisting of a process or and paging and file devices with fixed numbers of jobs is studied to determine optimal degrees of multiprogramming and the proportion of processor time devoted to each class applying a decomposition approach and treating the closed system as a single server the response times in an open system with external arrivals are studied the object is to investigate the effect of the memory alocation parameters on the expected response times under the two algorithms numerical solutions and economical lower bounds for the expected response times as functions of the control parameters are obtained a way of applying the results to systems with more than two job classes is indicated
CACM	algorithm logic control an algorithm can be regarded as consisting of a logic component which specifies the knowledge to be used in solving problems and a control component which determines the problem solving strategies by means of which that knowledge is used the logic component determines the meaning of the algorithm whereas the control component only affects its efficiency the efficiency of an algorithm can often by improving the control component without changing the logic of the algorithm we argue that computer programs would be more often correct and more easily improved and modified if their logic and control aspects were identified and separated in the program text
CACM	the paradigms of programming
CACM	computing connected components on parallel computers we present a parallel algorithm which uses n2 processors to find the connected components of an undirected graph with n vertices in time o log2n an o log2n time bound also can be achieved using only n n log2n processors the algorithm can be used to find the transitive closure of a symmetric boolean matrix we assume that the processors have access to a common memory simultaneous access to the same location is permitted for fetch instructions but not for store instructions
CACM	proving termination with multiset orderings a common tool for proving the termination of programs is the well founded set a set ordered in such a way as to admit no infinite descending sequences the basic approach is to find a termination function that maps the values of the program variables into some well founded set such that the value of the termination function is repeatedly reduced throughout the computation all too often the termination functions required are difficult to find and are of a complexity out of proportion to the program under consideration multisets bags over a given well founded set s are sets that admit multiple occurrences of elements taken from s the given ordering on s induces an ordering on the finite multisets over s this multiset ordering is shown to be well founded the multiset ordering enables the use of relatively simple and intuitive termination functions in otherwise difficult termination proofs in particular the multiset ordering is used to prove the termination of production systems programs defined in terms of sets of rewriting rules
CACM	secure personal computing in an insecure network a method for implementing secure personal computing in a network with one or more central facilities is proposed the method employs a public key encryption device and hardware keys each user is responsible for his own security and need not rely on the security of the central facility or the communication links a user can safely store confidential files in the central facility or transmit confidential data to other users on the network
CACM	further remark on stably updating mean and standard deviation estimates
CACM	rejuvenating experimental computer science this report is based on the results of an nsf sponsored workshop held in wasington d c on november 2 1978 the co authors of the report are gordon bell digital equipment corporation bernard a galler university of michigan patricia goldberg ibm corporation john hamblen university of missouri at rolla elliot pinson bell telephone laboratories and ivan sutherland california institute of technology also participating in the workshop were representatives of nsf and other government agencies in addition to the authors a number of other people have contributed to the contents of this report in preparation for the original workshop all doctorate granting computer science departments in the nation were asked for comments and suggestions on the problems of experimental computer science a version of the current report dated january 15 was circulated to these departments and to a number of industrial and government groups for criticism the editors and authors of this final version gratefully acknowledge the contribution of a large number of other people at all stages in the preparation of the report note following this presentation of the report there is a position paper on the crisis in experimental computer science written by the acm executive committee
CACM	an acm executive committee position on the crisis in experimental computer science
CACM	on improving the worst case running time of the boyer moore string matching algorithm it is shown how to modify the boyer moore string matching algorithm so that its worst case running time is linear even when multiple occurrences of the pattern are present in the text
CACM	an optimal insertion algorithm for one sided height balanced binary search trees an algorithm for inserting an element into a one sided height balanced oshb binary search tree is presented the algorithm operates in time o log n where n is the number of nodes in the tree this represents an improvement over the best previous ly known insertion algorithms of hirschberg and kosaraju which require time o log 2n moreover the o log n complexity is optimal earlier results have shown that deletion in such a structure can also be performed in o log n time thus the result of this paper gives a negative answer to the question of whether such trees should be the first examples of their kind where deletion has a smaller time complexity than insertion furthermore it can now be concluded that insertion deletion and retrieval in oshb trees can be performed in the same time as the corresponding operations for the more general avl trees to within a constant factor however the insertion and deletion algorithms for oshb trees appear much more complicated than the corresponding algorithms for avl trees
CACM	progressive acyclic digraphs a tool for database integrity a progressive acyclic digraph pad algorithm accepts are requests and maintains a graph in an acyclic state when a request creates a cycle nodes are detached until the new are can be entered acyclically this process is important in certain areas of database implementation in which there are constraints on the permissible sequences of actions two pad algorithms are presented one uses a simple path matrix representation and the other uses a list with an artificial gradient experiments suggest that for large n the second is considerably faster though both are asymptotically o nr where n is the number of nodes and r is the expected number of nodes reachable along paths from any given node
CACM	approximation of polygonal maps by cellular maps the approximation of polygonal thematic maps by cellular maps an important operation in geographical data processing is analyzed the data organization used for representing the polygonal maps is a widely used segment based data structure where class labels identify the regions bordering each segment on either side the approximation algorithm presented operates on such an organization eliminating the need for the recognition of region boundaries each segment is examined only once the versatility of the new organization is further illustrated by the outline of algorithms for area computation and point inclusion the algorithm is applied to a set of soil maps converted to computer readable form by means of a coordinate digitizer
CACM	computing standard deviations accuracy four algorithms for the numerical computation of the standard deviation of unweighted sampled data are analyzed two of the algorithms are well known in the statistical and computational literature the other two are new algorithms specifically intended for automatic computation our discussion is expository with emphasis on reaching a suitable definition of accuracy each of the four algorithms is analyzed for the conditions under which it will be accurate we conclude that all four algorithms will provide accurate answers for many problems but two of the algorithms one new one old are substantially more accurate on difficult problems than are the other two
CACM	updating mean and variance estimates an improved method a method of improved efficiency is given for updating the mean and variance of weighted sampled data when an additional data value is included in the set evidence is presented that the method is stable and at least as accurate as the best existing updating method
CACM	comment on an optimal evaluation of boolean expressions in an online query system
CACM	note on an optimal evaluation of boolean expressions in an online query system
CACM	on the proof of correctness of a calendar program a formal specification is given for a simple calendar program and the derivation and proof of correctness of the program are sketched the specification is easy to understand and its correctness is manifest to humans
CACM	line numbers made cheap a technique is described for run time line number administration to be used for implementations of high level languages under suitable circumstances this method requires absolutely no overhead in either time or space during execution of the program
CACM	an algorithm for planning collision free paths among polyhedral obstacles this paper describes a collision avoidance algorithm for planning a safe path for a polyhedral object moving among known polyhedral objects the algorithm transforms the obstacles so that they represent the locus of forbidden positions for an arbitrary reference point on the moving object a trajectory of this reference point which avoids all forbidden regions is free of collisions trajectories are found by searching a network which indicates for each vertex in the transformed obstacles which other vertices can be reached safely
CACM	a psychology of learning basic this paper addresses the question what does a person know following learning of basic programming several underlying conceptual structures are identified 1 a transaction is an event that occurs in the computer and involves some operation on some object at some location 2 a prestatement is a set of transactions corresponding to a line of code 3 chunks are frequently occurring configurations of prestatements corresponding to several lines of code
CACM	password security a case history this paper describes the history of the design of the password security scheme on a remotely accessed time sharing system the present design was the result of countering observed attempts to penetrate the system the result is a compromise between extreme security and ease of use
CACM	breaking substitution ciphers using a relaxation algorithm substitution ciphers are codes in which each letter of the alphabet has one fixed substitute and the word divisions do not change in this paper the problem of breaking substitution ciphers is represented as a probabilistic labeling problem every code letter is assigned probabilities of representing plain text letters these probabilities are updated in parallel for all code letters using joint letter probabilities iterating the updating scheme results in improved estimates that finally lead to breaking the cipher the method is applies successfully to two examples
CACM	storing a sparse table the problem of storing and searching large sparse tables is ubiquitous in computer science the standard technique for storing such tables is hashing but hashing has poor worst case performance we propose a good worst case method for storing a static table of n entries each an integer between 0 and n   1 the method requires 0 n w words of storage and allows o logn n access time although our method is a little complicated to use in practice our analysis shows why a simpler algorithm used for compressing lr parsing tables works so well
CACM	how to share a secret in this paper we show how to divide data d into n pieces in such a way that d is easily reconstructable from any k pieces but even complete knowledge of k   1 pieces reveals olutely no information about d this technique enables the construction of robust key management schemes for cryptographic systems that can function securely and reliably even when misfortunes destroy half the pieces and security breaches expose all but one of the remaining pieces
CACM	introduction to the eft symposium
CACM	overview of the eft symposium it is increasingly recognized that large scale technologies such as eft have the potential for aiding in the solution of current societal problems yet these technologies also generate problems this symposium presents selected papers from a conference that sought to discover what is currently known about eft impacts in society and what research is needed in the future
CACM	costs of the current u s payments system neither the banking industry nor public policy makers have good information on the comparative costs of alternative payment systems such as cash checks credit cards and eft transactions as a result eft systems and services are likely to be implemented without a valid assessment of whether they are cost justified lst alone justified in terms of other criteria
CACM	public protection and education with eft research has revealed the existence of widespread misinformation and lack of knowledge about eft among business and government as well as consumers as a result any effort to stimulate meaningful public participation in decisions on the introduction of eft systems will require a coordinated educational effort of considerable scale in addition research has revealed shortcomings in the present system for defining responsibilities liabilities and avenues of recourse this article presents several possible alternatives for improving the current system but ongoing research is also needed to assure that actions taken will be responsive to the changing environment and consumer needs
CACM	vulnerabilities of efts to intentionally caused losses the hypothesis that consumers are provided greater accuracy and freedom from error and fraud with electronic funds transfer systems efts is discussed in light of the technical capabilities and potential of the computer to protect against both accidentally and intentionally caused losses although the nomenclature for business crimes remains the same as for manual depository and other financial service systems   for example fraud theft embezzlement   the characteristics of the crimes are new the changes resulting from the accelerating use of efts and its continual technological advances broaden the scope of security issues to be examined factors such as backup requirements regulatory and legislative actions and economics give rise to the urgency for immediate research into solutions for emerging efts   related vulnerabilities
CACM	policy values and eft research anatomy of a research agenda there is an emerging recognition that eft systems have the potential to vastly alter the payment and fund transfer system in american society a number of forces and actors are involved in this evolution and the values vary significantly depending on individual and institutional perspectives these value conflicts are highlighted in a six part research agenda technological issues in eft eft impacts on people economic impact of eft regulation and control of eft and evaluating and monitoring eft systems
CACM	revised report on the algorithmic language algol 60 the report gives a complete defining description of the international algorithmic language algol 60 this is a language suitable for expressing a large class of numerical processes in a form sufficiently concise for direct automatic translation into the language of programmed automatic computers
CACM	the humble programmer we shall do a much better programming job provided that we approach the task with a full appreciation if its tremendous difficulty provided that we stick to modest and elegant programming languages provided that we respect the intrinsic limitations of the human mind and approach the task as very humble programmers
CACM	go to statement considerd harmful
CACM	certification of algorithm 271 quickersort quickersort compiled and run without correction through the aldep translator for the cdc 1604a comparison of average sorting items with other recently published algorithms demonstrates quickersorts superior performance
CACM	semiotics and programming languages i have based my paper on semiotics and its three dimension i should insert at this point that language has many aspects and that pragmatics semantics and syntactics do not necessary cover all of them one can however project most aspects into the three semiotic dimension and there seems to be a strong tendency to do so today
CACM	an algebraic compiler for the fortran assembly program an algebraic compiler has been written which may be added to the fortran assembly program this compiler will expand all algebraic statements with the following operations addition subtraction multiplication and division it will compile multi level expressions in floating point arithmetic this is easily be revised to fixed point
CACM	correction to economies of scale and the ibm system 360 on page 439 a typical instruction mix id discussed and the timing computed as outlined in that page through an undetected programming error the times and the resulting regression equation are slightly in error
CACM	generating permutations by nested cycling the purpose of this letter is two fold first to give due credit to the tompkins paige algorithm and second to clarify a comment by hill cr review 13891 on programs for permutations
CACM	the lincoln keyboard   a typewriter keyboard designed for computers input flexibility a new typewriter keyboard for direct and punched paper tape computer input will replace the usual commercial keyboard with 88 characters chosen for the convenience of programmers the lincoln keyboard is expected to facilitate the programming of algorithmic process and should allow considerable flexibility in assembly and utility routines
CACM	work is in progress on a formula coding technique allowing direct entry into the computer of formulae typed on an 84 character flexo writer this flexo writer will be modified for automatic half line advance and retract without carriage return to permit completely general sub and superscripting
CACM	a non heuristic program for proving elementary logical theorems the paper discusses problems involved in designing a device capable of distinguishing among speech events that are normally recognized as different by native speakers of a particular language parallels between these problems and those of chemical analysis are pointed out
CACM	reiteration of acm policy toward standardization the periodic change in officers chairman and editors which usually follows as election occasionally results in a change in policy in the case of this department there is no radical change but this is nevertheless the proper time to reiterate ans underline acms policy with respect to standardization in the computer area
CACM	the reactive typewriter program 84 character keyboard including alphabetical upper and lower case for good readability if the machine is restricted to only a single case the lower case is preferred the reactive typewriter should be portable the reactive typewriter should operate over any commercially used dial type telephone voice or telegraph telex line or over leased nondial telegraph lines interchangeably
CACM	structures of standards processing organizations in the computer area in line with the acms policy statement comm acm 5 nov 1962 547 549 the following organizational descriptions have been provided in order to describe standardization activities pertinent to computers and information processing
CACM	microprogramming emulators and programming languages the problem we have been concerned with is that of converting language to action   or intellectual energy to mechanical energy the medium that we use for this purpose is language and therefore we are preoccupied with the subject of language in the areas of language investigation we have concentrated first on formalizing syntax and then on semantics
CACM	algem   an algebraic manipulator algem is a package of subprograms written in slip fortran iv and map 7094 ii to manipulate algebraic expressions algems basic algebraic operations are additions subtractions multiplications division and exponentiation it is capable of handling any number of single letter variables variable exponents and of finding the highest common factor of two polynomials also included are such functions as substitution differentiation determining coefficients of specified variables solving a linear equation basic i o routines plus other special purpose and arithmetic routines the major innovation of algem over other manipulators is the assignment of types to all expressions and the use of a standard ordering procedure
CACM	a formac program for the solution of linear boundary and initial value problems a computer program is described which has been developed for obtaining approximate solutions to linear initial and boundary value problems involving differential equations for each problem input to the program includes 1 the equations in symbolic form to be satisfied   the differential equations equations describing auxiliary conditions such as boundary conditions etc 2 a numerical description of the regions in which each of the equations are to be satisfied 3 sets of functions in symbolic form to be used in linear combinations to approximate the solution functions give the above input the program generates an approximation to the solutions of the specified problemm in terms of the specified functions which is optimum in the least squares sense
CACM	symbolic manipulation of poisson series poisson series of three variables are manageable symbolically through as a set of formal subroutines written partially in the ibm 7094 machine language but to be called in the fortran language for use in fortran programs an effort has been made to supply those operations which are most required by celestial mechanics the routines are entirely self contained subroutines and require only standard fortran input output units 5 and 6 they are design to avoid waste and overflow of core storage space
CACM	manip a computer system for algebra and analytic differentiation a mathematical expression to be operated upon is written in fortran like notation and stored in the computer as a string of bcd characters with all blanks removed it may be as complicated as desired parentheses nested without restriction etc so long as the entire expression or any subsequent form does not exceed 5000 characters the problemm of performing algebraic operations and obtaining analytic derivatives was translated into that of identifying and manipulating character sequences programs which resulted were written in fortran iv for a cdc 3600 and are discussed in detail
CACM	grad assistant   a program for symbolic algebraic manipulation and differentiation the general recursive algebra and differentiation assistant grad assistant now under development is a set of lisp functions which symbolically manipulate abd differentiate algebraic expressions it is designed for use with problemms in which a large amount of routine manipulation is to be done by a program without human intervention thus grad must recognize necessary simplifications without external guidance while some complicated expressions notably ones involving nested radicals and trigonometric functions do not yield completely to the present version it has proved quite useful indeed
CACM	an on line program for non numerical algebra the goal of this program is to make a step toward te design of an automated mathematical assistant some requirements for such a program are it must be easy to access and that the result must be obtained in a reasonably short time accordingly the program is written for a time shared computer the q 32 computer as system development corporation santa monica california was chosen because it also had a lisp 1 5 compiler programming and debugging was done from a remote teletype console at stanford university
MED	correlation between maternal and fetal plasma levels of glucose and free fatty acids correlation coefficients have been determined between the levels of glucose and ffa in maternal and fetal plasma collected at delivery significant correlations were obtained between the maternal and fetal glucose levels and the maternal and fetal ffa levels from the size of the correlation coefficients and the slopes of regression lines it appears that the fetal plasma glucose level at delivery is very strongly dependent upon the maternal level whereas the fetal ffa level at delivery is only slightly dependent upon the maternal level
MED	changes of the nucleic acid and phospholipid levels of the livers in the course of fetal and postnatal development we have followed the evolution of dna rna and pl in the livers of rat foeti removed between the fifteenth and the twenty first day of gestation and of young rats newly born or at weaning we can observe the following facts 1 dna concentration is 1100 ug p on the 15th day it decreases from the 19th day until it reaches a value of 280 ug 5 days after weaning 2 rna concentration is 1400 ug p on the 15th day and decreases to 820 during the same period 3 pl concentration is low on the 15th day and during foetal life 700 ug and increases abruptly at birth 4 the ratios rna cyto dna and pl cyto dna increase regularly from the 18th day of foetal life 5 nuclear rna and pl contents are very high throughout the development 6 these results enable us to characterize three stages in the development of the rat liver   from the 15th day to the 18th day of foetal life stage of growth through hyperplasia without hypertrophy   from the 19th day of foetal life to the 3rd day of post natal life stage of cellular reorganisation   after the 3rd day of post natal life stage of growth through hyperplasia and hypertrophy
MED	surfactant in fetal lamb tracheal fluid lambs delivered by cesarean section with intact fetal circulation have a fluid filling the trachea analysis revealed that this fluid contained material high in surface activity in lambs delivered near term but less surface activity in premature lambs administration of 10 per cent oxygen to the ewe for 1 hour prior to delivery did not alter the surfactant properties of the fetal tracheal fluid two analyses of the fetal tracheal fluid revealed it to contain 146 and 198 mg of lipid per 100 ml 30 to 40 per cent of which was phospholipid part of the active component of surfactant the investigations reported here offer a model for further research into possible intrauterine factors in the pathogenesis of hyaline membrane disease
MED	placental and cord blood lipids comparison in a set of double ovum twins a stillborn and a live born 1 determinations of phospholipid total and free cholesterol triglyceride and nefa have been made on placental tissue and cord blood in a set of double ovum twins one stillborn and one live born 2 similarities occurred in all fractions studied except the cord blood triglyceride and nefa levels 3 the serum of the stillborn infant contained one third as much triglyceride and 21 2 times as much nefa as did the live born infant 4 the phospholipid content and the total lipid content of the stillbirth placenta were the highest studied in this laboratory which includes determinations on 26 live births 5 the suggestion is made that increased lipoprotein lipase activity in the cord blood may accompany intrauterine fetal death
MED	free fatty acid concentration in maternal plasma and fetal body fat content subcutaneous injection of 200 u s p units of heparin into female sprague dawley rats produced large and sustained elevations of plasma free fatty acids but no significant change in blood glucose a group of pregnant rats received such injections of heparin 3 times daily throughout pregnancy the fetuses from mothers of this group at 191 2 and 211 2 days of gestation had significantly more body fat than the fetuses from uninjected mothers the hypothesis is presented that the maternal free fatty acid concentration in part determines fetal fat accumulation it is proposed that the body composition changes noted in babies of mothers with diabetes might thus be ascribed to abnormally high maternal plasma free fatty acid concentrations
MED	the concentration of non esterified fatty acids in maternal and fetal plasma in intact alloxan diabetic and x ray irradiated rats determinations of the non esterified fatty acids in the plasma of pregnant rats showed that there do not exist any increases in the concentrations depending on pregnancy during the period from the 20th   22nd day of pregnancy in the fetal plasma the concentrations of non esterified fatty acids only amounted to 40   50 per cent of the maternal values with alloxan diabetes produced 2 days prior to the test the concentration in the maternal plasma increased three  to fivefold while at the same time a significant rise was absent in fetal plasma with slightly increased average values whole body x ray exposures dose 400r dose output 40r min of non pregnant female and of pregnant rats beginning on the 17th day of pregnancy did not result in any changes of the concentration of non esterified fatty acids immediately after irradiation
MED	lipid metabolism in toxemia and normal pregnancy the amount and fatty acid composition of total lipid extract from serum were examined in normal pregnant women in the first second and third trimesters and early postpartum period and in patients with mild and severe preeclampsia and with essential hypertension placentas at term were also examined for total lipid and its fatty acid composition in the normal women total serum lipid increased during pregnancy the rise was less pronounced in those with preeclampsia or hypertension serum palmitate was mildly but significantly elevated in preeclampsia total lipid and arachidonic acid were elevated in the placentas of preeclamptic women the findings are compared with those obtained from animals developing eclampsia on an experimental basis
MED	essential fatty acids and acids with trans configuration in the subcutaneous and visceral fat of the newborn we made an investigation of the subcutaneous and visceral fat in the newborn we estimated the contents of linolic and linolenic acid and of acids with trans configuration spectrophotometrically we were able to show the penetration of these acids through the placental barrier the essential fatty acid contents of fat in the newborn is low in immature ones about 7 14 g there is a rising trend
MED	acetoacetate formation by livers from human fetuses aged 8 17 weeks slices and homogenates from livers of human fetuses aged 8 17 weeks have a low rate of acetoacetate formation which can be raised by addition of acetate or octanoate to the incubation medium it was not possible to demonstrate acetoacetate formation by isolated liver mitochondria from 17 week old fetuses probably because mitochondria are injured during isolation
MED	changes in blood glucose and non esterified fatty acids in the foetal and newborn lamb after injection of adrenaline changes in blood glucose and non esterified fatty acids after intravenous adrenaline were measured in foetal newborn and adult sheep in the foetus and immediately after birth there was very little increase in either blood glucose or non esterified fatty acids after adrenaline the response of blood glucose to adrenaline had reached adult levels at twenty four hours of age the response of non esterifi  ed fatty acids to adrenaline increased gradually over the first week
MED	electron microscopic observatations on transference of fat through the human placenta from the results of our previous and present studied on the transportation of fat through the human placenta by means of electron microscopy we obtained the following conclusions 1 neutral fat can permeate through the human placenta without dissociation 2 almost all processes of fat permeation seem to be due to the biological activity pinocytosis is most representative but the authors newly found several facts such as dissolution like change in the basement membrane and transport via the stroma cell the authors believe that these results will bring a clue to explain the mechanism of biological transportation of materials through the placenta
MED	the content of phosphatides triglycerides and cholesterol in placentas maternal fetal and new born liver of the white rat thin layer chromatographic examinations in the maternal rat liver showed different rise of the triglycerides and a significant increase of the esterified cholesterol however no striking changes in the content of free cholesterol and lipid phosphorus with the fractions examined lecithin colamine cephalin sphingomyelin and lysolecithin as compared to the liver of adult rats the fetal liver contains a little less than 50 per cent lipid phosphorus the difference is conditioned by the concentrations of lecithin and colamine cephalin on the 19th day the content of triglycerides is lower than in the mother rat referred to the dry weight there results a decrease of all phosphatide fractions as well as of the free cholesterol and a slight rise of the triglycerides from the 19th to the 22nd day the rise of the phosphatide concentrations to the values of adult rats occurs immediately after birth under the influence of milk food which moreover leads to a considerable increase of the triglyceride values phospholipid  and triglyceride concentrations of the placenta correspond to those of the fetal liver solely the content of free cholesterol is higher at the end of pregnancy the content of triglyceride drops towards the 22nd day
MED	analysis of mammalian lens proteins by electrophoresis lens proteins of different mammalian species were analyzed by two dimensional starch gel electrophoresis the number of fractions detected by this means varied from 11 20 a crystallin was resolved into two to three components b crystallin into 5 11 and y crystallin into three to five components this technique provides a sensitive method for the fractionation of lens proteins and for analyzing species differences
MED	an autoradiographic study on cell migration in the eye lens epithelium from normal and alloxan diabetic rats lenses from normal and alloxan diabetic rats with and without cataract were investigated by autoradiography 4 hours 4 days and 8 days after an intraperitoneal injection of h3 thymidine 0 4 uc g body weight the rats were made diabetic 8 days prior to the injection of thymidine at an age of 4 weeks the position of labelled nuclei of the lens epithelium was noted and their grain numbers counted the diabetic rats had a lower frequency of labelled nuclei than the controls but after 4 hours their grain counts were equal frequency diagrams of labelled nuclei are given for each of the three experimental periods a predominant peak appears after 4 hours at a distance of 30 60 cells in front of the beginning of the nuclear arc a successive shift towards this area was observed for the longer experimental periods the shift of the peaks was more restricted in the diabetic animals this result may best be interpreted as an effect of an increased time of cell generation as an appendix a histotechnique for the eye lens is given in collaboration with mrs gertraude moewis
MED	lens development the differentiation of embryonic chick lens epithelial cells in vitro and in vivo the behavior of lens epithelial cells from six day chick embryos was studied in three different experimental situations a explantation into several different fluid culture media b explantation followed by reimplantation into lensectomized embryonic eyes and c explantation followed by reimplantation into the embryonic coelomic cavity specimens were examined histologically and the total volume of the lens material of each specimen was determined from the planimetry of serial sections the results were interpreted as follows 1 with a small amount of protein supplement in the culture medium embryonic lens epithelial cells are capable of a limited amount of independent cytodifferentiation without protein supplement they fail to undergo any fiber formation 2 when returned to the eye environment cultured epithelial explants will respond with a resumption of growth with further cellular differentiation and with at least some of the morphogenetic changes necessary to form a lens the embryonic coelom will not support these responses 3 the initiation of the formation of lens fibers is not sufficient for their complete autonomous maturation 4 the internal architecture of the developing lens is not the only determinant of its overall shape
MED	treatment of active chronic hepatitis and lupoid hepatitis with 6 mercaptopurine and azothioprine 6 mercaptopurine or azothioprine imuran was used successfully in 3 patients with active chronic hepatitis and 2 with lupoid hepatitis for periods up to 1 year these drugs allowed modification and even abolition of discomforting corticosteroid regimes their action in chronic hepatitis may be analogous to their anti immune action in suppressing homograft rejection
MED	treatment of collagen diseases with cytostatics 22 patients with collagen diseases and 3 patients with other immunological diseases were treated with the cytostatic antimetabolites purinethol 6 mercaptopurine and imuran azathioprine for an average period of four months range one to eleven months improvement was obtained in 17 patients and in 20 out of 22 patients who had been on long term glucocorticoid medication the steroid therapy could be permanently discontinued serious complications occurred in the form of two deaths from pancytopenia and sepsis the treatment requires careful supervision of the patients and should only be instituted on strict indications when the alternative is long term glucocorticoid medication
MED	bilateral popliteal cysts in a patient with rheumatoid arthritis a case of bilateral popliteal cysts and multiple joint subluxations in a patient with rheumatoid arthritis on corticosteroid medication for many years is reported the effect of long term corticosteroid therapy on all periarticular connective tissue structure and the relationship of articular disease and popliteal knee cysts to this therapy have been discussed
MED	systemic lupus erythematosus and renal transplantation report of two cases two cases of systemic lupus erythematosus along with terminal uremia secondary to lupus nephritis are presented both patients were treated with renal hemodialysis and transplantation certain mechanical infectious and immunologic problems were responsible for their death there was no evidence of resurgence of lupus erythematosus in either patient and the transplanted kidneys did not show evidence of lupus nephritis renal transplantation should be considered as a last resort in treatment of patients with terminal lupus nephritis
MED	arteritis and localised periosteal new bone formation 1 three patients with localised periosteal new bone formation associated with periosteal arteritis and other evidence of systemic lupus erythematosus are described 2 systemic steroid therapy was valuable in the management of this condition
MED	fine structure of subtilis phage sp 50 some structural details and anomalous forms of subtilis phage sp 50 are described
MED	genetic transcription during morphogenesis messenger rnas from bacillus subtilis undergoing sporulation germination or step down transition have been characterized and compared hybrid competition experiments indicate that these messengers are derived from distinct genetic loci the results are consistent with the hypothesis that differential transcription of the genome occurs during morphogenesis the data also complement previously observed changes in morphology and enzymatic activity in sporulating bacteria
MED	renal amyloidosis a clinicopathological study the clinical and histopathological data from 40 cases of renal amyloidosis diagnosed by percutaneous renal biopsy are presented twenty two cases were labelled as secondary amyloidosis as definite aetiological factors responsible for renal amyloidosis could be discovered the predisposing disease states leading to amyloid deposits in the kidney in the order of frequency were fibrocaseous pulmonary tuberculosis bronchiectasis lung abscess and ileocaecal tuberculosis five cases were labelled as suspected primary amyloidosis as a definite evidence of the predisposing disease could not be obtained although the skiagram of chest revealed minimal healed foci no cause could be determined in thirteen cases which were therefore labelled as primary amyloidosis albuminuria was a constant feature in all the cases and 32 cases presented as nephrotic syndrome the rest of the cases presented with hypertension or renal failure in addition to albuminuria the ancillary procedure viz congo red test gingival and liver biopsies proved to be of limited value in the diagnosis of renal amyloidosis the importance of percutaneous renal biopsy as a diagnostic tool has been emphasised
MED	idiopathic autoimmune hemolytic anemia and idiopathic thrombocytopenic purpura associated with diffuse hypergammaglobulinemia amyloidosis hypoalbuminemia and plasmacytosis a case is reported of a sixty nine year old woman with severe idiopathic autoimmune hemolytic anemia which was initially controlled by splenectomy a relapse associated with the development of severe autoimmune thrombocytopenic purpura failed to respond to large doses of prednisone but was controlled to a variable degree with imuran associated features included diffuse hypergammaglobulinemia excessive gamma u proteins in the urine idiopathic hypoalbuminemia with a greatly reduced total exchangeable albumin pool amyloidosis in the spleen and other organs and diffuse plasmacytosis of the bone marrow lymph nodes and thoracic and peritoneal fat these features and their interrelationships are discussed there was no deficiency in the synthesis of specific neutralizing antibodies against viruses indicating that a qualitative immune deficiency did not exist the frequency of occurrence of thrombocytopenic purpura in such a case is discussed as is the prognosis the mechanism of action of antimetabolites in inducing a remission in autoimmune hemolytic anemia as well as the etiology of the disease is reviewed
MED	corticosteroid therapy of amyloid nephrotic syndrome the results of treatment with prolonged adrenal corticosteroids in 26 adults with amyloid nephrotic syndrome are presented eight subjects were observed in this series and 18 additional cases were summarized from the literature twenty two of the patients were male and four were female the diagnosis was established by renal biopsy in 19 instances and by autopsy in the others with 18 patients considered to have primary amyloidosis and 8 secondary amyloidosis the majority of the subjects died in renal failure with an average survival after onset of the disease of 17 6 months the renal disease was indistinguishable from that seen in other forms of the nephrotic syndrome with the possible exceptions of a a high incidence of purpuric skin lesions b a low or negligible incidence of hypertension at times actual hypotension was prominent and c a rapid and inexorable progression of azotemia despite persistence of the clinical and biochemical characteristics of the nephrotic syndrome amyloidosis was found by percutaneous renal biopsy in 12 per cent of 83 adults with the nephotic syndrome corticosteroids did not appear to affect the progress of the disease and were neither beneficial nor detrimental in view of the high incidence of deleterious side effects of prolonged corticosteroid therapy and the availability of potent diuretic agents which may be helpful in relieving edema in this disorder it is felt that corticosteroids are contraindicated in the treatment of amyloid nephrotic syndrome
MED	renal amyloidosis a biopsy study the relationship of the amount of amyloid deposition in the kidney to the clinical picture is reviewed in 14 cases of renal amyloidosis diagnosed by renal biopsy the large percentage of patients who had the nephrotic syndrome 11 patients probably reflects the criteria for renal biopsy at this institution the etiology of the amyloid deposition did not seem to be clearly correlated with either the amount of amyloid deposition in the kidney or the severity of the clinical renal disease all patients had deposits in the glomerulus and the heavier the deposition the severer the renal disease of 7 patients who had biopsy of the bone marrow all had abnormal types or numbers of plasma cells the age range in primary amyloidosis appeared to be about the same as that in amyloidosis secondary to myeloma amyloidosis should be suspected in patients with proteinuria the nephrotic syndrome or renal failure
MED	amyloid goitre a case report a case of amyloid goitre in an indian female aged 27 years occurring as a sequelae to pulmonary tuberculosis is reported
MED	amyloid starch gel electrophoretic analysis of some proteins extracted from amyloid proteins extracted by strong urea from washed tissue of patients with amyloidosis secondary to several diseases or associated with familial mediterranean fever have common major electrophoretic components in hearts of primary amyloidosis one component in common with the secondary amyloid may be present however primary amyloid is much more difficult to dissolve and does not regularly give the components observed when the secondary amyloid is extracted the big question remains as to what constituent or constituents comprise the fibrils now known to be a part of amyloid
MED	selectivity of protein excretion in patients with the nephrotic syndrome with a gel diffusion precipitin technique and commercially prepared antisera urine plasma ratios of specific proteins were determined individual protein clearances expressed as a percentage of transferrin clearance were plotted as ordinates against respective molecular weights on a log log graph a straight line was evident graphically its constants were estimated by the method of least squares and the slope expressed as was determined the slope of the line may be said to express the degree of glomerular selectivity to protein excretion sixty five determinations were performed in 48 patients 45 satisfying the usual criteria of the nephrotic syndrome 1 those patients with primary renal disease and the nephrotic syndrome who displayed high selectivity types of proteinuria greater than the average for the group 1 sd usually respond initially to steroid therapy regardless of the acute or subacute glomerular changes observed on renal biopsy 2 those patients with chronic renal disease and the nephrotic syndrome display an average and frequently a low selectivity type of proteinuria 3 there appears to be no characteristic type of selectivity for a given pathologic group of patients with the nephrotic syndrome 4 the degree of selective protein excretion is not related to the total daily amount of protein being excreted at any one time and remains fairly constant despite fluctuation in the amount of protein being excreted 5 there is a slight correlation of borderline significance between the degree of selective protein excretion and the duration of the disease and the initial para aminohippuric acid clearance 6 a statistically significant correlation exists between the initial blood urea nitrogen or inulin clearance and the selectivity type of protein excretion those patients who were not azotemic and had initially near normal inulin clearances had an average selectivity type or better 7 it is suggested that if the adult patient is initially azotemic and has a grossly abnormal inulin clearance response to therapy is unlikely whereas if the blood urea nitrogen is normal and the inulin clearance is near normal response to therapy cannot be predicted with any degree of accuracy further studies of adult patients with the nephrotic syndrome are required to substantiate this premise
MED	some aspects of haemostasis after open heart surgery synopsis in two groups of patients undergoing extracorporeal circulation with hypothermia changes were found in the coagulation mechanism which were probably due to the dosage of polybrene administered the role of heparin and polybrene and the concept of activation of the coagulation mechanism in the production of bleeding after perfusion are discussed
MED	a case of interventricular septal defect with dextrocardia and situs inversus treated by surgery a case of interventricular septal defect associated with situs inversus and dextrocardia in twenty year old male patient was presented along with discussion on three types of dextrocardial complexes and with emphasis on the rarity of occurrence of the intracardiac anomalies in true mirror image dextrocardia with total situs inversus a comment was also made on kartageners syndrome which was excluded by appropriate radiographic procedures in this case the closure of the interventricular septal defect with extracorporeal circulation was successfully performed under moderate hypothermia
MED	excretion patterns of urinary metabolites of estradiol 4 c14 in postmenopausal women with benign and malignant disease of the breast a study of the excretion patterns of the urinary metabolites of estradiol 4 c1j administered to a group of 43 postmenopausal women 38 with advanced mammary carcinoma prior to endocrine therapy and 5 with benign mammary dysplasia is reported a chromatographic method was employed for the determination of estradiol estrone and estriol and other estrogen metabolites the urinary excretion pattern is defined by a the extent of excretion of isotope in each of 3 successive 24 hr collection periods b the percentage of the urinary radiometabolites enzymatically hydrolyzed c the relative concentration of the several metabolites in the hydrolyzed fraction wide subject to subject variations were found the metabolites other than estradiol estrone and estriol comprised a large portion of the total estrogens excreted a significantly lower amount of estradiol was noted in the group of women with mammary carcinoma as compared to the amount found in the group of women with benign mammary dysplasia suggesting that the former group metabolizes more rapidly the administered estradiol although the excretion patterns of patients who failed to respond to estrogen treatment nonresponders differed the greatest from the patterns associated with benign disease distinctive patterns of the urinary excretion of isotopic estrogens which allowed a statistically significant or clinically useful separation between responders and nonresponders to subsequent estrogen therapy were not discovered
MED	the localizing significance of limited simultaneous visual form perception a patient presenting with an isolated spelling dyslexia and impairment in picture interpretation simultanagnosia was shown by tachistoscopic studies to have a pathological limitation of simultaneous form perception at autopsy a localized lesion was found within the inferior part of the left occipital lobe these findings are discussed in relation to the problem of the disorder of function underlying agnosic alexia
MED	visual anosognosia in cortical blindness antons symptom denial of blindness in a case of bilateral hemianopia is presented to acquaint ophthalmologists with this symptom which is well known to neurologists but is rarely seen by opthalmologists
MED	the development of social attachments in infancy this report is devoted to the formation and development of social attachments in infancy it is suggested that the core of the attachment function is represented by the tendency of the young to seek the proximity of certain other members of the species and that the most suitable operational definition may be found in the behavior of the individual when deprived of such proximity the study takes the form of a longitudinal follow up in which 60 infants were investigated at four weekly intervals from the early weeks on up to the end of the first year and again at 18 months of age with the use of an attachment scale based on seven everyday separation situations the following three main parameters were explored the age at onset of specific attachments the intensity of such attachments and the number of objects to whom attachments are formed a measure of fear of strangers was also included results indicate that the age at onset of specific attachments is generally to be found in the third quarter of the first year but that this is preceded by a phase of indiscriminate attachment behavior that the intensity of specific attachment increases most in the first month following onset and that thereafter fluctuations occur in individual cases which make long term prediction difficult and that multiplicity of objects can be found in some instances at the very beginning of the specific attachment phase becoming the rule in most of the remaining cases very soon thereafter correlations between the attachment variables as well as with the fear of strangers measure are presented and an examination is also made of the conditions eliciting protest at proximity loss of the manner in which protest is expressed and of the conditions necessary to terminate protest individual differences with regard to the three main parameters were explored in a subgroup of 36 infants a number of variables were examined in relation to these individual differences and suggestions made regarding the conditions which affect the manifestation of the attachment function the data are discussed in relation to four themes which emerged from the findings the nature of the attachment function its developmental origins its developmental trends and the influence of the social setting
MED	separation anxiety as a cause of early emotional problems in children in summary three cases of disturbed behavior in children have been discussed with particular emphasis on disturbances in feeding sleeping and motility some of the hypotheses have been presented of why such behavior should develop the significance of attachment behavior and separation anxiety in infants has been particularly stressed difficulties in mothering care are threatening to the childs sense of security and lead to greater experience of separation anxiety which may then be reflected in various disturbances or alterations in his behavior this experience of separation anxiety is the result of early life experience may reach pathologic proportions and may account for many later problems in children and adults
MED	the production of malignant tumours by nickel in the rat powdered metallic nickel when injected intramuscularly into rats produced tumours of striated muscle origin most of which were very well differentiated
MED	studies of nickel carcinogenesis fractionations of nickel in ultracentrifugal supernatants of lung and liver by means of dextran gel chromatography chromatographic fractionations have been performed on the ultracentrifugal supernatants of homogenates of rat lung and liver by the use of columns of dextran gel sephadex g 100 a major proportion of nickel in these tissue supernatants has been demonstrated to be firmly bound to macromolecular constituents following acute and chronic inhalation of carcinogenic levels of nickel carbonyl the predominant increases in the concentrations of nickel have been observed in the macromolecular fractions these findings are consistent with the previous demonstration of nickel in purified preparations of ribonucleic acids rna from several rat tissues and with the observation of increased concentrations of nickel in high molecular weight rna from lung and liver following the inhalation of nickel carbonyl
MED	a study of the inhibitory effect of ethylenediaminetetra acetic acid on the thrombin fibrinogen reaction 1 ethylenediaminetetra acetic acid reversibly inhibits the thrombin fibrinogen reaction by means of a time dependent diminution in fibrinogen reactivity 2 this alteration of fibrinogen is due to some property of the edta molecule in an unchelated form and is not due to the removal of trace metal ions 3 possible explanations for this phenomenon are discussed
MED	intradermal test using cobalt chloride selected groups of patients with cobalt allergy and nickel allergy as well as normal controls were tested intradermally with cobalt chloride in the dilutions 10 to 10 reactions of the wheal and flare type appear during the first hours and make the 24 hour reading misleading the papular response to cobalt chloride 10 when read 48 to 96 hours after the injection appears to be a reliable test for cobalt allergy patients with combined nickel cobalt allergy were excluded from the study and the question of group reactions is not discussed nickel allergics give a somewhat stronger reaction than controls to the slightly impure cobalt chloride it would be preferable if the degree of purity of the cobalt chloride were ten times greater
MED	measurements of nickel in biological materials by atomic absorption spectrometry an atomic absorption procedure has been developed which facilitates quantitative measurements of nickel in biological materials including urine ribonucleic acids rna and serum proteins the sensitivity of detection of nickel by the atomic absorption spectrometer 0 10 p p m was insufficient to permit direct measurements of nickel in normal urine therefore it was necessary to employ a dimethylglyoxime extraction procedure to concentrate the nickel prior to atomic absorption spectrometry the coefficients of variation of measurements of nickel in urine and human b  globulins were 6 3 and 5 9 per cent respectively the recovery of nickel added to urine averaged 96 per cent with a range from 94 to 97 and the recovery of nickel added to human b globulin averaged 101 per cent with a range from 96 to 104 the mean concentration of nickel in 24 hr collections of urine from 17 normal subjects was 1 8 ug per 100 ml s d 0 8 with a range from 0 4 to 3 1 the mean urinary excretion of nickel was 19 8 ug per 24 hr s d 10 0 with a range from 7 2 to 37 6 the mean concentration of nickel in 5 preparations of ribonucleic acids from ultracentrifugal supernatants of homogenates of rat lung was 48 ug of ni per gm of rna with a range from 34 to 64 the mean concentration of nickel in 5 preparations of rna from ultracentrifugal supernatants of homogenates of rat liver was 29 ug of ni per gm of rna with a range from 21 to 39 measurements of nickel were performed upon fractions of human serum proteins prepared by continuous flow electrophoresis and by cold ethanol precipitation the highest concentrations of nickel were found in preparations of serum b globulins
MED	properties of activity of 5 nucleotidase in human serum and applications in diagnosis the influence of mg ni and l histidine on purified preparations of bone and intestinal alkaline phosphatases and 5 nucleotidase and on various mixtures of these enzymes has been studied the extent to which these findings can be utilized in the quantitative assay of 5 nucleotidase in serum has been evaluated results are presented on the possible utilization of l histodine in the simultaneous evaluation of serum alkaline phosphatase and 5 nucleotidase activity
MED	some 2 iminoselenazolidin 4 ones and related compounds a series of 2 iminoselenazolidin 4 ones selenazolidine 2 4 diones and some 2 alkylidenehydrazones have been synthesised wide range screening for biological activity failed to reveal any compounds of promise
MED	the influence of methemoglobinemia on the lethality of some toxic anions 1 azide the time course and extent of the methemoglobinemia induced by intraperitoneal sodium nitrite and p aminopropiophenone papp have been characterized in female mice the peak methemoglobin formation 34 is achieved in about 40 minutes comparable levels from papp 15 mg kg are achieved more quickly between 5 and 10 minutes but decline more rapidly to normal both nitrite  and papp induced methemoglobinemia afford a significant degree of protection against poisoning by sodium azide when administered in an appropriate time sequence it was not possible under the same circumstances to protect mice against death from fluoride cyanate thiocyanate selenate or borate although some prolongation of survival time was seen after fluoride the formation of the azide methemoglobin complex has been demonstrated within intact mouse red blood cells and small amounts of the complex were identified in vivo in an antidotal situation we think it important that the protective action of methemoglobinemia has been demonstrated to date only against established inhibitors of cytochrome oxidase
MED	selenium as a trace element an account is given of the discovery of selenium by berzelius and gahn the toxic behaviour of large selenium quantities in soils upon vegetation animals and man is surveyed a review is also given of the role of trace amounts of selenium in the prevention of myopathies in animals finally some recent theories on the importance of retinal selenium to vision are mentioned
MED	toxicity of inorganic selenium salts to chick embryos the effects of selenite and selenate treatment by air cell injection on mortality and growth of 14 day chick embryos during a 64 68 hour period were studied the ld for selenite se was about 0 5 ppm based on weight of the egg contents and that for selenate se about 1 8 2 0 ppm growth depression was evident from these treatments but other gross effects were not prominent the treatment of embryos with selenite and sulfate together caused a greater mortality than treatment with selenite alone
MED	lesions of the islets of langerhans during injections of sodium selenite administered intravenously sodium selenite was administered intravenously in rabbits and in dogs repeated injections can lead to the development of a diabetic syndrome in the rabbit the histological examination of the pancreas in the poisoned animals dogs and rabbits has shown the existence of lesions of the islets of langerhans mostly of the b cells which lose their granules partly or completely these changes seem analogous to the ones produced by alloxan these two poisons act at first by inactivating the sh groups which leads to a deficiency to which the b cells are very sensitive
MED	toxicity of sulfur 35 selenium and tellurium to avian embryos continuous internal irradiation of chick embryos with sulfur 35 administered on the 4th or 8th day of incubation produced abnormalities similar to those observed in selenium toxicosis of avian embryos the highest level of sulfur 35 1600 uc injected into eggs containing 4 day embryos produced morphological abnormalities more severe than those produced by the same level of radiosulfur administered to 8 day embryos or by any level of stable selenium tolerated selenium at levels greater than 30 ug killed all the embryos within 24 hours after injection nearly 20 times more tellurium than selenium was required to kill all the embryos within 24 hours no abnormalities were observed in the tellurium injected embryos
MED	the effect of selenium on the upper respiratory passages results are reported of examination of workers exposed to selenium with special reference to chronic changes in the respiratory passages the findings are the same as reported in the literature we emphasize the occurrence of teleangiectasias on the uvula and on the posterior palatinal arcs and on the epiglotis we describe the occurrence of the first poisoning with selenium xyde in this country the poisoning healed within a few days under symptomatic treatment the patient had however to be transferred into another shop owing to frequent symptoms due to toxic effect of selenium we report also on secondary findings in examination of chronic changes and we emphasize particularly the finding of profesional selenium external otitis
MED	the influence of small selenite doses upon the toxic fatty degeneration of the liver sodium selenite 10 ug kg manifests a lipotropic effect after toxication of the rat by tetrachlorocarbon this effect is absent when the selenite dose is increased to 50 ug kg the level of the total lipides of the liver after ethionine toxication is not significantly influenced by 10 ug selenite kg it is increased by 50 ug selenite kg
MED	selenium caused tumours in 10 out of 23 heterozygous rats administered 10 mg na seo per 1 kg food containing 12 protein and surviving for 18 months cancer of the liver with metastases in the lungs along with sarcoma and adenoma was recorded in another series of the yet incompleted experiment the animals were fed higher quantities of protein and selenium toward 14 19 months in three of them sarcoma was noted in two sarcoma of the lymphatic nodes and in one  of the mediastinum it is suggested that the changes caused by selenium compounds are to some extent due to their antagonistic relationship with methionine
MED	blood and bone marrow damage caused by drugs drug side effects on blood and bone marrow are briefly reviewed they embrace a wide variety of symptoms and pathogenetic mechanisms and in recent years study of these effects has made important contributions to our knowledge of the immunology biochemistry and metabolism of the blood cells
MED	hypothermia physiologic effects and clinical application a survey of the background physiologic effects indications technique and complications of hypothermia is presented the application of this technique is straightforward and safe when used at the proper levels with the proper indications
MED	ehrlich ascites tumor cells agglutination the interference exerted by epsilonaminocaproic acid eac and its acetyl derivative eaca the activity of epsilon aminocaproic acid eac and of its acetyl derivative eaca was studied on antigen antibody reactions membrane antigens and immune globulins in vitro eac and eaca do not affect immune globulins but they do alter the membrane antigens of ehrlich ascites tumor cells and inhibit the agglutination reaction induced by a specific antiserum inhibition is only partially due to the antigenic alteration observed and it represents more prominently a direct interference at the level of the antigen antibody reaction the membrane antigen alternations induced by the drugs and by nitrogen mustard were compared taking into account their toxicity eac and eaca were found to be much more active and more specific than nitrogen mustard
MED	study on the behavior of tumor tissue in diffusion chambers against penetrating host cells in tumor resistant rats tumour cells in diffusion chambers which were implanted in tumour resistant rats were only destroyed by penetrating immunized host cells when membrane filters of large pore size were used whereas with filters of small pore size the tumour cells survived and remained virulent
MED	current status of hypothermia moderate hypothermia has been recommended for many and varied conditions today its value is being questioned in the light of controlled groups of patients at the moment its use is justified in certain cardiac and other operations where circulation may be interrupted for short periods in general surgical procedures where massive sudden blood loss may be anticipated in neurosurgical operations where a relaxed brain is required following acute hypoxia such as seen in cardiac arrest and perhaps in the therapy of acute septicemic shock profound hypothermia in association with extracorporeal circulation rests on shakier premises but can be of value in major cardiac operations where asystole is required and in certain neurosurgical procedures where complete interruption of circulation is indicated there is a great hazard in the development of inadvertent or unrecognized hypothermia in the anesthetized patient monitoring of body temperature is an important feature of the care of the patient in the operating theater and in the recovery room
MED	hyperglycemic coronary perfusion effect of hypothermia on myocardial function during cardiopulmonary bypass in a series of 84 animal experiments hyperglycemic perfusion of the heart gave significant protection to the anoxic heart this protection was evaluated by ventricular function and contractile force studies and was observed after aortic occlusion at 37 28 and 10 degrees c metabolic data revealed a considerable myocardial glucose uptake higher coronary ph higher po and lower pco in the glucose perfused groups as compared to controls a hypothesis for the protective effect may be an alteration in metabolic pathway and support of the myocardial enzyme systems associated with high glucose concentration and utilization
MED	specific carcinoembryonic antigens of the human digestive system a wide variety of human adult and fetal tissues were studied by immunodiffusion techniques in agar gel to determine whether they contained the tumor specific antigen s previously found in colonic cancers in the adult tissues it was demonstrated that identical antigens were present in all tested specimens of malignant tumors of the entodermally derived epithelium of the gastro intestinal tract and pancreas but were absent from all other tested adult tissues the common antigenic constituents therefore represent system specific cancer antigens of the human digestive system system specific cancer antigens have not previously been demonstrated in humans experiments with fetal tissues demonstrated that identical antigens were also present in fetal gut liver and pancreas between 2 and 6 months of gestation these components were named carcinoembryonic antigens of the human digestive system on the basis of the present findings and the recent work regarding control of the expression of genetic potentialities in various genetic potentialities in various types of cells it was concluded that the carcinoembryonic antigens represent cellular constituents which are repressed during the course of differentiation of the normal digestive system epithelium and reappear in the corresponding malignant cells by a process of derepressive dedifferentiation
MED	the course of influenza virus infection in mice organ tissues of infected mice tested by electron microscope using the electron microscope the presence of inclusions could be shown in the lungs and liver of mice infected with the pr 8 strain the inclusions contained particles of size and shape closely resembling the most frequently seen forms of influenza virus the presence of inclusions in liver tissue might perhaps speak for the possibility of virus multiplication in this organ
MED	comparative bone marrow study using two aspiration needles and two biopsy sites bone marrow aspiration is now widely used in the diagnosis of hematologic diseases and many conditions not primarily affecting the blood system a number of techniques have been devised by which a suitable specimen of marrow can be obtained with relatively little discomfort to the patient the two needle sets described in this paper have been found to be equally reliable in obtaining bone marrow for microscopic study and diagnosis comparative studies of bone marrow aspirated simultaneously from the iliac crest and the sternum in 26 patients show no significant difference however there were four instances of dry tap at the iliac site this fact in addition to the observation that less discomfort was experienced by the patient when the sternum was used might indicate that the sternal area is a more reliable and efficient site for obtaining bone marrow it was also observed during this study that patients experienced less discomfort when the university of illinois needle was used the major objection to the use of this needle is the inability to obtain a bone core for biopsy
MED	cell populations in the bone marrow of the normal guinea pig quantitative data have been obtained for cell populations in the bone marrow of the normal 400g guinea pig based on a study of 25 animals there was good agreement between two independent groups of observations and an average of 1880000 nucleated cells per c mm was found of this total 27 were lymphocytes 31 granulocyte precursors and 26 nucleated erythrocyte precursors whole body populations have been computed and the implications of the findings discussed
MED	pneumocystis carinii pneumonia case studies with electron microscopy this paper deals with the clinicopathologic findings in 2 patients with pneumocystis carinii pneumonia the first example was in a 51 2 month old white female infant without an underlying disease the second occurred in association with cytomegalic inclusion disease of the lungs in a 46 year old white woman who had received steroid therapy cytotoxic agents and irradiation to the thorax for hodgkins disease an electron microscope was used for the study of the morphology of the organisms in tissue removed at autopsy
MED	the effect of dehydroepiandrosterone on the dehydroxycorticosteroids in the plasms in various stages of breast cancer and mastopathy the depressing effect of dehydroepiandrosterone on plasma corticosteroids is on an average shortened in advanced breast cancer stage iv the lowest corticosteroid values have been found with the three groups of patients 6 hours after infusion of dehydroepiandrosterone phosphate the effect of dehydroepiandrosterone being still provable after 12 hours with the group suffering from mastopathy the breast cancer group of stage iv had at this time already reached the level of the initial values the breast cancer group of stage iv had at this time already reached the level of the initial values the breast cancer group of stage i ii behaved intermediately the less lasting effect of dehydroepiandrosterone is attributed to its accelerated transformation in advanced breast cancer
MED	the meaning of ph at low temperatures during extra corporeal circulation a review of the temperature gradients occurring during profound hypothermia is made in regard to acid base changes in general and to ph readings in particular it is concluded that terms such as body mean average and core temperature should be discarded and that when a temperature is quoted it should be referred to the site at which it was measured the main circumstances in which blood ph is measured at a temperature different from that at which the blood is equilibrated with respiratory gases are reviewed by describing the changes which occur during tonometry experiments in this way fundamental changes can be understood before considering the more complicated sequences of events taking place in the living body the alterations that occur in the concentrations of protein and bicarbonate ion when whole blood is cooled are reviewed together with their influence on correction factors the reasons why these factors should not be applied to blood when the living body is undergoing hypothermia involving the use of an extra corporeal circulation are discussed examples of the numerical values for blood ph during the two main methods for producing profound hypothermia one using autogenous lung perfusion and the other a pump oxygenator are given with reference to the influence of pco2 upon these values the existing methods of acid base measurement appear to be sufficiently accurate to reflect the metabolic component during profound hypothermia
MED	induced tumour resistance in rats the human sarcoma hs has been grown in weanling rats treated with cortisone this growth was modified by prior injection of various tissue antigens active immunity was produced by using human placenta or embryonic tissue as antigen and similar results were obtained using suspensions of rapidly growing human tumours the response to other human tissues varied foetal muscle and spleen were active whereas adult plasma was inactive except from some patients with extensive malignant disease passive protection was produced by using certain human sera at the time of challenging with hs sera from five women who aborted showed this characteristic where the pregnancy continued to term antisubstances were not found and they were present in the puerperium in only two out of fifty cases further groups of rats were given rat embryonic tissues as antigen and the tumour challenge was then made with walker tumour the results were variable with a benzpyrene induced tumour in a pure line of wag rat the effect was not obtained except in isolated cases in experiments in mice using as challenge an irondextran induced mouse sarcoma prior injection with embryonic mouse liver or placenta increased the resistance to the growth of the tumour but the tumour has not as yet been produced in a pure line mouse on the other hand mouse experiments using as challenge the crocker tumour proved negative it is suggested that immune reactions may play a part in causing some abortions
MED	urinary steroid estimations in the prediction of response to adrenalectomy or hypophysectomy a clinical trial has been carried out to test the use of the discriminant in assessing the suitability of patients with advanced breast cancer for hypophysectomy or adrenalectomy patients with positive discriminants submitted to hypophysectomy have a much better prognosis than patients with negative discriminants submitted to adrenalectomy patients selected for adrenalectomy because of negative discriminants have a significantly worse response to the operation than patients selected by random sample patients selected for hypophysectomy because of positive discriminants tend to have a better response to the operation than do patients selected by random sample but the difference is not significant adrenalectomy is not recommended for patients with negative discriminants
MED	primary epidermoid cancer of the lung ultrastructural study the early epidermoidic epithelioma of the human lung are initiated by the proliferation of body cells whose structure is analogical to that of the medium cells and or the modificated basal cells of the normal bronchial wall the presence of desmosomes and tonofibrils in the cells of the stratum germinativum of the bronchial epithelium and in the cells derived from it allows us a better understanding of the malpighian metaplasis of this wall and gives account of the epidermoidic evolution of the bronchial epithelioma certain nuclear and cytoplasmic modifications suggest the possibility of a causal virus
MED	biosynthesis of glycoproteins i incorporation of glucosamine  c into liver and plasma proteins of the rat it has been shown that glucosamine 1  c administered intravenously to fed rats is rapidly removed from the blood stream and appears first as trichloroacetic acid soluble derivatives in the tissues this is followed by a conversion to macromolecules at least 80 of the administered compound can be recovered in tissues the liver is by far the most active organ in accumulating glucosamine this is rapidly converted to protein bound components of the liver particulate fraction microsomes and mitochondria and is then released to the plasma without appreciable accumulation in the soluble proteins of the liver it is concluded that the glucosamine is transferred to the peptide chains of glycoproteins at some stage before these proteins are released from the liver particulate fraction
MED	acute experimental pneumococcal type i pneumonia in the mouse the migration of leucocytes from the pulmonary capillaries into the alveolar spaces as revealed by the electron microscope in this preliminary study of experimental pneumococcal pulmonary pneumonia in the mouse the leucocytes were observed to pass from the capillaries into the interstitial tissue and eventually into the alveolar spaces through the intercellular junctions of the endothelial and epithelial cell membranes
MED	a light and electron microscope study of developing respiratory tissue in the rat 1 light microscopic observations on the development of the rat lung have shown the presence of glandular canalicular and alveolar stages 2 these same three stages can be identified by electron microscopy and all may be present in different parts of the lung at one time e g at 40 and 45 mm c r length 3 in the glandular stage the lung tissue itself has an immature appearance by light microscopy and by electron microscopy individual cells also are immature in respect of organelles glycogen is present in immature cells 4 during the canalicular stage lung tissue becomes more vascular 5 throughout all stages of development the duct or air spaces are always lined by a continuous and complete epithelium and blood vessels by a complete endothelium 6 lamellated inclusion bodies are present in epithelial endodermal cells at an early stage of development 7 micropinocytotic vesicles are present in large numbers in both epithelial and endothelial cytoplasm and it is suggested that in the foetus they may indicate absorption of amniotic fluid from alveolar spaces 8 the mechanism of alveolar distension is discussed and its nature remains uncertain 9 respiratory tissue of the rat is not fully differentiated at birth and the importance of this fact in human infants is discussed 10 the adult blood air barrier consisting of epithelium zona diffusa and endothelium varies in thickness this project was performed whilst both of us were in receipt of grants from the medical research council of canada for which gratitude is expressed our gratitude is also expressed to miss sylvia smith for typing the manuscript
MED	the pathogenesis of viral influenzal pneumonia in mice the pathogenesis of influenzal pneumonia in mice was studied by electron microscopy mice were inoculated with 1 5 ld of pr8 influenza virus and killed at varying intervals after inoculation observations by light microscopy were correlated with those by electron microscopy in order to evaluate the lesions produced at the periphery the earliest lesions were focal areas of edema of alveolar lining cells the capillary endothelium and the interposed basement membrane this caused an appreciable thickening of the blood air pathway hypertrophy degeneration and desquamation of the alveolar lining and proliferation of alveolar macrophages resulted in complete consolidation which was progressive up to 1 week after infection the central areas of the lung were affected somewhat differently at 3 days after infection the nonciliated bronchiolar cells showed considerable hyperplasia of endoplasmic reticulum and apical cytoplasmic edema viral particles matured at the lumen surface of these cells and were then released into the bronchiolar lumen the bronchiolar cells both ciliated and nonciliated underwent degeneration and sloughed into the bronchiolar lumen the regenerating epithelium was stratified and the surface cells were elongated and flattened the peribronchiolar interstitial tissue gradually became totally infiltrated by cells mostly of the mononuclear type
MED	studies on aging with horse crystalline lens gel as a contribution to biomorphosis of the mammalian crystalline lens the effects of biomorphosis  dash the continuous material change in the chemical composition of the organs and tissues  dash are studied on the horse crystalline lens in respect of its amino acid content subject to substantial variations in the course of life it is shown by electrophoretic and paperchromatographic methods that the qualitative composition of horse crystalline lenses remains quite the same but that within the individual age stages there occur quantitative variations between the individual amino acids
MED	the role of alveolar inclusion bodies in the developing lung the developing alveolar epithelium of man and rat contains characteristic inclusion bodies which are heterogeneous structures but basically consist of a system of membranous profiles and a limiting membrane of the unit type inclusion bodies appear to result from focal cytoplasmic degradation which occurs in the rapidly changing cuboidal alveolar epithelium some inclusion bodies in the developing rat lung are similar to the so called lamellar transformed mitochondria however evidence is presented suggesting that alteration of all cytoplasmic membranes may be involved in the process of inclusion body formation certain images associated with the golgi complex are interpreted as early forms of inclusion bodies there is also evidence that inclusion bodies enlarge by accretion of membranes which finally are extruded into the alveolar space inclusion bodies are formed and secreted in greater number late in fetal life and in early infancy i e at the time when the cuboidal alveolar epithelium is differentiating to the mature flattened type the latter contains no inclusion bodies on the basis of the morphologic characteristics of the inclusion bodies and the distribution of the acid phosphatase reaction it is concluded that inclusion bodies are lysosomal structures active during remodeling of the developing alveolar epithelium the possible interrelationship of inclusion bodies and pulmonary surfactant is discussed
MED	retinal detachment cataract keratoconus as ocular symptom complex in endogenous eczema with reference to personal observations the authors describe the ovular changes encountered in endogenous eczema besides the cataract which has been known to occur already for a long time retinal detachment keratoconus and keratoconjunctivitis do still belong to the symptom complex
MED	postural changes in blood distribution and its relation to the change in cardiac output 1 cardiac output and the blood content indices of the several parts of the body were measured in 18 subjects including patients with various diseases using external radioisotope counting techniques changes in these 2 parameters induced by standing were compared with each other 2 average changes in blood distribution produced by standing were as follows decrease in blood content in the lung  25 and in the heart  26 and increase in the thigh 56 were statistically significant no significant change was revealed in the head palm liver and abdomen 3 cardiac output and stroke volume decreased by standing in most of the cases recent data were added to those reported previously and were treated statistically average decrease in cardiac output was  13 in 6 control cases  35 in 16 cases with neurocirculatory asthenia and  35 in 10 cases with hyperthyroidism the difference was significant between control and neurocirculatory asthenia standing induced a substantial increase in cardiac output in a case of idiopathic nodal rhythm although there remains a doubt whether it is the ordinary response in this disease 4 significant linear correlation was revealed between per cent change of blood content in the thigh or in the lung and that of cardiac output or stroke volume induced by standing minimal blood shift was observed when the latter was extreme and vice versa this implies as follows reactivity of the heart might be influenced by posture and transmural pressure of veins and or capillaries is probably adjusted as in arterioles to compensate for changes in cardiac output
MED	comparative studies of the glycogen content of heart liver and brain before and after iodine treatment and under conditions of asphyxia blood sugar level and glycogen concentration in the heart brain and liver of rabbits after treatment with inorganic iodine depot insulin iodine and insulin combined hostacortine and hostacortine and iodine combined are being examined a control group remains untreated in a second test series the glycogen determination under asphyxia the trachea is being pinched off for three minutes is repeated contrary to the brain the glycogen content of the heart muscle is not dependent upon the blood sugar level after iodine treatment a lowering of the blood sugar becomes noticeable but also an increase in heart glycogen the liver glycogen shows greater variations the levels achieved in these test series therefore show no significant differences during asphyxia there is a significant lowering of glycogen in all three organs preliminary treatment with iodine succeeds in stopping the lowering of glycogen in the heart muscle and the brain the possible causes for this phenomenon are being discussed
MED	altered immunologic activity in sarcoidosis studies in 16 patients with sarcoidosis revealed evidence of immunologic alterations other than impaired delayed hypersensitivity transient impairment of the response of lymphocytes cultured from patients with sarcoidosis to phytohemagglutinin stimulation was found to parallel the clinical severity of the disease the hemolytic activity of serum complement was increased a disproportionate increase in serum iga was found characteristic of the hyperglobulinemia of sarcoidosis these observations indicate that an altered immune response may be important in the pathogenesis of sarcoidosis a simple hypothesis as to the specific kind of interaction of infectious agent and immunity which might result in the immunologic alterations observed is formulated and presented
MED	electron microscopy of cytoplasmic inclusions within macrophages of human tissue the fine structure of inclusions found within the cytoplasm of macrophages of human lung spleen skin lymph node and rectum has been described the inclusions appear as concentric or whorled lamellae arranged around a core each lamella is constructed of discrete parallel filaments the inclusions do not resemble currently described viruses or virus like particles nor do they resemble asbestos bodies or other known atmospheric pollutants or ingestants there is some resemblance to lipid phase systems as well as mast cell granules possibly the inclusions represent partial intracellular digestion of phagocytized tissue membranes or ingested mast cell granules respectively differences and similarities exist between the inclusion bodies of macrophages and the granules of mast cells such variations could be due to alterations in mast cell granule morphology before or after macrophage ingestion cytologic distinctions between macrophages laden with mast cell granules and mast cells proper remains obscure and requires additional experimental evidence for clear electron microscopic differentiation of these two cell types the exact nature of these highly structured bodies remains speculative
MED	histological research on the lens in condition of hypoxia changes in the mitotic activity of the epithelium the effect of hypoxia on the mitotic activity of the cells of the lens epithelium was studied in 24 rats of the same strain and weight the hypoxia was obtained in the decompression chamber the results show that the mitotic activity of the lens epithelium is depressed at any of the examined altitudes 6 500 8 000 9 500 m in particular a marked reduction in the number of the prophases and an accumulation in metaphase was observed the results were examined from the statistical standpoint and discussed
MED	rate of change of carbon dioxide tension in arterial blood jugular venous blood and cisternal cerebrospinal fluid on carbon dioxide administration 1 the rate of change of p in arterial blood and cisternal c s f was measured following 5 percent co administration in eight anaesthetized patients undergoing routine air encephalography ventilation was maintained constant throughout the procedure by a respirator in three of the experiments the rate of change of p in the jugular venous blood was also measured 2 the rise in p varied between 25 7 and 14 8 mm hg the final samples of blood and c s f were taken 20 25 min after the start of co administration in five experiments at this time the mean rise in p was 65 9 maximum range 68 1 61 6 percent of the rise in p in the remaining three experiments the final samples were taken at 15 min when the rises in p were 53 2 39 4 and 38 1 percent of the arterial change 3 the increases in p were 57 5 76 2 and 76 1 percent of those in the arterial blood the changes in p in the c s f were smaller than in the jugular venous blood in all three experiments in two of the experiments the final samples were taken 15 min after the start of co administration when the increases of p in the c s f were 68 5 percent and 50 percent of those in jugular venous blood in one experiment where the final samples were taken at 20 min the increase in p was 89 percent of the rise in p 4 there was a delay following the start of co administration in the rise of p in jugular venous blood and in the c s f this delay was about 1 min in the jugular venous blood but in the c s f it varied from 1 6 to 4 2 min mean 2 3 5 the rise of p in blood and c s f was exponential the rise in p in all experiments consisted of a fast component with time constants which varied between 0 2 and 0 9 min mean 0 5 and a slow component with time constants varying between 6 7 and 14 7 mean 11 6 the rise in p and p consisted of only one component the time constants for the changes in jugular venous blood were 2 1 3 8 and 4 3 min whilst in the c s f they varied between 6 7 and 14 7 mean 11 6 6 it is probable that about 40 percent of the increase in ventilation following co administration is due to stimulation of an area in the antero lateral surface of the medulla sensitive to changes in ph or p mitchell et al 1963 this area is superficial and ventilation is affected by changes in the p of the overlying c s f it can be predicted from our experiments that the rise in p on co administration will take some 30 min to be complete this may explain the slow rise in ventilation on co breathing when compared with the rate of rise of arterial and jugular venous p
MED	studies on the compound lipids from x ray irradiated animal ii biological and biochemical properties of the compound lipids in the x ray irradiated rabbit organs for the purpose to clarify the causes of x ray disturbances a series of experiments have been conducted on biological and biochemical properties of compound lipids extracted from normal and x ray irradiated rabbit organs with a special reference to the p  labeled compound lipids uptake inhibitory action to l cell proliferation and uncoupling of oxidative phosphorylation and the following results have been obtained the compound lipids lysophosphatide rich fraction isolated from the x ray irradiated rabbit organ have been found to possess a strong hemolytic action and also an action to inhibit the cell proliferation as well as to accelerate the respiration of the mitochondria in the rabbit liver and spleen it has also been proven that they act as to induce a marked swelling of mitochondria to impede the formation of high energy phosphate as well as to act as an uncoupler of oxidative phosphorylation in vivo in the test to see the uptake of p  labeled compound lipids by various organs a marked uptake has been observed in spleen bone marrow and liver of both irradiated and non irradiated groups further the uptake of p  labeled compound lipids in the rabbits given intravenous injections of compound lipid fraction for 30 consecutive days previously has been found to be greatest in pancreas followed by bone marrow spleen liver in the order mentioned in male group whereas it is greatest in spleen followed by liver and bone marrow in the female group with these results the discussion was conducted concerning the relation between the lipid metabolism and x ray disturbances
MED	cesium 131 uptake and distribution in the human heart an analysis of cardiac scans in 104 patients when properly used cesium 131 is a satisfactory agent for the study of cardiac morphology by photoscanning which we believe is a useful adjunctive diagnostic procedure in patients for whom the results of other methods of evaluation are at variance with the clinical symptoms of cardiac disease the studies reported here suggest that perhaps infarction of a subclinical type size or location may occur earlier than has been previously thought and that the damage it leaves may not be detectable by any means other than autopsy or a technique such as scanning we have not yet been able to measure the actual concentration of cesium 131 in the heart at autopsy so that the cold and cool areas could be examined by histologic sections
MED	oxygen consumption of paralysed men exposed to cold 1 oxygen consumption and carbon dioxide output were measured when human subjects were cooled for 80 210 min two subjects were normal one had been almost completely paralysed below the neck by poliomyelitis and two were unconscious as a result of intracranial damage and were observed with and without paralysing doses of muscle relaxants d tubocurarine and gallamine 2 when normal subjects and unconscious subjects receiving no drugs were cooled oxygen consumption and carbon dioxide output rose 3 when subjects paralysed by disease or drugs were cooled oxygen consumption and carbon dioxide output were not increased 4 these observations are consistent with the view that in man the increase in metabolism on cooling for periods up to 31 2 hr occurs solely in skeletal muscle
MED	heparin levels during and after hypothermic perfusion 1 perfusion temperature influences the rate of heparin loss during extracorporeal circulation and therefore the requirement of re heparinization 2 heparin half lives of approximately 13 4 hours and 21 2 hours were calculated during perfusions conducted at average temperatures of 31 5 and 22 6 c respectively 3 the rate of heparin loss during extracorporeal circulation is inconstant in an individual and variable between individuals so that exact neutralization requires an accurate estimation of the heparin concentration present at the end of perfusion 4 the protamine titration test provides a crude but simple and satisfactory means of monitoring free heparin levels 5 complete neutralization of heparin is an important factor in minimizing postoperative blood losses 6 protamine is a less efficient neutralizing agent than polybrene at the same dosage level it may be most effective in divided dosage 7 rebound was detected in 5 of 45 cases studied although in only one instance was it of a degree likely to be significant 8 significant prolongation of the clotting time resulting from excess neutralizing agent was not evident in this study
MED	platelet sequestration in man i methods current methods of labeling platelets with chromium using ethylenediamine tetraacetate edta as an anticoagulant were found to cause rapid hepatic sequestration of nearly all the transfused platelets about 50 returned to the circulation but then were partially destroyed in the spleen less than one third survived evidence is presented which indicates that edta is injurious to platelets when an acid citrate medium that buffered plasma at ph 6 5 was used as an anticoagulant 36 to 85 of the labeled platelets survived average 62 and marked temporary sequestration did not occur studies in thrombocytopenic persons showed that circulating platelet cr activity measures the true survival of such transfused platelets the survival and sequestration of platelets were studied in normal subjects the survival data support the concept that platelets die chiefly by a process of senescence external scintillation scanning of the various organs suggests that normally the majority of platelets is destroyed in the liver
MED	acute leukemia associated with phenylbutazone treatment a review of the literature and report of a further case the possible toxic reactions to phenylbutazone have been listed and a review of the literature of haematological complications has shown that 16 deaths attributable to agranulocytosis aplastic anaemia and thrombocytopenia have been recorded the association between leukaemia and phenylbutazone first suggested by bean 1960 has been amplified by further reports which have been reviewed a further case history has been presented of the 15 patients with acute leukaemia in which the association has been recorded there were other possible leukaemogenic factors in three and in a further three the drug had been given for only a short time before the leukaemia was diagnosed however in the remaining nine the histories are such that the phenylbutazone ingestion may have been associated with the development of the leukaemia further studies which should include matched controls are indicated and will be required before a definite opinion can be given as to any causal relationship between the drug and the disease
MED	absorbed radiation dose and excretion of cesium 131 in humans data relating to the effective half life absorbed dose of radiation and excretion rates of cesium 131 have been presented cesium 131 is an excellent material for cardiac scanning since a very low amount of radiation is absorbed  dash a dose of the order of one twentieth that received in diagnostic x ray studies of the gastrointestinal tract absorption of radiation can be reduced further by the administration of a thiazide type of diuretic and probably by catharsis after the scan
MED	radiocardiography principles and methods the aa show the importance of radiocardiography as a method to evaluate the cardiac output the ventricular volumes and the pulmonary blood volume in this first paper they are particulary concerned with some technical aspects which are very important to collect data the position of the collimator on the precordium the injection of isotopes through a catheter just behind the ventricle near the tricuspid valve the selection of ratemeter constants the velocity of paper on the recorder and the way to read the area of the curve were specially discussed finally they present the formula used to calculate cardiac output ventricular volumes and pulmonary blood volumes
MED	reaction of the adrenal cortex during controlled experimental hypothermia the stress reaction caused by hypothermia was studied in rabbits subjected to controlled hypothermia by immersion in an icebath some of the animals were re warmed to anesthetize the animals pentobarbitone sodium nembutal was given intraperitoneally and in some cases followed by ether anesthesia further the stress reaction produced by pentobarbitone alone was studied in five animals and that of ether anesthesia alone in three no anesthesia was given to the three rabbits placed in the refrigerator the variation in distribution and amount of adrenocortical lipids served as an indicator for evaluation of the stress reaction in all the hypothermia tests there occurred changes in the distribution and amount of cortical lipids denoting a stress reaction brought about by hypothermia in rabbits the barbiturate did not seem to inhibit the stress reaction this may be attributed partly to the test animal as such and partly to the fact that shivering of some extent always occurred during the hypothermia experiments
MED	use of a cross circulation technique in studying respiratory responses to co the effect of hypercapnia and hypocapnia on ventilation was investigated in cross circulated dogs in which the recipient dogs head and neck regions were perfused by blood from a donor dog hypercapnia of the donor dog was produced by administering co  o  n gas mixtures in the inspired air hypocapnia was produced by hyperventilating the donor dog with the aid of a respiratory pump when the donor dog was hyperventilated the ventilation of the recipient was maintained at or just below its resting level and it was independent of the arterial pco of the donor the donor dog was apneic when the artificial hyperventilation was suspended and this response was not abolished by vagotomy bilateral vagotomy caused an increase in ventilation in the recipient when its head was perfused by hypocapnic blood bilateral removal of the carotid receptors did not influence the response to co qualitatively although there was some reduction in the ventilation of the recipient to cephalic hypercapnia the ventilation of the recipient dog was best correlated to the ph and pco of its cerebrospinal fluid in both hypercapnic and hypocapnic states
MED	action of phytohaemagglutinin in vitro on the lymphocytes of chronic lymphoid leukaemia the in vitro action of phytohaemagglutinin has been the subjects of a comparative investigation of the lymphocytes of 13 normal subjects and of 15 cases of chronic lymphatic leukaemia in both groups there is cellular change shown by the appearance of large basophil nucleolated cells showing mitotic activity in all the cases of lymphatic leukaemia the percentage of cells undergoing such change is lower than in normal subjects and the transformation occurs more slowly the two phenomena are more striking the higher the initial leucocytosis these results suggest in chronic lymphatic leukaemia the cells affected by the transformation are residual normal lymphoid elements leukaemic lymphoid cells appear to be incapable of this transformation
MED	demonstration of ventricular aneurysms by radioisotope scanning radioisotope scanning of the cardiac blood pool after the intravenous injection of i  labeled iodipamide was carried out in 14 patients with ventricular aneurysm in 4 the aneurysm could be demonstrated on neither the anteroposterior chest roentgenogram nor the scan in 5 the aneurysm was apparent on the radiograph but the blood pool did not enter the area suggesting a thrombus within the aneurysm in 5 the aneurysm was detectable on the film and was also seen to be filled with radioactivity on the scan presumably these findings showed that a thrombus had not yet formed blood pool radioisotope scanning appears to be another tool in the diagnosis of ventricular aneurysm useful also in demonstrating in some patients the presence or absence of an intraluminal clot within the aneurysm
MED	propagation of lactic dehydrogenase elevating virus in cell culture primary cultures of adult mouse lung spleen and liver and of mouse embryo support the multiplication of the lactic dehydrogenase elevating virus such cultures produced virus continuously until they had been subcultured 2 3 times this corresponded to 20 weeks in the case of lung and spleen and to 2 3 weeks with cultures of embryo viral multiplication was not accompanied by cytologic alterations in the cells or by changes in their rate of synthesis of nucleic acids or protein infection did not cause detectable changes in either the production of ldh or in its release from cells
MED	transformation of bovine cells in vitro after inoculation of simian virus 40 or its nucleic acid cells of bovine embryonic lung tissue in culture were inoculated with simian virus 40 sv 40 or a phenol extract of a high titer suspension of sv 40 both the virus and the nucleic acid preparation induced proliferative morphological changes characteristic for sv 40 transformation non infected control cultures and cultures which were inoculated with a preparation of nucleic acid exposed to dnase and maintained under the same conditions as infected cultures showed a regular fibroblastic growth cell lines of rapidly growing transformed cells have been obtained most attempts to isolate virus from the transformed cells were negative but minute amounts of virus were recovered from occasional passages
MED	rapid transformation of human fibroblast cultures by simian virus 40 the risk of systemic embolism is assessed in a group of 754 patients with chronic rheumatic heart disease followed over a period of 5 833 patient years the incidence of embolism was 1 5 per patient year for the whole group it was seven times higher in atrial fibrillation than in sinus rhythm when the duration of atrial fibrillation was known it was found that one third of the emboli occurred within one month and two thirds within 12 months after the onset of atrial fibrillation the incidence of embolic recurrences was 8 per patient year irrespective of the nature of the cardiac rhythm but 66 of the recurrences took place within 12 months of the initial embolic episode mitral valvotomy did not eliminate the danger of embolism it is questionable whether it reduced its incidence anticoagulant treatment reduced the incidence of embolic recurrences
MED	the tissue reaction to hyperbaric oxygen hyperbaric oxygen damages tissues exposed in vitro but their sensitivity varies if exposure is limited some tissues may recover the effect appears to depend on oxygen tension rather than raised pressure per se the tissue reaction may be involved in the clinical application of hyperbaric oxygen
MED	attitudinal factors in congenital heart disease this study considers the behavioral implications of congenital heart disease for the pediatric patient his siblings and his parents the effects of a disease on the child on his siblings and on his parents and the interplay among these individuals are explored the impact of the physicians diagnosis is illustrated by the induced significant changes in family attitudes which are not necessarily related to disease severity or child incapacity poorer adjustment and anxiety in the cardiac child related more highly to maternal anxiety and pampering than to his degree of incapacity maternal protectiveness and pampering were significantly greater in the cardiac than in the normal group and were highest in the cyanotic group the best predictor of maternal protectiveness was maternal anxiety and it was found that the addition of other variables such as incapacity and child dependence failed to improve prediction substantially maternal anxiety seemed related to the presence rather than to the severity of the heart condition
MED	maternal anxiety during pregnancy and adequacy of mother and child adjustment eight months following childbirth fifty pregnant women were administered a battery of psychological tests on the basis of scores obtained from the manifest anxiety scale these pregnant women were dichotomized into a high anxiety group and a low anxiety group eight months following childbirth the mothers and children were seen for a psychological assessment it was found that the women in the high anxious group evidenced significantly more negative childrearing attitudes that is the high anxious mothers obtained significantly higher scores on the hostility and control factors measured by the pari on the basis of the examiners ratings of the mothers personality traits it was found that the women who were highly anxious during pregnancy received much less favorable personality ratings at the time of the 8 month assessment moreover there was a significant difference in the proportions of mothers in the two groups who received a favorable rating from the examiner on the basis of his observation of the mother child interaction during the session in studying the children of these mothers it was found that the children of the low anxious mothers received a significantly higher developmental quotient on the infant mental scale in keeping with this finding they also obtained a higher developmental quotient on the motor scale although on this aspect of the intellectual assessment the difference was not statistically significant also the children from the low anxious mothers tended to receive a score indicative of a more favorable general emotional tone than did the offspring of the high anxious mothers this difference between the two groups of children was not statistically significant in general the findings were consistent with the predictions that the children who were being reared by women who had been highly anxious during pregnancy would fare less well on tests of intellectual development and indices of emotional adjustment the findings also were in keeping with the prediction that the highly anxious women during pregnancy would evidence less desirable parental attitudes during their childs early development and that they would present a less favorable personality picture at a time approximately 8 months following pregnancy
MED	maternal separation in the rhesus monkey the present study involved separation of eight monkey mother infant pairs for a period of two weeks and measurement of the behavior of the infants before during and after reunion with their mothers and of the mothers before and after reunion all infants showed emotional disturbance in response to separation and drastic decreases in play and other complex social behaviors while separated it is clear that infant mother separation produces emotional disturbance in both human and macaque infants and that the patterns of responses following separation are similar in both species the results obtained in studies of monkey infant mother separation indicate that sheer physical separation is the crucial aspect of maternal separation for monkeys undoubtedly other factors associated with separation from the mother are vitally important for human children and may account in part for the absence or rarity of the detachment stage as seen in human response pattern in separated monkey infants the overall results show considerable similarity in the responses of human children and infant monkeys to separation from the mother
MED	the ophthalmologists role in the management of dyslexia dyslexia is a clinical entity characterized by subnormal reading ability in a person of average or above average intelligence it is a disease which has different causes in different children the causes include brain damage in the language area hereditary predisposition and such ophthalmic factors as hyperopia muscle imbalance aniseikonia or visual immaturity emotional disturbances educational immaturity and cerebral dominance may also play some role in the etiology of this condition the universal symptom is poor reading ability however these cases frequently have other associated symptoms such as poor writing difficulty in reading and writing numbers inability to read or write musical notes and disorientation for left and right many of these patients develop personality maladjustments visual fields often reveal a hemianopia in any group of poor readers a large percentage will have ocular neurologic psychiatric or psychologic abnormalities and or a strong hereditary tendency the degree to which reading can be learned depends upon the ability of the individual to adjust to the psycho physiologic needs that are present at the time he reaches reading age in school if compensating abilities are present and if the childs reaction is a favorable one he may read well in spite of unfavorable factors if not he may become a poor reader these children should be recognized in their first year of school a complete medical work up should be managed by an ophthalmologist a complete ophthalmic examination should first be performed and all possible visual anomalies should be corrected the ophthalmologist may want a psychometric evaluation a neurologic opinion to determine the role of organic brain damage psychiatric consultation for evaluation of emotional disturbances pediatric consultation for evaluation of the status of the general health and or consultation by an otolaryngologist to determine the patients hearing ability with all the necessary information at hand the ophthalmologist will be able to recommend corrective medical therapy and to advise the parents and teachers about available remedial reading aids the prognosis is good for most patients since they are of average or above average intelligence nearly all cases can be helped
MED	unusual course of internal carotid artery accompanied by bitemporal hemianopia a case is reported with bitemporal relative hemianopia craniotomy showing internal carotid arteries to have an unusual course corresponding to the carotid siphon with resultant change in shape of the optic nerves abnormalities of the carotid siphons could not be detected on reviewing the carotid angiograms evaluation of the optic nerves relationship as can be measured on the pneumograms indicated that the optic nerves in this case were exposed to compression from the abnormal arteries
MED	frontal lobes and vision the influence of the frontal lobe on vision is discussed based on the presentation of a rather unusual case after the operation of a right frontal brain abscess which never had led to papilledema there was a pronounced diminution of the visual capacities of the patient gradually these disturbances regressed to the point of return of full visual acuity but there remained a hemianopic field defect this and psychological defects in the sense of a partial visual agnosia which latter are also regressing very well prompted a discussion of those neuroanatomical and neurophysiological observations pertinent to the findings in this patient the many data on the fronto occipital connections in subhuman primates point to the role of the frontal lobe area 8 in the development of visual disturbances in the sense of a temporary hemianopia with partial visual agnosia and some intellectual deficits contrary to a single observation in an anthropoid ape our case would seem to indicate that the aforementioned combination of symptoms may originate in the frontal lobe and we hope it will prompt other long term follow up studies of similar patients the continued observation of this patient and perhaps of others will give a possibility to gain insight into the role of the frontal lobe in vision as has been assumed for animals
MED	physiologic bitemporal hemianopsia in pregnancy a severe case of bitemporal hemianopsia occurring late in pregnancy is presented the patient illustrated a typical rapidly progressive course and rapid recovery with complete return of visual fields and visual acuity after delivery was accomplished the presumed pathologic physiology of this entity is briefly reviewed
MED	evoked response in visual disorders 1 erg and ver have been recorded from eyelid and lateral occipital electrodes in response to diffuse stroboscopic stimulation in 45 normal subjects ver was found to be composed of an early triphasic potential arising from the occipital region wave i was present in 67 percent of subjects wave ii in 97 percent and wave iii in 100 percent later waves were inconstant and contained components from the vertex reference no overall asymmetry in ver from right to left was found in normal subjects although average asymmetry with smaller side compared to larger was 19 percent 12 5 on monocular stimulation the contralateral ver was regularly larger than the ipsilateral reflecting predominant retinal representation of the temporal field 2 a statistically determined criterion of 50 percent depression in wave ii successfully identifies most patients with hemianopic defects involving the central 10 percent of visual field on tangent screen campimetry latency asymmetry of six msec or more and grossly asymmetrical aberrant wave forms are seen in some patients with diffuse cerebral disease and hemianopic defects 3 severe or diffuse retinal disease is associated with alteration or loss of erg and ver on stimulation of the involved eye 4 optic nerve disease is indicated by bilateral loss or suppression of ver on stimulation of the involved eye erg is normal 5 bilateral prechiasmal involvement is associated with complete suppression of ver if only waves i and ii are lost disease is probably but not conclusively demonstrated 6 involvement of nasal retinal fibres is indicated by reversal of the normal contralateral preponderance of ver on monocular stimulation these changes are observed in chiasmal disease 7 retrogeniculate blindness is associated with loss of early ver and preservation of late response nonspecific projections are felt to contribute to the late cortical response to photic stimulation
MED	optokinetic nystagmus and occipital lesions six cases are presented to invalidate the rule that horizontally symmetric optokinetic responses indicate a vascular etiology in patients with occipital lobe type hemianopias the converse of this rule is in our experience still a valuable observation that is asymmetry of horizontal optokinetic responses accompanying an occipital type field defect is a strong indication of a mass lesion optokinetic nystagmus may be helpful therefore as corroborative evidence in diagnosing occipital lobe tumor but not in ruling it out
MED	anaphylactoid shock induced by oral penicillin and resulting in gerstmanns syndrome an anaphylactoid reaction to oral penicillin in a 46 year old woman is described after hours of unconsciousness and weeks of confusion she was left with a residual gerstmanns syndrome these reactions are less rare than is generally supposed symptomatology treatment diagnosis and mechanism are discussed and some of the relevant literature is briefly reviewed
MED	disturbances of the verbal body image a particular syndrome of sensory aphasia 1 the pto syndrome of the dominant hemisphere varies according to the extent and depth of the lesion in the angular and supramarginal areas the mildest clinical syndrome consists of a vague contralateral sensory impairment associated with dyscalculia dysgraphia dyslexia and difficulty in naming a more extensive lesion is needed to cause the wide variety of classical signs described in parietal lobe disease among them being gerstmanns syndrome which is usually found in association with other manifestations of parietal loss case 1 an even more extensive corticosubcortical lesion in the area leads to complete disintegration of naming and understanding of speech cases 3 4 and 5 2 attention is drawn to the difficulties arising from lack of differentiation between the concrete gnostic body image and the abstract verbal body image in investigation of these patients the aphasic syndrome should be differentiated from disturbances of gnosis by application of separate non verbal methods of testing to elicit the impairment of the gnostic body image the latter may be well compensated for and it is apparently unimpaired in the presence of an aphasic syndrome limited to the verbal body image 3 disturbances of speech in pto lesions if investigated along quantitative scales of impairment of repetition understanding and naming show a regular interrelation nomination is the most affected understanding is less affected repetition is the best preserved function cases 1 4 the same interrelation of these functions is found with regard to the verbal body image however understanding and naming of parts of the body show far greater disintegration than understanding and naming of any other categories of words all cases presented here if the aphasic syndrome is subsiding finger aphasia with some other minor disturbances of verbal body image associated with acalculia may persist case 1 thus gerstmanns finger agnosia may represent a partial impairment of the verbal body image and be limited to finger aphasia 4 it is assumed that the verbal body image differs from other categories of verbal symbols owing to the mainly proprioceptive vestibular and tactile experience forming its specific physiologic background telereceptive experience is of minor importance in the initial development of the understanding of words defining the body image in the patients described here the selectively worse aphasic impairment of the verbal body image as compared with other categories of words seem to confirm this assumption
MED	chromosomal patterns in cancer patients during treatment radiation damages the chromosomes of human cells and through short term cultures of white blood cells some of this damage can be assessed patients with cancer were selected for this study because of the large portions of the blood forming tissues irradiated in the course of treatment chromosomal damage may be quantitative with variations from the normal number of 46 or qualitative thereby showing structural aberrations counting the chromosomes in cells from cultures grown prior to therapy and at intervals during treatment enables us to determine the variation stained preparations examined microscopically allow us to recognize these abnormalities which are apparent before during and after radiotherapy the damage appears to be largely random in the chromosomes affected in the different cancers and the specific aberrations differ from cell to cell however there does seem to be some correlation between the appearance of persistent aberrant chromosomes and their frequency while the peak incidence or plateau may remain unchanged the frequency may change
MED	a few interesting neurologic manifestations of migraine migraine is a complex vascular phenomenon presumably of genetic origin which through changes induced by either vasoconstriction or vasodilitation can produce interference with the neurologic system and result in many bizarre and alarming clinical pictures a few examples of the more interesting neurologic manifestations have been shown
MED	visual neglect clinical trainees in nursing and in psychology from boston college and simmons college boston mass collected data and observed patients under the direction of the authors in a pilot program designed to measure visual spatial neglect and to develop rehabilitative material these measurements and exercises might also be used by nurses in their care of those patients who have had cerebral vascular accidents the diversity of daily activities in which the patient becomes involved during his hospitalization should provide some indication of the extent to which the compensatory visual neglect therapeutics have been effective more formal estimates can be obtained by re administering the battery of visual neglect tests at periodic intervals nursing personnel adopting a program of therapeutics such as this must bear in mind that patients suffering cerebral insult are usually less adaptive than their nonbrain injured peers they develop new habit patterns slowly and regression often will follow apparent fixation at a more adaptive level of response habituation 11 however experimental inquiry has shown that the dimension of behavioral difference between the brain injured adults and normal adults is one of degree rather than kind  dash a difference that skilled nursing can often reduce 12
MED	respiratory changes after open heart surgery patients who undergo cardiac surgery with extracorporeal circulation develop significant alveolar arterial oxygen tension differences and venous admixture in the early post operative period up to 50 of this abnormality is due to anatomical right to left shunting through the lungs the remainder is most likely to be due to ventilation perfusion inequality the changes appear to be completely reversible the cardiopulmonary bypass procedure may be responsible for initiating the underlying pathology since changes of this magnitude were not found in cardiothoracic surgery patients in whom this technique was not required
MED	cardiac malformations associated with ventricular septal defect in this study 46 necropsy proved cases of ventricular septal defect associated with another anomaly but not part of a recognized complex were selected the associated anomalies were classified as 1 obstructive or positional anomalies of the great vessels 2 anomalies responsible for additional shunts 3 anomalies causing intraventricular obstruction and 4 aortic valvular insufficiency clinical findings were often those of the ventricular septal defect and the findings related to the associated lesion were frequently obscure even with special studies including cardiac catheterization and angiocardiography there was often failure to arrive at a complete diagnosis the findings which led to an erroneous or incomplete diagnosis have been presented when a complete diagnosis was made preoperatively the procedures leading to it have been outlined while the diagnostic approach varies with the malformations which may coexist with ventricular septal defect it was observed that aortography and selective left ventricular angiocardiography were most commonly helpful in identifying occult malformations associated with ventricular septal defect it is therefore recommended that complete studies including left sided cardiac catheterization with left ventricular angiocardiography and aortography should be considered in all cases in which the clinical electrocardiographic and right sided cardiac catheterization studies are not entirely typical for isolated ventricular septal defect
MED	anatomic types of single or common ventricle in man morphologic and geometric aspects of 60 necropsied cases in 60 necropsied cases of single or common ventricle in man four major unrelated ventricular malformations were found 1 absence of the right ventricular sinus in 47 cases 78 percent designated type a 2 absence of the left ventricular sinus in 3 cases 5 percent type b 3 absence or rudimentary development of the ventricular septum in 4 cases 7 percent type c and 4 absence of both ventricular sinuses and of the ventricular septum in 6 cases 10 percent type d three types of relationship between the great arteries were present a normal solitus interrelationship in 9 cases 15 percent designated type 1 d transposition the transposed aortic valve lying to the right dextro or d relative to the transposed pulmonary valve in 25 cases 42 percent type ii and l transposition the transposed aortic valve lying to the left levo or l relative to the transposed pulmonary valve in 26 cases 43 percent type iii in none was the inversus interrelationship type iv displayed three types of visceral and atrial situs were found solitus or normal in 50 cases 83 percent inversus an exact apparent mirror image of normal in 2 cases 3 percent and heterotaxy the uncertain visceral and atrial situs associated with asplenia in 8 cases 13 percent the 60 cases were classified segmentally according to the anatomy of the three cardiac segments the great arteries the ventricular sinuses and the atria the classic single ventricle with a rudimentary outlet chamber was found morphologically to be a large left ventricle with a right ventricular infundibulum the sinus of the right ventricle being absent type a the myocardium of the right ventricular infundibulum of the right ventricular sinus and of the left ventricular sinus was identified by the distinctive gross morphologic characteristics of each the planes of the atrial and ventricular septa and the relationships between the great arteries at the semilunar valves were measured as projections upon the horizontal plane relative to the anteroposterior line an approach to cardiac anatomy is presented which is segmental morphologic and geometric this approach has angiocardiographic electrocardiographic and embryologic applications
MED	congenital heart disease in the adult events in the natural course of 310 adult patients with proved significant congenital cardiac anomalies have been reviewed to determine incidence longevity complications and cause of death atrial septal defect and patent ductus arteriosus were the most frequently encountered lesions and comprised over one third of the entire series ventricular septal defect and pulmonic stenosis made up almost a quarter of the group twenty two instances of the eisenmenger syndrome secondary to a variety of shunting lesions are included bacterial endocarditis sudden death and cardiac decompensation were the greatest threats to these patients symptoms were minimal until the appearance of heart failure which was the most common cause of death especially with older patients sudden death occurred most often in patients with ventricular septal defect although the clinical features are usually characteristic of a congenital malformation young adults with acyanotic congenital heart disease are often misdiagnosed as rheumatic and in older patients presenting manifestations are frequently attributed to arteriosclerotic heart disease at times an associated acquired cardiovascular disorder may alter the basic syndrome three quarters of the patients survive and continue under observation the ability of many to live active productive lives and to withstand stress surgery both cardiac and non cardiac and pregnancy was impressive further observation of the patient with congenital heart disease but without surgical intervention is essential for accurate evaluation of the long term efficacy of cardiac surgery
MED	a study of ventricular septal defect associated with aortic insufficiency clinical electrocardiographic radiographic and hemodynamic findings in 12 children with the combination of a ventricular septal defect and aortic insufficiency are presented the left to right shunt was determined to be small or moderate in all and significant aortic insufficiency was documented by aortography in 11 patients clinical indication of aortic insufficiency as manifested by an aortic diastolic murmur first appeared at an average age of 6 years in 7 patients with concomitant widening of the pulse pressure in 4 progressive left ventricular hypertrophy was noted electrocardiographically with progressive cardiac hypertrophy and aortic dilatation on x ray examination in 2 patients progression of the hemodynamic disability does not appear to be common in childhood however
MED	ventricular septal defect and aortic regurgitation clinical hemodynamic and surgical considerations the clinical hemodynamic angiographic and anatomic findings in fifteen patients with ventricular septal defect complicated by aortic regurgitation are presented in this combination of malformations the aortic regurgitation is acquired and results from prolapse of an aortic valve leaflet into the septal defect the strategic location of the septal defect in relation to the aortic leaflets appears to be more important to the development of this complication than the size of the defect or the magnitude of the shunt through it the onset of aortic regurgitation occurs during early childhood and once present tends to become more severe careful observation of patients with these defects is indicated following the appearance of aortic regurgitation since rapid progression to severe left ventricular failure is not uncommon ventricular septal defect and aortic regurgitation must be distinguished from other cardiovascular abnormalities producing a wide pulse pressure with a continuous or to and fro murmur cardiac catheterization and thoracic aortography are the diagnostic procedures most helpful in this differentiation the operative treatment of ventricular septal defect and aortic regurgitation is reviewed and on the basis of the present and previously reported results suggested plans for surgical management are presented
MED	current techniques in the surgical approach to aortic and mitral valvular disease 1 the aortic and mitral valves can be operated upon successfully and totally replaced with a prosthetic device of the ball valve type with good long term results seventy four cases are reported 2 in aortic valvular disease the outcome in the immediate postoperative period is influenced primarily by the presence of calcific aortic stenosis as well as the presence or absence of disease in the coronary arteries 3 we have significantly decreased the appearance of a low output syndrome postoperatively in patients who are suffering from severe mitral disease by leaving the papillary muscle chordae tendineae mural leaflet relationship intact we feel this adds strength to each contraction 4 there have been no late deaths in the follow up period to date thirty months in any patient with replacement of aortic or mitral valves with the ball valve prosthesis
MED	effects of aortic regurgitation on left ventricular performance direct determinations of aortic blood flow before and after valve replacement the volume of regurgitant blood flow and its effects on the performance of the left ventricle were assessed at operation in 14 patients with varying degrees of aortic regurgitation instantaneous forward and regurgitant flows in the ascending aorta were measured with a sine wave electromagnetic flowmeter simultaneously with left ventricular and aortic pressures in eight patients who had aortic regurgitation without associated stenosis 63 to 75 percent of the total forward stroke volume regurgitated during the succeeding diastole the calculated regurgitant orifice areas ranged from 0 13 to 0 44 cm m after replacement of the aortic valve with a starr edwards prosthesis the absence of regurgitant flow was proved in every patient and the records of aortic blood flow closely resembled those seen in patients with normal aortic valves net forward blood flow increased by an average of 60 percent total left ventricular stroke volume fell 42 percent and the mean aortic pressure rose 29 percent the pressure work of the left ventricle was elevated preoperatively in five of the eight patients average 89 g m stroke m and fell significantly to an average of 34 g m stroke m after valve replacement kinetic ventricular work was high in seven of the eight patients and comprised 10 percent of total work before replacement but only 4 8 percent afterward similar observations were made in five patients with aortic stenosis and associated aortic regurgitation ranging in severity from 24 to 72 percent of total forward stroke volume in four patients in whom the valve was replaced no residual regurgitation was present afterward and net forward flow rose an average of 49 percent kinetic left ventricular work was extremely high in every patient and averaged 26 percent of total work preoperatively and 13 percent after valve replacement in this group pressure work was variable both before and after operation the studies described provide definitive information concerning the effects of aortic valve disease on left ventricular performance in man and document the favorable changes in flow pressure and left ventricular work which immediately follow aortic valve replacement
MED	the absorption and hepatic uptake of orally ingested radioactive vitamin b in hepato splenic bilharziasis the absorbed plasma radioactivity and hepatic uptake of orally ingested vitamin b tagged with co were measured in 52 subjects 26 normals and 26 suffering from bilharziasis the results of the present work indicate that the absorption and hepatic uptake of this vitamin are within normal limits in hepatosplenic bilharziasis irrespective of the stage of the disease the size of the organs affected and the presence or absence of associated peripheral neuritis
MED	early effects of digitalis on central hemodynamics in normal subjects the intravenous administration of lanatoside c in 7 normal subjects had the following effects 1 an early significant reduction of heart rate 2 a significant transient reduction of cardiac output 3 a significant increase of the stroke volume initially accompanied by a significant rise of the end diastolic volume with unchanged systolic rate of emptying the increase of end diastolic volume seems to be related to the lengthening of the diastolic filling period later on the systolic emptying rate increases and the ventricular volumes decrease suggesting an inotropic effect of the drug 4 a significant increase of pulmonary blood volume parallel to the increase of the stroke volume suggestive of a passive relation between the two variables
MED	measurement of pericardial fluid correlated with the i  cholografin and ihsa heart scan in 23 patients undergoing open heart surgery in whom the pericardial contents were accurately measured and in 11 additional patients examined at autopsy or by pericardiocentesis isotopic photoscans of the heart were made and the results were correlated the most accurate means of diagnosis of pericardial effusion was found to be the ratio of the maximum transverse cardiac diameters on scan and roentgenogram in patients with less than 100 cc of pericardial fluid this ratio was greater than 0 80 and it was less than this in cases of effusion of 200 cc or more measurement of the difference of these diameters and visible separation of the cardiac blood pool from the pulmonary vasculature and liver aided in the diagnosis pericardial effusions of 200 300 cc or greater can be detected by isotopic photoscanning although cardiac dilatation and or hypertrophy decrease the sensitivity of the technique somewhat a definite diagnosis of pericardial effusion can be made even when cardiomegaly exists
MED	aneurysm of the membranous septum 1 aneurysms of the membranous septum are relatively rare lesions presumably developing on a congenital basis these aneurysms originate in the left ventricle immediately beneath the aortic valve and bulge into the right ventricle the septal leaflet of the tricuspid valve or into the right atrium 2 many of these aneurysms do not produce symptoms others may cause right ventricular outflow tract obstruction or may rupture and result in a septal defect the resulting shunt will be from the left ventricle into the right atrium or ventricle 3 an aneurysm of the membranous septum may be an isolated abnormality or be associated with other congenital cardiac defects particularly aortic valvular insufficiency membranous septal aneurysms may be the site of bacterial endocarditis or thrombus formation 4 aneurysms resembling those arising from the membranous septum may occur as part of the complex of deformities produced by an endocardial cushion defect however the angiographic features diagnostic of a cushion defect can still be recognized 5 the presence of a septal aneurysm can be established only by angiocardiography the diagnostic features as seen on the left ventricular angiocardiogram are presented
MED	distribution of transfused tritiated cytidine labeled leukocytes and red cells in the bone marrow of normal and irradiated rat in normal rats and after total body irradiation with 550 r of x rays the fate in the bone marrow of labeled nucleated and red cells of transfused peripheral blood was observed autoradiographically labeled nucleated cells most of which were lymphocyte like cells readily migrated into the marrow parenchyma in normal animals 2 cells 1 000 parenchymal cells hr following irradiation to at least 27 51 hr this migration appeared to be relatively increased beyond this time parenchymal areas were more difficult to be defined as such labeled red cells were rarely observed to enter parenchyma despite the presence of nonlabeled erythrocytes within the parenchymal structure after irradiation the vascular bed following irradiation increased greatly as the parenchyma diminished to a minimum of less than 10 percent control at 75 hr despite these changes in the architecture of the marrow the average density of labeled cells per area of marrow corresponded to values expected on the assumption of a free flowing circulation the technique used at present did not allow us to distinguish at all times between a free flowing circulation through intact sinusoids or through areas in which the sinusoidal wall as such was destroyed
MED	factors limiting survival after circulatory occlusion under hypothermia and hyperbaric oxygenation thirty minutes of circulatory occlusion with mild hypothermia and hyperbaric oxygen ventilation resulted in a mortality of 83 3 percent in animals when coronary perfusion from a reservoir was added the mortality rate was 22 percent ventricular fibrillation was much more easily reversed after coronary perfusion there was no evidence of brain damage in survivors which leads to the conclusion that the brain tolerates circulatory arrest better than the heart under these conditions
MED	the effect of hypothermia on circulatory reflexes in the human total circulatory occlusion and release result in hemodynamic phenomena which provide an index of integrity of some cardiovascular reflexes these include carotid sinus and aortic baroceptors arteriolar vasomotor tone and venomotor reactivity baroceptor depression appears at a more moderate level of cooling than does the sympathetic vasomotor depression below 28 degrees c both are significantly depressed although probably not totally abolished the level of 28 degrees c is a critical physiological level and may represent an important limit in the clinical use of hypothermia
MED	studies in perfusion hypothermia with special reference to deep hypothermia and circulatory arrest 1 perfusion hypothermia produces large temperature gradients within the body since organs are cooled roughly in proportion to their basal blood flows the difference between the coldest and the warmest portion of the body after 30 minutes of perfusion exceeds 25 c 2 the average body temperature which provides a proper measure of total body cooling may be calculated from the arteriovenous temperature difference and the extracorporeal flow rate 3 true deep hypothermia is not obtainable by reasonable periods of perfusion alone 4 an important rise of core temperatures occurs during circulatory arrest in hypothermia because of relatively high average body temperature 5 high average body temperatures lead to continuing production of lactic acid in muscle tissue whereas low core temperatures impair lactic acid metabolism thus metabolic acidosis is progressive in prolonged perfusion hypothermia and is accentuated by total circulatory arrest progressive acidosis may be minimized by uniform profound cooling by combining external with perfusion hypothermia 6 diluents appear to have little effect on total body heat exchange during perfusion cooling 7 perfusion warming has a differentially greater effect on core organs though these are readily brought to a normal range much of the animal may remain cold
MED	application of the emission spectrograph to the analytical needs of the industrial hygiene laboratory examples of unique applications of the principles of emission spectroscopy to industrial hygiene problems are provided a discussion of qualitative semiquantitative and quantitative methods of spectrographic analysis is presented these methods include representative applications which are made for the analysis of the metallic constituents of body tissues and fluids from human and animal subjects industrial process materials ores and environmental dusts and fumes brief descriptions of sample preparation techniques required for successful analyses are also presented
MED	nickel carbonyl its detection and potential for formation recent recommendations for control of nickel carbonyl exposures have been considered in the design of a simple sensitive field method for sampling nickel carbonyl in air and process gases the method involves collection in dilute aqueous hcl ph adjustment nickel complex development with alpha furildioxime and extraction with chloroform color intensity is compared visually or for greater accuracy spectrophotometrically with liquid standards sensitivities on the order of 0 001 ppm are obtainable a detailed development of the thermodynamics associated with the formation of nickel carbonyl is also presented to show the maximum concentrations of nickel carbonyl that may be formed over a wide range of co concentrations temperatures and pressures
MED	polarographic determination of heavy metals in air samples the polarograph possesses the required sensitivity and specificity to make it the method of choice for analysis for a variety of heavy metals in air two commercial polarographs are compared and both found adequate on the basis of analysis for lead determinations may be made for antimony copper lead cadmium chromium nickel cobalt manganese and others
MED	the inorganic constituents of human teeth and bone examined by x ray emission spectrography x ray emission spectrography has been applied to study of the elemental composition of human teeth enamel dentine and bone the material consisted of eight crushed teeth enamel and dentine powder separated from eighteen teeth and four pieces of buccal cortical mandibular bone the teeth did not have fillings the whole material contained nineteen elements of which the main ones were calcium and phosphorus in all the samples of tooth material there were found ca p cl fe zn sr and k and the bone also contained ni the time needed for a semi quantitative analysis compares very favourably with that needed for other methods
MED	a kinetic study of nickel ii complexes of sulfur containing amino acid the rate expression for the ethylenediaminetetraacetic acid edta ligand exchange reaction with nickel cysteine is rate k complex kedta complex edta this two term rate expression is characteristic of square planar complexes and agrees with the square planar configuration of ni cysteine reported on the basis of spectral studies the edta independent term of the rate expression is an acid catalyzed term and can be written k h complex the value of kn is 2 5 x 10 m sec while the value of kedta is only on the order of 10  10 m sec the edta reaction with ni cysteine methyl ester is very similar to the reaction with ni cysteine when the sulfur containing amino acid ligand contains a thiol ether the kinetic differences are striking ligand exchange reactions of edta triethylenetetramine and diethylenetriamine with nickel methionine complexes are several orders of magnitude faster and give products that are mixed ligand complexes the results of this kinetic study of amino acid complexes containing sulfhydryl and thiol ether sulfur groups support other studies at equilibrium which suggest sulfur coordination and square planar complexes for the sulfhydryl groups and octahedral complexes with no sulfur coordination for thiol ethers
MED	the action of metal ions on tobacco mosaic virus ribonucleic acid added transition metal ions stabilize the secondary structure of tobacco mosaic virus ribonucleic acid tmv rna as evidenced by a reduction in the absorbancy change of heated nucleic acid solutions in spite of this stabilization of secondary structure heating in the presence of metal ions results in the loss of biological activity due to the hydrolysis of phosphodiester bonds thus all heavy metal ions of the iib and first transition elements studied caused a rapid loss of biological activity of tmv rna at ph 6 5 and 65 calcium and magnesium ions while not affecting secondary structure at 65 and ph 8 5 caused a rapid loss of biological activity at ph 5 8 and room temperature lead ions catalyzed the hydrolysis of rna to i 3   mononucleotides on long standing nucleosides were formed
MED	chromium lead cadmium nickel and titanium in mice effect on mortality tumors and tissue levels about 700 mice were given throughout their lives 5 ppm cadmium lead chromium nickel or titanium in drinking water while fed a diet deficient in cadmium and low in other metals tissue concentrations comparable to those of man were observed sex differences appeared mortality of females was unaffected mortality of males on cadmium lead and nickel was increased compared with that of the chromium group and of those on cadmium and lead compared with the controls longevity of the oldest 10 of both sexes was less in lead and titanium groups and of males in cadmium group compared with controls no metal was carcinogenic incidence of tumors in males on cadmium and lead and in females given nickel was decreased body weights at death were greater in titanium chromium and lead groups large increments of titanium moderate increments of cadmium and nickel and lesser increments of chromium and lead were observed in 5 organs compared with controls higher concentrations of cadmium and titanium occurred in younger mice and the other metals did not increase markedly in tissues with age all metals except chromium exhibited one or more signs of innate toxicity
MED	synergistic effects between antioxidants and selenium or vitamin e several antioxidants when fed to chicks at relatively high levels in an experimental diet were ineffective in preventing the exudates and mortality from a combined deficiency of selenium and vitamin e some of the compounds were toxic as evidenced by sudden death or subcutaneous hemorrhages when amounts of either selenite or a tocopheryl acetate which individually had little or no effect on symptoms were given with the antioxidants signs of deficiency and mortality were prevented and toxicity also was eliminated
MED	the expression of urine analysis results  dash observations on the use of a specific gravity correction urine analyses are very useful for measuring the extent of exposure to certain toxic substances the types of specimen obtainable from persons employed in industry and the effect of concentration variations are discussed in expressing the results of analysis it is shown that a concentration correction is essential the correction based on specific gravity is the easiest to apply the mean specific gravity for persons resident in the u k has been found to be around 1 016 a figure considerably lower than the mean of 1 024 used by many workers particularly in the u s a the implications of this on the results of urine analysis are indicated
MED	activation and inactivation of p hydroxyphenylpyruvate hydroxylase 1 p hydroxyphenylpyruvate hydroxylase ec 1 99 1 14 is reversibly inactivated by dialysis storage purification involving ammonium sulfate fractionation and treatment with oxidizing agents the inactive enzyme is reactivated by various reducing agents 2 metal chelating agents inhibited enzyme activity 1 10  phenanthroline and 4 7 diphenyl 1 10 phenanthroline fe sensitive strongly inhibited but 2 9 dimethyl 1 10 phenanthroline cu specific did not 1 10 phenanthroline treated p hydroxyphenylpyruvate hydroxyl  ase was reactivated specifically by fe in the presence of a reducing agent indicating a role for fe in enzyme activity 3 nonoxidative sulfhydryl reagents did not materially inhibit the enzyme activity under various conditions
MED	responses of b subtilis atcc 558 to streptomycin to observe in detail the influence of streptomycin on the growth of sm dependent type the author chose b subtilis atcc 558 and made experiments on its responses to streptomycin with special reference to the relation of the sm concentration with spore formation of its sm dependent type together with germination and outgrowth of the spores formed the results are as follows 1 among 18x10 cells of wild type of b subtilis atcc 558 about 3 200 cells of sm resistant and one cell of sm dependent are found as its mutant 2 b substilis atcc 558 shows normal growth at sm concentration below 10 r ml but the growth declines rapidly between sm 10 r ml 20 r m l and the growth stops entirely at sm concentration 20 r ml 3 sm resistant type grows well between sm 0 1 r ml sm 2 000 r ml the growth declines rapidly at about sm 10 000 r ml 4 sm dependent type shows normal growth between sm 10 000 r ml 20 r m l the growth get worth below sm 10 r ml and the cell shape elongates several times at sm below 1 r ml each cell becomes filamentous form and has several ten times length of normal cell as if the cells have stopped to divide at low sm concentration 6 the germination and outgrowth of spores of the sm dependent type slow down with decline of sm concentration but the germinated spores grow in normal forms until sm concentration reaches 7 8 r ml then the germination becomes much slower and the cells grow in filamentous forms or irregular forms at extremely low sm concentration both germination and outgrowth nearly stop
MED	phospholipids of the bovine rabbit and human lens the phospholipids of bovine rabbit and human lenses contain cephalin lecithin and sphingomyelin but their distribution differs with each species there is suggestive evidence that there may also be plasmalogen in the lens but if so it represents a minor phospholipid component the fatty acid composition of each phospholipid differs in each species with most of the differences centering around 16 0 18 1 and 24 1
MED	surgical aspects of heart disease in pregnancy the ideal management of the pregnant woman with heart disease is medical if feasible the operative experience with mitral valvulotomy in pregnancy has expanded this procedure is now indicated when progressive cardiac disability develops during the first or second trimester and when the proven dominant lesion is mitral stenosis when other lesions are present especially those requiring pump oxygenator perfusion the risk must be carefully measured damage to the fetus may result from reduced placental blood flow
MED	traumatic lesions of the optic chiasma a report of four cases case histories of four patients who suffered severe head trauma resulting in complete bitemporal hemianopia are presented the optic chiasm was visualized in only one patient it was markedly swollen and disintegrated this appearance was consistent with multiple minute tears of the crossed fibres in the median sagittal plane other theories to explain the bitemporal field defect are discussed
MED	lung cancer an evolutionary approach lung cancer is presented as an example of somatic mutation in contrast to previous theories the following are defined a the major growth controlling mechanism b the mutation found in cancer and c the environmental changes in the lungs of patients who smoke cigarettes which can select this mutant
MED	the effects of electrophoretically separated lens proteins on lens regeneration in diemyctylus viridescens in the present study lenses were removed from the eyes of adult anesthetized newts macerated in 0 03 m borate buffer at ph 8 6 and separated by starch gel electrophoresis upon staining with amido black 10 b seven distinct staining areas appeared in the blocks three bands moved toward the anode and three toward the cathode in addition a seventh moiety represented by a smear of material moved toward the anode one millimeter times five tenths millimeter plugs were removed from each of these areas and were placed into freshly lentectomized eyes plugs from most strongly positive and most weakly negative proteins inhibited lens regeneration in addition plugs from the area containing the weakly negative protein induced either lenses with aberrant polarity or double centered lenses with centers of opposed polarity all other protein bands had no significant effect on regeneration in addition to the above experiments homogenates and proteinasedigested homogenates of lenses were injected into eyes following lentectomy three 5 ul samples were injected in each case over a six day period injection of the plain homogenate stimulated lens regeneration markedly while the proteinase destroyed the stimulatory activity theoretical considerations of the above data are discussed
MED	enzymic synthesis of deoxyribonucleic acid xviii the repair of partially single stranded dna templates by dna polymerase a partially single stranded dna prepared by limited digestion of each strand with exonuclease iii can be restored to its native fully double stranded structure by escherichia coli dna polymerase the rate of synthesis observed in the repair of such a partially degraded primer in the polymerase system is faster than that seen with a native dna the newly synthesized dna is covalently attached to the primer the fully repaired dna resembles the original native dna as judged by its appearance in electron micrographs cscl density gradient analysis denaturability and genetic activity dna synthesis which follows the repair phase produces a structure that is not covalently linked to the primer and resembles in its nondenaturability branched appearance and lack of genetic activity the product obtained with a native dna primer schildkraut richardson kornberg 1964
MED	on the mechanism of genetic recombination in transforming bacillus subtilis the molecular fate of transforming dna in competent bacillus subtilis has been studied the physical differentiation of transforming dna and the genetic material of recipient bacteria was effected by employing the isotopes n and p competent bacteria labeled with n and p were allowed to incorporate n p labeled transforming dna intracellularly dna was isolated from these recipient cells and centrifuged in cesium chloride analysis of drop fractions collected at equilibrium showed the presence of radioactivity in a region of density corresponding to recipient dna material contribution from donor dna to the resident dna did not occur when genetically inert bacillus cereus dna was substituted for homologous dna it was concluded that radioactivity appearing in the unlabeled resident dna was not the result of degradation of input p dna and subsequent incorporation by normal metabolic processes since single stranded dna of donor origin was not detected nor was there evidence for the non specific aggregation of donor and recipient dna it was concluded that the observed physical association of transforming and recipient dna occurs as a result of genetic recombination in transformed b subtilis
MED	physical and biological studies on transforming dna bacillus subtilis transforming dna prepared by the method described has an average molecular weight of 11 6 million the dna is heterogeneous as judged by chemical composition thermo spectral and pyenographic properties these properties have been used to fractionate some of the biologically active molecules which show higher specific activities in transforming respective auxotrophs
MED	comparison of mutation and inactivation rates induced in bacteriophage and transforming dna by various mutagens inactivation and mutation rates were measured for t4 phages and bacillus subtilis transforming dna treated by low ph nitrous acid or hydroxylamine at different temperatures the frequency of mutants increased linearly with time for all three agents whereas the logarithm of survival gave a linear plot only for nitrous acid and low ph an arrhenius plot showed the same slopes for both inactivation and mutation rates after treatment with low ph or nitrous acid for the latter agent the slope remained unaltered even when the dna was treated in the denaturated state in contrast mutation rates obtained after the exposure to hydroxylamine differed greatly for native or denatured dna phage t4 being intermediate treatment by low ph or nitrous acid interrupted the genetic linkage between tryptophan and histidine the interrupting hits being about 1 3 as frequent as lethal hits independent of the temperature
MED	autolysis of bacillus subtilis by glucose depletion in cultures in minimal medium rapid lysis of cells of bacillus subtilis was observed as soon as the carbon source e g glucose had been completely consumed the cells died and ultraviolet absorbing material was excreted in the medium the results suggest that the cells lyse because of the presence of autolytic enzymes in the presence of glucose the damage to the cell wall caused by these enzymes is repaired immediately
MED	plasma 17 hydroxycorticosteroids and 17 oxosteroids in patients with breast cancer and in normal women 1 17 hydroxycorticosteroids 17 ohcs and 17 oxosteroids were measured in the plasma of normal women patients with early breast cancer and in patients with advanced metastatic disease 2 the mean plasma 17 ohcs level was found to be normal in the early stages of the disease but was raised in the advanced disease in both groups of patients the variance was significantly greater than in normal women 3 the mean plasma 17 oxosteroid level in both early and advanced breast cancer was not significantly different from the normal level but the variance was increased 4 there is a significant correlation between the plasma 17 ohcs and 17 oxosteroids in normal women which was not found in the cancer patients 5 in patients with advanced breast cancer the levels of plasma 17  oxosteroids were significantly correlated with the amounts of 11 deoxy  17 oxosteroids found in the urine there was no correlation between plasma and urinary 17 ohcs 6 the physiological significance of these findings is discussed
MED	hormone therapy in metastatic breast cancer clinical response and urinary gonadotrophins the total urinary gonadotrophin output of a group of post menopausal women with metastatic breast carcinoma undergoing hormone therapy which in every case initially consisted of treatment with diethylstilboestrol des ca 20 mg d has been studied for periods varying from seven months to 31 2 years no correlation between gonadotrophin output and clinical response was found except that in all cases showing objective regression urinary gonadotrophin remained low throughout the remission period a low level of gonadotrophin output was not however necessarily indicative of a good clinical remission following withdrawal of des and independent of the period of therapy recovery to pre treatment levels was the rule rather than the exception a small group of patients maintained on a lower dose of des 3 5 mg d showed the same degree of suppression of urinary output as those receiving 20 mg d and several of these exhibited objective remissions the study has emphasised the importance of site specificity in the response to hormone therapy and underlines the difficulties of relating the clinical response of the patient as a whole to changes in hormonal environment
MED	plasma androgens in women i normal and non hirsute females oophorectomized and adrenalectomized patients 1 in a group of 20 normal non hirsute females age 17 to 38 18 non  hirsute patients with varied genito urinary disorders 8 oophorectomized and or adrenalectomized patients plasma testosterone was measured by the method of finkelstein et al 1961 conjugated androsterone and conjugated dhea were determined by a modified method of migeon plager 1955 2 mean baseline values in normal females were 11 06 ug 100 ml testosterone 11 8 5 5 ug 100 ml conjugated androsterone and 29 5 15 5 ug 100 ml conjugated dhea no significant response to hcg could be seen dexamethasone affected the conjugated dhea significantly but did not seem to affect conjugated androsterone or testosterone 3 the non hirsute patients showed essentially the same pattern an effect of dexamethasone on the levels of conjugated androsterone was demonstrated 4 oophorectomized women had baseline values for the conjugates in the range of normals testosterone however was low with an average of 016 ug 100 ml in the adrenalectomized patients no androgens were detectable
MED	oophorectomy and cortisone treatment as a method of eliminating oestrogen production in patients with breast cancer the urinary excretion of oestrone oestradiol 17b oestriol and 17  hydroxycorticosteroids has been estimated in 55 premenopausal and 91 postmenopausal women with breast cancer at various stages of the disease before therapy the depletion of oestrogen excretion caused by oophorectomy combined with cortisone treatment was studied in the patients with metastasising breast tumours 32 premenopausal and 56 postmenopausal subjects patients with disseminating breast cancer excreted significantly larger quantities of oestriol than healthy women of the same age whether pre  or postmenopausal the excretion of oestrone and oestradiol 17b was similar in cancer patients and healthy women of corresponding age oophorectomy reduced the oestrogen excretion not only in premenopausal subjects but also in quite a number of postmenopausal patients particularly in those who were still excreting significant amounts of oestrogens this decrease in the oestrogen output was transient and was followed by a compensatory increase possibly of adrenal origin cortisone administered within a month after the oophorectomy at a dosage of 50 mg per day rapidly depressed the secondary rise in the oestrogen output to a level of about 4 to 5 ug 24 h irrespective of the age of the patient this excretion level was unchanged as long as cortisone was given in an adequate dose but increased rapidly when the cortisone treatment was discontinued oophorectomy combined with adequate cortisone treatment seems to offer an alternative to the extensive surgical porcedures undertaken to eliminate oestrogen production in breast cancer patients
MED	some reactions of cytotoxic antibodies against previously unknown mouse isoantigens the antiserum produced in c3h he against c3h st lymphosarcoma 6c3hed contains a mixture of at least two antibodies of different properties and specificities anti h 5a is a hemagglutinating antibody removed by absorption with red cells and many tissues anti v is a cytotoxin reacting with c3h st tissue and 6c3hed but not with red cells the reciprocal antiserum c3h st anti c3h he sarcoma mc1m is more complex it contains the hemagglutinin anti h 6a and a variety of cytotoxins one appears to be specific for c3h he tissues and the tumor mc1m another reacts with antigens on the c3h go carcinoma bp8 two additional cytotoxins may also be present immunization between sublines of the same inbred strain can result in the production of a variety of antibodies directed against unrelated antigens present on even long transplanted cells the significance of
MED	on the value of thymectomy in adult mice as a means of potentiating the immunosuppressive action of melphalan l phenylalanine mustard thymectomy has been found to be ineffective as a means of potentiating the immunosuppressive action of melphalan in adult cba p mice challenged with a strain mammary carcinoma transplants this was true when the thymectomy was performed 2 days 4 weeks or 7 weeks prior to injection of a single dose 15 mg kg body weight of melphalan administered 24 hours prior to tumour transplantation and also when thymectomy was combined with multiple doses of melphalan given before and after tumour transplantation these findings are discussed
MED	studies on the kinetics of transplantation immunity using the parameter of the number of tumor cells necessary to produce s c tumors in allogeneic animals at varying intervals after antigenic stimulation immunity was found to be in force as early as 2 days after primary antigenic stimulation it reached a peak at 8 10 days and had largely subsided by the end of a month this method was also applied to the quantitative study of the onset degree and duration of immunity elicited by skin grafts the results obtained with inocula of large numbers of tumor cells 10 percent were comparable to those obtained with massive skin grafts the differences in the degree of antigenic stimulation resulting from different routes of inoculation were studied it was found that the intradermal i d route of inoculation resulted in a more intense antigenic stimulation than the s c route when both routes of inoculation were used simultaneously the pattern of growth of the s c tumor was influenced by the i d inoculation an i d inoculum given 24 or 48 hr earlier caused marked suppression of growth of the s c tumor while when an i d inoculation was preceded by an s c inoculation although there was an appreciable effect on the growth size the growth curves of the 2 tumors were always parallel there was no correlation between cytotoxic activity and the degree of immunity in force at a given time
MED	evidence for an immunological reaction of the host directed against its own actively growing primary tumor cells isolated from primary benzo a pyrene induced fibrosarcomas in rats of a pure line were tested for their ability to grow as autografts when injected back into the autochthonous host the autograft did not take if the primary tumor had been removed but grew occasionally in animals in which the major part of the tumor was left in every instance the sarcoma cells grew when injected into syngeneic recipients in these recipients the growth of the sarcoma cells was prevented or retarded when they were mixed in vitro prior to injection with spleen cells from animals that had been immunized against the tumor autochthonous spleen cells taken from the animal with the tumor behaved in this test like those from immunized animals as long as the spleen was taken 3 weeks after removal of the tumor when the spleen and tumor were removed at the same time however autochthonous spleen cells did not behave like spleen cells from immunized animals and did not interfere with the growth of the tumor the results of both the autograft and spleen cell experiments suggest that rats react actively against their own growing primary tumors but that the tumor exhausts the supply of lymphocytes responsible for this reaction after the tumor is removed the concentration of antitumor lymphocytes in the spleen builds up and the animals can reject an autograft  j nat cancer inst 36 29 35 1966
MED	a comparison of the cytologic effects of leurosine methiodide and vinblastine in tissue culture comparison of the degree and duration of arrest of metaphases in tissue culture cells by leurosine methiodide and vinblastine was made colchicine and demecolcine were included for reference purposes all four drugs produced a similar cytologic effect but vinblastine was most active and remained active for the longest period of time
MED	comparison of central aortic and peripheral artery pressure curves brachial artery and central aortic pressures were compared in 50 consecutive patients subjected to retrograde left heart catheterization in order to re emphasize the fact that the two pressures are not necessarily identical in 43 cases the systemic systolic pressure peaks exceeded those in the central aorta while in seven these pressures were equal the average pressure difference was 22 6 mm hg the greatest differences occurred in cases of aortic regurgitation and could be extreme the brachial artery systolic pressure exceeding that in the aorta by more than 100 mm hg in some instances the least differences occurred in cases of aortic stenosis but significant differences occasionally existed leading to erroneous estimation of valve orifice size if the systemic rather than the aortic systolic pressure was used
MED	changes in sphingosine and fatty acid components of the gangliosides in developing rat and human brain rat brain increases in weight after birth in three stages i rapidly for the first 2 weeks ii at a lower rate from 2 to 5 weeks and iii at a still lower rate from 5 weeks to 5 months during the succeeding period designated iv it maintains constant weight up to 1 year of age brain ganglioside content increased linearly during i and ii more slowly during iii and diminished during iv the appearance of measurable amounts of brain sphingomyelin and cerebroside succeeded that of ganglioside ceramide with c  sphingosine and c fatty acid was found in a large proportion of all three sphingolipids upon their first appearance in measurable quantity c fatty acid in cerebroside rapidly declined to a negligible level while in gangliosides and sphingomyelin it declined slowly but remained the major fatty acid component cerebrosides and sphingomyelin contained c  sphingosine almost exclusively at all stages of rat brain growth gangliosides contained c  sphingosine almost exclusively at birth but subsequently accumulated c  sphingosine until they had nearly equal quantities of each base type changes in human brain gangliosides resemble those in rat in tay sachs disease gangliosides have c  sphingosine predominantly and a high content of c fatty acid
MED	studies of the generalized shwartzman reaction induced by diet vi effects of pregnancy on lipid composition of serum and tissues pregnancy induced profound alterations in the lipid composition of serum and tissues 1 there is an elevation of total serum lipid phospholipid triglyceride free fatty acid and cholesterol 2 while the total lipid of the liver and kidney are increased that of the depot fat is decreased 3 palmitate and oleate are increased in serum and liver 4 arachidonate and stearate are decreased in serum and liver and 5 placentas contain more stearate than the other organs of the pregnant rat and also have a higher water content the decrease in depot total fat elevation of serum liver and kidney total fat and elevation of serum free fatty acids suggest that pregnancy induced mobilization of depot fat the increase in proportion of liver and serum palmitate suggests that pregnancy induces increased lipogenesis from the acetate pool the appearance of an increased amount of long chain fatty acids in the liver may be due to the increased intake of dietary fat the decrease in arachidonate and stearate in serum and liver suggests a relative decrease in mitochondrial fatty acid synthesis
MED	electron microscopy of the bovine lung the normal blood air barrier lungs of 20 healthy mature cattle were fixed in oso embedded in a polyester resin and studied via electron microscopy the blood air barrier was widely variable in thickness and consistency there was a continuous epithelial alveolar lining the cytoplasm of some of the epithelial cells contained membrane bound aggregates of granules which may be secretory structures the epithelium rested on a basement membrane which in turn was continuous with or rested on an adjacent capillary endothelial basement membrane or continued into merging connective tissue the capillary endothelium was not fenestrated it was a continuous cellular membrane both the epithelium and endothelium contained numerous caveolae and pinocytotic vesicles cells of the alveolar wall included fibroblasts lymphocytes macrophages and an occasional mast cell very little elastin was observed
MED	a sensitive and specific fluorescence assay for tissue serotonin a sensitive and specific method for the estimation of serotonin in biological materials is described in this method serotonin is reacted with ninhydrin to form a product whose fluorescence is eight times more intense than the native fluorescence of serotonin in strong acid solution with this method it is possible to measure serotonin in organs in which endogenous serotonin had not been previously detected and to study the subcellular distribution of this amine in the rat pineal and adrenal glands
MED	effects of ruminal insufflation on cerebral circulation and metabolism in the goat the effects of nitrogen insufflation of the cannulated rumen were studied in 10 goats parameters which were measured included cerebral blood flow mean carotid arterial pressure pressure in the confluence of sinuses cerebrospinal fluid pressure blood oxygen and carbon dioxide contents packed cell volume pcv and hemoglobin concentration values for cerebrovascular resistance and cerebral o utilization were calculated increased ruminal pressure had little effect on cerebral blood flow and cerebrovascular resistance cerebral o utilization was decreased when the intraruminal pressure was increased this decrease was caused by a reduction in arterial o content and a consequent decrease in cerebral arteriovenous o difference mean arterial venous sinus and cerebrospinal fluid pressures were increased as the intraruminal pressure was increased increases in pcv and hemoglobin concentration were not related to the elevated intraruminal pressure central nervous system signs in goats with acute ruminal tympany may be caused by cerebral hypoxia the nature of the hypertensive changes associated with increased ruminal pressure were demonstrated but due to the influence of multiple factors on fluid compartments no conclusions could be made about the mechanism of these pressure responses mechanical factors however may be involved
MED	a comparison between inhaled dust and the dust recovered from human lungs experiments on the loss of dust particles during breathing indicate total deposition in the respiratory tract subjection of the results to qualitative arguments may give information about alveolar deposition measurements of insoluble dust recovered post mortem from human lungs give the absolute retention of dust which was deposited in the alveoli and subsequently shifted probably to a large extent to the lymphatic vessels of the lungs experimental results for total deposition and absolute retention are discussed in connection with the health risk due to inhaling insoluble particles such as plutonium dioxide
MED	dual cation activation of bovine lens autolysis the autolytic activity of bovine lens extracts at 55 c and ph 7 4 has been shown to be markedly influenced by the simultaneous presence of mono  and divalent cations of the cations tested na at 2 5 to 5 mm and mg at 5 to 10 mm produce the best activation the stimulation is synergistic on the basis of results obtained here and in other laboratories the suggestion is made that this combination of cations may be required for activation of the neutral proteinase of the lens in the presence of mg and average physiologic lenticular levels of both na and k autolysis is suppressed to the basal level obtainable in the presence of mg alone
MED	nucleic acid metabolism in the lens iii effect of x radiation a previous communication reported an increased in vivo incorporation of p 32 into the albuminoid rna fraction of the rat lens 6 hours after the animal had been exposed to x radiation 1 500 r in the present study the in vitro uptake of p 32 and c 14 adenine by albuminoid ribosomal and soluble rna fractions of normal and x  irradiated rat lenses was measured the rna fractions were extracted by sodium dodecyl sulfate in 0 9 per cent nacl the specific rna fractions were also hydrolyzed chromatographed on paper and the activity of the individual nucleotides as well as the specific rna fractions was determined an experiment was also performed in which the capsules were removed after the 3 hour incubation period and the activities determined in the nucleic acids extracted from the capsules and in the three rna fractions of the remaining lens matter the results of these experiments indicate that the incorporation of p 32 and c 14 adenine into albuminoid rna was markedly stimulated 1 hour after 1 500 r whole body radiation there was no significant effect on ribosomal or soluble fractions the effect of formaldehyde and heating on x irradiated albuminoid rna was much less than on the albuminoid rna derived from control animals
MED	changes in dna rna and protein synthesis in the developing lens lens cell dna rna and protein synthesis in the developing mouse eye were studied with the use of tritium labeled thymidine uridine and l  leucine and autoradiographic techniques in the mouse embryonic lens epithelial cells undergoing dna synthesis were found over the entire anterior lens surface from birth and until the eyes opened the percentage of epithelial cells undergoing dna synthesis rapidly decreased later the percentage of epithelial cells undergoing dna synthesis was nearly constant as the germinative zone became localized in the lens equator region rna synthesis occurred in all nucleated cells of the developing lens from the embryonic stage until the eyelids opened with lens maturity the h uridine was incorporated into the rna of only the more superficial cells a similar pattern of tritium incorporation was seen with h l leucine
MED	amino acid transport in the lens in relation to sugar cataracts the steady state distribution of free amino acids between the lens and aqueous humor is significantly reduced in diabetic rabbits and also in rats fed rations containing high concentrations of xylose or galactose the reduction in the level of amino acids in the lens is apparently a direct effect of the high concentration of sugars but it is doubtful whether it is related to cataract formation
MED	visco elastic properties of the lens the dynamic visco elastic properties of human monkey and rabbit lenses have been measured with a dynamic rheometer the value for the apparent elastic modulus young modulus of the lens was found to be 10  10 dyne cm in humans and 10  10 dyne cm in monkeys and rabbits the value for the loss tangent was 0 3 0 4 in the human lens and 0 3 0 6 in rabbit and monkey lenses elastic moduli and loss tangents of the lenses showed poor dependence on temperature at 15  55 c and on frequency of oscillation at 0 01 25 c s the lenses showed linear visco elasticity when the amplitude of oscillation was below 0 02 mm and they showed nonlinear visco  elasticity when the amplitude exceeded 0 03 mm
MED	carbonic anhydrase distribution in rabbit lens the distribution of carbonic anhydrase activity in the mature rabbit lens was determined the activities in nucleus cortex epithelium with anterior capsule anterior capsule and posterior capsule were respectively 2484 256 1571 87 545 93 159 39 and 65 49 moles co kg wet tissue wt per hr at 0 c it was concluded on the basis of the available evidence that carbonic anhydrase cannot play a primary role in the cation transport system of the lens
MED	changes in weight and adenosine triphosphate content in the lens of the xylose fed rat xylitol and sorbitol accumulated in the lens of the xylose fed rat two days before loss of adenosine triphosphate and cataractous changes were apparent the maximum degree of cataract occurred when the level of the polyols was at its highest regression of cataract was accompanied by decrease in polyol concentration and restoration of the level of atp the lens of the xylose fed rat did not usually increase in weight
MED	identification of species specific and organ specific antigens in lens proteins the species specific and organ specific antigens of lens were investigated by gel diffusion and immunoelectrophoresis techniques it was found that rabbit antiserum to bovine lens showed cross reaction with other bovine tissues these cross reacting antigens were the b    and y crystallins there were two major and a minor organ specific antigen in lens both the major antigens had a mobility and were identified as the a crystallin of lens
MED	an electron microscopic study of wolffian lens regeneration in the adult newt changes in the morphology of cells during the regenerative tissue transformation of the pigmented epithelium of the iris into lens in the adult newt triturus viridescens were studied in ultrathin sections using the electron microscope in addition quantitative analyses with electron micrographs were performed the cells of the normal iris are characterized by an abundance of melanin granules an extensive smooth   surfaced endoplasmic reticulum and irregular indentations of the nuclear membrane after lens removal the first visible changes are detected in nuclei of the mediodorsal iris cells and involve an increase in the number of primary nucleoli later the nuclei enlarge and become spherical and prominent nucleoli appear these nucleoli can be distinguished from the normal nucleoli by the presence of the granular cortex surrounding the fibrous core the pigment granules seem to be completely extruded into the intercellular spaces and subsequently taken up by leucocytes the endoplasmic reticulum disintegrates gradually and finally almost disappears there is a significant increase of ribosomes in the cytoplasm later the cytoplasmic matrix also acquires fibrous elements about 50 a wide of low density probably corresponding in nature to the main components of a normal lens cell these and other changes in the transforming cells are discussed
MED	growth of several human cell lines in newborn rats when injected intravenously into newborn rats eight human tissue cultured cancer cell lines  dash h ep 2 detroit 6 j 111 rp 41 rp 212 adeno cx 1 ovary 2 and mac 21  dash grew progressively in lung and other organs of more than 50 per cent of the animals and commonly caused death after 5 8 weeks two other human cell lines  dash the carcinoma h ep 1 and the presumably normal amnion b  dash grew less frequently and rarely caused death or illness
MED	the human tumor egg host system iii tumor inhibitory properties of tenuazonic acid the fermented broth of a culture of alternaria tenuis auct inhibited the growth of the human adenocarcinoma h ad 1 in the embryonated egg with the aid of studies in the egg tumor system the active agent was isolated and identified as tenuazonic acid tenuazonic acid was produced by a number of alternaria isolates and by an aspergillustamarii and a phoma sp compared with tenuazonic acid on a molar basis about 20 times as much hadacidin or 6 mercaptopurine 2 times as much azaserine but only 1 20 as much triethylenemelamine tem were required to achieve the same inhibition of h ad 1 tumor growth in the egg tenuazonic acid was more effective against h ad 1 than against another transplantable human tumor a 42 tenuazonic acid compared with puromycin more specifically inhibited tumor growth in the egg tumor system
MED	the occurrence of biologic crystals in tumor and nontumor cultures of c3h hej mice crystalline structures of various types have been found in primary tissue cultures of neoplastic and non neoplastic tissues from c3h hej mice all of the cultures of mammary carcinoma tissue contained the crystals the crystals were found in varying incidence in the cultures of several other tissues with the exception of those from the kidney a dialysis compartment was not essential for the formation of the crystals the development of the crystals was accelerated by a modification of the culture medium
MED	a comparison of the fine structure of cultured mac 21 and hela cell the fine structure of a cultured mucoid adenocarcinoma cell of human lung mac 21 is described and compared with the fine structure of the hela cell the differences in fine structure between the two strains are primarily quantitative the mac 21 cell differed however in the following respects a spindle shaped cell with larger nucleus and increased nuclear membrane invaginations and considerably larger amounts of perinuclear golgi apparatus the cytoplasm contained areas of low density undefined by a limiting membrane which are thought to be accumulations of mucin the two cell strains contained numerous multivesicular bodies some with lamellae in various stages of development suggesting that these organelles may be involved in the formation of the lipide rich myelinated structures observed in both hela and mac 21 cells the number of myelinated bodies was found to be inversely proportional to the ph of the medium
MED	effect of parathyroid and other human tumors and tissues on bone resorption in tissue culture mouse calvaria were grown in tissue culture in combination with single or multiple fragments of a variety of human tumors and glandular tissues to determine their capacity to enhance bone resorption single fragments of parathyroid adenoma tissue consistently enhanced resorption in both the frontal and the parietal bones except for one squamous   cell carcinoma of the lung which had some activity all other tissues tested as single fragments had no enhancing effect on the other hand all human tissues enhanced resorption when multiple fragments were placed in a halo around the calvarium suggesting the presence of lesser amounts of resorption enhancing factors in other human tissues
MED	limited growth period of human lung cell lines transformed by simian virus 40 summary  infection of human cell strains with simian virus 40 induced virus replication and cell transformation with the changes in morphology and cytology described by previous investigators although transformation greatly enhanced growth potentials of the strains only 2 of 23 transformed cultures appear to have attained autonomous growth   j nat cancer inst 33 227 236 1964
MED	bacteriophages that lyse mycobacteria and corynebacteria and show cytopathogenic effect on tissue cultures of renal cells of cercopithecus aethiops a preliminary communication bacteriophages isolated from sputum and resection specimens of pa  tients suffering from carcinoma of the lung were found to lyse coryne  bacteria and mycobacteria and to produce a cytopathogenic effect on certain cells in tissue cultures from the same and other patients with neoplastic disease bacteria were isolated and described as coryne my  cobacteria because of bacteriological features they shared with both species these bacteria which either were sensitive to mycobacterio  phages and corynebacteriophages or were phage immune lysogenic bacteria could be induced to produce lytic particles with phagolytic activity on corynebacteria and mycobacteria and a cytopathogenic effect on hela cells and on the renal cells of cercopithecus
MED	gel filtration of the soluble proteins from normal and cataractous human lenses the soluble proteins of normal and cataractous lenses were separated according to their molecular size on the polysaccharide gel sephadex g 100 in cataractous as well as in normal lenses 4 different compo  nents were obtained during the evolution of cataract there is a pre  ferential decrease of the low molecular weight proteins of the lens these disappeared completely in mature and hypermature cataract on the other hand the proteins of high molecular weight e g  crystallin are very resistant to the pathological process the electrophoretic pattern of the low molecular weight proteins in the normal lens revea  led several fractions distributed over a large mobility area after immunoelectrophoresis 3 different precipitin lines were obtained
MED	the insoluble proteins of bovine crystalline lens the insoluble lens proteins the albuminoids of the adult bovine lens cortex can be rendered soluble by raising the ph of their washed suspension in 0 9 nacl to 10 5 and then reducing it again to ph 7 4 the sedimentation constant of the dissolved protein is 10 8 s its molecular weight is estimated to be 360 000 12 000 the amino acid composition is approximately the same as that of the soluble  crysta  llin fraction a kinship which is also apparent from their immunochemi  cal properties it is suggested that the initial insoluble protein is a molecular aggregate of  crystallin which is dissociated in alkaline solutions to molecules exhibiting a sedimentation constant of 10 8 s
MED	glucose 6 phosphate dehydrogenase and 6 phosphogluconate dehydrogenase in lens and blood of different species the activities of glucose 6 phosphate and 6 phosphogluconate dehydro  genase were measured in the lens and erythrocytes of man and several other species there is a wide variation between individuals of the same species but there seemed no correlation between the activity of either enzyme in the lens and their activity in the erythrocytes of the same species there is a wide range of activity of both glucose 6 phos  phate dehydrogenase and 6 phosphogluconate dehydrogenase in the lens and in the blood of different species several species had glucose 6 phos  phate dehydrogenase activity in erythrocytes below the level considered deficient in man the sorbitol content of the lens was not correla  ted with glucose 6 phosphate dehydrogenase activity
MED	nucleic acid metabolism in the lens iii effect of x radiation a previous communication reported an increased in vivo incorporation of p 32 into the albuminoid rna fraction of the rat lens 6 hours after the animal had been exposed to x radiation 1 500 r in the present stody the in vitro uptake of p 32 and c 14 adenine by albuminoid ribosomal and soluble rna fractions of normal and x irradiated rat lenses was measured the rna fractions were extracted by sodium dodecyl sulfate in 0 9 per cent nacl the specific rna fractions were also hydrolyzed chromatographed on paper and the ac  tivity of the individual nucleotides as well as the specific rna frac  tions was determined an experiment was also performed in which the capsules were removed after the 3 hour incubation period and the activities determined in the nucleic acids extracted from the capsules and in the three rna fractions of the remaining lens matter the results of these experiments indicate that the incorporation of p 32 and c 14 adenine into albuminoid rna was markedly stimulated 1 hour after 1 500 r whole body radiation there was no significant effect on ribosomal or soluble fractions the effect of formaldehyde and heating on x irradiated albuminoid rna was much less than on the albuminoid rna derived from control animals
MED	an investigation of mitotic control in the rabbit lens epithelium a water soluble substance which inhibits mitosis in the rabbit lens epithelium has been found to be present in young and old rabbit lenses it has a high molecular weight and is relatively stable at room tempera  ture the inhibitory factor is associated with the y crystallin frac  tion and exists throughout the young lens although the activity in the nuclear region on a wet weight basis is less than half that of the cortex and epithelium
MED	the identification of lysosomal enzymes in bovine lens epithelium biochemical studies are described for the isolation of lysosomes identified as such by the activities of their enzymes in the cells of the bovine lens epithelium the various fractions assayed for lysosomal enzymes showed contamination of mitochondrial and soluble cytoplasmic material in the two isolation procedures employed
MED	protein synthesis and polyribosomes in the calf lens a cell free system capable of incorporating amino acid into protein has been isolated from calf lens polyribosomes have been shown to be present in the ribosomal fraction and to be responsible for most of the protein synthesizing capacity of this fraction the polyribosomes have been examined by electron microscopy and appear to be composed of long strands of ribonucleic acid ranging from 7 000 a to 20 000 a and con  taining a large number of ribosomes with an average diameter of about 140 a
MED	measurement of oxygen tensions in cerebral tissues of rats exposed to high pressures of oxygen brain and cerebrospinal oxygen tensions have been measured in rats breathing air or in various high pressures of oxygen ohp addition of 5 percent co2 to the inspired oxygen raised cerebral oxygen tensions when rats were exposed to 2 atm abs or above inhibition of 75 hemoglobin saturation by para aminopropriophenone lowered cerebral po in rats breathing air but not in rats exposed to ohp the rate of rise of cerebral po to a steady level after rapid compression was found to be faster than the rate of fall to a steady level following decompression addition of co to the inspired gas mixture increased the rate of rise of cerebral po the anesthetics urethane and pentobarbital sodium did not affect cerebral po in rats breathing air or oxygen at 4 atm the results are discussed in relation to factors contributing to oxygen poisoning at high pressures
MED	release of free fatty acids from adipose tissue obtained from newborn infants summary the role played by mobilization of free fatty acids ffa from adipose tissue in producing the typically high serum ffa levels of human infants has been studied ffa concentrations in the serum and subcuta  neous adipose tissue from the gluteal region were determined during postnatal development a maximum level was reached within 24 hr after birth after which there was a gradual fall in serum the ffa level at the end of 12 months was still higher than that in adults while the ffa level in adipose tissue was lower at 3 months than in adults incubation of small pieces of adipose tissue in krebs ringer phosphate buffer containing 4 albumin led to release of ffa into the medium this release could be suppressed by the addition of glucose 200 mg 100 ml for tissue from all age groups except the youngest 0 15 hr after birth
MED	detection of pericardial effusion by radioisotope heart scanning a marked difference between the cardiac silhouette on the six foot chest roentgenogram and the cardiac blood pool determined by radioiso  tope scanning has been shown to be consistent with pericardial effusion and or thickening it has also been observed that the cardiac blood pool is separated from the liver margin by the interposition of peri  cardial fluid and or thickening this separation was not demonstrated in the presence of a normal pericardium to appreciate these features 400 c of radioiodinated human serum albumin and 50 c of colloidal radiogold were used for scanning the former outlined the blood pool and the latter demonstrated the position of the liver
MED	on the mechanism of erythropoietin induced differentiation iv some characteristics of erythropoietin action on hemoglobin synthesis in marrow cell culture some of the characteristics of the erythropoietin stimulation of hemo  globin synthesis by rat marrow cells in culture have been studied the relationship between cell number and rate of hemoglobin synthesis at va  rious levels of erythropoietin is sigmoid rather than linear suggesting a cooperative action among the sensitive cells the magnitude of the erythropoietin effect on the cells increases with time of contact with the hormone at the time of one half maximal effect there is no discer  nible loss of erythropoietin from the culture medium a previously des  cribed lag time in the response to erythropoietin appears to be largely due to the conditions of culture and disappears when the cells are pre   incubated for 9 h replacement of a large fraction of the medium at 24 h intervals enabled the cells to continue hemoglobin synthesis for an additional 24 h
MED	the occurrence of megakaryocytes in the peripheral blood of dogs a study of megakaryocytes in buffy coat smears from 26 dogs revealed that no unusual characteristics were consistently associated with appea  rance of megakaryocytes in the peripheral blood
MED	moderate hypothermia in man haemodynamic and metabolic effects studies were performed on four patients undergoing intracranial opera  tion during the induction and reversal of surface hypothermia to 30 c oxygen uptake decreased an average of 26 per cent from 34 to 30 c to a mean value of 48 per cent of predicted basal uptake at the same time cardiac output decreased only 11 5 per cent resulting in a consistent rise in calculated mixed venous oxygen saturation from a mean of 76 to 81 per cent at 30 c as a result of this and the effect of cooling on oxygen dissociation the estimated tension of oxygen in mixed venous blood remained virtually unchanged when shivering was allowed to occur in two patients oxygen uptake increased approximately 50 per cent without any concomitant increase in cardiac output observed right atrial and svc oxygen saturations correlated well with calculated mixed venous oxygen saturations with regard to direction and magnitude of change with change in temperature
MED	the spectrum of lupus nephritis fifty cases of sle have been collected over a ten year period and the incidence and clinical picture of ln reviewed in the light of other published data lupus nephritis like sle has a variable pattern of its own with a wide spectrum of renal involvement  dash evaluation of therapy and prognosis will have to be conducted against this background lupus nephritis may present as a renal syndrome only without any of the other manifestations of sle renal involvement in sle is common but this does not necessarily indicate a poor short term prognosis in the peter bent brigham hospital series a sustained raised blood pressure and the onset of renal insufficiency influenced the prognosis adversely
MED	comparison of ultraviolet sensitivity of bacillus subtilis bacteriophage spo2 and its infectious dna deoxyribonucleic acid extracted from a clear plaque mutant of the temperate phage spo2 was infectious when incubated with competent cultures of bacillus subtilis 168 m the relationship between numbers of infectious centers and dna concentration was linear the sensitivity of the infectious dna to ultraviolet light was much greater than that of the free phage when b subtilis 168 m was used as host acriflavin which inhibits host cell reactivation increased the rate of ultraviolet inactivation of the free phage so that it approached the inactivation rate of the phage dna acriflavin had little effect on the survival curves of the infectious dna non host reactivating mutants hcr of b subtilis 168 m were isolated the survival curves of spo2 phage were much steeper when the hcr mutant was used as a host than those obtained when the hcr parental strain was used as a host ultraviolet sensitivity of the phage dna was still greater than that of the free phage even when b subtilis hcr was used as host but the difference in sensitivity was much less than the difference obtained with b subtilis hcr as a host possible explanations for the greater ultraviolet sensitivity of the infectious dna are discussed
MED	the isolation and morphology of some new bacteriophages specific for bacillus and acetobacter species the best natural habitat for bacteriophages is probably a semi solid medium containing actively dividing host bacteria such conditions are provided for bacillus and acetobacter species in rotting grass and apples respectively the bacillus phages found included one with a large head and a contractile tail and also a so called killer particle which had a 350 a head and a long contractile tail this particle had the property of killing but not multiplying within a sensitive cell a new morphological type of virulent bacillus phage was also isolated its head was oblong and the tail consisted of a short needle and a plate the one acetobacter phage found resembled coliphage t3 but was of particular interest because of the prominence of the head capsomeres and the three pronged tail
MED	characterization of bacillus subtilis bacteriophages brodetsky anna m university of california los angeles and w r romig characterization of bacillus subtilis bacteriophages j bacteriol 90 1655 1663 1965   a group of six phages sp5 sp6 sp7 sp8 sp9 and sp13 which use the marburg strain of bacillus subtilis as host was characterized these phages referred to as group 1 were examined for the following properties host range plaque morphology stability adsorption kinetics one step growth characteristics calcium requirements serum neutralization thermal inactivation and inactivation by ultraviolet irradiation five unrelated b subtilis phages sp3 sp10 pbs1 sp alpha and sp beta were included in the studies when first isolated none of the group 1 phages was able to replicate efficiently on b subtilis sb19 a mutant of the transforming b subtilis 168 host range mutants capable of growth in sb19 were isolated for all of the group 1 phages except sp13 and are designated the star phages sp5 through sp9 for characterization sb19 was used as host for the star phages and another b subtilis mutant 168b was host for sp13
MED	transduction in bacillus subtilis i comparative examinations have shown that the temperate subtilis phages can be divided into two groups b subtilis strain nrs 231 was an adequate common host sensitive to all the examined temperate phages owing to certain technical advantages this strain was found suitable for the titration subtilis phages ii some cultural differences have been revealed among substrains of b subtilis 168 ind auxotrophs maintained in various laboratories cells in one of these cultures were partly capable and partly incapable of using ammonia ammonia assimilation was transducible to ammonia negative bacteria iii after mitomycin c or ultraviolet ray induction the examined b subtilis strains liberated bacteriocin  like principles this finding is probably analogous to that of seaman et al concerning pbsx defective phages on the basis of bacteriocin production the examined strains were divided into two groups iv several temperate phages isolated in our laboratory were presumably identical with phage pbs 1 phage sp 10 differed from these agents both in antigenic structure and in host range v transduction by some lysates of pbs 1 type phages was observed at frequencies of the order of 10 considerably more and less effective phage materials were yielded by some lysogenic transductants thus transducing phages active in the order of 10 were prepared vi transduction frequency in addition to the properties of the phage was influenced by the physiological condition of bacteria vii transduction of indole and histidine loci was studied by use of his derivatives of strain 168 ind
MED	the carrier state of bacillus subtilis infected with the transducing bacteriophage sp10 bacteriophage sp10 may infect bacillus subtilis to form a carrier system the infected bacteria give rise to infected organisms after six or more successive single colony isolations about 60 of the spores derived from such an infected culture yield clones that produce phage and such spores retain their ability to produce phage even after treatment with antiserum and heating at 80 four hours incubation of carrier spores in nutrient broth yields cultures having more than 10 infective centers per bacterium cultivation of infected organisms in medium containing sp10 antiserum leads to loss of phage and loss of immunity to phage infection dna with a density characteristic of viral dna can be detected in infected bacteria extracts of infected bacteria contain a phage induced deoxyribonuclease activity which attacks both phage and bacterial dna in vitro the phage bacterial complex is therefore best described as a carrier state the dna of the phage and of b subtilis are chemically different enzymatically prepared complementary virus rna has no homology with bacterial dna the lack of homology of this transducing phage dna with the dna of its host and the failure to form a truly lysogenic relationship reinforce previous conclusions that transducing bacterial dna is incorporated into the sp10 virus particle without any recombination between viral and bacterial dna
MED	infectivity of dna isolated from bacillus subtilis bacteriophage sp82 sp82 a newly isolated bacteriophage of bacillus subtilis is described sp82 is closely related to sp8 but differs from sp8 in the density of its denatured dna and in its plating effciency on b subtilis strain sb 1 dna isolated from this phage can be recovered in molecular weight equivalent to the amount contained in a single phage approximately 130 x 10 daltons dna of this molecular weight but not half pieces is infective in competent b subtilis the response of plaque forming ability to dna concentration suggests that four whole molecules are required to initiate an infective center recombination studies with mixed dnas of two non allelic temperature sensitive mutants confirm the existence of an obligatory co operative infective process a second infective procedure that utilizes extracted phage dna is described in this system low concentrations of wild type dna are exposed to the cells at these concentrations the multiple event nature of phage dna infection precludes the formation of unaided plaques however by subsequently superinfecting the dna infected cells with a temperature sensitive mutant and plating under selective conditions genetic rescue of the infecting dna is accomplished and detected infective centers elicited by this marker rescue phenomenon are directly proportional to dna concentration the time of attainment of dnase resistance by phage dna infective centers that have irreversibly adsorbed dna can be measured phage dna infective centers require at least 13 minutes to become totally dnase resistant the reasons for the failure of single phage dna molecules to carry out an infection are discussed in terms of a specific breakage reunion
MED	psychology of childrens dental treatment the communication deals with influences involved in the development of the childs attitude to dental treatment they are extrinsic educational etc and intrinsic constitutional and hereditary their understanding helps to determine the correct psychological policy for the management of the child in the surgery the aim of psychology applied in dentistry is to discover a mode of treatment procedure which would ensure that the child will not be subject to any psychic traumatization psychophylaxis its second aim is the management of the so called difficult child and his treatment to understand better the childs frame of mind during dental treatment the situation in the surgery is dealt with step by step as the child experiences it through his senses and his psyche beside the basic senses  dash hearing and seeing  dash others are also affected touch pressure sensation smell and taste children during dental treatment are nearly always in a state of raised emotional tension and are susceptible to anxiety reactions according to the degree of fear which they manifest children may be classed into categories of cooperating and difficult patients the psychological procedure for the treatment of children of both groups is based on the principles summarized in the section psychophylaxis in dentistry in difficult children it is often necessary to employ yet other psychological measures psychotherapy suggestion etc in extremely exacting cases premedication helps sometimes to find contact with the child the experimental part of the work demonstrates the following findings 1 dental treatment consists of a series of interdependent traumatizing impulses many of them appear only after a close analysis of the situation 2 the adverse response similar to that elicited by pain may be due also to sensory impressions with a negative emotional background 3 psychic traumatization of the child during dental treatment can be prevented by relatively simple psychological measures
MED	relation of emotional changes during pregnancy to obstetric complications in unmarried primigravidas this study was designed to assess the psychological changes experienced by white unmarried primigravidas during pregnancy the relationship between manifest anxiety and clinical factors such as labor time and mean birth weight and the personality differences between normal and abnormal obstetric cases the kent egy intelligence scale the taylor manifest anxiety scale and the mmpi were administered to 160 obstetric patients at the beginning of the third trimester of pregnancy with the mmpi and taylor being readministered post partum reliable group personality changes observed from pre  to postdelivery supported the contention that pregnancy is a time of emotional upset following delivery each patient was classified as normal or abnormal dependent on the clinical course of parturition delivery and condition of the offspring there were no significant differences between these groups with respect to age or intelligence reliable differences were found however for manifest anxiety and total labor times in addition a positive relationship was found between manifest anxiety and birth weights personality differences found at predelivery between the subgroups were largely attributable to the abnormal groups greater neuroticism anxiety and use of the ruminative ego defenses post partum the personality characteristics of the subgroups were quite similar both groups showed greater personality stability following delivery with the most striking changes from predelivery demonstrable in the abnormal group the magnitude of these changes were interpreted as emotional lability and related to obstetric complications by activation of various physiological regulator systems
MED	stranger and separation anxiety in infancy anxiety responses to strangers and to separations from mother were studied longitudinally in 19 infants between the ages of three and 23 months by direct observations and by interviews with the mother benjamins hypotheses concerning the differentiation and immediate dynamics of infantile stranger and separation anxiety were supported by the findings differences in onset period of highest intensity termination and ratios in individuals were found between the two anxieties tests of the relationship between the two anxieties were supportive of deductive predictions made by benjamin sex differences in intensity of the two anxieties were found
MED	mental retardation related to hypercalcaemia for more than 20 years a number of retarded children and adolescents have been observed who show points of striking similarity we recognise in them a well defined type that is clearly distinguishable from other forms of mental deficiency they are therefore described in detail some of the children have had infantile hypercalcaemia but it is assumed that other aetiological factors are also involved there is a characteristic facies and usually congenital heart disease ordination is poor there is a constant failure to thrive in infancy with episodes of vomiting often with constipation mentally the children also show great similarities their iq is about 40 50 but they show outstanding loquacity and a great ability to establish interper  sonal contacts this stands against a background of insecurity and anxiety
MED	psychological effects of circumcision in order to evaluate the psychological effects of circumcision a small study was arranged in which twelve children from average and low socio economic level were given goodenough dam test cat rorschach and two sets of stories prior to the operation and following it the results of the tests showed that circumcision performed around the phallic stage is perceived by the child as an act of aggression and castration it has detrimental effects on the childs functioning and adaptation particularly on his ego strength by weakening the controlling and defensive mechanisms of the ego and initiating regression it loosens the previously hidden fears anxieties and instinctual impulses and renders a feeling of reality to them what is expressed following the operation is primitive archaic and unsocialized in character as a defensive control and protection against the surge of the instinctual forces coming from within and the threats coming from outside the ego of the child seeks safety in total withdrawal thus isolates and insulates itself from disturbing stimuli the results of the study raised some questions concerning certain psychoanalytic formulations for which further research was suggested possibilities for future research were also discussed
MED	changes in childrens behavior after hospitalization some dimensions of response and their correlates changes in 387 childrens behavior following hospitalization were evaluated by means of a questionnaire sent to parents a week after discharge factor analyses revealed that childrens responses to hospitalization and illness were of six types i general anxiety and regression ii separation anxiety iii anxiety about sleep iv eating disturbance v aggression toward authority and vi apathy withdrawal scores for these six factors types of responses as well as a total score were analyzed by univariate and in most cases multivariate analyses of variance four variables  dash sex prior hospitalization degree of pain experienced during hospitalization and birth order  dash were essentially unrelated to any type of response by any analysis age duration of hospitalization and occupational status were each significantly related to one or more types of responses comparison of the mean factor and total scores for the full sample with the levels indicative of no overall change indicated that the combination of illness and hospitalization is a psychologically upsetting experience for children in general resulting in increased separation anxiety increased sleep anxiety and increased aggression toward authority
MED	isozymes of lactic dehydrogenase sequential alterations during development applications of isozymes in various biological contexts have been reviewed diagnosis of several disease states has been facilitated by examination of the serum isozyme pattern which has been shown to correlate in some conditions with the isozyme pattern of pathologically involved tissues physico chemical studies of human ldh isozymes have revealed differences among isozymes in affinity for a given substrate comparative studies of ldh isozymes within the erythrocyte from various vertebrate species demonstrated a marked species variation in the number of ldh isozymes in the distribution of total ldh activity among them and in their electrophoretic mobilities during development of chick rabbit and human tissues characteristic sequential alterations in the ldh isozyme pattern occurred and consisted for liver and muscle in loss of the most rapidly migrating anodal bands and increased activity in the cathodal bands and slower migrating anodal bands in heart the reverse changes were observed if high enough ldh activities of early fetal tissue extracts were applied to the gel the full complement of ldh isozymes was observed however in lower concentrations the cathodal bands which in the starch gel disappear more rapidly on dilution than do the anodal bands were not observed a species specific isozyme pattern is obtained in long term culture of rabbit chick and human cells independently of the tissue of origin there occurs in cells in culture a sequential series of isozyme alterations characterized by decreased intensity of rapidly migrating anodal bands the shift toward prominence of cathodal isozymes during both fetal development and tissue culture can be explained by postulating the increased activity of the gene producing one of the subunits of ldh with a concomitant decrease in the activity of the gene producing the second subunit practical applications of the study of isozymes in tissue culture were discussed
MED	establishment of a cell line in vitro from a case of human lung cancer 1 one cell line has been established from the pneumonectomized specimen of a case with lung cancer which was diagnosed as undifferentiated cell carcinoma and partially adenocarcinoma by its histological findings and was characterized with intracytoplasmic fat droplets in them 2 the morphological changes of the cells were repeated but they have been stabilized to their epithelial shapes after the 35th transfer the cell atypy of the culture was remarkable phagocytosis of the cell line has not been observed it was characterized that the intracytoplasmic droplets found in the original cancer cells have been maintained in the cultured cells even in their mitotic stage throughout the cultural course 3 concerning the chromosomal constitution diploid cells were only 15 per cent the range of chromosome number did not show sharp peak forming two groups of near diploid and near tetraploid ranges 4 transplanting the cell to cheekpouches of golden hamsters the implanted cells grew from the inoculum of 10 cells in conditioned animal but did not show the invasiveness to neighbour tissue and metastasis to other organs
MED	factors influencing development of tumors in frogs 1 study of 75 spontaneous tumors of vermont frogs showed three pathological grades of malignancy present aggressive renal adenocarcinoma in some 30 per cent medium adenocarcinoma in 50 per cent and lower grade mixed with tumors of undetermined origin in the remaining 20 per cent 2 correlation with parasite infections trematodes was demonstrable in only few cases in the kidney hyperplasias and neoplasias grading into lung primary carcinoma have been found in the lung in r pipiens temperatures below 15 c protected animals from lung as well as kidney disease higher temperatures disturbed the host parasite relationships and led to higher incidence of malignancy in the bullfrog precancer was clearly associated with the worm attachment discs 3 other histological types of tumors in vermont frogs included lymphosarcomas liposarcoma mesothelioma epithelioma and adrenal and cartilage tumors of uncertain malignancy 4 improved methods of obtaining tumor filtrates allowed greater probability of inducing malignancy with direct renal injection in 106 frogs 37 per cent developed histologically provable cancers in the ranges of three to seven months twenty six per cent showed some pre cancer response and 43 per cent were negative within the series receiving filtrate from high malignancy donors one group yielded 100 per cent positive the others 50 and 38 per cent respectively 5 among animals injected with low malignancy filtrate fewer tumors resulted some of these were clearly vesicular carcinomas and could be classed as lung tumors 6 improved tissue culture methods allowed explants to live in liquid media under perforated cellophane up to one year slower growth aided by lower temperatures 16 c improved the microecology of cell types and allowed detailed daily observations of each cells intranuclear and intranucleolar physiology for extended time lapse cine photography 7 mechanisms for malignant transformation are related to increased activity and production of nucleolar dna and rna the infective dna hypothesis is not classical virus theory but it does offer detailed support
MED	mitotic lymphocytes in primary tissue cultures of normal and neoplastic human lung normal and tumor tissue explants from 33 resected human lungs were studied in vitro lymphocyte mitoses were observed in tissue cultures derived from 12 of the lungs the ability of lymphocytes to undergo mitotic division in human lung tissue culture has not been reported previously in the autologous systems used lymphocyte mitoses were much more common in cellular outgrowths derived from non neoplastic tissue than they were in the outgrowths derived from cancer bearing explants no differences were observed in the total number of nondividing lymphocytes present in the non neoplastic and neoplastic preparations the in ritro systems employed are promising tools for further contributions to an already well established clinicopathologic relationship between lymphocytes and cancer cells phase contrast and time lapse cinephotomicrographic records were obtained of the mitotic process and special attention was paid to the structural details certain findings were of particular interest namely the formation of a dense chromatin ring during telophase the variable occurrence of cytoplasmic bubbling and the death of lymphocytes during early metaphase exploding metaphase an elaboration and discussion of these findings have been presented
MED	studies on transformation of syrian hamster cells by simian virus 40 sv40 acquisition of oncogenicity by virus exposed cells apparently unassociated with the viral genome lines of syrian hamster lung and liver cells originally exposed as primary cultures to large doses of sv40 exhibited increased growth rate high plating efficiency morphological transformation and in some instances oncogenic potential after unusually long intervals in at least two lines acquisition of oncogenic potential occurred independently of morphological transformation in none of a total of 11 cell lines studied in detail was conclusive evidence for the presence of the sv40 genome obtained
MED	eye and kidney tissue reactions to heterologous anti uveal antibodies the uvea lens capsule and kidney glomerulus in the albino wistar rat have a common antigenic component s the uvea and lens capsule in the pigmented bovine eye also have a common antigenic component s these results were demonstrated by the immunofluorescence technique the common antigenic sites in the uvea were assumed to be the basement membrane surrounding the vascular trees in the tissues the possibility of the basement membrane participation as an antigenic source for inducing sympathetic ophthalmia is discussed
MED	experiments dealing with the role played by the aqueous humor and retina in lens regeneration of adult newts 1 these three groups of experiments involve approximately 140 eyes of adult newts triturus v viridescens they were devised to examine what if any role the aqueous humor plays during lens regeneration from the dorsal iris 2 many daily injections of aqueous humor from normal eyes were made in lentectomized eyes for as long as 96 days in some cases as controls some lensless eyes were daily injected with holtfreters solution in others aqueous humor was merely withdrawn 3 procedures for the injection experiments are difficult to control however the most successful cases showed varying degrees of inhibition and retardation of lens regeneration 4 pairs of eyes were united at large adjacent wound openings to provide a common reservoir of aqueous humor bathing both lenses and dorsal irises in some cases the eyes were placed on the side of the body in others more successful unions were made by fusing a transplanted eye to the right eye of a host 5 approximately three months after operation one of two large lens regenerates in a pair of perfectly fused eyes was removed six weeks later a new large lens regenerate reappeared in most of the lentectomized units in the presence of the intact lens of the other unit 6 there is a strong possibility that the more than normal amount of neural retina present provided a more powerful retinal factor for lens regeneration than the inhibiting influence of the intact lens in the environment
MED	correlation between the mast cells and histamine content of the eye in cattle the authors have examined the mast cell content of the eyes of cattle and have established that most of the mast cells are contained in the conjunctiva the optic nerve and the ocular muscles fewer occur in the sclera and iris and least in the ciliary body and choroid cornea lens and retina do not contain mast cells the histamine content of the ocular tissues and their mast cell contents generally run parallel however the cornea is exceptional in that its histamine does not occur in a bound state but in some form which is readily available to a mild process of extraction tyrode solution at 4 c
MED	studies in sickle cell anemia xxi clinico pathological aspects of neurological manifestations neurologic manifestations are frequent in patients who have sickle cell disease these manifestations may be the earliest presenting signs and symptoms and they are so variable that the patient may be erroneously diagnosed as having conditions such as meningitis poliomyelitis subdural hematoma neoplasm subarachnoid hemorrhage lead encephalitis subacute bacterial endocarditis and congenital malformations of the brain furthermore development of these manifestations cannot be predicted on the basis of the type of crisis involved prognosis following neurological involvement is unpredictable but recurrent episodes together with abnormal electroencephalographic readings suggest a poor outcome such patients die or are the victims of rather severe neurological deficits neurological examination of these patients suggests diffuse involvement of the cerebral hemispheres examination of the pathological material however often fails to reveal thromboses the striking findings are infarcts in the white matter and perivascular hemorrhages the thesis that the abnormal neurological findings in these patients are actually due to sickle cell disease is supported by the fact that all such symptoms appear in association with clinical circumstances known to induce sickling these include surgery and anesthesia fever and infection
MED	attenuation curves of the human eye under normal and pathological conditions a method is described which allows the determination of attenuation curves of the human eye those curves are obtained by plotting the critical depth of modulation cmd as a function of the critical fusion frequency cff routine experiments were carried out for a 2 test field showing a sinusoidal periodical variation of its luminance surrounded by an extensive area with a luminance equal to the average luminance of the test field attenuation curves were obtained for normal observers under different experimental conditions and for a number of patients it is shown that this method affords us information which cannot be obtained by means of the classical methods for measuring the cff
MED	central nervous system manifestations of periarteritis nodosa in the 114 cases of pathologically proved periarteritis nodosa reviewed 53 patients 46 percent had symptoms and signs of central nervous system or cranial nerve involvement thirty nine patients had both cerebral manifestations and neuropathy 38 had neuropathy alone and 14 had only cerebral symptoms and signs the most common cerebral manifestation was that of mental derangement usually an organic psychosis or confusional state headache convulsions blurred vision vertigo and sudden unilateral visual loss were the most common symptoms referable to the central nervous system the most common abnormalities on examination were retinopathy hemiparesis and signs of a brainstem lesion there was no difference in duration of life after onset of disease in those with and those without central nervous system involvement
MED	see saw nystagmus an unusual sign of lesions near the third ventricle a case of see saw nystagmus in a child with craniopharyngioma and bitemporal hemianopsia is described and reference is made to previous case reports the basis for this curious sign is not clear but the site of the lesion must be considered to be in the region of the third ventricle since bitemporal hemianopsia is a necessary part of the syndrome the sign is not common but when present points to a lesion near the third ventricle
MED	implications of gerstmanns syndrome of 465 consecutive patients subjected to a standardized battery of neuropsychological tests 111 had one or more components of gerstmanns syndrome each of these 111 patients had some evidence of organic brain dysfunction in addition to gerstmann components as the number of gerstmann components increased the responsible brain lesions tended to be larger more highly destructive of tissue and to cause greater neurological impairment every patient with four gerstmann components had associated evidence of severe impairment of brain functions and the lesion or underlying disease was likely to compromise survival of the patient the syndrome is not to be regarded as an autonomous entity but merges with numerous other neurological deficits notably dysphasia in agreement with benton we find no justification for singling out the four gerstmann components as a separate syndrome unless one is also prepared to recognize that any other arbitrary groups of concurrent deficits are also separate syndromes in at least three of 23 patients with all four gerstmann components the angular gyrus as shown by necropsy examination was not involved by the lesion however the probability that the left hemisphere contained a lesion increased with the number of gerstmann components and the probability of involvement of the left posterior parasylvian area also increased with the increase in the number of gerstmann components with two three or four gerstmann components the lesions were never restricted to the angular gyrus but tended to spread widely over the parietal temporal and occipital lobes as to localizing significance gerstmanns syndrome has approximately the same degree of cogency as dysphasia
MED	alterations of visual evoked response in the presence of homonymous visual defects the visual evoked response ver was studied by means of computer averaging in 32 normal subjects nineteen patients without visual disorder but with unilateral cerebral lesions and 30 patients with homonymous visual field defects an early negative positive negative complex was recorded between laterally placed occipital electrodes and a vertex reference latencies were prolonged in the hemianopic patients some amplitude asymmetries were noted in the brain damaged controls but were more pronounced in patients with visual defects the recordings in the hemianopic patients were differentiated from those in both control groups by the presence of aberrant wave forms 2 cases prolonged latencies 3 cases and amplitude depression of greater then 50 per cent of the positive wave on the abnormal side 16 cases pathologic verification was obtained in three patients and demonstrated a correspondence between alterations in the ver and the presence of lesions of the geniculocalcarine system
MED	cerebro vascular lesions and livedo reticularis extensive livedo reticularis has been observed in one man and five women who have suffered from a series of cerebrovascular lesions the neurological disabilities have included aphasia homonymous hemianopia and hemiplegia but have been remarkable for the degree of recovery which has occurred it is presumed that the livedo which has been found in only one patient without neurological lesions is related to the cerebrovascular incidents investigations have failed to show any evidence of polyarteritis nodosa disseminated lupus erythematosus and thrombocythaemia and an arteritis of unrecognized type is suggested as the etiology
MED	seesaw nystagmus case report elucidating the mechanism the eighth recorded case of see saw nystagmus is reported features in this case are analyzed and evidence to suggest that this form of nystagmus is ocular rather than central in origin is offered see saw nystagmus unlike true vertical nystagmus is not of itself indicative of a brain stem lesion
MED	supratentorial paratransversal meningiomas the author describes 6 cases of supratentorial paratransversal meningioma clinically the development of these tumours is slow and the chief neurological signs are homonymous hemianopia contralateral hemiparesis and speech disorders when the tumour is on the dominant side radiologically carotid angiography permits identification of these tumours easily surgically the tumours were removed completely and although in 2 cases the transverse sinus had to be resected this caused no damage one patient who was operated on twice and whose histological specimen on the second occasion showed that the meningioma was malignant died seven months after the second operation the other patients are well and free of neurological deficits from 1 to 12 years after operation
MED	life span and lymphoma incidence of mice injected at birth with spleen cells across a weak histocompatibility locus newborn cogenic c h mice receiving injections across a weak h i h i histocompatibility barrier exhibited life shortening and a high incidence of lymphomatous disease during mid adult life in control experiments h i h i lymphomatous disease developed much later life both mouse strains when not given injections as new borns manifest only a negligible incidence of lymphoma or leukemia these findings are variably interpretable in terms of oncogenic virology and of the immunologic theories of aging and cancer by analogy with transplantation disease mechanisms
MED	the heterogeneity of rheumatoid factors and the genetic control of polypeptide chains of globulin 1 evidence is presented that most rf proteins are heterogeneous in their antigenic composition although occasional ones are homogeneous and thus resemble the paraproteins 2 studies pointing out some of the difficulties encountered with currently available preparations of polypeptide chains in the genetic mapping of globulin are described
MED	progynon a depot preparation with oestrogenic action in the treatment of prostatic carcinoma a derivative of a natural oestrogen  dash oestradiol undecylate progynon depot  dash was given in depot form by injection to a group of patients with prostatic carcinoma the study showed progynon depot to reduce the excretion of androgen metabolites in the urine the results suggest that the preparation reduced the testicular production of androgens but probably not that of the adrenal glands the depot effect and clinical action of the preparation are described briefly
MED	urinary 17 ketosteroid excretion study in radiation induced menopause in carcinoma breast 1 urinary 17 ketosteroid estimation results are given in 11 patients subjected to radiotherapeutic sterilisation 2 a high dosage level was used in all these cases 3 results indicate some suppression of ovarian function within 2 weeks of sterilisation
MED	prostatic cancer of a young person with primary hypogonadism the prostatic carcinoma of a 34 years old man with primary hypogonadism was presented endocrine environment of relative estrogenic excess is suspected to have played the leading part in pathogenesis of this case
MED	urinary excretion of neutral 17 ketosteroids and pregnanediol by patients with prostatic cancer and benign prostatic hypertrophy urinary neutral 17 ketosteroid fractions and pregnanediol excreted by 21 patients with prostatic cancer 17 patients with benign hypertrophy and 59 clinically well subjects were assayed to determine whether differences exist patients with prostatic cancer and those with benign hypertrophy excreted significantly less androsterone than the clinically well subjects a disproportionately lower level of androsterone than etiocholanolone resulted in a significantly lower androsterone etiocholanolone ratio in both groups the specificity of the findings is discussed the lower levels of androsterone excreted by patients with benign hypertrophy were associated with an extended period of hospitalization patients hospitalized less than 5 days excreted androsterone at levels not significantly different from the clinically well subjects lower levels of androsterone excreted by patients with prostatic cancer were not explained by the presence of metastasis the duration of hospitalization loss of appetite or other definable differences when each was considered singly the possible interrelationships of clinical differences prevent assigning lower excretion levels to the cancer state alone
MED	i urinary excretion of neutral 17 ketosteroids and pregnanediol by patients with breast cancer and benign breast disease urinary levels of neutral 17 ketosteroid fractions and pregnanediol excreted by 114 women 56 premenopausal and 58 postmenopausal were determined subjects studied were included in 4 premenopausal groups breast cancer 6 benign breast disease 18 sick control 8 well control 24 and 3 postmenopausal groups breast cancer 21 sick control 17 well control 20 levels of androsterone and etiocholanolone excreted by premenopausal patients with breast cancer were significantly less than levels excreted by other premenopausal groups and they did not differ significantly from levels excreted by postmenopausal patients with breast cancer disproportionately lower levels of the 11 desoxy 17 ketosteroids than 11 oxy 17 ketosteroids excreted by premenopausal patients with cancer resulted in significantly lower ratios than those found in other premenopausal groups ratios associated with premenopausal patients with cancer did not differ significantly from those of postmenopausal patients with cancer lower levels of androsterone and etiocholanolone were not explained by debilitation
MED	the morphologic demonstration of an alveolar lining layer and its relationship to pulmonary surfactant the presence of an alveolar lining layer was histologically demonstrated in animal lungs by ultraviolet microscopy this layer appeared as a thin fluorescent line at the air tissue interface the fluorescent lining layer could be abolished from lung sections by extraction with chloroform methanol and was diminished by digestion with cl welchii a toxin lecithinase suggesting that the structure was a lecithin containing lipid an alveolar lining structure was also identified by the use of phosphatide and polysaccharide stains suggesting that the lipid was a phosphatide but that a mucopolysaccharide component might also be present bilateral cervical vagotomy resulted in diminution or loss of the fluorescent alveolar lines and abnormal surface tension properties of lung extracts this suggested that the presence of the fluorescent material was associated with the surface activity of the lung alveolar lining structure could not be demonstrated by electron microscopy even with special staining techniques
MED	experimental emphysema basis review and critique normal lung structure has been described as a rich capillary bed in a finely partitioned airspace with unique surface active effects morphologic criteria of the lesions of human pulmonary emphysema include evidence of destruction residual vascular remnants the absence of significant amounts of fibrosis and altered conducting airways without anatomic obstruction experimental studies relating to the pathogenesis of emphysema have been reviewed and critically evaluated stress has been placed on the necessity to control the biologic factors influencing the action of any specific etiologic agent
MED	alveolar lining cells and pulmonary reticuloendothelial system of the rabbit complete freunds adjuvant was injected intravenously into rabbits and the cellular response in the lungs was investigated the population of cells within the alveolar spaces was contributed to by monocytes of the circulation mesenchymal cells of the alveolar walls and epithelial lining cells of the alveoli the abnormal epithelial lining during the proliferative phase was the result of an increase in size and number of the cells that line the normal alveoli as healing progressed a structurally normal alveolar lining was found
MED	time course of changes in surface tension and morphology of alveolar epithelial cells in co2 induced hyaline membrane disease atelectasis and hyaline membranes produced by exposure of guinea pigs to 15 percent co2 were found to be associated with disappearance of lamellar bodies in the large alveolar lining cells granular pneumocytes and an associated decrease in surfactant as indicated in the rise of minimal surface tension of the lungs this process is limited to the uncompensated phase of respiratory acidosis and is reversed during the compensatory phase the parallel time course in changes of surface tension and alterations of lamellar bodies in the granular pneumocytes provides additional evidence for the identification of the latter as the cells responsible for the secretion of surfactant
MED	cortisone and atypical pulmonary epithelial hyperplasia further studies including electron microscopy tissue culture animal transplantation and long term observations previous work in rabbits showed that there was a proliferation of cells within pulmonary alveoli following intratracheal injection of nitric acid and that the proliferation was greatly enhanced by the administration of cortisone to the animals electron microscopic observations indicated that these were morphologically large alveolar lining cells tissue culture studies of damaged and normal lung with and without cortisone showed no evidence for a direct effect of the drug on the proliferation of these cells this observation together with the knowledge that fibrosis was delayed in the cortisone treated animals support the thesis that the cortisone effect is an indirect one transplantation of damaged lung tissue to hamster cheek pouch failed to reveal evidence of growth within the period of observation 99 to 420 days there was evidence that the proliferation subsided considerably and no neoplasms developed
MED	some observations on myelin glial relationships and on the etiology of the cerebrospinal fluid exchange lesion the present paper presents cytological observations from developing kitten spinal cord and from spinal cord white matter reacting to injury it also presents some recent experiments on the mechanism of etiology of the csf exchange lesion drawing on these various sources the authors propose specific functions for some of the cell types present in spinal cord white matter
MED	lactate and pyruvate in the brain of rats during hyperventilation experiments on anesthetized and curarized rats under artificial ventilation show that during hyperventilation lactate and pyruvate are markedly increased both in blood and in brain the lactate pyruvate ratio which remains in blood the same as in control conditions is systematically decreased in brain during hypoxia ventilation with 7 oxygen in nitrogen lactate rises markedly in blood and in brain the lactate pyruvate ratio which is strongly increased in blood shows a small rise in brain these observations could indicate that a different mechanism is responsible for the rise of lactate in brain during hypoxia and hyperventilation the important augmentation of lactate in brain during hyperventilation can give an explanation for the delayed rise which is seen in the lactate level in cerebrospinal fluid in these conditions
MED	cisternal fluid oxygen tension in man using a beckman micro oxygen electrode we have studied the oxygen tension simultaneously in the cisterna magna the internal jugular vein and in arterial blood under various conditions the results suggest that the cisternal oxygen tension to some degree reflects the average oxygen tension of the surrounding brain tissue and besides reflecting the available free oxygen to the brain it registrates changes of short duration in the cerebral blood flow
MED	ventricular septal defect with prolapsed aortic valve and outflow tract obstruction a case of ventricular septal defect combined with aortic valvular lesion and infundibular pulmonic stenosis is described the right coronary cusp of the aortic valve protruding through the ventricular septal defect was demonstrated by right ventricular angiocardiography as a polyp like mass in the right ventricular outflow tract cardiac catheterization and angiocardiography showed progressive right ventricular outflow obstruction
MED	functional adaptations of the right ventricular outflow tract in congenital heart disease functional adaptations in the right ventricular outflow tract have been discussed in relation to the development of acquired pulmonary stenosis it is concluded that physical forces as well as structural abnormalities may greatly influence both the clinical picture and the life history of many patients with congenital heart lesions the importance of further serial haemodynamic studies to provide a fuller understanding of the natural course of many lesions is stressed so that better advice about prognosis and the optimal time for surgical treatment may be given
MED	mitral atresia associated with pulmonary venous anomalies pulmonary venous anomalies were observed in 5 among 29 specimens with mitral atresia in 4 of these 5 the anomalous pulmonary veins took the form of anomalous pulmonary venous connexion in the remaining case the pulmonary venous anomaly was represented by cor triatriatum in 3 group i mitral atresia and premature closure of the foramen ovale coexisted the anomalous pulmonary venous connexions in this group provided collateral routes for the flow of pulmonary venous blood and can be understood as developing en response to obstruction at the foramen ovale when the mitral valve is atretic in the remaining 2 group ii no such causative factor could be invoked in one of the latter group total anomalous pulmonary venous connexion coexisted with a common atrium in the other cor triatriatum coexisted with a patent foramen ovale pulmonary venous obstruction occurred in each of the 5 cases
MED	basal metabolic rate after cardiovascular surgery the basal metabolic rate and respiratory equivalent of patients were determined during 8 days of convalescence from cardiovascular surgical operations performed with or without cardiopulmonary bypass the results were compared in patients who had undergone operation for different diseases metabolic rate in the majority of cases was increased but was commensurate with body temperature some patients particularly those requiring open operation on the aortic valve had raised metabolic rates which could not be explained solely by pyrexia all types of patients in this series had elevated respiratory equivalents which persisted throughout convalescence these equivalents were greater in patients treated with cardiopulmonary bypass than in patients treated without bypass
MED	surgical treatment of ventricular septal defect the surgical technique of closure of ventricular septal defects in 80 cases 37 cases of isolated defects and 43 cases of tetralogy of fallot is discussed in the light of the follow up results the use of a patch for closure has reduced the incidence of recurrence to 4 percent com  pared with 18 percent when direct suture was performed the incidence of heart block also decreased from 15 percent when direct suture was used to 4 percent with a patch the transatrial approach is preferred for isolated ventricular septal defects the ventricular approach is preferred for cases with tetralogy of fallot in cases combined with aortic insufficiency only small defects are closed through the aorta larger defects are closed in the usual way at a first stage operation and a total valve prosthesis is introduced at a second operation there was an operative mortality of 6 percent in isolated ventricular septal defects compared with 27 percent in cyanotic patients with tetralogy of fallot
MED	some hemodynamic observations in congenital heart disease with special reference to pressure curves in ductus arteriosus hemodynamic observations in 100 congenital heart disease cases are made based on data in the department of pediatrics kyoto university between may 1961 and december 1963 we have classified these 100 cases according to the malformation from the hemodynamic view point our cases were classified into the following groups 1 ventricular septal defect 35 cases small ventricular septal defect 20 moderate ventricular septal defect 9 marked ventricular septal defect 4 ventricular septal defect with pulmonary stenosis 2 2 patent ductus arteriosus 21 3 atrial septal defect 19 atrial septal defect 14 atrial septal defect with pulmonary stenosis 5 4 pulmonary stenosis 5 5 tetralogy of fallot 14 6 aortic stenosis 3 7 aortic insufficiency 3 aortic insufficiency with ventricular septal defect 2 aortic insufficiency with pulmonary stenosis 1 in sonre small ventricular septal defect we tried the vasoactive drugs phenylephrine was injected slowly into the right ventricle via the catheter a rapid rise in femoral arterial pressure associated with bradycardia and intensiffication of the systolic murmur was observed after the administration of amyl nitrite a rapid fall in femoral arterial pressure associated with tachycardia and softening of the sys  tolic murmur was observed in patent ductus arteriosus when the cardiac catheter is withdrawn slowly from the aorta into the pulmonary artery the outstanding pressure curve is recorded in ductus arteriosus the systolic pressure curve in the ductus arteriosus is the same as the systolic pressure in the aorta and the diastolic pressure curve in the ductus arteriosus has a diastolic dip followed by a late diastolic pressure peak in patent ductus arteriosus when the cardiac catheter is withdrawn from the left pulmonary artery to the right ventricle the pressure curve reveals a considerable characteristic rise in pulmonary arterial pressure which is regarded as an effect of the transmission of systemic pressure through the ductus arteriosus
MED	a study on the direction of inscription of the vectorcardiographic t loop in left and right ventricular hypertrophy 1 frank lead vectorcardiogram was recorded in 30 normal persons and in 323 cases with hypertension and acquired and congenital heart disease the t loop was classified into 8 types according to the directions of inscription in 3 planar projections frequently observed types were examined with the direction of the maximal t vector 2 in majority of normal cases the t loop was inscribed counterclockwise in horizontal and clockwise in sagittal planes 3 in left ventricular hypertrophy abnormal inscription of the t loop was observed with abnormal rightward and superior deviation of its maximal vector and the t loop oriented more than 120 in horizontal plane was usually accompanied by abnormal inscription percentage of abnormal inscription was higher in cases with cardiac complaints 4 in right ventricular hypertrophy directional change of the t loop was relatively small but changes in inscription of it were common the t loop was always inscribed abnormally in cases with abnormal inscription of the qrs loop 5 the concept of the polar vector was found to be valuable in studying the inscription and the direction of the t loop significance of changes in inscription of the t loop was discussed
MED	pulmonary vascular plexiform lesion pathogenetic studies an attempt was made to test the theory that in pulmonary arterial hypertension the plexiform lesion is a jet lesion beyond points of arterial stenosis resulting from nonspecific intimal thickening in 39 subjects with such congenital communications as are associated with pulmonary arterial hypertension the lungs were studied histologically in each there was an additional element of pulmonary venous obstruction it is likely that in the absence of pulmonary venous obstruction adult patients with only the congenital communication would have developed plexiform lesions in the three adult patients in the study no plexiform lesions were identified among the 36 infants or children one subject showed plexiform lesions a 53 day old girl with mitral atresia ventricular septal defect and patent ductus arteriosus while the findings in the three adult subjects support the theory regarding the genesis of plexiform lesions the findings in the one infant with plexiform lesions appear to contradict it
MED	renal hemosiderosis blue kidney in patients with valvular heart disease anatomic evidence of intravascular hemolysis i e renal hemosiderosis was found at necropsy in 4 of 132 patients who died of severe valvular heart disease the aortic valve in each of these 4 patients was heavily calcified immobile and portions of the calcific deposits were in direct contact with the blood hemolysis in each patient was attributable to direct trauma to erythrocytes traversing the stenotic valve and the frequency of trauma was increased by an associated regurgitant flow renal hemosiderosis was not observed in any patient with isolated mitral valve disease or in those with combined mitral and tricuspid valve malformations
MED	tumor scanning with radioactive cesium fourteen patients with cancer were scanned 10 minutes to 48 hours after injection of radioactive cs and satisfactory scans of the tumors were obtained in seven positive scans were obtained in large superficial tumors in a pulmonary lymphoma and in a carcinoma of the upper third of the esophagus the negative scans were all in abdominal tumors correlations were made with data obtained from external counting and by well scintillation counting of biopsy specimens two modes of uptake are suggested a early uptake due to vascularity and probably not proportional to stable cesium content and b a later uptake based upon greater alkali metal content of tumors than of normal tissue
MED	lung scanning with colloidal risa the use of colloidal risa injected intravenously in a particle size of 10 50 microns followed by lung photoscanning offers a practical atraumatic method of visualizing pulmonary artery occlusions in the dog the fact that the particles have a relatively short biological half life appears to decrease the radiation dose delivered and the duration of occlusion of pulmonary capillaries as compared to ceramic microspheres work is in progress to apply this technique to the study of pulmonary artery occlusion in the human
MED	multivariate comparison of results of treatment in chronic lymphocytic and chronic granulocytic leukemia the results of several clinical trials have been analyzed by multivariate procedures which rely completely on laboratory findings and do not involve scoring specific changes or subjective evaluations statistically significant differences among drugs after three months of therapy were demonstrated a relationship between the multivariate method and the subjective evaluation was demonstrated which indicates that if the subjective evaluation is an estimate of the physiologic state or prognosis of the patient then so are the completely objective techniques used here
MED	oxacillin  apparent hematologic and hepatic toxicity bone marrow depression and hepatocellular dysfunction developed in an allergic woman receiving 3 0 gm of sodium oxacillin by mouth daily for nearly three months discontinuing the drug and administering corticosteroids and antibiotics resulted in apparent recovery the toxic potentialities of oxacillin should be appreciated
MED	drugs and neonatal jaundice this paper is not intended as an exhaustive review of bilirubin metabolism nor of the many factors which may result in exaggerated physiologic jaundice for such a review the interested reader is referred to the excellent articles by zuelzer and brown brief mention has been made of the mechanism by which certain drugs may contribute to the development of hyperbilirubinemia a few drugs the water soluble vitamin k derivatives sulfasoxazole gantrisin the salicylates and novobiocin have been unequivocally shown to affect adversely the newborn infants ability to handle bilirubin in time other compounds will definitely be incriminated it is important to remember that the administration of a drug to a mother just prior to delivery may result in appreciable concentrations of the compound in the infants serum and that drugs administered to the nursing mother may be excreted in breast milk and thereby absorbed by the infant careful consideration of the drugs given not only to the newborn but also to the mother is therefore essential if we are to avoid what may be termed iatrogenic hyperbilirubinemia
MED	amputation in patients over 80 years of age although patients over 80 years of age can be expected to have poor physical reserve and many co existing diseases our observations show that nevertheless they can be subjected to surgical procedures without undue mortality the mortality rate can be maintained at a minimum if the surgeon considers the factors that contribute to its increase in the elderly this necessitates 1 careful evaluation of the patient and treatment of any pre existing or co existing disease 2 proper control of electrolytes 3 avoidance of infection 4 prompt correction of any postoperative hypotension 5 postoperative pulmonary ventilation and tracheal cleansing and 6 avoidance of prolonged surgical procedures a group of 26 patients past the age of 80 years underwent amputation of a lower extremity without undue mortality 9 deaths lumbar sympathectomy is not considered advisable in these aged pa  tients the standard mid thigh operation can be questioned in the younger patient but it is the procedure of choice for removal of a gangrenous extremity in patients over 80 years of age
MED	radical operation for ventricular septal defect in infancy ventricular septal defect is the most common congenital anomaly of the heart in infancy and has a poor prognosis we have operated upon 18 infants all under one year of age for ventricular septal defect there has been successful repair in 16 cases at present hypothermia with a surface cooling method has proved to be superior to the artificial heart lung machine because of the simplicity and the good operative results with its use in addition early operation during the infantile period will cause less psychological impact on infants these advantages are sufficient for us to advocate radical operation of ventricular septal defect in infancy even including the severely ill children
MED	specific suppression of tumor growth by isolated peritoneal macrophages from immunized mice methods were presented by which macrophages may be isolated from the peritoneal cell population of mice these cells and for comparison peritoneal lymphocytes and lymph node cells were tested for immunologic activity by injecting a mixture of the test cells and tumor cells subcutaneously into irradiated mice each cell type when obtained from immunized mice was capable of suppressing the growth of the specific tumor cells the results are discussed with respect to a possible specific immunologic function for macrophages in graft rejection
MED	effect of heterologous antiserum and complement on glycolysis of tumor cells the effect of heterologous antiserum and complement on glucose metabolism of rat ascites tumor cells was examined to clarify the mechanism of the cytotoxic effect of antibody 1 lactate production of the target cells was inhibited by the cooperation of antiserum and complement while no inhibition was observed when the cells were subjected to either antiserum or complement alone the inhibition of lactate production was observed under both acrobic and anacrobic conditions no effect of the antiserum and complement was observed on the oxygen consumption of the cells 2 the amount of antiserum necessary for the inhibition of lactate production of the cells was determined in the presence of a definite amount of complement and it was found that the degree of inhibition was not in parallel with the concentration of antiserum beyond a certain threshold on the other hand a parallelism was observed between the amount of complement and the rate of inhibition of lactate production when different amounts of complement were added to a definite amount of antiserum 3 similar inhibitory effects of the antiserum and complement on lactate production of the cells from glucose fructose 1 6 diphosphate and pyruvate suggested that the inhibition occurred toward the final step of glycolytic process of the cells
MED	soluble tissue antigens in human brain tumor and cerebrospinal fluid an a 2 globulin antigen present in human glioblastomas and immunologically identical with antigens present in human brain liver spleen and metastatic carcinoma cyst fluid has been described this protein antigen is not present in plasma wbc or normal csf it has been demonstrated in the csf of three of 27 patients with tumors of the central nervous system when present it may represent a specific tissue protein fraction contributed by either the tumor itself or the adjacent cns tissue the major protein components of normal and abnormal csf are derived from or at least antigenically identical to the plasma proteins
MED	the apparent immunofluorescence of tissue mast cells both rat mast cells and rat cosinophils exhibited fluorescence in blue violet light after treatment with fitc conjugated rabbit anti rat g globulin and in each cell this fluorescence was immunologically nonspecific whereas cosinophils fluoresced after treatment with fluorescein alone mast cells fluoresced only after treatment with a protein conjugate containing g globulin the phenomenon was observed in cells from different organs and the fluorescence was seen to be associated with the cytoplasmic granules normally present in these cells
MED	the determinants of cerebrospinal fluid po2 the effects of oxygen and carbon dioxide breathing in patients with chronic lung disease the lumbar cerebrospinal fluid po2 of some hypoxemic hypercapnic patients with chronic lung disease is the same as that of patients without chronic lung disease breathing 95 oxygen with 5 carbon dioxide increased lumbar cerebrospinal fluid po2 more than breathing 95 oxygen with 5 nitrogen the change in cerebrospinal fluid po2 is closely related to the change in arterial pco2 and this relationship is similar to the relationship between arterial pco2 and cerebral blood flow in patients with and without hypercapnia interpretation of these observations must be qualified by the following cisternal cerebrospinal fluid po2 differs from lumbar cerebrospinal fluid po2 in its response to breathing oxygen with carbon dioxide regulation of blood flow to the spinal cord and nerve roots is not known to be comparable to that of the brain and factors other than blood flow may have contributed to the changes of cerebrospinal fluid po2
MED	the behavior of lymphocytes in primary explants of human lung cancer in vitro the activity of lymphocytes within outgrowths from explanted tissue fragments of 20 human lung cancers has been studied the study included cancer bearing tissue explants from all cases and noncancerbearing lung tissue from 4 of the 20 cases five major categories of lymphocytic behavior were derived from the study namely 1 emigration and migration of lymphocytes from the explant 2 clustering of lymphocytes around target cells 3 ameboid transformation of lymphocytes 4 lymphocytic congregation and 5 emperipolesis criteria for these different lymphocytic activities have been amplified or introduced findings of particular interest were 1 the frequency of both via ble and nonviable lymphocytes within the vacuoles of other cells this observation is considered to be an absolute criterion for the recogni  tion of emperipolesis a subsequent inclusionbody appearance of the dead lymphocytes has been observed 2 the intimate relationship of ameboid forms of lymphocytes to selected cells resulting in a juxtanuclear and frequently unipolar crowding of one cell by numerous lymphocytes while nearby cells were totally devoid of ameboid lymphocytes reasons are given to support the impression that this phenomenon is re lated to sensitization there is also the possibility that the phenomenon may indicate that the lymphocyte is conditioned 3 the apparent entry of the lymphocyte into the cell has been recorded by timelapse cinematography a lymphocyte relationship to cancer cells was infrequently found although explants of 15 of the 20 cases produced identifiable cancer cells and lymphocytes emigrated from the explants of all 20 cases it is not apparent from this limited study whether this is a significant finding
MED	ventricular septal defect with aortic insufficiency a clinical and hemodynamic study of 18 proved cases eighteen patients with the combination of ventricular septal defect and aortic insufficiency were studied nine also had infundibular pulmonary stenosis seventeen were treated by open heart operations the physical findings were those of a typical ventricular defect murmur and thrill together with an aortic insufficiency blow and a wide pulse pressure a systolic murmur at the upper left sternal border with thrill is strongly suggestive of the additional lesion of infundibular pulmonary stenosis but the presence or absence of infundibular pulmonary stenosis was indicated most accurately at cardiac catheterization and on inspection at operation it was not of sufficient severity for signs of additional right ventricular hypertrophy to appear on the electrocardiogram retrograde aortography serves to demonstrate the severity of the aortic regurgitation the problem of the surgical correction of these lesions will be the subject of a separate communication
MED	radioisotope photoscanning as a diagnostic aid in cardiovascular disease a safe simple method for diagnosing pericardial effusion and aneurysm radioisotope scanning is a safe simple and useful method for the diagnosis of pericardial effusion and aortic aneurysm the whole body radiation dose approximately 25 millirads from 300 of i 131 sodium iodipamide is no greater than the dose received from a standard posteroanterior chest roentgenogram or a blood volume determination there are no side effects or complications from the procedure and it is well tolerated by the patient the scan can be repeated at intervals to assess progress of the disease or response to treatment cardiovascular scanning with radioactive isotopes can be recommended as a useful and safe diagnostic tool
MED	studies of hematology and bone marrow morphology in vitamin e deficient pigs forty four pigs were used in two experiments whose purpose was to produce a deficiency of vitamin e the anemia and changes in bone marrow morphology occurring in the vitamin e deficient state are described the hematologic disorders include low hemoglobin and hematocrit values leucocytosis and granulocytosis nuclear abnormalities were observed in the erythroid precursors in the bone marrow many of the cells being multinucleated giant multinucleated cells of megakaryocyte type were frequently found
MED	significance of blood groups in homotransplantation of marrow in the dog ten dogs were given 1 500 r whole body irradiation and an infusion of allogeneic marrow from a donor matched with respect to six erythrocyte antigens methotrexate was given to reduce secondary syndromes four dogs survived in a similar experiment with 10 dogs in which no effort was made to match donors and recipients three dogs survived it was concluded that matching of donor and recipient for these six red cell antigens did not increase significantly the longterm survival rate of lethally irradiated dogs with allogeneic marrow grafts
MED	radioautographic studies of bone marrow lymphocytes in vivo and in diffusion chamber cultures radioautography with tritiated thymidine has been utilized to examine the turnover rate and origin of small lymphocytes in the bone marrow of the guinea pig very few marrow lymphocytes were initially labeled by a single injection of tritiated thymidine but thereafter the number of labeled lym phocytes rapidly increased to high maximum levels at 3 days analysis of the labeling curves and grain counts indicates that the population of marrow lymphocytes is maintained in a dynamic steady state with an average turnover time of 3 days or less suspensions of bone marrow cells were isolated from the circulation within intraperitoneal diffusion chambers after short term labeling with tritiated thymidine in vivo although very few small lymphocytes were labeled when introduced into the diffusion chambers a considerable percentage became labeled during the subsequent culture period tritiated thymidine was also administered intravenously whilst excluded from one hind limb by the application of an occlusive compression bandage for 20 minutes very few labeled small lymphocytes were found after 72 hours in the tibial marrow of the initially occluded limb whereas the normal high percentage was labeled in the control tibial marrow these experiments do not demonstrate any large scale influx of small lymphocytes from the blood stream into the marrow parenchyma they suggest that newly formed small lymphocytes appear in the marrow as a result of the division of locally situated precursor cells but the mechanism of intramedullary lymphocytopoiesis is uncertain transitional cells intermediate in morphology between blast cells and small lymphocytes synthesize dna and are actively proliferative but they do not appear to account fully for the rate of lymphocyte production certain large undifferentiated labeled cells appeared in the bone marrow as a result of hematogenous migration some implications of these findings are discussed
MED	autoradiographic study on the origin and fate of small lymphoid cells in the dog bone marrow effect of femoral artery clamping during in vivo availability of h3 thymidine the origin and fate of small lymphoid cells in the dog bone marrow were studied autoradiographically by observing the effect of clamping of the femoral artery during in vivo availability of h3 thymidine heavily labeled small lymphoid cells appeared in the bone marrow of the clamped leg 3 hours after injection of the tracer and increased in number up to 6 days the labeling indices of these cells however were significantly lower than those of control marrow a possible interpretation is that dog bone marrow contains two populations of small lympho id cells one migrating into the marrow via the blood stream the other originating from local precursor cells within the marrow there was no evidence for a transformation of migrated small lymphoid cells into erythroblasts during the first 48 hours after injection of h3 thymidine
MED	the lymphocyte in guinea pig bone marrow the structure and distribution of lymphocytes in the bone marrow of normal 400 g guinea pigs have been studied by means of light microscopy electron microscopy and radioautography the study of structural organization by all three techniques confirms the morphological identity of the marrow small lymphocytes with small lymphocytes in other situations and affords added proof of the presence of a series of cells transitional in appearance between small lymphocytes and blast cells unlike the small lymphocytes transitional cells show evidence of dna synthesis marrow small lymphocytes and transitional cells are diffusely scattered throughout the parenchyma often situated in close proximity to the sinusoidal endothelium they are also found characteristically concentrated within some of the sinusoids this is termed lymphocyte loading the findings are discussed with particular reference to the possible origin interrelationship and fate of these cells
MED	surgical treatment of atrial septal defect under hypothermia the technique of inflow occlusion under 30 c hypothermia was adopted for direct visual correction in 133 consecutive cases of atrial septal defect of the secundum variety and the associated anomalies the use of extracorporeal circulation combined with hypothermia was reserved for the repair of two cases of ostium primum defects the over all operative mortality was 4 post operative evaluation showed that the results have been good in almost all patients including those with pulmonary hypertension since an ostium primum defect requires cardio pulmonary bypass for its closure the pre operative recognition of the defect is highly desirable in the selection of patients for operation and in planning the procedure itself the information derived from the clinical examination and appropriate diagnostic studies has been found to be consistently accurate in the pre operative differentiation of the primum from the secundum defect therefore the unexpected discovery of a primum defect at operation was not a problem in our experience open heart surgery under 30 c hypothermia for the repair of an atrial septal defect of the secundum type and the associated anomalies is a safe and practical technique and effectively corrects the anomaly with minimal risk
MED	internal cooling for general hypothermia a further presentation is offered on the advantageous use of intragastric temperature control as an adjunct in general hypothermia a device is described which accomplishes this end with no encountered deleterious side effects minimal technical involvement and minor expense observations are recorded on rates of temperature change according to sex weight and type of surgery performed
MED	late effects of regional renal hypothermia in summary one can safely conclude that no deleterious effects were created in dogs observed over a period of 3 years following renal ischemia of 6 hours duration protected by hypothermia the blood pressure failed to climb there was no evidence of azotemia and careful microscopic studies failed to reveal histological evidence of renal vascular or cardiac damage renal function as demonstrated by creatinine and pah was preserved and there was no delay in wound healing
MED	mesenteric vascular response to hypothermia 1 total and segmental resistances were studied in the mesenteries of 37 dogs and the effects of hypothermia changes in blood viscosity and epinephrine on these resistances were compared 2 cooling to 15 c caused an increased mesenteric resistance in 94 per cent of animals with approximately 90 per cent of the resistance rise contributed by the arterial segment small vessel resistance increased in 52 per cent there was no evidence of venous constriction 3 blood viscosity appeared to play a minor role 4 it is suggested that hemorrhagic necrosis of the bowel wall is due to intense vasoconstriction in the precapillary vessels with subsequent distal anoxia and cellular damage
MED	the response of dogs to perfusion and arrest of circulation at near zero cerebral temperatures 1 twenty six dogs were cooled by a whole body closed chest perfusion technique to end perfusion brain temperatures of 14 1 to 0 2 c inclusive 2 there were no deaths in the group of six dogs in which the end perfusion brain temperature was 10 0 c or higher 3 in the 17 dogs cooled to brain temperatures of 5 0 c or less there were nine deaths of which five occurred quickly from cardiovascular failure while four resulted from gross neurologic disturbances 4 there was no evidence of aortic incompetence during whole body closed chest hypothermic perfusion 5 the lower the temperature of the brain at the end of the cooling perfusion the greater was the passive transfer of heat from the environment
MED	effects of graded hemorrhage on cardiopulmonary functions of hypothermic dogs experiments were conducted on anesthetized dogs subjected to moderate hypothermia 28 c and then bled in percentages of the estimated blood volume respiratory work was not influenced by the degree of hemorrhage pulmonary ventilation respiratory rate and tidal volume were not influenced significantly as a result of blood withdrawal physiologic dead space as a percentage of tidal volume increased with hemorrhage oxygen consumption decreased as the hemorrhage was made more severe whereas carbon dioxide production was unchanged indicating a shift in the respiratory exchange ratio cardiac output decreased 78 per cent from control level when 35 per cent of the estimated blood volume was withdrawn systemic arterial pressures decreased markedly but heart rate was not changed as a result of blood withdrawal comparison of responses to hemorrhage in hypothermia and normothermia is discussed
MED	hypothermia in management of acute renal failure 1 prolonged hypothermia begun in the period immediately following the infusion of epinephrine into the renal artery appears to give partial protection against renal damage 2 shorter periods of hypothermia do not appear to be beneficial 3 prolonged hypothermia at 28 to 30 c has a mortality rate of 50 percent to 60 percent
MED	2803 effect of dosage on endotoxin induced changes in the reticuloendothelial system of rabbits tissues were removed from rabbits 4 and 24 hr following an i v injection of 5 25 or 200 ug of endotoxin explants of tissues from normal and injected animals were grown in a coagulated plasma medium and in medium containing 1 ug ml of endotoxin the migration and growth of cells were observed during the following week of incubation the inhibition or stimulation of cells of the reticuloendothelial system res at different host sites after endotoxin administration depended on the dosage and on the known capacity of different organs to take up circulating endotoxin macro  phage migration was suppressed in cultures of spleen removed 4 hr after a dose of hibited by 200 ug but macrophages in lymph node testis and thymus showed an in  crease in numbers in extent of migration and in phagocytic activity widespread res stimulation was seen in tissues removed 24 hr after the largest dose in ad  dition to the restoration of re cell activity in spleen and lung there was a marked increase in the migration of large phagocytic cells from bone marrow as well as other organs macrophages from endotoxin injected animals were as sensitive as normal macrophages to added endotoxin in vitro
MED	3075 vaccinia pneumonia in mice a light and electron microscopic and viral assay study swiss white mice between 2 and 4 days of age developed generalized vaccinia viral infection 2 to 7 days after intranasal inoculation gross and histologic evidence of pneumonia was seen in more than 80 of approximately 300 mice virus was re  covered in relatively high titers from the lungs 10 pfu per g during the per  iod when pneumonia developed viremia was also present but virus titers in the blood stream remained much below those in the lungs histologically vaccinia pneumonia was characterized by large swollen mononuclear cells giving rise to marked widening of alveolar septa only scattered neutrophils were noted usually in association with cell necrosis exudation of edema fluid and red cells into al  veoli was considered the result of viral replication and cytopathic effect on cells comprising alveolar septa various forms of vaccinia virus were observed by elec  tron microscopy within both type i and type ii alveolar lining cells capillary endothelial cells and interstitial cells within alveolar walls these infected inter  stitial cells were probably derived from fixed macrophages and were noted also around bronchioles virus particles were similarly observed in bronchiolar epi  thelium and surrounding smooth muscle cells the earliest pathologic ultrastruc  tural change noted in virus infected cells was intracellular edema evidenced by low electron density of the background cytoplasmic material and dilatation of the endoplasmic reticulum more extensive changes resulted in cell necrosis with release of virus particles into the extracellular space
MED	1161 electron microscopy of the bovine lungs lattice and lamellar structures in the alveolar lumen in an electron microscopic study of samples from the lungs of 20 normal cattle and from 4 with high mountain disease lattice and lamellar structures were obser  ved free in the alveolar lumens in 25 of the normal cattle and in 100 of those with high mountain disease in one specimen a lattice and lamellar structure was ob  served in a vacuole within an alveolar epithelial cell all others were extracellular the shape and dimensions of these lattice and lamellar structures were similar to those described by other workers in experiments involving intratracheal injections of silicon and oleic and linoleic acid this is the first report of the structures free in the alveolar lumens of apparently normal cattle
MED	1162 electron microscopy of the bovine lungs the blood air barrier in acute pulmonary emphysema electron microscopic studies of experimentally induced acute pulmonary emphy  sema in 2 cows yielded the following findings alveolar epithelial edema and cyto  lysis endothelial thinning and cytolysis excessive elastic and collagenous alveo  lar wall fibrosis hyperplasia of alveolar wall smooth muscle numerous intra  alveolar lattice and lamellar bodies hyaline membrane formation hypertrophied endothelial perikaryons numerous alveolar macrophages and alveolar epithelial secretion of an electron dense amorphous mass it was postulated that the lattice and lamellar bodies were a result of degenerating alveolar epithelial cells
MED	1560 the ultrastructure of the lungs of lambs the relation of osmiophilic inclusions and alveolar lining layer to fetal maturation and experimentally produced respiratory distress the lungs in 69 fetal and newborn lambs were studied osmiophilic inclusion bodies first appeared at about 121 days gestation and their total number increased with maturation normal surface activity of lung extracts was detectable a few days following the appearance of inclusion bodies the excretory nature of the type ii alveolar epithelial cell the phospholipid nature of the inclusion body content the decrease in the number of inclusion bodies and their loss of density associated with respiratory distress and with the loss of normal surface activity of lung ex  tracts provide strong evidence that inclusion bodies are the source of pulmonary surfactant a dense osmiophilic alveolar lining layer in mammals is described since the presence of such a layer is well correlated with surface tension values and the number of inclusions it is suggested that this layer consists of surface active substances the difficulty in detecting such an osmiophilic layer in other mammals is thought to be at least in part due to species differences in the compo  sition of materials constituting the pulmonary surfactant cytologic immaturity exists until lamb fetuses reach 135 days gestation this is considered to be the basis for the susceptibility of immature lambs to respiratory distress fibrin with 230 a periodicity is a component although a small one of hyaline membranes in lambs in view of the fact that mature fibrin appearing as bundles of fibrils is rare  ly found it is suggested that the bulk of the hyaline membrane is not a mature fi  brin but probably consists of polymers of fibrinogen and serum protein
MED	1685 differentiation of exfoliative broncho alveolar disease from desquamative interstitial pneumonia three cases are presented of the pulmonary disease described by liebow and asso  ciates and named by them desquamative interstitial pneumonia the cases support the existence of the entity and the contention that it had not been previously described a differential diagnosis between exfoliative bronchoalveolar disease and desquamative interstitial pneumonia is submitted clinical roentgenologic and histopathologic mani  festations are tabulated for each condition and the differences between them are em  phasized additional symptoms changes and phenomena not previously recorded are introduced the most distinctive differences between the 2 diseases were found in the histopathologic manifestations
MED	3831 lysosomes in the rat sciatic nerve following crush peripheral nerves undergoing degeneration are favorable material for studying the types origins and functions of lysosomes the following lysosomes are described a autophagic vacuoles in altered schwann cells within these vacuoles the myelin and much of the axoplasm which it encloses in the normal nerve are degraded wal  lerian degeneration the delimiting membranes of the vacuoles apparently form from myelin lamellae considered as possible sources of their acid phosphatase are golgi vesicles primary lysosomes lysosomes of the dense body type and the endo  plasmic reticulum which lies close to the vacuoles b mebranous bodies that accu  mulate focally in myelinated fibers in a zone extending 2 to 3 mm distal to the crush these appear to arise from the endoplasmic reticulum in which demonstrable acid phosphatase activity increases markedly within 2 hours after the nerve is crushed c autophagic vacuoles in the axoplasm of fibers proximal to the crush the break  down of organelles within these vacuoles may have significance for the reorganization of the axoplasm preparatory to regeneration d phagocytic vacuoles of altered schwann cells as myelin degeneration begins some axoplasm is exposed this is apparently engulfed by the filopodia of the schwann cells and degraded within the phagocytic vacuoles thus formed e multivesicular bodies in the axoplasm of myelina  ted fibers these are generally seen near the nodes of ranvier
MED	2431 histochemistry of surface epithelial and pleural mucins in mammalian lung the demonstration of sialomucin in alveolar cuboidal epithelium sialo  and sulfomucins have been demonstrated histochemically in the surface layer of the lung and pleura from rabbit syrian hamster guinea pig mouse and man sialomucin predominates in the distal bronchial tree and covers the alveolar epithelial surface the possible significance of these observations is discussed
MED	617 maturation of postnatal human lung and the idiopathic respiratory distress syndrome maturation and pathologic alterations of the lung in 19 newborn infants who died of idiopathic respiratory distress syndrome were studied by light and electron microscopy normal lungs from 6 fetuses and 11 new  borns served as controls in all infants with idiopathic respiratory distress syndrome respiratory bronchio  les and alveolar ducts usually presented the histologic pattern of mature lungs i e they were predominantly lined by type i cells which also formed the epithelial component of most blood air barriers well expanded alveoli exhibited a similar pattern whereas collapsed alveoli were lined by numerous type ii cells which par  ticipated in the formation of poorly developed blood air barriers the capacity of type ii cells to produce in  clusion bodies seemed to increase with survival beyond the 14th hr of age secretion of inclusion bodies and presumably surfactant into alveolar spaces did occur but only in the lungs of infants older than 2 days how  ever this process was not accompanied by reduction in the number of type ii cells per alveolus as in the nor  mal lung the distribution of pathologic changes in idio  pathic respiratory distress syndrome appeared to be determined by the degree of maturity of the air sacs structurally mature air sacs were associated with da  mage of epithelial lining and hyaline membrane forma  tion in contrast collapsed alveoli revealed an intact epithelial lining and marked septal edema but were free of hyaline membranes the findings of this study sug  gested that transudation of plasma through well develop  ed blood air barriers was responsible for epithelial damage and hyaline membrane formation in air sacs they also suggested that alveolar collapse and presuma  bly lack of surfactant were related to abnormal matura  tion of the epithelial lining and to septal edema
MED	903 lattice structures and osmiophilic bodies in the developing respiratory tissue of rats osmiophilic inclusions have been observed in the lungs of rats particularly in the 20 day rat embryo and newborn up to 3 days post partum these inclusions are present in the large alveolar cells as dense lamin  ated structures of variable size and configuration they generally consist of concentrically arranged membranes and have the appearance of myelin figures usually with a dense center these osmiophilic inclusions are fre  quently seen in direct contact with the cell membranes and the alveolar space the alveolar space contains numerous osmiophilic myelin figures which are thought to originate from the intracellular osmiophilic inclu  sions they may extrude through a channel formed in  side the cell or by rupture of the cell membrane secre  tion materials may occasionally be seen in the cyto  plasm of the large alveolar epithelial cells these cells appear to be in the process of degeneration their cell surfaces are disrupted and the cytoplasm is continuous with materials in the air space the lattice structure in the alveolar space may originate from the cytoplas  mic secretion material the cytoplasmic secretion ma  terial in the cell and the lattice structures in the air space disappear after the rats are 3 days old i t
MED	454 xanthogranuloma xanthoma of choroid plexus the origin of foamy xanthoma cells a case of a 3 month old infant with intense pro  liferation of choroidal epithelium with foamy cells a second similar case in a 9 month old infant with gener  alized glycogen storage disease and a case of a 51 year  old male with bilateral xanthogranuloma of choroid plexus and proliferation of the choroidal epithelial cells are discussed the pathogenesis of the foamy xanthoma cells in the stroma of the choroid plexus particularly is discussed the authors believe that the origin of foamy cells and the mode of formation of such a xanthogranuloma can be explained by the proliferative capability and the phagocytic activity of the choroid epithelium choroidal epithelial cells can be regarded as fixed macrophages which becomes wandering phagocytes after detachment disintegration of these foamy cells then releases the lipid content into the interstitium and provokes a re  sponse of macrophages and multinucleated giant cells of the foreign body type hemorrhage is also considered as a factor involved in the formation of xanthogranuloma
MED	4 mixed hematopoietic and pulmonary origin of alveolar macrophages as demonstrated by chromosome markers the origin of alveolar macrophages was investiga  ted in mouse chimeras in which the hematopoietic cells could be identified by marker chromosomes by chro  mosome analysis it was found that in both normal lungs and in lungs exposed to an irritant approximately two  thirds of the dividing cells which could be recovered by lung washing arose from the hematopoietic system and one third were of pulmonary origin
MED	632 pulmonary alveolar proteinosis a study using enzyme histochemistry electron microscopy and surface tension measurement lung biopsies from 4 patients with pulmonary al  veolar proteinosis were studied using histochemical me  thods electron microscopy and surface tension mea  surement the lipid rich intraalveolar fluid contained material with the staining reactions and ultrastructure of phospholipid although many alveoli were lined by enzymatically active secreting granular pneumonocy  tes extracts of proteinotic tissue were not surface active and in fact inhibited normal surfactant some of the cells free in the intraalveolar material were de  generating sloughed granular pneumonocytes at the margins of the lesions were lipid filled macrophages which appear to play a role in the removal of the mate  rial these observations indicate that alveolar protein  osis is not a primary overproduction of surfactant and are consistent with the concept that the alveolar clear  ing process is defective in this disease
MED	1688 surface phenomena in lungs in health and disease in summary the authors have attempted to bring together the multiple observations which seem germane to the understanding of surface phenomena in lungs in health and disease to this end the contributions of anatomists and pathologists on the fine structure of alveolar cells and their lining are fundamental the concepts of alveolar stability required the special insights of physiologists who were concerned with the causes of bubble stability as they related to the particular problems posed by a lung of several millions of bubbles arranged in parallel soon the contributions of the chemists became significant as methods of identification and assay of the al  veolar lining material were of interest clinicians asked what relevance these studies had to atelectasis as it occurs in disease and soon the question of when the surfac  tant appeared in development occurred to those concerned with premature infants students of metabolism began to focus on the lung as a site of phospholipid synthesis and their tools seem most promising at this time in unearthing possible errors in metabolism which may express themselves in disease surgeons who undertake per  fusion of the isolated lung ask the requirements of that organ with respect to the nutrients and environment of the alveolar cells and anesthesiologists inquire into the possibilities of mechanical injury to the alveoli during artificial respiration the problems posed to the reviewers of a subject which touches so many disciplines are obvious doubtless some pertinent studies have been omitted although uninten  tionally others may have been misinterpreted through lack of qualifications as spe  cialists in all specialties the authors hope they have provided evidence that the forces of surface tension cannot be ignored in an organ with an air liquid interface of some 70 m2 they further hope they have described some of the properties of the film at the alveolar air interface which operate to produce stability of the alveoli they hold the belief that study of the metabolism of the alveolar lining layer will further their understanding of a number of disease processes in which it may be altered and lastly they hope for much closer communication between workers in many disciplines who can elucidate this remarkable subject best through cooperative studies
MED	1689 alterations in pulmonary surface active lipids during ex  posure to increased oxygen tension the syndrome of progressive respiratory distress pulmonary edema and increased pulmonary surface tension was induced in 8 dogs by exposure to oxygen tensions greater than 550 mm hg for 44 5 and 52 hours pulmonary surfactant was extracted by endobronchial washing for measurement of lipid composition and surface activity five dogs developed respiratory distress without pulmonary edema in these dogs endobronchial wash surface tension was normal or slightly increased and total lipid distribution was essentially normal esterified fatty acids in the lecithin frac  tion were consistently altered with a reduction in palmitate and total saturated fatty acids three dogs developed pulmonary edema with increased surface tension in  creased total lipid and protein and relatively decreased total phospholipid in the endobronchial washings esterified fatty acids in the lecithin fraction were marked  ly altered with palmitate levels about 1 3 normal esterified arachidonate was pre  sent that was attributed to intra alveolar plasma electron micrographs of the lung after oxygen exposure showed thickening of alveolar basement membrane and altera  tions in the structure of the lamellar bodies of the type ii alveolar epithelial cells
MED	3805 cisternal fluid oxygen tension in man measurement of cerebral oxygen tension in man has been hampered by technical dif  ficulties the authors present a method in which a beckman microelectrode was introduced into the cisterna magna and oxygen tension measured the hypothesis being that measurement of oxygen tension in a fluid which equilibrates with the average cerebral oxygen tension should give reliable measure of cerebral oxygen tension in their subjects inhalation of pure oxygen produced an increase in the oxygen tension in the cisternal fluid as well as in the arterial blood without any alteration of the oxygen tension in the bulb of the internal jugular vein whereas inhalation of 95 oxygen and 5 carbon dioxide increased the oxygen tension in the cisternal fluid as well as in the arterial and venous blood 5 carbon dioxide in air produced an increase in the cisternal oxygen tension a fall in arterial blood pressure associated with the introduction of the suboccipital needle was accom  panied by a decrease in cisternal oxygen tension which then rose simultaneously with the increase in arterial blood pressure that followed infusion of dextran intravenous injection of xanthinol niacinate induced in all patients a more or less pronounced fall in arterial blood pressure and at the same time the cisternal oxygen tension fell administration of aramine was associated with a rise in arterial blood pressure plus a rise in cisternal oxygen tension
MED	4181 cerebrospinal fluid in man native to high altitude csf ph was shown in a prior report to remain essentially constant during 8 days of acclimatization to 3 800 m in order to further evaluate the possible role of csf acid base equilibria in the regulation of respiration 20 peruvian andean na  tives were studied at altitudes of 3 720 4 820 m in 10 subjects at 3 720 m means were csf ph 7 327 pco 43 hco3 21 5 na 136 k 2 6 cl 124 lactate 30 mg 100 ml arterial blood ph 7 43 pco 32 5 hco3 21 3 na 136 k 4 2 cl 107 hematocrit 49 sao 89 6 in 6 subjects at 4 545 m and 4 at 4 820 m csf values were not significantly different mean arterial pco was 32 6 and 32 3 respectively the only significant variations with altitude were the expected lowering of pao to 47 and 43 5 mm hg and of sao to 84 2 and 80 7 and increase of hematocrit to 67 and 75 respectively the natives differed from recently acclimatized sea  level residents in showing less ventilation higher pco in response to the ex  isting hypoxia and less alkaline arterial blood the difference appears to relate to peripheral chemoreceptor response to hypoxia rather than central medullary chemoreceptor
MED	1116 na k ca mg and cl concentrations in choroid plexus fluid and cisternal fluid compared with plasma ultrafiltrate in 7 cats the concentrations of na k ca mg and cl were measured in plasma ultrafiltrate newly formed choroid plexus fluid and cisterna magna fluid the choroid plexus fluid did not differ from plasma ultrafiltrate in cl and k concentra  tion but contained higher na markedly higher mg and lower ca concentrations than the ultrafiltrate cisterna magna fluid differed from the ultrafiltrate with respect to all 5 electrolytes containing higher concentrations of cl na and mg and lower concentrations of k and ca it differed from choroid plexus fluid in con  taining a higher concentration of cl but lower concentrations of k ca and mg hco3 concentration calculated on the basis of the charge balance was 7 mm kg h2o higher in choroid plexus fluid than in cisterna magna fluid suggesting an ele  vated ph at the former site without measurement of the potential difference be  tween the csf and plasma definitive conclusions could not be drawn as to which cations were actively transported the fact that the distribution ratio between cerebro  spinal fluid and ultrafiltrate of one divalent cation was in the opposite direction from that of the other and that this was also true of the monovalent cations was taken as evidence that the mechanisms involved in cation transfer are quite selec  tive though not proven active transport was considered the most likely explana  tion of these findings the data suggest that these specific transfer mechanisms subserve a homeostatic function with regard to mg and k in the cerebrospinal fluid
MED	3230 cerebral hemodynamics blood gases and electrolytes during breath holding and the valsalva maneuver continuous recordings of arterial and internal jugular blood oxygen tension oxy  gen saturation carbon dioxide tension ph sodium and potassium together with peco2 blood pressure and electroencephalogram were obtained to compare the effects of inspiratory and expiratory breath holding and the valsalva maneuver on the cerebral circulation and cerebral oxygen availability in man during the inter  val of tolerated breath holding for 69 seconds or less jugular venous oxygen tension was increased owing to increased cerebral blood flow resulting from an increase of arterial carbon dioxide tension there was a statistically significant correlation between changes in jpo2 and paco2 which proved to be more or less linear for both increases and decreases of paco2 4 mm above and below control levels no threshold was found for changes in paco2 altering effective cerebral perfusion and cerebral venous po2 extremely small changes in paco2 less than 1 mm hg altered cerebral oxygen availability within 10 to 20 seconds during the valsalva maneuver a consistent reduction of jugular oxygen tension was found associated with the sudden fall in arterial blood pressure and reduction of arterial carbon dioxide tension the rapid changes in cerebral hemodynamics and cerebral oxy  gen availability during the procedure are briefly discussed
MED	2344 respiratory and cardiovascular changes during rapid spon  taneous variations of ventricular fluid pressure in pa  tients with intracranial hypertension in patients with intracranial hypertension the ventricular fluid pressure vfp curve is characterized by 3 main forms of spontaneous variations two of these forms are of a rhythmical nature and are here called 1 per minute waves and 6  per minute waves respectively in accordance with the dominating frequency the third form   irregularly appearing waves of large amplitude and duration   is called plateau waves in accordance with the usual shape of the fluctuations respiratory and cardio vascular changes accompanying these variations of the vfp were studied by simultaneous recording in various combinations of the vfp the pulmonary ventilation the pco2 of the expiratory air the arterial and the venous blood pressure and the pulse frequency it was found that the rhythmic vfp vari  ations of the 1 per minute type occurred synchronously with the respiratory peri  ods in cheyne stokes breathing synchronously appearing variations in systemic blood pressure in pulse frequency as well as in consciousness and in muscular tone of the limbs were also noted the respiratory midposition shifted towards the inspiratory side during the periods of hyperpnoea the 6 per minute waves were entirely synchronous with variations in the systemic arterial blood pressure of the traube hering mayer type long sequences of these waves were observed only when the vfp level was considerably elevated the plateau waves were not accom  panied by corresponding elevations of the arterial or venous systemic blood pres  sure simultaneously with the crests of the plateau waves sudden changes often occurred in the pulse frequency from bradycardia to tachycardia and in the res  piratory pattern sometimes also in the degree of consciousness and in the muscu  lar tone there were also long sequences of 6 per minute waves the deep irre  gular breathing seen in this stage induced a considerable hypocapnia preceeding the final critical fall in the vfp ending the plateau wave in most instances how  ever this fall did not begin until several minutes after the appearance of the hypo  capnia
MED	82 central nervous system lesions in rats exposed to oxygen at high pressure adult female rats paralyzed by repeated exposures to oxygen at high pressure were found to have cns le  sions of 2 types 1 focal necrosis of individual neurons within certain nuclear groups and 2 complete or partial necrosis of nuclear groups with frequent damage to mye  lin axons and glia in the area involved both types were usually bilateral and symmetrical lesions of the first type were found consistently in the superior olivary complex ventral cochlear nuclei and nuclei of the spinal tract of cranial nerve v lesions of the second type were found consistently in the substantia nigra and globus pal  lidus were frequent in the rhinencephalon and never occurred in the neocortex
MED	747 electrode size and tissue po2 measurement in rats exposed to air or high pressure oxygen a comparison has been made of values of po2 recorded in several rat tissues with 60 u or 330 u flexible gold electrodes although qualitatively both sizes of elec  trodes give similar results the quantitative values of po2 differ such large differ  ences as are found in some cases between electrodes varying only in physical di  mensions are thought to reflect the amount of trauma caused in the tissue under in  vestigation due to electrode insertion errors in po2 estimations due to tissue da  mage are considered to outweigh any other errors such as those due to electrode calibration soft highly vascular tissues such as liver kidney and spleen which show macroscopic bruising over quite a large area when electrodes are inserted show the greatest difference in estimations of the po2 value recordings of tissue po2 were made while animals breathed air and when compressed to 4 or 5 atm in pure oxygen and the pattern of response of tissue po2 to such exposure of the ani  mal to high pressures of oxygen is described
MED	3384 adrenergic effects in splenic po2 of rats in air or oxygen at 5 atmospheres oxygen tensions have been measured in the spleens of rats breathing air and during exposure of the animals to 5 atm abs of oxygen hpo the response of splenic po2 to compression was complex usually reaching a peak value immediately after com  pression then falling to a lower value this form of response has been termed a hump response after adrenalectomy or bretylium tosylate injection the hump res  ponse of po2 after compression was almost abolished and the values of splenic po2 at 5 atm were considerably higher than in control animals a combination of adrena  lectomy and bretylium tosylate also markedly reduced the number of hump responses but unexpectedly significantly lowered splenic oxygen tensions both when the ani  mals were under ambient conditions or at 5 atm of oxygen cardiac rate and blood pressure were studied in an attempt to find the explanation of this latter effect and while blood pressure was the same in adrenalectomized rats and control rats after bretylium injection adrenalectomy potentiated the bradycardia produced by brety  lium tosylate
MED	10642 the effects of antioxidants on high pressure oxygen toxicity several commonly used antioxidants have been tested for their effect against poison  ing due to high pressures of oxygen ohp the tests used were preconclusive pe  riod and survival time of mice at 5 atm absolute oxygen lung damage in rats ex  posed to 5 atm oxygen for 1 hr and post ohp paralysis in rats following deep pentobarbital na anesthesia and ohp at 4 atm for 30 min 2 5 bis 1 1 dimethyl  propyl hydroquinone gave excellent protection against ohp toxicity in all tests and several other antioxidants also protected against ohp toxicity but their potency and effectiveness varied for the different criteria of oxygen poisoning tested in the experiments
MED	3716 glycolytic control mechanisms i inhibition of glycolysis by acetate and pyruvate in the isolated perfused rat heart acetate or pyruvate had similar effects on the over all metabolism of glucose gly  colytic flux was decreased in both the presence and absence of insulin glucose oxidation was greatly decreased and the conversion of glucose to glycogen and lac  tate was promoted glucose phosphorylation was decreased in the presence but not in the absence of insulin hexokinase phosphofructokinase glyceraldehyde phos  phate dehydrogenase and pyruvic kinase are far displaced from equilibrium while the other enzymic steps of glycolysis are maintained either at equilibrium or fairly close to equilibrium in different metabolic situations glycolytic flux may be affec  ted by those steps which are far displaced from equilibrium increased levels of the hexose monophosphates and decreased levels of the other glycolytic inter  mediates between fructose 1 6 diphosphate and pyruvate after the addition of 10 mm acetate indicate that glycolytic flux was decreased by inhibition of phosphofructo  kinase after the addition of 10 mm pyruvate fructose 1 6 diphosphate and triose  phosphate accumulated as a result of an inhibition of either glyceraldehyde phosphate dehydrogenase or phosphoglyceric kinase acetate had little effect on the total con  tent of oxidized or reduced di  or triphosphopyridine nucleotides but slightly de  creased the ratio of nad to nadh2 in the cytoplasm as estimated from the ratios of lactate to pyruvate and a glycerophosphate to dihydroxyacetone phosphate pyru  vate increased the total content of nadh2 and nadph2 as shown both by an increase of fluorescence in the intact heart and by tissue analyses but the ratio of nad to nadii2 in the cytoplasm was greatly increased these results demonstrate com  partmentation of pyridine nucleotides between cytoplasm and mitochondria in the intact cell after the addition of acetate citrate was the only intermediate of the citric acid cycle which increased greatly in amount while oxaloacetate levels de  creased after the addition of pyruvate the levels of citrate a ketoglutarate ma  late and oxaloacetate were all greatly elevated the glutamic oxaloacetate trans  aminase reaction as measured from the total contents of the reactants in the tissue remained close to equilibrium changes in the concentrations of the adenine nu  cleotides were insufficient to account for the inhibition of phosphofructokinase but the results are consistent with control at this step being mediated by citrate
MED	244 oxygen tension in human malignant disease under hyperbaric conditions oxygen tensions were recorded continuously in tumours and normal tissues of 34 pa  tients pressurized in pure oxygen to 4 atmospheres absolute mean rises to 620 mm hg and 320 mm hg for tumours and normal tissues respectively were recorded with patients breathing air at atmospheric pressure 22 90 24 of tumour elec  trodes registered po2values of less than 4 mm hg compared to only 2 39 5 of normal tissue electrodes the results obtained suggest that oxygen polarography as a meth  od for determining po2 in solid tissues in vivo is complicated by many artefacts   particularly tissue damage due to electrode trauma   which reduce its value to clin  ical research concerned with accurate information of absolute po2 values in intact tissues
MED	7839 cortical ph and the blood brain barrier a method was described for measuring the ph dc and ac potentials concurrently on the cerebral cortex of the adult cat under conditions of controlled ventilation kittens and rabbits were also studied the cortical ph response to i v nahco3 was acidic and was accompanied by a dc negativity while the blood became alkaline such an acidic response was present in the rabbit and kitten it was not present in a number of other tissues in the cat including the dura the cortical acidic response was not affected qualitatively by i v acetazolamide prolonged hypoxia or 10 v v co2 it was reduced reversibly by 20 v v co2 it was not affected by removal of the arachnoid membrane the cortical ph response to an i v nh4 salt solution was complex nh4c1 did not produce an alkaline response the cortical ph response to an alkaline or an acidic sodium phosphate solution was augmented but not changed in its direction following treatment of the cortex with n butanol the results were interpreted in terms of a restriction of hco3  by the blood brain barrier through which co2 can pass this restriction is probably non specific for inorganic ions and perhaps for other substances it does not appear to be related to a low cerebral extracellular space and is independent of substantial oxidative metabolism
MED	7083 brain damage and paralysis in animals exposed to high pressure oxygen   pharmacological and biochemical observations single exposures of high pressure oxygen ohp at 30 66 gauge pressure caused cns damage and paralysis in rats and mice but guinea pigs rabbits and man did not show such sequelae the cns damage in rats was greatly increased by cns de  pressant drugs pentobarbital paraldehyde n2o and phencyclidine given before ex  posure to ohp the cns lesions were also potentiated by raised respired pco2 by acetazolamide and by nh4c1 whilst protection was afforded by methaemoglobinae  mia by tham by 2 4 dinitrophenol and by serotonin against the barbiturate and co2 potentiation of ohp brain damage ohp induced brain damage was not modified by hypothermia cp2 electroconvulsive shock treatment during ohp cerebral x  irradiation adrenalectomy or cortisone slow decompression rates spinal block with local anaesthetic conditioning of rats to ohp hyper  and hypoglycaemia or alterations in tissue histamine levels the results are discussed in relation to pos  sible biochemical mechanisms and theories of oxygen poisoning
MED	8914 the effect of hypoxia on oxygen consumption of cerebral cortex liver slices and of diaphragm in vitro during post  natal development of the rat oxygen consumption of slices from the liver and cerebral cortex and of the cut dia  phragm was determined in rats aged 5 10 14 20 and 25 days and in adult animals under hypoxic conditions gas phase 10 oxygen 90 nitrogen oxygen consumption of liver slices and diaghragm is decreased by about 25 in all age groups hypoxia however did not affect oxygen consumption of slices of the cortex from 5 day old rats and its inhibitory effect only appeared later as the normal oxygen consumption started to rise the inhibitory effect of hypoxia was greatest in adult animals
MED	5407 hypoxic hypercapnic interaction in subjects with bilateral cerebral dysfunction to analyze cerebral influences modifying autonomic respiratory responses the authors compared normals and patients with bilateral pyramidal tract disease for their ventilatory response to hypoxia and hypoxia hypercapnia during eucapnia the 2 groups showed similar hypoxic responses during hypercapnia the ventilatory response to hypoxia was greater in the brain damaged subjects this apparent aug  mentation however was due entirely to anoxia interacting with an abnormally fa  cilitated carbon dioxide sensitivity compared with normals brain damaged patients at pao 90 100 mm hg showed an 85 greater co2 response and at pao 50mm hg showed a 79 greater co2 response since cerebral dysfunction facilitated the ven  tilatory response to hypoxia hypercapnia combined but not the response to hypoxia alone the results imply that the 2 respiratory stimuli interact centrally rather than peripherally
MED	3917 plasma free fatty acid and blood sugar levels in newborn infants and their mothers simultaneous plasma free fatty acid ffa and blood sugar levels were determined for fasting newborn infants during the first 24 hours of life for their cord bloods and for their mothers at delivery the following observations were made in con  trol infants the mean ffa level rose about three times the cord level after birth and was accompanied by a 25 drop in the mean blood sugar level thereafter the mean blood sugar level remained relatively constant but the mean ffa level varied from 2 5 to 3 times the cord level there was no significant correlation between the length of maternal fasting prior to delivery and the infant ffa level there was however a significant negative correlation between the length of maternal fasting prior to delivery and the infant blood sugar level at 24 hours of age high ffa levels occurred in the infants of obese mothers and low levels were observed in infants with delayed respirations in infants of preeclamptic mothers and in infants of diabetic mothers
MED	2933 the essential fatty acid requirement of infants and the assessment of their dietary intake of linoleate by serum fatty acid analysis the content of polyunsaturated fatty acids in serum total fatty acids was related to the dietary intake of linoleate in 243 infants two to four months of age and in 197 infants eleven to twelve months of age the curves relating triene tetraene ratio to dietary linoleate indicated approximately 1 per cent of total calories as minimal linoleate requirement the exponential equations relating dienoic trienoic and tetraenoic acids to dietary linoleate were derived by computer methods these yielded constants from which the minimal nutrient requirement could be calculated the best estimates were obtained from the triene and tetraene data for two to four months old infants and were found to be approximately 1 4 per cent of the caloric intake the nutritive status with respect to linoleate may be estimated by means of logarithmic regression equations the equation for two to four months old infants is log 10 dietary linoleate  1 087 0 0432 di   tri tetra the data for eleven to twelve months old infants were found to have greater scatter and give lower triene tetraene ratios at comparable linoleate intakes the scatter and displacement are considered to be due to supplements of solid food to the basic diet not considered in the calculated dietary linoleate
MED	74 analytic study of the a  and b lipoprotein micellar groups and of nonesterified fatty acids of the plasma in normal pregnancy an analytical study has been made on 39 patients using a chemical method which allows the simultaneous detailed evaluation of the lipidic and a  and b liproproteinic fractions of the plasma in addition the non esterified fatty acids have been titrated the b proteins and the uric acid assayed and numerous indices and deducible ratios made from the data obtained the existence of quantitative dyslipidemia has been proven starting gradually especially in the 4th 5th month of pregnancy and most  ly regarding the b lipoproteins prevalently the slow subfractions greater increase of glycerides than phosphatides and cholesterol but with a non proportional in  crease of b proteins lower proteinic content it has moreover been noted that there is a prevalent rise of free cholesterol in the fraction of b lipoproteins with a reduction of the total esterification coefficient the morphological picture of the lipidic rate in pregnancy shows characteristics which according to the authors are like those to be seen in the lipidic rate of male presenility
MED	75 behavior of polyunsaturated fatty acids in physiological pregnancy by the enzymatic lipoxidase method of macgee et al the author measured polyun  satured fatty acids p f a in healthy pregnant women at full term of pregnancy before labour there are in the blood 75 95 mg of p f a i e 10 15 more than in non pregnant women during labour p f a increase very much 100 137 mg about 50 more than before labour
MED	5196 effects of nutritional deficiency of unsaturated fats on the distribution of fatty acids in rat liver mitochondrial phospholipids the fatty acid composition of liver mitochondrial phospholipids from rats rendered deficient in essential unsaturated fatty acids has been determined and compared with that of rats fed a diet containing corn oil in addition to marked reductions in the amounts of linoleic and arachidonic acids esterified at the b position of ethanol  amine  inositol  and choline glycerophosphatides the deficiency resulted in ex  tensive changes in the distribution of saturated acids at both the a  and b positions palmitoleic and oleic acids were increased in amount in fat deficiency and large amounts of docosatrienoic acids appeared in these 3 phospholipids the fatty acids of the sphingomyelins were not altered as a result of essential fatty acid deficiency the data demonstrate that each phospholipid is unique in the way in which its fatty acid moieties change in response to feeding a fat deficient diet
MED	3204 interventricular septal defects with aortic insufficiency sanchez f  villaran e the coincidence of these 2 malformations permits their diagnosis provided that a careful evaluation is made of the hemodynamic and oximetric data on the basis of specific auscultatory features even then a differentiation from other cardiopathies patent ductus arteriosus with without pulmonary hypertension aortopulmonary sep  tal defect interventricular communication truncus arteriosus aneurysm of the sinus aortae ruptured into right cavities   is not simple for this an analysis of the course of the syndrome together with the information supplied by phonocardiography catheterization angiocardiography radiology and ecg in this order of importance are indispensable an analysis is made of 5 cases in which in the absence of ana  tomical confirmation concrete data were obtained on which to base the diagnosis
MED	2579 measurement of aortic regurgitation by upstream sampling with continuous infusion of indicator a direct and theoretically valid method for the measurement of aortic regurgitation involves the recording of indicator concentrations from the left ventricle and a down  stream site during aortic root injection however this method has yielded erratic results when applied to man in the authors laboratory when using the sudden in  jection technique therefore the upstream sampling method using continuous in  fusion of indicator was evaluated in 18 patients with aortic regurgitation during retrograde aortic and transseptal left ventricular catheterization the continuous infusion technique was compared with the technique of sudden injection in 10 patients and with aortic valvulography in 14 patients measurements of forward flow obtained with continuous infusions into the aortic root were not significantly different from measurements obtained with sudden injections into the pulmonary artery recordings of indicator concentrations from the left ventricle during continuous infusions into the aortic root demonstrated readily evident equilibrium plateaus the resultant measurements of regurgitant flow were highly reproducible and not impaired by nonsimultaneity of upstream and downstream sampling the percentage error of estimate at 95 confidence limits was 22 of the measurement for regurgitant flow 13 for total flow and 9 for the regurgitant fraction of total flow the correspond  ing errors of estimate for the sudden injection technique were 4 times larger re  gurgitant flow by the continuous infusion method ranged from 0 8 30 0 l min total flow from 3 0 36 0 l min and the regurgitant fraction of total flow from 12 86 ranking of patients by the magnitudes of regurgitant and total flow did not correspond to ranking by angiographic criteria of severity however an excellent correlation prevailed between angiographic grade and the regurgitant fraction of total flow demonstrating that this variable is the most meaningful expression of severity the correlation 0 997 between the angiographic grade and the regurgitant fraction measured by the continuous infusion technique was clearly superior to that obtained with the sudden injection technique 0 894 mild regurgitation was equivalent to a regurgitant fraction of 25 moderate regurgitation to a fraction of 25 50 moderately severe regurgitation to a fraction of 50 75 and severe regurgitation to a fraction of 75 it is concluded that the upstream sampling method during con  tinuous infusion of indicator because of its sensitivity reliability applicability to multiple measurements and validity in the presence of mitral regurgitation is the most useful method for quantifying aortic regurgitation in man
MED	2950 aortico left ventricular tunnel a cause of massive aortic regurgitation and of intracardiac aneurysm the clinical roentgenographic hemodynamic and pathologic findings in a 14 year  old boy with aortico left ventricular tunnel are presented the accessory channel between the aorta and left ventricle resulted in massive aortic regurgitation and the portion of the tunnel which traversed the ventricular septum was aneurysmal displaced the posterior wall of the right ventricle and caused severe obstruction to right ventricular outflow the presence of associated cardiovascular anomalies in this and previously reported cases suggests that the malformation is congenital rather than acquired the clinical and hemodynamic manifestations of aortico left ventricular tunnel are indistinguishable from those observed with the more common forms of aortic regurgitation and the correct diagnosis can be established only by thoracic aortography the malformation is usually recognized in childhood since aortic regurgitant flow can be abolished by simple closure of the aortic ostium and without aortic valve replacement the indications for operative treatment differ from those which apply in aortic regurgitation due to a valvular anomaly
MED	502 the haemodynamic implications of the bisferiens pulse a bisferiens carotid arterial displacement pulse was recorded in 10 patients with severe aortic valvular disease the braunwald test indicated that moderately severe severe or gross aortic regurgitation was present in each the absence of a peak systolic aortic pressure gradient in certain cases particularly in those with the most severe regurgitation suggested their freedom from an element of stenosis the anacrotic wave and the peak of the aortic pressure pulse were found to coincide with the percussion and the tidal waves of the simultaneously recorded carotid ar  terial displacement curves it is suggested that amplitude of the peak of the anacro  tic wave is proportional to the rate of change of momentum of the ejected blood and that the amplitude of the corresponding percussion wave of displacement is modified by the distensibility of the artery the depth and shape of the trough between the two peaks is thought to depend upon the magnitude and slope of the two waves rather than upon a venturi effect it is suggested that the condition of the arterial wall the dia  stolic blood pressure and the stroke volume can influence the pulse sufficiently to preclude its use as a simple guide to the nature of the aortic valve lesion
MED	2753 left ventricular function following replacement of the aortic valve hemodynamic responses to muscular exercise evaluations of left ventricular myocardial function were carried out in 14 patients 4 16 mth after stenotic or regurgitant malformations of the aortic valve had been corrected by valve replacement the circulatory responses to exercise judged by the increases in cardiac output in relation to the increases in oxygen consumption were normal or only mildly reduced in 12 patients in 5 patients the relationships between the change in the left ventricular end diastolic pressure and the alteration in the stroke volume were also normal a fall or an increase in left ventricular end diastolic pressure of less than 3 mm hg being accompanied by an increase in stroke volume in 8 patients however abnormal increases in the left ventricular end diastolic pressure occurred during exercise and in 4 the left ventricular end  diastolic pressure was increased to levels above 12 mm hg variable alterations in the stroke volume accompanied these increases in end diastolic pressure it is suggested that in the 3 patients who exhibited simultaneous increases in left ven  tricular end diastolic pressure and stroke volume the changes were either a mani  festation of the frank starling mechanism or primarily the result of a positive inotropic influence in the 5 patients who exhibited increases in left ventricular end diastolic pressure but no change or a fall in stroke volume it is proposed that a distinct depression of left ventricular performance was present thus while the cardiac output response was adequate to meet the stress of exercise in the majority of the patients studied following aortic valve replacement determination of the relationship between the left ventricular end diastolic pressure and the stroke volume permitted the detection of abnormalities in the function of the left ventricle
MED	2497 pulmonary atresia with intact ventricular septum when the pulmonary valve is atretic and the ventricular septum intact the right ventricle usually consists of a small chamber with a very thick wall capable of de  veloping high pressure this pathologic picture is associated with clinical findings similar to those in tricuspid atresia cyanosis decreased pulmonary flow left ven  tricular preponderance on the electrocardiogram and early death the diagnosis may be confirmed by heart catheterization and selective angiocardiography with in  jection into the right ventricle but the risk is great surgery has never been suc  cessful in the past but because of the equally hopeless prognosis on medical treat  ment attempts should continue to be made anastomosis of the superior vena cava to the right pulmonary artery appears to offer hope of success in the future
MED	1635 intra atrial pressure measurement and electrocardiography in the detailed diagnosis of atrial septal defect after discussing the possibilities and limitations of different methods for identifying the anatomical type of atrial septal defect the authors suggest a more useful new method this consists in simultaneous recording of both the pressure curve and endocavitary electrocardiogram during withdrawal of the catheter from the left into the right atrium in the ostium primum type the septal foramen has no infe  rior margin and the point of the catheter during retraction unlike in the ostium secundum type rests on the intermediate section of the atrioventricular septum the endocavitary electrocardiogram in the zone of passage between the two atria shows the typical pattern of the intermediate section of the atrioventricular septum the pressure curve may show a pattern of the atrial of intravalvular type
MED	1636 ventricular septal aneurysms a report of two cases two cases of ventriuclar cuptal aneurysm are reported one in the membranous and one in the muscular portion the diagnosis was made by selective left ventricular angiogra  phy it is suggested that these cases represent spontaneous closure of a ventricular septal defect with weakness and aneurysmal formation due to the high left ventricular pressure both are asymptomatic and hemodynamically within normal limits surgical repair of the aneurysms is not considered necessary
MED	1642 electrode catheters and the diagnosis of ebsteins anomaly of the tricuspid valve the successful surgical treatment of ebsteins anomaly calls for accurate pre ope  rative assessment of the nature and severity of the tricuspid valvular lesion the increased risk of cardiac catheterization in this condition has been matched by in  creased experience of intracardiac techniques and provided the examination is in skilled hands patients with ebsteins anomaly should be investigated in the same way as those with any other serious congenital heart lesion for whom surgery is con  templated the diagnostic value of electrode catheters is discussed and the intra  cardiac electrocardiographic features of ebsteins anomaly are illustrated false positive and false negative records are demonstrated and the mechanism of their production is explained it is concluded that though helpful intracardiac electro  cardiographic evidence should be regarded as confirmatory rather than diagnostic records made with electrode catheters during cardiac catheterization should be con  sidered only along with the other clinical electrocardiographic and radiological features of the case and should not be relied upon as the definitive method in the diagnosis of ebsteins anomaly
MED	3326 unusual aneurysm of the membranous interventricular septum the case of a patient with a huge aneurysm of the membranous interventricular septum is presented this is believed to be the first such patient to have undergone successful resection
MED	934 laevocardia with situs inversus a case report and a review of literature a case of levocardia with inversion of the cham  bers of the heart and transposition of the great vessels and situs inversus has been described gross cyanosis and clubbing were present and were due to a veno arteri  al shunt through a right sided superior vena cava open  ing into the arterial atrium and passage of venous blood into the aorta through a ventricular septal defect the case was complicated with right sided hemiplegia and with the development of a liver abscess a review of the literature with prognosis and possible etiology of the condition has also been made
MED	1831 postoperative aneurysm of the right ventricle twelve patients with postoperative aneurysm of the right ventricular outflow tract after corrective surgery for pulmonic valvar stenosis ventricular septal defect and tetralogy of fallot are reported the literature is reviewed and the pathogenesis is discussed different diagnostic tests are evaluated stressing the role of roentgen examinations and the importance of careful follow up by intercalative chest roent  genography
MED	1991 ventricular septal defect with aortic regurgitation medical and pathologic aspects thirty four patients with ventricular septal defect and aortic regurgitation repre  senting less than 5 of the patients with ventricular septal defect are discussed a loud systolic murmur characteristic of ventricular septal defect is noted dur  ing infancy whereas evidences of aortic regurgitation protodiastolic murmur and wide pulse pressure does not usually appear until some time between 2 and 10 years of age clinical and catheterization data indicate that the principal hemody  namic load is aortic regurgitation whereas the ventricular septal defect does not usually result in a large pulmonary blood flow or high pulmonary arterial pressure in about 50 of the patients a significant pressure gradient across the right ven  tricular outflow tract exists detailed pathologic studies indicate that the ventricular septal defects are high and anterior and encroach to a greater or lesser degree on the membranous bulbar septum the right coronary cusp is the one most severely involved and by its prolapse causes aortic regurgitation the noncoronary cusp is always less severely affected the anatomic basis of the pressure gradient ob  served across the right ventricular outflow tract is not always clear
MED	2431 the natural history of arrhythmias following septal defect reapir the repair of 191 atrial and ventricular septal defects between 1955 and 1961 was reviewed to determine the incidence and prognosis of arrhythmias related to operation cases included 90 ventricular septal defects 61 atrial defects of the ostium secundum type and 40 of the ostium primum variety nodal rhythms second degree blocks complete heart block and flutter or fibrillation that persisted after completion of operation were analyzed while intermittent ectopic beats sinus tachycardia and bundle branch blocks were excluded fifteen per cent of the patients with ventricular defects 17 with ostium primum defects and 35 with ostium secundum defects developed abnormal rhythms associated with repair of 18 patients whose arrhythmias began during operation there were 8 deaths no fatalities occurred in the 24 patients who developed arrhythmias in the postoperative period seven deaths were associated with complete heart block and one with second degree block although only one half of the patients who developed arrhythmias had pulmonary artery pressure greater than 30 mm hg systolic all fatalities occurred in this group four of the deaths followed surgery with the use of the pump oxygenator in children under 30 months of age thirty eight per cent of the abnormal rhythms that began in the postoperative period were nodal flutter and fibrillation were common following repair of atrial secundum defects in patients over 15 yr of age but did not occur in younger patients deaths from heart block occurred in the first 30 days following operation except one 5 months later survivors of complete heart block reverted to a less serious arrhythmia or normal rhythm within 3 months
MED	1021 left ventricular angiocardiography in the study of ventricular septal defects sixty five cases of ventricular septal defect were studied by left angiocardiography the left ventricle was entered by retrograde arterial catheterization with a catheter having a j shaped tip this procedure appears to be little or no more hazardous than right sided angiocardiography ventricular septal defects may be divided into 5 types depending on their location in the ventricular septum the anatomic and radiological features of the septum and septal defects are described selective in  jection of contrast material into the left ventricle opacifies the blood passing through the defect in the septum and permits preoperative localization of the defect in rela  tion to identifiable anatomic landmarks multiple defects of the septum are well de  monstrated such information may be of considerable value to the surgeon under  taking repair of the septum left ventriculography often combined with supraval  vular aortography has been used when indicated to differentiate between mitral insufficiency and ventricular septal defect and in the detection of other cardiac ano  malies whose manifestations are marked by those of the septal lesion this tech  nique is well suited to the postoperative study of patients following repair of the septal defect and for follow up studies in patients not operated upon to clarify the natural history of defects in different portions of the ventricular septum
MED	4105 free fatty acid metabolism in chinese hamsters in normal chinese hamsters cricetulus griseus the mean concentration of free fatty acids ffa in serum varied from group to group but was 1 consistently 4 to 9 times greater than in rats dogs or man 2 slightly higher than in syrian hamsters 3 two  to four fold higher than in fasting or alloxan diabetic rats the epididymal adipose tissue of the chinese hamster 1 had initial concentrations of ffa comparable to those in the rat and syrian hamster 2 released in the same time interval 8  to 10 fold more ffa in vitro than this tissue of the rat 3 had higher concentrations of ffa after incubation than the incubated tissue of the rat the retroperitoneal perirenal adipose tissue of the chinese hamster was less ac  tive in release of fatty acids in vitro than the epididymal but was however more active than the epididymal adipose tissue of the rat these characteristics of ffa metabolism in the chinese hamster were apparently attributable to species not to age diet or sex in the chinese hamster the weight of the epididymal adipose tis  sue per gram of body was relatively high it appears that in this species the rate of release of fatty acids from adipose tissue is great leading to high ffa concentra  tions in serum in chinese hamster and rat adipose tissues in vitro glucose and in  sulin separately reduced the rate of release of ffa and the amount of ffa in the tissues but glucose and insulin together produced the greatest reduction the net reduction in ffa release by glucose and insulin in vitro was greater in tissue from the chinese hamster insulin markedly increased glucose uptake by the adipose tis  sues of both species the possible relation of the results to spontaneous diabetes in the chinese hamster is discussed
MED	95 changes in serum non esterified fatty acid levels in spon  taneous and in oxytocin induced labour the nonesterified fatty acid nefa concentration of serum rises progressively during the course of normal labor the rise appears to be related to the duration of labor the use of oxytocin to induce and stimulate labor does not alter the normal pattern of rise in nefa provided it is given in physiologic dosage the levels of nefa in the umbilical vein and the umbilical artery at delivery are comparable and always significantly lower than the maternal level the maternal fetal ratio varies between 1 7 1 and 3 9 1 in this series following delivery the nefa levels begin to fall almost immediately the rate of fall is 10 30 of the delivery value in the 1st hour 30 50 within 18 hr and 50 70 within 36 hr
MED	1545 the effect of combined glucose and insulin infusions on the lipoid and carbohydrate metabolism of the parturient woman and of the fetus the infusion of glucose with insulin during delivery was used by the authors pri  marily in order to determine whether the utilization of glucose can be enhanced under these conditions they wanted to investigate whether the increase of unesteri  fied fatty acids in the cord blood which takes place after a sole glucose infusion in the mother could be caused by the low capability of glucose utilization in the fetus the infusion during delivery which consisted of the application of 500 ml of 10 glucose and 16 u of insulin over a period of 30 min brought about a greater decrease of unesterified fatty acids in the parturient woman as compared with the infusion of glucose exclusively the reason for this result is thought to be due to a better utili  zation of glucose which is favorably influenced by insulin during the infusion of glucose with insulin an increase in the values of lactic and pyruvic acid took place in the parturient women this was probably due to an accelerated glycolysis and an increased production of lactic acid but not caused by a higher share of the anaerobic metabolism in the cord blood there were likewise increased values of lactic and py  ruvic acid as a reflection of the higher values of these substances in the mother the formation of these products of metabolic breakdown by the fetus however was not significantly increased after infusion of glucose with insulin the other investigated parameter values including those of the levels of unesterified fatty acids are found in the cord blood in similar amounts as after infusion of glucose alone these re  sults cannot reliably prove the passage of insulin through the placenta especially after a continued study of the metabolic values in newborns as a proof of the passage of insulin through the placenta could not be established it is possible that after an intake of insulin the increase of unesterified fatty acids in the cord blood could be caused by a relative insufficiency of the insular apparatus of the fetus the most probable reason for the increase of unesterified fatty acids is the different depo  sition and metabolization of unesterified fatty acids in the course of intrauterine life
MED	1547 glucose and nonesterified fatty acid levels in maternal and cord plasma the authors established in 44 healthy women at the moment of delivery the contents of glucose and free fatty acids in the blood of the mother and of the umbilical cord the concentration of both substances was significantly higher in the mother than in the infant the relation for free fatty acids was 1 7 1 that for glucose 1 3 1 the relation glucose fatty acids in the mother was significantly different from that in the infant
MED	3294 epinephrine infusions in normal and toxemic pregnancies ii plasma glucose nonesterified fatty acid and epineph  rine norepinephrine alterations seven controls and 9 preeclamptic patients were infused with different amounts of epinephrine plasma nefa glucose and catecholamines were determined before during and after epinephrine infusion the toxemic patient responds to the metabolic effects of infused epinephrine in a manner similar to that of the normal pregnant patient the increased levels of nefa in pregnant patients are explained by a com  plicated biochemical mechanism involving an increased availability of cortisone like steroids slightly increased amounts of thyroid hormones etc resulting in an alteration of carbohydrate utilization the study leads to the conclusion that epi  nephrine is not an etiologic agent in toxemia of pregnancy
MED	766 a lipid mobilizing substance in the serum of pregnant wo  men of probable placental origin a substance capable of inducing free fatty acid ffa release was found in the sera of 12 from 13 pregnant women the rat epididymal fat pad was used for bioassay this substance circulates in late pregnancy and disappears within 5 days post partum it is present in crude placental extracts and is removed by their deproteination it is nondialyzable application of pituitary extraction procedure to placentae yielded active fractions where pituitary growth hormone is usually found in accordance with these facts a hypothesis concerning a part of metabolic changes occurring during preg  nancy was pronounced as follows the described substance diminishes maternal glu  cose consumption through the elevation of plasma free fatty acids or by direct in  hibition of glucose uptake or both this permits a preferential shunting of glucose to the fetus at the same time increased plasma free fatty acid levels would serve as the alternative maternal energy substrate elevated maternal insulin levels during late pregnancy stabilize the degree of maternal lipid mobilization the contrainsulin properties of a substance capable of mobilizing free fatty acids and inhibiting mater  nal glucose utilization would pose a diabetogenic challenge and in the face of com  promised maternal insulin reserves provoke overt or worsen existing diabetes mellitus
MED	3682 metabolism of free fatty acids during perinatal life of lambs there is a rapid rise of free fatty acids in blood plasma after birth in newborn lambs this study confirms this rise caused by an augmented mobilization of these acids from the tissues norepinephrine easily mobilizes free fatty acids in adult ewes in newborn lambs this special effect is lacking though cardiovascular re  sponses are clearly demonstrable blocking the sympathetic nervous system in newborn lambs inhibits the rapid rise of free fatty acids after birth this is com  patible with the concept that increased activity of these sympathetic nerves after birth is an important factor for free fatty acids mobilization during intrauterine life there is an ample study of carbohydrates and the organism uses them as an energy source hypoglycaemia resulting from sudden carbohydrate deprivation at birth demonstrates with rising free fatty acids the change over to tissue fat as main source of energy
MED	1163 the effect of glucose infusions on the lipoid and the carbohydrate metabolism of the parturient woman and the fetus in 20 parturient women who were given glucose infusions during the expulsive stage of labor the authors were able to observe an unusual hyperglycemia and a decrease in unesterified fatty acids uefa the uefa level usually increases regularly during delivery likewise the values of esterified fatty acids efa showed an in  crease above the normally present levels in women who had received a glucose in  fusion during the expulsive stage of labor the results show that during delivery both hyperglycemia and the increase in lipoids are predominantly due to the energy demands of the organism however there is also evidence that other hitherto un  known factors may play a role in the fetus the infusion of glucose leads to an in  creased glucose retention the infusion however does not bring about a decrease but contrary to the expectations an increase in the uefa values in general such a reaction is not found in any of the subsequent periods of life further inves  tigations were conducted in order to find an explanation for the paradox uefa  reaction as shown by an analysis of the lactic acid and the pyruvic acid values the increase in the uefa can most probably not be attributed to an impairment in the fetal metabolic conditions the administration of physiological saline infusions to 10 parturient women under equal conditions revealed that the cause for the uefa  increase can apparently neither be found in hemodynamic changes due to the infusion nor in changes of the electrolyte balance but rather in an adaptation insufficiency of the fetal islet cells respectively in a different fat mobilization or fat deposition
MED	1320 the plasma free fatty acid composition and blood glucose of normal and diabetic pregnant women and of their new  borns the blood glucose and plasma ffa content and composition of the newborns of normal women gestational diabetics and insulin dependent diabetics were analyzed normal maternal ffa levels were twice the fetal values by 2 hr of age ffa in  creased 4 fold over initial values in normal infants while infants of gestational diabetics had a 3 fold rise and those of insulin dependent diabetics only 2 fold blood sugar at the same time decreased and there was an inverse relationship be  tween blood glucose in the normal infants and ffa this relationship is altered in the infant of the diabetic mother gas chromatography of plasma indicated a higher ratio of unsaturated to saturated ffa in mothers compared to infants no pattern differences were noted between the normal and diabetic mothers except that the latter had higher oleic acid in the initial 2 hr of life the patterns changed although no differences were noted between infants of diabetic mothers and normals the observations suggest 1 the metabolic interrelationships of glucose and ffa in the normal infant are different from those in the infant of the diabetic mother the latter infant having a state of physiologic hyperinsulinism 2 plasma ffa in the fetus is derived from both fetal fat synthesis as well as placental transfers 3 the infant of the diabetic mother does not differ from the normal as regards ffa com  position
MED	3107 lipids of human placenta the chloroform methanol soluble components of 4 human placentae were isolated by rubber membrane dialysis and gas chromatography and analysed two thirds of the total lipids consisted of phosphatides with lecithin as the main component 22 5 colamine cephalin 13 and sphingomyelin 7 5 free cholesterol form  ed 14 of the total lipids while cholesterol esters accounted for 6 and trigly  cerides for 13 investigation of the phosphatide fatty acids by gas chromatography showed a content of 60 saturated 27 simple unsaturated and 12 polyunsaturated acids the fatty acids of the triglycerides consisted of about 50 saturated and 25 each of simple and polyunsaturated acids the polyenoic acids 30 of the cholesterol fatty acids had a high content of linoleic acid about one quarter that of the total acids
MED	377 experimental study of sensitization to nickel sensitization was effected by epicutaneous application of nickel sulfate in 15 guinea pigs it was confirmed by the appearance of eczematiform lesions in skin tests with nickel sulfate for maintenance of the animals in good general condition it was necessary to add vit c and antiinfective agents to the diet for this reason the allergenicity of the ni salt had to be augmented by the use of adjuvants freunds complete adjuvant or alum such adjuvants act by stimulating the res the method for sensitization of guinea pigs to metal salts having been worked out it is now proposed to study the mechanism of such sensitization the biological disturbances involved and the possible existence of cross sensitizations
MED	2285 some remarks on the nickel dermatitis by non occupational contact this dermatitis represents 2 of the skin diseases observed at the allergologic outpatients department of the dermatological clinic of milan the disorder is more frequent in women and prefers the thighs girdles keys and the wrist watch its incubation period is generally long and a peculiar papulo vesicular follicular and lichenoid eruption often follows
MED	3200 studies on the binding of protein by nickel with special reference to its role in nickel sensitivity the reaction between nickel and proteins was studied using the technique of equilibrium dialysis in most of the experiments crystalline bovine serum albumen was used the nickel protein complex was of low stability the quantity of nickel bound by the protein being dependent on the concentration of free nickel ions the ph and the particular protein used the sites of binding of the nickel ions were primarily carboxyl and amino groups the author concluded that it was unlikely that nickel behaved as a hapten capable of initiating an allergic response
MED	2596 experimental nickel contact sensitization in man in 16 of 172 male prisoners contact type delayed hypersensitivity was induced experimentally by repeated application of 25 nicl2 in a 0 1 sodium lauryl sulphate solution on the skin test reactions with 5 nicl2 with occlusion were found to be irritating no experimentally sensitized subject demonstrated clinical sensitivity to the metal in his environment
MED	1013 hand eczema the clinical aspects of 106 cases of hand eczema are reviewed the clinical types are defined nummular eczema nickel allergy atopic dermatitis hyperkeratotic dermatitis of the palms hand eczema post partum mycotic eczema contact dermatitis occupational eczema and idiopathic eczema the results of the patch tests the influence of psychological and psychiatric factors the effect of water and cleansers the diagnosis treatment and prognosis are discussed in 39 no significant causative factor could be found in many cases where causative factors could be identified these were probably no more than contributory superimposed upon an underlying idiopathic eczema
MED	670 steroid aerosol spray in contact dermatitis prophylactic use with particular reference to nickel hypersensitivity proper use of topical aerosol dexamethasone decadron spray affords complete protection to patients with nickel sensitivity this clinical result is confirmed by the results of patch testing nickel sensitive patients with a 5 nickel sulfate solution and nickel coins a combination of dexamethasone and an isopropylmyristate film is necessary for successful prophylaxis the individual components alone do not protect these patients clinical and patch test results indicate that a moderate degree of protection is afforded to patients with paraphenylenediamine sensitivity patch test results indicate that the spray does not protect against poison ivy and ragweed oleoresin potassium dichromate certain rubber accelerators and monobenzyl ether of hydroquinone it affords a moderate protection against formaldehyde no tests were done with patients with formaldehyde hypersensitivity a fair degree of protection was obtained by the use of the spray in housewives eczema presumably due to irritants present in soap and detergents
MED	2078 the pathogenesis of contact eczema due to detergents for domestic use the thesis is maintained that eczema due to household detergents is pathogenically linked with allergic contact sensitization to metallic salts especially chromium and nickel in a series of 20 cases of contact eczema attributable to detergents the existence of sensitization to these metals was demonstrated by the patch test likewise in the analysis of 9 samples of different detergents used for washing in all of them chromium and nickel were found to be present in a proportion which for either of these metals varied between 1 and 5 p p m
MED	4010 studies of nickel carcinogenesis the subcellular partition of nickel in lung and liver following inhalation of nickel carbonyl wistar rats were exposed by inhalation to nickel carbonyl either once only at a concentration of 80 ppm for 60 minutes 0 60 mg ni co 4 l air or repeatedly at 4 ppm 0 03 mg ni co 4 l air for 30 minutes 3 times weekly for 1 year they were killed 24 hours after the final period of exposure nuclear mitochondrial microsomal and supernatant fractions were isolated from lung and liver homogenates and measurements of the nickel nitrogen and rna content of each subcellular fraction were made the greatest ratios of nickel to nitrogen were in the nuclear fractions of both liver and lung but increased amounts of nickel were also found in the microsomal and supernatant fractions of both liver and lung and in the mitochondrial fraction of lung
MED	188 studies of nickel carcinogenesis metastasizing pulmonary tumors in rats induced by the inhalation of nickel carbonyl in a combined series of studies 6 out of 409 rats n b only 195 survived for more than 3 wk exposed to nickel carbonyl developed pulmonary carcinoma with metastases the lesions included the common types of pulmonary cancer squamous cell carcinoma adenocarcinoma and anaplastic carcinoma all of the pulmonary lesions were found between 24 and 27 mth after the initial exposure to nickel carbonyl the amount of nickel found capable of inducing lung cancer in the rat was comparable to the amount of nickel inhaled by persons smoking less than 15 cigarettes per day for a period of a year the mean weight of rats chronically exposed to nickel carbonyl was found to be consistently less than that of the control rats throughout the entire 3 year period of study
MED	189 influence of age sex and glandular extirpation on muscle carcinogenesis in rats the carcinogenic effect of a single intramuscular injection of nickel sulphide in an aqueous suspension to which penicillin g had been added was compared in male and female castrated hypophysectomized or intact rats of different ages the response seemed most marked in intact females injected when 2 mth old castrated or hypophysectomized 2 month old females were less responsive one month old intact males were more responsive than 2 month or 3 month old intact males 1 month old castrated males or 1 month old intact females more data would be required before firm conclusions could be drawn from these results
MED	3176 studies of trace metal metabolism electron paramagnetic resonance of manganese in ribonucleic acids the electron paramagnetic resonance spectrum pattern of manganese was readily detected in all of the samples of rna the resonance patterns indicate that manganese is present in rna in a divalent state and suggest that manganese is located at the center of a distorted octahedron of oxygen atoms from the intensity of nominally forbidden resonances the crystal field splitting parameter d was estimated to be 0 02 cm  1
MED	4790 metal chelates as potential reactivators of organic phosphate poisoned acetylcholinesterase as part of a study to investigate metal chelates as possible reactivators of phosphate poisoned acetylcholinesterase it is shown that chelates act as inhibitors of the enzyme in addition copper and nickel chelates of 2 pyridinealdoxime catalyze the decomposition of dfp and sarin compared to 2 pam however these chelates are very poor reactivators probably because of an improper alignment of the oxine oxygen in the chelate enzyme complex
MED	3446 effect of nicl2 on an isolated ranvier node an attempt was made to explain the extreme prolongation of the nodal potential by 0 1 1 0 mm nicl2 in terms of the ionic theory the effects of nicl2 at room temperature are similar to those of temperature reduction decreased maximum rate of rise of the action potential lengthened action potential duration elevated threshold increased tendency for repetitive activity in addition the amplitude of the action potential is slightly increased the long lasting plateaus of the responses obtained under the combined influence of nicl2 and temperature reduction are shortened by cathodal polarization strong anodal polarization and decrease of na 0 the plateau can be prematurely terminated by short anodal pulses of critical amplitude short cathodal pulses reduce the duration of the plateau gradually with increasing pulse strength increased k 0 prolongs plateau duration the steep repolarization phase which normally terminates the plateau is replaced by a long lasting after depolarization with stepwise potential decline the amplitude of k depolarization is not influenced by nicl2 or temperature reduction 1 0 mm nicl2 changes the relation between maximum rate of rise and steady state polarization the potential change required for 50 sodium inactivation is 8mv in normal ringers solution and 16mv in the presence of 1 0 mm nicl2 22 c 1 0 mm nicl2 increases the time constant of delayed rectification as measured in na poor solutions at 4 c by a factor of about 2 the decrease of action potential under cathodal polarization is slightly delayed by nicl2 it is concluded that prolongation of the nodal action potential by nicl2 is due to delayed and reduced inactivation of na permeability and delayed increase of k permeability part of the nicl2 effect could be explained by assuming competition between ni and ca for specific sites at the membrane
MED	2302 the carcinogenic activities of n hydroxy 2 acetylaminofluorene and its metal chelates as a function of retention at the injection site the carcinogenic activities of s c administered n hydroxy 2 acetylaminofluorene n hydroxy aaf and a variety of its metal chelates indicate that greater activity locally is associated with a longer retention of the chelates at the site of injection with a slow release of n hydroxy aaf to the surrounding tissue no tumors were obtained at the sites of 4 injections of n hydroxy aaf 3 2 mg injection but 4 and 16 of 20 rats developed sarcomas at the sites of 8 and 16 injections respectively the nickelous cobaltous ferric or cupric chelates induced moderate to high incidences of sarcomas with 1 or 4 injections in these cases one half of the administered n hydroxy aaf was retained at the injection site for 4 50 days the manganous and zinc chelates and the potassium salt were less active at the injection site the half retention times for these ranged from 2 5 hr to 2 5 days the comparable half retention time for n hydroxy aaf was about 2 hr injection of the metal derivatives s c with short half retention times resulted in higher incidences of mammary tumors than injection of the derivatives with half retention times of 4 or more days when administered in the food the cupric chelate of n hydroxy aaf induced the same spectrum of tumors as n hydroxy aaf but the incidences were lower while the prolonged retention of the material at the injection site may account for the greater carcinogenic activities of the metal chelates serious consideration must also be given to the possible importance of chelation of carcinogens or their metabolites to cellular constituents
MED	12083 generation of action potentials in single ranviers nodes of isolated frog nerve fibres under the influence of nickel and cadmium ions russian by experimenting on single ranviers nodes of frog isolated nerve fibres it was shown that along with a marked prolongation of the repolarization phase of the action potential ap ni and cd ions also caused a rise of the critical membrane depolarization level and an increased ap amplitude with somewhat reduced steepness of its ascending phase ni and cd ions restored the ap generation in the nodes of ranvier altered by a 0 01 procaine solution by an excess of potassium ions 00mm 1 of kcl or by slight mechanical injury during dissection it was only with a reduced na concentration in the medium that the restoration of ap could be achieved ni and cd ions considerably slowed down and weakened the cathodal rise of the critical level and the ap reduction cysteine 10  2 to 10  3 m eliminated all the effects of the mentioned ions a suggestion is made that by binding the sh groups of the nerve fibre proteins nickel and cadmium reduce the rate of inactivation and the increase of potassium permeability in depolarization and also weaken the initial inactivation and the increase of potassium permeability in depolarization as well as weaken the initial inactivation of the membrane i h whenever this happened to be raised by previous influences
MED	1287 agnostic alexia and constructive apraxia with regressive evolution in a child of 12 yr of age after an acute encephalopathy the etiology of which could not be determined a boy of 11 yr and 10 mth of age developed a syndrome of agnostic alexia and constructive apraxia which was remarkably pure the intellectual functions were normal as determined by iq tests speech was not disturbed either the child could not read or copy a text but was fully able to write both freely and dictated the patient could not read what he had written this shows the characteristic features of agnostic apraxia motor activity and performance were normal but the child had extreme difficulty in constructing geometric forms even elementary either spontaneously or by copying this remarkable syndrome disappeared and during its involution it was followed up
MED	1288 the symptomatology of the parietal cerebral syndrome of the dominant hemisphere parietal dyslexia and conduction aphasia this is a very comprehensive study on a patient in the beginning there was a pronounced gerstmanns syndrome with autotopagnosia for parts of the face dyspraxia and constructive apraxia and dyslexia the autotopagnosia and mild left right disturbances showed marked regression actual hemianopsia was not observed but tachistoscopy revealed that perception of the right field of vision was poor audiometric examination showed a conduction deafness and disturbed binaural word synthesis the disturbances were examined meticulously and tested for symptom relationships which became evident in the various factors concerned with creative ability
MED	4544 observations on colour agnosia a 56 year old right handed man following the formation of a left posterior subdural hematoma developed spelling dyslexia and impaired picture interpretation which resolved and color agnosia which persisted the latter impaired the use both of color information and of the names of the colors this may be explained as a disorder impairing the recollection and formation of associations between color names and other types of information with resulting interference in any task in which colors or their names have to be placed in a specific context the alternative views of willbrand 1887 that here a limited dysphasia and of sittig 1921 that a recognition defect is simultaneously present cannot be excluded in the present and in previously reported cases the causative lesion seems to have been posteriorly located in the dominant hemisphere in the borderland between the area receiving visual input and the language or verbal recording area
MED	652 bitemporal hemianopia two stages can be distinguished in the development of bitemporal hemianopia in hypophyseal tumors the first stage is the consequence of direct pressure of the tumor on the lower side of the chiasma hence its start with upper quadrantic field defects in this stage the visual disorder is amenable to prompt and complete restoration with progressing growth of the tumor the second stage follows as consequence of constriction by the circle of vessels in this stage nerve fibers are being destroyed therefore after pressure relieving operation no restoration occurs or to a limited extent only
MED	387 ophthalmic manifestations of bilateral non occipital cerebral lesions twelve patients are described with neuro ophthalmic symptoms resulting from bilateral cerebral lesions in areas other than the occipital lobes the symptoms and signs are categorized as follows group i those showing predominant disturbances in visual object recognition visual agnosia and disturbances of visual spatial localization group iia those having defects in voluntary control of eye movements ocular motor apraxia group iib those with persistent palsies of conjugate gaze although these symptoms may be present to some extent with unilateral lesions they are much more profound and less able to be compensated with bilateral lesions the evidence in the present cases suggests a biparieto temporal localization for the lesions causing visual agnosia disturbances of spatial localization and ocular motor apraxia and a more frontal localization for the lesions causing prolonged paralysis of conjugate gaze
MED	1774 the speed of reading basis for a clinical function test as an easily comprehensible measure for the capability of reading the author recommends the determination of the reading speed for supplementation of the ocular function tests the method in question constitutes a senso motor efficiency test which is of value in the appraisal of haemianopias paracentral and central defects of the visual field in squint amblyopias and in spontaneous nystagmus
MED	1303 the problem of visual agnosia this is a critical assessment of the ancient and modern theories on visual agnosia an original description of the subjective world of these patients is also given visual agnosia is a rare disorder but it has led to comprehensive discussions for instance by the fact that the problem of normal visual perception is always involved bays view which denies the existence of agnosia as a separate phenomenon in perception disorders is especially dealt with it is affirmed that no case has been described in the literature in which visual agnosia is decidedly a pure and isolated phenomenon mostly there are also disturbances in the intellectual interpretation of visual data often there is metamorphopsia or asthenopia there is no localized prestriate gnostic center for visual impressions the older concept of higher and lower levels of perception and perception disorders is also criticized visual perception is not a passive but a very active process in which neurophysiological and psychological aspects are involved each of these can be disturbed leading to various degrees of visual perception disturbance
MED	2496 dysbarism among hyperbaric personnel a survey of the effects of hyperbaric exposure on 62 medical personnel exposed to 1 516 compressions and decompressions revealed no case of permanent ill effect pain in the ears or sinuses was the most common symptom but could often be ameliorated or avoided by the valsalva technique of forced insufflation with the nostrils occluded the most serious symptoms encountered were 3 episodes of transient homonymous hemianopsia the classic symptoms of decompression sickness extremity pains the bends pulmonary or substernal distress the chokes and skin dysesthesias occurred only rarely and were so mild or so fleeting as to require no treatment a further reduction in symptoms without increase in decompression time may be obtained by the inhalation of 100 oxygen during decompression stops at pressures below 26 8 pounds per square inch gauge psig
MED	2996 visual static agnosia with special reference to literal agnosic alexia this is a report of 2 right handed adults who had visual agnosia with predominance of literal alexia  recognition of letters was poor or nonexistent when the patient simply viewed the material static method but if the letter was slowly developed for them they were able to identify it dynamic method one patient had vascular pathology which was considered to involve both occipital lobes and the 2nd patient had the surgical removal of the left occipital lobe for an angioma
MED	1388 optic agnosia semeiological and pathogenetic aspects the authors discuss the classical concept of agnosia and make a survey of pathogenetical factors which determine its phenomenology the original and traditional concept of such a term implied the loss of the capacity to recognize objects when the functions of sense organs are undamaged the psychological studies on perception and the modern physiology of vision allow to avoid the dichotomy between sensation and perception and to affirm their identity cortex and recptors are closely bound and function in unison every cortical alteration is thus reflected in sensorial functions it is therefore that on practical semeiological grounds it is possible to obtain a congruous information of the corresponding cortical functionality through an exploration of sense organs carried out by suitable means since we are confronted with functional changes exploration methods must be fit to evaluate dynamic aspects of perception in connection with the temporalization and spatialization of stimuli such methods are now quite numerous and often complex a particular stress is laid on local adaptation flicker fusion and tachistoscopy on account of their significance and suitability by such methods it is possible to show those functional deficits or pathological disturbances of sensorial functions which are also behind the pathology of visual recognition fluctuation extinction alteration in the perception of movement both real and apparent changes in adaptation to light and darkness are all phenomena which can be detected instrumentally and which at the same time may be of determinant importance for the onset of agnosic behaviour the complexity of the latter on the other hand cannot always be explained by sensorial disturbances only other mechanisms with a function complementary but not less indispensable to the dynamics of perceptive processes may intervene and interfere in it on the basis of the latest neurophysiological data the attention is called to ocular motility and proprioceptivity centrifugal innervation of sensorial receptors and vestibular afferences a particular clinico pathogenetical significance is attached by the authors to the association of lateral visual disturbances with altered proprioceptive and kinesthetic information from the corresponding half body such association in fact is nearly always present among the factors responsible for the most strictly spatial errors of agnosic pathology in the light of these pathogenetical considerations as well as of suitable semeiological findings the authors deem it convenient to divide their cases into 3 categories with distinct clinical features a cases in which altered visual behaviour may be related to changes of the visual function and of its complementary mechanisms b cases in which hemianopia is associated with a homolateral deficit of somatic proprioceptivity c cases in which the changes in behaviour are chiefly but not only due to a dissolution of the symbolic sphere
MED	2568 clinical observations on hemianopia japanese the clinical findings in 19 cases of hemianopia were analyzed hemianopia was caused most frequently by vascular lesions of the central nervous mianopsia and by tumors wilbrands prism sign which is generally taken as evidence of an optic tract lesion was positive in one case with a parietal lesion no case showed a cogwheel movement of the eyeball optokinetic nystagmus was positive in 3 cases one of which proved to have a parieto occipital aneurysm the etiological factor could not be identified in the remaining 2 cases macular sparing was found to be symptomatic of an occipital lobe lesion incongruity of the 2 fields was observed in 2 cases with an occipital lobe lesion as for the prognosis hemianoptic field defects remained stationary in cases of vascular lesions on the other hand perfect recovery of the visual field defect occurred in cases with an occipital lobe tumor and in hypophyseal hypertrophy caused by pregnancy the visual acuity of hemianoptic patients was fairly good and no deterioration occurred during the observation period of about 4 years only one patient out of the present series died these results suggest that a favorable vital prognosis can be accorded to hemianoptic subjects
MED	1384 importance of campimetry and carotid and vertebral angiography in thrombosis of the posterior cerebral artery the authors report a case of thrombosis of the posterior cerebral artery which presented only lateral homonymous hemianopia and stress the importance of campimetry and of carotid angiography beside vertebral angiography
MED	375 hemianopsia and glaucoma after a discussion of the bibliographic references to the few observations on the simultaneous occurrence of hemianopsias and glaucoma the author states on the basis of his experiences the following points homonymous hemianopsias occasionally take place in glaucoma although no direct relation can be established between the former and the glaucoma it has to be pointed out however that in other older patients for example in those with retinal detachment neuritis etc who are likewise subjected to repeated and exact perimetry such hemianopsias do not occur or are to be found at a lesser rate than in glaucoma a homonymous hemianopsia has to be taken into consideration also in the event of a sudden impairment of the visual field in a glaucomatous patient or when the hemianopic defect supervenes in addition to the visual field defect due to glaucoma in cases of binasal hemianopsia the simultaneous presence of glaucoma is not a rare incident whether the binasal hemianopsia is the result of the gradual development of a glaucomatous visual field with nasal defects or whether it constitutes an independent symptom to a certain extent cannot always be clarified in the individual case obviously the condition of the basal cerebral vessels plays a certain role in the development of glaucoma even if this role cannot be clearly defined as yet in cases of binasal hemianopsia a glaucoma has to be ruled out before radical diagnostic and therapeutic measures are carried out
MED	1131 disorders of oculomotor functions in lesions of the optic pathway at the parieto occipital level and their significance in topical diagnosis paresis of ocular movements to the hemianopic side is described in 9 patients with acute vascular lesions in the parieto occipital region in 7 cases the paresis was of the dissociated type with inability to follow the moving finger while ocular movement in a verbally stated direction was quite normal in the remaining 2 patients in whom the oedema extended into the frontal region there was complete paresis of all conjugate movements conjugate paresis receded hand in hand with the parietal symptomatology even if the hemianopia persisted the oculomotor disorders referred to have never been observed in lesions which did not extend beyond the occipital region conjugate paresis has in all cases drawn attention to the presence of hemianopia unobserved by the patients and this has led to a more accurate topical diagnosis
MED	2333 binocularity in anomalous retinal correspondence patients with anomalous retinal correspondence demonstrate complete bitemporal or binasal hemianopia when tested for binocular vision exotropes have a binasal suppression and esotropes a bitemporal suppression this is contrary to the prevailing concept of the function of the peripheral retina in anomalous retinal correspondence 6 references
MED	2120 thioguanine in the treatment of certain autoimmune immunologic and related diseases the therapeutic effectiveness of 6 thioguanine has been evaluated over the past 3 years in 19 patients with diverse syndromes only patients with severe debilitating disease unresponsive to conventional therapy were treated remissions occurred in 2 of 5 patients with systemic lupus erythematosus in 1 patient each with dermatomyositis and necrotizing angiitis 2 patients with psoriasis and 2 of 4 patients with atopic disease improvement occurred in other patients with these diseases and in 2 of 4 patients with neurodermatitis two patients with scleroderma experienced only equivocal benefit significant toxicity attributable to the drug was observed in 5 patients assessment of the eventual value of these agents in therapy requires further study hypotheses regarding the mechanism of action of these agents and the significance of clinical response are discussed
MED	2469 the nature of collagen disease particularly of systemic lupus erythematosus sle with special reference to renal lesions japanese from the results of examination of 161 autopsy cases of collagen diseases rheumatic fever and polyarteritis nodosa pn are considered as diseases of hyperergic nature showing pronounced specific manifestation in particular organs as the reactivity becomes lower this specific localization becomes less significant and many organs become affected in sle it may accordingly be supposed that sle is not a disease of hypersensitivity but one occurring in a state of exhaustion of reactability after prolonged sensitization moreover a sle like syndrome arises not only in the end stage of parasepsis nephritis nephrosis and some cases of prolonged sensitization by myco tb but also in pn pss dm and rheumatism it may therefore be conceivable that sle is a syndrome rather than a separate entity it is most important to consider whether sle like symptomatology may be regarded as a process equal to an auto immunization and whether the key to morphological elucidation of the auto immune phenomenon may lie hidden in this problem
MED	420 therapy of lupus nephropathies by 6 mercaptopurine corticosteroid therapy improved the general prognosis of sle but has no detectable effect on the nephropathy and this is actually the main cause of death a new therapeutic method is presented using 6 mp purinethol leupurin which produced 2 remissions in 6 consecutive cases total and in 4 cases with severe nephropathy definite remission it should be emphasized that 5 of the cases reported had definite npn elevation accordingly they are considered hopeless
MED	2475 lupus erythematosus with fatal hemorrhage into the liver and lesions resembling those of periarteritis nodosa and malignant hypertension immunocytochemical observations a firmly established case of lupus erythematosus with histologic characteristics of periarteritis nodosa and fatal hemorrhage is presented immunocytochemical studies were done to explore the possibility of the vascular lesions being immunological in type by immuno fluorescent techniques y globulin human serum complement albumin and fibrinogen were demonstrated in the vascular lesions y globulin in the renal glomeruli was associated only with complement the conclusion is that lupus erythematosus is primarily an immunological disease with complex auto immune mechanisms operative
MED	198 early experiences with azathioprine in ulcerative colitis a note of caution azathioprine was administered to 10 patients with ulcerative colitis classified as very severe in 2 moderately severe in 7 and relatively mild in 1 patient in conjunction with standard therapy and adrenal corticosteroids in 8 of the 10 patients the possible beneficial therapeutic effects of azathioprine in this small series cannot be evaluated definitively because of the concurrent medication and the preliminary uncontrolled observations however clinical improvement was apparent in 8 of the 10 patients and in 2 patients the favorable course occurred in the absence of steroid therapy in 2 additional patients the favorable course was maintained during the administration of azathioprine following the discontinuance of prolonged steroid therapy in 1 patient the administration of azathioprine was associated with amelioration of an arthritis and pyoderma gangrenosum which did not respond to the use of steroids and other medication immuno suppressive observations were limited the established delayed hypersensitivity response as reflected in various skin tests was unchanged during the administration of azathioprine azathioprine had no discernible toxic effects upon the kidneys or the liver in 2 patients 1 with postnecrotic cirrhosis and the other with serum hepatitis gastro intestinal symptoms anorexia epigastric discomfort and nausea occurred in 8 patients mild to moderate leukopenia developed in 8 patients and in 2 individuals was accompanied by thrombocytopenia temporary alopecia occurred in 1 woman the hematopoietic effects developed within 2 or 3 wk of therapy with azathioprine at a dosage level of 4 6 mg kg day azathioprine does not exert the rapid beneficial effect in ulcerative colitis noted with corticotropin and adrenal corticosteroids therefore its use in severe ulcerative colitis requiring intensive therapy probably is undesirable azathioprine on the basis of these initial observations may be considered for moderately severe ulcerative colitis under circumstances permitting controlled and prolonged therapeutic trial as adjunct medication but with careful supervision for prevention of toxicity especially leukopenia
MED	1281 effect of fluoropyrimidines on delayed cutaneous hypersensitivity the ability to express delayed cutaneous hypersensitivity was assessed in 51 patients with carcinoma evidence is presented that 5 fluorouracil and 5 fluoro 2 deoxyuridine paradoxically potentiate this parameter of immune responsiveness
MED	248 data on etiology pathogenesis treatment results and survival period in 560 patients with cirrhosis of the liver statistics were compiled from a total of 560 cases chosen at random of cirrhosis of the liver the figures refer to the age and sex of the patients as well as to the etiology and the hepatic morphology as the date of death of 304 of the subjects was known it was possible to calculate the survival time after the diagnosis was made only 36 survived the time of diagnosis by 1 year 16 by 3 years and 8 by 5 years these figures show that modern therapy of liver cirrhosis has up to now not succeeded to prolong the life of the majority of the victims in many cases however it is possible to a large extent to relieve the patients suffering by improving the appetite and the general condition and by eliminating ascites and periods of hemorrhage and stupor particular attention should be paid to the prophylaxis of the disease and by studying the survival time assessments and therapeutic reports to the method of selection of the subjects
MED	897 chronic renal diseases and pregnancy a review a review is given of the reciprocal relationships between chronic renal disease and pregnancy after a short review of the most important changes in renal function due to normal pregnancy the diagnosis of chronic renal disease is discussed subsequently the following complications of pregnancy are discussed individually chronic pyelonephritis chronic glomerulonephritis lupus erythematosus the nephrotic syndrome diabetic nephropathy and polycystic disease of the kidney the paper is concluded by a discussion on the influence of pregnancy on the different renal affections
MED	4193 the occurrence to cytomegalovirus infections in childhood leukemia report of three cases cytomegalic inclusion disease cmid presented the following clinical findings in three children with acute leukemia persistent high temperature cough vomiting diarrhea hepatosplenomegaly rales and terminal icterus pancytopenia was present in all including two children in leukemic remission roentgenographic evidence of pneumonia did not appear until the third week after the onset of symptoms abnormalities in liver function tests were late findings intranuclear inclusions were seen in urine sediments of two patients in neither of these patients were intranuclear inclusions demonstrable in the sputa virus culture from urine was done in one of these patients and cytopathogenic changes characteristic of cytomegalovirus cmv were demonstrated cmid was the cause of death in these three children all of whom had received chemotherapy with agents known to have immunosuppressive properties
MED	on chorea lupus erythematosus and cerebral arteritis a woman aged 33 developed chorea 10 yr after the onset of systemic lupus erythematosus sle she had experienced an asymptomatic interval of 8 yr the abnormal movements persisted for 5 mth but then subsided after short term administration of 6 mercaptopurine there are 11 previous descriptions of chorea patients with sle in 3 out of 4 autopsied cases extensive cerebral lesions due to diffuse arteritis were found the cns changes were quite similar to those found in chorea minor
MED	1878 pharmacologic actions on cellular immunity the following chapters of interest in the field of drugs and immunity processes are included manifestations of cellular immunity states of reduced immunologic reactivity present status of pharmacologic immunosuppression tests for susceptibility of tuberculin reactions to pharmacologic action tests for susceptibility of transplantation immunity to pharmacologic action comparative susceptibilities of tuberculin and skin homotransplantation reactions to pharmacologic action
MED	2625 chromosome aberrations in human cells following treatment with imuran five women with various collagen diseases were studied bone marrow aspirates were obtained from each patient before and 12 to 24 days after start of imuran azothioprine therapy fifty metaphases from each sample were counted in patients nos 1 and 2 the increase in cells with structural abnormalities during therapy is significant the aberrations found were mostly breaks of the chromatid and chromosomal type a few abnormal chromosomes were seen among which a ring chromosome in patient no 1 chromatid exchanges were seen in three cells
MED	3645 autoimmune hepatitis in 30 of 301 patients with cirrhosis the cause was uncertain of these 90 cases the clinical picture of active chronic hepatitis could be recognized in 69 and 26 of these were characterized as lupoid hepatitis the relationship between active chronic hepatitis lupoid hepatitis and sle was studied in 3 groups of 25 cases each a comparison was then made between the possible etiological factors the systemic manifestations the survival rate the histological appearances the biochemical tests the autoimmune reactions and the results of the immunosuppressive drugs from this study a concept emerged according to which a proportion of cases of cirrhosis occurring in adequately nourished individuals can be attributed to the end result of an autoimmune reaction
MED	766 a comparison of the effects of selected cytotoxic agents on the primary agglutinin response in rats injected with sheep erythrocytes a comparative study was made of the effects of several cytotoxic agents given at maximally tolerable doses on the primary agglutinin response in rats immunized with sheep erythrocytes given intraperitoneally antigen was given before at the beginning or in the middle of a 5 day course of drug treatment chlormethine mechlorethamine 5 fluorouracil and 5 fluoro 2 deoxyuridine did not suppress the primary response significantly methotrexate 6 mercaptopurine 6 mercaptopurine roboside and 2 amino 6  1 methyl 4 nitro 5 imidazolyl thio purine prolonged induction time and suppressed peak titer maximally when immunization was performed one to three days prior to drug treatment vinblastine did not affect peak titer but did prolong induction time when antigen was given 2 days prior to drug treatment cyclophosphamide markedly prolonged induction time and suppressed peak titer irrespective of the time of antigen administration the antimetabolites appeared to suppress maximally the intermediate stage of the primary response cyclophosphamide appeared to suppress all stages
MED	1959 analysis of mechanism of immunosuppressive drugs in renal homotransplantation dammin g j a long term study of the mechanism of action of immunosuppressive drugs has been completed in bilaterally nephrectomized dogs with kidney homotransplants over 1 000 test animals with 24 different drug protocols have been analyzed increasing numbers of long surviving animals have posed many questions regarding the status treated host the current drug protocol of azathioprine and diazoacetylserine azaserine has produced 90 50 day survivors and 50 100 day survivors the following observations have been documented all animals on prolonged drug therapy are immunologically competent drug therapy can be stopped successfully in some but not all animals long surviving kidneys apparently are protected in some way in the new environment because a second donor kidney can be rejected while the first survives retransplantation of a long surviving kidney back to its original host did not lead to a decrease in renal function long surviving kidneys successfully retransplanted back to their original donors are rejected when transplanted to third party non drug treated recipients immune paralysis does not account for the prolonged survival because the second donor kidney which constitutes a double dose of antigen is rejected while the first continues to survive absorption or metabolism of the drug does not account for the variation in results because two kidneys each from separate donors can be rejected differentially in the same drug treated host and all hosts are sensitized against the recipient and this sensitization continues even in those animals successfully weaned from drugs additional analyses of the relationship of skin homografts and kidney homografts reveal the following skin homografts are universally rejected within 20 days by hosts treated with the drug regimen which protects kidney homografts sometimes permanently when skin and kidney homografts from the same donor are placed simultaneously skin survival is prolonged while kidney survival is shortened this paradoxical effect probably is explained by the production of antibodies by skin which are absorbed by the rejecting kidney additional observations indicate that drug treated animals male and female are fertile and that multiple rejection processes can produce generalized immunological picture in the host similar to an autoimmune disease process
MED	3083 myocardial toxicity of contrast agents used in angiography the myocardial toxicity of many current and some experimental contrast agents has been studied in dogs by use of a previously unreported method of occlusion retrograde coronary venography as well as the familiar technique of selective coronary arterial catheterization the following conclusions appear justified in the light of the experiments not only the iodine containing radicals with which the contrast agents are so often identified acetrizoates diatrizoates iothalamates etc but also the final salification products appear to be responsible for the widely divergent degrees of myocardial toxicity of contrast agents to the point that differ  ent salts of the same compound behave as entirely different agents both chemically and biologically the results seem to indicate the dominance of sodium ion and or the protective effect of methylglucamine salts with respect to the myocardial toxi  city of current radiopaque media reported yet unexplained electrocardiographic changes occurring within one to two seconds from the beginning of massive caval high pressure injections appear to find a causal relationship in the myocardial ir  ritability induced by the distention of the coronary veins and the myocardial infiltra  tion which is intentionally enhanced with our retrograde injection techniques a pe  culiar trait shared in varying degrees by all radiopaque agents tested is their ability to increase coronary blood flow the clinical significance of this phenome  non however remains to be established these studies re emphasize the limita  tions of the standard toxicity studies conducted in animals it should be clear from the results reported that agents to be administered into the coronary circulation demand investigation in regard to their potential toxicity by the methods described herein or variations thereof in fact similar tests should be carried out for all or  gans to be subjected to radiographic examination via the vascular bed the authors hope that this presentation will stimulate renewed investigation particularly in view of the growing clinical applications of selective cardiovascular opacification tech  niques
MED	2476 studies on cardiac dimensions in intact unanesthetized man i description of techniques and their validation ii effects of respiration iii effects of muscular exercise a method is described which permits measurement of relative changes in the exter  nal dimensions of individual cardiac chambers throughout the cardiac cycle in intact unanaesthetized man it consists of suturing multiple radiopaque silver tantalum clips to the surface of the heart at the time of cardiac operations in the postopera  tive period cineradiograms are obtained and the distances between clips are mea  sured on each individual frame this technique has been found to be safe and has been employed in 68 patients without any complications as a result of studies in 8 patients utilizing biplane serial exposures the effects of rotation of the heart in the sagittal plane during the cardiac and respiratory cycles were determined precisely if clips were properly placed on the heart the possible errors resulting from such rotation were found to be quite small during inspiration right ventricular dimen  sions increased while the opposite occurred during expiration and during the val  salva manoeuvre left ventricular dimensions exhibited little change during normal respiration during deep slow inspiration the changes in dimensions of the left ventricle lagged behind those of the right ventricle by 1 to 5 generally 2 or 3 car  diac cycles the magnitude of the changes in the dimensions of the left ventricle was smaller than that which occurred in the right ventricle the effects on ventricular dimensions of light muscular exercise performed in the supine position were studied in 9 patients the end diastolic dimensions decreased by an average of 6 0 of con  trol in the right ventricle and by an average of 5 1 in the left ventricle end sys  tolic dimensions decreased by an average of 5 6 of control in the right ventricle and by an average of 6 5 in the left ventricle these decreases are considered to approximate one half of the resting stroke volume in the 4 patients in whom the rate of right ventricular pressure rise was determined continuously exercise re  sulted in an elevation of dp dt while ventricular end diastolic dimensions decreased these data are interpreted to indicate that an increase in myocardial contractility occurs during muscular exercise in man
MED	3765 radioactive isotope determination of myocardial blood flow by surface counting and ratio formula wilkinson d the results presented here have a large scale error and a large scatter so that the authors recommend that further clinical use of this method should not be at  tempted if the coronary portion of the flow rate curve exists then a change in the present instrumentation is needed to allow use of the technique of sevelius and johnson in defining a coronary portion of the flow rate an attempt is made to evaluate the possible source of errors
MED	1379 risa ventriculography and risa cisternography some general experience of the authors with risa ventriculography and risa cis  ternography is related they conclude that the former technique may be particularly useful in detecting intraventricular tumors and internal hydrocephalus as well as assessing the efficiency of surgical shunts the latter technique may be useful in the study of normal csf circulation as well as in cases of csf leaks arachnoiditis and external hydrocephalus
MED	3485 measurement of the cardiac output and ventricular volumes by radiocardiography cardiac output was measured by external counting after injection of radioisotopes rihsa and erythrocytes cr51 the results in 113 subjects including 16 normals are presented and compared with the results by other methods cardiac output at rest and after exercise was compared in 65 subjects the principle of ventricular volume measurement by radioisotope cardiography is discussed the results of measurement of the ventricular volume in 17 normal subjects and 90 patients and of measurement of the ventricular volume in 57 patients are presented
MED	3762 aberrant left coronary artery five cases of aberrant coronary artery are presented with emphasis on the angio  graphic features and differentiation from endocardial fibroelastosis clinical and electrocardiographic features may suggest the proper diagnosis but only angio  graphy can conclusively demonstrate the continuity between the pulmonary artery and the left coronary artery in these cases blood flow was from the pulmonary artery to the coronary artery forward in 2 cases and from the coronary artery to the pulmonary artery retrograde in the other 3 when the diagnosis of aberrant coronary artery is suspected selective left sided angiocardiography should be the angiographic procedure of choice the differentiation from endocardial fibroelas  tosis and other myocardiopathies is usually not a problem with such a study but may be more difficult with intravenous angiocardiography with this latter type of study the coronary arteries are not generally visible but a persistently thin la  teral aspect of the left ventricular wall should suggest the proper diagnosis sub  sequent confirmation by a left sided injection is advisable
MED	4159 detection of heart shunts by means of i 125 external scintillation detection of a pure dilution curve originating in the right ven  tricle has been pursued by investigators for many yr the use of the soft photons of 125 i offers an improved method of determination by allowing excellent collimation through 2 mechanisms 1 a small half value layer of 2 cm in tissue and 2 uni  directionality in part due to all or none photoelectric absorption of these photons as compared with the pluridirectionality due to compton scatter in the case of 131 i in 30 normal individuals externally detected dilution curves from the right heart ventricle and arterial dilution curves obtained by arterial puncture are compared five hundred microcuries of 125 i are injected into an antecubital vein the amount of radiation absorbed from a 500 uc dose in an adult of 70 kilos is 1000 to 2000 mrads when injected in the form of 125 i iodide the use of 125 i orthoiodohippu  rate is advised due to its short biological half period and the integrated whole body radiation exposure is decreased 100 fold in comparison with the 125 i iodide the shape of the right heart curve is very similar to the arterial dilution curve with a 13 5 excess of counts originating outside the right ventricle area the descending segment of the right ventricle curve has a minimum count rate of only 12 2 of the peak of the curve as compared with the arterial curve of 10 2 5 a mean t 1 2 of the descending down slope of the right ventricle is 1 52 0 45 sec for the right heart curve and 2 4 0 65 sec for the arterial curve the clinical usefulness of this procedure in 20 patients with atrial septal defects and 9 patients with ventricular sep  tal defects is analyzed it seems possible to perform selective right heart radiocardio  graphy by means of external precordial detection of 125 i the method is simple and reproducible
MED	4160 clinical applications of quantitative radiocardiography i results in normal subjects and changes with age a technique is described for routine determinations at the bedside of blood volume cardiac output and pulmonary blood volume by means of the method of quantitative radiocardiography the instrumentation is simple the technique is easy to perform and causes little trouble to the patients only one injection of about 50 uc of rihsa being needed thirty nine patients aged 17 83 yr free of cardiovascular or re  spiratory disorders were studied the results obtained are in close agreement with previous reports only the cardiac index showed a significant decrease with age while the reduction of blood volume and of pulmonary blood volume was slight a close statistical correlation was found between pbv and sv and was interpreted as a dependence of pbv on sv
MED	2725 demonstration of myocardial infarction by photoscans of the heart in man intravenously injected radioiodinated oleic acid was incorporated into heart muscle in sufficient concentration to permit recording photoscans of the heart in man in 3 fatal cases of massive septal myocardial infarction injection of the radioiodin  ated fatty acid rifa was made during life at necropsy photoscans of the excised heart showed a discrete area of absent radioactivity corresponding to the infarcted interventricular septum photoscans of the heart were made during life in 42 pa  tients 9 of whom had suffered recent myocardial infarction there were definite areas of deceased radioactivity corresponding to the location of the infarction judged by the electrocardiogram in 4 and probable areas of decreased radioactivity in 2 of the 9 cases of myocardial infarction the technic as presently employed just approaches the limits of definition of infarction in acute cases modification of the biochemical principles or further development of the y camera may bring the method to a level of diagnostic usefulness
MED	2716 y angiocardiography recordings were made simultaneously with the y cardiogram of a pulmonary an  giogram by means of a collimator placed in the left scapular region and of carotid angiogram by a collimator centered on the axis of the external auditory canal the 3 curves yielded very interesting information on the chronology of the various car  diac cycles the pattern of the pulmonary and carotid y angiograms was valuable in several pathologic conditions it is more logical to measure the cardiac output on the carotid curve than on the y cardiogram especially if there are shunts the pulmonary curve allows rectification of the time constant of emptying of the left cavities of the heart as regards chronologic information on cardiac cycles atten  tion is drawn to the fact that in the pulmonary circulation long and short circuits can be demonstrated the characteristic times can be measured between the time that the radioactive material appears in the left cavities and the time that it leaves the carotid there is an interval of 3 4 systoles which represents the time neces  sary for left circular filling the validity of calculation of the cardiac output with the stewart hamilton formula is discussed this is valid if the collimator covers a small volume of the principal channel it remains to be shown if such a calculation is valid for larger cavities or for 2 cavities through which the radioactive material passes successively and which have different c t functions as well as for all tissue seen by the collimator some of which are not yet irrigated with the radioactive blood while in other areas recirculation has already started these aspects and their application to the pulmonary angiogram are discussed in detail with the authors technique y angiogram is especially valuable as correc  tion for the time constant of the decrease of the left peak is based on the lengthening of this curve this again serves as a basis for determining the left ventricular volume
MED	2717 the value of quantitative radiocardiography in the study of hemodynamics six normal subjects and 7 patients with mitral stenosis were studied quantitative radiocardiographic investigations rihsa were performed according to donatos method the stroke volume as well as the cardiac output were found to be decreased in mitral stenosis the right ventricular evacuation ratio diminished and the pul  monary circulation time prolonged the results pertaining to diastolic right ventricu  lar capacity right ventricular resting blood volume and pulmonary blood volume proved inconclusive
MED	3056 the localization of aortic shunts developed by a precordial registration of i 131 injected into the aorta at different levels a technique for localizing shunts of aortic origin is described based on the analysis of precordial records of i 131 injected at different aortic levels seven patients with patent ductus arteriosus pda 1 with a coronary av fistula 2 with ventricular septal defect vsd 1 with atrial septal defect asd 3 with mitral regurgitation 2 with aortic regurgitation and 2 with systemic hypertension were studied retro  grade arterial catheterization by seldingers technique was performed in all the patients as well as right sided catheterization in those with congenital cardiopathies and transseptal catheterization in those with valvulopathies a dose of 5 15 uc of na i 131 was injected at the levels of the aortic root the ascending aorta the aortic arch the origin of the left subclavian artery ductus level and the descending aorta post  ductus level precordial curves were obtained by means of a 2 inch thallium acti  vated nai crystal focused over the 3rd left intercostal space at the sternal margin the shunt outlet can be detected by obtaining simultaneous venous dilution curves from the right chambers and the pulmonary artery the latter technique was used in 2 patients with pda 1 with coronary av fistula and 1 with vsd these curves were obtained by continuous withdrawal of blood which had flowed through a well scintillation counter the crystal pulses were carried to ratemeters which worked with the following time constants 0 01 0 15 sec for the precordial curves and 0 5 sec for the venous curves a direct recorder with a 5 mm sec paper speed was used normal precordial curves after injecting above the aortic valve were obtained in patients with arterial hypertension mitral regurgitation and asd and vsd a swift downslope which fell down near the baseline level and the recirculatory area was observed
MED	1671 the use of 99m tc pertechnetate in cardiac scanning technetium 99m pertechnetate has been utilized in the aas laboratory for scanning the cardiac blood pool the delineation of the heart pool and surrounding vasculature is comparable to that obtained with the standard 131 i compounds now in use in the authors hands 99m tc had the following advantages since they routinely utilized 99m tc for brain and thyroid scans it is available eliminating the purchase and shelf decay of other materials three to 5 mc quantities may be administered with relatively low patient radiation dosage the associated high count rate permits rapid scanning the identification of pericardial effusions is enhanced by the radio  activity in the stomach which in some cases becomes abnormally separated from the cardiac blood pool
MED	2012 the use of technetium 99m as a clinical tracer element the physical properties metabolism and radiation dose of tc 99m are discussed and compared with those of i 123 i 125 i 131 and i 132 it is shown that with tc 99m the highest in vivo counting rates are obtained for a given internal radiation dose so that mea  surements of high statistical accuracy may safely be made the y ray energy is near optimum for scanning and the observation of transients allowing light weight collima  tors to be used while tc 99m tagged albumin is considered superior to risa for ap  plications such as brain scanning placentography and the measurement of cardiac output i 123 if it becomes available will be preferable for thyroid scanning
MED	2626 a study of central arteriovenous shunts by precordial recording of radioalbumin dilution curves precordial dilution curves of 185 patients were studied 56 of them without cardio  vascular disease 48 with central arteriovenous shunts and 45 with various cardiac diseases collimation was not used allowing only minimal quantities of radioactive material 0 5 2 2 uc of i 131 tagged albumin to be utilized the precordial focusing zone was a critical factor in this technique the application of different discrimina  tion factors among them the ratio between the minimal concentration and the latter  an index proposed here   made possible the diagnosis in 46 of the 48 patients with shunts this method was shown to be as sensitive as classical oximetry done during cardiac catheterization the curves in pure valvular stenosis do not show similar changes to the shunts on the other hand these changes are shown in certain val  vular regurgitations this fact becomes the most important limiting factor in the diagnosis of central arteriovenous shunts cardiac failure does not preclude the diagnosis providing one can exclude valvular regurgitation by other means the method is thus in spite of its limitations of extreme value in diagnosing central arteriovenous shunts especially when the results are analyzed together with clinical
MED	information 2724 primary epidermoid cancers of the lung electron micro  scopic study an electron microscopic study was made of 8 squamous cell 3 undifferentiated and 3 alveolar carcinomas of the lung on biopsy specimens embedded in methacryl  ate the squamous cell carcinomas were found to contain cylindrical cells with glycogen granules scanty mitochondria a reticular endoplasm which was chiefly vesicular numerous free ribosomes and bundles of confluent fibrils in the desmo  somes the authors also observed in the center of the tumor nodes cells richer in tonofibrils which enveloped the nucleus and cells in which all the cytoplasmic organelles had almost disappeared except for tonofibrils or cells packed with keratohyalin and even lipid granules sometimes arranged in lamellar formations of the myelin type the picture as a whole was that so often seen in the optic microscope tumor foci formed of slightly differentiated cells at the periphery which became more differentiated as one approaches the center the undifferenti  ated cells resembled more the intermediate bronchial cells than the basal cells the paper does not describe the undifferentiated and alveolar carcinomas
MED	1375 loss of neoplastic properties in vitro ii observations on kb sublines ten sublines of the kb cell line obtained from a number of different laboratories were reexamined with respect to chromosome number and heterotransplantability to the syrian hamster cheek pouch twelve clonal cultures derived from 2 of these sublines were similarly examined three sublines differed from one another and from the kb cell line originally studied which was heterotransplantable with inocula of circa 10 cells only 2 of the sublines could be heterotransplanted with inocula of less than 10 4 cells 5 were heterotransplantable with inocula of 10 4 10 6 cells and 2 failed to heterotransplant even with inocula of 10 6 cells similar differences in heterotransplantability were observed among the clonal derivatives of 2 of these sublines although the modal numbers of these sublines and clonal derivatives were basically similar ranging from 73 to 80 a few lines had a chromosome of sufficient  ly distinctive morphology to serve as a marker there was however no apparent correlation between these minor karyotypic differences and heterotransplantability possible differences between non heterotransplantable and heterotransplantable sublines with respect to the pattern of variability in cytoplasmic protein and cyto  plasmic ribonucleic rna content per cell remain to be studied in detail for i of this series of articles see exc medica cancer 1965 abstr no 2378
MED	1377 establishment of a tissue culture strain jtc 14 from actino  mycin induced ascites sarcoma and its biological characters cell line jtc 14 has been maintained for more than 2 yr and subcultured 93 times cells from the 10th subculture on subcutaneous injection into mice produced tumors identical with those produced by the original cells judged by the time taken to kill mice on intraperitoneal injection the tissue culture cells were not as malignant as the original tumor cells after passage in animals the cells were easily re established in culture in vitro
MED	1378 microcinematographic study of the mechanism of cancerous invasion in cultures of normal tissue combined with malignant cells normal myocardium of newborn c3h mice was cultivated in vitro in contact with homologous sarcomatous cells strain n1 and strain nctc and studied by micro  cinematography for 22 days it was found that the tumor cells tend to move apart and with more vigorous and rapid movements some of them called commandos make their way into the group of normal cells but are arrested wherever they meet a compact group of these cells this then demonstrates on the one hand direct aggresivity of the tumor cells and on the other the group defence of the normal cells
MED	2413 the presence of lymphocytes in long term cultures of newborn mouse thymic epithelium thymic epithelial cells derived from newborn mouse thymic fragments were cultured in vitro for over 22 mth subcultures were started by transferring minute cell sheets obtained by mechanical scraping of the original culture when it was 14 mth old or older lymphocytes many of them with the morphological appearance of plasma cells were seen in the subcultures intact lymphocytes as well as mitotic figures were seen within cytoplasmatic vacuoles of the epithelial cells the possible bearing of these observations on the origin of the thymic lymphocytes is briefly discussed
MED	3748 four separate tumour clones derived from a transplantable pleo  morphic carcinoma of the lung in a heterozygous mouse a metastasising pleomorphic adenocarcinoma in the lung of an untreated hetero  zygous male mouse was successfully transplanted to 4 brothers by the plating technique of henderson and rous by plating multiple small grafts in air bells in the subcutaneous tissues of the new hosts it was possible to select 4 different clones of transplantable tumour for further study the histological peculiarities of different parts of the original tumour were reproduced in the different clones a i ii iii and b retrospective study of the primary tumour and of its metastases provided some interesting clues to routes of metastasis and the selective survival of malignant cells it is concluded that by the cloning of transplantable cells at the first serial passage valuable information about the histogenesis and potential malignancy of the primary tumour can be obtained lastly the highly malignant character of 4 clones of tumour cells apparently derived from the familiar clinically benign adenoma of the mouse lung may be of some interest from the point of view of prognosis based on histology
MED	2379 in vitro culture of pulmonary tumors in hamsters caused by adenovirus 12 it is known that the adenoviruses 12 and 18 provoke malignant tumors in the new born hamster the authors made a study of the histogenesis of these tumors and examined the specific changes brought about in the cells by the virus infection malignancy presence of viral antigen reactions to superinfection when new born hamsters were inoculated in the chest with adenovirus 12 malignant tumors developed in one or two months in 16 animals out of 22 these tumors presented an epithelial aspect and were of bronchiolo alveolar origin they were transplant  able in vivo if they were cultured in vitro they consisted in the first few cultures of macrophages fibroblasts and epithelium in subsequent passages there was a progressive disappearance of the macrophages and fibroblasts in some cases the culture after seven passages was of a purely epithelial nature and when it was reimplanted into hamsters at this time it gave rise to the rapid development of an epithelial tumor in the tumor cultures no adenovirus could be demonstrated nor could cultures of the pulmonary tumors or cultures of normal hamster lung be infected with adenovirus it appears that the lung of the hamster in an organotyp  ical culture constitutes a means of choice for the malignant transformation of adenovirus 12
MED	133 demonstration purification and partial characterization of ab  normal hsl antigens in stable human cell lines the existence of abnormal human stable line hsl antigens common to a number of stable human cell lines but absent from normal human tissues and normal human diploid cell strains in tissue culture was demonstrated by agar gel microimmunodiffusion hsl was detected in hela sj hela mba hela s3 chang conjunctiva syvertons embryo esophagus chang liver and j iii it was not detected in henles human intestine or detroit 6 it was absent from two normal diploid strains wi 38 and sj dhl and was not found in a variety of concentrated extracts of fresh human organs hsl was not associated with contamination by pleuropneumonia like organisms pplo of cell lines the purest hsl preparations obtained from hela sj by ammonium sulfate fractiona  tion yielded absorption spectra characteristic of protein and were inactivated by trypsin sephadex chromatography indicated a particle weight of approximately 150 000 hsl was not sedimented at 125 000 x g in 0 02 m po4 buffer activity was virtually completely eliminated after 2 minutes at 50 c 8 minutes at 45 c or 80 minutes at 40 c preliminary studies with fluorescent anti hsl globulin indicated that hsl was not a surface antigen rabbit antisera to purified hsl fractions were not cytotoxic to hela cells the best preparations of hsl still contained a trace of common human antigen and appeared to consist of multiple components active in immunoprecipitation electrophoresis indicated the in  homogeneity of this material
MED	1696 further comparative studies on two isogenic cell lines of autologous origin one of which is tumor producing a single explant of normal lung tissue from an adult female mouse c57bl provided 2 cell lines one remained normal and is referred to as pg the other became malignant and is designated as pt with successive in vitro passages by tryp  sinization the tumour inducing capacity of the pt line considerably decreased its tumour producing capacity as well as its acrobic glycolysis coefficient while the pg line showed no appreciable change results of chromosome studies are de  scribed but proved inconclusive similar experiments were also carried out on cell lines derived from the pt line and their results are discussed
MED	1202 characteristics of human adenovirus type 12 induced hamster tumor cells in tissue culture characteristics of a human adenovirus type 12 induced hamster tumor serially pro  pagated in vitro are described these include small cell size epithelioid appear  ance rapid growth rate resistance to superinfection with a 12 and transplant  ability to weanling hamsters these cells grew either as monolayers or as balls of aggregated cells detached from the glass depending on whether calf serum or horse serum was added to the eagles medium attempts to demonstrate virus activity by subculture of supernatant fluids and lysed cells into hela cells mixed culture with human and hamster cells electron microscopy and inoculation of newborn hamsters with irradiated tumor cells were negative
MED	142 trials of heterotransplantation of human cancer in rabbits and kleisbauer a trials of transplantation of human tumours some 20 almost all carcinomas in the pleural cavity of large rabbits 6 months old flanders weighing 3 kg gave negative results also when cortisone treatment was associated with it though in the cortisone treated animals the necrosis of the tumours was less massive examination of the grafted tumour was carried out at different times from 8 to 365 days after transplantation and was also controlled by radiographic examina  tions detailed description of the giant cell reactions around the tumours and in the adjoining lung
MED	1207 solitary mast cell granuloma histiocytoma of the lung a histopathologic tissue culture and time lapse cinemato  graphic study a pulmonary histiocytoma in a 57 year old woman was studied intensively histo  pathologically and by other techniques abundant mast cells were found within the lesion a previously unreported finding tissue culture studies suggested that the process is reactive rather than neoplastic some plasma cell granulomas of the lung may be mast cell histiocytomas
MED	2773 the value of fluorescence cytology for the cytodiagnosis of pulmonary cancer the paper discusses the test results of 527 tissue samples sent in for the cytodiag  nostics of lung cancer and compares the method of ao fluorochromation with other methods of preparation by means of applying ao fluorochromation the rate of er  roneously positive findings could be reduced the rate of erroneously negative find  ings was somewhat higher but the total diagnostic precision of 93 was 3 higher than in all other methods applied
MED	2774 pitfalls in the clinical and histologic diagnosis of broncho  genic carcinoma a necropsy study of 380 cases of extrathoracic carcinoma revealed that pulmonary metastases occurred in almost 50 of the cases and bronchial metastases in over 25 there were 39 cases 10 3 in the series with clinical features simulating bronchogenic carcinoma and in 24 62 of these cases there was cytologic and or histologic confirmation carcinomas of the pancreas presented the greatest source of diagnostic error accounting for more than one third of the 39 cases the primary site second in frequency was carcinoma of the kidney bronchial metastases were chiefly responsible for the clinical cytologic and histologic findings compatible with the diagnosis of bronchogenic carcinoma secondary growths in the lungs may present roentgenologically as solitary tumors indistinguishable from primary lung cancer metastatic lesions in lymph nodes bronchi and lung may exhibit pleomor  phic features simulating squamous cell carcinoma the diagnosis of bronchioloalveo  lar carcinoma in resected lung tissue is a presumptive conclusion inasmuch as the identical morphological features may be reproduced by metastases from duct or glandular carcinomas the simulation of bronchogenic carcinoma by metastatic tum  ors occurs with sufficient frequency to challenge the diagnostic accuracy of deaths certified as bronchogenic carcinoma with necropsy exclusion of other primary sites
MED	4396 effects of arginine deprivation ultraviolet radiation and x radiation on cultured kb cells a cytochemical and ultrastructural study cultured kb cells derived from a human oral carcinoma grown in monolayers were injured by one of three agents starvation by arginine deprivation or treatment with high doses of either ultraviolet radiation or x radiation the different agents produced changes in nucleolar structure and varying accumulations of triglyceride and glycogen all three agents produced an increase in number and size of lyso  somes these were studied in acid phosphatase preparations viewed by both light and electron microscopy and occasionally in vital dye esterase and aryl sul  fatase preparations ultrastructurally alterations in lysosomes suggested that residual bodies developed in a variety of ways i e from the endoplasmic retic  ulum multivesicular bodies or autophagic vacuoles following all three agents the endoplasmic reticulum assumed the form of rough or smooth whorls and after two of the agents arginine deprivation or ultraviolet radiation it acquired cytochemically demonstrable acid phosphatase activity near connections between the endoplasmic reticulum and lysosomes raise the possibility that in kb cells at least when injured the endoplasmic reticulum is involved in the formation of lysosomes and the transport of acid phosphatase to them
MED	1106 the simultaneous use of extracorporal circulation and hypothermia in the surgery of the heart the operative technique of cardiac surgery under conditions of deep hypothermia with simultaneous use of a pump oxygenator and cardiopulmonary bypass is described in the majority of cases the patients were cooled with water at 2 c and the perfusion volume was reduced by more than 50 during hypothermia in others a gradient of 10 c between blood and water was maintained and the perfusion volume was reduced by less than 50 the data presented show that neither technique leads to hypoxic changes in the cerebrum and internal organs provided the mean arterial pressure is kept between 70 and 90 mm hg during perfusion the overall mortality in the authors 168 cases   most of which had congenital heart disease   was 14 8 in 53 cases of tetralogy of fallot   most of them cyanotic   the vsd was closed by taking a flap of tissue from the crista supraventricularis in this group mortality was 24 5
MED	464 cardiac performance in hypothermia an experimental study of left ventricular power oxygen consumption and efficiency in dogs multiple cardiac parameters have been measured in 30 dogs cooled to 20 c aortic blood temperature the parameters have been expressed both as absolute values and as percentages of normothermic values at normothermia dogs with closed chest had an ascending aorta flow of 154 and a left ventricular external power of 183 of the corresponding values for dogs with open chest both ascending aorta flow and left circumflex coronary artery flow were reduced to 25 of normothermic level at 20 c aortic arch mean pressure was reduced to 50 of normothermic level at 20 c total peripheral resistance was increased to 205 of normothermic level at 20 c left ventricular external power was decreased to 11 of normothermic level at 20 c left ventricular oxygen consumption was decreased to 31 of nor  mothermic level at 20 c mechanical efficiency of the left ventricular myocardium was decreased to 39 of normothermic level at 20 c
MED	3270 tolerance of dogs to deep hypothermia controlled and maintained with a pump oxygenator the advantages of hypothermia of below 10 c for 2 hr induced and maintained by extracorporeal circulation of 200 min were compared to partial bypass of the same duration during normothermia in the normothermic group 9 dogs out of 12 lived in the hypothermic group 6 dogs out of 15 40 survived when perfused at the high flow of 55 cc kg min eleven dogs out of 15 70 survived when the flow rate was reduced to 25 cc kg min when the temperature was below 10 c the death in the high flow group were due mainly to postperfusion lung changes even when low pulmonary venous pressure was assured by venting in the left atrial chamber me  tabolic acidosis occurred in all groups though greater in the high flow with the low flow intermediate between the former and the normothermic group this change to a great degree can be explained by the lung changes
MED	1593 bleeding tendencies associated with profound hypothermia technics in neurologic surgery forty three patients with bleeding intracranial aneurysms were operated on under deep hypothermia and with the aid of extracorporeal circulation the open thorax method was used in 18 cases and the closed thorax method in 25 the following points are made 1 the closed thorax method is considered superior to the open  thorax method in several respects 2 meticulous hemostasis is essential to control the oozing that occurs during extracorporeal circulation under profound hypothermia until the heparin antagonist can become effective and body temperature can return to normal 3 significant thrombocytopenia may develop during extracorporeal cir  culation and inhibition of the thrombin fibrinogen reaction by factors other than heparin may cause a major coagulation defect and may also by mimicking the he  parin effect lead to the excessive use of heparin antagonists 4 pathologic changes in microcirculation during extracorporeal circulation may be determinants of a hemorrhagic tendency
MED	4088 the use of hypothermia and dehydration in the treatment of severe cerebral hypoxia the rational for using hypothermia or cerebral dehydration is to suppress or re  verse progressive or delayed cerebral damage after hypoxia it is suggested that damage of this nature results from injury to the astroglia and oligodendroglia especially the former experimental and clinical evidence favors lowering of the body temperature immediately after any episode of hypoxia accompanied by impor  tant damage to the brain the rational for using dehydration is insecure and its results are uncertain this treatment should probably be reserved for cases in which a raised cerebrospinal fluid pressure has been proved and in which other measures especially hypothermia are either not available or have failed
MED	7828 selective cerebral hypothermia physiology and technic a safe suitable technique for producing selective brain cooling by a perfusion method is described of 15 dogs 7 survived the salient features aiding survival are discussed the use of a direct vasodilator papaverine in the perfusate to relieve vasospasm markedly reduced cooling time and represented the most signi  ficant technical advance over previously described methods an acid base analysis utilizing the siggaard andersen curve nomogram was performed on 4 dogs and no significant acidosis noted during selective brain cooling a definite arteriovenous lactic acid difference developed at hypothermic temperatures indicating the brain may metabolize this substance in preference to glucose at lowered brain tempera  tures the reasons for which were discussed the rate of disappearance of physi  cally dissolved oxygen po2 was measured in the brain following ischemia at dif  ferent temperatures the average rate of disappearance at 20 c was 40 of the rate at 37 c the discrepancy between this finding and the in vitro oxygen utili  zation rate at the same temperature was discussed
MED	948 cardiac activity in cranio cerebral hypothermia the onset of hypothermia rarely alters the heart rate as it deepens to 35 32 the rate slows and at the level of 30 29 it usually amounts to only half its original va  lue at 28 or below the development of bradycardia is observed after warming to 32 the normal heart rate is restored during operations on the abdominal organs the heart rate is only slightly modified the appearance of solitary extrasystoles is rare and is usually associated with stimulation of the diaphragm the most marked changes in the heart rate are observed during operations on the heart especially if it is excluded from the circulation an idioventricular rhythm may develop before the heart stops beating after removal of the ligatures from the venae cavae the nor  mal rhythm is restored as the temperature falls the excitability of the myocardium increases conduction is more resistant areflexia continues even during direct sti  mulation of reflexogenic zones in the surgical stage of cranio cerebral hypothermia it is clear that no significant degree of energy or hemodynamic insufficiency deve  lops whether in experimental conditions or during operations on patients at opera  tion a well marked stabilization of the contractile power of the myocardium may be observed
MED	946 respiration in hypothermia i respiratory pattern and acid base balance in the blood mongrel dogs under light pentobarbital anesthesia were made hypothermic by im  mersing them in ice water and then normothermic in warm water in the course of cooling the respiratory rate and pulmonary ventilation after an initial increase were reduced as the rectal temperature fell and spontaneous respiration was ar  rested at rectal temperatures of 21 25 c alveolar pco2 was increased after an initial slight lowering with the progress of hypothermia arterial ph and standard bicarbonate jorgensen and astrup decreased and the alkalinity of the blood coh ch winterstein decreased markedly during hypothermia these findings suggest both respiratory and metabolic acidosis as the mechanisms concerned in the course of rewarming all these changes disappeared rapidly and completely though the venti  latory stimulation observed as an initial transitory phenomenon during cooling failed to occur
MED	896 studies on blood viscosity and its significance in anesthesia the principles for measuring blood viscosity have been discussed although blood does not behave in a newtonian manner the data obtained in in vitro measurement are useful a modified simple method for measuring blood viscosity relative to nor  mal saline has been described there is essentially no difference in viscosity be  tween fresh blood and heparinized blood and between plasma and serum viscosity varies with the quantity and nature of proteins in plasma and the cellular concentra  tion halothane and thiopental sodium reduce blood viscosity and seem to be indicat  ed in conditions in which there is hemoconcentration and a tendency for red blood cells to aggregate cyclopropane hypothermia and norepinephrine tend to raise blood viscosity and would seem to be contraindicated when the microcirculation is failing
MED	4612 flow considerations in regional cerebral hypothermia it is suggested that low flows are dangerous and may cause anoxia either directly or by interfering with cooling sixty dogs have been subjected to local cerebral hypothermia by the method of femoral to carotid cooling of arterial blood with per  fusion at a predetermined pressure rather than predetermined flow rate the cir  cuit is described and its advantages for clinical use mentioned together with its in  accuracies as a method of scientific investigation these are chiefly concerned with maintenance of systemic blood pressure which may require the injection of pressor agents evidence for reduction in flow at low temperatures is discussed and evidence presented that this is not only due to increase in viscosity but that there is an active spasm manifested by rewarming humps which occur in the cooling graphs mean carotid flow rates were determined by a revolution counter attached to a pump of fixed stroke volume the output of which was linked to the per  fusion pressure and thus determined by the resistance the place of added co2 is discussed particularly in relation to the fall in partial pressure which accompa  nies the cooling of the blood the addition of 5 co2 did not increase total carotid flows halothane had been used as an anesthetic because of its sympatholytic ac  tion it has increased flows by 37 and abolished rewarming humps rheomacro  dex used as a priming fluid instead of blood produced increased flow averaging 75 but did not abolish spasm it is suggested that cooling faster than 1 c per minute is not intrinsically dangerous if spasm is prevented and high flow maintained by the methods described
MED	4613 selective brain cooling produced by cerebral ventricular perfusion hypothermic cerebral ventricular perfusion was applied to dogs shivering appear  ed to be directly related to the cns temperature rather than the peripheral body temperature selective heating of the brain stem produced panting rewarming of the body was retarded by the initiation of heat loss mechanisms controlled cen  trally when hyperthermic perfusion was used shivering disappeared but panting was unaffected by pentobarbital anesthesia cooling of one or both frontal areas and the anterior part of the third ventricle did not significantly affect the respiratory or circulatory systems but brain stem hypothermia produced distinct respiratory and circulatory reactions it is suggested that cooling of the 3rd and 4th ventricu  lar areas may be utilized for anesthetic purposes
MED	1139 optimal coronary flow in the bypassed normothermic and hypothermic heart a series of experiments were conducted in dogs in which bypass flow temperature and direct coronary perfusion pressure were varied coronary flow coronary ven  ous saturation myocardial oxygen consumption mvo2 and coronary vascular re  sistance were assayed coronary flow as a percentage of total bypass flow did not vary appreciably at varying levels of bypass flow induction of hypothermia when total bypass flow is constant results in decreasing coronary flow induction of hy  pothermia when maintaining a constant bypass pressure results in an increasing coronary flow with temperatures down to 22 c further cooling causes a reduction in flow using isolated coronary perfusion at 100 mm hg coronary flow fell and resistance rose during the first 15 min of bypass using isolated coronary perfu  sion at 100 mm hg induction of moderate hypothermia 25 c caused an increase in coronary flow and venous saturation and a decrease in cardiovascular resistance and mvo2 under the same conditions induction of hypothermia to 18 c produced similar changes but caused myocardial hemorrhage and ventricular fibrillation pro  found hypothermia probably leads to excessive fragility of the capillary bed reduc  tion of perfusion pressure to 50 mm hg at near normothermia reduced coronary flow and slightly reduced venous saturation and mvo2 the same reduction of perfu  sion pressure at 18 c produced similar but less marked changes reduction to 25 mm hg at 18 c markedly reduced coronary flow venous saturation and mvo2 initially but with partial recovery later from this data of acute experiments in dogs coronary perfusion using moderate hypothermia about 31 c and 50 mm hg slightly pulsatile mean pressure appears optimal
MED	974 extracorporeal hypothermia without thoracotomy an ex  perimental study in the use of cold for neurosurgery and cancericidal perfusions this paper includes minor clinical notes on open heart surgery and cancer perfusion but contains no experimental information on neurosurgery or cancer perfusions a method of closed chest hypothermic perfusion in 30 dogs is reported the authors utilize drainage of superior and inferior cavae by gravity the volume of venous drainage sometimes enhanced by transfusions or 12 5 low molecular weight dex  tran determined the flow rate cooling was maintained for quite variable periods apparently generally to an unspecified esophageal temperature perfusion time va  ried from 30 min to 4 hr animals with low flows were perfused longer had a high  er incidence of ventricular fibrillation and a very low survival rate eleven ani  mals survived all had pre cooling flow rates above 40 ml kg min good flow rates during the perfusion and only 3 had ventricular fibrillation flow rates and survival were increased in animals receiving low molecular weight dextran four  teen of 15 animals with ventricular fibrillation were defibrillated electrically 8 re  gained adequate cardiac function but only 3 survived some interesting data on regional cooling of the lower half of the body is presented the authors conclude without sufficient evidence that the most important factor in the mortality in hypo  thermic perfusion is the ability to maintain a flow rate approaching the estimated normothermic cardiac output of the animal
MED	2406 profound hypothermia the aim of hypothermia is protection of vital cerebral structures from hypoxia during aneurysm repair profound hypothermia is also valuable in operating on certain cardiac defects which cannot be repaired even with whole body perfusion since the time needed for aneurysm repair often exceeded the safe limit of 8 to 12 minutes without circulation afforded by surface hypothermia of 29 to 30 c the authors have investigated the drew open chest technic the closed chest method and isolated cerebral perfusion the drew technic consists of substituting two pumps for the heart while the patients lungs act as the oxygenator because of its disadvantages the large amounts of blood needed and the morbidity due to intra  cardiac cannulation and median sternotomy a closed chest method was developed using a mayo gibbons vertical sheet pump oxygenator to provide the perfusion and extracorporeal cooling without requiring thoracotomy in cerebral perfusion blood is taken from one artery pumped through a heat exchanger and returned to another artery the authors describe anesthetic technics offer comparisons of the three methods give instructions pertaining to the production of hypothermia and list the problems encountered in the management of these cases
MED	3194 systemic hypothermia via gastric cooling eight dogs underwent gastric cooling for systemic hypothermia each dog was cooled with the balloon filled with a safe volume based on weight 20 ml kg and subjected to cooling with the balloon filled maximally but safely to a pressure of 10 mm hg consistently the latter procedure was far more efficient averaging 2 6 times as rapid for all degrees of hypothermia a decrease in core temperature by 7 c re  quired an average of only 28 4 minutes on comparison with clinical reports of hy  pothermia induced by the usual gastric cooling an improved efficiency of two fold to three fold is still noted
MED	3820 the dubious haemopoietic stem cell function of the lym  phoid cells of the blood autoradiographic studies on dogs the migration fate and turnover of lymphoid cells in blood and bone marrow of irradiated and non irradiated dogs were studied by serial autoradiography with co  ping of the hind legs during the plasma clearance time of h3 thymidine injected into an anterior vein in irradiated dogs the h3 thymidine injection procedure was car  ried out during the early recovery phase following 250 r whole body x irradiation conclusive evidence of transformation of hematogenous bone marrow lymphoid cells into hemopoietic precursors was not found however in the light of the individual grain counts transformation of a few lymphoid cells into hemopoietic cells cannot be ruled out the data obtained from a dog in the very early recovery phase following whole body irradiation strongly indicate such a transformation
MED	3927 studies on growth and cytomorphosis in the thymo lympha  tic systems   with special reference to the influence of the thymus and the thyroid in guinea pigs migratory streams of lymphocytes between different parts of the thymo lymphatic system were evaluated by comparisons between lymphocyte populations in thoracic  duct lymph and arterial and venous blood especially thymic venous blood by re  cording organ weights in sham operated and thymectomized guinea pigs treated with thyroxin or untreated the importance of the thymus and the thyroid for growth and regeneration in the thymo lymphatic system was studied the main results are as follows there is a considerable venous output of lymphocytes with low mito  chondrial content small lymphocytes from the thymus in normal young guinea pigs this explains the much higher incidence of small lymphocytes in blood than in tho  racic duct lymph neonatal thymectomy causes lymphatic hypotrophy with defi  ciency of lymphocytes and pyroninophilic cells in relation to reticular ones body growth and survival of the animals are not affected in the thymus exogenous thyroxin most probably promotes differentiation of large basophilic cells to small lymphocytes resulting in an increased output of small lymphocytes in the lymph nodes thyroxin promotes differentiation of large pyroninophilic cells transitional cells into immature and mature plasma cells the effects of thyroxin on dif  ferentiation are followed by an increased growth of the thymo lymphatic organs characterized by an increased incidence of large basophilic cells and increased weight of the lymphatic organs growth of the thymus and lymph nodes precedes that of the red splenic pulp this delayed splenic response is not due to a transformation of an increased number of immigrated thymic lymphocytes as neonatal thymectomy does not prevent the thyroxin stimulated occurrence of large basophilic cells in the red splenic pulp the thyroxin stimulated growth of the lymphatic system is ac  companied by an increased output of larger lymphocytes through the thoracic duct resulting in an increased number of larger lymphocytes in the blood in postnatally thymectomized animals having a normal or above normal amount of circulating small lymphocytes thyroxin produces a drastic decrease in the number of small blood lymphocytes indicating a decreased delivery and or increased disappear  ance of these cells to and from the blood respectively this decrease in number of small lymphocytes is not seen in sham operated animals as judged by studies of organ weights the thyroxin stimulated growth and regeneration of the lymphatic tissue are influenced antagonistically by thymectomy and synergistically by local factors in involuted tissue
MED	815 the origin of macrophages from bone marrow in the rat skin windows and subcutaneous coverslips were applied to rats in a study designed to identify the tissues in which the precursors of macrophages proliferate lympho  cyte depletion by either chronic drainage from the thoracic duct or 400 rads of x  irradiation failed to suppress the emigration of macrophages or to reduce the pro  portion of them which became labelled after an injection of tritiated thymidine x  irradiation with 750 rads suppressed the emigration and the labelling of the exudate macrophages both were restored to normal when the tibial marrow was shielded during irradiation radioactively labelled cell suspensions obtained from thoracic duct lymph lymph nodes thymus spleen and bone marrow were transfused into syngeneic recipients the emigration of labelled macrophages on to coverslips could be demonstrated only in recipients of labelled bone marrow and spleen cells labelled monocytes were found in the blood of rats which had received injections of labelled bone marrow it was concluded that in the rat bone marrow and to a lesser extent spleen are major sources of the macrophages which emigrate into foci of acute non bacterial inflammation
MED	1786 studies of the leucocyte compartment in guinea pig bone marrow after acute haemorrhage and severe hypoxia evidence for a common stem cell after a large acute hemorrhage the absolute le  vels of neutrophils eosinophils and basophils in guinea pig bone marrow are considerably reduced all stages of differentiation are involved the decline in myelo  blasts and promyelocytes being particularly marked exposure to severe hypoxia also temporarily depresses the number of marrow granulocytes bone marrow lymphocytes are only slightly reduced after a single he  morrhage but in the later stages of severe hypoxia their numbers are greatly reduced assuming the supply of stem cells in the bone marrow is not unlimited the de  crease in marrow granulocytes and lymphocytes follow  ing marked erythropoietic stimulation appears to favor a monophyletic theory of hemopoiesis a heavy demand for stem cells to differentiate into the erythron may temporarily restrict the number entering the leukon the hypoxic animals showed a considerable loss of body weight and the notable reduction of marrow lymphocytes in the later stages of hypoxia may be specifically related to a generalized atrophy of lymphoid tissue using h3 thymi  dine there is evidence of active dna synthesis in guinea pig metamyelocytes although dna synthesis was found in metamyelocytes of normal marrow after hemorrhage these cells form a much larger proportion of the total synthesizing cells in the granulocyte compartment and also the ratio of labeled metamyelocytes to myelocytes is considerably increased microspectrophotometric measurements of the feulgen dna content of metamyelo  cytes after hemorrhage show that there are 2 populations of these cells one group has values typical of resting or nonsynthesizing cells but a 2nd group shows a complete range of dna values up to levels characteristic of those found in dividing cells certain small mononuclear cells with minimal but deeply basophilic cytoplasm are a dis  tinctive group of dna synthesizing cells in marrow af  ter hemorrhage morphologically there appears to be a complete sequence between these cells and procrythro  blasts
MED	3831 relative ability of parental marrow to repopulate lethal  ly irradiated f1 hybrids lethally irradiate c57bl x 101 f1 mice injected with a mixture of 10 million c57bl and 10 million 101 bone marrow cells were repopulated only by the 101 bone marrow cells experiments with other cell mixtures indicated that the 101 marrow was relatively nine times as efficient as c57bl marrow in repopulating lethally irradiated c57bl x 101 f1 mice results from additional strain combina  tions suggested that the behavior of the donor marrows was not determined solely by h 2 factors c57bl marrow which frequently regresses in irradiated f1 mice has shown to be relatively less capable of repopulating the recipient than regularly retained parental marrow the differences in the relative abilities of parental mar  rows to repopulate f1 mice cannot as yet be fully explained they might be corre  lated with physiological differences between the parental marrows or with a micro  environmental advantage of one hematopoietic cell type over another in the irradiated recipient immunological and physiological factors that might favor this selective growth are discussed
MED	3832 pluripotent stem cell function of the mouse marrow lymphocyte bone marrow from normal and polycythemic mice was filtered through glass wool columns to remove cells other than lymphocytes for a given number of nucleated cells filtered marrow was more efficient than the original marrow in repopulating the spleen of an isogenic recipient previously exposed to lethal irradiation the proliferative capacity of both the filtered and unfiltered marrow suspensions ap  peared to be a constant function of the number of small and medium lymphocytes present and not of any other cell type
MED	2045 the effect of unilateral limb shield  ing on the haemopoietic response of the guinea pig to gamma irradiation guineapigs were exposed to 150 r  irradiation whilst approx 1 5 of the total bone marrow was protect  ed by shielding 2 limbs quantitative cell counts of both the shielded and irradiated marrow were combined with observations on the thymus spleen and blood during the recovery period and compared with the effects of whole  body irradiation following whole body irradiation 150 r the thymus shows a delayed secondary cellular depletion coinciding with a marked splenic hyperplasia both phenomena were eliminated by limb shielding the lymphocytes in the irradiated marrow of partially shiel  ded animals continued to show both the overshoot and the secondary fall in numbers which characterize recovery from whole body irradiation 150 r after an initial fall in numbers of erythroid and granulocytic precursors the shielded marrow showed a temporary increase in granulocytopoiesis coinciding with an abortive phase of granulocytopoiesis in the irradiated marrow there was no evidence of any effective colonization of irradiated marrow by cells from the shielded marrow the signi  ficance of these findings is discussed
MED	4311 studies on intravenous transfusion of thymus cells and lymphnode cells iii influence of transfused thymus cells and lymphnode cells on the bone marrow in rabbits transfused with thymus cells and lymphnode cells the peripheral blood and bone marrow were studied the transfusion of thymus cells caused a peripheral lymphocytosis and a diminution of lymphoid cells in the bone marrow of both young and adult rabbits the transfusion of lymphnode cells resulted in a peripheral lympho  penia and an initial increase and a subsequent diminution of lymphoid cells in the bone marrow it is suggested that lymphoid cells in the bone marrow may be lympho  cytes which are stored or discharged according to a variety of conditions further  more thymus cells are thought to mobilize lymphocytes from the bone marrow to the peripheral blood
MED	5041 studies on hypoxia iii the differential response of the bone marrow to primary and secondary hypoxia twenty five adult male guinea pigs were placed in a decompression chamber at a simulated altitude of 14 000 feet for 5 days then kept in ordinary air for 5 days and finally returned to the decompression chamber to be subjected to hypoxia a second time for periods ranging from 1 to 5 days during this period of secondary hypoxia quantitative studies were made of the changes in the blood and bone marrow in secondary as in primary hypoxia there is a significant increase in the nucleated red cells of the marrow in secondary hypoxia however there is a very marked increase in the marrow lymphocytes whereas in primary hypoxia the lymphocytes fall the marrow reticulocytes remain at a fairly constant level despite marked fluctuations in erythropoiesis
MED	1044 an investigation of lymphocyte production in guinea pig bone marrow evidence from a variety of experiments indicates that lymphocytes are produced in guinea pig bone marrow under certain conditions the numbers produced appear to be considerable during recovery from irradiation there are numerous telophases in marrow smears which appear to be forming small lymphocytes moreover many lymphocytes are still found in shielded bone marrow after the rest of the body in  cluding the conventional lymphoid tissues has received lethal or supra lethal irra  diation almost 50 of these cells are formed after the irradiation finally when bone marrow is cultured in the peritoneal cavity of a host whose own lymphocyte production has been suppressed by irradiation small percentages of newly formed small lymphocytes are found in this marrow
MED	103 repopulation of bone marrow in mice number and type of cells required for post x irradiation protection fractionation of cells from mouse bone marrow and autologous mouse spleen indi  cates that the cell responsible for bone marrow repopulation and x irradiation protection resembles the small lymphocyte experiments with injection of different numbers of bone marrow and spleen cells and observations on survival obtained by fractional irradiation of the entire body and of extirpation of the shielded spleen after irradiation indicate that approximately 3 x 10 4 cells of this type are required to provide 50 survival and that approximately this number migrates from the shielded extremity or spleen of a mouse per hour slightly faster for spleen and slower for bone marrow
MED	104 hyperbasophilic cells as an indication of proliferation of bone marrow transplanted to irradiated dogs a study was made of hyperbasophilic cells which appeared following transplantation of bone marrow to 20 irradiated mongrel dogs of both sexes in the main series of experiments the animals were irradiated with a dosage of 600 r using a four tube rum 3 x ray machine voltage 200 kv current 10 ma filters 0 5 cu mm 1 0 mm al target distance 60 cm rate 18 22 r min at 1 2 days after irradiation a suspension of bone marrow cells in a dosage of 10 9   5 x 10 9 nuclear cells was administered i v the marrow was obtained by aspiration from various skeletal bones or by compression from the sternum ribs and other bones a study was made of the morphological composition of the blood and bone marrow before irradiation and at 1 5 10 15 20 25 and 30 days after irradiation and transfusion of bone mar  row and thereafter at 10 15 days intervals smears of blood and marrow were stained with azure ii eosin it was found that distinctive cells with basophilic proto  plasm and frequent incidence of an immature nucleus were present in the blood of dogs following irradiation with 600 r and transplantation of bone marrow hyper  basophilic cells appeared in the blood at 2   4 days after transplantation and attained a maximum 14   21 days later thereafter their number diminished rapidly the trend of number of hyperbasophilic cells coincided with that of other donor elements leukocytes erythrocytes hyperbasophilic cells were not found during acute radia  tion sickness in dogs which were not given injections of bone marrow they were found 3 mth after transplantation of bone marrow to nonirradiated puppies at 2 3 days of age when the irradiation dosage was increased to 800 1 000 r the number of hyperbasophilic cells increased and attained a peak sooner than after the 600 r dosage such cells were formed from the donor cells
MED	172 autoradiographic studies of lymphoid cells in blood and bone marrow of nor  mal and irradiated dogs the migration fate and turnover of lymphoid cells in blood and bone marrow of 4 irradiated and 4 non  irradiated dogs were studied by serial autoradiography with clamping of the hind legs during the plasma clear  ance time of h3 thymidine injected into an anterior vein in irradiated dogs the h3 thymidine injection pro  cedure was carried out during the early recovery phase after 250 r of whole body x irradiation the results on 2 irradiated and 2 normal dogs were described in de  tail migration of lymphoid cells from blood to marrow parenchyma was confirmed in the irradiated dogs con  clusive evidence of transformation of these cells into hemopoietic precursors was not found the relative number of large lymphoid cells the labeling index of the whole population of lymphoid cells and that of small lymphoid cells were increased in irradiated marrow few initially labeled small lymphoid cells could also be observed these data indicate that the pattern of pro  liferation of lymphoid cells is changed in irradiated re  generating bone marrow
MED	175 lysozyme in bone marrow and periph  eral blood cells by means of an indirect histochemical technique the intracellular lysozyme of the formed elements of the peripheral blood and bone marrow was estimated evi  dence is presented that monocytes as well as mature neutrophils and their precursors extending back to the progranulocyte contain significant amounts of this en  zyme a rare mature eosinophil demonstrated a trace of lysozyme activity there was no evidence of lyso  zyme activity in basophils erythrocytes megakaryo  cytes platelets plasma cells tissue mast cells or bone marrow reticuloendothelial cells
MED	1770 proliferative activity of the lymphatic tissues of rats as studied with tritium labelled thymidine cytokinetic data are presented employing quantitation of h3dna in the lymphatic tissues of normal rats serially sacrificed after h3tdr administration a marked difference in the patterns of initial labeling and label loss was observed between the thymus and peripheral lymphatic tissue the data are compatible with other indica  tions of rapid cell renewal in the thymus there is suppression of initial uptake of h3tdr into the dna of each large lymphocytic progenitor cell in the thymus appa  rently because of a feedback of thymidine containing material from small lympho  cytes in the thymus depletion of the thymus of small cells as by operative stress or whole body x ray leads to a marked increase in the uptake of h3tdr into the dna of large thymocytes this finding which is in agreement with the previous findings of sugino et al suggesting transfer of thymine nucleotides from small thy  mus lymphocytes to precursor cells may or may not be related to the apparent transfer of dna label between thymic cells the evidence for the latter consists of the curvilinear dilution of the dna label in the thymus proliferating cell population and the relationship between the rate of dna label dilution in large cells and the dna in the small cells in the thymus after the dna label in progenitor cells in the thymus and lymph nodes has entered the small cell population the subsequent dilution of grains in these dividing cells follows the same slope as the loss of radio  activity from the entire lymph node there is a long retention of some h3dna label in the dividing lymph node cell population this suggests that the loss of radioacti  vity from the dividing cells and from the small cell population as a whole occurs e  qually this pattern prevails regardless of whether the percentage of large and small cells is altered experimentally these findings can be explained by an inter  change of the dna nuclear label between small lymphocytes and large lymphocytes this could occur by some process such as phagocytosis or pinocytosis or by trans  formation of the small lymphocyte into a large dividing cell the data fit best with the latter possibility all or any of these mechanisms would lead to an equilibration of the dna label between large and small cells this finding prevents the assign  ment of a finite life span to lymphocytes on the basis of dna labeling kinetics ne  vertheless there appear to be at least two different types of lymphocytes one the thymus type lymphocyte is found in the thymus cortex bone marrow and ger  minal centers of lymphoid follicles the other type found abundantly in the wide  spread peripheral lymphatic tissue shows a very prolonged retention of dna la  bel and is believed to be recirculating immunologically committed cells described by others these cells do not appear to enter the thymus cortex
MED	6674 the free and glucuronic acid bound 17 hydroxy corticosteroids in the plasma of patients with cancer of the breast on i v infusion of acth seventeen patients with advanced mammary cancer were given an infusion with 3 u of acth in 5 hr and 6 others an infusion of 25 u determinations were made of the plasma 17 hydroxy corticosteroids free and bound to glucuronic acid both before and after the infusion in rapidly growing carcinomas high initial values were found for the free corticosteroids more than 20 ug 100 ml of plasma the ratio of free to bound corticosteroids is for stage iv patients 1 8 on the average and approximately 1 for the mixed forms stage iv m these ratios are not altered by acth shifts in the ratio of free to bound corticosteroids with acth treatment can be seen depending on the initial value of the free corticosteroids the administration of 3 u is enough and the 5 hr value is some 70 related to a maximal stimulation with 25 u
MED	4179 reduced estriol excretion in patients with breast cancer prior to endocrine therapy the urinary quotient of estriol estrone estradiol 17b eq was measured chemically in women with and without breast cancer as an in  dex of the ratio of noncarcinogenic impeded es  trogens to mammary carcinogenic estrogens in 34 controls the median eq was 1 3 before and 1 2 after menopause with only 21 of the patients sub  normal in 26 breast cancer patients without endo  crine treatment or recent surgery the median eq was 0 5 and 0 8 respectively with 62 of the pa  tients subnormal after major surgery or hormo  nal therapy only 23 of 53 patients were subnor  mal no remissions being observed unless the eq rose toward normal matching of 24 controls and patients in pairs by age and ovarian status in the wilcoxon test indicated that the decreased eq ex  creted in untreated cancer was significant at the 0 2 confidence level the marked increase in eq induced by castration and androgen estrogen and corticosteroid therapy suggests that normaliza  tion of a precancerous metabolic imbalance be  tween impeded and active estrogens derived from ovarian and adrenocortical sources contributed to arrested growth of estradiol dependent metastases
MED	1107 urinary excretion of estrone estradiol and estriol by pa  tients with breast cancer and benign breast disease premenopausal patients with breast cancer and benign breast disease appear to ex  crete a significantly lower percentage of the total estrogen as estrone and a signifi  cantly higher percentage as estriol than women in the premenopausal control group there was no significant difference in the excretion of total estrogen between cancer groups and controls in good health postmenopausal patients with cancer excreted higher levels of estriol than postmenopausal control groups the increase in estriol excretion cannot be explained by debilitation
MED	5323 systemic effects of androgenic and estrogenic hormones in advanced breast cancer the systemic effects of diethylstilbestrol 45 patients testosterone propionate 48 patients and both hormones 22 patients were studied during the treatment six weeks to over three months of advanced breast cancer in postmenopausal women serious complications included induced hypercalcemia and fluid re  tention physiologic effects such as urinary incontinence diethylstilbestrol virilization testosterone or nausea and vomiting did not necessitate disconti  nuance of treatment androgenic therapy stimulated erythropoiesis observa  tions on the systemic reactions to these hormonal agents definitely contribute to the evaluation of sex steroid therapy
MED	3478 the effect of dehydroepiandrosterone on the 17 hydroxycorti  costeroids in the plasma in various stages of cancer and other diseases of the breast the reducing effect of dehydroepiandrosterone on the plasma corticosteroids is on the average shortened in advanced stage iv cases of breast cancer in 3 groups of patients the lowest corticosteroid levels were found up to 6 hr after infusion of dehydroepiandrosterone phosphate in patients with mastopathy the effect was still detectable 12 hr later in patients with breast cancer in stage iv the initial levels were reached at that time in cases with stages i and ii lesions the findings were intermediate the shortening is attributed to a more intensive transformation of dehydroepiandrosterone in advanced cases of breast cancer
MED	5274 urinary excretion of estrone estradiol and estriol by patients with prostatic cancer and benign prostatic hypertrophy and hopkins c e urinary estrone estradiol and estriol fractions excreted by 21 patients with prostatic cancer 17 patients with benign hypertrophy and 59 clinically well subjects were assayed to determine whether differences exist absolute levels of estrone estradiol and estriol fractions were not significantly different the excretion of relatively lower levels of estrone and estradiol and relatively higher levels of estriol by patients with prostatic cancer compared to clinically well subjects resulted in significantly lower proportions of the total estrogen being excreted as estrone and estradiol differences in the proportions of estrogen frac  tions between patients with benign hypertrophy and clinically well subjects were not significant with the exception of a significantly higher percentage of the total estrogen being excreted as estrone by the patients with benign hypertrophy differences between that group and the cancer group were also not significant clinical variations between the 3 groups and within the cancer and hypertrophy groups preclude assignment of significant differences to prostatic dystrophies alone cancer patients experiencing inanition due to a loss of appetite excreted significantly lower levels of estrone than patients who reported no loss of appetite significantly lower levels of estrone were excreted by patients with benign hyper  trophy hospitalized 6 days or more compared to patients hospitalized 5 days or less a significantly higher urinary estrone androsterone ratio was present in the cancer group than in the clinically well group it is not believed however that an arbi  trary ratio can be used to suggest an internal estrogen androgen imbalance
MED	28029 enzymic synthesis of steroid sulfates ii presence of steroid sulfo  kinase in human mammary carcinoma extracts extracts of human primary and secondary mammary carcinomas were shown to contain steroid sulfokinase s in every case examined examination of normal breast tissue surrounding the tumors revealed very weak steroid sulfokinase activity in some instances this was thought to be due to the fibrous nature and poor cellularity of the normal breast tissue normal ovarian tissue specimens obtained from cancer patients undergoing oophorectomy did not generally contain the enzyme but trace levels were detected in 1 of 5 specimens examined steroids without necessarily showing conversion to steroid sulfate were observed to increase the incorporation of s35 sulfate into one of the products formed enzy  mically on incubating breast tissue extracts with s35 adenosine 3 phosphate 5  phosphosulfate
MED	3752 steroid excretion in early breast cancer patients with advanced breast cancer who subsequently fail to respond to adrenalec  tomy or hypophysectomy have been found to excrete abnormal amounts of the urinary metabolites of androgen and cortisol when similar measurements are carried out on patients with early breast cancer it is found that approximately half the cases presenting for mastectomy are also excreting abnormal amounts of these steroids subsequent follow up shows that these cases tend to have a poor progno  sis and a trial had therefore been started in which the abnormality is being cor  rected in addition it seems possible that the deficiency in adrogen excretion may precede the onset of the disease this problem is being investigated in a trial involving urinary steroid estimations in 5000 normal women the measurements are being compared with the subsequent development of breast cancer
MED	2365 the excretion of oestrone pregnanediol and pregnanetriol in breast cancer patients i excretion after spontaneous menopause the urinary excretion of oestrone pregnanediol and pregnanetriol was determined in a series of postmenopausal breast cancer patients receiving no endocrine treat  ment the steroid excretion was studied both in relation to the age of the patients as well as in relation to the time elapsed since the last menstrual cycle the results indicate that after an initial slow decrease from the age of the menopause onward the excretion of oestrone and preganediol increases again a new maximum was found in the group 10 15 yr after the menopause the excretion of pregnanetriol however remains relatively constant after a more rapid fall during the first few years after the menopause
MED	2366 the excretion of oestrone pregnanediol and pregnanetriol in breast cancer patients ii effect of ovariectomy ovarian irradiation and corticos  teroids the urinary excretion of oestrone pregnanediol and pregnanetriol was determined in breast cancer patients at different stages of their endocrine treatment the results demonstrate that corticosteroids in substitution doses cortisone 50 mg daily or prednisone 10 mg daily divided in 4 daily doses are very effective in depressing the excretion of all 3 steroids in postmenopausal patients this is in agreement with the clinical impression that these easily tolerated small doses of corticosteroids have the same therapeutic effect as adrenalectomy in patients with breast cancer the results indicate that the ovaries may contribute to the production of oestrogens for many years after the menopause and that this production is depressed by ovarian irradiation this is in agreement with the clinical observation that ovarian irra  diation has a therapeutic value in postmenopausal women with breast cancer
MED	414 estimation of the urinary 17 ketosteroids in the diagnosis of car  cinoma of the prostate in 33 patients with histologically confirmed carcinoma and in 37 patients with confirmed benign hyperplasia of the prostate the amount of neutral 17 ketosteroids was estimated in 24 hr samples of urine the results revealed that contrary to reports in the literature this diagnostic method is quite unreliable raised 17 ketosteroid levels were found also in a high percentage of control subjects moreover the estimation of 17 ketosteroids is a very laborious biochemical method and involves a relatively great experimental error
MED	2820 influence of small doses of corticosteroids on the excretion of pregnanetriol and oestrone in a series of patients with breast cancer excretion of oestrone and pregnanetriol was determined with administration of corticosteroids oestrone excretion in postmenopausal women diminished 67 a decrease of pregnanetriol ex  cretion values was observed as well evidently a low oestrone excretion in patients subjected to corticosteroid therapy is due to a depression of the adrenal function
MED	5062 urinary ii deoxy 17 oxosteroids in british and japanese women with reference to the incidence of breast cancer japanese women excrete more andosterene 5a relative to aetiocholanone 5b than do british women living in tokyo the mean 5a 5b ratio in the former is 1 3 and in the latter 1 0 and these means differ significantly the ratio is markedly affected by thyroid function and thyroid disease has been reported to affect the incidence of breast cancer which in japan is only one eighth of that in white women in north america or great britain
MED	5318 the plasma 17 ketosteroids and 17 hydrocorticosteroids in women with breast cancer in 100 women in the menopause with breast cancer the mean level of plasma 17  ketosteroids 17 ks and 17 hydroxycorticosteroids 17 ohcs was significantly higher than in normal women of equivalent age in 67 young women only the level of the plasma 17 ohcs was significantly higher than normal in menopausal women with breast cancer whether treated or not there is no correlation between the level of the plasma 17 ks and that of 17 ohcs
MED	5319 urinary porter silber chromogens following intravenous metho  pyrapone and acth in patients with breast cancer urinary porter silber chromogens have been measured in 2 groups of patients with breast cancer before during and after intravenous methopyrapone and acth administration the control group consisted of females free of disease 5 years or more following mastectomy while the study group had documented metastatic disease no significant difference in the urinary porter silber chromo  gens was found between the 2 groups on any day during the course of the study and were within the range of normal as measured in this laboratory it is concluded that the functional reserve capacity for both pituitary acth secretion and adreno  cortical steroidogenesis in patients with advanced metastatic breast cancer is rela  tively normal
MED	2349 amyloidosis in the autopsy material of the pathology department of tuberculosis institute warsaw in 1945 1962 the autopsy material of the pathology department of the tuberculosis institute in 1945 1962 included 1218 postmortem examinations of patients who died from tuberculo  sis in 111 cases tuberculosis was complicated by amyloidosis in 1945 1957 amy  loidosis accounted for 8 7 of the cases in 1958 1962 this percentage was 10 8 there was no difference in the incidence between men and women the only difference between the two sexes was that the peak tuberculosis fatality curve in men was in the 40 60 years age group and that of amyloidosis at the 20 30 age group while in women the greatest number of death from tuberculosis was in the 20 30 age group and from amyloidosis in the 30 40 age group
MED	766 certain features of the haemogram in patients with pulmonary tuberculosis complicated by amyloidosis russian regression of amyloidosis in the early stages seems possible and for this reason russian clinicians are exploring the possibilities of finding means of early diagnosis of this complication the author studied 300 complete clinical blood analyses made in 60 patients viz 30 with chronic fibrocavernous and cirrhotic forms of tb com  plicated by amyloidosis and 30 with the same forms of tb without amyloidosis from detailed serial study of the haemogram in patients with pulmonary tb it is possible to diagnose associated amyloidosis of the internal organs in its initial stage the presence of amyloidosis of the internal organs can be inferred from the following changes in the blood picture a the appearance of normochromic and hypochromic anaemia in patients with various forms of tb with the exception of tb of the kidneys intestinal tract or larynx and of caseous lymph nodes b progressive increase in the leucocyte count with a neutrophil shift to the left not corresponding with a phase of quiescence of the main disease c consistently high esr in the absence of an active process d thrombocytosis in the phase of subsidence of a flare up and also changes in the thrombocytic formula tending towards the appearance of de  generative forms and old and mature thrombocytes
MED	1319 diffuse tracheo bronchial amyloidosis a rare variant of a protean disease a patient with diffuse tracheo bronchial amyloidosis is described brief clinical details supplement those published in a previous report prowse 1958 and are followed by an account of the necropsy findings and the histological appearances at the site of amyloid deposition the literature is reviewed and arguments are advanced in favour of a common aetiology for amyloidosis in all its forms if this acts through the immunity mechanism it is suggested that variations in the site strength duration and frequency of the antigen stimulus and the antibody response may determine the nature and distribution of the amyloid deposits
MED	2091 modern methods of treatment of visceral amyloidosis in patients with pulmonary tuberculosis russian the immediate and long term results of treatment during 1945 1962 of 414 patients with pulmonary tuberculosis complicated by amyloidosis were studied hormonal corticosteroid therapy is the pathogenetic treatment for visceral amyloidosis and is indicated in the proteinuric and early edema hypotonic phase of amyloidosis when the functional capacity of the kidneys and the liver is still adequate in the azotemic phase of amyloidosis hormonal corticosteroid therapy is not indicated since it leads to rapid deterioration in the patients condition since hypoxemia is one of the main factors in the pathogenesis of amyloidosis oxygen therapy is rational patho  genetic therapy for patients with pulmonary tuberculosis complicated by hypoxemia and with symptoms of the proteinuric or edema hypotonic phase of amyloidosis without ascites in the form of subcutaneous introduction of oxygen or oxy  geno peritoneum in patients with pulmonary tuberculosis surgical interven  tion on account of the main process is indicated only in the early stages of amyloi  dosis when pronounced functional disorders of the kidneys and liver are absent co  joint therapy using protein vitamins particularly ascorbic acid hormonal corticos  teroid preparations oxygen and desensitizing agents and elimination of all foci of infection is indicated in treatment of pulmonary tuberculosis with even the earliest signs of amyloidosis
MED	2317 the use of needle biopsy of the liver in the diagnosis of visceral amyloidosis in patients with pulmonary tuberculosis russian the results of 86 puncture biopsies of the liver in 84 patients with pulmonary tuber  culosis 55 men and 31 women aged from 18 to 73 yr for the purpose of diagnosing amyloidosis are reported puncture was performed when amyloidosis was suspected on the basis of the case history destructive process of more than 2 3 years duration clinical signs in the form of enlargement of the liver and spleen edema changes in the blood picture and blood protein formula and changes in the urine proteinuria cylindruria isohyposthenuria amyloidosis was diagnosed or its presence surmised before puncture in 23 patients the puncture biopsy confirmed the diagnosis in 14 and refuted it in 9 of them in 8 patients without clinical symptoms amyloidosis was diagnosed on the basis of the puncture biopsy alone in 9 cases with fatal out  come the post mortem findings coincided with the results of the bioptic puncture of the 62 patients in whom amyloidosis was not detected by biopsy 31 had moderate dystrophic changes and 9 had marked dystrophic changes while in 22 cases no patho  logical changes were found 6 of these patients later developed amyloidosis these findings supported the contention that liver amyloidosis is linked with dystrophic changes in the epithelial cells marked dystrophic changes can precede amyloidosis or may occur simultaneously with it moderate dystrophic changes are quite common in patients with an exacerbating tuberculous process in the lungs the wide applica  tion of bioptic puncture of the liver in indicated cases can increase our knowledge of the morphological changes taking place in the liver in tb
MED	2701 the role of certain additional factors in the development of amyloidosis and its prophylaxis in patients with pulmonary tuberculosis russian in patients with chronic fibrocavernous tuberculosis of the lungs any toxic aller  gic side reactions to antibacterial therapy chronic foci or infection and diseases with an allergic component can contribute to the development of amyloidosis the early detection and clearing of chronic foci of infection and effective measures against even mildly pronounced toxic allergic side reactions are of prime impor  tance in the prevention of amyloidosis the unsystematic and prolonged administra  tion of antibacterial preparations along with their toxic side effects tends to in  crease the incidence of amyloidosis in patients with chronic fibrocavernous pulmon  ary tb individual constitutional factors are of great importance in the development of side effects side reactions to chemopreparations in cases of hypofunction of the liver and kidneys and autonomic dysfunction promote the development of dys  trophic processes as is confirmed by the high frequency of toxic allergic reac  tions in patients with fibrocavernous pulmonary tb who later develop amyloidosis the administration of desensitizing drugs to patients showing side reactions there  fore helps to prevent amyloidosis in cases of chronic fibrocavernous tb and chemo  therapy should be automatically combined with the administration of desensitizing and stimulatory drugs in this class of case
MED	1835 the decrease of the steroids in the urine in the course of lung tb the therapeutic value of their increase after calciferol quantitative determination of the urinary steroids in 38 patients with extensive ul  cero caseous pulmonary tb confirmed that the 17 ketosteroids are always decreased in these cases calciferol in the form of one ampoule of vit d2 of 600 000 u every 10 days in combination with active tuberculostatic drugs in the majority of the cases leads to an increase of the urinary 17 ketosteroids from 50 to 100 in 2 mth it appears that the calciferol exerts its action through proteolysis it stimulates the liquefaction and evacuation of the caseous material this proteolytic effect is related to that of the mineralocorticoids which are phlogistic and proteolytic sub  stances calciferol offers the advantage over these substances that it does not affect the electrolytes and is well tolerated by the organism for this reason good results may be expected from its administration in cases of extensive pulmonary tb in which the myc tuberculosis has remained sensitive to the administered tuberculostic drugs but nevertheless does not proceed towards recovery because of the marked caseous lesions in such cases calciferol treatment leads to a rapid and pronounced decrease of the radiological shadows improves the general condition and also modifies the steroid metabolism rendered abnormal by the disease
MED	1837 development of amylosis in less than 2 months in the course of a primary tb infection the case is reported of a previously healthy young north african male in whom a post primary ulcero infiltrative tb in less than 2 mth led to the development of visceral amyloidosis which could be confirmed by biopsies of the kidney and liver during treatment with antibiotics the hepatic amyloidosis regressed parallel with the improvement of the tb and the biological signs of the renal amyloidosis dis  appeared with the exception of a pronounced proteinuria the persistence of which renders the long term prognosis highly doubtful
MED	2216 the relations between lupus erythematosus and diseases of the lympho reticular system a case report of a patient with led aged 48 years who developed secondarily a lymphoblastic sarcoma when the sarcomatous degeneration of the lympho  reticular system became apparent the serological and immuno hematological tests typical for led were negative to interpret the observation 62 further patients with lymphogranuloma lymphosarcoma leukemias other malignant tumors sar  coidosis and tuberculosis were investigated serologically and immunohematolo  gically antinuclear factors were found in serum of 4 patients with lymphogranulo  ma one patient with anaplastic carcinoma and one patient with metastasizing mixed parotid tumor the identity of the antinuclear antibodies with those found in led could not be proved by different methods the importance of certain diseases of the lympho reticular system for the production of antinuclear factors was dis  cussed
MED	4417 value and significance of the prednisolone test in diseases of the kidney twelve normal subjects 18 cases of tubulo interstitial nephropathy 12 cases of glomerular nephropathy and 17 cases of other renal disorders were investigated all patients were given a prednisolone test with urine culture before and after the test and in many instances determination of the urinary osmolarity the urinary sediment was examined with the sternheimer and malbin staining technique and with the peroxydase stain to investigate the urinary cytology with the criteria adopted the test was negative in the normals and was positive in 61 1 of the cases of chronic pyelonephritis and in 12 1 of the remaining cases of unequivocally non  infectious renal disease the increase of the urinary bacterial count after cortico  steroid administration and investigation of the various components of the urinary sediment also supplied useful diagnostic information on the contrary the stern  heimer malbin stain for the urinary sediment proved of little use
MED	564 tumoral amyloidosis of the lung an incidental finding at necropsy on a woman aged 95 was a tumor like mass 8 5 x 6 5 x 6 cm in the lower lobe of the left lung the detailed structure of this may suggested angioma of hamartoma the stroma and some vessels contained amyloid amyloid is not uncommon in the stroma of tumors a summary of 17 tumoral amyloid cases reported by others is included
MED	7364 experimental amyloidosis in immunity much of interest in the mechanism of experimental amyloidosis as a result of the parenteral introduction of foreign protein has been centered around the nature of the links leading to cytological and biochemical changes in tissues and body fluids some of the authors suggested that such links may be of immunological nature there is however no clear cut proof either in favor of or against the theory of an immunological origin of amyloid since injection of proteins during the perinatal period prevents an immune response when the animal is subsequently challenged with the same antigen the authors studied amyloidosis caused by casein in mice treated after birth with this protein mice exposed soon after birth to casein ac  quire an immune tolerance to this antigen this was demonstrated by the absence of circulating antibodies as measured by the disappearance of i labeled casein from the circulation and by means of passive hemagglutination tests with ascitic fluids both tolerant and control animals developed amyloidosis to the same extent the results imply that the pathogenesis of amyloidosis does not rest upon a classic immunological basis they do not exclude the possibility that the disease may be due to some auto immune process
MED	3535 electron microscopic study of six cases of human renal amyloidosis this study is particularly concerned with a the basal membrane in the different stages and b the intercapillary spaces in the early stages the conclusions may be put as follows 1 the amyloid substance seems to have a fibrillar structure from the start 2 when the walls of the peripheral capillary loops are thickened by voluminous amyloid deposits the hyaline aspect of the primitive basal membrane persists but its structure is altered by the presence of multiple amyloid fibrils 3 on the other hand in the initial stages amyloid fibrils cannot be seen in the lamina densa of the basal membrane they only appear on the epithelial and endo  thelial surfaces of the membrane this suggests that amyloidosis represents an abnormal precipitate of extrinsic origin rather than a transformation in situ of the basal membrane 4 in the very early stages of amyloid infiltration into the glomeruli the fibrillar substance is found first in the intercapillary spaces only later does it reach the peripheral capillary walls
MED	3544 morphology and development of infectious toxic affections of the kidneys in pulmonary tuberculosis russian the kidneys of 75 patients dead from tb of the lungs and of 30 rabbits with pulmonary tb were examined the first lesions develop in the glomeruli followed by changes in the stroma and tubules infectious toxic affection of the kidneys is a complex and prolonged process involving organic immune reactions lymphostasis venous stasis and finally nephrosclerosis infectious toxic lesions were found in one third of the patients who died of pulmonary tb these changes had produced clinical manifestations on the basis of which the following affections had been diagnosed nephritis nephrosis amyloi  dosis antibacterial therapy of the pulmonary process reduced the renal lesions how  ever severe infectious toxic affection of the kidneys may develop after recovery from pulmonary tb
MED	3553 diffuse nodular amyloidosis of the lungs in a 59 year old man who 12 yr previously had ceased working in an aluminium factory and who had died from respiratory insufficiency the postmortem examination revealed disseminated nodules in the lungs the nodules were sharply defined of a greyish color and of a doughy consistency and could easily be removed from their capsules the diagnosis of amyloidosis was made on the basis of the histological findings the staining qualities of the material its intraseptal and periarteriolar localization and the existence of plasmocytic infiltrates and foreign body giant cell granulomas amyloid deposits were also found in the spleen kidney and some coronary branches in regard to the pathogenesis it is suggested that the exposure to aluminium products for more than 10 yr might have constituted a predisposing factor
MED	3724 the bacterial induction of homograft sensitivity ii effects of sensitization with staphylococci and other microorganisms heat killed strains of staph aureus and staph albus can induce in guinea pigs a state of altered reactivity to skin homografts which is indistinguishable from that which results from sensitization with homologous tissues or group a streptococci challenge of suitably prepared recipients with 1st set skin homografts obtained from unrelated randomly selected donors elicits white graft reactions or accelera  ted rejections of such grafts other bacteria tested included lancefield streptococcal groups b c d e g h l and o pneumococcus types ii iii xiv and a rough strain c xerosis b subtilis e coli a aerogenes s typhimurium pr vul  garis n catarrhalis h influenzae and 2 human virulent strains of myc tuber  culosis none of these microorganisms was active in the induction of homograft sensitivity in the guinea pig pretreatment of recipients with gram negative bac  terial suspensions was associated with a slight increase in the mean survival time of 1st set skin homografts results of this study suggest the presence in staphylo  cocci as well as in group a streptococci of antigens related in their biologic ef  fects to tissue transplantation antigens
MED	6590 structure and function of cross linked dna i reversible denaturation and bacillus subtilis transformation reaction of nitrous acid with dna results in covalent linkage of complementary polynucleotide strands the resulting material denatures reversibly and retains biological activity in bacterial transformation
MED	4958 the mechanism of messenger rna replication in bacteria the transformation of bacillus subtilis sb25 his tryp by two linked genetic mar  kers under the action of hybrid molecules of dna was investigated the molecular hybrids were obtained by thermal denaturation and annealing of a mixture of two dnas each one extracted from a single auxotrophic strain h25 his and 168 tryp  the formation of the heterozygous dna double helices was proved by special experi  ments the transformation procedure excluded dna synthesis by recipient cells prior to the formation of enzymes for histidine and tryptophane synthesis it was found that heterozygous molecules of dna are able to transform in these conditions the double auxotrophic cells to prototrophic ones this means that both strands of the dna double helix can serve as templates for the m rna synthesis the possi  bility of a secondary replication of m rna outside the chromosome under the action of rna polymerases using rna as a primer is discussed
MED	2567 the molecular basis of histidase induction in bacillus subtilis bacillus subtilis growing at 37 on glutamate as only carbon source is induced to form histidase by l histidine this enzyme converting histidine to urocanic acid was isolated in a purified form a highly sensitive and convenient assay for the induced enzyme is described and applied to show that histidase appears in the cell 5 min after addition of the inducer histidase synthesizing capacity appears after 2 min and decays exponentially after addition of actinomycin an inhibitor of dna dependent rna synthesis the half time value of histidase synthesizing capacity of 2 4 is high compared with the half time value of messenger rna the histidase formation after addition of actinomycin was not only due to protein synthesis directed by accumulated m rna but also by conversion of an enzymatical  ly inactive protein present on the moment of actinomycin addition and product of the specific m rna to the active enzyme the existence of this enzyme pre  cursor was shown by means of experiments performed in the presence of chlor  amphenicof finally numerical values for the steady state of histidase synthesis reached 9 min after addition of the inducer are calculated on the basis of ki  netics of histidase synthetic capacity precursor and enzyme formation the cell contains sufficient precursor to form approximately 100 molecules of histidase the cell produces approximately 50 molecules histidase per min the cell ac  quires and loses every minute the capacity to make 15 molecules of histidase per minute the maximal enzyme level is 15 000 molecules per cell
MED	2542 symposium on the fine structure and replication of bacteria and their parts ii bacterial cytoplasm comparison of the fine structure of the cytoplasm of the bacterial cell with that of the cell in general reveals important differences leading to the conclusion that in the bacterial cytoplasm there is little differentiation into separate functional en  tities there is no nuclear membrane and fine fibrils appear to extend from the nucleo  plasm into the cytoplasm where they may expand in all directions the cytoplasm is not necessarily intersected by membranous profiles of special configuration as is borne out by e coli b and other gram negative organisms when membranous profiles of special configuration are present as in the gram positive b subtilis these do not appear differentiated into clearly definable endoplasmic reticulum golgi substance microbodies etc and mitochondria as for kinetosomes the presence of centrioles is perhaps not very likely the experiments in which tellurite is re  duced in the cells suggest that there are structures at the base of the flagella with reductive capacity however upon application of the tetranitro blue tetrazolium technic to b subtilis these are not stained they are presumably identical with basal granules the membranous structures in b subtilis are called chondrioids by the author because probably one of their functions is that they are the sites of the respiratory enzyme chain in the gram negative p vulgaris the probable site of the respiratory chain has a structure very different from that in the bacillus it is not clear whether membranes are involved in their structure morphologically even in b subtilis chondrioids differ fundamentally from the mitochondria in that they are not built up from composite membranes they are extensions of the plasma membrane and they may not be completely closed systems regarding this last point it was observed that chondrioids may possibly stand in open connection with the cells environment since its lumen is not separated from the cell wall by a plasma membrane although as yet nothing is known about this it does not seem to be precluded that these membranous organelles may function also as intracellular transport systems contrary to porters ideas about er the chondrioids are not extensions of a nuclear envelope but of the plasma membrane on the other hand they are in the nuclear area in direct contact with the nucleoplasm and therefore perhaps they need not carry in their interior some dna as is now becoming known for ordinary mitochondria the chromatophore vesicle is of a simple structure and in connection with the plasma membrane it is covered by a single membrane and thus resembles the granum disc but it is much smaller in tissue cells an im  portant function of the er is the support of protein synthesis by ribosomes bound to their surfaces evidence is now accumulating that the active complexes for poly  peptide synthesis in bacteria are also membrane bound and are series of 70s ribo  somes using the same messenger rna molecule it remains a contradictory situ  ation that the particles obtained here through release of cytoplasm from protoplasts in diluted rather crude fixing media and identified as ribosomes could not be recognized as such in thin sections of the ryter kellenberger fixed protoplasts this point is much in need of clarification but even if the cytoplasm in the thin sections of the protoplasts is in a state of dispersion brought about artificially it is still apparent from the various micrographs that basically the cytoplasm is a network of presumably linear arrays with many interconnections due to fibrillar systems fibrils from the nucleoplasm penetrate deeply into the cytoplasm the presence of fine fibrils of various thicknesses electron densities and orientations makes high resolution study of the cytoplasmic details an intriguing prospect from which much fundamental information can be gained the organizational pattern on the ultrastructural level in bacteria reveals fundamental similarities and divergen  cies from that in the cell in general
MED	906 molecular mechanism of genetic recombination in bacterial transformation the mechanism of dna incorporation into the recipient cell chromosome was in  vestigated in a b subtilis transformation system the recipient cells were auxo  trophic for 2 linked markers hybrid dna used for transformation was heterozy  gous for one of these markers no differences in transformation activity were found when the effect of native and hybrid dna was compared according to the authors this observation is easily explained if we accept that each of both complementary strands of the donor dna can be incorporated into the recipient chromosome with equal probability the results on the segregation of genetic characters in the pro  geny of transformed cells are also consistent with the model of independent incorpo  ration of both dna strands some calculations were done on the probability of the integration of a single dna strand carrying a particular genetic marker and on the probability of recombination leading to double transformants
MED	1520 multiplication of bacteriophages the reproduction of bacteriophages requires the participation of bacterial metabol  ism synthesis of the viral protein components is accomplished by the same me  chanism as ordinarily produces bacterial proteins however for the synthesis of nucleic acids dna or rna enzymes may be required which are not present in non  infected bacteria their formation is then induced by the virus itself the fundamental biological processes of replication transcription and translation are discussed in this context
MED	1361 the mechanism of histidase induction and formation in bacillus subtilis the role of the inducer l histidine in the synthesis of histidase l histidine am  monia lyase in b subtilis was investigated it was found that induced cells poisoned with actinomycin an inhibitor of rna synthesis lose their capacity for the forma  tion of a protein precursor of histidase at a rate which is independent of the presence or absence of the inducer these results show that the inducer does not increase the intracellular level of histidase specific messenger rna by preventing the des  truction of the major portion of this material the fraction that is engaged in pro  tein synthesis the possibility has not been excluded that the inducer exerts its effect by bringing about the stabilization of the messenger rna that is still attached to dna or has not yet become attached to ribosomes alternatively the inducer may actually stimulate the synthesis of histidase specific messenger rna the conver  sion of the precursor to active enzyme appears to involve polymerization of mono  mers rather than the release of ribosome bound inactive enzyme
MED	1362 the synthesis of phage and host dna in the establishment of lysogeny a method of extraction is described which prevents excessive fragmentation of bac  terial dna the larger bacterial dna can then be separated from the phage dna on sucrose gradients the relative amounts of phage and host dna made at various times during infection of s typhimurium with phage p22 leading to lysogeny have been determined phage specific dna synthesis begins at about 4 min continues to increase for 2 4 min and then decreases until complete repression is attained at 16 min autonomous phage dna synthesis remains repressed from then on bac  teria specific synthesis proceeds at a decreasing rate until about 16 min when almost complete inhibition is reached when dna synthesis recovers in the in  fected cells only host specific material is made a new species of dna which is made only when phage dna is synthesized has been detected the possible implica  tions of these findings in the understanding of the lysogenic interaction is discussed
MED	438 lag period characterizing the entry of transforming deoxyribonucleic acid into bacillus subtilis the kinetics of appearance of transformants as a function of time of exposure to dna has been studied a short lag period of approximately 1 min at 37 c is evi  dent when the transformation is terminated with deoxyribonuclease the length of this lag is independent of the genetic trait transferred moreover the lag is unaf  fected by transforming dna concentration by the presence of homologous unmarked dna and by shearing and cross linking of the transforming dna the lag shows a strong inverse temperature dependence the energy of activation is 13 9 kcal the lag is abolished when the transformation is terminated by washing instead of by addition of deoxyribonuclease these results are taken to indicate an immediate adsorption of dna to cells followed by a deoxyribonuclease sensitive period of 1 min during which time the genetic trait is entering the cell these results make feasible an investigation of the configuration assumed by the dna molecule during entry into the cell
MED	439 configuration of transforming deoxyribonucleic acid during entry into bacillus subtilis a correlation was obtained between map distance and the length of the lag period preceding the appearance of pairs of genetic traits after the addition of dna to a competent culture of b subtilis the results are taken to indicate that dna enters competent cells in lengthwise fashion the smallest length of transforming dna which can participate in a recombination event and the number of nucleotide pairs which enter the cell per unit time have been estimated the evidence indicates that only part of the lag period is devoted to the transport of dna into the cell the significance of these results with respect to the mechanism of entry of dna into the cell is discussed
MED	2564 chemical inactivation and reactivation of transforming dna russian the kinetics of the inactivation of linked and unlinked genetic markers by means of hno2 or uv light was studied closely linked markers are inactivated simul  taneously unlinked markers are inactivated independently it seems that the chemical attack on dna impairs a large part of macromolecule including many cistrons it was shown by genetic experiments that chemical inactivation prac  tically does not influence the process of dna inclusion into competent cells by means of viscosity measurements it was shown that the molecular weight and macromolecular properties of dna do not significantly change during chemical inactivation by means of hno2 two explanations for the inactivation of trans  forming activity of dna are discussed 1 structural deteriorations preventing integration of dna molecule into the genome of recipient cell or 2 deletion of a chain unit out of dna chain resulting in wrong reading of code triplets it was previously described in the literature that extensive inactivation leads to a state of dna apparently more resistant than the initial one inactivation does not con  firm to exponential kinetics the authors discuss the coding mistake hypothesis as an explanation for this remarkable fact extensive hno2 or uv light action re  sults in multiple lesions in the dna molecule and leads to reactivation because the deletions restore correct reading of the code in a large part of dna molecule on the basis of this explanation reactivation of chemically injured dna by means of fusion and annealing with homologous but genetically inactive dna or by slight fragmentation of dna by means of ultrasonic vibrations may be expected attempts to achieve reactivation by both methods gave positive results
MED	2565 separation of the transforming and viral deoxyribonucleic acids of a transducing bacteriophage of bacillus subtilis the authors used the transducing b subtilis phage ps 10 and present the fol  lowing experimental data dna isolated from ps 10 is effective for transformation of competent b subtilis cells ps 10 dna is distinguishable from b subtilis dna by its higher density in a cs2so4 gradient and its lower thermal denaturation temperature the transforming activity present in dna from ps 10 denatures at a temperature characteristic of b subtilis dna rather than of viral dna the transforming activity of ps 10 dna bands in a cs2so4 gradient with bacterial dna this data indicated that bacterial dna is incorporated into phage ps 10 without being integrated in the viral dna this incorporated bacterial dna is involved in transduction
MED	2529 repair of damage induced by a monofunctional alkylating agent in a transformable ultraviolet sensitive strain of bacillus subtilis a uv sensitive transformable strain of b subtilis uvr  was unable to carry out host cell reactivation of the virulent bacteriophage spo1 the ratio of the slopes kuvr  kuvr of the uv inactivation curves was 6 8 for cells or for whole phage and 2 for indole transforming dna or for spo1 phage dna measured in a transforming system whole phage inactivated with nitrogen mustard showed greater survival on uvr cells than on uvr  there was no such difference for whole phage inactivated with methyl methanesulfonate whole uvr cells recovered from uv induced damage as determined by an increase in extractable transforming activity during a period of incubation in which net dna synthesis did not occur uvr  cells were unable to reco  ver from uv induced damage but they did recover from methyl methanesulfonate induced damage in similar experiments density labeled h2n15 methyl methanesul  fonate treated uvr cells incubated in h1n14 medium containing h3 thymidine show  ed a 3 fold increase in extractable transforming activity with no formation of new dna molecules as determined by pyknometric analysis the repair of damage in  duced by uv irradiation differs by at least one step from the repair of damage in  duced by methyl methanesulfonate
MED	1451 the biosynthesis of 5 hydroxymethyldeoxyuridylic acid in bacteriophage infected bacillus subtilis when phage e which contains 5 hydroxymethyluracil in its dna in place of thymine infects b subtilis enzyme changes occur in the host organism which can account for the synthesis of the abnormal base deoxycytidylate deaminase increases at least 90 fold and the product of its action deoxyuridylic acid is converted directly into the deoxynucleotide of 5 hydroxymethyluracil by a hydroxymethylase enzyme the activity of thymidylate synthetase which also uses deoxyuridylic acid as substrate decreases rapidly after phage infection
MED	5574 death anxiety in children with a fatal illness the author reports studies of a series of 50 children hospitalized because of fatal illness due to leukemia or some other form of cancer it was postulated that the younger children would experience separation anxiety while the older children would be more likely to experience death anxiety in general the hypothesis was supported by the results of the study there was some evidence to indicate that the younger children perceive death anxiety but deal with it in more symbolic form in older children it was felt that boys tended to react to death anxiety by acting out behavior while girls tended to become depressed
MED	1209 the theory and practice of the family diagnostic ii theoretical aspects and resident education family intervention and observation have proved useful in 3 areas the 1st of these is observation of the psychosocial context in the patient on admission to a mental hospital the phenomenon of extrusion and separ  ation from the family is evident and the need for study of the interaction between the patient and his family milieu is vital the 2nd area where the family inter  view has a major role is resident education the tra  ditional medical education of the ill prepares the stu  dent for consideration of the multifactorial problems of emotional disorder in which balances between mem  bers of a group may be the issue rather than external pathogenes the family interview offers a unique point of observation of factually evident and emotionally con  vincing group data in addition to the observation of family phenomena mutual understanding of others problems is created finally the family interview serves as an instrument for data collection and hypo  thesis seeking in relating individual psychopathology to family adaptations the patient and his family at the time of admission are dealing with a crisis some  times this is traumatic such as the unexpected loss of a young marital partner an unexpected illness or a financial reverse more commonly however it is developmental being a natural part of the life cycle characteristically the developmental task involved in dealing with the crises has been postponed so that one does not see the family at the age specific and ap  propriate time for this task the crisis emerges dis  ruptively because of inevitable biological maturation personal decision or social expectation a primary concern of the leader is to determine what life task is being faced families have a mentally ill member not merely because they are dealing with the vicissitudes of life they are unable to cope with the crisis be  cause of the feelings which are aroused each life cri  sis leads to a particular constellation of effects in any given family these include primarily sadness anger and guilt but there may well be specific affective con  stellations appropriate to different developmental tasks the patients inability to cope with a life crisis is due to his particular adaptation of a style of dealing with feelings that is employed by other members of the family
MED	265 studies in personality ii a bio psychological and experimental approach to problems of human adaptation in modern society experimentally determined fixation ambivalence measures are related to some anxiety estimates obtain  ed from a projective test in a group of male adolescents it is shown that 1 fixation increases with increase in corporal injury anxiety when ambivalence is kept con  stant 2 ambivalence increases with increase in separa  tion anxiety when fixation is kept constant 3 extremely hetero fixated subjects show presence of intense guilt and absence of aggression towards the mother one ef  fect of this system of organizers seems to be suicidal tendencies 4 extremely ambivalent subjects have in  tense separation anxiety one effect seems to be suicidal tendencies combined with high ambition and impaired cognitive capacity
MED	2837 early indicators of outcome in schizophrenia the case material of 50 persons who were seen at a child guidance center in child  hood or adolescence and were later hospitalized with schizophrenia were examined intensively the study concentrated especially on the differences associated with chronicity vs hospital release the following 12 factors were significantly related to chronicity 1 psychotic or schizoid pathology in the mothering person 2 no se  paration of any kind from the pathogenic families 3 pre illness history of poor so  cial and sexual adjustment 4 failure to continue in treatment during childhood for at least 3 mth 5 less acting out in the community 6 neither disorientation nor confusion on admission 7 no symptoms of depressive psychosis 8 premor  bid schizoid personality 9 no clear precipitating events 10 no concern with dying during the acute phase of the illness 11 length of onset over 6 mth and 12 schi  zophrenic reaction in patients heredity items 1 2 and 5 were derived from early life history data and are thought to be new to the literature of prognosis in schizo  phrenia the remaining 8 factors can be scored from hospital data alone and have been cited in previous prognostic studies
MED	4854 on the formation of object relations and identifications of the kibbutz child some of the issues relevant to the early stages of object relation formation and identification of kibbutz children are discussed for this purpose the child rearing milieu of the kibbutz child is described and some clinical illustrations are given the relationship to the mother is seen as the main object relation and those to the educators as transient interchangeable need satisfying relationships on the basis of retrospective analytical material it appears that in the course of development the two relations as well as the two respective originally distinct object represen  tations are synthetised into one the conditions of communal education character  ised by double object relation formation from birth on are seen as factors that in  tensify the normative crisis of infancy especially the transition from the symbio  tic to the separation individuation stage of object relation development
MED	4846 the meaning of crying the multiple meanings of crying are reviewed and in particular stress is laid on tears as a response to some type of separation loss
MED	2953 the death of a parent in the case of depressive illnesses the death of either parent prior to the child reach  ing the age of 15 seemed to be correlated as a significant contributory factor with this exception statistical studies suggest that it is the death of a mother in the first 7 yr of a childs life as opposed to that of a father that is potentially an etiologi  cal factor for the future development of psychoses delinquency and psychoneuroses the case histories of 6 boys who had lost their fathers were given in each instance there was distinct evidence that the psychological symptoms and behavioral disturb  ances were to be attributed in large measure to the effect of the death upon the child and that in some cases the symptom choice was to be correlated with specific cir  cumstances surrounding the death of the father in some cases it was the unresolved grief reaction in the mother which helped to perpetuate the disorder in the child re  solution of this in the mother during therapy led to improvement in the childs func  tioning in other instances improvement occurred especially when the child ceased to be preoccupied with a close identification with the dead father those boys who were involved most closely in their mothers grief reactions were the ones who were most disturbed the brief treatment given these boys and their mothers appeared to be responsible for the considerable amelioration of symptoms that resulted ther  apeutic intervention is worthwhile especially in those instances where there is an unresolved grief reaction in the mother
MED	1848 the childs concept of death in this translation of a paper which first appeared in 1912 it is shown according to freud how far a childs appreciation of being dead differs from its true signifi  cance death means a reversible decrease in life functions that can be interrupted at any time like sleep at other times it may mean a temporary separation but always it is in mans power to change it in this concept the childs unconscious finds license for his sadism cruelty to animals and death wishes against persons close to him appear in overcompensation as exaggerated pity for dead creatures and the belief in mans power over life and death
MED	1849 mother child interaction during separation individuation after a stage of normal autism during the 1st weeks of extrauterine life the infant passes into a symbiotic phase gradually emerging from this stage of dual unity at the end of the 5th mth and during the 6th mth just before this the next phase separation individuation begins four characteristic subphases of this separation individuation process are described differentiation the practicing period association and a stage characterized by unfolding of complex cognitive functions the relation of mother and child throughout these subphases are studied and illustrated by clinical material a poor relation between mother and child in 1 subphase does not necessarily or usually preclude impressive changes for the better in the next subphase
MED	2736 the emotional needs of children in hospital hospitalization of a child for physical reasons brings with it separation from pa  rents siblings and familiar surroundings as well as the probability of subjection to frightening and painful procedures unless steps are taken to prevent or modify the resultant stress behavioral disturbances may arise and may result in per  manent damage to the developing personality
MED	2906 early childhood separations every child in this long term study of child rearing showed significant reactions to ordinary separations by about 1 yr of age the similar pattern of response in this group of children suggests a biologically determined cause the clinging reaction appeared when the child became mobile and able to move away from his mother re  gardless of the frequency or duration of his separations the majority of the mothers did not understand this natural phenomenon and regarded the clinging and crying of the 1 year old as evidence of spoiled or regressed behavior the pediatrician can be helpful to a mother by anticipating and explaining separation responses by indi  cating their universality and by giving specific recommendations for gradual changes to modify these reactions
MED	9787 changes in developmental quotient under two conditions of maternal separation developmental scales were administered to 2 groups of infants during and sub  sequent to a temporary period of institutionalization although both groups experienced maternal separa  tion only 1 group was subjected to deprivation in that it received very much less stimulation than the other results from a longitudinal testing program show that the scores of the deprived group during the period of separation were significantly lower than those of the nondeprived group no progressive de  terioration of scores took place in the course of institutionalization immediately following return home while the scores of the nondeprived group re  mained constant those of the deprived infants jumped to the level of the other group 3 theories regarding the mechanism underlying the association between deprivation and developmental retardation are exam  ined and it is suggested that an explanation in moti  vational terms best fits the results obtained
MED	1808 separation anxiety a factor in the object relations of schizophrenic patients the thesis is advanced that special vulnerability to separation anxiety is a crucial factor in the schizophrenics difficulty in establishing and maintaining satisfactory interpersonal relationships 2 major reasons for this are lack of autonomy and lack of object constancy without a stable autonomous capacity for self regulation and adaptation he is inordi  nately dependent upon others for help protection and direction without object constancy he is unable to maintain a stable representation of the needed person in the latters absence evidence is presented from the intensive psychotherapy of schizophrenic patients many of the vicissitudes of the doctor patient relation  ship center about the patients separation anxiety and his attempted defenses against it these include clinging perceptual and cognitive distortions designed to deny separation and recourse to substitute objects promi  nent in many of these efforts is the attempt to reverse passive victimization into active mastery the practical implications of this thesis for the treatment of schiz  ophrenic patients are discussed
MED	9101 separation experiences and health records in a group of normal adults about 25 of 455 ostensibly normal ss reported a recent separation experience as defined in this study the frequency of visits to the dis  pensary for symptomatic complaints was not signifi  cantly higher among those who reported separation than among those who did not the data suggest that an apparent association between relatively high cornell medical index score and history of separation experience may be understandable in terms of a cause  effect relationship between separation experience and illness
MED	11306 separation and attempted suicide of 3 groups of psychiatric patients at  tempted suicides those with suicidal urges and non  suicides there were significantly more attempted suicides among patients with a history of childhood and antecedent separation than controls in childhood the significant difference was found primarily in the period from birth to 7 yr there was no significant interaction between childhood and antecendent separation and suicide attempt or suicide urge
MED	1463 investigations of lens protein and microelectrophoresis of hydrosoluble protein in senile cataract the investigations on lens protein and on agar microelectrophoresis of hydro  soluble protein in normal lenses and in those affected with senile cataract re  vealed the following facts 1 in opaque lenses a diminution of the total protein and the soluble protein takes place as well as an increase in the amount of in  soluble protein the decrease in the quantity of soluble protein is higher than the increase of insoluble protein which does not only point to a transformation of the soluble protein into the insoluble variety but also to the disappearance of a protein fraction from the lens changes in the quantity of soluble protein are accompanied by the decrease of protein in slow fractions of the electropherogram and even by the disappearance of these fractions and the increase of the amount of protein in fractions of medium velocity with the development of cataract and the mature phase of cataract all these processes become more and more distinct in this respect a strong parallelism exists between the protein changes and the clinical picture of senile cataract 2 qualitative and quantitative changes which occur in the protein of normal lenses with advancing age show a character similar to those in senile cataract however they are less pronounced in this instance the de  crease in the quantity of soluble protein is likewise closely associated with the diminution of the protein content in the slow fractions of the electropherogram 3 the changes in the soluble protein content of the lens and the alterations of the protein amounts in the slow fractions which always accompany the former play the principal role in the aging process of the lens and in the development of senile cataract 4 the investigations seem to indicate that the aging processes of lenses as well as the development of senile cataract are of a similar character but of different intensity 5 undoubtedly the processes of transition from slow fractions of soluble protein into faster ones and the transformation of part of the soluble protein into insoluble protein which is likely to be associated with these processes as well as the partial disappearance of total protein from the lens seem to play a very important part in the mechanisms pertaining to the development of cataract
MED	1949 studies on the soluble proteins of bovine lens immuno  chemical analyses of protein fractions the lyophilized soluble lens proteins were dissolved in 0 005 m phosphate buffer at ph 6 8 and the solution was subjected to column chromatography on deae die  thylamino ethyl cellulose elution was accomplished by changing the ph and ionic strength of the eluting buffer the components were fractionated by stepwise elu  tion the lens proteins were separated into 17 fractions by column chromatogra  phy these fractions were compared with a b and y crystallines for electrophore  tic mobility and the antigenic purity of each fraction was examined immunochemi  cally the results showed that while the fractions were not completely pure they were purer than the a b and y crystalline fractions and that f 1 a b c and d corresponded to y crystalline while f 2 a b c d e and f corresponded to b crystalline and f 3 4 5 6 7 8 and 9 to a crystalline
MED	3107 studies on y crystallin from calf lens ii purification and some properties of the main protein components four proteins belonging to the y crystallin group were purified by chromatography on sulphoethyl sephadex and phosphate cellulose columns the proteins were homo  geneous in gel and immunoelectrophoresis experiments and could be crystallized their molecular weights n terminal amino acid sequences and antigenic structures were all similar but their amino acid compositions and the sulphydryl groups con  tained showed certain dissimilarities it is probable that the 4 proteins possess small differences in their primary structure which are not associated with the antigenic sites and which may have arisen from mutations during evolution
MED	3105 studies on the subunits of a crystallin and their recombi  nation earlier investigations have shown that in the presence of high concentrations of urea a crystallin from bovine lens is split into a number of subunits with apparent  ly different electrophoretic mobilities but similar molecular weights the recom  bination of these subunits after removal of the urea has been studied by ultracentri  fugation and immunoprecipitation techniques it was found that maximal recombina  tion was obtained when the ionic strength during the removal of the urea was high 0 2 whereas at low ionic strengths a molecule with only half the molecular weight of native a crystallin and a much lower sedimentation coefficient was obtained a complete recovery of the structure of native a crystallin was never obtained even at high ionic strengths as was evident from electrophoretic and quantitative preci  pitin analyses the subunits were fractionated by chromatography on deae cellu  lose in the presence of 7 m urea the purification was followed by polyacrylamide  gel electrophoresis after removal of the urea at high ionic strength 2 of the fractions obtained showed reactions of only partial identity with native a crystallin in immunodiffusion tests but all other fractions showed complete identity the differences in the electrophoretic mobilities of the fractions in the presence of urea persisted after removal of the urea all fractions had much higher sedimen  tation coefficients in the absence of urea than in its presence although the values for urea treated unfractionated a crystallin obtained after removal of the urea were not reached even at high ionic strengths the amino acid composition of the fractions was found to differ these observations suggest that a crystallin is com  posed of a number of chemically different but related subunits of approximately the same size which are bound together by nonspecific noncovalent bonds pos  sibly hydrophobic bonds moreover when isolated these subunits have the ability to associate and form molecules of high molecular weight
MED	3106 fractionation of b crystallin from calf lens by gel fil  tration b crystallin was isolated from calf lenses by a combination of gel filtration on sephadex g 75 and vertical column zone electrophoresis it was subdivided into 4 fractions by subsequent gel filtration on dextran gels with low cross linkage each fraction showed only 1 major peak in the ultracentrifuge the sedimentation coefficients of which were 13 6 9 6 4 9 and 4 2 s for fractions i iv respectively however all 4 fractions contained some additional minor components as revealed by sedimentation and immunoelectrophoretic analyses the fractionation procedure may be of value as a first step in the isolation of individual proteins of the b crystal  lin group
MED	195 properties of a cold precipitable protein fraction in the lens a soluble protein fraction which precipitates in aqueous solutions at temperatures below 10 c has been isolated from the rat lens this fraction appears to be re  sponsible for the reversible cold cataract which has been seen to develop when young mammals are exposed to temperatures below 10 c as the rat ages the concentration of this protein fraction decreases but the fraction does not com  pletely disappear even from the lenses of 3 year old rats although the molecular species comprising this fraction appear to be homogeneous in the ultracentrifuge disc electrophoresis and immunodiffusion have shown that they are a heterogeneous mixture of a  b  and y crystallin subunits the ability of the cold precipitable protein ccp fraction to precipitate in the cold depends upon its concentration and the ionic strength and ph of the solvent in solutions of ph 4 0 some aggregation of the 4 s cpp occurs to form a 17 s component which no longer precipitates in the cold the ability of this protein fraction to precipitate in the cold may depend on hydrophobic bonding and its influence on the conformation of the protein
MED	773 the effect of radiation on lenticular epithelial enzymes in young rabbits the mitochondrial fraction and the soluble fraction of the epithelial cells of the lens from 6 week old new zealand white male rabbits exposed to 800 r of whole head x irradiation were evaluated for glucose 6 phosphate dehydrogenase isocitrate dehydrogenase malate dehydrogenase glutathione reductase glyceraldehydephos  phate dehydrogenase purine nucleoside phosphorylase nadph2 diaphorase and nadh2 cytochrome c reductase activities increased enzyme activities were noted in the irradiated lenticular tissues for purine nucleoside phosphorylase nadph2 diaphorase and nadh2 cytochrome c reductase decreased activities for glucose 6 phosphate dehydrogenase malate dehydrogenase glutathione reductase and gly  ceraldehydephosphate dehydrogenase were observed in the lenticular tissues of ir  radiated animals the activity of isocitrate dehydrogenase was the same in the ir  radiated and in the control animals
MED	465 conversion of a crystallin of bovine lens into insoluble protein in vitro a crystallin can be converted into an insoluble form by treatment with alloxan and to a very small extent with iodoacetate other reagents such as hcl naoh reduced glutathione hydrogen peroxide mercaptoethanol were not able to convert a crys  tallin into an insoluble form the alloxan treated insoluble a crystallin could be made soluble by treatment with 7 m urea the product thus made soluble had the same electrophoretic mobility as a crystallin but showed cross reaction with a crystallin in ouchterlony plate and did not have proteolytic activity alloxan was effective in producing cataract of rabbit lens when very small amounts were injected into the aqueous
MED	1972 structural studies of a crystallin a crystallin has been isolated from the cortex of ox lens by isoelectric precipitation followed by chromatography on deae cellulose the amino acid composition is in agreement with that reported for a crystallin prepared by a different method there is one thiol group 20 000g of protein 20 000 is the order of magnitude of the sub  unit molecular weight and disulphide bonds are absent the thiol group has been alkylated with radioactive iodoacetate in the presence of urea partial acid hydroly  sis of the alkylated protein gives according to the conditions mainly 3 radioactive peptides or nearly exclusively one radioactive dipeptide the dipeptide is n seryl  s carboxymethyl cysteine ser cmcys the 2 other peptides are probably the tri  peptides related to ser cmcys the simplest interpretation of these results is that the sequence around the cysteine residue is a common structural feature of the sub  units of a crystallin
MED	1751 on the subunits of a crystallin a crystallin was isolated from total water soluble lens extract by preparative zone electrophoresis on starch or pevikon c870 blocks and purified by density gradient centrifugation and sephadex chromatography these preparations were treated with urea or sodium dodecyl sulphate and submitted to electrophoresis on polyacrylamide gels containing either urea or sodium dodecyl sulphate whereas in 7 m urea a large number of zones was detected only three bands were observed in 1 sodium dodecyl sulphate on the other hand the sedimentation coefficient had the same value in both media the authors re investigated the n terminal amino acid content in the starch block preparations and compared the result with that obtained from the preparations isolated according to their new procedure the concentration of dinitrophenyl glutamic acid was lower in the purified samples urea treated samples had the same concentration of n terminal glutamic acid whereas the concentration of the trace end groups did not change sedimentation diffusion equilibrium in the analytical ultracentrifuge revealed a slight heterogeneity in the purified samples electron micrographs of electrophoretic and of further purified samples were very similar at neutral or slightly alkaline ph they showed almost uniform spherical aggregates in which a substructure was observed at acid ph coiled filaments rather than small globules could be demonstrated
MED	1752 separation of the soluble proteins of bovine lenses on polyacrylamide gels the soluble proteins of bovine lenses were separated by gel filtration on polyacryl  amide gels the presence of ethylenediaminetetra  acetate in the buffer was found to be essential for achieving a good separation of the lens homogenate into four fractions   a b c and d ultracentrifugal electrophoretic and immunochemical analyses were used to compare these fractions with the soluble crystallin fractions of the lens fraction a was compared with a crystallin fractions b and c with b crystallin and fraction d with y crystallin the distribution of these four protein fractions in the nuclear and cortical parts of calf and cow lenses was determined the oxidation sensitive protein fraction of the calf lenses was separated from fraction b on an se sephadex column
MED	1745 the deaggregation of bovine lens a crystallin sedimentation equilibrium studies of lens a crystallin at neutral ph indicate that this material is composed of a number of different sized species a study of the effect of alkali upon a crystallin indicates a progressive deaggregation of the ma  terial with increasing ph sedimentation equilibrium studies were performed at ph 12 8 as well as in guanidine hydrochloride 7 m urea and with succinylated material under all of these conditions a molecular heterogeneity was observed the data indicate that independent species coexisted under most dissociating conditions the weight average molecular weights of the succinylated and of the alkali  urea  and guanidine hydrochloride treated material were found to have an integral relation  ship of 8 4 2 1 respectively since a constant ratio of m2 mw was found it was concluded that the same spread of distribution of molecular species occurred for each of the deaggregating conditions the results in guanidine hydrochloride could not be evaluated in this manner because of a small concentration dependence these conclusions imply that not only the weight average molecular weight in 7 m urea but the actual molecular weight of each individual species in urea was one half of the value to be found in alkali and one quarter that of the succinylated material
MED	1747 the problem of albuminoid albuminoid is the main constituent of the insoluble fraction of the lens proteins albuminoid from the cortex of ox lens has been fractionated on deae cellulose in 7 m urea peptide maps of the fractions are very similar to those from the corre  sponding fractions from a crystallin albuminoid can be regarded as an insoluble a crystallin an undiluted ground lens is clear but becomes turbid on dilution if albuminoid is present in the normal lens it does not cause turbidity even when the cellular structure is disrupted it is perhaps more likely that the albuminoid is formed on dilution of the lens mush the high concentration of proteins in the lens especially in the nucleus entails a high degree of order which will be destroyed on dilution this phenomenon may well be connected with the precipitation of the albuminoid
MED	787 further autoradiographic studies of the lens epithelium normal and x irradiated rat eyes cell proliferation and migration in the lens epithelium of normal and x irradiated rat eyes were studied by means of autoradiography after labelling with tritiated thymidine cells of the normal lens epithelium require 16 hr to pass from the beginning of the synthesizing period to the completion of mitosis this interval is partitioned as follows s period approximately 10 hr g2 slightly less than 5 hr and mitosis 72 min following division labelled daughter cells migrate from the germinative zone to the postequatorial rows and by 2 weeks after tracer injection many radioactive nuclei are found in the lens bow epithelial cells irradiated while in the dna synthesis phase undergo degeneration beginning approximately 8 hr after exposure the onset of cell death corresponds to the time at which these cells would normally be preparing for mitosis indicating that they die in abortive divisions a small percentage of the originally labelled cells survived until 3 days after irradi  ation but by 2 weeks this number fell almost to zero the loss of radioactive cells occurred most rapidly in the equatorial zone
MED	2627 chicken lens development epithelial cell production and migration in the earliest stages of chicken lens development cell division occurred over the entire lens cell division first stopped in the posterior side of the lens vesicle as the cells differentiated into primary lens fibers after the annular pad developed cell division occurred for the most part in the anterior surface epithelial cells shortly after hatching and thereafter a germinative zone consisting of a narrow band of epithelial cells adjacent to the annular pad developed the cells from the germinative zone migrated slowly and differentiated first into annular pad cells and then into lens cortex fibers over an estimated 2 year period this slow migration of cells in the lens is discussed in relation to the failure of the adult chicken to de  velop radiation cataracts
MED	1494 selenium content of fish flour in relation to kwashiorkor and dental caries the fact that fish flour was shown to be a rich source of dietary selenium 169 p p m may have important implications i e deleterious effect on teeth in the treatment and prevention of protein malnutrition it indicates that some disease syndromes in man may be a manifestation of selenium deficiency it is recommended that the role played by selenium in protein malnutrition should be given serious consideration by research workers
MED	2192 selenium content of fresh eggs during a study of effects of traces of se on dental caries the authors determined this element in eggs whole egg contains appreciable amounts of se this is found chiefly in the yolk mean value 0 324 0 039 p p m with only 0 051 0 029 p p m in the white
MED	1541 selenium content of human milk possible effect on dental caries selenium appears to be a factor capable of increasing susceptibility to dental caries in children and rats in an area considered to be nonseleniferous milk collected from 15 mothers 17 44 yr old of low socio economic class had a mean selenium content of 0 021 p p m standard error 0 003
MED	1577 mode of action of selenium in relation to biological activity of tocopherols dietary selenium at levels below 1 ppm has a partially beneficial effect upon nutritional muscular dystrophy but is ineffective or detrimental at higher levels the role of selenium in improving the effectiveness of vitamin e is due at least in part to the fact that dietary selenium increases the retention of the a tocopherols especially d a tocopherol this has been shown by chemical determination of plasma tocopherols and also by tracing the activities of tritiated tocopherols and selenium75 in serum and in various fractions of serum proteins in chicks receiving these nutrients alone and in combination se75 and h3 a tocopherol activities followed each other very closely in the serum proteins these studies indicated that vitamin e may be carried by a selenolipoprotein fraction associated with serum y globulin thus one biological role of selenium appears to lie in a selenium containing compound which acts as a carrier of vitamin e and which may function in absorption retention prevention of destruction and perhaps transfer across cell membranes of d a tocopherol thereby enhancing its biological activity in the blood and perhaps in cells throughout the body
MED	3123 effect of sodium selenate on acute poisoning with thallium experiments were performed on wistar rats weighing 150 200 g thallium was ad  ministered s c in doses of 20 mg kg and 30 mg kg sodium selenate was given per os in doses of 10 mg kg 2 hr after poisoning and 5 mg kg daily for the next 2 days results indicate that sodium selenate protects the animals from death it binds the thallium ions and increases their deposition in organs comparison of the level of thallium in organs of treated rats shows that selenate increases in liver by 290 6 in kidneys by 326 8 and in bones by 210 0 no influence of selenate on excretion of thallium in the urine was found but fecal excretion of thallium increased by an average of 45 of the treated animals
MED	2281 inhibition of active transport of sugars through rat intestine in vitro ii action of mepacrine atractyloside and selenite it is shown that mepacrine atractyloside and selenite which had been regarded as inhibitors of intestinal absorption of glucose are inhibitors of active transport of sugars in sacs of everted jejunum of rat wilson and wisemans method mepacrine 5 x 10  3 m and 10  2 m inhibit by 85 and 100 respectively the active transport of galactose with atractyloside 10  5 m and 10  3 m the inhibitions were 77 and 100 and with selenite 10  4 m and 10  3 m about 70 in general the inhibitors are effective within orders of magnitude which are similar in vivo and in vitro atractyloside is rather more effective in vitro than in vivo and mepacrine rather less it is easier to achieve total inhibitions of the active transport of sugars in vitro than of intestinal absorption from isotonic solutions in vivo
MED	2284 analogs parasympathetic neuroeffectors ii comparative pharmacological studies of acetylcholine its thio and seleno analogs and their hydrolysis products acetylthiocholine and acetylselenocholine exert acetylcholine like effects on the guinea pig ileum and frog rectus abdominis preparations with the latter preparation responses to acetylthiocholine and acetylselenocholine in contrast to that to acetylcholine are not enhanced by the addition of an anticholinesterase this is attributable to the relatively high activity of the hydrolysis products cholinethiol and cholineselenol acetylthiocholine and acetyselenocholine undergo enzymatic hydrolysis at approximately the same rate as does acetylcholine the hydrolysis products of acetylthiocholine and acetylselenocholine which have effects on the guinea pig ileum comparable to those of the parent esters are readily oxidized in air to the relatively inactive choline disulfide and choline diselenide respectively these observations are helpful in explaining many of the apparently contradictory statements in the literature regarding the actions of acetylthiocholine
MED	3604 cytotoxicity of organophosphorus compounds comparative activities of trimethyl derivatives of thiophosphoric and selenophosphoric acids on vegetable pisum root and human hela cells of the 4 compounds studied the seleno compounds were more cytotoxic for hela cells than their thio analogues whereas the activities on pisum root cells were equal the parent phosphoric acid derivatives have a wider activity range on hela cells than the seleno and thio derivatives further studies are in progress
MED	3640 poisoning with sodium selenite chronic poisoning with na selenite in the drinking water causes hepatic cirrhosis usually of atrophic type in rats in rabbits there seems to be a definite diabetogenic action while attempts to demonstrate such action in dogs have so far given inconclusive results the difference between these 2 species is perhaps due to the technique used different spacing of injections for practical reasons the action of selenite on the pancreas is discussed and it is pointed out that se can replace s in sh groups thus rendering the latter ineffective both in effects on the liver and in those on the pancreas se seems to resemble alloxan
MED	2552 the tissue distribution of se75  selenouracil and se75  selenourea when selenium analogues of thiouracil and thiourea labelled with se75 were injected into rabbits high radioactivity appeared in lung liver and kidney the animals lungs could be visualised by photoscanning but quality was poor and neither compound is recommended for trial for lung or adrenal scanning in man
MED	1142 sodium selenate toxicosis pathology and pathogenesis of sodium selenate toxicosis in sheep the pathogenesis of selenium toxicosis was studied in 30 ewes fed subtoxic to toxic levels of sodium selenate for 1 to 5 mth seventeen of the 30 died of selenium toxicosis the most severe and consistent pathologic changes were found in the myocardium and lungs myocardial alterations were focal to diffuse degeneration necrosis and early replacement fibrosis pulmonary changes consisting of edema and interstitial hemorrhages were typical of the degenerative processes which characterize passive congestion of the lungs resulting from left ventricular insufficiency atrophy of lymphoid centers in the spleen and lymph nodes was common degenerative changes were occasionally found in liver kidneys and gastrointestinal tract
MED	1143 sodium selenate toxicosis the distribution of selenium within the body after prolonged feeding of toxic quantities of sodium selenate to sheep the distribution of selenium in the body tissues of adult sheep fed subtoxic to toxic quantities of sodium selenate daily for 1 to 5 mth varied with the tissue type and with the level and duration of selenium consumption selenium concentration was highest in the liver followed by in descending order the kidneys lungs spleen myocardium skeletal muscles and brain
MED	1172 studies on selenium toxicity and chondroitin sulfate and taurine biosynthesis in the chick embryo fourteen day old chick embryos were used in in vivo experiments a toxic selenite treatment did not cause a reduction in the extent of sulfate s incorporation into chondroitin sulfate or into taurine or a reduction in the observed tissue levels of these metabolites rather the taurine level was significantly greater with the embryos which received selenium the extent of the incorporation of selenite se into the metabolites was low or not significant
MED	843 reactions of seleno  and sulfoamino acids with hydroperoxides reactions of methionine cystine and their selenium analogues with hydrogen peroxide and organic peroxides have been studied methionine reacts most rapidly with hydrogen peroxide but selenocystine causes the most decomposition both react much more slowly with organic peroxides the results suggest that selenocystine may act as a biological antioxidant
MED	2127 selenium toxicity in domestic animals the article with an extensive bibliography is a compendium of available information on selenium toxicity in domestic animals literature reveals evidence of organically bound se being more biologically active when given orally to domestic animals than inorganic se salts there is also variation in toxicity of organic se analogs when exposed to ruminal digestion there is considerable reduction of se salts to the relatively biologically inactive elemental se which may result in fecal excretion of se as such to as much as 40 of a single oral dose fluorine molybdenum chromium vanadium cadmium zinc cobalt nickel and uranium increase se toxicity arsenic and tungsten give some protection against it bromobenzene benzene and napthalene mobilize tissue se and stimulate its excretion since se preparations designed for topical application in treatment of skin disease have been available for use in both man and dogs the literature has reported cases of poisoning from misuse of such preparations selenium properly used can be a valuable therapeutic agent though certain salts of se must be regarded as potentially toxic however there is considerable latitude between therapeutic and or nutritional and toxic doses of these salts
MED	1845 further studies on specific transplantation antigens in rous sarcoma of mice mice allografted with different sarcomas induced by the schmidt ruppin variant of rous sarcoma virus rsv sr showed a resistance against subsequent isografting of 9 different rous sarcomas transplantation resistance could also be induced by rous mouse tumor cells x irradiated with 8000 r or with cell free tumor extracts containing no demonstrable virus no transplantation resistance could be demon  strated after allograft pretreatment with various polyoma tumors or non viral tu  mors allograft pretreatment with rous tumors induced no demonstrable resistance against isografting of polyoma tumors inoculation of rsv sr or rous chicken sar  coma suspension into adult mice gave no clear cut resistance against isograft  ing of mouse sarcomas neither after allografting of rous tumors nor after virus or chicken sarcoma inoculation into adult mice could virus neutralizing activity be demonstrated in the sera the results demonstrate the presence of common speci  fic transplantation antigen s in different rous sarcomas in mice and speak against an identity between the transplantation antigen s and viral antigen s
MED	1846 anaphylactic tests in model tumour antigen investigations the efficacy of anaphylactic tests in detecting tumor antigen in serum was investi  gated a simple model of a tumor antigen study was carried out using rat tissue and rat serum with bovine y globulin byg acting as a mock cancer antigen it was found that if byg absolute dosage 100 ug had formed 1 6 of the antigen mix  ture used for sensitization it was readily detected when present in a concentration of 10 3 in the serum used for challenge but not invariably detected in a concentra  tion of 10 4 if byg absolute dosage 50 ug had formed approximately 1 50 of the sensitizing mixture it was infrequently detected even when present in the challeng  ing serum in a concentration of 10 2 it is concluded that anaphylactic tests used in this context do not have a very high sensitivity or discriminatory capacity
MED	1066 the effect of lymphoid cells from the lymph of specifically immunised sheep on the growth of primary sarcomata in rats the growth of primary fibrosarcomata induced in rats with 3 4 benzpyrene was retarded by the injection of lymphocytes obtained from the efferent duct of a lymph node in a sheep immunized with a piece of the tumor to be treated the action of the heterologous lym  phocytes was specific to the particular tumor used for immunization suggesting that reaction against tumor  specific antigens is involved the cells responsible are believed to be medium sized pyroninophilic lymphocytes which may stimulate the immune system of the host to react against the autochthonous tumor
MED	2570 treatment of canine neoplasms with autogenous vaccinial preparations inbred mice with transplantable sarcoma and carcinoma were treated with im  plants of their tumours which had been grown in strains of mice normally resistant to the tumours complete regression of transplantable tumours was noted in 22 of the treated mice and 78 had life spans double that of untreated controls one dog with spontaneous scirrhous mammary carcinoma and another with lymphosarcoma were treated with implants of their own tumours after growth in cortisone treated mice regression of the spontaneous neoplasms followed in both cases it is suggested that growth of a neoplasm in a foreign host alters the mole  cular structure of the neoplasm making it antigenic when returned to the original host antigens produced are also effective against the original lesions
MED	744 studies on protein and nucleic acid metabolism in virus in  fected mammalian cells the formation of a virus specific antigen in krebs ii ascites tumour cells infected with ence  phalomyocarditis virus krebs ii mouse ascites tumor cells infected with encephalomyocarditis virus were found to contain in addition to mature virus a virus specific protein antigen an assay based on the ability of this antigen to block the neutralization of purified virus by its specific antiserum was developed this antigen was present both in the cul  ture fluid 17 hr after the infection of cells with virus and intracellularly where its titer increased at a time when viral capsid protein was being synthesized within the cell it was mostly localized in the soluble cell sap in contrast with virus the anti  gen did not agglutinate sheep erythrocytes and its immunological properties were destroyed by digestion with trypsin ribonucleic acid was not detected in concentrat  ed preparations of the antigen nor was the titer of antigen affected by ribonuclease the antigen had a sedimentation coefficient 20 of approx 14s and its diffusion co  efficient determined by the method of allison and humphrey 1960 was 3 2 x 10 7 sq cm sec  1 the particle weight of the antigen was hence 420 000 40 000 the capsid protein from purified encephalomyocarditis virus could be degraded by treat  ment with ethanolamine into a protein of sedimentation coefficient 20 of approx 4s the 14s antigen when similarly treated yielded a protein of similar size however no such smaller antigen was detected in virus infected cells it is concluded that the non hemagglutinating antigen represents a polymeric form of the basic viral capsid  protein molecule and that it is synthesized in the cytoplasm of infected cells it may be either an intermediate or a by product in the process of viral capsid protein syn  thesis
MED	1368 immunologic competence and induction of neoplasms by polyoma virus thymectomy at 3 days of age in several inbred strains of mice and in an f1 hybrid resulted in a strikingly increased frequency of neoplasms following infection with polyoma virus age susceptibility was extended to at least 30 days of age in highly resistant c57bl mice the usual stigmata associated with thymectomy at birth were not found in the 3 day thymectomized mice nonetheless the methods used to restore immunologically deficient thymectomized neonates were also effective in restoring the capacity to resist polyoma virus tumor induction adult syngeneic spleen cells thymus tissue in millipore diffusion chambers and syngeneic thymus grafts growth curves of polyoma virus in kidney salivary glands and liver were quite similar in thymectomized and intact litter mates hemagglutination inhibition antibodies deter  mined periodically up to 30 days after infection were also similar in both groups these results are discussed in terms of a concept involving virus specific tumor antigens and the immunologic status of the animal
MED	1848 antigen analysis of sera from patients with malignant tumors by immunodiffusion methods immunoelectrophoresis and ouchterlonys method were used for the antigen analy  sis of sera from 320 cancer patients 250 normal or non tumorous cases served as controls immunoelectrophoresis showed abnormal precipitin lines which could not be demonstrated in normal sera most of the abnormal antigens were demonstrated in the a2  and b1 globulin fractions the distribution of these antigens differed in individual cases and was not related to the histopathological classification and site of the tumors however these antigens increased in parallel with growth of the tumors and disappeared or markedly decreased after surgical removal of the tumor tissue almost all sera of patients with myeloma leukemia and malignant lymph  oma formed one characteristic line in the b2 globulin region and they could be dif  ferentiated from the patterns in cases of carcinoma
MED	2354 isoantigenic properties of tumors transgressing histocompatibility barriers of the h 2 system sublines capable of transgressing h 2 histocompatibility barriers have been derived from strictly strain specific tumors by 1 passage through newborn hosts of a foreign genotype 2 passage through adult h 2 incompatible recipients pretreated with isoantisera directed against the tumor cells the nonspecific character induced by these procedures was usually expressed in a number of different h 2 incompa  tible recipients the changes responsible for the conversion to nonspecific growth appeared to proceed in a stepwise fashion expression of the nonspecific character required exposure to the foreign host environment for more than 30 days at this stage and during the subsequent 3 transfer generations reversion to strain specific growth occurred on back transfer to the strain of origin after 4 passages in the foreign hosts the nonspecific character was permanently established however and could not be reverted by prolonged passage in the original host genotype the growth rate of strain specific tumors and their nonspecific sublines was compared in the strain of origin no difference was found with one tumor while the strain  specific line grew better than the nonspecific sublines with another this difference was detected in the homozygous strain of origin and in different semi isologous f1 hybrids all lines grew better in the homozygous strain than in the f1 hybrids however a comparison was made between the concentration of h 2 isoantigenic surface determinants in strain specific tumors and their nonspecific sublines by a quantitative absorption technique in vitro all nonspecific sublines had a lower concentration of h 2 isoantigens than the strain specific tumors this suggests that nonspecific tumors develop as a result of immunoselection of variants resistant to the homograft reaction and are characterized by a lowered concentration of h 2 antigens
MED	2371 participation of 7s and 19s antibodies in enhancement and resistance to methylcholanthrene induced tumours serum factors responsible for enhancement and resistance to methylcholanthrene  induced tumors in a syngeneic system in mice were studied they were found to be part of the serum immunoglobulin system the active components of specific anti  tumor serum were always contained in the 7s y 2 and 19s y 1m fraction while no activity was detected in the 4s fraction in sera which in the given dose enhanced growth of the tumor graft enhancing activity was present in both the 7s and 19s fraction of the serum and was higher in the former in sera which in the given dose influenced the interaction of the organism with the tumor by producing resistance to the tumor graft both fractions were again active the activity of fraction 19s being higher than that of fraction 7s
MED	2372 the effect of immunity against sex antigen on a tumour graft containing sex antigen the tumor bp 1 induced by benzpyrene in c57bl male mice contains sex antigen sex antigen is not lost during growth of tumor against immunity directed against this antigen the tumor however becomes more resistant to immunity and the content of sex antigen is decreased
MED	2373 factors influencing the induction of enhancement and re  sistance to methylcholanthrene induced tumours in a syn  geneic system active immunological enhancement of the growth of methylcholanthrene induced tu  mors was demonstrated in a syngeneic system in mice enhancement was detected 3 5 wk after preimmunization with irradiated tumor suspension and was succeeded after the 6th wk by the development of resistance to the tumor analysis by means of adoptive and passive transfer showed these to be true immunological phenomena enhancement and resistance were transferred by serum and by the lymph node cells of preimmunized mice threshold doses of tumor cells were found to be the most satisfactory for the detection of resistance and enhancement in this system
MED	5512 antigenic properties of human tumours preliminary studies on the antigenic properties of human tumours have been carried out using heterologous antisera prepared in rabbits against a number of different cancerous and normal tissues after repeated absorptions antisera were obtained which reacted only with tissue antigens some antisera after ab  sorption with normal tissues reacted only with tumours seventy two tumour and 31 normal tissue extracts were studied by means of the ouchterlony agar gel double diffusion technique the results showed the presence of an antigen or antigens in some human malignant tumours which were not detectable in normal tissues in foetal tissues or in hela cells in addition there was some loss of normal tissue antigens from tumours attempts are being made to isolate and characterize these tumour and normal tissue antigens
MED	5514 the incorporation of sv40 genetic material into adenovirus 7 as measured by intranuclear synthesis of sv40 tumor antigen the l l strain of adenovirus 7 free of detectable infectious sv40 virus induced sv40 tumour antigen demonstrable by fluorescent antibody staining in green mon  key kidney rabbit kidney hamster embryo and human embryo kidney cell cultures in green monkey and human cell cultures there was a cytopathic effect and more cells contained the sv40 tumour antigen than in the other types of culture adenovirus 7 viral antiserum neutralized the sv40 tumour antigen inducing ability of the l l strain virus but anti sv40 monkey serum and serum from sv40 tumour bearing hamsters did not an adenovirus 7 preparation propagated exclusively in human tissue did not induce the sv40 tumour antigen the sv40 tumour antigen was entirely localised within the cell nuclei and appeared to be transmitted to daughter cells during mitosis
MED	264 fluorescent antibodies to human cancer specific dna and nuclear proteins specific antigens have been demonstrated in certain cancers in this study they were obtained from an adenocarcinoma of the colon and an ewings sarcoma homogenates were prepared and male rabbits were immunized the animals were bled to death 10 days after the last injection testing included fluorescent antibody methods and agar gel horizontal double diffusion precipitin test the pattern of reaction of these antibodies against various cancers seems to be dependent upon the source of the cancerous dna bound proteins and the salt concentration used in their isolation human cancer specific cross nuclear antigens seem to be cross reacting rather than identical in structure the cancer specific antibodies could be removed only with absorption of the immune globulins with cancerous tissues salt soluble human dna bound proteins from an adenocarcinoma of the colon and an ewings sarcoma induced the formation of cancer specific antibodies which showed positive fta re  actions to a maximum titer of 1 128 against 95 of the cancerous tissues studied these cancer specific antibodies gave similar fta reactions with cell nuclei of normal appearing liver parenchyma adjacent to metastatic carcinoma of colon nor  mal appearing colon near to metastatic carcinoma of the colon normal appearing colon near to carcinoma of the colon and a long standing case of chronic ulcerative colitis evidence is shown that this finding possibly may represent a serological detection of an early or latent cancerous change in morphologically normal cells these cancer specific antigens have been identified as rounded intranuclear dna  bodies and nuclear proteins which can be specifically destroyed by dnase trypsin
MED	266 immunology of the cancer cell tumour specific antigens after a broad historical survey of immunological studies of cancer a review is given of the evidence showing that antigens present in normal cells are missing from the malignant cells that arise from the same tissue this evidence is considered in con  junction with the deletion hypothesis of carcinogenesis and the author emphasizes that in his view the key event in carcinogenesis is enzymatic deletion antigenic gain and intensification in the course of spontaneous chemical and viral carcino  genesis is reviewed together with experiments demonstrating the existence of tumour specific antigens the question is then posed if tumours have specific anti  gens why is evidence for their rejection so scanty the occasional spontaneous re  gression points to host resistance but its rarity suggests that tolerance generally develops consideration is given to the application of immunological methods to therapy and although current achievement in this field is limited new immunological stratagems might yet transform the picture finally a plea is made for the integra  tion of the disciplines of immunology and cellular differentiation the prospect is raised that through a synthetic and holistic approach we might discover the suscepti  bility of the cancer cell to re differentiation and re recognition
MED	effets de la carence potassique chez le rat sur le squelette le cholesterol plasmatique lhistologie des surrenales r habib j lefebvre et p royer potassium deficiency in the male rat at the time of weaning provokes an increase in the weight of the suprarenals an atrophy of the glomerular zone and a lipoid hypertrophy of the fasciculae it causes a rise in the level of the blood cholesterol it reduces the phosphate level in the blood and increases the phosphate in the urine the blood calcium level is not altered but a hypocalciuria is noted it leads to a severe osteopathy which has been investigated by radiography microradiography and histological and bio  chemical study of the skeleton the following are the charac  teristics arrest of osseous growth delay of maturation arrest of chondrogenesis formation of dense metaphyseal lines or lines of arrest osteoporosis these facts are discussed and compared to the analogous changes found in the syndrome of chronic idiopathic hypo  kalaemia with hyperkaluria in the infant
MED	vergleichende renale phosphatelearance untersuchungen beim hyperparathyreoidismus und beim sog phosphatdiabetes the analysis of the function of the kidneys give a contribution to the pathophysiology of two different diseases of general osteopathies whose pathogenesis or etiology are still not clear in some points the phosphate clearance pre  and postoperative in one patient with hyper  parathyroidism showed that after the removal of the adenoma of the parathyroid the renal reabsorption of phosphate improved only tempo  rary as a secondary form of hyperparathyroidism was already present in a patient with a phosphatdiabetes the clearance examination showed that under a high dosage of vitamin d the reabsorption of phosphate did not increase based on these results we have not continued therapy with vitamin d which is certainly not indifferent comparative renal clearance examinations were carried out in 10 patients which did not show any disturbances of calcium phosphate metabolism
MED	the unreliability of the titan yellow method for the determination of magnesium in patients receiving intravenous calcium gluconate gluconate was found to interfere with the determination of magnesium by the titan yellow method with this method false low results were found in the serum and urine of patients receiving intravenous calcium gluconate the interference can be prevented by ashing of the specimen
MED	absorption and excretion of toxogonin an alkyl phosphate antidote after intramuscular injection in man tolerance absorption and urinary excretion stu  dies of toxogonin bis  4 hydroxyiminomethyl  pyridine 1 methyl ether dichloride a specific anti  dote in poisoning by esterase blocking organic phosphates were made on 11 men by intramuscular injection of 250 mg ca 3 mg kg of the drug given by self injection ampoules injections made with the automatic ampoule autule caused no local irritation certain facial symptoms reported can for the time being be regarded as resorptive side effects of toxogonin maximum blood levels of 6 ug ml were recorded within 20 minutes even after four hours the level was still 1 2 ug ml a concentra  tion amply sufficient to ensure reactivation of blood esterases of the injected dose 52 was excreted in the urine after two hours 87 after eight hours toxogonin appears to pass through the body un  changed
MED	the study of osteoporosis and osteomalacia radiological evidence strongly suggests that osteoporosis with the possible exception of acute immobilization osteoporosis may be an irrever  sible condition the changes therefore to be expected in calcium balance when an osteoporotic is treated are small compared with those often seen in osteomalacia methods of obtaining more accurate calcium balances are needed to show these small changes especially when a high calcium intake is used the method of continuous marking of stools with chromium sesquioxide seems to provide just such a method using this method it has so far proved impossible to obtain prolonged large positive calcium balances in osteoporosis on either high calcium intake anabolic hormones or sodium fluoride two alternative therapies to vitamin d have been explored for use in vitamin d resistant osteomalacia atp has been found to be inneffective intravenous phosphate alone has been ineffective in producing positive calcium balances but is effective as a complement to vitamin d under certain conditions
MED	the aetiology and treatment of urinary calculus investigations in this laboratory have been based on the hypothesis that calculus formation is primarily a process of crystallization from super  saturated solutions rather than one of adsorption on a specific protein matrix as has been postulated by boyce and his colleagues boyce and king 1963 that crystallization is the primary factor is strongly suggested by the recent studies of vermeulen lyon and gill 1964 these authors produced artificial concretions which closely resembled urinary calculi by immersing a rotating wire loop in normal urine for several days and slowly adding the appropriate stone forming elements if the above hypothesis is correct then the factors of primary interest in urinary stone formation are those responsible for supersaturation nucleation and crystal poisoning much remains to be learnt about these various factors their inter relationships and their relative importance the significance of the urinary colloids proteins muco proteins and polysaccharides in calculus formation is still not clear but it is probable that they play an important secondary role in binding crystalline precipitates to form a non friable calculus since time is an important factor in crystal growth such non specific binding by proteins would increase the chances of stone growth and retention within the upper urinary tract
MED	control of idiopathic hypercalciuria the paper discusses the causes of hypercalciuria and describes 15 cases of different origins all of which presented similarly with renal stones the diagnosis of idiopathic hypercalciuria was made by exclusion the effects of dietary restriction of calcium sodium bicarbonate cortisone sodium phosphate sodium phytate and cellulose phosphate were demonstrated by calcium and phosphorus balance techniques all were shown to have some urinary calcium lowering effect finally a chlorothiazide derivative  namely bendrofluazide  was also demonstrated to have a hypocalciuric effect and the mode of action is discussed
MED	effects of parathyroid hormone and other proteins in vitro on mitochondrial metabolism it is apparent that in addition to parathyroid hormone several non hormonal basic proteins stimulate mitochondrial respiration ion transport and atpase but inhibit the 32pi atp exchange reaction thus these effects may not be so uniquely a measure of the biological actions of parathyroid hormone as the previous reports suggested rasmussen et al 1964 have also isolated from parathyroid extracts a protein that is inert in vivo but stimulates mitochondrial transport of phosphate in vitro they postulated that this protein might be yet another biologically important factor produced by para  thyroid glands the latter speculation may not be warranted in view of the uncertain specificity of protein effects on mitochondria all of our tests completed to date show that the non hormonal parathyroid proteins c1 and c2 are unrelated either biologically immunologically or chemically by amino acid analysis to the parathyroid hormone further rigorous studies are necessary to precisely determine whether any effects of parathyroid hormone on mitochondria validly reflect the mechanism of action of the hormone and whether it is sound to use the in vitro tests as bioassay tools
MED	the treatment of phosphatic encrusted cystitis alkaline cystitis with nalidixic acid phosphatic encrusted cystitis is caused by persistent infection by b proteus or ps pyocyaneus associated with an alkaline urine its incidence may be increasing and may follow megavoltage therapy of a bladder tumour its incidence in post radiation cases is 2 per cent mandelamine often fails to relieve this condition in this series of ten patients who had failed to respond to mandelamine eight responded to treatment with nalidixic acid no side effect of treatment was noted in the series nalidixic acid is of value in the treatment of b proteus infections of the urinary tract and is the drug of choice in the treatment of phosphatic encrusted cystitis
MED	role of the liver in the glycoprotein mobilizing property of parathyroid extract studies were carried out to de  termine the action of hepatectomy on the glycoprotein action of pte as well as on pte induced renal calcification and deposi  tion of glycoprotein our data showed that in hepatectomized rats pte no longer caused an elevation in serum glycoproteins how  ever hepatectomy did not alter the forma  tion of glycoprotein tubular casts produced by pte administration the data suggest that the liver is the major source of the ele  vated serum glycoproteins found in rats re  ceiving pte in addition it is possible that pte may have a direct stimulating action on biosynthesis of glycoprotein by the kidney
MED	distribution and excretion of radioactivity after parenteral administration of radioactive polydiethylstilbestrol phosphate to rats and a cow polydiethylstilbestrol phosphate psp a water soluble polyester of phos  phoric acid and diethylstilbestrol was in  jected in rats and a cow and the distribution and excretion of radioactivity were followed in both species after a subcutaneous or intramuscular injection the bulk of the radio  activity was accumulated at the site of injec  tion the disappearance of radioactivity from this depot was very slow as late as 90 days after the injection into rats 20 of the administered radioactivity was still accumu  lated at the site of injection the liver was very effective in removing labeled material from circulating blood twenty four hours after intravenous injection in rats about 50 of the radioactivity was recovered from this organ the distribution of radioactivity in the cow indicated that the polymer was preferably accumulated in organs containing reticuloendothelial cells
MED	study of phosphate excretion by the stop flow technique m de myttenaere the stop flow technique has been applied to the dog in an attempt to rule out tubular secretion of phosphate and to locate the site of action of parathyroid hormone p t h on the renal tubule under the experimental conditions used no significant inward transtubular movement of p32 could be demonstrated ruling out tubular secretion of phosphate stop flow experiments performed in parathyroidectomized dogs before and after p t h administration demonstrated inhibition of phosphorus reabsorption by the hormone in addition the stop flow pattern indicated that this phenomenon took place mainly in the distal part of the proximal tubules
MED	stupor hypercalcemia and carcinoma of the renal pelvis since albright suggested that some tumors might be producing parathyroid hormone hy  percalcemia associated with malignant tumors with  out bony metastases has been recorded with increas  ing frequency transitional cell carcinoma of the renal pelvis is here added to the list of neoplasms that hypercalcemia may accompany
MED	anodized aluminium grains labelled with radiophosphorus for medical purposes g b fasolo r malvano u rosa and e zimmer interstitial b therapy by implantation in tissues of radioactive sources is widely applied to the treatment of certain forms of human malignancies among the radio elements proposed for this therapeutic technique yttrium 90 and gold 198 are the most generally used radiophosphorus 32p shows some attractive features because of its suitable half life 14 3 days and its rather high energy b emission maximum energy 1 71 mev but the use of this radionuclide is limited by the diffi  culties found in the preparation of safe solid sources the only techniques we have found in the literature are those reported by riechert and mundinger and by rames and moravek who used respectively small plastic capsules filled with phosphomolybdic acid solution and ca po4 grains labelled with phosphorus 32 these methods require a delicate preparative work and moreover a large b self absorption effect can be expected in both cases a new simple method for the preparation of grains labelled with phosphorus 32 basically consists in ad  sorbing labelled po4 3  ions on an active aluminium oxide film produced by anodic oxidation of aluminium wire the adsorption capacity of the oxide film for po3 3  ions is quite high but the process is reversible the phos  phorus 32 activity is partially desorbed even after sealing in boiling water when the labelled wire is kept in isotonic sodium chloride solution
MED	effect of parathyroidectomy and ferric dextrin upon calciphylactic sensitization by uremia experiments on the rat indicate that calciphy  lactic sensitization can be achieved by bilateral nephrectomy intravenous administration of a ferric dextrin preparation fe din induces selective calcification in the buccal mucosa esophagus trachea and mediastinum of the nephrectomized rat although it produces no such changes in intact control animals conversely fe din prevents the cardiovascular calcification normally elicited by nephrectomy parathy  roidectomy protects the nephrectomized rat against the fe din induced calciphylaxis hence it may be concluded that 1 autologous parathyroid hormone in amounts secreted by the glands can act as a calciphylactic sensitizer and 2 fe din is highly effective in protecting the cardiovascular system against uremic damage
MED	mediastinal parathyroid adenoma a case of hyperparathyroidism with hypercalcemic crisis is presented the tumor was a well differentiated and encapsulated parathyroid adenoma un  usually located in the anterior mediastinum lying both within and without the pericardial sac the surgical approach was directly through the sternum with a mediastinal exploration the postoperative course was uneventful and gratifying with complete correction of both symptoms and abnormal laboratory findings
MED	clinical experience with primary hyperparathyroidism evaluation of treatment forty four patients with operatively proven hyperparathyroidism were evaluated to decide 1 whether or not the diagnosis could be substantiated by some postoperative observations other than the gross anatomic diagnosis of the operative specimen and 2 what the long term value of operative treatment would be it was found that an immediate and significant fall in urinary phosphorus excretion best documented the diagnosis of primary hyperparathyroidism over intervals up to 10 years follow up of the patients suggested a favourable response of the disease to operative treatment
MED	the dilution test as a measure of renal function in niobium poisoned rats control female albino rats given a water load of 50 ml kg excreted 50 per cent of this load as urine within 94 11 minutes teu50 the administration of a single intraperitoneal dose ranging from 10 to 30 mg nb kg resulted in 2  to 4 fold increases in the teu50 value 24 hours after the niobium was injected when niobium was complexed with ascorbic acid prior to injection the teu50 value was within control limits however rats given a single intraperitoneal dose of niobium and then given 3 doses of ascorbic acid at intervals of 1 3 and 6 hours showed teu50 values that were not markedly different from those observed in rats given niobium only increased teu50 values were observed in rats given single intraperitoneal doses of uranyl nitrate 1 2 2 4 mg u kg mercuric chloride 2 0 mg hg kg and sodium tripolyphosphate 480 mg kg
MED	influence of parathyroid activity on ion exchange in various tissues 1 balance data from three patients with hypoparathyroidism who were given parathyroid extract are presented the metabolic response was complex the data demonstrate losses of phosphate magnesium sodium and potassium which were not accounted for by destruction of either bone or non osseous tissues preferential depletion of these minerals from bone or loss from non osseous tissues must be presumed 2 the exchange of ca45 mg28 and p32 in a spectrum of rat tissues has been studied in sham operated parathyroidectomized and parathyroid extract treated rats the effects of parathyroidectomy on the development of magnesium deficiency were determined 3 four hours after parathyroidectomy increased transport of calcium into bone kidney intestine liver brain and muscle was found six days after parathyroidectomy equilibrium had been reestablished and exchange rates were identical to those in sham operated animals 4 the administration of parathyroid extract was associated with de  creased transport of ca15 mg28 and p32 into bone ca15 exchange in kidney was reduced but in all other tissues exchange of ca15 and mg28 was in  creased p32 exchange in both intestine and kidney was mardedly increased in animals receiving the extract 5 parathyroidectomy greatly minimized the manifestations of mag  nesium deficiency in young rats on magnesium deficient diets 6 the results suggest that parathyroid hormone may affect the trans  port and exchange of calcium magnesium and phosphate and perhaps sodium and potassium in tissues other than those usually considered to be target organs
MED	effects of alkalosis on plasma concentration and urinary excretion of inorganic phosphate in man acute respiratory and metabolic alkalosis have been shown to depress plasma phosphorus con  centration in normal man the fall in plasma phosphorus concentration is greater in respiratory than in comparable levels of extracellular meta  bolic alkalosis this fall is not attributable to in  creased renal excretion or to migration into red blood cells the evaluation of low serum phos  phorus concentrations should always be carried out with a knowledge of the ph and total co2 content of the plasma
MED	the relationship between vitamin d and parathyroid hormone marit von stedingk the effect of parathyroidectomy and parathy  roid hormone administration upon the concentra  tions of plasma calcium and phosphate have been measured in vitamin d deficient rats and the re  sults compared to those observed in d fed ani  mals also the influence of dietary calcium and phosphate content upon these responses has been investigated parathyroidectomy in the d fed ani  mal results in a rapid fall in plasma calcium and a biphasic plasma phosphate response with an initial fall followed by a striking rise in contrast parathyroidectomy in the d deficient rat is fol  lowed by no significant change in plasma calcium and an immediate rise in plasma phosphate that can be prevented by the administration of para  thyroid hormone dietary phosphate restriction abolished the effect of parathyroidectomy in both groups of animals administration of a dose of 500 u of hormone to the intact d deficient rat had little influence upon plasma calcium a dose of 2 000 u did in  crease plasma calcium a dose of 25 u was suffi  cient to increase the plasma calcium of the d fed animal these results are discussed in relation to the effects of vitamin d and parathyroid hor  mone upon mitochondrial metabolism
MED	decrease in serum and urinary phosphorus in man in the course of pyrotherapy during the fever peak occurring a few hours after the in  jection urinary phosphorus up dis  appears entirely this fact cannot be accounted for by the parallel decrease in gfr because serum phosphorus level sp does not increase as it would be expected to should retention occur but on the contrary it too declines to a marked degree the possibility that changes in sp and up could have been brought about by an increased utilization of glucose was also considered an intravenous glucose toler  ance test method of macho and licko 8 was carried out in another group of patients on control days and on days of pyrotherapy five hours after the pyrogen administration an increase in the rate of glucose utilization was observed table 2 however a different opinion is found in the literature in the course of glucose tolerance tests conn 3 and comparini 9 observed a lowered rate of glucose utilization in febrile subjects malizia 10 found an accentuated rate of decline of serum phosphorus during glucose tolerance tests in subjects with high temperatures but the glycemic responses did not differ from those ob  tained when controls without fever were subjected to the same tests whether it be for utilization purposes or not the fact remains that a massive transfer of phosphorus from the serum into the tissues takes place in fever
MED	relationship of maximal tubular phosphate reabsorption to filtration rate in the dog a maximal renal tubular rate of reabsorption of phos  phate tmp has been demonstrated in the normal dog in the dog as in the man considerable variability in the tmp often occurs while some of this variability remains unex  plained a direct relationship between glomerular filtration rate gfr and tmp can be demonstrated when the gfr is varied over a wide range this relationship suggests that glomerular intermittency may exist in the dog
MED	human growth hormone clinical measurement response to hypoglycemia and suppression by corticosteroids a standard test of growth hormone secretory ca  pacity based on radioimmunoassay of plasma growth hormone after insulin hypoglycemia is described in normal subjects a standard insulin tolerance test caus  ing an average blood glucose drop to 34 per cent of resting values produced a mean rise in growth hor  mone to 45 2 millimicrogm per milliliter at one hour with a total range of 25 to 70 millimicrogm per mil  liliter no response was observed in 5 hypopituitary subjects under comparable hypoglycemic stimulation glu  cocorticoid treated patients showed a marked in  hibition of the growth hormone response which was related to dose subjects receiving more than 60 mg of cortisol equivalent per day showed a mean plasma rise to 6 7 millimicrogm per milliliter range 1 5 to 13 millimicrogm subjects receiving 20 to 60 mg of cortisol equivalent per day showed a mean rise to 16 6 millimicrogm per milliliter range 13 to 20 millimicrogm inhibition of human growth hormone was also affected by duration of glucocorticoid treatment be  ing greater with long term than with short term ad  ministration
MED	obesity and plasma levels of insulin and growth hormone studies of serum levels of glucose free fatty acids insulin and growth hormone during prolonged fasting suggest that insulin and growth hormone are not responsible for certain metabolic abnormalities accompanying obesity
MED	hypophysectomy replacement therapy and the tolerance of the euryhaline killifish fundulus heteroclitus to hypotonic media hypophysectomized fundulus heteroclitus as previously reported survive only a few days after transfer from salt to fresh water survival time is the same when fish are tested 2 weeks or 2 months after hypophysectomy gradual dilution of the external medium produces failure at an average salinity of 0 26 0 67 0 02 this salinity is comparable to that causing failure after abrupt transfer although failure is associated with hypochloremia daily injections of a balanced salt solution or 0 6 nacl shorten survival daily injections of teleostean neurohypophysial peptides arginine vasotocin 2 25 and 0 0225 pressor mu per gram and isotocin 1 32 and 0 026 oxytocic mu per gram do not prolong survival an extract of caudal neurosecretory tissue urophysis from male tilapia mossambica had no beneficial action at doses of 50 ug per gram every other day purified ovine prolactin 105 mu per gram on alternate days maintained survival of 10 of 11 fish for the duration of the 28 day test period in fresh water irrespective of the period of pretreatment in salt water purified bovine prolactin prolonged survival and 2 of 6 fish were maintained for 28 days purified bovine growth hormone was ineffective monkey growth hormone containing 2 u per milligram of prolactin activity administered at a dose of 20 ug per gram equivalent to 40 mu per gram prolactin activity prolonged survival human growth hormone containing 4 u per milligram of prolactin activity at a dose of 20 ug per gram equivalent to 80 ml per gram prolactin activity also prolonged survival and 4 of 6 fish were maintained for 28 days the ability of pituitary preparations to protect hypophysectomized f heteroclitus from failure in fresh water appears to be related to their prolactin activity and not to their content of neurohypophysial peptides this suggests that an adenohypophysial hormone resembling mammalian prolactin is essential for survival of this fish in hypotonic external media carp pituitary preparations do not protect hypophysectomized f heteroclitus although f heteroclitus pituitaries are known to be effective
MED	resistance to human growth hormone in pituitary dwarfism clinical and immunologic studies thirteen pituitary dwarfs have been treated with human growth hormone hgh and growth acceleration with doses of 5 7 mg week has been observed in all but one patient on therapy this 7 1 2 year old girl grew at a rate of 1 05 cm month for 7 months thereafter despite larger doses of growth hormone 15 mg week growth rate fell to 0 27 cm month this rate of growth persisted after stopping hgh on retreatment on 2 occasions acceleration of growth did not occur antibodies to hgh absent in her serum before treatment were repeatedly demonstrated in her serum in high concentra  tion hgh binding capacity up to 100 mg 1 during treatment comparable titers of anti  body have not been found in any of the 12 other patients receiving long term hgh treat  ment the specificity of the human anti hgh serum differed from rabbit anti hgh serum whereas both monkey growth hormone mgh and hgh were effective inhibitors of the binding of hgh 131i by rabbit antiserum only hgh was an effective inhibitor with human antiserum in like manner a crude placental extract which was an effective in  hibitor for rabbit antiserum was ineffective with human anti hgh serum
MED	influence of alloxan diabetes on growth hormone content of the rat hypophysis homog  enates of adenophypophysial tissue obtained from alloxan  injected adult male rats varying in duration and severity of diabetes as well as from diabetic rats maintained on an insulin replacement regimen were assayed in immature hypophysectomized female rats the ability of these crude hypophysial extracts to encourage tibial cartilage width ex  pansion gain in body weight and to depress hematocrit and blood area levels was determined significant decrements in ability to increase epiphysial cartilage width and ability to depress hematocrits were noted 14 to 28 days following injection of alloxan increasing the intensity of the diabetic state was associated with decreased growth promoting potency of hypo  physial preparations as well as with decreased ability to influence the hematological indices hypophysial extracts taken from insulin treated diabetic rats contained more growth hormone than equivalent amounts of tissue obtained from control rats it is concluded that the adenohypophyses of diabetic rats contain diminished amounts of growth hormone and the insulin repairs or encourages greater than normal ac  cumulation of somatotrophin in these animals
MED	pheochromocytoma without hypertension the patient developed symptoms of pheochromo  cytoma about 15 years after the diagnosis of eosinophilic adenoma of the pituitary gland the predominating symptoms were profuse sweating and tachycardia hypertension hyperglycemia and glycosuria were absent the relation of the quan  tity and the relative composition of catechol amines to the symptomatology is discussed some speculation regarding the etiological importance of hypersecretion of growth hormone in pheochromo  cytoma seems to be in order
MED	hypoglycemia growth retardation and probable isolated growth hormone deficiency in a 1 year old child a heretofore unreported association of defects namely hypoglycemia growth retardation and deficiency of serum growth hormonelike activity in a 1 year old child is described human growth hormone hgh 3 mg a day for 7 days doubled the fasting blood sugar prevented the postprandial hypoglycemia and reversed the sensitivity to tolbutamide and leucine treatment with 1 mg of hgh 3 times a week produced a growth of 7 inches in 3 months compared to a growth of 1 inch in the previous 13 months since the protein bound iodine and the response to methopyrapone were normal and the blood level of growth hormone was low this case is presented as a probable isolated growth hormone deficiency
MED	production secretion and availability of insulin a more precise understanding of the metabolic phase of diabetes mellitus requires reliable information concerning the synthesis manner of release and transport of insulin as well as of the behavior of agents which interfere with the actions of the hormone by inhibition or destruction we shall deal with a variety of these problems here and it might be helpful at the outset to outline first our present understanding of the chemical structure of insulin since many useful hints flow out of a consideration of the nature of the molecule
MED	growth and growth retardation various attempts have been made over the years to define growth from the standpoint of this review growth is the physiological accretion of new tissue which is reflected in the acquisition of protein and water this process in almost all instances leads to increase in size length weight and volume and actively progresses from the fertilization of the ovum to the period of sexual maturity where millions of cells are present in a state of advanced organization with further time growth is less and indeed may become negative insofar as cells are lost
MED	long term treatment of hypopituitary and of achondroplastic dwarfism with human growth hormone we have treated an 8 year old hypopi  tuitary dwarf intermittently with hgh wilhelmi for 4 years with 1 mg 3 times a week the monthly growth rate was 1 4 inch as treatment continued he became resistant increasing the dosage to 3 mg 3 times a week at the age of 12 induced a monthly growth rate of 2 5 inch this growth promoting effect is at least as great as that reported for the li and raben preparations we have also treated a 15 year old severely de  formed achondroplastic dwarf for a year with 3 mg 3 times a week he grew 1 2 inch in the first month the spurt in growth subsided with 5 mg 3 times a week he grew another 1 2 inch in a month but growth was not main  tained
MED	acromegaly the effects of various steroid hormones on the insulin induced growth hormone response and peter h forsham the availability of a sensitive assay for human growth hormone has made it possible to directly measure the effects of various agents purported to alter growth patterns acromegalic patients present a special problem both in early diagnosis and in therapy being able to measure growth hormone in these patients provides an accurate index of activity and a precise measure of therapeutic effectiveness in an attempt to determine whether a pituitary block of growth hormone secretion is feasible in this condition a study was made of the effects of estrogen androgen and glucocorticoid administration on growth hormone response to a standard insulin tolerance test in a patient with active acro  megaly in the dosage schedules used in this study it was not possible to suppress either basal growth hormone secretion or blunt its responsiveness to the normal physiologic stimulus of hypoglycemia
MED	practical human growth hormone preparation and clinical use human growth hormone was prepared from acetone dried pituitary powder by hot glacial acetic acid extraction and subsequent precipita  tion by sodium chloride and cold acetone the yield was 13 per cent and the preparation was called practical growth hormone in recognition of its complement of corticotropin treatment of two dwarfs with practical growth hormone in aqueous solution 1 or 2 mg intra  muscularly on alternate days accelerated the growth rate and there were no physical signs or laboratory indications of adrenal stimulation or other adverse effects the preparation is recom  mended for its safety simplicity and relatively good yield
MED	hypophysectomy and the lipolytic action of epinephrine in vitro the response of normal adipose tissue to epinephrine 0 05 ug ml incubation medium is completely abolished by hypo  physectomy of the donor rats treatment of hypophysectomized rats with crude whole rat pituitary extract restored the lipolytic ac  tion of epinephrine to normal posterior pi  tuitary extract and corticotropin replacement was without effect thyrotropin injections produced a partial and growth hormone treatment a full restoration of the lipolytic action of epinephrine treatment of hypo  physectomized rats with cortisol or cortico  sterone reestablished the sensitivity of their adipose tissue to epinephrine but only when relatively large doses of these hormones were given physiological doses of triiodothyronine 1 ug rat day however restored the nor  mal response to epinephrine it is concluded that several endocrine factors can influence the lipolytic action of epinephrine but that their physiological importance cannot yet be quantitated
MED	c acetyl bovine growth hormone a procedure is described for labeling bovine growth hormone and human albumin with c acetylation the labeled molecule was biologically and antigenically similar to unlabeled bovine growth hormone following administration of the labeled hormone to animals the label appeared to remain attached to the growth hormone molecule for at least 4 hours administra  tion of the labeled hormone promoted growth in hypophysec  tomized rats and increased the free fatty acid concentration in rabbit serum to a degree comparable with that seen following administration of unlabeled growth hormone rabbit anti  bovine growth hormone serum neutralized the rat growth response to the acetylated hormone and immunized rabbits had altered isotope dilution and no increase in serum free fatty acids after intravenous injection of the labeled hormone
MED	growth hormone growth hormone influences protein fat carbohydrate and mineral metabolism it promotes nitrogen retention growth of cartilage transportation of amino acids through the cell wall and incorporation of amino acids into protein this factor mo  bilizes free fatty acids from adipose tissue and increases the serum concentration of these substances long term administration of this hormone is followed by depletion of body fat stores and inhibition of fatty acid synthesis in diabetic subjects growth hor  mone administration is followed by hyper  glycemia glycosuria and ketosis its effect on carbohydrate metabolism in normal sub  jects is more subtle sodium potassium and inorganic phosphate are retained following the administration of growth hormone hypercalciuria also accompanies such treat  ment an effect mediated through the para  thyroid glands human growth hormone may be detected in the serum through the use of the radio  immunoassay the hypothalamus is inti  mately involved with the control of the secretion and release of growth hormone from the pituitary there is a correlation between the availability of glucose for me  tabolism and the plasma concentration of growth hormone when glucose is unavail  able growth hormone is released in order to provide a substitute source of energy fatty acids the administration of growth hormone to the patient with hypopituitarism is fol  lowed by growth in many instances but it has not usually been effective in promoting growth in individuals with other abnormali  ties acquired resistance to the effect of growth hormone is accompanied by the de  velopment of antibodies directed against this protein
MED	recent advances in physiology of bone part i our introductory textbook summarizes knowledge of the biochemistry and physiology of bone and calcium metabolism up through 1960 in this lecture we will outline a few important advances appearing since that time references to the original literature need not be repeated here the object is to bring some of the subjects we are investigating up to date and to present new problems for laboratory research the hypothetical new hormone calcitonin of copp and cameron will be discussed in detail in dr mcleans lecture on the parathyroid glands and bone
MED	hyperplastic lesions of mouse mammary glands after treatment with 3 methyl  cholanthrene hyperplastic lesions were present in the mammary glands of mice treated with 3 methylcholanthrene and exogenous hormones the lesions were similar to those found in glands that were exposed to mammary tumor virus it is probable that the production of mammary gland hyper  plastic lesions could serve as a measure of the effectiveness of a chemical compound as a carcinogenic agent for the mammary gland
MED	bone growth and metabolic studies of premature infants treated with human growth hormone the influence of exogenous human growth hormone on growth and metabo  lism of premature infants was observed it was not possible to register any in  crease of linear bone growth after hormone administration concomitantly urinary hy  droxyproline excretion did not change significantly nitrogen balance studies indicated a sharp increase of nitrogen retention due to a reduced urinary excretion in all infants calcium and phosphorus balances rose in three out of four premature infants treated with growth hormone but the characteris  tic sth calciuric action of sth was not observed furthermore sth failed to in  duce any significant increase in nefa serum concentration of premature infants it may therefore be concluded that the metabolic response of premature infants to sth differs consistently from that normally observed in more mature subjects
MED	growth hormone action on rat liver rna polymerase the effect of growth hormone on the activity of the rna polymerase measured in this system is shown in table 2 it can be seen that hypophysectomy of the rat results in decreased activity of the rna polymerase and that the injection of 1 mg of human growth hormone into the rat 12 h before death increased the enzyme activity both in hypophysectomized rats and in normal rats however the stimulating effect of growth hormone was only seen in the absence of high concentrations of ammon  ium sulphate raising the ionic strength of the assay medium abolished the growth hormone effect it should be mentioned that addition of growth hormone in vitro in the presence or absence of ammonium sulphate has had no significant effect on the labelling of the rna by the nuclear preparations
MED	mammary growth in rats treated with somatotropin during pregnancy and or lactation groups of rats received daily injections of 2 mg somatotropin sth from either day 3 19 of pregnancy or day 1 13 of lactation another group of rats received graded increments 0 5 3 0 mg of sth every 6 days during both pregnancy and lactation other groups of rats served as pregnancy and lactation controls mammary gland deoxyribonucleic acid dna content was determined in all rats and milk yield was determined in all rats carried to day 14 postpartum significant increases in mam  mary dna occurred in all rats treated with sth irrespective of dose or schedule of in  jections when compared to gestation controls a significant elevation in mammary dna above the lactation control level was also evident in rats receiving the hormone and carried to day 14 of lactation milk yield of rats treated with graded increments of sth was significantly greater than that of control lactators but milk yield of rats re  ceiving a constant daily dose of the hormone did not differ from that of controls
MED	growth retardation accompanying diabetes insipidus an additional mechanism from the above considerations we may divide patients with nephrogenic diabetes insipidus into at least two categories 1 those who fail to respond to currently available therapeutic products as well as to their own presumably normal secretion of adh 2 those with similar similar unresponsiveness to treatment but with presumably reduced secretion of adh the adh growth hormone theory may well account in part for growth retardation in the later group
MED	studies on growth hormone secretion in rats with the hypophysis autotransplanted to the kidney capsule the secretory capacity of the pituitary gland autotransplanted to the kidney capsule was studied with special regard to the secretion of growth hormone gh body weight body length tibial epiphyseal width and the mammary gland development after testosterone stimulation were studied body growth and tibial epiphyseal width were markedly reduced in the rats with transplanted hypophysis but not as much as in the hypophys  ectomized controls after injections of 0 25 mg testosterone propionate daily for 10 days only a few groups of alveoli were seen in the mam  mary glands of the transplanted rats these observations show that there is a considerable deficiency of gh in rats with the pituitary gland auto  transplanted to the kidney capsule however the development of a few alveoli in the mammary glands is in favour of the theory that a small amount of gh is secreted from the transplanted pituitary tissue injections of a purified vasopressin preparation pitressin in the rats with autotransplanted hypophysis did not influence body growth tibial epiphyseal width or mammary gland development further no effect of pitressin was seen on the tibial epiphyseal cartilage of rats with intact pituitary gland as has been reported by del vecchio et al 1958 and hiroshige itoh 1960 these experiments therefore do not support the view that vasopressin acts as a gh releasing factor
MED	the effect of human growth hormone in hypopituitary dwarfism human growth hormone hgh raben has been used in a dosage of 2 mg m 2 day or 5 mg m 2 twice weekly this dosage is probably in or below but certainly not above the range of physiological replacement therapy in a standardized five day metabolic hgh test hypopituitary dwarfs retain more n than children without gh deficiency this test is valuable diagnostic help in hypopituitary dwarfism a prolonged treatment with hgh accelerates growth in hypopituitary dwarfs but not in children without gh deficiency growth rate induced by this treatment is first above average and later average or below average for age this decreasing response to hgh is typical for the general phenomenon of catch up growth and is not caused by the develop  ment of antibodies of 9 hypopituitary dwarfs treated for at least 9 months 3 were growth resistant from the beginning in spite of a high n retention in the preceding hgh test this resistance is caused by the development of high titres of specific hgh antibodies in the very first few months of treatment these antibodies suppress the effect of hgh both on metabolism and on growth the unexpected occasional induction in man of antibodies against a homologous protein hormone is of great interest the possibility that these antibodies might be active not only against the homogenous but also against the endogenous hormone could have a far reaching biological importance
MED	effects of short term administration of hysiological doses of human growth hormone in three patients with turners syndrome h e sjoberg the effect of apparently physiological doses of human growth hormone was investigated in three patients with turners syndrome in short term metabolic balance studies the subjects presented an abnormal sex chro  mosome constitution and an increased level of sulphation factor activity in serum two dose levels of hormone were used and there appeared an anabolic response to both no correlation with dose was obtained for any of the parameters used except for urinary magnesium where the retention was greater with the higher dose the sulphation factor activity of serum in  creased during hormone administration in the one case studied in this respect the urinary excretion of hydroxyproline was within the normal range in the two patients studied in this respect and was not altered by growth hormone all patients had an increased urinary excretion of creatine which at present cannot be explained the creatinuria diminished during growth hormone treatment the mechanism behind the retarded growth is discussed it is suggested that a major factor might be a defect in the center for linear growth i e the epiphyses that would make these less responsive to all the factors normally stimulating the growth processes in the epiphyseal zones
MED	the effect of growth hormone on kidney transamidinase in the hypophysectomized mouse the role of growth hormone and certain other endocrine factors in re  gulating kidney transamidinase has been investigated in the mouse the kidney transamidinase values are low following hypophysectomy growth hormone administration in doses of 0 5 to 5 0 ug day ovine nih restore the enzyme activity towards normal a bioassay for growth hormone is suggested based on the determination of the total kidney transamidinase intact mice that had been given relatively large doses of triiodothyronin had low enzyme activities enzyme values in alloxan treated mice were normal
MED	influence of hormones on tumor growth and plasma prolactin levels in rats bearing a pituitary mammotropic tumor the effects of estradiol cortisol acetate thyroxine or thiouracil on tumor growth organ weights and plasma prolactin levels were determined in rats bearing a furth pituitary mammotropic tumor mtt f4 this tumor is known to secrete large amounts of adrenocorticotropin somatotropin and prolactin but no follicle stimulating hormone luteinizing hormone or thyrotropin at the dose levels used estradiol significantly suppressed tumor growth without influencing body growth and it partially inhibited enlargement of the adrenals and atrophy of the thymus cortisol acetate significantly reduced both tumor and body growth thyroxine had no significant effect on tumor growth but enhanced the somatotropic effect as indicated by increases in body growth and organ weights thiouracil had no significant effect on tumor or body growth although it significantly increased thyroid weight estradiol cortisol acetate and thyroxine each increased the plasma prolactin levels of the tumor bearing rats
MED	studies with human growth hormone ten dwarfed patients whose short stature was of varying aetiology were studied by investigation of some of the metabolic effects of human growth hormone 10 mg being administered daily for a period of 5 to 9 days the patients were maintained on a constant diet during a preliminary control period while receiving hgh and in 7 patients from 2 to 7 days in the post hgh period hgh produced a reduction in serum cholesterol with a rebound on withdrawal in 7 a delayed clearance of fat from the blood after a fat load in 9 and the appearance of pre b lipoprotein in the fasting state as measured by paper electrophoresis in all of them the fall in serum cholesterol and the rebound on withdrawal of hgh has some relevance to the observation that hypercholesterolaemia occurs in some hypopituitary patients even in the absence of hypothyroidism no change was observed in tests of thyroid and adrenocortical function during the short term high dosage administration of hgh hypopituitary patients show a considerable retention of nitrogen on hgh administration and we have confirmed the work of prader and his colleagues that this provides a valuable diagnostic test for growth hormone deficiency the measurement of urinary nitrogen excretion after the withdrawal of hgh also promises to be a useful investigation in the differential diagnosis of short stature nitrogen excretion in the withdrawal phase in hypopituitary children returns slowly to its pre hgh levels two non hypopituitary dwarfed children excreted much more nitrogen in the withdrawal period than they retained in the hgh period one primordial dwarf showed a negligible change in urinary nitrogen excretion both in the hgh and in the post hgh periods
MED	hormonal modification of the distribution of 1 amino  cyclopentanecarboxylic acid 1 c14 in the rat four hormones have been examined for their ability to alter the distribution in the rat of the new model amino acid 1 aminocyclopentanecarboxylic acid 1 c14 although the total tissue concentrations of this amino acid were considerably less than those found previously for a aminoisobutyric acid the changes produced by the hormones were much the same for both amino acids hydrocortisone elevated the liver level of 1 aminocyclopentanecarboxylic acid within 2 hr bovine growth hormone accelerated entry of the amino acid into both skeletal muscle and liver of hypophysectomized rats within 1 hr testosterone propionate elevated its distribution ratio in the kidney but not in skeletal muscle whereas b estradiol significantly increased uptake of the model amino acid only by the immature uterus only growth hormone produced a significant change in the serum level of 1 aminocyclopentanecarboxylic acid under the conditions used
MED	insulin and insulin antagonism as i said earlier no simple answer has yet emerged from the large amount of research that has been directed toward determining the nature of the substance or substances responsible for the diabetes inducing and insulin antagonizing actions of the anterior lobe of the pituitary gland and to ascertaining their mechanism of action growth hormone and corticotropin certainly qualify but so do any other factors that can increase the mobilization of fats as plasma albumin bound free fatty acids the idea that the yet incompletely characterized insulin antagonist in the pancreas may be liberated into the blood under the influence of growth hormone and may play a role in the process by which growth hormone diminishes the activity of insulin in promoting the utilization of glucose is attractive to me but still remains to be confirmed
MED	relationships of growth hormone steroids and relaxin in the transformation of pubic joint cartilage to ligament in hypophysectomized mice the histological changes occurring in the pubic joint of hormonally treated intact or hypophysectomized mice have been studied estrogen treatment resulted in bone resorption and transformation of the cartilage caps of the pubic bones to fibrocartilage in intact mice but not in hypophysectomized mice furthermore relaxin failed to influence the appearance of the pubic joint of estrogen primed hypophysectomized mice whereas it induced the development of long interpubic ligaments in intact mice when growth hormone sth was administered to hypophysectomized mice the pubic joints responded to estrogen with bone resorption and transformation of the cartilage caps to fibrocartilage sth treatment also restored the ability of the pubic joint of hypophysectomized mice to proliferate long interpubic ligaments when estrogen and relaxin were administered progesterone specifically inhibited ligament formation due to relaxin injection without altering the histological changes associated with estrogen treatment both in intact mice and in sth maintained hypophysectomized mice
MED	effect of testosterone propionate and growth hormone on growth and chemical composition of muscle and other tissues in hypophysectomized male rats the effect of testosterone propionate and growth hormone on the growth of muscle bone pelt viscera and seminal vesicles was studied in hypophysectomized male rats testosterone 0 1 mg day stimulated growth in the levator ani muscle and seminal vesicles but had no effect on the other tissues studied growth hormone 0 1 mg day accelerated growth in all tissues except the seminal vesicles testosterone did not enhance the growth promoting effect of growth hormone in any tissue except the levator ani muscle growth hormone stimulated deposition of myosin sarcoplasmic proteins collagen and alkali soluble proteins in the thigh muscle of hypophysectomized rats the composition of the muscle in treated and control hypophysectomized rats was the same as that in normal rats growth hormone also increased the collagen keratin clastin and globular protein content of the pelt the effect of growth hormone on the proteins of muscle and pelt was not enhanced by testosterone testosterone given alone had no effect on the chemical composition or content of the muscle and pelt in hypophysectomized rats
MED	growth hormone and diabetes mellitus since the advent of insulin the vascular and neurological lesions have replaced ketoacidosis as the major problem in diabetes although good control of hyperglycemia and glycosuria with diet and insulin may influence favorably the development of the ocular angiopathy there remains a high incidence of these lesions with resulting blindness despite such good control growth hormone may be a major factor in the pathophysiology of diabetes mellitus and its effects may be a reflection of the genetic disturbance its importance was first realized by the classical experiments of houssay and those of young which revealed its diabetogenic effects in experimental animals the association of acromegaly with diabetes has been for a long time the major argument in support of the hypothesis of the diabetogenic effect of growth hormone in man
MED	experiments on the contribution of somatotrophin to prenatal growth in the rat hypophyseoprivus in a fetal rat induced by decapitating the fetus in utero retards fetal growth this effect can be prevented by injected somatotrophin these observations substantially support the view that in the normal rat shortly before birth the fetal somatotrophin from the developing hypophysis governs in part the prenatal growth which occurs at that time although complete hypophysectomy of a pregnant rat retards the growth of fetuses the manner of its action is obscure in an individual litter combined hypophysectomy of the mother and hypophyseoprivus in a fetus retards fetal growth but not to any greater extent than hypophysectomy of the mother without hypophyseoprivus in the fetus in the intact fetus injections of somatotrophin armour do not accelerate fetal growth presumably because ample fetal somatotrophin from the developing hypophysis is present
MED	insulin and protein metabolism the present status of protein synthesis within cells has been outlined protein is formed in the absence of insulin the net formation of protein is accelerated by insulin the effects of insulin on protein metabolism take place independently of the transport of glucose or amino acids into the cell of glycogen synthesis and of the stimulation of high energy phosphate formation in the case of protein metabolism as in certain studies on the pathways of glucose and fat metabolism these observations reveal striking intracellular effects of insulin in many tissues within most tissues the effect of insulin appears to find expression predominantly at the microsomal level incidentally other hormones which affect protein metabolism such as growth or sex hormones appear to act at the microsomes the fact that insulin exerts effects on protein metabolism at other intracellular sites as well as the above independent effects leads one to agree that its action consists of a stimulation of multiple seemingly unrelated metabolic events the fact that an immediate effect of insulin on protein synthesis is independent of the immediate need for extracellular glucose or amino acids does not mean that the sustained functioning of cells is likewise independent the biochemist is fully aware of metabolic defects in diabetes which are not altered by insulin in vitro but which demand varying periods of pretreatment of the animal it is also known that in diabetes some proteins enzymes may be deficient while others may be produced in excess in the absence of insulin it is suggested that the physician desires at least two kinds of relation between these fundamental studies and his patients one is the possible relation of a deficiency of insulin action to pathological processes in tissues which have not as yet been examined by the methods described the other is the need for more accurate measurements of the metabolic disorder and its control than such things as urinary and blood glucose in developing such future improvements the place of insulin in protein biosynthesis must be kept in mind
MED	the influence of blood glucose on the plasma concentration of growth hormone a berson m d a sensitive and specific assay method has been used to demonstrate acute changes in plasma hgh in normal and diabetic subjects hgh secretion is suppressed by glucose administration and markedly stimulated by hypoglycemia by interference with intracellular glucose utilization high levels of hgh were also observed during prolonged fasting after exercise and four to six hours following oral glucose administration abnormalities in hgh secretion were found in association with acromegaly and obesity and following section of the hypophyseal stalk the half time for disappearance of endogenous plasma hgh is twenty to thirty minutes
MED	failure to thrive the diencephalic syndrome of infancy and childhood we have presented a case of a patient with an astrocytoma of the optic chiasm who demonstrated the features of the diencephalic or failure to thrive syndrome overactivity overalertness and emaciation were significant symptoms in this patient roentgenograms characteristically demonstrate normal bone growth good muscular outline and absent subcutaneous fat increased growth hormone was found and may be a factor in the disturbed lipid metabolism
MED	increased stature the fact that some patients respond to growth hormone administration with linear growth does not indicate growth hormone deficiency or hypopituitarism yet this appears to be the main factor that led these authors to assume that their patients were suffering from hypopituitarism the conclusion that children with growth retardation should be subjected to a short trial period of treatment with growth hormone to single out those who are deficient in growth hormone is therefore of questionable validity rather because of the limited supply of human growth hormone it appears that much more stringent criteria for administration of human growth hormone should be advocated every effort should be made to uncover the patients who might benefit from growth hormone by utilizing reliable tests of pituitary function and perfecting a suitable growth hormone assay those who have more than suggestive evidence of hypopituitarism and growth hormone deficiency should then be treated and carefully evaluated for response after long term treatment
MED	on language disorders in young children a reorganization of thinking current questions and confusions about the use of the term aphasia with reference to young children seem often to reflect semantic problems accruing from professional habits of thinking in terms of etiologic and pathologic labels it is argued that if the term aphasia is generalized simply to refer to inabilities or interferences in the development of language comprehension and use then it is the task of an evaluating group to describe as well as possible and in detail the specific impairments of function in each child this task commonly requires the use of an extensive period of diagnostic teaching wherein care is taken to explore which sensory and motor modalities are working and which are not and whether integration of various stimuli is taking place some current ideas are discussed with reference to descriptions of impairment causal factors that are fairly unique in childhood some thoughts about the neurophysiology of the human language system and some psychosocial factors important for language learning special attention is given to various relations in terms of temporal resolving power between sensation and sensory integration a scheme or model is suggested which may prove fruitful for experimental design in attacking some of these problems at a prelanguage or premeaning level it is argued that the proportion of unknowns can be reduced by careful study based on information about impaired functions within the sensory integrative motor complex without particular regard for site and extent of lesion
MED	therapy for hearing impaired children in comparison with the u s a and europe canada is still in the early stages of developing rehabilitative services for speech and hearing impaired children and adults they are available in some large canadian cities but in the opinion of the authors these services and more should be made available to the hearing impaired of every canadian community specialists in the rehabilitation of communication problems along with members of other medical paramedical and social services recognize the vast variety of communication problems that can occur in persons of all ages the tremendous handicap that such problems represent to the individual the loss that such handicapped persons represent to our society and the pressing need for efficient and effective rehabilitation more practically it is hoped that this article has made its readers more aware of the vast variety of rehabilitative procedures available today for the hearing impaired with a better understanding of the problems of defective hearing it is hoped that all readers professional and non professional will join in mutual support for the establishment of these vitally needed services in their respective communities
MED	baby habits genesis and ontogenesis for adam may be looked upon as the personification of paleolithic man 100 000 generations of primitive human animal whose evolution can be of vast importance to the understanding of the ontogenesis of the behavior of babies not for nothing did the deuteronomist reiterate remember the days of old consider the years of many generations
MED	speech therapy with selected patients with congenital velopharyngeal inadequacy this paper has described the clinical speech problems of three patients without cleft palates but with velopharyngeal inadequacy pharyngeal flap surgery was performed on each patient after speech therapy was found to be ineffective following systematic trial therapy continued following the surgery the youngest child a first grader realized normal speech following the surgery and therapy the two other children continue to have aberrant but improved speech
MED	stimulus overload action cycles and the completion gradient systematic inquiries into the origin of certain emotional disturbances of infants show that consistent maternal care is vital for the childs normal physical psychic and social development indeed for his survival the most elementary precondition for consistent maternal care is the physical presence of the mother or her substitute it has however become increasingly apparent that childrens development can also be stunted and that they suffer damage of varying extent by the attention of and close contact with a mother who dispenses what seems to be the wrong kind of mothering a model of the mother baby interaction is proposed to explicate the dynamics of the wrong kind of mothering and its consequences my proposition is that the mutual exchanges between mother and baby consist in a give and take of action and reaction between the two partners which requires from each of them both active and passive responses these responses form series and chains the single links of which consist in what i call action cycles each completed in itself and at the same time anticipating the next link i designated these seriated response exchanges as the precursor of dialogue as a primal dialogue the dialogue acts as a vector of the babys development influencing its direction and stimulating it to adaptive efforts and psychic growth it follows that inappropriate mothering quantitatively as well as qualitatively results in what is referred to at this time as the derailment of the primal dialogue controlled experiments with animals findings of experimental psychology and lastly clinical findings illustrate the mechanics of the derailed dialogue and its sequelae in the cases under review a surfeit of stimulation a psychic overloading resulted in the derailment of dialogue overloading prevents its subject from completing actions or responses initiated by him long lasting overload results in the cumulation of incompleted action cycles the sequelae of this cumulation are profound changes in the behavior of the individual these changes are manifested in a departure from the norms of individual and social behavior patterns that are maladaptive for the individual and asyntonic with his society that is asocial the derailment of the dialogue is triggered perhaps even caused by the nature of the social setting one setting over population is extensively discussed in connection with an animal experiment and the implications for the human community are examined
MED	children at kelbourne kelbourne school glasgow which educates both spastic and aphasic children is the first school of its kind to be administered by a local education authority its aphasic department largely experimental in nature contains children aged three to eight in the spastics department there are 45 children with severe physical handicaps and their ages range from 3 to 16 the school which celebrated its golden jubilee last year has its origins in the maryhill hall public school for defective and epileptic children which opened in 1907 with 12 pupils in premises of which as an h m i reported four years later it was impossible to speak favourably the report continued a public hall used frequently in the evenings for public entertainments lacking proper cloakrooms bare in appearance and generally comfortless should not be used for this purpose the inspectors words did not go unheeded and seven years later the children were transferred with others to the new buildings of percy street special school in the 1950s the name was changed to kelbourne school between and through two world wars the school provided education for physically and mentally handicapped children but in 1955 a new unit was added and spastic children were admitted for the first time gradually the emphasis shifted from children with other physical and mental handicaps to the cerebrally palsied and finally the entire building became available for spastics two years ago the aphasic children joined the school miss e f hamilton is the headmistress
MED	deafness methods of detection diagnosis and management of deafness in children depend so entirely on a knowledge of the processes involved in communication by speech and in the acquisition of this skill that i propose to consider them first it will be found that the practical steps to be taken in dealing with patients flow naturally from this knowledge
MED	pharyngoplasty in speech where adequate palate repair is undertaken at 1 year there is no indication for pharyngoplasty as well at that age pharyngoplasty is indicated as a supportive operation only when the result of the palate repair can be assessed 5 years plus and where the speech result proves disappointing the figure of 171 pharyngoplastics in 944 cases applies to the known speech results up to april 1963 it follows that with follow up of the more recent primary cases pharyngoplasty may well be necessary in some the hynes pharyngoplasty has proved to be the most satisfactory
MED	verbal effects in the intermediate size transportation problem preschool children were given an intermediate size discrimination problem told before each response that the reward was under the medium stimulus and 1  and 3 step transposition tests during training group i was group ii was told that it was not under the big or little one and group iii was not told anything the verbalizations were not given during the tests groups i and ii learned the initial discrimination faster than group iii and transposed more than group iii but there was a distance effect in all three groups these results and other data suggest that the deficiency in the verbal control over motor behavior in young children arises from deficiencies in both the decoding and encoding processes
MED	the acquisition of formal features of language children from different groups do not learn the same uses and functions for language but every child must learn the formal features or the code for his language thus creating a constant in every language acquisition situation
MED	mongolism some clinical aspects this is a review of 86 mongoloids seen over 5 years at the nebraska psychiatric institute one half of the sample were evaluated before their second birthday eighteen per cent of the cases for whom birth weight data were available weighed less than 5 1 2 lbs double the national rate for prematurity there was a bi modal distribution of mothers age at the birth of the mongoloid child pregnancy labor and delivery complications were reported in almost one half of the cases seven per cent were breech deliveries all cases were mr the most frequent type was moderate most frequently mentioned characteristics were generalized hypotonia all but 2 cases psychiatric disorders 11 cases abnormal eeg 8 cases hearing loss 5 cases
MED	learning problems in children ii emotional aspects at the last meeting we tried to deal with a general over all approach to the problem of learning considering it not merely as a problem in reading but learning in general which begins at birth we hope to deal with this problem at a relatively high level and we want to have the emotional problems dealt with in this manner rather than in terms of diagnostic criteria the child with learning problems should not be compartmentalized in terms of organicity and nonorganicity the subject of this talk then is emotional issues in learning
MED	management of communication problems in infants and children early detection and referral of a child with a hearing or speech language problem is feasible and in most cases very critical further consultation can then be obtained and the child placed on a training program geared to his needs
MED	the formation of a cleft palate unit  a preliminary report with cleft palates as in other surgical fields changing techniques and better management of the patient as a whole render inexcusable the operative procedures that merely drag together the edges of the defect and then leave a cosmetically and functionally crippled child to adapt itself as best it may to the harsh competition of the outside world ironically the problem of congenital defects increases as our competence to deal with them advances in the past these cases struggled to take their place on the marriage market but the more skilled our rehabilitative procedures become the more likely are they to perpetuate their disability since a significant number show a hereditary tendency
MED	acquisition of language although the work of bullowa jones and bever has some of its greatest promise in the light it may shed on the development of functions of language in children the promise cannot be realized unless the authors give a great deal of explicit attention to the framework of such analysis for there is not as may be the case for phonological and grammatical development anything like a satisfactory body of linguistic theory and method as to the terminal state while a good deal may be learned without such a theory and necessarily must be so learned since the work in progress cannot be suspended until such an unpredictable millenium it still would be a pity if the chance were lost for the interaction of the acquisition of data and the improvement of theoretical notions let me complete my discussion by developing my argument in two ways a by briefly stating the nature of the problem with regard to the terminal state of verbal development b and by indicating what present and future contribution such fields as anthropology sociology and social psychology may be able to make to the solution of the problem
MED	the speech production and spoken language of the deaf the distinction was made between speech production and spoken language in analysing the oral output of those with hearing impairment a brief review of studies in both areas was undertaken including the report of a new electronic visual monitoring device the glossal transducer it was postulated that the deaf utilise a unique visual to motor conversion within the brain when speaking and monitor conscously by tactile kinaesthetic control the more recent studies relate to the syntactical features of the speech of the deaf these show that deafness creates telegraphic speech with reduced sentence length and omissions of essential words such as functors the speech of the deaf seems to contain mostly nouns and verbs with a limited number of words used to expand verb forms
MED	cognitive functioning in early infantile autism an examination of four cases by means of the wechsler intelligence scale for children the results are communicated which were obtained from an examination by means of the wechsler intelligence scale for children of four cases of early infantile autism these cases had developed in such a way that a reliable investigation by means of a mental test had become possible according to their full scale iqs the four cases fell within the category of dull normal intelligence or less all of them showed a considerable discrepancy between the verbal and the performance iq the performance iq being of much higher value the composition of the autistic test profiles was characterized by a large variability in the subtest scores discriminating the autistic group significantly from non autistic control groups the subtest score divergencies responsible for the large variability showed a distinct pattern being specific for the autistic group as a whole this group could be considered as a distinct group particularly by a marked tendency to achieve poorly and far below the subjects average level in the subtests comprehension and vocabulary and to achieve superiorly and far above that level in the subtests block design and object assembly by specifying the mental functions conditional for success in these four subtests that occupy extreme positions within the autistic test profiles it was concluded that the autistic patients apparently were able to achieve well or even superiorly only if the task could be performed on a purely perceptual level but they failed as soon as an appeal was made to thinking proper this was thought to be due to a disability in dealing with imaginary things and imaginary situations or in other words to an incapability to objectify what is not actually present in the subjects concrete situation it is proposed that this impairment could be reduced to a lack of symbolic means being the correlate of a defective or insufficiently developed language in the patients it is further proposed that children suffering from early infantile autism might not be able or at a later stage only to reach that level of language development in which words can be used as symbols representing absent things and absent situations
MED	otologic care of cleft palate cases the purpose of this study was to review the ear pathology in 480 patients whose cleft palates had previously been repaired despite concern over speech regression tonsil and adenoid surgery was carried out on 66 of these patients when carefully done this was accomplished with considerable overall improvement particularly for the benefit of the conductive hearing loss sixteen cases had exact documentation of these results by virtue of speech recording and accurate audiometric records
MED	congenital heart disease deaf mutism and associated somatic malformations occurring in several members of one family m d and patrick h lehan m d a unique family is described in which the mother and four of her eight children have pulmonary stenosis two of the four affected children are deaf mutes one of these has in addition to the pulmonary valvular stenosis idiopathic hypertrophic subaortic stenosis all the affected children had several associated somatic malformations genetic and nongenetic factors and their role in the development of the malformations are discussed it is suggested that the cardiac defect is transmitted by a single non sex linked genetic factor dominant autosomal inheritance in the presence of a normal karyotype it appears that a single dose of either a point mutation or a small deletion or translocation is the most likely cause
MED	histidinemia a review of published reports of histidinemia indicates that this condition has a variability of clinical and biochemical expression three children with histidinemia born of a consanguineous marriage are reported here they had blond hair blue eyes speech defects mental retardation and a peculiar eeg abnormality they also exhibited characteristic biochemical findings of the disease elevated blood and urine histidine increased urine imidazolepyruvic acid and a sustained high rise in plasma histidine following an oral histidine tolerance test they did not however have the reduction of skin histidine a deaminase activity which has been observed in some children with this condition tests for determination of heterozygotes in the family were not successful parental consanguinity and normal skin a deaminase activity set these children apart from other reported cases the first lends support to the hypothesis that histidinemia is inherited as an autosomal recessive trait the second supports the idea that the genic fault which results in reduced histidine a  deaminase activity can be expressed to a different degree in different tissues these children seem to represent a variant of histidinemia where liver histidase activity is reduced while skin histidase activity is present
MED	interpretation within the metaphor analytic investigation of the use of the metaphor was first given impetus by ella freeman sharpe 1950 who explored the symbolic meaning of particular metaphoric phrases with reference to the body and libidinal needs currently interest has become focused upon the use of the metaphor as a self conscious rational therapeutic technique of communication of particular value with those patients who have reached the borderline of sanity ekstein 1961 and ekstein and wallerstein 1957 have emphasized that the use of the metaphor should be regarded as an essential technique for gradually establishing communication and initial insight with borderline and schizophrenic patients but that it must not be regarded as a treatment technique in itself it is but a preliminary approximation to the final therapeutic act which ultimately will consist of a classical interpretation at the level of the secondary process the use of the metaphor derives its primary value from maintaining contact with patients who are constantly in danger of being inundated by a break through of primary  process material
MED	evolution of a characteristic speech disorder in juvenile cerebral lipidosis juvenile cerebral lipidosis is being diagnosed with increasing frequency in this country especially in schools for the visually handicapped the manifestations of rapidly developing loss of vision seizures muscular rigidity ataxia retinitis pigmentosa and eeg abnormalities are well known in this disorder a speech disorder described as a lolling stammering speech was mentioned by sjogren 1931 in his comprehensive description of juvenile amaurotic idiocy but this has not been emphasized in recent descriptions this report based upon an analysis of 5 cases describes the evolution of a characteristic form of speech pathology that is invariably present in juvenile cerebral lipidosis the initial speech abnormality seen early in the disorder is a hesitancy of speech and occasional repetition of words in time dysarthria becomes evident with slurring nasality and impairment of phonation similar to that seen in pseudobulbar palsy in addition to the dysarthria a highly characteristic perseverative speech appears which often has a close resemblance to true stuttering this stuttering like speech has been observed in 4 of the 5 cases at some time during the course of their illnesses as the speech patterns deteriorate the patient becomes less communicative and finally lapses into mutism the speech disorder is often the most disabling aspect of this syndrome
MED	relation of crying activity in early infancy to speech and intellectual development at age three years rosenfeld cries of 38 infants age 4 to 10 days were measured for outburst frequency during the most active 20 sec period of crying crying scores showed a significant correlation 45 with stanford binet iq at 3 years a borderline correlation 32 with cattell iq at 15 to 20 months and a nonsignificant trend with speech ratings at 3 years although no correlations were adequate for individual prediction infant crying is deemed worthy of further investigation as a possible indicator of intellectual potential
MED	labial supportive appliance the patient with a repaired cleft lip and palate and an associated displacement and deficiency of the premaxilla presents problems which may be of concern to the plastic surgeon speech pathologist orthodontist and prosthodontist the upper lip may appear flat or retruded in relation to the lower lip when maxillary anterior teeth are missing either congenitally naturally as in the mixed dentition period or because of neglect the upper lip may appear to be rolled under the premaxilla the lower lip usually assumes a characteristic pouty appearance this complex of tissue deformities also may be important in the articulation of speech sounds fricatives and plosives are difficult to produce correctly because of the malposition of the lip there may be interference with direction of air current contact of tongue to alveolar ridge and normal contact of lips corrective procedures are designed to improve the labial profile and to establish more normal relationships of intraoral structures these procedures employed individually or in combination may include othodontic movement of maxillary segments dental prosthesis and cheiloplasty another more recently developed adjunct involves autogenous osscous implantation in the cleft areas
MED	heterogeneity of the cleft palate population and research designs the primary point made in this paper is that we must reject the notion that there is some inherent universal commonality among individuals who are born with a cleft lip and or cleft palate we must recognize the various pertinent subgroups within this population this does not mean however that one must always recognize the smallest subgroup in doing a given study on the contrary we would defend the use of fewest possible subgroups consistent with the specific research purpose nevertheless we feel that time spent considering the purposes of a study and the subgroups which need to be identified will tend to minimize the number of contradictory results and will assist us in the interpretation of the observations that our insight and technology make possible
MED	cineradiographic comparison of normal to noncleft subjects with velopharyngeal inadequacy cineradiographic studies of the normal subjects were compared with studies of noncleft subjects who demonstrated velopharyngeal inadequacy the following conclusions were made a there was a significant difference between soft palate length in normals and the velopharyngeal inadequacy group b there was not a significant difference between depth of nasopharynx in normal and the velopharyngeal inadequacy group c the difference of the means of the soft palate length and depth of nasopharynx between the normals and velopharyngeal inadequacy group was significant d the thickness of the soft palate was greater in the normal than the abnormal group e in 70 of the normal and velopharyngeal inadequacy groups the height of soft palate elevation was above the palatal plane f in 80 of the normal group the height of velopharyngeal closure took place below the palatal plane none of the subjects in the velopharyngeal inadequacy group obtained velopharyngeal closure g there was no significant correlation between amount of gap and voice quality h there was no significant correlation between amount of gap and intelligibility of speech i there was a difference between vital capacity readings for the velopharyngeal inadequacy group with nose occluded and unoccluded j the correlation coefficient between quality judgment and intelligibility judgment was highly significant
MED	spontaneous verbal rehearsal in a memory task as a function of age a distinction is made between 2 alternative hypotheses for explaining an often reported deficiency in verbally mediated performance during early childhood 1 the verbal response is made but tends not to mediate performance mediational deficiency hypothesis 2 the verbal response tends not to be made production deficiency hypothesis a study is described which attempts to meet the ideal criteria for a test of the production deficiency hypothesis the method used was that of direct observation of ss spontaneous verbalizations and the hypothesis was confirmed by the finding that kindergarteners are less likely than older children to rehearse stimulus names in a nonverbal serial recall task
MED	early experience and the socialization of cognitive modes in children this paper deals with the question what is cultural deprivation and how does it act to shape and depress the resources of the human mind the arguments presented are first that the behavior which leads to social educational and economic poverty is socialized in early childhood second that the central quality involved in the effects of cultural deprivation is a lack of cognitive meaning in the mother child communication system and third that the growth of cognitive processes is fostered in family control systems which offer and permit a wide range of alternatives of action and thought and that such growth is constricted by systems of control which offer predetermined solutions and few alternatives for consideration and choice the research group was composed of 160 negro mothers and their 4 year old children selected from four different social status levels the data are presented to show social status differences among the four groups with respect to cognitive functioning and linguistic codes and to offer examples of relations between maternal and child behavior that are congruent with the general lines of argument laid out
MED	recovery of mycoplasmas in the study of human leukaemia and other malignancies numerous reports have been published concerning the necessity of testing for the presence of mycoplasmas before the interpretation of experiments performed in cell cultures such tests are especially important when the presence of viruses is suspected since recent evidence indicates that some mycoplasmas are capable of eliciting a transmissible cytopathic effect in addition some mycoplasmas and viruses share properties such as size filterability morphology in electron microscopy sensitivity to ether ability to haemagglutinate and cause haemadsorption interference with virus replication in vitro lack of inhibition by certain commonly used antibiotics and inhibition of growth by homologous antiserum thus the absence of ordinary bacteria and moulds in preparations eliciting a cytopathic effect in cell cultures is an unreliable criterion for viral identification great caution should be exercised in classifying new agents as viruses especially as myxo  viruses without adequate testing to exclude their identity as mycoplasmas
MED	pneumonia due to mycoplasma pneumoniae its incidence in the membership of a co operative medical group ruth mcmahan edmund r clarke william a maccoll and j thomas grayston a total of 1051 cases of pneumonia occurred in 72 992 persons who were members of a medical co operative in the period december 1 1963 to december 31 1964 the annual rate of pneumonia was 12 9 per 1000 isolation of mycoplasma pneumoniae from throat swabs was attempted in over half the cases reported and paired blood specimens were obtained in one third on the basis of laboratory examination of these specimens the incidence of clinically recognized pneumonia due to m pneumoniae was between 1 and 1 5 persons per 1000 per year although peak rates of pneumonia occurred under five years of age 45 per 1000 pneumonia due to m pneumoniae was uncommon in this age group it was most common in children five to nine years old and was frequently the cause of pneumonia in adolescents ten to nineteen years of age the rates in children in primary school was twice the average incidence m pneumoniae pneumonia also differed from the pneumonias of other etiology in that it occurred throughout the year with no seasonal excess whereas total pneumonia showed a predominance in winter the typical clinical syndrome of the pneumonias in which m pneumoniae was isolated was one of prominent systemic manifestations of headache and fever but few respiratory symptoms occurred except cough upper respiratory tract complaints and an elevated white cell count were much more frequent in the other pneumonias the patients with m pneumoniae pneumonia were almost never hospitalized but suffered significant absenteeism they came from larger families usually with children of school age reporting physicians were usually correct in diagnosing these pneumonias as atypical or viral
MED	establishment of a turkey flock free of n strain mycoplasma mycoplasma of the n strain are frequently isolated from turkey poults affected with airsacculitis but free of mycoplasma gallisepticum research on the n strain has been impeded by the presence of a high proportion of turkey poults with airsacculitis in all breeding flocks examined by the difficulty of culturing and identifying the mycoplasma strains and by the lack of a practical serologic test this communication describes the establishment of a small nucleus of n free turkeys from a commercial breeding flock known to carry n mycoplasma hens and toms for the production of n free poults were selected from the parent flock by serology and culture
MED	septicemia due to mycoplasma hominis type 1 viola m young ph d and sheldon m wolff m d a febrile illness that followed therapeutic abortion and was accompanied by the presence of mycoplasma hominis type 1 in the blood is described the patient upon recovery exhibited a specific antibody response to the mycoplasma isolated from the blood as well as to another strain of the same serotype these findings are regarded as additional evidence for the pathogenicity of m hominis type 1 organisms particularly in situations favoring their dissemination from the female genital tract
MED	infectie door mycoplasma hominis bij een pasgeborene mycoplasma hominis infection in a newborn child   in a baby born by a difficult forceps delivery abscesses began to form in the neck a few days after birth mycoplasma hominis was recovered from the pus
MED	some intraspecies differences in antigens on the surface of certain living human cells surface antigens of several types of living cells of human origin were partially characterized with hyperimmune antisera prepared in the rabbit against living hela cells and living uncultured full term human amnion cells hemagglutination mixed agglutination and direct and indirect immunofluorescence fab techniques were employed with these techniques and fractional absorption procedures common and specific cell antigens were detected on the surface of several human living cells uncultured and primary amnion two established human cell lines rp am 1 and u amnion of presumed normal origin and two hela and hep 2 of presumed malignant origin and human erythrocytes none of the antigens were found on nctc 2555 mouse cells the human cells possessed species  related antigens demonstrable by hemagglutination after removal of the hemagglutinins by absorption with human erythrocytes antibody in high titer for the homologous cells was detected by fab methods in addition some changes in antigens on the surface of amnion cells during primary culture were observed finally an antigen was found on hela and hep 2 cells by use of anti hela serum absorbed with human erythrocytes and rp am 1 cells that was not found on either human erythrocytes uncultured amnion cells or on the cells of the two established amnion cell lines at the dilutions used in the tests antibodies to the abo blood group isoanti  gens forssman hapten or adsorbed serum proteins could not account for the antigens detected the possibility that mycoplasma sp antigens were responsible for the reactions was inconsistent with the results the specificity of the fab methods on living cells was confirmed
MED	coombs positive hemolytic anemia and generalized amyloidosis in mice following transmission of subcellular leukemic material following transmission with cell free supernatant fluid or with virus ex  tract of leukemic tissue or plasma from vari  ous types of murine plasma cell leukemias a disease developed characterized by hyper  gammaglobulinemia weight loss anemia marked splenic renal and hepatic amyloido  sis and plasma cell infiltrations in the lungs the disease was also transmissible through the placenta or with the milk of infected mice in dba 2 males the incidence of the disease was much higher 100 the sur  vival shorter and the anemia much more severe than was the case in dba 2 females and in dba 2 x cba f1 mice of both sexes it is proposed that the development of the lesions is mediated through an auto  immune mechanism created by the antigenic effect of the virus transformed host cells
MED	the ph 6 antigen in strains of pasteurella pseudotuberculosis and its relation to biological activities it may be concluded that only part of the p pseudotuberculosis strains can synthesize the ph 6 antigen whereas this property seems to be shared by all the strains of p pestis as in the case of p pestis three kinds of biological activi  ties were related to the presence of the ph 6 antigen isolated from a strain of p pseudotubercu  losis
MED	serological relationships among human mycoplasmas as shown by complement fixation and gel diffusion and robert m chanock antigenic relationships among human mycoplasmas were studied by complement  fixation and agar gel diffusion techniques four recognized human species mycoplasma hominis type 1 m hominis type 2 m salivarium and m fermentans were antigenically distinct in these tests in addition m pneumoniae eaton agent the etiological agent of cold agglutinin  positive atypical pneumonia was different from these four species although these species were distinct evidence of shared antigenic components was obtained in complement fixation and agar gel diffusion tests since rabbits were immunized with mycoplasmas grown in rabbit muscle infu  sion broth supplemented with rabbit serum or in the case of m pneumoniae with infected chick embryo lung suspension the possibility that the heterologous reactions resulted from antibody to growth medium components could be excluded four recent mycoplasma isolates from the oro  pharynx were analyzed and three were shown to be closely related to m hominis type 1 and the fourth was closely related to m salivarium although the recent isolates could not be dis  tinguished from the related prototype human species by complement fixation differences could be detected by the agar gel diffusion technique
MED	mammalian cell cultures contaminated with pleuropneumonia like organisms ii effect of pplo on cell morphology in established monolayer cultures the occurrence of cytopathogenic changes in monolayer cultures of pplo contaminated mammalian cells has been shown to be related to deficiency of arginine in the medium the same effects were seen when the cell culture medium was depleted by pplo prior to application to pplo free cell cultures even though viable pplo were no longer present the fact that the same picture resulted in the absence of pplo when either arginine or glucose were omitted from the medium would indicate that while the defi  ciency created under the conditions described was specific the cellular changes could as well be the result of omission or depletion of other mam  malian cell growth requirements the importance of surveillance of cell lines for the presence of pplo to avoid misinterpretation of cytopathogenic effects was stressed
MED	suppression of rous sarcoma virus growth in tissue cultures by mycoplasma orale an agent which produced cell destruction in human diploid and chick embryo fibroblasts was isolated from wi 26 strain of human diploid fibroblasts and shown to be a mycoplasma the multiplication of rous sarcoma virus rsv and rous associated virus rav was inhibited in wi 26 wi 38 and chick embryo fibroblasts infected with this mycoplasma the mycoplasma isolate designated strain 941 reacted strongly in the complement fixation test with antiserum to mycoplasma orale ch19299 an isolate obtained from the human oral cavity the cytopathic effect of mycoplasma strain 941 could be eliminated by growing the mycoplasma on an artificial agar medium before inoculation into chick embryo fibroblasts serial passage in chick embryo fibroblasts restored the cytopathogenicity of the agar grown mycoplasma however growth of rsv and rav was inhibited by both the tissue culture grown and the agar grown 941 strain and also by the ch19299 strain which did not produce any cytopathic effect
MED	a method for direct demonstration of pleuropneumonia like organisms in cultured cells direct microscopic observation of pleuropneumonia like organisms pplo in cell cultures is easily accomplished follow  ing hypotonic treatment air drying and staining with orcein a rapid technique using fl human amnion cells inoculated with su  pernatant from suspected cultures is de  scribed the demonstration of pplo con  tamination of 30 cell lines by this rapid method was in complete agreement with re  sults of pplo agar techniques
MED	a fatal septicemic disease of infant puppies caused by cytopathogenic organisms with characteristics of mycoplasma pathogenic organisms were iso  lated from 2 outbreaks of a fatal septicemic disease of infant puppies and from dog kidney cells that degenerated spontaneously the iso  lates were indistinguishable serologically and possessed characteristics of mycoplasma the pathogenic organisms were cytopathogenic for dog kidney cell cultures and in inoculated puppies produced pathological changes that resembled those seen in natural cases le  sions consisted principally of necrosis and hemorrhage the isolates were culturally and serologically distinct from recognized canine mycoplasma species
MED	chromosome changes in pplo infected fl human amnion cells characteristic chromosome changes were observed in pplo infected fl human amnion cells these changes included a gradual reduction in chromosome numbers increase in chromosome aberrations and the appearance of 3 new varieties although some of the aberrations appeared early after infec  tion most changes developed slowly over a period of several months
MED	studies on mycoplasma pneumoniae infection in sweden sera from 107 cases of pneumonia and 132 cases of milder respiratory infection were examined by the cf test against m pneumoniae antigen thirty five patients with pneumonia and 2 patients with bronchitis had serologic evidence of m pneumoniae infection all cases which had a significant antibody rise with the cf test also showed a corresponding rise with the fluorescent antibody test m pneumoniae was isolated from 10 of 18 serologically positive cases cold agglutinins were demon  strated in 17 of 37 cases 46 per cent with m pneumoniae infection m pneumoniae infections occurred during all seasons of the year and were most common in older children and young adults the clinical features of the cases with m pneumoniae infection in this study re  semble those described in similar investigations in other countries
MED	spontane genetische veranderungen am zellstamm l earle the chromosomal constitution of a clone of the cell strain l was studied by repeated chromosomal analyses within 2 years there resulted the stability of the cellular clone with regard to the tested feature for the duration of about one year the maximal number of chromosomes amounted to 60 64 in later tests a spon  taneous doubling of the chromosomal number maximum 120 chromosomes was ascertained the cause of this phenomenon could not yet be cleared up this new chromosomal pattern remained unchanged in the subsequent examination period of 6 months as was proved by these observations under the present cultivation conditions cell populations can be retained stabile in vitro for a certain period the defined substances however still imply unknown factors which may have a mutagenous effect so that sudden changes of cell populations may result the respective physiological features are hardly known as yet
MED	chromosome changes in human diploid cell cultures infected with mycoplasma this communication shows that mycoplasma may also change cell chromosomes and therefore emphasizes the need for caution in interpreting experimental results without adequately testing for the presence of mycoplasma chromosome damage similar to that described here has been induced by viruses in cell cultures and in blood cul  tures chromosomal abnormalities have also been reported in blood cultures and bone marrow from leukaemic patients
MED	evaluation of tylosin in preventing egg transmission of mycoplasma gallisepticum in chickens the inoculation of mycoplasma gallisepticum infective yolk into the left posterior thoracic air sac of laying chickens resulted in an infection which produced a rate of egg infection satisfactory for experimental purposes culturing of all live embryonating eggs as well as all dead and infertile eggs was necessary to determine the rate of egg infection tylosin either injected subcutaneously administered in the drinking water or employed in an egg dipping solution greatly reduced but did not completely eliminate egg infection in the 3 egg dipping trials only 11 isolates of m gallisepticum were ob  tained from 2329 tylosin dipped eggs compared to 400 isolates from 2984 control eggs
MED	epidemiology of mycoplasma pneumoniae infection in families and ruth mcmahan the transmission and clinical manifestations of in  fection with mycoplasma pneumoniae were studied in 114 families in which there was a case of atypical pneumonia m pneumoniae was isolated from a throat culture of the index pneumonia patient in 36 of these families trans  mission to other family members occurred in 23 of the 36 families in these 23 families 84 of the children and 41 of the adults were infected the index cases are included of the total 59 patients with family contact infections 42 had lower respiratory tract symptoms 6 had pharyngitis alone 9 all children were asympto  matic and 2 had probably unrelated symptoms the time intervals between cases within a family suggested a median incubation period of 23 days treatment with tetracycline seemed neither to cure the symptoms com  pletely nor to abolish the carrier state that often lasted one to three months
MED	case of salpingitis due to pleuro pneumonalike organisms a case of acute salpingitis following a diagnostic curettage and aspiration of the pouch of douglas is described this case was resistant to penicillin and streptomycin therapy a pure culture of pleuropneu  monia like organisms pplo grew from pus removed from the secon  dary pyosalpinx by aspiration these organisms were sensitive to tetra  cycline which cured the adnexal infection no pplo were found in the vaginal discharge pplo have frequently been isolated from the vaginae of healthy and infected women however only 9 cases of pelvic inflammatory disease with a pure culture of pplo have been reported the possibi  lity that these growths of pplo in the internal genitalia followed the use of antibiotic therapy is discussed infection with pplo should be considered when pelvic inflam  matory disease proves resistant to the common antibiotics
MED	the serological differentiation of mycoplasma strains pleuro  pneumonia like organisms from various sources a complement fixation test with rabbit antisera was used to differentiate 82 cultures of mycoplasma from man mammalian cell cultures laboratory rats and mice cattle goats poultry embryonated eggs and sewage seventeen serotypes were distinguished 5 from man 1 from mammalian cell cultures 4 from rats and mice 4 from cattle and goats 2 from poultry and one saprophytic most of these corresponded to recognized species of mycoplasma but 1 of human origin represented by 1 strain navel and 1 from tissue cultures 5 strains may represent new species r38 one of the serotypes from rats could be distinguished from the species m arthritidis but is probably an antigenic variant rather than a distinct species two species hitherto recognized as distinct m arthritidis and m hominis type 2 could not be distinguished and appear to constitute a single species these findings illustrate the necessity from the viewpoint of taxonomy of comparing mycoplasma strains by serological methods the serotypes of human and animal origin were largely host specific exceptions were the inclusion of m arthritidis from rats and m hominis type 2 from man in a single serotype the finding of a bovine organism among the strains isolated from goats and of a saprophytic strain in a rat in relation to the aetiology of disease in man and animals the isolation of an endogenous mycoplasma from embryonated eggs used to passage infective material illustrates the importance of identifying these organisms serologically the demonstration of mixed mycoplasma infections in lesions in two rats shows the necessity of adequately purifying all cultures of mycoplasma before examination
MED	spiramycin in the treatment of experimental mycoplasmosis in day old chicks and turkey poults day old chicks and turkey poults experimentally infected with m gallisepticum have been treated at the time of infection with spiramycin administered by subcutaneous injection or drinking water medication a dose of 100 mg kg bodyweight by subcutaneous injection or an 0 04 per cent concentration in the drinking water continuously for three days eliminated the infection in most of the birds which remained free of air sac lesions and did not react to the slide agg  lutination or haemagglutination inhibition tests
MED	further studies of agents isolated from tissue cultures inoculated with human leukaemic bone marrow d a woods mycoplasmas were isolated from tissue cultures inoculated with bone marrow from leukaemic patients all cultures which showed a cytopathic effect contained mycoplasmas there was no evidence of mycoplasmas in control cultures the mycoplasmas isolated seemed biologically and serologic  ally to be of one strain which was different from any previously reported as being isolated from human sources although there was some relationship to a rodent mycoplasma m pulmonis mycoplasmas cannot readily be distinguished from viruses electron microscopically the relationship of mycoplasmas to leukaemia is not yet clear
MED	microbiological studies of reiters disease attempts were made to demonstrate viruses and pplo in body fluids and synovial tissues of patients with various rheumatic diseases all attempts to demonstrate viruses were negative pplo were looked for in 499 specimens from 114 patients with rheumatic and non rheumatic diseases whereas these organisms were readily isolated from genito  urinary specimens they were found in none of 31 synovial fluid specimens they could not be grown from synovial tissue biopsies of patients with rheumatoid arthritis ankylosing spondylitis gout gonococcal arthritis psoriatic arthritis traumatic arthritis or arthritis accompanying ulcerative colitis but they were present in one and possibly in two of eight synovial tissue specimens from patients with reiters disease complement fixation tests were negative in nine patients with reiters disease including the two from whose synovial tissues pplo were thought to have been isolated
MED	recovery of a pleuropneumonia like organism p p l o from the genitalia of the female albino rat the genital organs of seventy seven nonproductive breeder female rats were examined grossly and histologically and bacteriological cultures of the uterus and ovaries were made three of the seventy seven animals showed a purulent salpingitis and oophoritis a pleuropneumonia like organism was isolated from the uterus and ovaries of 29 of the animals examined the cultures obtained from the genitalia were compared with the p p l o isolated from the middle ears of some of these same animals and the two appeared to be identical intraperitoneal injection of the p p l o cultures into young rats and mice produced oophoritis and salpingitis in the mice but not in the rats
MED	chronic respiratory disease in mice and rats chronic respiratory disease crd in both mice and rats embraces two separate entities namely infectious catarrh caused by mycoplasmas pleuropneumonia like organisms and enzootic bronchiectasis by a virus the two syndromes are discussed in regard to their etiology pathologic manifestations and transmission particular attention is paid to the relation of mycoplasmas to infectious catarrh the morphologic and cultural characteristics of the catarrhal types of these organisms are considered from the standpoint of differential diagnosis the importance of crd in the maintenance of breeding colonies and in the use of animals for experimental purposes is stressed methods for the establishment of specific pathogen free colonies as a means of control are briefly outlined together with observations on a cesarean derived line of swiss mice
MED	further observations of the lymphomas of african children during 1963 cytopathogenic filtrable agents were frequently encountered in cultures of embryonic human kidney cells following their inoculation with supernatant fluids from primary human amnion cultures which had previously been exposed to extracts of tumors and other specimens from east african children with malignant lymphomas of the kind described by burkitt and others the results seemed noteworthy because they suggested an intimate association between the agents and the disease and also because of the nature of the isolations which involved two phenomena an initial induction of a peculiar spindling and twisting of the amnion cells fig 1 and subsequently destructive changes in kidney cells inoculated with fluid from such altered amnion cultures the direct inoculation of embryonic kidney cells with extracts of tumors or bone marrow never caused cytopathogenic effects nor did the isolated transmissible agents have the capacity to induce the amnion lesions nevertheless the two effects were closely associated and clearly related to the specimens the cytopathogenic agents were later cultivated on protein rich media and found to have the characteristics of mycoplasma they failed to induce tumors in a variety of animals and serologic tests in which they served as antigen gave suggestive but inconclusive evidence of a relationship to the disease the mycoplasma also failed to induce the amnion lesions caused by the specimens
MED	mycoplasma species of man at present six distinct species of mycoplasmas are known to infect man certain biological and ecological properties of these agents have been defined one species m pneumoniae has been definitely shown to be an important respiratory  tract pathogen and another species m hominis type 1 may play a role in respiratory tract and genital tract disease
MED	pleuropneumonia like organisms despite their small size the pplo carry the full complement of the chemical com  pounds and enzymes contained in larger bacteria and in cells they contain both dna and rna and in their independent metabolism they are essentially like other free living cells in contrast to the viruses which have no independent metabolism outside the living host cell several strains of pplo have been cultivated from the mucous membranes of apparently normal human subjects espe  cially from the respiratory and urinary tracts until recently however definite evidence of the association between the pplo and clear  ly defined clinical disease in the human sub  ject was lacking in 1962 it became evident that the so called eaton virus originally isolated by eaton and his associates in 1944 from patients with primary atypical pneu  monia was in reality a pleuropneumonia like organism typical pplo colonies are pro  duced on a cell free agar medium which is enriched by the addition of blood serum or yeast a number of strains of pplo has now been identified and in recognition of their unique characteristics they have been classi  fied in a separate order the mycoplasmatales genus mycoplasma
MED	problems of disease of parathyroid glands if biochemical tests indicate unequivocally that there is a functioning parathyroid tumour usually an adenoma its removal will relieve symptoms and prevent any further damage to organs such as the kidneys in 80 per cent of such cases the operation is not particularly difficult to anyone with experience of thyroid surgery the tumour is seldom of great size usually less than half an inch in diameter but a careful search in the expected position in close apposition to the posterior surface of the thyroid lobes will usually reveal it such adenomata are usually more brown in colour than the normal yellow gland but in some 20 per cent of cases one or more of the glands may be aberrant or possibly absent and super  numerary glands may be present it is usually one of the lower pair of glands which occupies an ectopic position and as i explained in the outline of the embryological development it may accompany the thymus into the mediasti  num rather a vast area in which to seek a small tumour such an exploration cannot be lightly undertaken but if the evidence is indisputable the burden must be shouldered it is correct policy i believe first to carry out a thorough exploration of the neck and if this proves un  availing to inspect the mediastinum through a sternum splitting incision some two weeks later rather than completing this major undertaking at one session
MED	the age factor in experimental hypertension of the dca type in rats rats aged 25 and 86 days were sensibilised by unilateral nephrectomy and a week later were given 1 1 mg 100 g dca every third day for 6 weeks and a 1 nacl solution to drink the younger rats reacted with a greater increase in blood pressure more so male rats hypertrophy of the heart and kidneys and mortality and supression of growth were also all more evident in the younger age group only male rats given the steroid hormone starting from day 25 showed permanent suppression of growth
MED	response of a serum glycoprotein to tissue injury and necrosis 1 the response to necrosis hyperplasia and tumour growth a serum glycoprotein of the rat underwent a 20 fold increase during 15 days growth of the walker tumour and this increase was not affected when the rats were treated with terramycin the protein increased at the same or a greater rate when rats were subjected to ischaemic necrosis of one kidney or of two  thirds of the liver boiled kidney tissue on the other hand had little effect upon the protein response and kidney hyperplasia had none it is suggested that this protein increase is a response to substances liberated from damaged or necrotic cells
MED	the natural history of autoimmune disease in nzb mice a comparison with the pattern of human autoimmune manifestations all mice of the nzb bl strain spon  taneously develop serological and pathological evidence of autoimmune dis  ease during adult life the nzb bl strain was developed by dr marianne bielschow  sky in dunedin new zealand by inbreed  ing from an outbred colony of mixed coat color several inbred strains  nzb nzc nzo nzw nzy and others have been evolved in dunedin from the original col  ony evidence for autoimmune disease in the nzb strain was first reported by bielschowsky helyer and howie who found evidence of an autoimmune hemo  lytic anemia the dunedin group used the presence of agglutinins for ficin treated red cells as the index of the disease
MED	the remaining kidney in irradiated survivors of wilmss tumor the intravenous urograms of 10 patients who had survived 5 years after irradiation for wilmss tumor were studied for kidney size and configuration the diseased kidney had been removed by nephrectomy the remaining kidneys had been sub  jected to varying doses of ionizing radia  tion at the time the area of the diseased kidney was irradiated in none was there evidence of atrophy all were within the range of expected normal size and most of them were enlarged
MED	cellular proliferation and deoxyribonucleic acid synthesis in compensating kidneys of mice and the effect of food and water restriction compensatory enlargement of the kid  ney occurred after unilateral nephrectomy in mice fourteen days after the removal of one kidney the surviving renal tissue 6 weighed 23 per cent more than single kid  neys from sham operated animals the hyperplastic response of the cortex on the second postoperative day was 8 times greater than that seen in the same zone of kidneys from sham operated animals by 10 days after surgery the mitotic index of the cortex returned to control values the outer medulla also underwent hyperplasia but only on the second day following unilateral nephrectomy was the increase significant an increase in mitotic activity was found in the inner medulla of surviving kidneys but it was not statistically signifi  cant both starvation for 48 hours and water restriction for 60 hours prevented the hyper  plastic responses in the remaining kidneys 2 days after unilateral nephrectomy when water was given 48 hours after unilateral nephrectomy after 60 hours of water restriction significant increases in mitotic activity were noted in the cortex of remain  ing kidneys on the fourth and fifth post  operative days however even after free access to food was allowed after 48 hours without food no significant increase in mitotic frequency of the remaining kidney was found deoxyribonucleic acid synthesis in con  trol kidneys of mice was highest in the cor  tex and lowest in the inner medulla as revealed by radioautographic studies fol  lowing the injection of tritiated thymidine two days following removal of one kidney the labeling index of the cortex of remaining kidneys increased 3 fold no statistically significant increases of deoxyribonucleic acid synthesis were noted in either the outer or inner medullary regions of the remaining kidneys
MED	compensatory renal enlargement hypertrophy versus hyperplasia after unilateral nephrectomy in the mouse the compensatory growth of the remaining kidney is characterized by an increase in rna and protein synthesis within the first hour dna synthesis remains un  changed for about 18 hours and then rises to a maximum at 48 hours by the end of the fifth day when dna synthesis has passed its peak and is in decline cellular hyperplasia has accounted for only one fourth of the increase in kidney weight thus it is shown that cell hypertrophy is both the primary and the predominant response in the early phase of compen  satory renal enlargement
MED	cell proliferation in experimental hydronephrosis and compensatory renal hyperplasia mitosis counts and autoradiographic counts of nuclei labeled with tritiated thymidine were made in the renal cortex of male rats in which the left ureter was ligated these were compared with corresponding counts in the remaining kidney after left nephrectomy and in sham  operated controls 24 48 and 72 hours after operation the cortex of the kidney on the obstructed side showed a greater number of tritium  labeled nuclei and mitotic figures than in the kidney undergoing com  pensatory hyperplasia epithelial and interstitial cells responded simul  taneously on the obstructed side whereas in the remaining kidney after nephrectomy the epithelial response preceded a slight interstitial re  sponse by 48 hours the contralateral kidney in rats subjected to ureteral ligation showed no response we concluded that the early response of increased dna synthesis and cell division in the obstructed kidney was not mediated by humoral factors it was localized and probably had a different mechanism than the proliferative response occurring in compensatory renal hyperplasia
MED	renal factors in the pathogenesis of hypertension renal arteriography and other modern diagnostic procedures have provided the means of establishing a close relationship between high blood pressure and renovascular disease many of these cases are amenable to surgical cure at the present time there is no single test for the definitive diagnosis of renal hypertension careful and intensive studies are mandatory in the selection of cases suitable for surgery since hypertension has many etiologic factors and involves many complex and sometimes obscure mechanisms aortography intravenous urography and split function tests are among the most important methods for definitive diagnosis and for the planning of appropriate surgical procedures at operation the most commonly observed cause of renal arterial con  striction in the elderly is atherosclerosis whereas in younger patients it is hyperplasia of the intimal and muscular coats of the renal artery and its branches renovascular surgery may require a variety of technical procedures in the successful cases there is a striking and permanent reduction in blood pressure the accuracy of blood pressure readings is emphasized since hypertension is usually discovered for the first time during the course of a routine physical examination
MED	cell proliferation in compensatory renal growth rats with one kidney removed showed a progressive increase in weight of the remaining kidney over a six week period autoradiographic and radiochemical studies with 3h thymidine indicated that the increase in new kidney cell formation was maximal forty eight to seventy two hours after unilateral nephrectomy this early response was chiefly due to the production of new cells by the renal cortical tubules normal rates of tubule cell turnover were achieved two weeks after operation the glomerular tufts contained fewer new cells and their peak production was delayed to the one week period with a slow decline thereafter rats forty eight hours after unilateral nephrectomy were chosen as a model to study the effect of various substances on the magnitude of new cell formation the number of dna synthesising cells in the stimulated kidney was reduced by treatment with hydrocortisone acth 9 10 dimethyl 1 2 benzanthracene and 1 2 benzanthracene the numbers were increased by the administration of deoxycorticosterone and aldosterone
MED	effects of adrenalectomy on the parathyroids in nephrectomized rats rat parathyroids were studied both after nephrectomy and after com  bined nephrectomy and adrenalectomy as early as 24 hours after nephrectomy there were morphological indications of increased para  thyroid activity in the form of increased glandular volume and enlarged cell nuclei the corresponding changes after combined nephrectomy and adrenalectomy were less marked and the total serum calcium was higher than after nephrectomy only these observations suggest that the adrenals could induce a change in calcium homeostasis opposite to that of the parathyroids
MED	pathogenesis of polycystic kidneys microdissection confirms our previous de  scription of an uncommon variety of poly  cystic kidney found only in the newborn periods it is characterized by symmetrical enlargement caused by saccular or cylindri  cal increase in size of all collecting tubules the number and relative length of different generations of collecting tubules are normal nephrons are present in normal numbers and their attachment to collecting tubules is normal the pattern of the nephrons is nor  mal except for minimal localized areas of dilatation interstitial connective tissue is not increased intrahepatic bile ducts are in  variably cystic siblings may be affected we believe that in such kidneys the be  havior of the ampullae of the branches of the ureteral bud is normal and that secondary hyperplasia of the interstitial portions of the branches is responsible for the greatly in  creased renal size
MED	concurrence of hyperplasia and neoplasia of the parathyroid glands the concurrence of parathyroid hyperplasia and neoplasia in a group of six patients is re  ported two patients had long standing renal disease with azotemia and hyperphosphatemia in both hypercalcemia developed while they were under observation and they were found to have parathyroid adenomas as well as hyper  plasia of the other glands a third patient followed an apparently similar course one pa  tient with primary hyperparathyroidism due to a large mediastinal adenoma displayed hyper  plasia of other glands in association with moder  ate renal insufficiency two patients with pri  mary generalized parathyroid hyperplasia were found to have superimposed neoplastic lesions multiple adenomatous nodules in one adenocar  cinoma in the other these observations add new dimensions to the diagnosis and therapy of parathyroid disorders they indicate the necessity of examining all four parathyroid areas at time of surgery they also emphasize that hypercalcemia developing in patients with chronic renal disease is a manifesta  tion of autonomous parathyroid function
MED	experimentelle nierenvergroberung nach unilateraler nephrektomie bei ratten untersuchungen mit 3h thymidin in this paper it is attempted to clarify certain questions as to the mechanism of compensatory renal hypertrophy by means of histological cytological and autoradiographical examinations in nephrectomy experiments on young and grown rats based on the results of this investigation the process of compensatory renal hypertrophy must be imagined as follows as early as two hours after unilateral nephrectomy a distinct increase of the mitosis index without a simultaneous increase in dna synthesizing cells was observed in the remaining kidney it is assumed that a cell division of polyploid cells is involved which were in a prolonged premitotic rest phase after a latent period of 48 hours the dna synthesizing cells and dividing cells start to increase the maximum of the regenerative processes is reached between the 3rd and 4th day after nephrectomy twenty days after unilateral nephrectomy the regenerative processes are largely concluded all tubule sections participate in the compensatory renal hypertrophy although the regenerative processes are most marked in the central section one cannot speak of the development of an actual indifference zone in the regenerating kidney in young test animals compensatory renal hypertrophy is determined more by mitotic cell division in older test animals more by polyploidization processes the results of these investigations provide no certain indications for the assumption that amitotic nuclear divisions play a major part in compensatory renal hypertrophy proliferation processes which in extent and localization run parallel to the regeneration of the parenchyma are also observed in the cells of the connective tissue of the renal vessels
MED	abscopal effects of whole body x irradiation on compensatory hypertrophy of the rat kidney the weight and dna content of normal growing i e intact and hypertrophying i e following uninephrectomy rat kidneys were obtained from several hundred sprague dawley white rats the effect of whole body x irradiation with 500 rad and local irradiation to the kidney with 1000 rad was then determined by following the rate and degree of hypertrophy and the dna content of the kidney when calculated on the basis of body surface area a constant ratio of kidney weight and of kidney dna was found in the normal non  hypertrophying kidneys of 5 12 week old rats after 21 days of hypertrophy these values increased approximately 50 per cent over normal in rats 4 6 weeks old at the time of nephrectomy for animals 6 14 weeks old at the time of nephrectomy the corresponding increase was only about 20 per cent following uninephrectomy and x irradiation with 1000 rad to the exteriorized remaining kidney 4 week old rats whose bodies were lead shielded during irradiation showed no body weight growth retardation no significant difference in the dna content of the kidney and a small but significant decrease in weight increment of the hypertrophying kidney after 21 days rats exposed to 500 rad of x rays with the kidney shielded during irradiation when compared with nonirradiated controls showed body weight growth retardation a reduction in the dna content of the kidney and a reduction in the amount of kidney hypertrophy 21 days following uninephrectomy a still greater inhibition of both kidney compensatory hypertrophy and the increase in dna content of the kidney occurred after 500 rad whole body irradiation food restriction in nonirradiated 4 week old rats resulting in body weight growth retardation elicited a marked reduction in kidney weight and in dna content of the hypertrophying kidney 21 days after uninephrectomy it is concluded that the reduction in kidney hypertrophy following whole body x irradiation with 500 rad is due in some measure to an abscopal or indirect effect secondary to decreased body weight
MED	radiation effects renal enlargement in the mouse three hours following unilateral nephrectomy weanling female cf 1 mice were subjected to local abdominal or total body exposure to either 500 or 600 r other groups were given 1350 r to half the abdomen with and without prior nephrectomy signifi  cant decreases in renal weight gain compared to controls were obtained in the 600 r total body group and in the locally irradiated ani  mals given 1350 r when the renal weight changes are compared on the basis of the ratio of renal weight to body weight in per cent an increase from 64 to 95 is seen in animals subjected to nephrectomy alone the final value in all of the irradiated and nephrectomized groups was similar ranging from 93 to 1 0 the results suggest that irradiation in these dose ranges does not exert a direct inhibitory effect on renal weight increase but it limits body weight gain which influences kidney weight
MED	renal hyperplasia and neoplasia in rats given dimethylnitrosamine multiple foci of hyperplasia and neoplasia were induced in the kidney of rats that had been dosed orally with dimethylnitrosamine the younger rats and the male sex had a greater incidence of renal tumors the hyperplastic or neoplastic lesions were classified into two groups on the basis of their histogenesis namely that of tubular epithelial origin and that of interstitial cell origin dimethylnitrosamine is recommended as a useful chemical compound for the study of renal carcinogenesis
MED	the role of age and x irradiation on kidney function in the mouse female mouse kidneys show a decline with respect to age in the ability to concentrate the urine during a 24 hour water fast x irradiation early in life has no measurable long term effect on this process kidney cortex slices of old female mice can concentrate p aminohippuric acid against a concentration gradient equally as well as slices from young mice there is no loss in this ability by cortex slices from young or old female x irradiated mice it is uncertain whether compensatory renal hypertrophy after unilateral nephrectomy declines with age in nonirradiated mice x irradiation does cause a reduction in the degree of compensatory renal hypertrophy in the aging mouse this reduction may represent a loss in the ability of kidney cells to undergo cell division the administration of testosterone propionate to old mice during compen  satory renal hypertrophy results in an increased hypertrophy the increase is relatively the same for irradiated and nonirradiated mice indicating the lack of a long term effect of x irradiation to reduce the ability of a target organ to respond to a hormone the over all conclusion of this study with respect to radiation induced aging is that x irradiation of the female swiss mouse early in life does not have a pronounced effect on kidney function late in life but may have a long  term effect on those processes concerned with cell division
MED	hyperaldosteronism hyperplasia of the juxtaglomerular complex normal blood pressure and dwarfism report of a case a patient with the syndrome of hyperal  dosteronism hyperplasia of the juxtaglo  merular complex dwarfism and normal blood pressure is reported in detail in this patient the aldosterone secretion rate in  creased significantly and the serum potas  sium rose slightly with sodium depriva  tion with a low sodium diet urinary sodi  um fell to zero spironolactone with a low  sodium diet raised serum potassium to nor  mal infusion of albumin however resul  ted in a rapid increase in serum potassium and a fall in aldosterone secretion rate the unique features in this patient are the re  sponse to albumin and the lowering of uri  nary sodium to zero in response to a low  sodium intake in all other essentials the case resembles the two previously reported cases treatment by subtotal adrenalecto  my was not curative
MED	the juxtaglomerular cells of the kidney and the zona glomerulosa of the adrenal cortex in the sodium losing and the hypertensive forms of virilizing adrenal hyperplasia pathological and biochemical observations are presented in two cases of virilizing ad  renal hyperplasia one of the sodium losing type and the other of the hypertensive type examination of the kidneys revealed hyper  trophy of the juxtaglomerular cells in the case exhibiting excessive sodium loss the adrenal cortex showed hypertrophy of the zona glomerulosa it is hypothesized that the chronic state of sodium loss caused changes in the intravascular compartment which led to compensatory activity of the juxtaglomerular cells with resultant stimula  tion of the zona glomerulosa examination of the hypertensive case known to involve a different enzyme defi  cit showed hypertrophy of the zona glom  erulosa without hypertrophy of the juxta  glomerular cells the intrinsic overproduc  tion of sodium retaining steroids associated with the genetic defect in this clinical form could account for both the hypertension and the absence of hypertrophy of the juxta  glomerular apparatus
MED	studies on eperythrozoon infection in sheep the intravenous inoculation of blood from sheep in the parasi  taemic stage of eperythrozoon infection produced detectable parasitaemia in recipient sheep within 7 days the parasitaemia lasted from 3 to 12 weeks and was accompanied by anaemia and occasionally by icterus no other symptoms developed and in a controlled experiment on hoggs there was no significant difference in weight gain between infected and control animals a concurrent attack of tick borne fever led to the disappearance of eperythrozoon from the circulating blood it is suggested that this phenomenon may be caused by the pyrexia the incubation period following the inoculation of infected blood in ten 3 to 4 week old lambs varied from 3 to 6 weeks in eight of these animals the symptoms were less severe than in adult sheep but the two smallest lambs developed a profound anaemia and failed to gain weight culture of the organism on sheep blood agar or on sheep kidney monolayers was unsuccessful as was the attempted transmission of the infection to mice the transference of keds and lice from infected to uninfected sheep failed to transmit the infection but a sheep was infected by the intravenous inoculation of ground up lice from an infected animal the only characteristic histopathological changes in infected sheep were lymphoid hyperplasia of the malphigian corpuscles in the spleen and deposition of haemosiderin in the cells of the proximal convoluted tubules in the kidney cortex
MED	age differences in cellular proliferation in rat kidneys the hyperplastic response to unilateral ne  phrectomy after 48 hours in the cortex and medulla of the remaining kidneys of weanling and young adult rats was studied by means of autoradiography tritiated thymidine which is destined exclusively for nucleoprotein synthe  sis was administered to 11 control and 11 ex  perimental rats 4 hours prior to sacrifice labeled tubular cells were rare in control tissues especially in medulla where the per  centages did not differ greatly for the two age groups in the cortex of controls such cells were three times more frequent for weanling rats than for adults significant increases in per  centages of labeled cells over control levels were found in both regions of the remaining kidneys for both age groups the percentage of increase was greater in medulla than in cortex and most pronounced in medulla of the young adult rats
MED	phospholipids of the sexual segment of the kidney of the indian house lizard hemidactylus flaviviridis ruppell the indian house lizard hemidactylus flaviviridis breeds seas  onally in a sexually mature male lizard from october to may of the following year the secondary and tertiary collecting tubules of the kidney are hypertrophied forming the sexual seg  ment the development of the sexual segment is synchronous with the testicular cycle and maximum development occurs during the period when the testes are spermatogenically active the sex  ual segment is not developed in the females in any season of the year it is completely regressed in males during sexual quiescence june and july injection of 4 0 mg of testosterone propionate over two weeks stimulated the regressed sexual segment to hyper  trophy in males during quiescence and also in females the apical portions of the cells of the sexual segment are loaded with granular secretions which are stained with bakers acid hae  matein and phosphomolybdic acid stannous chloride indicating the presence of choline   containing phospholipids the composi  tion of the phospholipids of the sexual segment which is a unique feature of the lizards and snakes is unknown this preliminary communication describes the isolation and quantitative estimation of phospholipids present in the sexual segment of the indian house lizard hemidactylus flaviviridis ruppell
MED	on the erythropoietic effect of different tissue suspensions the stimulating effect on erythropoiesis of regenerated liver and hyper  trophic kidney tissue after partial hepatectomy and unilateral nephrectomy respectively was studied in the rat by means of the erythrocyte count haemo  globin determination reticulocyte count and 59fe utilization the reticulocyte count and 59fe utilization increased significantly after treatment with normal liver and renal tissue and more strongly after regenerated liver and hypertrophic kidney tissue the same effect was seen after treatment with the sera of rats which had undergone partial hepatectomy or unilateral nephrectomy
MED	hemihypertrophy and medullary sponge kidney congenital hemihypertrophy is an over  growth of one side of the body which is associated with an asymmetry beyond the ex  pected range it is to be distinguished from hemiatrophy in which atrophy or withering of one half of the body has occurred usually be  cause of neurological lesions this condition of hemihypertrophy though rare is very frequently associated with other congenital abnormalities these include several in the urogenital tract such as hypospadias cryptorchidism unilateral renal hypertrophy and an increased incidence of wilms tumour
MED	chemical aspects of compensatory renal hypertrophy the effect of unilateral nephrectomy on the size and composition of the remaining kidney has been investigated in rats in normal rats the right kidney is on the average significantly heavier than the left and has a higher total content of dna and rna the 2 kidneys have almost identical ratios of rna dna and protein dna after unilateral nephrectomy the surviving kidney increases steadily in wet and dry weight for the 1st 4 days after the operation this is accompanied by a much slower increase in total dna content and by a dramatic increase in rna dna ratio the rna dna ratio in kidney is also affected by diet being higher on a high protein than on a low protein intake moreover the rise in rna dna ratio that follows unilateral nephrectomy is greater in animals fed a high protein diet the changes in kidney weight and in total contents of dna rna protein and lipid phosphorus resulting from the feeding of a high protein diet were found to be of approximately the same magnitude as those in the remaining kidney 4 days after unilateral nephrectomy the rna dna and protein dna ratios are also greater in rats fed a diet containing 10 urea but the increase is much less than that in the remaining kidney after unilateral nephrectomy
MED	the antidiuretic mechanism of hydrochlorothia  zide in the treatment of diabetes insipidus the changes in water and electro  lyte balance during hydrochlorothiazide therapy in 2 patients with vasopressin  deficient diabetes insipidus were studi  ed in 1 case under fixed daily so  dium intake the urinary sodium excre  tion markedly increased on the first day of treatment but the urinary volume began to fall on the second day and per  sisted low for 3 days after discontinua  tion of the drug in the other case the urinary volume markedly decreased when the daily sodium intake was strict  ly limited it further decreased on hydrochlorothiazide therapy but after sodium intake was restored it returned to the pretreatment level despite con  tinued use of the drug the antidiuretic action of hydro  chlorothiazide in the treatment of dia  betes insipidus is believed to be related to the sodium depletion state of the body brought about by increased output or decreased intake of sodium sodium and water reabsorption in the proximal convoluted tubules in the kidney in  creases and the amount of glomerular filtrate reaching the distal convoluted tubules decreases thus the final urinary volume falls
MED	the action of oral diuretics in diabetes insipidus chronic administration of chlorothiazide and other thiazide analogues in diabetes insipidus results in a striking reduction in urinary volume with increase in urinary osmolality this curious antidiuretic action was first described by crawford kennedy 1959 and though it has since been widely confirmed in both the pituitary and nephrogenic forms of the disease its precise mechanism remains obscure a number of investigators have sought to explain the phenom  enon entirely on the basis of the renal actions of these drugs earley orloff 1962 goodman carter 1962 whilst others have contended that abatement of polyuria may be secondary to a central effect of the thiazides in decreasing thirst robson lambie 1962 skadhauge 1963 over the past two years we have conducted detailed in patient studies of the action of various diuretic drugs of the thiazide and other series in a group of 7 patients with pituitary diabetes insipidus
MED	investigations into the thiazide induced antidiuresis in patients with diabetes insipidus plasma sodium osmolality and serum chloride together with creatinine clear  ance were studied before and during thiazide treatment of 7 patients with diabetes insipidus the diuresis was reduced by 28 39 the urine osmolality was increased by 7 128 an average decrease in plasma sodium of 4 meq i in plasma osmolality of 21 mosm kg and in serum chloride of 8 meq i was observed only in one pa  tient was the creatinine clearance re  duced significantly the thirst feeling was reduced even from the first day of treat  ment the diuresis was not minimal until the third to fourth day if the diuresis was corrected for the extra electrolyte ex  cretion initiated by the thiazide the antidiuresis was found to be operating to the full extent even on the first day of treatment it is concluded that the antidiuresis is mainly secondary to the natriuresis and to a certain degree due to a decreased thirst  feeling but there seems also to be a direct renal action involving at least a reduc  tion of the glomerular filtration rate a pronounced antidiuresis was found by a water deprivation test after thiazide treatment in one patient
MED	salt and water the antidiuretic effect of thiazides is thus the result of the induced sodium deficit the fall in serum osmolality may be contributory by reducing thirst as depletion of body sodium will be self limiting the major hazard to the use of thiazides is potassium depletion treatment of patients with vasopressin insufficiency type of diabetes insipidus with thiazides is only indicated for those who are intolerant of hormone replace  ment in nephrogenic diabetes insipidus thiazides have a more important therapeutic application
MED	nephrogenic diabetes insipidus chlorothiazide has been found of value in establishing and maintaining adequate hydra  tion in some patients its exact mechanism of action is not known the antidiuretic effects of chlorothiazide and its analogues have been studied in six patients with ndi two of whom were infants less than six months of age dehydrated infants showed a dramatic response to treatment with those unable to achieve an optimal fluid intake prior to treat  ment the initial beneficial response was asso  ciated with an increased fluid intake follow  ing this initial antidiuretic response a vari  able degree of escape or resistance to the action of the drug commonly occurred de  spite the unpredictability of a prolonged anti  diuretic response a therapeutic trial of chloro  thiazide in ndi seems warranted if diet alone is not sufficient to maintain hydration it must be remembered however that this drug is po  tentially toxic
MED	fluid and electrolyte metabolism in nephrogenic diabetes insipidus the body fluid volumes have been fol  lowed in two infants with nephrogenic diabetes insipidus without treatment both patients had a low extracellular fluid volume ecv and a normal to low  normal total body water tbw following thiazide therapy case 1 and during a fluid deprivation test case 2 a further reduction of ecv and tbw was found untreated both patients revealed a se  vere hypernatriemia without any increase in the urinary aldosterone excretion the first patient had a cerebral atro  phy and a rightsided hydronephrosis a higher diuresis and a lower concentration capacity was found on this side the patient was treated continuously with thiazide when an ordinary house diet was given this drug could only maintain normal electrolytemia in combination with spirolactone a considerable increase in height and psychic development took place during this combined treatment it is noted that nephrogenic diabetes insipidus may be present in infants with unexplained fever and vomiting in the absence of polydipsia and polyuria the urine may even be hypertonic
MED	diuretics in pediatric practice clinical notes and comments with the development of more and more potent oral diuretics in recent years these drugs which were once looked upon as being of only limited usefulness in pediatrics are now receiving clinical application they per  mit a new approach to the management of edematous states that most of them can be given orally is a significant advantage par  ticularly when coupled with their relative lack of toxicity although the number of patients in the pediatric age range who require these agents is relatively small they are valuable adjuncts in the management of chronic renal disease refractory heart failure and hyper  tension this discussion reviews their pharma  cology and clinical indications
MED	the role of aldosterone and vasopressin in the postural changes in renal excretion in normal subjects and patients with idiopathic edema the effects of the upright posture leisurely walking for 2 hours on half  hourly urine volume and excretion of sodium and creatinine were studied in 13 normal subjects and 13 patients with idiopathic edema while they drank 150 or 300 ml of 0 14 per cent sodium chloride solution every half hour when the 2 hours of walking were compared with a preceding recumbent period of 4 hours both groups were found to show a significant antidiuresis upright the administration of ethanol during the last half hour of recumbency abolished the fall in urine flow and in free water clear  ance during the first hour of walking in the normal subjects and significantly re  duced this fall in the patients with edema sodium excretion in the normal subjects was slightly but not significantly lower when upright than when recum  bent but in the edematous patients was significantly lower when upright and fell progressively over the 2 hour period ad  ministration of spironolactone or d  amphetamine increased sodium excretion during recumbency in both groups but increased sodium excretion upright only in the edematous patients to equal that of the normal subjects creatinine excre  tion was not changed in either group by posture or drug therapy similar studies were performed on 5 patients with un  treated diabetes insipidus and on 6 pa  tients with adrenal insufficiency treated with hydrocortisone alone lack of al  dosterone in adrenal insufficiency did not increase the amount of sodium ex  creted above that of normal subjects in recumbency and did not prevent the oc  currence of significant sodium retention in the upright posture however lack of adh in diabetes insipidus delayed the antidiuresis upright for 30 minutes the results indicate that adh release is probably responsible for the reduction in urine volume during the first 30 min  utes after assuming the upright posture but not thereafter the excessive magni  tude of the orthostatic antidiuresis in idiopathic edema probably results from a cause other than adh release since it is not completely overcome by ethanol reduced na excretion during 2 hours in the upright posture can occur in the absence of circulating aldosterone but the abnormal magnitude of the na re  tention in the patients with idiopathic edema probably results from hyperal  dosteronism
MED	the use and mode of action of ethacrynic acid in nephrogenic diabetes insipidus the use of diuretic agents in the treatment of nephrogenic diabetes insipidus had been re  ported to result in decreased urine volume and decreased clearance of free water a study of the use of ethacrynic acid a potent saluretic agent was instituted in patients with nephrogenic diabetes insipidus in an attempt to achieve a significant antidiuretic response while allowing a liberal sodium diet intravenous ethacrynic acid resulted in de  creased urine volume decreased clearance of free water and decreased rpf and gfr prolonged oral administration of ethacrynic acid promoted a significant antidiuretic re  sponse when the daily sodium intake was limited to 60 meq the effect of ethacrynic acid on renal function potassium and chlo  ride excretion and uric acid metabolism are discussed
MED	the treatment of pituitary responsive diabetes insipidus in evaluating therapy in diabetes insipidus it is important to note we are altering only ten per cent of the reabsorption function of the kidney the kidney function in a case of diabetes insipidus is as efficient in its activity as are biological tests the purpose of therapy is patient convenience economy and normal function in society the diabetes insipidus itself does not alter the life span however secondary factors may introduce it into a health problem lysyl 8 vasopressin nasal spray is effective offers a maximum of conve  nience and has produced no untoward reactions it is as expected ineffective in the treatment of extrapituitary pituitary unresponsive diabetes insipidus
MED	antidiuretic effect of hydrochlorothiazide in diabetes insipidus and chiuan lu 12 cases of diabetes insipidus were studied during hydrochlorothia  zide therapy under a fixed diet the symptoms blood pressure urinary volume blood and urinary electrolytes plasma volume electrocardiogram and hypertonic saline intravenous drip test were compared before and after treat  ment a daily dose of 100 150 mg brought down the urinary volume to about 50 of the pretreatment value the initial antidiuretic effect was noted 8 hours after medication and the maximal effect after the fourth or fifth day owing to the kaluretic action of the drug 2 4 gm of potassium salt was also given each day satisfactory re  sults were obtained with dietary sodium ion at not more than 200 meq daily but ingestion of excessive table salt fre  quently diminished or even destroyed the therapeutic effect the physical signs blood pres  sure and ecg were essentially un  changed and the plasma volumes were altered after treatment the hyper  tonic saline test was improved in some of the patients low salt syndrome was fre  quently encountered as the therapy continued over 1 month but this and even secondary failure could be pre  vented by timely use of intermittent or alternative regimen the therapeutic mechanism indications and side effects of the drug were briefly discussed the drug might possibly act through the mechanism of salt depletion contraction of extracel  lular fluid volume and decrease of renal glomerular filtrate and in consequence urinary volume decreases and thirst is alleviated
MED	the effect of hydrochlorothiazide on water intake and plasma osmolality in diabetes insipidus in the rat a fall in plasma osmolality accompanied the reduction of urine volume in rats with hypothalamic diabetes insipidus given hydrochlorothiazide and an otherwise normal diet the plasma concentration was not reduced with a high sodium intake although urine volume still fell normal rats and hypo  thalamic obese rats increased their water turnover after hydrochlorothiazide yet their plasma concentration fell moreover the antidiuretic response to vasopressin which is purely renal was also accompanied by plasma dilution although it is self evident that rats which drink less are less thirsty the reduction in thirst after hydrochlorothiazide may not be a direct result of the change in plasma osmolality as previously shown in patients kennedy and hill 1963 a high sodium intake increased free water clearance in diabetes insipidus but did not interfere with the reduction of polyuria by hydrochlorothiazide whereas a high potassium intake reduced free water clearance and prevented any effect of the drug on urine volume
MED	antidiuretic properties of chlorothiazide in diabetes insipidus dogs chlorothiazide was found to decrease urine volume and increase urine con  centration in diabetes insipidus dogs there was no change in gfr rpf tmpah plasma volume extracellular fluid or total body water the one con  sistent altered function was a decrease in free water clearance diazoxide and mercuhydrin were not antidiuretic it is believed that the antidiuretic action is dependent on the chlorothiazide induced saluresis although the mechanism of this antidiuresis has not been clearly de  fined it seems best explained by postu  lating a decrease in filtrate reaching the distal nephron giving a decreased final urine volume coupled with inhibition of solute reabsorption in the distal tubule preventing the selective reabsorption of solute in the distal tubule that is nor  mally seen accounting for the increase in urine concentration the possible role of the mineralocorticoids in the antidiuretic response to chlorothiazide therapy was investigated in diabetes in  sipidus and adrenalectomized dogs ad  ministration of sodium retaining steroids to diabetes insipidus dogs did not re  produce the urinary changes associated with chlorothiazide therapy in addition the antidiuretic response to chlorothia  zide was not altered by adrenalectomy or spironolactone administration there  fore the presence of the sodium retain  ing steroids are not essential for the anti  diuretic response of chlorothiazide in diabetes insipidus
MED	stable strontium in human bone geographical and age differences in the united kingdom and their correlation with levels of strontium 90 a re assessment has been made of published data of other workers on sr and 90sr in human bone in different parts of great britain the mean ratio of stable sr to ca in adult human bones ranged from 240 to 475ug g extreme values were found even as close as 40 miles apart carlisle v westmorland perinatal levels of stable sr were correlated with adult levels an estimate of placental discrimination may be derived from the ratio perinatal level adult level of about 0 7 the concentration of stable sr in bones of children from 2 to 5 years old or more was not demonstrably different from that of adults except in one area carlisle with the striking exception of london and south east england the change from perinatal to adult levels occurred in the 2nd year of life there was no particular change during the first 9 months or so in london and south east england the pattern of change with age was quite different there was a progressive rise in sr level from shortly after birth to the end of the 1st year by which time adult levels were reached it is concluded that geographical differences need to be taken into account when making physiological deductions about turnover of bone salt from changes with age in the level of stable sr when children in the south east of england and the rest of the united kingdom were compared there seemed to be a broad inverse correlation between levels of stable sr and of 90sr detailed analysis of perinatal results from one area suggested that the level of stable sr in bone was somewhat higher in summer than in winter and somewhat higher in anatomically normal babies than in babies dying with gross congenital defects 90sr showed the seasonal change only
MED	fibrin and thrombosis in the central nervous system in children with particular reference to congenital hydrocephalus while rare metabolic and degenerative diseases of the central nervous system in children are reported at great length the much commoner diseases relating to vascular incidents are rarely discussed only those aspects of disease of the central nervous system related to thrombosis and the deposition of fibrin will be discussed here diseases related to general vasculitis and aneurysm are omitted the conditions discussed here fall into two main categories first the presence of thrombosis in small blood vessels or in the large superficial veins draining the brain and second the deposition of fibrin either in the ventricles or on the membranes overlying the brain in association with thrombotic lesions haemorrhage or infiltration
MED	hydrocephalus due to unrecognized cerebellar astrocytoma treated by ventriculoatrial shunt for four years a case of a 9 year old girl is presented in whom prolonged palliation of signs of increased intracranial pressure presumed to be due to aqueductal obstruction was achieved by means of a ventriculoatrial shunt four years after placement of the shunt signs of a cerebellar mass became apparent the neoplasm a cystic astrocytoma was subsequently totally resected and the shunt was removed air studies demonstrating diminution of ventricular size within this four year period are compared
MED	hydrocephalus the problem of hydrocephalus formerly a hopeless one has in recent years begun to yield to clinical research the indications for the new forms of treatment and their drawbacks are clearly delineated in this discussion by a leading authority in the field
MED	a case of unilateral hydrocephalus secondary to occlusion of one foramen of monro a unique case of unilateral obstructive hydro  cephalus secondary to occlusion of one foramen of monro by gliomatosis in a 3 day old infant is reported
MED	calcification within congenital aneurysms of the vein of galen thirty one cases of aneurysm of the vein of galen had been reported previ  ously calcification within the wall of the aneurysm was visible on plain skull roent  genograms in 6 of this number the present communication describes an additional case in which calcification of the aneurysm was discovered at the age of 9 years the youngest patient heretofore reported
MED	ventriculo venous shunts for infantile hydrocephalus a review of 48 hydrocephalic patients treated with atrioventricular shunts during a 5 year period has been presented we have discussed function of the shunt complica  tions of the procedure and revisions neces  sitated by nonfunctioning the overall 75 per cent survival rate and 14 3 per cent in  fection rate is comparable to that in other series the major cause of death in our pa  tients has been infection our experience to date supports the ob  servation that spontaneous arrest of the hy  drocephalic process does not occur once a ventriculo venous shunt has been estab  lished meticulous introduction of a ventriculo  venous shunt appears to be the present treat  ment of choice for patients with severe hy  drocephalus results are only satisfactory when the patients are carefully followed and complications recognized and treated promptly
MED	congenital malformations of c n s it seems that only a small proportion of malformations of the central nervous system can be explained in simple genetical terms and that most are dependent to some extent at least on environmental factors the nature of these has yet to be determined dr williamson found that the maternal aunts uncles and cousins of her index cases of anencephalus and spina bifida were more frequently affected than the paternal relatives were she suggested that mothers of affected children had some genetic factor which modifies the intra  uterine environment and thus predisposes the embryo to these malformations such a hypothesis opens up interesting possibilities but before accepting it one would have to be satisfied that the higher incidence in maternal relatives is not merely due to the fact that the history is obtained in most cases from the mother
MED	experimental studies on cerebrospinal fluid flow a mixed suspension of kaolin and lyco  podium was injected into the cisterna magna of dogs blockade of csf space was produced successfully in 63 of 75 dogs in 48 of the 63 ventricular dilatation of more than interme  diate degree was observed in these hydrocephalic dogs experimental shunting was performed either between the lateral ventricle and the lumbar cistern or be  tween the unilateral lateral ventricle and the contralateral cerebral subarachnoid space uni  directional steady csf flow averaged 0 15 ml per hour in the cases of the former shunting and the flow averaged 0 25 ml per hour in the cases of the latter shunting csf flow rate from the ventricle toward the cerebral subarachnoid space was larger when intraventricular pressure was higher this in  crease in flow rate parallel to increasing pres  sure probably results from an increase in csf absorption there seems to be an upper limit of the flow rate as the pressure is raised transient reflux of csf flow was induced by jugular or abdominal compression following intravenous administration of hy  pertonic solutions csf flow rate decreased parallel to the fall of csf pressure and re  gained the original value as the pressure was recovered when the pressure fell as low as 50 mm of water the flow almost stopped
MED	the dandy walker syndrome the dandy walker syndrome is a specific morbid entity in which the fourth ventricle is grossly dilated and there is a congenital malformation of the cerebellar vermis it is nearly always associated with atresia of the foramen of magendie and in many cases with atresia of the foramina of luschka also the lateral and third ventricles are usually dilated figure 1 illustrates a specimen of the condition most cases present in infancy but others are discovered in childhood and in adult life the oldest patient recorded to have had this anomaly was aged 59 years the first recognized case was published by dandy and blackfen in 1914 but the best early description of the condition is that of taggart and walker 1944 who concluded that the cerebellar lesions were consequent upon the atresia of the foramen of magendie in 1954 benda proposed the term dandy walker syndrome
MED	a probable epidemic of congenital hydrocephalus in 1940 1941 a peak in the incidence of congenital hydrocephalus in 1940 41 is described reasons are given for believing it to be a genuine phenomenon though it is too late to find the cause epidemics of malformations are to be detected promptly only if the incidence of malformations in a defined population is studied continuously and for some epidemics the population studied must be very large indeed
MED	functional craniology an aid in interpreting roentgenograms of the skull analysis of the form of the skull is facilitated by considering it to be composed of a number of functional components for the roentgenologists purposes division into the facial or somatic skeleton and the neu  ral skeleton is valuable as is the recognition of three functionally separate portions within each calvarial bone the inner table the diploe and the outer table the base of the skull is the only por  tion that is preformed in cartilage this ac  counts for the unusual appearance of the skull in achondroplasia in addition the base apparently is more closely related to facial and general somatic growth than to neural growth calvarial bone forms directly from membrane within the cerebral capsule consequently the size and shape of the cal  varia directly reflect the form of the grow  ing neural mass the inner table of the calvaria at all ages is intimately related to the dura mater and directly reflects the form of the dura mater consequently the inner table re  flects the form of the arachnoid mater and usually of the brain as well the outer table of the calvaria serves not only to protect the brain but also to anchor many of the intrinsic and extrinsic muscles of the skull its form particularly in thick skulled mammals such as the pig is determined more by the demands of these muscles and of the scalp than by the form of the brain the principal function of the diploe is to form a lightweight yet rigid separation of the two osseous tables in addition it serves as a site of hematopoiesis for this reason it may tend to a specific volume at a given age the calvarial sutures oppose separa  tion of the bones of the calvaria while al  lowing relative motion between them when the calvarial bones are passively car  ried apart with the expanding cerebral cap  sule by the growth of the neural mass their areas are increased by the deposition of bone in the suture margins the sutures however do not function as epiphyses and have no innate growth potential removal of a suture does not disturb final skull form because the calvaria represents ossi  fication of the cerebral capsule it is small when the neural mass is small the de  formity of the skull and the secondary changes that occur in the air sinuses and the diploe can be explained in terms of the functional cranial components the op  posite changes occur when the neural mass is abnormally large the correlation between skull size and intelligence is only fair the presence of a brain of distinctly abnormal size however may be inferred from plain roentgeno  grams of the skull premature closure of the cranial su  tures may be due to an abnormal form of the cranial base and possibly of the primi  tive chondrocranium that precedes it the abnormality is mediated through the dural fiber tracts that underlie the major cal  varial sutures
MED	hydrocephalus changes in formation and absorption of cerebrospinal fluid within the cerebral ventricles formation flow and absorption of cerebrospinal fluid were measured in normal and progressively hydrocephalic dogs by steady state studies during ventricular per  fusion the formation of cerebrospinal fluid was found to be constant independent of hydrostatic pressure and unaffected by the development of hydrocephalus the normal dog produced 0 016 ml cerebrospinal fluid min in the lateral ventricles 0 011 ml cere  brospinal fluid min in the 4th ventricle and 0 20 ml cerebrospinal fluid min in the sub  arachnoid space the intraventricular forma  tion of fluid was calculated to be 0 24 ml cerebrospinal fluid min gm of choroid plexus and 0 3x10 3 ml cerebrospinal fluid min cm 2 of ependymal surface absorption of cerebrospinal fluid was found to take place within the ventricles as well as in the subarachnoid spaces the re  sistance to absorption of cerebrospinal fluid in the normal ventricle was much higher than in the hydrocephalic ventricle the decrease in resistance occurred as the ventricular volume increased and the ependyma became flattened so that in chronic hydrocephalus the resistance was not significantly different than in the normal dog the theory of re  stricted diffusion was applied to the data to calculate the diffusive permeabilities of crea  tinine and urea and from this the mean pore radius within the ventricle using formation of cerebrospinal fluid and data on absorption the hydrocephalic animals could not be distinguished from the normal with sufficient accuracy to suggest using this as a clinical test the reason for this is that intraventricular pressure has always been considered as if it were constant when in fact it is changing constantly the problem of ventricular enlargement concerns the ability of the craniospinal contents to adjust to and absorb the small but very rapid changes in intracranial contents that occur with each beat of the pulse
MED	dural sinus pressure in normal and hydrocephalic dogs simultaneous measurement of cerebro  spinal fluid pressure csfp and venous pressure in the anterior ssvp and poste  rior sagittal sinus tvp has demonstrated that in the normal dog the mean pressures are related as follows csfp ssvp tvp the statistical relationship between the pres  sures has shown a poor correlation of ssvp and tvp with changes in csfp on the other hand in the hydrocephalic dog ssvp rises to meet csfp and is related to fluid pressure in a 1 1 fashion this could be ex  pected to cause a non venting of acute changes of csfp and a decrease in fluid ab  sorption it is postulated that the mechanism of ssvp elevation is a partial occlusion of the sinus
MED	intraventricular papilloma a case of intraventricular papilloma of the left lateral ventricle is reported craniotomy was performed and removal of the tumor was ac  complished without incident the literature is reviewed an unusual although perhaps relatively unim  portant observation in the reported case was that for four or five days postoperatively the patient a 17 month old female kept her head tilted to the right but at the time she left the hospital she was holding it erect and unsupported and was sustaining weight satisfactorily on both feet
MED	five year comparative study of hydrocephalus in children with and without operation 113 cases on the basis of a 5 year study of 113 hy  drocephalic children of whom 65 were oper  ated on early with ventriculo atrial shunting and 48 were not operated on all of them hav  ing been studied periodically in a similar manner to determine mortality morbidity intelligence and related factors the follow  ing conclusions are justified the program in which shunting opera  tions were done apparently gives significant advantages to the children over the program in which no shunting operations were done based on life table data projected from birth to 10 years survival 61 8 per cent as compared to 22 2 per cent number of competent children i q of 75 or better 33 8 per cent vs 5 5 per cent number of noncompetitive children i q below 75 27 6 per cent vs 16 7 per cent the major cause of death and morbid  ity in both groups is infection in the operative group morbidity associated with the shunting procedure is related to obstruction of the shunt and septicemia the early occlusions show a correlation with abnormal inflammatory type of spinal fluid being shunted into the blood stream the late obstructions are associated with mechanical breakage of the shunt or factors of growth causing retraction of the cardiac end from the atrium prompt re establishment of a functioning shunt has been possible in all instances periodic follow  up examinations irrespective of symptoms have proved invaluable in early recognition of malfunctioning shunts septicemia usually required removal of the shunt from the program of periodic evalua  tions including bubble ventriculograms studies of clearance of risa and psycho  logical testings correlations showed intellectual ability seemed associated with width of cerebral mantle width of cerebral mantle in hydrocepha  lus decreases with ventricular pressures of 120 or over it increases with pres  sures less than this prolonged shunting of cerebrospinal fluid can give dramatic increase in width of cerebral mantle apparently irrespective of basic etiology of the hydrocephalus intellectual capacity could not be cor  related with the basic etiology of the hydrocephalus but did correlate in  versely with duration of increased in  tracranial pressure the many etiologies of hydrocephalus require large numbers of patients in each group for thorough evaluation factors favoring such studies should be carried out in medical centers where appropriate disciplines can study in depth prevention should be the ultimate goal in the operative group only 1 patient compensated his hydrocephalic process and no single patient demonstrated arrest of or recovery from the basic hydrocephalus pro  ducing process in spite of numerous attempts to demonstrate this this might imply a necessity for life long shunting of cerebro  spinal fluid in these cases
MED	hydrocephalus any present day definition of hydrocephalus is very loose the authors would rather adopt the concept that hydrocephalus is an abnormal condition characterized by excessive amount of cerebrospi  nal fluid with or without enlarge  ment of the head the most common cause of hydrocephalus is arachnoiditis fol  lowed by congenital anomalies a neoplasm is a rare cause the ideal surgical procedure is the placement of a ventriculo  atrial shunt using either pudenz or halter valves where these valves cannot be availed of the choice is between a conservative waiting with medical support and ventricular tapping from the older surgical shunting procedures like ventriculo peritoneal choroidoplex  ectomy thecal fimbia subarach  noid ureteral and others
MED	recognition and treatment of hydrocephalus following spontaneous subarachnoid hemorrhage eight adult patients with hydrocephalus secondary to spontaneous subarachnoid hem  orrhage have been presented with a discus  sion of diagnosis and treatment a number of possible mechanisms for the development of ventricular dilatation in this condition have been advanced and pathological data have been presented in 2 cases
MED	congenital malformations clinical and community considerations two of the most significant medical events of the century the epidemic of post rubella anomalies in australia during 1940 and 1941 and the pan  demic of thalidomide embryopathies in europe and elsewhere during 1960 and 1961 have demonstrated clearly the importance of monitoring programs to record the occurrence of congenital malformations at group for example hospital and community especially city levels the principle of report  ing malformations and utilizing the data for service programs or better still for prevention is not new but the methodical use of vital statistics in a scientifically constructed surveil  lance system is new so also is the joint endeavor on the part of clinicians public health workers and basic scien  tists to reconstruct an epidemiology of deformity on the basis of time place person distributions of malformations a primary need has been for stand  ardized methods of classifying and reporting congenital malformations
MED	the family history of spina bifida cystica the family histories of 722 infants who were born with spina bifida cystica were studied the index cases were referred for sur  gical treatment and were not selected in any way from the genetic point of view intensive inquiries were made to ob  tain a complete family pedigree including a prospective follow up of siblings born after the index case of 1 256 siblings 85 or 6 8 had gross malformation of the central nervous system spina bifida cystica in 54 anencephaly in 22 and uncomplicated hydrocephalus in 9 of 306 children born after the index case 25 8 or 1 in 12 were affected there was a progressive increase in multiple cases in the family with increasing family size in sibships of five or more mul  tiple cases occurred in 24 1 in 118 families cases of gross malfor  mation of the central nervous system were known to have occurred among members of the family other than siblings cases oc  curred in three generations it is possible that spina bifida cystica might be a recessively inherited condition
MED	pulmonary vascular changes complicating ventriculovascular shunting for hydrocephalus a patient is described in whom pulmonary hypertension and cor pulmonale were noted 3 years after placement of a ventriculovascular shunting apparatus for treatment of hypdrocephalus in addition the histologic sections of lung tissue obtained from 65 patients with hy  drocephalus who died at various intervals following placement of a ventriculovascular shunting apparatus were reviewed with regard to vas  cular alterations a high incidence of old and multiple pulmonary vascular lesions was found in this group compared to the incidence in control subjects this difference can be attributed to the operative procedure the lesions in postmortem material were not widespread and did not suggest the diagnosis of pulmonary hypertension on purely histologic grounds
MED	etiology of trypan blue induced antenatal hydrocephalus in the albino rat wistar strain albino rats were injected with 1 cm3 of a 1 solution of trypan blue three types of dye were used matheson coleman and bell chroma gesellschaft and a highly purified sample the dyes were injected on days 6 7 and 8 of gestation fetuses were excised from days 16 through 20 fixed decalcified where necessary embedded in paraffin serially sectioned and stained newborn young were treated similarly chroma gesellschaft trypan blue was without reproductive or teratogenic effect at the above doses increasing the dose did not increase the teratogenicity but did yield a decrease in litter size both matheson coleman and bell trypan blue and the purified sample were teratogenic the most frequent neural defect observed was hydrocephalus serial sections of the newborn hydrocephalics showed an occluded or extremely tenotic aqueduct of sylvius in 31 of 33 sectioned animals the fetuses collected from days 18 through 20 also had occluded or stenotic aqueducts if hydrocephalic aqueductal stenosis or occlusion was present in 17 day old fetuses but hydrocephalus was not conclusively demonstrated at this age sixteen day old fetuses did not have aqueductal occlusion in any of those examined but stenosis was evident it is concluded that the defect predisposing to hydrocephalus in the young of trypan blue treated rats of this strain is aqueductal stenosis or occlusion
MED	bilateral papilloma of the choroid plexus a rare case of bilateral papilloma of the choroid plexus in a five and a half year old hydrocephalic girl is pre  sented the tumor encountered at autopsy was not suspected during life the existing hydrocephalus being attributed to either cytomegalic inclusion disease or toxoplasmosis after post mortem examination it was evident that the hydrocephalus was due to two factors hypersecretion from the tumor itself and obstruction at the level of the sylvian aqueduct by a delicate tense translucent mem  brane an interesting and uncommon additional feature of this case was the presence within the choroidal papillo  ma of well formed haversian bone a plea is made for regularly considering papilloma of the choroid plexus in the differential diagnosis of hydro  cephalus in children for here early diagnosis and treat  ment might conceivably result in total cure
MED	the diagnosis of hydrocephalus the early diagnosis of hydrocephalus is imperative if definitive steps for its correction are to be effective transillumination is a fairly accurate procedure that may offer the earliest means of determining whether or not the infants head is enlarging however serial head measurements constitute the easiest and most accurate method for early detection of hydrocephalus charts of normal head size of full term and premature infants are available to aid the physician in evaluating any deviation from normal once the condition has been detected it is up to the neurosurgeon to determine the treatment plan the operative procedure most widely used for shunting the excessive cerebrospinal fluid is insertion of a spitz holter valve early detection and improved treatment methods will help prevent irreversible intellectual damage likely to develop if hydrocephalus continues unchecked
MED	infantile hydrocephalus and hematoma in the posterior fossa we have presented a case of hydrocephalus in an infant the basic cause being intracranial hemorrhage in the perinatal period surgical re  moval of a hematoma in the posterior fossa did not give permanent relief of the raised intracranial pressure a lumbar air study at this stage dis  closed information that the passage through the intracerebral cerebrospinal fluid pathways was normalized whereas the extracerebral ones still were occluded by arachnoiditis the condition necessitated a ventriculo atrial shunt
MED	urinary excretion of i131 diodrast injected intraventricularly in communicating hydrocephalus and aqueduct stenosis nine cases of expansive infantile hydro  cephalus were investigated by injecting small amounts of i131 diodrast intra  ventricularly urinary excretion of the tracer was determined during the first 4 5 hours after injection the cumulative excretion of diodrast from the c s f dif  fers in cases with communicating hydro  cephalus from those with stenosis of the aqueduct the investigation is rapid and easily performed and has not produced any side effects
MED	gastrointestinal ulceration and central nervous system lesions there is both a real and an apparent in  crease in the incidence of severe gastroin  testinal ulceration due to central nervous lesions some of this increased incidence reflects recently devised iatrogenic measures including new drugs and surgical therapy in adults cerebrovascular lesions are the commonest single cause of acute peptic ul  ceration found at autopsy in children we found 25 instances of upper gastrointestinal ulceration due to central nervous system le  sions in 1 750 autopsies two general ana  tomical categories could be recognized acute ulceration and malacias a variety of causative central nervous sys  tem lesions was responsible in these 25 cases the commonest being bacterial meningitis other causes were poliomyelitis brain tu  mor hydrocephalus etc theories of pathogenesis are presented more experience with both drug and surgical therapy is needed the recent development of local freezing techniques offers promise for reduction of mortality
MED	mansonia crassipes as the natural vector of filarioids plasmodium gallinaceum and other plasmodia of fowls in ceylon it would appear from these observations that m crassipes is the natural vector of p gallinaceum of fowls in ceylon and possibly of other species of plasmodium of fowls or of related avian hosts if one of the other plasmodia from m crassipes is in fact p lophurae then this will be the first record of p lophurae from this part of the world we are however not certain whether the fowl is the natural vertebrate host of p lophurae in ceylon we have seen crithidial forms in the midgut of engorged wild caught m crassipes this mosquito may therefore prove to be the vector of the trypanosome as well the trypanosome differs from trypanosoma gallinarum and t calmettei which have previously been reported from fowls
MED	filariasis in portuguese timor with observations on a new microfilaria found in man the results are described of an investigation into filariasis in portuguese timor two types of microfilariae were found in blood films one was wuchereria bancrofti and the other referred to as the timor microfilaria is probably a new species blood surveys showed that w bancrofti and the timor microfilaria were widely distributed in the territory but that infection rates were usually low clinical lesions were few and mild elephantiasis was confined to oedema of the lower limbs below the knee the timor microfilaria resembles that of brugia malayi in general staining reaction and appearance and in the possession of two nuclei in the terminal thread but differs in over all length in cephalic space ratio and in failure of the sheath to stain with giemsa it is nocturnally periodic it was rapidly removed from the peripheral blood by treatment with diethylcarbamazine citrate in daily doses of 9 3 13 3 mgm per kgm body weight or 3 3 5 0 mgm per kgm body weight for seven days only damaged fragments of adult female worms were recovered the timor microfilaria was not found in cats dogs or monkeys the vectors of filariasis in timor are still unknown
MED	dipetalonema obtusa mccoy 1936 comb n filarioidea onchocercidae in colombian primates with a description of the adult microfilaria obtusa mccoy 1936 was identified in the blood of 29 31 of 93 cebus capucinus and c albifrons from northern colombia but was not found in an additional 42 c apella and 99 saimiri sciurea from other areas in colombia the adult male and female recovered from the peri  esophageal connective tissue of the infected animals are described in detail dipetalonema obtusa mc  coy 1936 comb n resembles tetrapetalonema marmosetae faust 1935 but is smaller and the right spicule is complex not simple
MED	experimental onchocercal ocular lesions in the chimpanzee this is the first attempt to produce onchocercal eye lesions with microfilariae of o volvulus in the chimpanzee live microfilariae once in the anterior chamber of the eye could penetrate the an  gle of the anterior chamber the iris the ciliary body the choroid and the vitreous most of the microfilariae injected alive into the anterior chamber of the eyes of the chimpanzee died within a short time com  parison therefore could not be made be  tween the effects of live and dead micro  filariae microfilariae debris was demonstrated within giant cells for the first time subconjunctival and limbal infiltration with incipient pannus inflammation within the trabecular meshwork of the angle of the anterior chamber and extensive active iri  docyclitis were demonstrated in histologic sections although the conditions were clini  cally quiescent the posterior segment lesion of oncho  cercal chorioretinal degeneration could not be reproduced subcutaneous and intravenous injec  tions of worm extracts derived from human onchocercomas may have contributed to the onset of active choroiditis this sensitization alone without the intraocular injection of microfilariae had no effects on the eye various aspects of the pathogenesis of human onchocerciasis are discussed on the basis of present experimentation
MED	the occurence of dirofilaria magnilarvatum price and brugia sp in philippine monkeys of 356 macaca philippinensis examined three were found infected with dirofilaria magnilarvatum price 1959 one of these was infected also with a species of brugla both species showed a sub periodic type of microfilarial periodicity these observations suggest that philippine macaques may serve as reservoirs for sub periodic b malayi on palawan where high rates of infection have been found in people living in small villages in the forests mansonia bonneae was found naturally infected with third stage larvae of d magnilarvatum it is sug  gested that monkeys may serve as reservoirs for sub  periodic b malayi on the island of palawan where high rates of infection with this species have been observed in people living in small villages in the forest
MED	the filarial parasites of the eastern gorilla in the congo a survey for parasites has been undertaken in 20 mountain gorillas gorilla gorilla beringei from the eastern congo kivu province six full grown two males and four females three adolescents one male and two females and eleven young gorillas were examined some of them during several consecutive months nine autopsies were performed no protozoa were discovered in the blood plasmodium parasites which are common in gorillas and chimpanzees from west africa were never found in the eastern congo primates including ten other gorillas examined previously and some fifty chimpanzees severe diarrhoea with a balantidiasis picture developed in two young gorillas autopsy revealed however an intensive infection with oesophagostomum stephanostomum and resulting fatty degenera  tion of the liver oligotrichida belonging to the genus troglodytella were commonly found in the intestinal tract oesophagostomum stephanostomum eggs were consistently present in the stools of the gorillas and autoinfection caused the death of several young gorillas 4 to 6 weeks after their capture many microfilariae were found in the blood and the skin pre  liminary communications were published mentioning the existence of four different microfilariae in the blood of gorillas and of three others in the dermal layers of the skin after a detailed study seven species have been identified and described dipetalonema leopoldi d gorillae d vanhoofi d streptocercum microfilaria binucleata loa loa gorillae n subsp and onchocerca volvulus three of the worms described have so far been discovered only in gorilla gorilla namely dipetalonema leopoldi d gorillae and loa loa gorillae two of them were previously known from the chimpanzee namely d vanhoofi and microfilaria binucleata one species d strepto  cercum first discovered in man and later described from the chimpan  zee is now also known from gorilla gorilla onchocerca volvulus has been found in only one of the 20 gorillas examined gorilla gorilla beringei in eastern congo might become through close contact with man and his filarial vectors an abnormal or accidental host of d streptocercum and onchocerca volvulus or else might be considered as an original reservoir of these filarial parasites of man
MED	a pilot project for the control of filariasis in thailand in a village in kanjanadit district of surat thani province south thailand where a field station for filariasis studies had been established by the bangkok school of tropical medicine blood films were examined from 977 persons 95 5 per cent of the total population of 1 023 two thick films each of 20 c mm were prepared from each person and stained with giemsa it was found that 21 1 per cent of the people harboured microfilariae all brugia malayi elephantiasis was found in 5 3 per cent of the population microfilarial periodicity was studied in 25 persons in every case it was found to be markedly nocturnal the blood of 98 cats 52 dogs and two monkeys was also examined no b malayi larvae were recovered mosquitoes were caught and identified in an initial survey 4 557 mosquitoes were examined of which 568 were mansonia spp in 4 136 dissections b malayi larvae in stage ii were found in one m uniformis and in stage iii in another the infection rate for m uniformis was 0 6 per cent spraying with ddt was carried out in all the houses during the last phase of the investigation it resulted in a slight decline in the numbers and percentage of mansonia mosquitoes caught diethylcarbamazine was administered to as many of the villagers as possible in a dose of 5 mgm of the citrate salt per kgm body weight once weekly for six weeks eight hundred and eighty eight persons received the drug 86 8 per cent of the population considerable side effects were observed in nearly all microfilaria carriers blood examinations were repeated one month and again one year after cessation of the drug it was found that the proportion of microfilaria carriers had decreased from 21 1 per cent to 2 2 and 2 2 per cent respectively the filariasis infection rate from 26 1 per cent to 8 6 and 8 5 per cent and the mean microfilarial density of all films from 4 8 per 20 c mm blood to 0 48 and 0 12 larvae of b malayi were not found in mosquitoes dissected one month and one year after the mass therapy
MED	studies on loiasis in monkeys iv   experimental hybridization of the human and simian strains of loa in the cameroons rain forest there exist two strains of loa each apparently evolving in its own host vector complex duke and wijers 1958 the natural simian parasite which is found most abundantly in the drill mandrillus leucophaeus is characterized by the large somatic size of the adult worms and microfilariae and by its nocturnal microfilariae periodicity it is transmitted among the monkey population by the crepuscular canopy dwelling chrysops langi and c centurionis the natural human parasite has diurnally periodic microfilariae and is transmitted by the day biting anthropophilic c silacea and c dimidiata bombe form it can also be transmitted experimentally to the drill in which host the parasites are of small somatic size and maintain their diurnal periodicity as the two strains of contrasting periodicity can be maintained in drills it was decided to try cross mating them to produce hybrids the present paper describes the methods by which this was done records the characteristics of the hybrid parasites and suggests that when interbreeding the two strains segregate according to a simple mendelian pattern as regards periodicity and somatic size
MED	development of dirofilaria immitis in anopheles quadri  maculatus after exposure of the microfilariae to a freezing temperature blood samples containing dirofilaria immitis microfilariae were stored frozen for periods ranging from 24 hr to 4 months thawed at 38 1c and fed through an animal derived bandrode membrane to laboratory reared anopheles quadrimaculatus the microfilariae were capable of developing to the third or infective larval stage and migrating to the head and labium of the mosquito
MED	advances in filariasis especially concerning periodicity of microfilariae a review is given of some advances in our knowledge about filariasis during the past ten years it is urged that investigations should be continued on methods to facilitate the control of filariasis in large populations by means of diethylcarbamazine  e g incorporation of the compound in cooking salt as was done with chloroquine against malaria furthermore steps should be taken to protect young people against filariasis by systematic treatment in the schools in order to understand the cyclical disappearance of microfilariae from the peripheral blood and their accumulation in the lungs the movements of microfilariae in the pulmonary capillaries has been studied by cinematography apparently their accumulation in the lungs is not due to mechanical retention but perhaps they migrate round and round in the pre capillary network of arterioles the periodicity of microfilariae is best considered as a biological rhythm apparently the microfilariae have a circadian rhythm of their own which is entrained and synchronized by stimuli from the circadian rhythm of the host judging by experiments with monkeys containing microfilariae of edesonfilaria malayensis the most effective of these stimuli from the host seems to be the rhythmic variation of body temperature which occurs every 24 hours
MED	attempts to transmit wuchereria bancrofti to cats and to a toque monkey there are no records of the larval development of wuchereria bancrofti in experimental animals in attempts to transmit periodic w bancrofti to domestic cats and to a toque monkey we recovered from one of the cats an infective larva that had undergone some development this finding was reported in a preliminary note dissanaike and niles 1963 the present paper gives the experimental details and describes the larva
MED	the periodicity of microfilariae x the relation between the circadian temperature cycle of monkeys and the microfilarial cycle monkeys were used whose blood contained the microfilariae of edesonfilaria malayensis which has a nocturnal periodicity artificial lowering of the body temperature during the daytime caused the microfilaria count in the blood to rise and artificial raising of the body temperature during the night caused it to fall almost to zero i e inversion of the normal circadian temperature rhythm of the body was followed by inversion of the microfilarial rhythm the hypothesis is put forward that the circadian rhythm of the microfilariae of e malayensis but probably not of the microfilariae of some other species is entrained by the circadian rhythm of body temperature which thus provides the effective stimuli to which these microfilariae respond
MED	the periodicity of microfilariae ix transfusion of microfilariae edesonfilaria into monkeys at a different phase of the circadian rhythm this paper reports experiments in which microfilariae at one phase of their circadian rhythm were transfused into a host at another phase of the circadian rhythm in an attempt to analyse the relative importance of the rhythms inherent in the microfilariae and of those in the host for the production of the well known periodic migrations the experiments were performed with edesonfilaria malayensis yeh 1960 present in a macaca monkey from thailand
MED	biliary tract morphology and prognosis of biliary atresia in 86 infants who did not have extrahepatic hepatic ducts present observation after use of artificial bile ducts suggests that the presence of the gallbladder may be of good prognostic significance in biliary atresia there are 11 long term survivors as of october 1965 up to 8 1 4 years of age 100 months after use of artificial bile ducts in 86 babies a gallbladder was identified in 10 of the 11 infants other specific factors for this prolonged survival pattern in these infants with biliary atresia have not yet been identified although suggestive correlations among minimal hepatic fibrosis maximal bile ductule proliferations and the presence of the gallbladder were noted it is suspected that if any opportunity for long term survivals exists for infants to overcome the tragic occurrence of biliary atresia that the surgeon should avoid trauma to the hepatic pedicle we may be able to provide a guarded rather than a pessimistic prog  nosis when the gallbladder is found in the babies with biliary atresia
MED	current concepts in the management of congenital biliary atresia the current management of congenital biliary atresia at the university of cali  fornia los angeles is reviewed biliary enteric decompression was performed on 18 of the 27 patients eight of whom are presently alive 29 6 these figures are higher than the cure rate of 8 previously reported described recently five additional patients with extrahepatic atresia underwent biliary decompression by means of a hepatic lymphaticojejunostomy early diagnosis of biliary atresia is im  perative in order that any corrective sur  gery may be performed before advanced biliary cirrhosis develops
MED	congenital atresia of the extrahepatic bile ducts because congenital atresia of the extra  hepatic biliary tract is almost always fatal exception to this course becomes of interest the remarkable history of one such infant was reported in 1960 when he had attained the age of 2 1 2 years and after three opera  tions he was in good health developing nor  mally and free of jaundice since he is now 8 1 2 years of age has had two more opera  tions is still free of jaundice and is again in good health his further course since 1960 should be of interest
MED	neuroaxonal dystrophy in congenital biliary atresia neuroaxonal dystrophy has been described in 8 patients with congenital biliary atresia the characteristic changes include axonal dystrophy a mild loss of nerve cells and a variable degree of astrocytic reaction mainly in the gracile cuneate and trigeminal nerve nuclei in the medulla and rarely in other parts of the central nervous system the neuroaxonal dystrophy in these patients is remarkably similar to that in patients with prolonged mucoviscidosis and in experimental vitamin e deficient rats it is strongly suggested that the neuroaxonal dystrophy in these patients with congenital biliary atresia is a manifestation of prolonged vitamin e deficiency the neuroaxonal dystrophy in these patients is also similar to that seen in aging and bears resemblance to the axonal change encountered in a group of heredo degenerative diseases the various forms of hallervorden spatz disease the pathological similarity between these diverse conditions warrants further investigation as to the possible metabolic relationship between them
MED	extrahepatic biliary atresia comments on the frequency of potentially operable cases in a 10 year period 35 infants with extrahepatic biliary atresia were encountered twenty eight babies who were subjected to surgery and operative liver biopsy are discussed although an operable lesion was detected at laparotomy in only one baby 5 further potentially correctable lesions were discovered in the 14 necropsies performed review of the literature revealed that few authors have discussed necropsy findings and that confirmation of the diagnosis by liver biopsy has been neglected in many cases including some of those claimed as surgical cures it is concluded that the frequency of potentially operable forms of biliary atresia is not really known
MED	metabolism and excretion of c14 labeled bilirubin in children with biliary atresia and judson g randolph radioactive bilirubin was injected intravenously into 3 children with biliary atresia the isotope over a period of ten to fourteen days was recovered principally in the urine sixty per cent of the label in the urine was found to be in the form of bili  rubin distribution of the radioisotope was observed to be principally extravascular but not as in other forms of jaundice in the same distribution as albumin daily turnover of bilirubin was several times greater than the calculated normal daily production of bili  rubin this was assumed to be due to increased hemoglobin breakdown confirmed by survival studies of cr51 tagged red cells the serum half life of intra  venously administered radioactive bilirubin may have useful prognostic value in children with biliary atresia
MED	central regulation of enzyme activity and synthesis in embryonal and adult mammalian tissues activity of non specific hexokinase hk in soluble fraction and particularly in mitochondria of embryonal liver is much higher than in the adult rabbit it decreases in the prenatal period gradually approaching adulthood values postnatally fig 1 embryonal liver lacks specific glucokinase gk 1 2 although during the second half of embryonic development there occurs incretion of insulin known to induce gk synthesis in the liver of alloxan diabetic animals 3 4 activity of glucose 6 phosphate dehydrogenase g6p dh in soluble liver fraction is subject to quite similar changes during embryonic development
MED	ribonuclease activity in hepatic nuclei during development mammalian liver undergoes marked qualitative and quantitative changes during the development from the embryonic to the adult stage many of these events are associated with the derepression or repression of certain enzymes which may be related to specialized subcellular activity the involvement of ribonucleic acid in the transcription of the information from the genome into the construction of a finished protein molecule has prompted a study of biosynthesis of the rna during differentiation although considerable effort in this regard has been expended in amphibian1 5 and avian6 7 systems as well as in the sea urchin8 11 a paucity of literature exists with mammalian liver accordingly an investigation of the alterations in rna metabolism which occur during the development of the rat embryonic liver has been undertaken this report concerns the fluctuations in nuclear ribonuclease during hepatic development and some of the properties of the enzyme
MED	an electron microscopic study of developing gall bladder epithelium in the rabbit the gall bladder epithelium of the adult rabbit consists of two types of cells the first and more common type shows features associated with absorption notably microvilli limited pinocytosis some lysosomes and an elaboration of the lateral cell membrane and intercellular spaces the mitochondria are concentrated in a subapical band the second and more infrequent type is a dark rod shaped cell of unknown function but which may be a dehydrated epithelial cell foetal epithelial cells lack the functional adult characteristics the mito  chondria are uniformly distributed in addition they display basal granules and apical apocrine bullae epithelial cell damage and white cell infiltration occurs between 24 days after birth or just after just before birth some epithelial cells are very large and pale with smooth outlines others are more dense and display vigorous pinocytosis adult characteristics are acquired at or immediately after birth and pino  cytosis subsides it is believed that water resorption occurs before the functional changes which allow continuous passage of water into the circulation
MED	congenital anomalies of the cystic duct and phineas rabinovitch anomalies of the cystic duct of four differ  ent types are reported the characteris  tic anatomic appearance and embryonic development of each of these anomalies are described and the clinical and surgical significance discussed
MED	lesions of the liver in hereditary metabolic diseases whether the various cells of the liver both parenchymal and stromal receive genetic misinformation in all hereditary diseases caused by gene mutation is unknown but the metabolic capabilities of these several cell types are so diverse that it is not surprising that their involvement in many such diseases can be demonstrated by clinical pathological or bio  chemical methods repetitive abnormality of the liver has apparently not been defined for any disease caused by quantitative i e chromosomal gene anomaly whether produced by nondisjunction translocation or major deletion perhaps because relatively few such diseases have been described as a result the genetically determined disorders of the liver surveyed in this paper appear to be the result of conventional single gene abnormalities and to be transmitted in affected families by men  delian mechanisms
MED	acid catabolic enzyme activity in relation to accessory limb and cancer initiation in amphibia cathepsin and acid phosphatase were determined in livers and kidneys of adult rana pipiens and triturus viridescens organ specific and species  specific differences in distribution of these enzymes were found as well as considerable differences in the effect triton x 100 on the two enzymes a heterogeneous population of lysosomes in respect to enzyme content and stability is deduced we have found positive correlations between catheptic activity of the implant and host tissue dissociation and between acid phosphatase and inducibility as features of the phenomenon of implant induced accessory limb formation in urodeles further we have found a positive correlation between catheptic activity and resistance to virus induced renal adenocar  cinoma development in rana pipiens
MED	neonatology considerable progress has been made in the knowledge of bilirubin metabolism since the char  acterization of direct conjugated bilirubin as an ester glucuronide the metabolic pathway involved in this hepatic conjugation is now well established and has been the subject of excellent reviews by sherlock and billing sherlocks diagrammatic representations of biliru  bin metabolism fig 1 and of the possible mecha  nisms of jaundice fig 2 are reproduced here because they furnish a clear picture to serve as a reference point for the discussion to follow it is interesting to re examine current concepts of the etiology of physiologic jaundice with this dia  gram in mind jaundice may occur for a number of reasons described below
MED	red cell glucose 6 phosphate dehydrogenase deficiency  a newly recognized cause of neonatal jaundice and kernicterus in canada seven male newborns of chinese greek and italian origin presented with severe hemo  lytic jaundice due to red cell glucose 6  phosphate dehydrogenase g 6 pd defi  ciency in five the hemolysis was precipi  tated by inhalation of mothball vapours in the home kernicterus was evident upon admission in six infants and was fatal in four of these g 6 pd deficiency should be suspected as a cause of jaundice in all full term male infants of these ethnic groups the diag  nosis can be confirmed in any hospital by the methemoglobin reduction test in areas similar to toronto canada where these high risk ethnic groups prevail the follow  ing measures are recommended 1 detec  tion of g 6 pd deficient newborns by screening cord bloods of all infants of these ethnic groups 2 protection of affected infants from potentially hemolytic agents such as naphthalene certain vitamin k preparations and sulfonamides and 3 ob  servation of serum bilirubin levels to assess the need for exchange transfusion for hyper  bilirubinemia
MED	trisomy 17 18 syndrome with congenital extrahepatic biliary atresia and congenital amputation of the left foot the phenotypic characteristics of the 17 18 trisomy syndrome have been well described among the most recently docu  mented cases of this syndrome are those with findings of agenesis or aplasia of various bones of the forearm and hand in addition to the more classical symptoms we have recently studied a case of trisomy 17 18 syndrome with congenital absence of the left foot and congenital extrahepatic biliary atresia
MED	differentiation of explanted fragments of early chick blastoderm ii culture on protein deficient medium enriched with rna posterior fragments of head process blastoderms were cultured in vitro for two days on a protein deficient medium sup  plemented with various rnas after which they were grafted over the chorio allantoic membrane for eight to nine days pancreatic adult rna enhanced the development of the entodermal epi  thelium heart adult rna caused hyper  plasia of the epidermis with in some cases keratinized papillary projections brain embryonic rna produced a papillomatous epidermis with giant epi  dermal cysts that were keratinized and fibrillar as in feather formation liver embryonic rna had no vis  ible tissue modifications in the controls there was no keratini  zation nor papillary formation of the epi  dermis the epidermal cysts were very small unkeratinized and devoid of fibrillar organization the results are discussed in terms of relationships of proteins from brain mus  cle and skin
MED	the inhibition of cell aggregation by a pure serum protein the aggregation of embryonic chick and quail limb bud heart and liver cells in a shaker system has been investigated in order to elucidate the mechanism of cell adhesion a new method of assessing aggregation is described and evaluated this method involved measurements of aggregation kinetics it was found that the measured kinetics agree closely with flocculation kinetics which provides a direct quantitative measurement of adhesiveness in terms of the probability of an adhesion forming on contact between two cells using this technique it was confirmed that aggregation is inhibited at 1 2 c in the presence of serum but not in its absence the kinetics of aggregation in the presence of serum at 37 c the lack of inhibition of aggregation at 1 2 c by serum which has been conditioned by the presence of cells and the similar lack of inhibitory power of serum which has been pre treated with antiserum antibodies all suggest that serum contains a factor which inhibits aggregation until destroyed by cellular metabolism
MED	les icteres du nouveau ne en dehors de lincompatibilite foeto maternelle statistical data pulled off a study of 30 haemolytic neonatal icteri not linked to a foeto maternal incompatibility and of 200 non haemo  lytic neonatal icteri among this latter the two most important groups are the malformative icteri 69 cases and the neonatal hepatitis 109 cases the difficulties of the diagnosis frequently rencountered between these two groups clearly appear in the comparative statistical analysis of the clinical histological and evolutive data
MED	the immunological development of the human fetus the normal human fetus is said not to be engaged in the formation of immuno  globulins the immunoglobulins present in the serum of the fetus and the newborn are considered to be of maternal origin in favor of this opinion is the observation that directly after birth the serum of the newborn contains an appreciable amount of igg with gm groups identical with those of the mother 68 70 the level of the igg of the neonate decreases gradually during the first 3 months 3 27 71 which is generally explained by the catabolism of the maternal igg whereas the formation by the newborn infant is still inadequate to maintain the original level 16 27 the best evidence for the transplacental passage is the almost complete absence of igg in the serum of newborn infants from mothers with agammaglobulinemia 3 27 the transfer of the immunoglobulins appears to be a selective process 13 15 while igg is readily transferred there is little if any transfer of iga and igm as has been shown by ultracentrifugation and immunoelectrophoretic studies of the serum 12 16 19 20 and the analysis of maternally transferred antibodies 31 33 with more sensitive techniques such as the double diffusion test in agar or quantitative immunochemical techniques however minute amounts of both igm and iga have been detected in fetal blood as well as in cord blood from mature and immature neonates 12 19 20 23 26 since large molecules do not pass the placenta this may indicate that the trace amounts of igm originate in the fetus itself but transplacental passage has not been completely excluded the absence of immunoglobulin formation has been associated with the absence of plasma cells in the lymphoid tissues and bone marrow of the normal human fetus and the newborn it has been reported that these cells do not appear until a few weeks after birth 2 3 14 25 34 however in pathological conditions such as congenital syphilis and toxoplasmosis the human fetus has been found to respond to the antigenic stimulus with intrauterine formation of plasma cells after about the sixth month of gestation 24 25
MED	galactosemie congenitale this observation of a case of congenital galactosemia with a particular familial incidence gives the opportunity of a brief review on the subject of a certain point of view we must consider that galac  tosemia is much more frequent than we suppose that there are many severe cases with a reserved prognosis that even with very slight degree of galactosemia the disease must receive the most careful attention from the pediatrician
MED	postnatal changes in the portal circulation during foetal development a large portion of the oxygenated umbilical blood flows through the umbilical recess directly into both main portal branches accordingly these are exposed to the umbilical blood pressure and have a wide by contrast the trunk of the portal vein is narrow and there is probably only a small blood flow through it from the inactive digestive tract though the pressure in it is approximately the same as in the umbilical vein or perhaps somewhat higher immediately after birth the liver is deprived of the substantial umbilical blood flow the portal venous pressure falls to about one quarter of the umbilical venous pressure at birth however the pressure gradient between the portal veins and inferior vena cava remains constant
MED	pattern of serum transaminase activity in neonatal jaundice due to cytomegalic inclusion disease and toxoplasmosis with hepatic involvement the pattern of serum transaminase ac  tivity that evolved in a newborn infant with congenital toxoplasmosis and in another new  born infant with congenital cytomegalic in  clusion disease is described this enzymatic pattern was unlike that found in infants with any other cause of neonatal jaundice studied to date
MED	impaired development of rat liver enzyme activities at birth after irradiation in utero development of activity of three liver enzymes at birth was studied in rats re  ceiving 180 rads of x rays on day 15 of gestation at 20 days of gestation activities of lactic and glycerophosphate dehydrogenases and glucose 6 phosphatase were not altered the subsequent increases in enzyme activities in the 3 days between 20 days of gestation and 1 day of age were only 30 to 60 of those observed in controls this finding suggests that irradiation in utero may alter later development of enzyme activity in the perinatal period
MED	cytological and cytochemical study of hepatic cells in the human embryo changes in golgi apparatus and mitochondria as well as in the contents of nucleic acids proteins polysaccharides lipids and iron in the hepatic cells of developing human embryo were studied the data obtained in human embryos and adults were compared it was found that during the developmental process some changes in localisations of golgi apparatus and iron salts were taking place the contents of rna and polysaccharides in the cytoplasm increased mitochondria in the form of granules were revealed throughout the embryonic period and in adults no essential alterations in the contents of dna proteins and lipids were noted
MED	risk of severe jaundice in glucose 6 phosphate dehydrogenase deficiency of the newborn the incidence of g  6 p d deficiency and neonatal jaundice in all male infants born in one year in an area of the island of lesbos was studied of 634 infants tested 29 4 6 were found to be g  6 p d deficient hyperbilirubinaemia of 16 mg per 100 ml or over was observed in 34 of g  6 p d   deficient newborn males and in 9 1 of those with normal enzyme activity  in more than half of them in the absence of incompatibility or prematurity this is the first time that such a high incidence of severe neonatal jaundice has been reported in both a g  6 p d  deficient and a g  6 p d  normal group it is postulated that in the population of lesbos a second factor increases the incidence of neonatal jaundice especially when this factor is combined with g  6 p d deficiency
MED	studies of b glucuronidase acti  vity in bile and liver of devel  oping chick embryos and chicks in search for the reason of the occur  rence of unconjugated bilirubin and biliverdin in chick embryo and in chick bile the possibility of a b glucuronidase function must be taken into serious con  sideration
MED	jaundice in infancy most causes of jaundice in infancy are discussed the empha  sis has been on those syndromes solely or usually encountered in the neonate and infant
MED	absence of the cystic duct a case of congenital absence of the cystic duct is described the 18th reported case in the literature the embryogenetic basis of anomalies of the extrahepatic biliary tree is discussed methods of early operative recognition and surgical management of the anomaly are suggested
MED	familial extrahepatic biliary atresia a fifth family with familial congenital extrahepatic biliary is described clinically and pathologically familial and nonfamilial biliary atresia are similar except for a predominance of males in the familial condition the sex incidence and association of other congenital anomalies is discussed in relation to a possible etiology further in  formation must be correlated and new facts uncovered before the nature of this syn  drome will be known
MED	linfangiografia no estudo da filariase linfatica in the first part of the present paper a study is presented of the lymphangiogram of the normal african the author has noticed that it is coincident with the one of the white indi  vidual the second part includes the lymphangiographic examina  tion and the observation of lymph circulation via risa during the several stages of lymphatic filariasis even during the asymptomatic stage lymphangiography shows ganglial hypertrophy with a slight fibrosis and occa  sional discreet alterations of the lymphatic trunks in the symptomatic stage the lymphangiographic aspects vary according to the diseases different stages and there is not always a relationship between the duration period of the symptoms and the changes observed in lymphangites there are frequent alterations of the lymphatic trunks i e increase in caliber extensive and seg  mentary dilatations numerical decrease with visualization of anastomoses and higher permeability circulatory trouble evi  dences itself not only by a decrease in the rate of the lymph flow but also by a very marked ganglial retention in adenites in spite of the marked ganglial hypertrophy due to intense sclerosis there may be no considerable altera  tions in the lymphatics but risa already shows clear circula  tion troubles leading to lymphatic stasis in adenolymphoceles the obstruction at the primitive iliac level causes the lymph flow to deviate through the pre sacral anastomoses and reflux to the inguinal glands thus causing their dilatation and the formation of varicosities in the affe  rent lymphatics in lymphedemas our lymphangiographic results together with risas allow us to assume that the pathogeny is chiefly influenced by three factors lymphatic obstruction due to lym  phangitis insufficiency of the collateral ducts and ganglial sclerosis
MED	adjuvant chemotherapy in cancer of the large bowel the completeness of reporting the avail  ability of continuous statistical analysis to warn of adverse effects and the accumulation of 300 cases a year have demonstrated that this cooperative study group can provide a rela  tively quick assessment of a new approach to treatment of cancer of the large bowel it is hoped that a study begun in january 1962 on the use of 5 fluorodeoxyuridine as an adjuvant to adequate excisional surgery may demon  strate that with a drug known to produce objective remissions in 20 per cent of a group of unresectable cases of colon carcinoma the five year survival rate in curative resections may be improved
MED	cancer chemotherapy by prolonged arterial infusion our current experience is reported with 136 patients treated by prolonged arterial infusion chemotherapy the patients pre  sented a variety of far advanced cancers un  suitable for conventional surgical or roent  gen therapy antimetabolite solution either methotrexate or a fluorinated pyrimidine was injected continuously through a small plastic catheter into the unobstructed artery to provide a high regional drug concentration for days to weeks the patients have received drug infusion for up to 45 days their course has been followed for up to 37 months after treatment methotrexate with antidote therapy by systemic administration of citrovorum fac  tor was used preferentially in most patients a fluorinated pyrimidine most commonly 5 fluoro 2 deoxyuridine was preferred for hepatic artery infusion of liver metastases
MED	the montgomery tube to palliate hypopharyngeal cancer three cases of advanced incurable cancer of the hypopharynx have been presented in each instance the simple procedure of insert  ing an available prothesis served as an effective palliation for an otherwise difficult or hopeless situation
MED	adjuvant cancer chemotherapy development of a dosage schedule for adjuvant cancer chemotherapy in surgical cases an account is given of the development of a dosage schedule for adjuvant can  cer chemotherapy for surgical patients this treatment was administered for two purposes as an adjuvant to radical surgery to reduce the risk of blood borne metastases as a palliative measure for non ra  dically operated and inoperable pa  tients for these purposes 3 dosage levels were fixed a maximum tolerated dose for ad  juvant therapy a maximum tolerated dose for pa  renteral palliative therapy a maximum tolerated dose for oral palliative therapy for this treatment the authors used 2 antimitotics sp i and sp g both of which are podophyllin derivatives
MED	surgical palliation for lung cancer the results of resecting incurable lung cancer in an effort to improve the terminal course of a small number of patients are briefly presented this is not a comparative study and no in  ferences or conclusions are justified regarding the choice of this form of therapy as palliation in preference to other forms of palliative ther  apy however we do believe that the terminal course of the patient with lung cancer is bene  ficially effected by removal of the primary tumor whenever this is technically feasible
MED	management of advanced endometrial adenocarcinoma with medroxyprogesterone acetate a basis for progestin therapy for patients with advanced endometrial adenocarcinoma is presented the criteria for selection of patients for hormone therapy and the sched  ule of administration of medroxyprogester  one provera is discussed evaluation of patients for objective changes only i e by visual palpable histologic or roentgeno  logic means revealed complete or partial remission with significant palliation in 8 of 20 patients 40 per cent response to me  droxyprogesterone therapy is apparently re  lated to degree of differentiation of the pri  mary neoplasm the well differentiated le  sions being more responsive documentation of tumor effect by serial biopsies during treatment provides an index to the histologic changes this progestin produces in suscep  tible cases the effects of therapy upon serial urinary hormone excretion rates is documented in several patients on the basis of our experience the treat  ment of patients with advanced endometrial adenocarcinoma with the potent progestin medroxyprogesterone seems justified
MED	chemotherapy of breast cancer the majority of cancer patients who are referred for chemotherapy are in far advanced stages of the disease the difficulty in deliver  ing an effective dose of an oncolytic agent to the involved areas may limit the results of treatment unless the patients tumor is an un  usually responsive one the variability in re  sponse between apparently similar cases of cancer of the same cell type has become in  creasingly evident and is as puzzling as the fact that 20 per cent of patients with breast cancer will live 5 years with no treatment the decisions as to the choice between chemother  apy and hormone therapy as well as to the choice of the chemotherapeutic agent to be employed may be difficult as experience increases the usefulness of chemotherapy in the treatment of cancer is becoming increasingly apparent it also has be  come apparent that chemotherapy cannot be regarded as a curative procedure in advanced cancer even though an occasional patient ap  pears to have been cured however the value of the oncolytic agents in prolonging useful survival time ameliorating many of the dis  tressing symptoms associated with cancer and providing the physician with an extra tool for a positive program in the care of the cancer patient is now established
MED	clinical experience with palliation of metastatic adenocarcinoma with 5 fluorouracil chemotherapy chemotherapy of solid tumors is becoming a more and more helpful therapeutic tool it is probable that within a few years chemother  apy will become firmly established as an ad  junct to the primary treatment of solid tumors perhaps someday a cancerocidal chemical will be devised that can actually act as antibiotics do on bacteria for this reason it is important for all surgeons interested in the treatment of cancer to try to keep abreast of the recent ad  vances in the field of chemotherapy surgeons should also begin to use some of the technics for palliation of incurable patients so that when these drugs are added to the armamentarium of primary treatment of cancer they will be familiar with the various technics and the mode of actions of the drugs 5 fluorouracil 5 fu has had extensive clin  ical use and has produced significant palliation in breast and colon cancers with about a third of these patients receiving palliation for five to six months
MED	pelvic perfusion and carcinoma of the rectum a method of regional chemotherapy through isolation of the pelvis has been presented all of the subjects were near the terminal stage at the time of perfusion the survival time and degree of palliation have been en  couraging
MED	carcinoma of the esophagus a survey of fifty seven patients with cancer of the esophagus occurring over a twenty year period is presented the presenting complaints of the disease methods of diagnosis and char  acteristics of the disease are discussed three equal treatment groups consisting of no treat  ment x ray treatment and surgical resection were compared and the results were extremely poor only one patient in all three groups sur  vived longer than two years it was our con  clusion supported by the opinion of others that x ray therapy gave the best palliation in most cases and that surgical resection for cure should be used in only the most suitable pa  tients
MED	carcinoma of bladder cobalt therapy from 1959 to 1962 202 patients have received radiotherapy for carcinoma of the bladder radi  cal therapy with cobalt 60 has been done in 121 of these cases these patients received tumor doses in excess of 5000 rad in 3 weeks of 49 pa  tients followed for 2 years after radical treatment 28 are alive sixteen out of 32 patients with stage b2 c or d tumors are alive while 15 pa  tients survived out of 30 with tumors of grades 3 and 4 broders four of the 28 survivors had cystectomy performed and none showed residual disease in the bladder or lymph nodes the com  plications of radiotherapy presented were not considered to be excessive we believe that radiotherapy should be the initial treatment for patients with infiltrative carcinoma of the bladder the survivals pre  sented at 2 years are better than those quoted for radical cystectomy whitmore and marshall and useful bladder function is preserved for the majority of survivors we reserve cystectomy for specific indications
MED	polyposis of colon as seen in private practice familial polyposis of the colon may present itself in a variety of clinical en  tities from the cases discussed in this paper the following forms may be enu  merated 1 an asymptomatic phase with dis  crete polyposis 2 a mildly asymptomatic stage with diffuse polyposis 3 a premalignant phase with car  cinomas in situ 4 grossly malignant phase char  acterized by anemia and carcinomatosis possibly of multicentric origin to secure a complete cure it is im  perative that the clinician discover and the surgeon treat the disease in its pre  malignant state worthwhile palliative results may be obtained by surgery in incurable cases by extensive resection of the primary lesions and subsequent resection of any recurrences or metastasis whether local or distant by second and third looks is necessary special emphasis should be paid to the emotional problems of the patients an encouraging sympathetic attitude on the part of the surgeon is essential and rewarding
MED	systemic chemotherapy for cns metastases of solid tumors of the 13 cases studied remissions were ob  tained in eight this 62 remission rate is not significant because of the number of variables present however we believe that chemother  apy for this type of patient is indicated as sup  ported by the reported data the results suggest that the blood supply to solid tumors is different from that of tumors associated with hematopoi  etic disorders the latter respond very poorly if at all to systemic therapy although we were not able to measure the central nervous system cns lesions exactly the regression of the cns symptomatology was significant in pa  tients who had other demonstrable metastatic disease those lesions also regressed with this evidence we feel that patients with metastatic cns lesions even when these have recently resulted in paralysis or seizures should be con  sidered for systemic chemotherapy
MED	combined 5 fluorouracil and supervoltage radiation therapy in the palliative manage  ment of advanced gastrointestinal cancer a pilot study malcolm y colby margaret a holbrook 5 fluorouracil in combination with supervoltage radiation therapy was employed in the palliative treatment of 44 pa  tients with advanced gastrointestinal carcinoma a total dose of from 40 to 50 mg per kilogram of body weight of 5 fluorouracil given by rapid intravenous injection at the onset of radiation therapy was found to be relatively safe and tolerable larger doses were associated with excessive toxicity and mortality a sufficient number of patients achieved objective and subjective palliation to justify controlled study of the possible additive or synergistic role that 5 fluorouracil may have when combined with radiation therapy
MED	palliation by radiotherapy the purpose of radiotherapy in the management of cancer of the lung is first to cure the disease second to prolong useful and comfortable exist  ence and third to provide comfort and relief of suffering to those who are symptomatic and in  curable cancers of the lung vary quite widely in their response to radiation those of glandular origin the adenocarcinoma are more often than not of modest susceptibility and sometimes quite resis  tant the very undifferentiated the so called oat  cell cancers are often of exquisite sensitivity re  sponding to irradiation almost like lymphomas most cancer of the lung however is squamous cell carcinoma and as such may be considered to be moderately radiosensitive in much the same order of magnitude as squamous cell carcinoma of the skin cervix or larynx and should in theory be curable by this means in the same degree unfor  tunately this has to date not been found to be true the reasons are principally two first and foremost by the time a diagnosis is made cancer of the lung has more often than not estimated at 80 and more spread beyond the site of origin thus making cure by any effective means presently available unlikely second the substrate in which the cancer grows the lung tolerates radiation less well than do the tissues which surround the highly radiocurable epithelial cancers such as carcinoma of the skin cervix and larynx thus making an un  favorable therapeutic ratio
MED	chlorambucil prednisolone therapy for disseminated breast carcinoma over a 7 1 2 year period 71 patients with disseminated breast cancer were treated with combined alkylating agent cortico  steroid therapy chlorambucil and pred  nisolone were the drugs of choice these agents administered orally produced no serious or disagreeable toxic effects twen  ty four patients 33 8 had objective regression of six months duration or long  er average survival time after therapy was 23 9 months results are statistically similar to those obtained with sex steroid and endocrine ablation therapy presum  ably because the three modalities have a similar mechanism of action ie suppres  sion and or eradication of endogenous estrogen
MED	recent advances in the treatment of cancer of the esophagus whether combining surgery and supervoltage radiation therapy will noticeably improve the 5 year survival rate for carcinoma of the esopha  gus remains to be seen it is encouraging however to observe at the time of operation that the previously irradiated esophagus is firmly encased in fibrous tissue which gives the impression that the danger of disseminating tumor at the time of resection is diminished in addition the fibrosis sug  gests that the tumor that had spread locally beyond the limits of surgical excision may have been destroyed
MED	cyclophosphamide in the management of advanced bronchial carcinoma forty patients suffering from advanced bronchial carcinoma who were treated with cyclophospha  mide are reviewed the selective effect of the drug in tumours of the oat cell type is noted it is suggested that relapses which occur while the patient is on oral maintenance therapy may be controlled by a further intravenous course of cyclophosphamide full clinical and statistical details of all the patients referred to in this paper are available on application to the author
MED	esophageal obstruction the use of an endoscopically inserted tube in the care of esophageal carcinoma our experience suggests that the en  doscopic insertion of intraluminal tubes provides a relatively simple and reason  ably safe method of dealing with some of the problems which arise in the man  agement of patients with esophageal car  cinoma such tubes would appear to be of particular use in handling the prob  lems of obstruction and regurgitation in patients with incurable tumors but may also be helpful in preparing severely debilitated patients with esophageal car  cinoma to withstand the rigors of opera  tion and radiation therapy
MED	palliative radiation therapy the care of the patient with incurable cancer may be directed by physicians of various backgrounds and per  suasions if this physician has little experience in such care he is prone to be influenced by still prevalent atti  tudes of therapeutic futility or by equally unjustified premature claims for widely publicized methods recent on the scene surgery and radiation therapy remain the dominant treatment forces for the patient with cancer it is unfortunate that lack of demonstration of good radiation therapy has led to unjustified condemnation of the method rather than the user with resultant loss to the patients welfare to obtain maximal benefit radiation therapy must be allowed indications and contraindications like any therapeutic modality these must be the responsibility of the therapeutic radiologist application of realistically stringent indications and contraindications does not lessen useful accomplishment but avoids unnecessary morbidity waste of time money and effort and delay in seeking suitable treatment
MED	carcinoma of the middle ear the results of radiotherapy in a relatively large number of cases of carcinoma of the middle ear are reported the crude 5 year survival rate of 100 cases is 29 there is no difference in survival between those cases who had a preliminary mastoidectomy and those who did not the use of megavoltage x rays probably increases the survival rate
MED	sustained palliation in ovarian carcinoma management of 64 cases of advanced ovarian carcinoma has been analyzed an attempt is made to compare the value of radiation and the value of chloram  bucil using salvage time and sustained pal  liation as end points chlorambucil an outpatient oral medi  cation appears to be as efficacious as ra  diation in advanced ovarian carcinoma chlorambucil may be used before or after irradiation therapy pleural and peritoneal effusion respond favorably to chlorambucil 80 of the time the possibility of using a different dosage schedule is discussed
MED	clues in dealing with cancer patients it is clear that the patient with cancer changed his pattern of communication at different stages of the disease these patterns in communication were the basis or clues for the doctor and paramedical personnel to consider in making total care more effective the bedside clinician of past days knew these clues instinctively in his wise ministrations thanks to a gifted social worker these have been now made manifest to help all of us in dealing with cancer and perhaps other chronic relentless diseases
MED	radon and radioactive seed volume implants for extensive recurrent vaginal pelvic cancer radioactive seed volume implants for extensive recurrent vaginal pelvic cancer result in extended control of otherwise untreatable disease immediate and early reactions are practically nonexistent late complications are also rare the most serious being severe hemorrhagic cystitis in 2 of the authors 13 patients
MED	terminal cancer nursed at home perhaps the most difficult part of mrs browns illness was that she herself knew all about it she had been a nurse for most of her working life and was only too aware of the deteriorating process of carcinoma there were times of course when she would try to deceive herself say  ing that there was always hope that something new in the way of treatment would turn up and life would then be worth living again
MED	advanced cancer of the breast treated primarily with irradiation the five year results in 109 patients treated primarily with irradiation for cancer of the breast mostly in the late stages have been analyzed in all cases the initial intent was to control with x radiation alone the primary tumor involving the breast and its entire lymphatic drainage irradiation remained essentially the sole method of treatment in 84 cases postirradiation mastectomy was performed in the 25 other patients who initially had been considered inoperable the plan of treatment has consisted of a single continuous course of radiation ther  apy protracted over a period of seventy  five to one hundred days and administered in 3 closely integrated phases tissue doses superficial and deep must be brought to the highest levels required for maximum biological effects within the tolerance of the structures involved the immediate effects of irradiation alone have been remarkable the re  gression of neoplastic manifestations in the breast and palpable nodes the degree of healing of ulcerated carcinoma and the incidence of recurrence have been re  corded and assessed to determine the efficacy of treatment
MED	the management of disseminated cancer of the breast when mammary cancer has spread to tissues beyond the breast and axilla the disease is incurable by present day methods however the patient may be greatly helped and tumor growth retarded by skillful and sympathetic application of irradiation surgical ablation hormone ad  ministration and chemotherapy given in conjunction with analgesics sedatives and ataractic drugs these measures can frequently reduce disability and pain and prolong the period of useful comfortable life
MED	toilet training of an autistic eight year old through conditioning therapy a case report operant conditioning techniques have been successfully used in the treatment of a wide variety of be  havioral problems including hysterical blindness brady and lind 1961 tics barrett 1962 psychotic symptoms lindsley 1956 1960 1961 reading disabilities rachman 1962 stuttering flanagan et al 1958 enuresis mowrer and mowrer 1938 lovibond 1961 1963a b and encopresis neale 1963 madsen 1965 neale 1963 successfully treated three out of four encopretic children using operant training techniques in the case of one 9 yr old boy with an 18 month history of encopresis going to the toilet was rewarded by a candy praise and recording the event in a special book in the boys presence soiling was not inadvertently rewarded e g attention or punished the boy would be given a clean pair of pants without comment neale reports that response to treatment was rapid and complete and 6 months after toilet training there had been no relapse in bowel habits procedures similar to those used by neale were used in the case reported here positive and in a small number of instances negative reinforcement were used to toilet train an 8 yr old boy diagnosed by a child psychiatrist neurologist as having infantile autism
MED	incidence of symptoms of early infantile autism in subsequently hospitalized psychiatric patients this study was concerned with the relationship between the occurrence dur  ing the first two years of life of symptoms of early infantile autism as retrospective  ly reported by the mothers of ss and subsequent adjustment the mothers of 69 unmarried young hospitalized psychia  tric patients were interviewed to deter  mine the presence or absence of each of 28 different signs contained in a check list the signs represent characteristic features that are reportedly often found in conjunction with early infantile autism as a control 50 mothers of high school students residing in the community and presenting no significant adjustment prob  lems were questioned in regard to the very same items the results indicated that there were significantly more symptoms reported for patients than for normals and that this finding applied to the overall number of symptoms as well as to several subcate  gories of symptoms the items classified under the heading of social withdrawal appeared to be the most sensitive in dif  ferentiating the groups it was also found that 11 of the 28 signs distinguished be  tween the patients and normals with all except one occurring more frequently in the former group it was concluded that a significant relationship existed between the reported presence of symptoms that are often associated with severe and early ego impairment and subsequent status as a mental hospital patient this study does not provide any direct answer to the ques  tion of what proportion of children with infantile autism are later able to make an adequate adjustment outside of a mental hospital
MED	eeg abnormalities in early childhood schizophrenia a double blind study of psychiatrically distrubed and normal children during promazine sedation eeg tracings during promazine sedation were obtained on 58 children who had autistic or symbiotic childhood psychosis for comparison eegs were done under identical conditions on 4 other groups of children 44 with chronic undifferentiated schizophrenia 37 non psychotic children with severe acting out behavior disorders 10 with neuroses and 13 psychiatrically normal children final clinical diagnoses were made without knowledge of the eeg readings as determined for this study and the eegs were all placed in random order and read without any knowledge of the clinical diagnosis eeg abnormalities ac  cepted were focal slowing focal spikes paroxysmal spikes and waves and par  oxysmal spikes and waves with independent spikes among the 149 patients 51 had abnormal records none of the psychiatrically normal children had eeg abnormalities except for the neurotics the eeg abnormalities were qualitatively and quantitatively sim  ilar in the psychiatric patients the most frequent abnormalities were ir  regular paroxysmal spike and wave com  plexes often best seen during the transition from wake to sleep of the 149 patients 33 had this complex either alone or with independent spikes although these complexes were most frequent in the au  tistic symbiotic group the incidence was not statistically significantly different from the higher performing chronic undiffer  entiated schizophrenics who had communi  cative speech or the non psychotic children with acting out behavior disorders of the 58 autistic symbiotic children 19 had seizures which is similar to the 13 seizure incidence in the remaining 91 psy  chiatric patients whether the cerebral dysfunction im  plied by this study is a primary disorder or is secondary to some factor such as the effect of prolonged anxiety on body chem  istry cannot be decided at this time never  theless an organic concomitant has been demonstrated in 51 of the psychiatrically disturbed children by increasing the amount of time included in the eeg sam  ple the incidence of electrical abnormalities might be even higher
MED	on early infantile psychosis the symbiotic and autistic syndromes in conclusion i wish to state that the core of child psychosis must be sought in one or the other of the described distortions of the sym  biotic phase in the first case what lay at the heart of the psychotic dis  turbance was the marked emotional unavailability of the mother which alternated with a purely physical extreme closeness during the breast feeding situations and particularly with the destructiveness of the mothers unpredictable rage attacks the contrasting experiences drove the child to the autistic warding off of any human contact and the de animation of the world of reality constitutional factors could not in this case be evaluated with any degree of accuracy in the second case it was by contrast the mothers ever presence that created an unendurable instrusion upon and interference with the structuralization of the budding ego which constitutionally and perhaps predispositionally may have been very vulnerable this made it impossible for the infant to experience the normal alternation of the gratification frustration sequences at his own pace it also made the process of individuation in the separation individuation period one which was beset with abysmal panic in both instances we can see that it was primarily in the severe dis  tortions of the normal symbiosis that the child psychosis had its roots
MED	autopathy follow up of cases the publication of two papers recently in the acta paedopsychiatrica by d arn van krevelen on the subject of autistic psychopathy has stimulated the author to present 5 cases which appear to conform to his description the only value of this brief contribution lies in the fact that they have all been followed up for at least 10 years and this may give some idea of the eventual results in this type of cases
MED	sensory dominance in autistic imbecile children and controls in a previous experiment hermelin and oconnor 1964 it was found that autistic and control imbecile children responded most frequently to a light stimulus in conditions of bimodal simultaneous stimulation however the role of the relative intensity level of the stimuli remained to be determined in the present experiment a light and a sound or a light and a verbal command were presented simultaneously in various intensity combina  tions all responses irrespective of the stim  ulus to which they were made were rewarded autistic mongol and nonmongol imbecile children were tested in addition to a tendency for visual dominance results showed that independent of modality high intensities affected all groups nonmongol imbecile children also responded significantly more frequently to the verbal than to the sound stimulus while the other two groups did not
MED	dreaming sleep in autistic twins each of 5 year old identical autistic twins was observed during one spontaneous all night sleep session during which their electroencephalogram eye movement heart rate and chin muscle potential were recorded these autistic twins showed a similar patterning and amount of dreaming sleep to each other and to that reported for normal children of the same age
MED	twins discordant for early infantile autism a pair of heterozygous twins discordant for early infantile autism is reported and the relevant literature reviewed although mani  fest organic factors were ruled out the twins physical development was different a spe  cific emotional etiology was not demon  strated the few available twin studies offer findings consistent with the hypothesis that genetic factors are relevant to the develop  ment of childhood autism evidence is also presented that impaired acquisition of lan  guage may have hereditary determinants a second set of probably homozygous twins are reported who were also discordant for autism this second case suggests that although genetic factors may play a part in some cases the syndrome of infantile autism appears to be a reversible one in view of this set of twins and of kanners sibling data the role of genetic factors remains obscure and more twin studies properly documented with blood typing are needed
MED	evaluation and treatment planning for autistic children infantile autism is considered to be a re  action on the part of an immature organism at a primitive and undifferentiated stage of ego development little choice of defensive reactions is available the possibility of sub  limation does not exist and even though other object relationships are gradually developing the mother is still the childs primary object at this vulnerable develop  mental stage a wide range of pathological circumstances ranging from the most severe family psychopathology to the most adventi  tious physiological traumata or the most un  fortunately malignant circumstances may constitute an acute or cumulative cata  strophic stress the primitive organism tends to respond to this overwhelming stress with a paranoid reaction which is directed at the mother regardless of the actual etiologi  cal variables because the mother is still the childs primary object we believe that the child then responds with an autistic reaction and shows varying degrees of simple with  drawal obsessional behavior magical or de  lusional thought processes and consequent disruption of developmental skills speech and relationships with others many families can and do make every effort to counter the paranoid reaction of the child and do not respond to his rejection with counterrejection and counterwithdrawal some of the childs autistic symptoms may abate without formal treatment yet since the mother and family are the primary objects of the childs paranoid attitude it is felt that formal therapeutic intervention is necessary to modify the paranoid core of the autistic reaction
MED	a twenty five year view of therapeutic results thus this group of ten patients shows a complete range of chronic schizophrenia from a bright pseudoneurotic never hospitalized to an inaccessible patient chronically hospitalized for 20 years physiological therapy in the form of metrazol induced convulsions given in the course of a puberty schizophrenic psychosis has been helpful to some by making them more accessible for the total treat  ment program in the hospital or by raising their margin of tolerance sufficiently so that they could live at home and attend public schools at least for a time and at best indefinitely several of the most regressed deteriorated patients in state hospitals for many years have been brought back to some level of meaningful living again by the current drug therapy program and are still im  proving now we have not determined who the sinner may be there are many who will believe that the mother is always the sinner is she not schizophrenogenic there are others who will believe that the individual himself is the sinner since after all is he not the one whose behavior and fantasies are schizophrenic however there will be many of you attending this fifty second annual meeting of the american psychopathological association who will judge the speaker to be the sinner for have i not given you this wealth of clinical ma  terial without charts graphs or statistical evaluation
MED	group psychotherapy with preschool psychotic children and collateral group therapy of their parents a preliminary report of the first two years a group approach in the treatment of preschool aged psychotic children is reported autism is a defense against loss of the symbiotic partner the group of children penetrates this defense and forms a group ego which constitutes one pole of a new therapeutic symbiosis from which separation individuation can occur
MED	autistic reactions in early childhood differential diagnostic considerations the term autism is frequently used today in the differential diagnosis of the severe emotional disturbances of early childhood however to label a child as autistic presents some formidable problems with regard to definition of the term the specific etiological diagnostic implications and treatment considerations for any given child so designated the purpose of this paper is to briefly review some of the historical psychiatric background of the term autism its more recent ramifications and our clinical experiences in this field
MED	infantile autism a family approach the autistic child appears to be unable to integrate or to respond to stimuli both from an internal source the body as well as from external sources such as human contact we have noted in the children at our residential treatment center how in their preliminary period with us they appear to be unaware of their body they give the impression of being insensitive to pain display little autoerotic behavior inflict injury on themselves such as hitting their heads against objects and biting their own bodies with little outward display of distress in working with these children in therapy one of the guideposts for change and for growth is a display on the childs part of an increased body awareness and autoerotic behavior for example one child who developed polio during his early stay at the clinic residence did not communicate this to anyone and it was only made known by observing the childs dragging one leg memorial guid  ance clinic 1959 later he was able to point to his body and to indicate pain another child who at first seemed to be quite unaware of both himself and others concurrent with his growing display of affective expression toward the therapist also manifested pleasure through genital stimulation was quite ticklish and when injured would display the area of pain quite readily
MED	an analysis of the language of fourteen schizophrenic children fourteen schizophrenic autistic children were studied by means of detailed behavioural histories and observations the language recorded in history and observation protocols was analysed and compared with available data on normal children all schizophrenic children were grossly retarded in their language development and all measures of this correlated highly with a previous overall clinical assessment of the severity of illness the most striking abnormalities in the language of the children studied were stereotyped repetition of utterances appropriate to an earlier developmental level or to a previous environmental context accompanied by a lack of normal expressions of curiosity and of responsiveness to changing environmental cues
MED	a behavioural and electroencephalographic study of autistic children short biographies are given of 10 children age 3 to 6 years diagnosed as suffering from kanners syndrome early infantile autism an analysis was made of the free field acti  vities of these children compared with a group of normal children of similar age electro  encephalographic studies were also carried out on all 10 children and in two it was possible to carry out simultaneous behavioural and eeg observations by means of telemetry the children were observed for three minute periods in four environments of varying complexity a an empty room b the same room with toy wooden blocks present c blocks plus passive adult d blocks plus active adult except in a the visual fixations and manipulatory activities were of significantly shorter duration in the autistic children than in the normals lacked clear cut off points and showed relatively little variability between environments the autistic children as a whole showed virtually no constructive play in contrast with the normals though more time was spent in contact with play materials in the social environments changes in the time spent in locomotion gesturing block play and manipulation of other objects in the environment showed that the autistic children were acutely responsive to changes in their environment including the presence of the social stimulus if the autistic children were subdivided into those who characteristically showed stereotypies and those who did not the latter sub group showed a behaviour structure which was very similar to that of the normals whereas the stereotypy sub group was clearly differentiated from both the normal children and the non stereotypy sub group eight autistic children had waking eeg records characterized by low voltage irregular activity without any established rhythms one child a record containing irregular alpha and another unstable theta activity two of the children with flat laboratory eegs showed more rhythmic higher voltage records when their eegs were telemetred in environment a they also showed less stereotyped behaviour in environments b and d they showed pro  gressively more irregular eeg activity and more stereotypy the hypothesis is advanced that autistic children are in a chronically high state of physio  logical arousal the findings of the present study and those of other workers are discussed with respect to this hypothesis
MED	the autistic child in the school and the school nurse teacher responsibility autistic children demonstrate a more persistent pattern of retreating from reality than is apparent in those children categorized as normal some psychologists have established the cause of symptoms in the autistic child as extreme anxiety which forces withdrawal from social contact such anxiety is reported to have its initial occurrance during the age range of one to five years a sense of security which is considered es  sential for a child is gained through overt manifestations of love care and approval of those adults most closely associated with him when this need is not satisfied the childs attempts at self realization and esteem are deterred or thwarted and a state of anxiety may result the severity of the anxiety may be the forerunner of a schizophrenic disorder such a condition can develop in a child an adolescent or an adult schizo  phrenia a serious mental illness is considered to be a major cause for admitting patients to mental institutions another school of thought has placed infantile autism in the category of a disturbance resulting from abnormalities of development during the intrauterine period such a congenital condition is not categorized as mental retardation yet another concept of autism conceives of the problem as the absence of an innate ability or capacity for developing meaningful contacts with other people a detachment of varying degrees persists where human contacts are concerned
MED	the autistic child the conditions most frequently mistaken for autism are speech disorder brain damage and mental deficiency each a prominent symptom of the psychotic child careful his  tory and close observation to disclose symp  toms of withdrawal lack of ego compulsion for sameness and displays of intelligence give incomplete clues to the diagnosis the etiology of autism is uncertain sev  eral factors seem significant the important role of organic damage of the brain is under  scored by the coincidence of epilepsy eeg and neurological abnormalities in these chil  dren in our series seizures of various types occurred in 25 eeg abnormalities in 58 and minor neurological deficits in 70 of the cases environmental factors are quite obviously important in many instances the emotional and behavioral pattern of the par  ents toward the infant is often incriminated separation inattention coldness rejection etc have been found in many situations fa  milial incidence of psychoses is low so is that of autism in siblings
MED	shadow therapy shadow therapy was developed at sunland training center in gainesville florida because of communica  tion difficulties with disturbed psychotic children it was con  jectured that subjects would reveal their anxieties and conflicts more readily in a simulated night situation the therapy was conducted in a darkroom with projector light used to produce silhouettes and their accompanying shadows as additional stimuli twelve subjects attended in this article the reaction of a child who was autistic and severely disturbed is used as an illustration of subject reactions in the playroom he exhibited static behavior in the darkroom re  gressive transcendential behavior he also transcended his usual level of vocalizing and socializing
MED	language training in the treatment of the autistic child functioning on a retarded level a preliminary study to determine the effect of language and speech therapy on the development of communication and the lessening of un  relatedness in a group of non verbal autistic children functioning on a retarded level is reported on the basis of the re  sults of the study it is suggested that the inclusion of language and speech therapy techniques be considered in developing a treatment program for such children
MED	the convergence and interaction of visual auditory and tactile responses in human nonspecific cortex the relation between the electrical responses in the human brain and mental processes of integration and association is perhaps the most chal  lenging of all the problems facing neurophysiologists today until quite recently the prospect of unifying physiological and psychological concepts by electro encephalographic eeg techniques seemed to be receding because of the baffling complexity of the intrinsic electrical rhythms and this difficulty has still not been overcome the most intriguing and at the same time most elusive of the properties of these rhythms is that although often remarkably constant in their variations with respect to time they fluctuate also in a much less regular manner within the three dimensional space of the brain the continuous analysis and display of such a phenomenon presents serious difficulties and no method has yet given entirely satisfactory results the incentive to construct adequate equipment and to design and per  form crucial experiments is undoubtedly limited by the uncertainty as to whether the information likely to be obtained in this way is essential to understanding brain mechanisms few experimenters imagine that it would be sufficient
MED	infantile autism and the schizophrenias in a paper published in 1943 entitled au  tistic disturbances of affective con  tact i reported from the childrens psychi  atric service of the johns hopkins hospital observations of 11 children 8 boys and 3 girls who had in common a pattern of be  havior not previously considered in its striking uniqueness the symptoms were viewed as a combination of extreme alone  ness from the beginning of life and an anx  iously obsessive desire for the preservation of sameness i concluded the discussion by saying we must assume that these chil  dren have come into the world with an innate inability to form the usual biologi  cally provided affective contact with people just as other children come into the world with innate physical and intellectual handi  caps if this assumption is correct a further study of our children may help to furnish concrete criteria regarding the still diffuse notions about the constitutional components of emotional reactivity for here we seem to have pure culture examples of inborn au  tistic disturbances of affective contact in my search for an appropriate designa  tion i decided in 1944 after much groping on the term early infantile autism thus accentuating the time of the first manifesta  tions and the childrens limited accessibility
MED	autistic children autism is a form of childhood schizophrenia a sudden separation from his mother or traumatic shock in early life causes the child to reject the world of nor  mal relationships leading him back to the original traumatic situation is part of the treatment described in this article
MED	gilles de la tourette syndrome in an autistic child a case of gilles de la tourette syndrome presenting an early infantile autism is described the treatment applied is outlined
MED	psychodrama for disturbed children psychodrama is especially adaptable to the treat  ment of mentally ill children it evokes a degree of spontaneity and involvement that is difficult to attain with many group therapies and it offers situa  tions in which the children can participate as actors or as observers competition and restriction are minimal the child can do what comes naturally in  deed much of childrens natural play is in the form of dramatic activity their make believe is how  ever more intense than acting for a child becomes the person or thing he pretends to be a fireman an indian a horse a tiger
MED	the speech and language abilities of emotionally disturbed children the speech and language disorders of these severely disturbed children can be divided into two categories which relate to the type of psychiatric disturbance the autistic schizophrenic children used bizarre forms of language or did not use communicative language at all the non  autistic schizophrenic the neurotic the primary behaviour disorder and the minimally brain damaged children as a group had similar speech and language problems to normal children but of a more severe and frequent nature their problems were predominantly in the areas of speech and language develop  ment articulation rate of speech and fluency the children with primary be  haviour disorders had the more severe speech and language problems
MED	a study of childhood schizophrenia and early infantile autism part i  description of the sample following a period of observation of three months duration a group of twelve autistic schizophrenic children were se  lected for a treatment program the group was selected on criteria which would allow a reasonable chance of suc  cessful treatment in a group homo  geneous enough to allow statistical con  siderations to be valid younger age average intellectual func  tioning presence of an intact family in or near to metropolitan toronto and a firm diagnosis of autistic schizophrenia were the limiting factors rather distinct differences were noted in this treatment group as opposed to the larger observation group the dis  tinguishing characteristic was undoubted  ly the speech abnormalities present
MED	discussion sur les pseudo tumeurs osseuses des hemophiles doctors queneau and josso each described one case of pseudo tumour of the calcaneum analagous to that described by trillat and favre gilly they demonstrated x rays dr alagille referred to a haemophilic cyst of the maxilla and dr favre gilly to a cyst of the perineum dr kugler had seen a case where an erroneous diagnosis of osteosarcoma had been made
MED	the effect of joint position on the pressure of intra articular effusion it is known that joints with symptomatic effusions are held spontaneously in characteristic positions and that movement of these joints increases pain in the study reported here a correlation was made between the hydrostatic pressure of a joint effusion and the joints position the results indicate a possible relationship between intra articular pressure and pain
MED	haemophilic blood cyst a mongol boy of ten a known haemophiliac was seen in the orthopaedic department of southmead hospital in may 1962 with a swelling of the left foot the parents were aware of a steady increase in size since the swelling was first noticed two months before on examination a cystic swelling was seen to occupy the forefoot the skin on the dorsum being stretched over it and a dusky red in colour fig 1 radiographs showed destruction of the proximal two thirds of the third metatarsal bone an appearance consistent it was thought with destruction from within by an expanding lesion fig 2 the diagnosis of a haemophilic blood cyst was made
MED	treatment and prevention of chronic haemorrhagic arthropathy and contractures in haemophilia orthopaedic treatment of joint deformities in thirteen patients with haemophilia is reviewed over a period of seven years forms of treatment discussed include open operation manipulation under general anaesthesia continuous traction splintage and physiotherapy the amount of intravenous therapy required for each form of treatment is indicated in discussing prevention of joint deformity the histories of a further eighteen patients have been taken into account it is concluded that initially painless haemarthroses provide the main threat to joint deformity in haemophilia the best preventive treatment is early immobilisation followed by prolonged splintage and physiotherapy intravenous therapy with antihaemophilic factor plays a less important role here than in other forms of haemorrhage evidence is presented that joint deformity in severe haemophilia can often be entirely avoided
MED	osteopatia in emofilia the aa present the case material of the literature and one personal remark of extrarticular osteopathy in hemophilia they examine the anatomic and clinical picture of the illness in its most important and less known peculiarities and they dwell upon the curative medico surgical problems of the affection
MED	la plasmatherapie a minima dans le traitement de la douleur des hemarthroses hemophiliques some fifty clinically similar cases of hemophilic hemarthrosis were after immobilization either treated with placebo and plasma perfusion or else with corticoids and analgesics a very small quantity of plasma is sufficient to stop the pain for the following few hours it is attempted to give a physio pathologic explanation which would seem in accord with the pathogenic studies on hemophiliac by r marx et al
MED	effet analgesique immediat des injections de plasma pour hemarthroses recentes du genou des hemophiles a single injection of 20 ml of lyophilized fresh plasma per kg body weight is proposed as a treatment in recent cases of knee hemarthrosis with an important distension of the capsule so as to achieve hemostasis and reduce the evolutive period pain is always acute and permanent in such cases of hemarthrosis it subsides during the plasma injection or immediately afterwards
MED	hip disarticulation in a patient with hemophilia disarticulation of the hip in a hemophiliac patient was performed because of a severe osteomyelitis involving the entire right femur and was lifesaving the following are suggestions for hemotologic man  agement 1 infected wounds in hemophiliac pa  tients should be left open initially 2 electro  cautery should not be used in an infected wound of a hemophiliac patient 3 a safe fibrinogen prepa  ration potent in the antihemophilic factor is now available in this country and is a highly significant advance in the surgical treatment of hemophilia
MED	haemophilia in sweden vii incidence treatment and prophylaxis of arthropathy and other musculo skeletal manifestations of haemophilia a and b the clinical material consisted of 242 of the 308 known haemophiliacs a and b in sweden the investigation included clinical examination of all major joints in 95 of 116 patients with severe haemophilia in 38 of 65 patients with moderate haemophilia and in 24 of 127 patients with mild haemophilia and roentgen examination of practically all joints found to be abnormal at the clinical examination in addition information about 7 patients with severe haemophilia 21 with moderate haemophilia and 57 with mild haemophilia was obtained by questionnaire only the degree of arthropathy grades 2 3 and 4 was classified largely according to depalma and cotler 1956 evaluation of general disability was made with regard to ability to manage walk dress eat toilet with  out help this latter evaluation comprised also extra articular manifesta  tions of haemophilia
MED	interet de la radiotherapie dans les hemarthroses recidivantes du genou chez lhemophile radiotherapy was delivered at a dose of 100 r repeated from 7 to 10 times to 22 knees of haemo  philiac children presenting recurring arthropathies irradiation had no harmful effect on growth of patients it was beneficial in two thirds of the cases reducing considerably the number per annum of haemarthrosis onsets one third of the patients showed no significant result the number of onsets was the same in the following year totally the average of infirmary stays due to knee haemarthrosis was 175 days in the year before radio  therapy and 25 days in the following year the authors think that these results justify this therapeutic method
MED	discussion sur les donnees radiologiques dans les arthropathies des genoux professor marchal acts as moderator dr le coeur wonders if the fringed appearance of condyles has really a pathological significance that appearance could be normal in young children but in the opinion of dr queneau it seems to be patho  logical in older children it seems to dr favre gilly and dr queneau that scalariform traits occur more frequently in haemo  philiac children than in normal ones dr le coeur thought that fibrillary decalcification was the ultimate stage of decalcification whereas dr favre gilly has the impression that it represents in haemophiliac subjects an early stage anterior to homogeneous decalcification according to brinkhous densification of synovial membranes are a result of an infiltration of the joint cartilage due to haemosideraemia this is also the opinion of dr favre gilly and dr izarn dr izarn asks if geodes are caused by intra  osseous haemorrhages or necroses dr queneau and dr de mourgues think that anatomical data con  cerning haemophiliac subjects are insufficient for that question to be answered
MED	etude radiographique des genoux de 100 hemophiles de 7 a 15 ans radiographic examination of the knee were syste  matically performed in 100 haemophiliac subjects aged from 7 to 15 years 64 of whom had a bilateral haemarthrosis 30 had only one knee affected and 6 were uninjured an intra articular opacification observed in 29 knees corresponded to a recent haemarthrosis densification of the synovial membrane was ob  served in 25 knees and corresponded to iron deposits an interlinear pinch was present in 52 knees erosions of articular surfaces are especially fre  quent 78 knees or homogeneous 28 knees hypertrophy of condyles or knee caps broadening of intercondylian space crushing of internal tibial disk genu valgum and posterior subluxation of tibia are osseous deformations that are encountered atrophy of femur diaphysis explains the frequency of fracture of femur some of these aspects seem to occur early inter  linear pinch erosion of the surfaces others are tardier geodes decalcification a relation between the intensity of abnormal radio  logical findings and the severity of sequelae does not always exist but one can observe major radio  logical alterations only when there is a major bio  logical disturbance
MED	blood vascular disorders in connection with the nose throat and ear these disorders include 1 those having lesions primarily in the nose throat or ear and 2 those producing symptoms and signs in nose throat and or ear only as a part of their symptomatology and involve other organs as well we will con  sider the lesions in connection with the nose throat and ear separately
MED	volkmanns ischaemia volkmanns ischaemia is the name given to a sequence of events originally described by volkmann in 1881 basically the condition consists of the replacement of the limb flexor muscles by fibrous tissue following injury or occlusion of the main arterial supply of blood to these muscles the condition is rare fortunately  mainly because of improved methods of prevention the flexor muscles of the toes are sometimes affected but the commonest group of muscles so damaged are the flexor muscles of the forearm total arterial occlusion to a limb for several hours usually causes frank gangrene partial or total occlusion for shorter periods may give rise to ischaemic contracture the muscles being deprived of their blood supply die and are sub  sequently replaced by fibrous tissue like all scars the fibrous tissue contracts producing the complete picture of volkmanns ischaemic contracture the forearm is thin and wasted and the fingers are held in flexion owing to the overall shortening of the flexor muscles in severe cases if the nerves are also affected or if the entire muscle mass is replaced by fibrosis the fingers may be totally paralysed as well
MED	klinik der polyarthrosen among the degenerative affections of joints the symptoms of the arthrosis of the joints of the fingers with heberden nodes the bouchard nodes of the inter  digital joints the polyarthrosis   on those subjects coste and forestier wrote about and how they were described by lffb too   and the arthropathies of chronic gout are more thoroughly discussed the rare conditions as the arthrotic changes in hemo  philia psoriasis and metabolic disorders are mentioned a wider area is dedicated to the differentiation between degenerative and inflammatory diseases it is refer  red to that gout more often occurs in our days and one is forced to calculate with it more than some years ago it is also referred to the significance of the serolo  gical reactions for the differential diagnosis the most important diseases are enumerated which do not belong to degenerative polyarticular affections of joints but which very often get mixed up with them
MED	major surgical procedures including amputation on a hemophiliac various surgical procedures in a hemo  philia a patient including amputation above the knee are reported human cohn fraction i fibrinogen ahg was used to ensure normal hemostasis the patients ability to form a firm clot within a normal time was measured and treatment was prescribed in accordance with serial studies with the thrombelastograph
MED	the prevention of crippling in haemophilic children children who are severely affected with haemo  philia or christmas disease suffer repeated haemorrhages into joints and muscles after trivial injuries these episodes of bleeding produce cumulative crippling the haemarthroses tend to be recurrent each episode produces some damage to the joint surface and the immobility during con  valescence leads to muscle weakness thus after recovery the joint becomes increasingly liable to renewed bleeding the deep muscle haematomata can produce crippling by actual destruction of muscle tissue by pressure on important nerves or arteries by contractures which develop during healing and by failure of resolution of the original haematoma leading to chronic cyst formation
MED	throat and nose surgery in patients with constitutional haemostatic defects successful surgery in patients with defective haemostasis is becoming possible and it is of inter  est to detail the problems encountered in nose and throat surgery
MED	hemophilic arthropathy jaromir priborsky zora antalovska the authors report their experience with joint diseases in 54 patients suffering from hemo  philia 49 of them being cases of hemophilia a 5 of hemophilia b 21 patients were children up to the age of 14 years bleeding into the joints occurred in 66 6 of patients in the age group over 14 years the cases of bleeding into the joints were more frequent 78 8 than in the age group up to 14 years 47 7 there were no differences as to bleeding into the joints and the seriousness of articular changes between the cases of hemophilia a and hemo  philia b in most cases the bleeding into the joints began between the 6th and the 14th year of age bleeding into the joints as the first manifestation of a hemophilic condition occurred only in 9 3 of patients in most cases other hemophilic manifestations preceded in spite of this fact the joint manifestations were often wrongly diagnosed as tuberculous arthritis rheumatic fever progressive arthritis and were treated accordingly most usually the large joints knee elbow ankle were affected with bleeding and in them the changes were also the most serious the joints of both halves of the body were affected uniformly in most cases several joints were affected while monoarticular localization was observed in 16 6 the seriousness of articular changes was dependent mainly on the number of repeated bleedings into one and the same joint although other factors weight bearing of the joint complexity of the joint treatment may be of decisive importance in the individual cases as well according to clinical especially from the functional point of view and x ray criteria the articular findings were classified into three groups in the first group the function of the joint is preserved in the second limited and in the third practically extinguished the following laboratory tests were carried out erythrocyte sedimentation reaction latex test for the rheu  matoid factor c reactive protein mecoprotein tyrosine and weltmanns coagulation test the findings were normal even in cases of irreparable articular changes unless acute bleeding into the joint or in some other localization or some other complicating disorder was present simultaneously the therapy of hemophilic arthropathy remains troublesome owing especially to a frequent occurrence of articular bleeding a close cooperation of the hematologist and the rheumatologist or the orthopedist may con  tribute to the improvement of the fate of these patients
MED	prevention and treatment of joint deformity in haemophilia experience in treating established joint deformities in 27 patients and preventing the development of deformtiy in 10 younger patients during the last 8 years has shown that there are two types of haemorrhage which require different treatment to prevent chronic deformity
MED	the haemophilic pseudotumour or haemophilic subperiosteal haematoma the case history of a haemophiliac in whom a large haematoma of the thigh was treated by amputation of the limb is described examination of the available radiographs and of the histology led to the conclusion that the cyst was subperiosteal in origin evidence is presented to support the hypothesis that haemophilic pseudotumours are always associated with subperiosteal haemorrhage and that those haemophilic cysts which are confined to muscle have little or no effect on the adjacent bone
MED	actinomycin d and the response to parathyroid hormone actinomycin d inhibits the effect of parathyroid hormone upon bone as measured by ca mobilization without altering its effects upon the renal excretion of phosphate and ca in rats
MED	aspects of circadian periodic changes in phosphorus metabolism in mice kinetic studies on the p32 content of mouse brain phosphorus fractions following the intraperitoneal injection of p32 labeled orthophosphate were performed during two selected segments of the 24 hour time scale the results of these studies suggest that the circadian periodicity in relative specific activity of brain phospholipids is probably a consequence of a variation in the extent of p32 incorporation into brain inorganic phosphate and is not indicative of a periodicity in the rate of intermediary phospholipid metabolism data on the postinjection time course of the specific activities of plasma inorganic phosphate liver inorganic phosphate and liver phospholipid suggest a similar explanation for the circadian periodic changes in relative specific activity of liver phospholipids a circadian rhythm of inorganic phosphate concentration in mouse plasma is demonstrated consideration of a mathematical model suggests that the observed within day variation in p32 distribution and the circadian periodicity of phospholipid relative specific activity in liver and brain are a consequence of this periodicity in plasma phosphate content a significant within day variation in total phosphorus content of liver was observed the disturbance of mice incident to p32 injection has a marked effect on the plasma content of inorganic phosphate and corticosterone
MED	specificity of the inhibition of tubular phosphate reabsorption by certain amino acids the inhibition of tubular phosphate reabsorption by certain amino acids is a highly specific one in which differentiation between such closely related compunds as the d and l isomer is clearly possible
MED	localization of phosphaturic effect of parathyroid hormone in nephron of the dog the renal mechanism and tubular site of the phosphaturic action of parathyroid hormone were investigated by clearance and stop flow techniques in one intact and seven thyroparathyroidectomized dogs administration of hormone caused a significant increase in the excretion of phosphate without increasing the filtered load stop flow analysis indicated that in the absence of parathyroid hormone most of the filtered phosphate was reabsorbed in the proximal tubule and that the hormone increased the rate of phosphate excretion by inhibiting this reabsorptive mechanism p32 injected during stopped flow showed no significant transport across the renal tubule despite the presence of excess parathyroid hormone significant p32 activity appeared in the stop flow collections simultaneously with the appearance of new filtrate there was no evidence that parathyroid hormone mediated a secretory process for phosphate excretion
MED	the regulation of growth hormone secretion in the present communication we summarize our investigations on the control of secretion of hgh using radioimmunoassay for the measurement of plasma gh the assumption implied throughout this presentation that changes in secretory rate are responsible for acute changes in plasma concentration of hgh appears reasonable since the fluctuations in plasma hgh concentration are often too rapid to be caused solely by alterations in hormonal degradation or excretion for slower changes in plasma hgh concentration however alterations in the rate of removal of hormone from the body fluids might play a contributory role however there is no evidence that important changes occur in the rate of removal of hgh from the circulation except in patients who have developed antibodies to hgh following treatment with hgh
MED	early infantile autism and receptor processes the syndrome of early infantile autism is examined as a function of deviation in near distance receptor usage these receptor deviations are compared with normal receptor hierarchies developing from near to distance receptor dominance the available information is consistent with the view that early infantile autism involves early sensory deprivation this sensory deprivation results from an interaction between a constitutional deficiency inhibiting certain reticular arousal functions and mothering tending to understimulation treatment of the young autistic child is suggested including stimulation and communication via the available near receptor systems in the framework of sensory development directions for the study of early diagnosis and treatment are indicated
MED	studies on compensatory renal hypertrophy i effect of unilateral ureteral ligation and transection data are presented comparing the relative rate of compensatory renal hypertrophy and hyperplasia of the control kidney of rats following either unilateral ureteral transection ligation or nephrectomy the growth of the control kidney on the unoperated side was strikingly slower after ureteral transection and ligation when compared with that resulting from the removal of one kidney progressive hydronephrosis was observed on the operated side following ureteral transection and ligation and was more pronounced in the latter degree of hypertrophy of the control kidney showed a close correlation with degree and duration of the hydronephrosis of the kidney on the operated side these observations have been interpreted as indicating the operation of a control system regulating kidney growth in response to changes in some way related to kidney size
MED	studies of the changes in growth and dna synthesis in the rat kidney during experimentally induced renal hypertrophy there is a high rate of accumulation of newly synthesized dna in the kidney after folic acid injection compared with the small increase during the first few days after unilateral nephrectomy there is a large increase in the water content of the kidney after folic acid which does not occur after unilateral nephrectomy the changes in the wet and dry weight and the rna and dna content of the kidney have been compared after administration of folic acid unilateral nephrectomy and unilateral nephrectomy followed by folic acid 24 hr later in an attempt to study the nature of these differences after unilateral nephrectomy there was a steady increase in wet weight dry weight and rna content of the kidney each parameter reaching about 35 to 40 above normal by 14 days by which time the dna content had increased by only about 25 an increased rate of dna synthesis was found between 2 and 4 days returning almost to normal by 7 days after folic acid injection there were very large increases in wet weight 60 rna content 100 and dna content 70 during the first 4 days accompanied by a smaller increase in dry weight 30 thereafter these parameters declined relative to body weight returning almost to normal by 14 days the rate of dna synthesis was greatly increased as early as 24 hr after injection and reached a much higher level than that found after unilateral nephrectomy before returning to the normal level by 7 days when unilateral nephrectomy was followed 24 hr later by folic acid injection the increases in weight nucleic acid content and rate of dna synthesis were greater than at the corresponding times after either treatment alone marked differences were found in the labeling indices of kidney cells after either unilateral nephrectomy or folic acid injection the latter treatment resulted in very large increases in all three zones of the kidney whereas after unilateral nephrectomy the responses of the cortex and outer medulla were much lower with no significant increase in the inner medulla when both treatments were combined the response of the remaining kidney was similar to though more exaggerated than that of the normal kidney after folic acid injection
MED	renal and adrenal relationships in compensatory hyperplasia the compensatory renal hyperplasia that normally follows unilateral nephrectomy is abolished by bilateral adrenalectomy if rats are maintained on fresh drinking water but is restored when saline drinking water is provided or if such animals are injected with doca the adrenals are also important for the increased proliferation caused by unilateral hydronephrosis these experiments suggest that the role of the adrenal cortex in renal hyperplasia may be to secrete mineralocorticoids which promote the retention of sodium and thereby stimulate cell division in the kidneys
MED	a genetic study of neonatal obstructive jaundice 58 children with extrahepatic biliary atresia 7 with intrahepatic biliary atresia and 50 with neonatal hepatitis were analysed concerning diagnostic criteria natural history familial clinical and pathological data in extrahepatic biliary atresia there is no evidence of a familial tendency influence of maternal age birth order or disturbance of foetal development in neonatal hepatitis there were 4 consanguineous parents suggesting a mutant autosomal gene in homozygous form some infants with the genotype for neonatal hepatitis may manifest a very mild or a very severe form so a diagnosis was not made an apparent excess of males over females may be another evidence of failure of manifestation of the genotype but neonatal hepatitis may be a manifestation of more than one disease in neonatal hepatitis the birth weight shows a marked decrease perhaps as a sequence of disturbed liver function in the foetus
MED	parathyroid extract induced changes in the oxidation of citrate succinate and other organic acids by liver parathyroid extract pte or partially purified parathyroid hormone administered in vivo markedly altered the oxidation in vitro by rabbit liver minces of citrate  keto glutarate c succinate c fumarate c and lactate with ca present in the incubation medium minces from pte treated animals produced more co and had a greater o consumption than did control minces this stimulation was due in part at least to a more rapid decline in metabolic activity of the control tissues when ca was absent total metabolism was increased and the tissue derived from pte treated animals was less active than the control tissue the effect was detected as early as 4 hr after injection 750 u kg and could be elicited with as little as 200 u at 14 hr the action of pte could not be duplicated by the injection of cacl into the animal the data suggest that one effect of treatment was a general inhibition of oxidation the stimulation of metabolism could be a consequence of this inhibition or a separate unrelated alteration
MED	actinomycin and erythropoiesis and the production of erythropoietin in mice in b6d2f female mice a single dose of 10 of actinomycin will suppress normal erythropoiesis fe erythrocyte uptake in polycythemic mice 2 is enough to prevent the stimulatory effect of 0 25 a units of erythropoietin the curves of suppression and recovery versus time support the hypothesis that erythropoietin acts for a short time in an early stage of erythropoiesis after this early stage developing cells are no longer so sensitive to actinomycin recovery even from repeated doses is rapid and adequate amounts of actinomycin which are adequate to abolish erythropoiesis do not prevent the new appearance of erythropoietin in the plasma of hypoxic mice
MED	the ultrastructure histopathology and histochemistry of the parathyroid glands of pregnant and nonpregnant cows fed a high level of vitamin d the parathyroid glands of pregnant and nonpregnant cows were studied by light and electron microscopy following the daily feeding of 30 million units of vit d for 30 days and compared to untreated controls in both the pregnant and nonpregnant cows the parathyroid glands became markedly atrophic with a diminution in the amount of parenchyma compared to the untreated controls after vit d feeding the number of actively secreting dark and intermediate chief cells was reduced and the percentage of inactive light and atrophic chief cells was increased the parathyroid glands of the vit d fed nonpregnant cows were dominated by severely atrophic chief cells these cells were characterized by their highly irregular shape shrunken nucleus and cytoplasm widened intercellular spaces traversed by numerous cytoplasmic processes increased electron density few secretory granules inactive ergastoplasm and golgi complexes atrophic chief cells were not present in the untreated controls the predominating cell type in the parathyroids of the vit d fed pregnant cows were the inactive chief cells in contrast to the atrophic chief cells they were larger and more regular in shape with relatively straight cell membranes they were comparatively electron transparent containing more glycogen and fewer secretory granules organelles concerned with protein synthesis and packaging into secretory units were poorly developed inactive chief cells were observed only occasionally in the parathyroid glands of untreated pregnant cows where the actively secreting dark and intermediate chief cells predominated
MED	effect of heparin and parathyroid extract an acid phosphatase in bone to test the theory that heparin might stimulate acid phosphatase in the bone of young rats heparin pte or a combination of both were injected after an appropriate time interval acid phosphatase activity of bone of treated animals was compared with controls it was found that heparin enhanced the pte stimulated acid phosphatase activity of both calvaria and metaphysis but not diaphysis the possible relation of these facts to the presence of lysosomes in osteoclasts was discussed
MED	the isolation of thyrocalcitonin and study of its effects in the rat the thyroid secretes a polypeptide hormone thyrocalcitionin which is effective in lowering plasma calcium and phosphate the hormone can be extracted from the thyroid of the rat dog pig goat ox and monkey the isolation of the hormone from pig thyroid by a combination of salt fractionation and gel filtration is described one microgram of the pure material is very active in the rat thyrocalcitonin remains effective after parathyroidectomy after nephrectomy after overdosage with vitamin d during vitamin d deficiency and during calcium or magnesium deficiency its action is not prevented by prior administration of actinomycin d a single injection does not change soft tissue calcium but infusion for 12 hr lowers cardiac muscle calcium it is concluded that this new thyroid hormone acts on bone and that it probably plays an important role in normal physiology
MED	the effect of actinomycin d on parathyroid induced change in bone and kidney actinomycin d amd an antibiotic known to inhibit dna directed rna synthesis was used to study parathyroid induced changes in ca mobilization in vivo and in vitro as well as renal excretion of ca and phosphate in rats intact and parathyroidectomized rats subjected to peritoneal lavage were administered amd and changes in ca p and mg in lavage and serum were examined amd consistently lowered the ca transfer into the peritoneal rinse in both the intact and parathyroidectomized animals although the drop in ca was more acute if the animals were pretreated by subcutaneous injections of amd than if amd was administered as a component of the rinse pretreatment of lavaged animals with amd prevented the expected increase in osteoclast numbers in the distal metaphysis of the femur but had no effect if administered as a component of the peritoneal rinse the incubation of femora removed from both intact and parathyroidectomized animals resulted in media ca levels that were significantly lower after 4 hr incubation when amd was added in vitro however transfer of recently injected ca into the incubation medium from animals treated with amd was increased in addition parathyroidectomy of animals subsequent to administration of amd still resulted in expected changes in ca and p in the urine although amd significantly increased p excretion in both intact and parathyroidectomized animals it was concluded that endogenous parathyroid hormone requires the continuous production of enzymes ultimately responsible for its action on bone and kidney but that this action is not necessarily related directly to the production of m rna
MED	inhibition by actinomycin d of bone resorption induced by parathyroid hormone or vitamin a actinomycin d inhibits cell proliferation in control cultures of embryonic rat bone and prevents the stimulation of bone resorption by parathyroid horome pth or vit a with a dose of 0 004 ml of actinomycin d pth effects are only partially inhibited and this inhibition can be overcome by increasing the dose of pth these findings suggest that these agents act competitively
MED	j clin endocr 1965 25 4 457 464 antagonism between parathyroid extract and adrenal cortical steroids in man metabolic balance studies were done in 2 patients with hypoparathyroidism who received hydrocortisone of prednisone during the administration of parathyroid extract administration of prednisone was associated with phosphate retention decreased urinary ca decreased serum ca citrate and glycoprotein concentrations and increased serum phosphate excretion of parathyroid activity in the urine of 1 patient was uninfluenced by the administration of prednisone it is concluded that the antagonistic effect of the adrenal cortical steroids was expressed at the biochemical sites of action of the parathyroid extract in bone and kidney that the steroids reduce parathyroid secretion but that their administration probably does not result in degradation or inactivation of the hormone
MED	tissue distribution of electrolytes ca and mg in experimental hyper  and hypoparathyroidism the effects of experimental hyper  and hypoparathyroidism on plasma and tissue distribution of electrolytes and tissue exchangeability with ca and mg were studied in dogs following acute renal pedicle ligation in hyperparathyroidism plasma concentrations of mg and inorganic p as well as ca were increased a greater accumulation of ca occurred in some tissues and a lesser accumulation in others than in acute hypercalcemia of comparable severity and the fractional rate of exchange of tissue ca was 30 more rapid than in control and acute hypercalcemic dogs bone exchange of ca was not significantly increased cell mg concentrations were not appreciably altered by hyperparathyroidism except for a significant 9 decrease in myocardium but the fractional rate of exchange of tissue mg was increased acidsoluble p concentrations were decreased in 3 tissues and na and c1 concentrations were decreased by 10 to 25 in 4 tissues in hypoparathyroidism in addition to a decreased plasma ca the increment in plasma inorganic p that usually occurs after renal pedicle ligation was 75 less than in control dogs cell ca concentrations were decreased by 10 40 but the fractional rate of exchange of tissue ca was unaltered although cell mg concentrations were unaltered a 40 increase occurred in the exchangeability of skeletal muscle mg tissue na and c1 concentrations were decreased by 20 in 2 tissues it has been previously reported that hypercalcemia increases cell ca concentrations by raising the extracellular ca concentration gradient evidence has also been presented that hypercalcemia directly inhibits cell influx of mg and na and cell efflux of k with altered parathyroid activity 2 types of effects are observed those which are dependent upon an abnormal extracellular ca concentration and those which appear to be due to intrinsic effects of parathormone on cell cation transport the present data are compatible with the hypotheses that parathormone stimulates bidirectional transport of cell ca and p stimulates cell influx of mg and opposes the effects of hypercalcemia on cell transport of univalent ions
MED	the inhibition of respiration and phosphorylation in kidney mitochondria by parathyroid hormone administered in vivo parathyroid hormone administered in vivo to rabbits produced a metabolic alteration in kidney cortex mitochondria evidenced by diminished respiratory rate respiratory control and p o ratio with a series of substrates including pyruvate plus fumarate succinate ketoglutarate malate citrate and isocitrate the adenosine triphosphate inorganic phosphate exchange reaction rate was decreased and adenosine triphosphatase activity was increased compared to control mitochondria these changes did not become apparent until about 12 hr after injection were undiminished by 24 hr and could be elicited with as little as 200 usp units of hormone under identical conditions liver mitochondria were unaffected diphospho  and triphosphopyridine nucleotides in combination frequently elevated the respiration in parathyroid treated mitochondria close to or above control levels with citrate and isocitrate but not with the remaining substrates and had no effect on respiratory control with any of the substrates the effects of the hormone could not be duplicated by elevating and maintaining in otherwise normal rabbits serum ca concentrations at twice normal level for 6 hr it is concluded that the effects produced by parathyroid hormone on kidney are multiple in nature and related to the ca raising potency of the preparations
MED	sudden hypocalcemia in normal and hypoparathyroid subjects serum calcium concentration was suddenly decreased in 10 normal and 4 hypoparathyroid subjects by the infusion of 50 mg kg of disodium edta over a 30  to 45 minute interval the return rate to pre infusion values of the serum calcium concentration was the same in both groups serum phosphate showed a marked transient decrease 30 min after the infusion in normal individuals but not in those with hypoparathyroidism the hypophosphatemia was followed by a marked increase in phosphate clearance in the normal group and a decrease in the hypoparathyroid group urine phosphate urine creatinine x 10 up uc x 10 and urine phosphate urine osmolality x 10 up uo x 10 ratios also reflected an increased phosphate excretion in the 2 groups a simple clinical measure of parathyroid function is suggested by determining the up uo x 10 or the up uc x 10 or both ratios before and 3 to 6 hr after intravenous infusion of disodium edta
MED	parathyroid function in chronic renal failure a statistical survey of the plasma biochemistry in azotaemic renal osteodystrophy a collection has been made of 134 personal and published cases of azotemic osteodystrophy in which adequate information was available concerning the pathological state of the bones measurements were available of the plasma calcium plasma phosphate and blood urea nitrogen in all cases and of plasma bicarbonate and plasma proteins in a representative sample the plasma levels of calcium and phosphate in the whole series of 134 cases were not related reciprocally but were correlated directly these data were further analyzed by allocating each case to either of 2 sub groups according to the type of pathological lesions present in the bones in one group there was evidence of defective mineralization of skeletal tissues in the form of either rickets or osteomalacia and the plasma calcium was found to be statistically sub normal in the other group there was no primary defect of mineralization but the lesions of generalized osteitis fibrosa were present and the plasma calcium was statistically normal there was no significant correlation between the plasma levels of calcium and phosphate in either sub group and the plasma phosphate was significantly higher in the group with the higher plasma calcium levels the data indicate that in patients with renal osteodystrophy contrary to general belief the plasma calcium varies independently of the plasma phosphate since these results imply differences in parathyroid function among patients with azotemic osteodystrophy a survey has also been made of the recorded parathyroid weights in chronic renal failure generalized osteitis fibrosa and the accompanying normal levels of plasma calcium are associated with greater parathyroid hypertrophy than is found in most cases of chronic renal failure or cases with defective mineralization the various data are interpreted in relation to the known metabolic disturbances and natural history of azotemic osteodystrophy by analogy with states of simple vitamin d deficiency it is suggested that hypocalcemia and relative unresponsiveness to the calcemic action of parathyroid hormone are related to an acquired resistance to vitamin d the group of cases with statistically normal plasma calcium prove that the parathyroid glands can function effectively in some patients with chronic renal failure irrespective of the level of the plasma phosphate the size of the glands and the effects of sub total parathyroidectomy in patients of this group suggest that the normal plasma calcium results from an increased production of parathyroid hormone the more advanced renal failure in the normocalcemic as compared with the hypocalcemic cases could mean that the development of an effective degree of secondary hyperparathyroidism is a function of the duration of the renal disease it seems likely that when the parathyroid response is sufficient to overcome the effects of the vitamin d resistance it also entails the development of generalized osteitis fibrosa healing of the defect of mineralization and increased liability to metastatic calcification
MED	albrights hereditary osteodystrophy report of a family with studies of bone remodeling two members of a single family each representing different forms of albrights hereditary osteodystrophy have been presented the kindred pattern is similar to those of other reported families and is consistent with a sex linked or autosomal dominant mode of inheritance the importance of a course of intramuscular parathyroid extract for proof of parathyroid hormone resistance is emphasized biopsy specimens of rib labeled in vivo with tetracycline were studied microscopically these new observations indicated cellular defects in bone remodeling shared by the propositus and case 2 which may explain the low rates of bone turnover found in each immunologic studies established the presence of a substance antigenically similar to parathyroid hormone in the parathyroid tissue of the propositus the pathogenesis of albrights hereditary osteodystrophy and atypical forms of parathyroid hormone resistant hypocalcemia is discussed
MED	acute hyperparathyroidism a surgical emergency acute hypercalcemic crisis of hyperparathyroidism is a surgical emergency diagnosis is often difficult because of the polymorphous character of the symptoms the variable clinical features of the syndrome are described emphasizing the frequent occurrence of gastrointestinal symptoms especially duodenal ulcer of recurring pancreatitis in the antecedent history as well as the better known occurrence of renal and skeletal manifestations which precede the crisis in all but a few cases despite the variability of the clinical manifestations the total syndrome forms a distinctive pattern which should be recognizable once it is known previously reported cases have been reviewed and an additional case reported the differential diagnosis aids in identification of the tumor and prospects for more effective control of the hypercalcemia are discussed at the present time early surgical removal of the tumor is the only effective treatment
MED	actinomycin d inhibition of intestinal transport of calcium and of vitamin d action actinomycin d injection inhibits the actions of vit d in increasing concentrative transport of ca across the intestinal wall in vitro and in raising serum ca concentrations of fasted vit d deficient rats actinomycin d blocks the transport of ca across the mucosal surface of vit d deficient as well as vit d treated rats so that its action is on the ca transport system rather than on the stimulatory effect of vit d this inhibitory effect of actinomycin d on ca transport is present within 3 hr of its s c injection and is less marked at 18 hr which suggests a direct interaction with the ca transport system under the same conditions actinomycin d does not influence the transport of 1 tyrosine across the intestinal wall in vitro
MED	studies on hydroxyproline excretion and corticosteroid induced dwarfism treatment with human growth hormone two children who had been receiving large doses of corticosteroids for years and were growing at a retarded rate were treated with human growth hormone growth rate increased 2 5 to 3 fold and urinary hydroxyproline excretion which was initially low increased to the normal level when treatment was stopped growth rate and hydroxyproline excretion decreased promptly
MED	a comparison of human placental lactogen hpl and human growth hormone hgh in hypopituitary patients the conclusions based on the studies reported are that placental lactogen hpl at a dose level of 200 mg day did not induce a positive nitrogen balance in two hypopituitary subjects in addition lactogen does not augment the nitrogen retaining effect of growth hormone when given in a dose of 200 mg day
MED	radiation necrosis of the brain in acromegaly radiation therapy of pituitary tumors can cause necrosis of the brain 4 cases are reported particulary if a carefully considered schedule of dosimetry is exceeded the error can be due to repeated courses of treatment or too rapid administration the cerebral lesions develop after a latent period of months and are progressive and often fatal appropriate pituitary surgery is preferable to multiple treatment with radiation
MED	experiences with hgh treatment of twelve hypopituitary dwarfs for periods varying from 6 to 41 months are reported all the patients were considered to have hypopituitarism from birth four of them of the hereditary type four possibly due to traumatic birth or neonatal asphyxia and four from an unknown cause in six patients detailed information concerning growth during the first year of life could be obtained all of these patients had a degree of growth retardation before one year of age we consider this to be the rule rather than the exception in pituitary dwarfism the most important diagnostic evidence was a marked degree of growth retardation accompanied by a pronounced delay in skeletal maturation and in most cases signs of secondary hypothyroidism increased insulin sensitivity and a poor response to metopyrone administration none of the patients who had passed the normal age of puberty had maturated sexually all twelve patients responded well to hgh therapy during the first year of treatment the average height increment was 10 cm catch up growth with continued treatment a normal rate of growth about 6 cm year was obtained there was no disproportionate acceleration of skeletal maturation in any of the patients none of them has so far become resistant to hgh administration the oldest patient has reached normal height whether this will be possible not only in the moderately severe but also in the most severe cases of pituitary dwarfism can not yet be stated the possibility of using human gonadotrophic hormones in an attempt to produce sexual maturation in these patients is discussed briefly
MED	treatment of retarded growth with human growth hormone results of treatment with human growth hormone in the following 3 cases are discussed female hypopituitary dwarf of 17 yr who grew 10 cm in 20 mth a boy of 14 yr with constitutional retarded growth in whom the growth rate increased and in a case of primordial dwarfism in a girl of 10 yr in whom the growth curve was unaffected by the treatment
MED	genetic pituitary dwarfism with high serum concentration of growth hormone new inborn error of metabolism a description is given of three siblings with hypoglycemia and other clinical and laboratory signs of growth hormone deficiency but with abnormally high concentrations of immunoreactive serum growth hormone since exogenous growth hormone was active in these patients the endogenous secretion of an abnormal growth hormone molecule is postulated
MED	growth hormone deficiency in man an isolated recessively inherited defect a deficiency of human growth hormone not associated with other pituitary deficiencies was observed in midgets with sexual ateliosis a form of dwarfism inherited as an autosomal recessive trait body proportions sexual development birth weight and postpartum lactation are normal in this syndrome
MED	treatment of short stature in children and adolescents with human pituitary growth hormone raben experience with thirty five cases human pituitary growth hormone raben was evaluated by longitudinal study of growth as a therapeutic agent in the treatment of short stature clinically significant increases in growth rate were achieved in 11 of 13 hypopituitary patients no significant improvement in linear growth rate was noted with a dose of 2 mg 3 times weekly in children whose short stature was due to other conditions no adverse reactions were noted thyroidal adrenal or gonadal activation was not observed growth was stimulated probably without an undue increase in bone age though this point demands continued scrutiny owing to the limited supply of this material it is recommended that it be used only in cases of documented growth failure and a protocol for evaluation of therapeutic response is discussed though not a panacea for treatment of short stature human growth hormone fulfils a unique and invaluable role in replacement therapy for the hypopituitary dwarf
MED	the development of bilateral adenomatous adrenal hyperplasia in a case of cushings syndrome of eighteen years duration a case of cushings syndrome of 18 years duration is presented the disease began when the patient was 8 years old and was partially controlled by pituitary radiation when she was 13 however clinical evidence indicate low grade but continuous adrenocortical activity for the next 13 years the probable suppression of gh secretion by the increased steroid levels during her growth period provides a reasonable explanation for the dwarfism of the patient the administration of 8 mg of dexamethasone per day failed to decrease urinary steroid excretion bilateral nodular hyperplasia was found at surgery it is suggested from the evidence presented that this patients disease began first as a primary pituitary process but during the long duration of the acth secretion it evolved into one of autonomously functioning bilateral nodular hyperplasia
MED	hypopituitarism a study of growth hormone and other endocrine functions pituitary function was evaluated in 25 adults with evidence of hypopituitarism or enlargement of the sella turcica growth hormone secretory function was measured by radioimmunoassay of plasma samples taken before and after insulin induced hypoglycemia in a standardized test of growth hormone reserve all patients exhibited significant defects in growth hormone secretion as indicated by the failure of this hormone to rise to normal levels in response to hypoglycemia the order of frequency of hormonal loss was growth hormone gonadotropin adrenocorticotropic hormone thyroid stimulating hormone no pattern of deficiency was characteristic for any particular etiology of hypopituitarism one patient with asymptomatic enlargement of the sella turcica accidentally discovered had an isolated loss of growth hormone secretory capacity two patients in the series demonstrated intrinsic deficiency of thyroid as well as pituitary secretion and both had elevated liters of antithyroid antibodies this study represents the first direct evaluation by radioimmunoassay of growth hormone function in a series of hypopituitary adults it demonstrates a remarkably high prevalence of growth hormone loss and suggests that the growth hormone response to hypoglycemia may be one of the most sensitive tests for the diagnosis of hypopituitarism
MED	hypoglycemia and dwarfism associated with the isolated deficiency of growth hormone the authors have studied a 7 year old dwarfed boy with a history of severe recurrent hypoglycemic episodes since age 1 and retarded bone age hepatic adrenal and thyroid function were normal he demonstrated fasting hypoglycemia with blood sugars of 30 40 mg 100 ml he was not sensitive to l leucine but showed insulin sensitivity and hypoglycemic unresponsiveness glycogenolysis in response to both adrenaline and glucagon was appropriate fasting plasma gh levels were less than 1 m g ml normal 1 3 and no rise was seen after insulin induced hypoglycemia similarly these low gh levels did not rise 3 6 hr after a glucose tolerance test treatment with hgh reversed the alterations in carbohydrate metabolism it is concluded that the patient suffered from an isolated gh deficiency which resulted in dwarfism and alterations in carbohydrate metabolism
MED	the effect of growth hormone in hypothalamo pituitary dwarfism i the metabolic effects of human growth hormone human growth hormone isolated by rabens method was given in 2 to 5 mg daily doses over periods from 1 to 12 days to 7 patients with pituitary hypothalamic dwarfism the metabolic effects were as follows nitrogen retention with a variable reduction in blood urea the plasma amino acid concentration did not alter after i m injection of the hormone during fasting an accompanying retention of intracellular components in such proportions required for protoplasm formation isotonic expansion of the extracellular compartment without change in the plasma electrolyte concentrations retention of phosphorus sometimes a rise in plasma phosphate increased intestinal calcium absorption hypercalciuria no alteration in plasma calcium an increase in plasma citrate and citrate urinary excretion the calcium and phosphate retention was reversed on stopping treatment mobilisation of fat stores with lipid catabolism this was accompanied by a well marked increase in nefa concentration for some hours after hormone injection in the fasting state after a period of hypoglycaemia and low nefa levels a complex biphasic action on glucose metabolism fasting blood sugar levels are altered as are the glycaemia in various tests such as fasting insulin injections tolbutamide administration intestinal hyperglycaemia acceleration of intermediate metabolism with increased blood citrate concentrations and 24 hours urinary excretion of  ketoglutaric acid in one test during fasting the blood citrate increased 4 hours after hormone injection after an oral load of sugar the blood citrate and  ketoglutaric acid concentrations did not alter a progressive gain in weight has been found during treatment partly reversible on stopping treatment correlating with the intracellular nitrogen retention and expansion of the extracellular space despite mobilisation of fat reserves
MED	serum chorionic growth hormone prolactin and serum pituitary growth hormone in mother and fetus at term chorionic growth hormone prolactin cgp and pituitary hgh were measured in maternal and fetal blood obtained simultaneously at term from 29 pregnant women and their fetuses utilizing sensitive radioimmunoassay procedures the mean concentration of serum cgp in maternal venous blood was 5 6 g ml sem0 39 whereas in umbilical venous serum the mean concentration was 0 019 g ml sem 0 003 a 300 fold difference contrariwise the mean concentration of serum hgh in maternal serum was 5 9 m g ml sem 0 52 and in umbilical venous serum the level was 33 5 m g ml sem 4 6 the ratio of serum cgp hgh in maternal venous serum was 1076 in contrast to 0 57 in umbilical venous serum the findings strongly suggest that cgp is secreted by the syncytiotrophoblast almost exclusively in a unidirectional manner into the maternal circulation further it is unlikely that an appreciable exchange of hgh occurs between the maternal and fetal circulations the data support the view that the growth hormone like metabolic changes observed in pregnancy are attributable to the effects of cgp and are consistent with the hypothesis that cgp is an important metabolic hormone of pregnancy exerting its actions on the mother and possibly the placenta but only indirectly on the fetus
MED	effect of abdominal operation on glucose tolerance and serum levels of insulin growth hormone and hydrocortisone abdominal operations of moderate severity are followed by high fasting blood glucose levels and a reduced tolerance to intravenous glucose which persists for at least 72 hours after operation fasting plasma insulin levels are raised after surgery intravenous glucose produces much higher levels of serum insulin and growth hormone in the immediate postoperative period corticotrophin infusion increases the plasma hydrocortisone levels and reduces glucose assimilation to a greater extent than operation but has no effect on serum insulin or growth hormone levels
MED	plasma growth hormone concentration in the rat determined by radioimmunoassay influence of sex pregnancy lactation anesthesia hypophysectomy and extrasellar pituitary transplants the assay used is described in detail several experimental conditions were studied both to validate the method and to determine factors which regulate gh secretion in this species in fasting sprague dawley rats weighing 150 200 g mean plasma gh concentration in females was 94 2 17 3 and in males 54 9 12 0 m g ml gh levels in lactating rats were determined to be in the normal range for females thereby providing evidence that this assay does not detect prolactin gh levels were not elevated in pregnant rats hypophysectomy led to a fall below detectable levels of gh intraocular pituitary transplants failed to raise gh levels in hypophysectomized hosts gh levels in male but not in female rats are depressed by brief periods of ether anesthesia these findings and the results of pituitary transplantation experiments are further evidence that the nervous system is involved in the regulation of gh secretion
MED	clinical features of the alalies russian the term alalies is applied to the various states of absence or insufficient development of speech in children resulting from defective development or affections of the speech centers before the development of speech from the clinical study it is possible to distinguish between several forms motor sensory and semantic alaly with signs of amnesia the causes are multiple trauma perinatal cerebral hemorrhage inflammatory processes metabolic disorders before the development of speech and alimentary and trophic disorders the alalies show varying degrees of severity in most children suffering from alaly neurological signs can be demonstrated on the right side an indication of the organic nature of the condition the presence of local symptoms in the various forms of alaly is often associated with signs indicating involvement of adjacent regions of the cerebral hemispheres in the pathological process which would explain why the alalies are often complex the character of the alalies depends on functional disorders resulting from the lesion in the frontal anterior motor temporal or parietal region of the dominant cerebral hemisphere patients with alaly often show neurotic reactions resulting from the disorders of the processes of inhibition and excitation of the cerebral cortex and the subcortical formations early treatment of the alalies with drugs combined with logopedic and pedagogic measures gives good results
MED	an unusual form of acquired aphasia in children an unusual form of acquired aphasia both receptive and executive is described as occurring in 10 children 6 girls and 4 boys the onset occurred between 5 and 6 yr of age with one or more epileptiform attacks which were not repeated but were followed by some degree of hearing loss later improving failure to comprehend spoken language and finally loss or impairment of executive speech examination of csf and peg yielded normal results eegs were abnormal mainly in the temporal leads the disorder appeared self limiting and throughout non verbal intelligence was not imparied
MED	childhood echolalia in delayed psychotic and neuropathologic speech patterns some linguistic analytical procedures and preliminary findings from controlled tape recorded samples of a group of echolalic children are reported together with the clinical and experimental rationale for the investigation the subjects are echolalic 3 yr olds and a group of young clinical referrals representing a variety of pathological conditions variables selected for study include the proportion of echo to non echo and silence the quality and appropriateness of the non echoed speech the amount of the stimulus echoed the nature of the triggering stimulus the deviation of echo pattern from stimulus pattern pitch loudness time variations and the childs chronological and mental ages early quantitative results yielded very similar echo non echo silence percentages with echolalia representing a mean of about 40 of the conversation of each experimental group
MED	speech as a landmark in development it is attempted to demonstrate how observations of childrens speech and language development may serve as valuable indicators of their general physical intellectual and emotional progress speech lag or breakdown may corroborate other suspect areas of development or may point the way to them speech and language disorders seldom originate in the mouth ideas must precede speech and speech is a direct correlate of intelligence
MED	the applicability of individualized programed instruction in the education of deaf children verbal behavior is learned behavior and as such is guided by the same principles as any other learned behavior the parents role is mainly to help the young deaf child conceive of language as a socializing process and to help shape language behavior toward the use of verbal symbols the teachers role in the deaf childs progress as a language user includes 1 helping the child discover how the structure of his language operates and 2 guiding him in the process of acquiring clear concepts the learning of a language is a highly individualized process and requires thousands of hours of practice efficiency in language teaching to the deaf has not been generally achieved by traditional methods the teacher of the deaf needs extra help in order to provide the individualistic kind of teaching to insure verbal over learning by the child self tutoring programed materials offer this help programs are so constructed that a child proceeds through the program step by step with a probability of maximum success because of constant feedback as to correctness of his responses for younger children the use of a machine seems desirable while for older children the program may appear in book form on film strip and any other visual medium well constructed programs should be correlated with classroom instruction
MED	the impact of individual differences on language learning a matrix of extrinsic and intrinsic factors affecting language learning in the prelingually deaf child is considered particular emphasis is placed on the effects of parental attitudes on both the emotional stability of the home and on the provision or restriction of experience
MED	the oral language performance of premature children and controls fifty one premature children born in 1955 and 1956 were compared with 55 normally born subjects with birth weights over 2 500 grams they were tested on tapped patterns auditory memory span auditory discrimination word recognition language comprehension articulation resistance to articulation disintegration word finding story telling number of words used mean length of 5 longest sentences sentence elaboration grammatical errors definitions and categories the mean age of both groups was 5 8 and the premature childrens performance was inferior to that of children born at term
MED	speech and reading problems in childhood the following communicative disorders have been discussed functional articulation defects delayed speech development stuttering hearing loss cleft palate neurological disorders and reading disorders these disorders rarely have a single cause they are the result of an intermingling of many factors some physiological and some psychological some residing within the child and some in the parents and environment in general delayed or defective speech is a cause for great concern to most parents and teachers the public health worker who listens with an attentive and sympathetic ear may allay some of this anxiety and thus help foster healthy emotional development in the child the existence of a more serious condition underlying the presenting communication problem even if sensed by the parents is frequently denied the public health worker can assist the parents in the painful process of facing up to their fears a child with a communication problem is still a child and the public health worker by simply reflecting this to the parents and advising them on normal child raising practices can again be of help to the child children with speech deviations are exposed to an overabundance of well intentioned speech correction at home most of it is ineffective some of it unfortunately is harmful while the worker may not be in a position to offer specific advice on a particular child the manner in which the parents and teacher are handling the childs communication problem can be explored and damaging practices possibly eliminated the fact that there may be a diagnostic and treatment center to which the child can be referred does not vitiate the public health workers role the public health physician and public health nurse have a valuable contribution to make in helping the parents school and child accept the chronic nature of the disorder
MED	disorders of communication in young children the normal development of spoken language is outlined the causation differential diagnosis individual assessment and management of developmental disorders of communication in young children are briefly discussed
MED	acquired aphasia in children this report concerns the cases of 21 boys and 11 girls studied over a period of several years while rehabilitation was carried out the general conclusions fall under 3 headings 1 symptomatology as compared with that of aphasia in the adult 2 the course of the disorder 3 prospects of the level of intellectual performance in the future of the children in 13 cases cerebral damage had resulted from traumatic contusion in 10 cases from an intracranial nontraumatic hematoma vascular malformation aneurysm or angioma in 2 cases the aphasia followed operation for a cerebral astrocytoma in 2 further cases occlusion of the left middle cerebral artery had occurred and in the remaining 5 cases no precise diagnosis was made
MED	the causes of delayed development of speech speech develops parallelly and simultaneously with psychophysical development of the child arising from internal need and under the influence of external factors not all children are given the chance to develop in favorable conditions and to pass through all the phases of development without some injury the various possibilities when a child may be injured and hampered in the development of speech are discussed the testing of the sense of hearing in children with a cleft palate is also included out of 181 cases of cleft palate in 72 cases there was decrease of the sense of hearing exceeding 30 db this additional injury of the child with a cleft palate if remaining unnoticed may make the treatment of speech abnormality difficult the necessity of diagnostic team investigation and the treatment of children with speech disturbances are emphasized
MED	concept learning in culturally disadvantaged children as a function of verbal pretraining while research indicates that verbal pretraining has a positive influence on the discrimination learning performance of subjects of normal intelligence a comparable influence has not been shown for other types of conceptual tasks for retarded subjects the purpose of this experiment was to investigate the effects of stimulus pretraining on concept learning by subjects who had a high risk of being classified as mentally retarded at some future time a group of 27 higher risk and 27 lower risk subjects was randomly divided into 3 pretraining groups verbal label attention and control subsequent to pretraining on the stimuli used for transfer task 1 subjects in each group were presented with a concept learning task transfer task 1 after reaching the criterion of learning on transfer task 1 subjects were presented with a second new concept learning task analysis of the data revealed that there were no significant performance differences between risk groups and that pretraining had a significantly positive effect on performance
MED	concept development and language instruction the author describes factors related to and the errors that may occur in concept development in children the contributions of language for the deaf childs conceptual development are stressed included are a review of what concepts are psychologically and an example of how concepts may be presented educationally in the classroom
MED	formal speech characteristics as a diagnostic aid in childhood psychosis the frequency of use of various grammatical units in the spontaneous conversational speech of adults and children has been noted by many authors to be fairly stable the hypothesis that idiosyncratic distributions might be found in certain specific disorders of ego functioning was tested in relationship to childhood psychosis some support was found for this as well as for some contemporary psychological and psychoanalytical interpretations of phenomena seen in childhood psychosis
MED	cerebral dominance and speech acquistion in deaf children in examining the prediction that left cerebral dominance as indexed by hand and sighting preference should be a positive accompaniment of speech learning in individuals whose cerebral speech areas are likely to be in the left hemisphere it was found that over a 10 12 year period of formal education right handed right sighting deaf students consistently earned higher speech grades than their right handed left sighting and right handed mixed sighting counterparts matched on the basis of hearing loss this finding supports the hypothesis that the cerebral mechanisms relevant to speech acquisition are simplified facilitated and or less prone to interference when control of speech hand and eye is localized primarily in 1 hemisphere of the brain
MED	a color test for the measurement of antibody to the non acid forming human mycoplasma species a metabolic inhibition test for the measurement of growth inhibiting antibodies to the non acid producing human mycoplasma species is described the test is based upon the ability of these organisms to metabolize arginine with a resultant alkaline shift in the ph of the medium the alkaline shift is inhibited by specific antiserum labile accessory factor s present in unheated guinea pig serum potentiates the inhibitory effect of antiserum the test is sensitive and specific for the measurement of antibody to mycoplasmas in rabbit immune and human convalescent serum
MED	serologic epidemiologic studies with m pneumoniae i demonstration of an hemagglutinin and its inhibition by antibody a new direct specific hemagglutination reaction with live m pneumoniae is described this requires the presence of a natural antibody for the red cell in the horse serum employed in the diluent although vervet monkey erythrocytes generally have been employed human and rabbit cells may be used hemagglutination can be inhibited by specific antibody but heat inactivation of the sera is required whether they be human or animal in origin antibodies persist for many years and are passively transferred to the fetus a micro variation has been devised the test is useful for diagnostic and epidemiologic studies and in reverse can be utilized for the rapid serologic identification of new isolates the method is limited at present to m pneumoniae
MED	serologic epidemiologic studies with m pneumoniae ii prevalence of antibodies in several populations the prevalence of antibodies for m pneumoniae was determined in 6 populations by means of a new serologic test among members of a population of normal families no one under age 15 had antibodies none of the latter acquired an infection during the following year of 67 children in a home only 3 had antibodies the 7 cottage mates of one of these children who had acquired an infection remained uninfected in a group of 124 elderly persons 65 53 had antibodies a similar proportion of 76 persons attending a rheumatic fever prophylaxis clinic was positive in this population it was demonstrated that antibodies could persist in undiminished titer for at least 10 yr of 169 point barrow residents 68 had antibodies above age 15 the rate was approximately 90 two companies of naval recruits who had similar positive antibody rates at the beginning of training acquired antibodies in rather divergent patterns 63 in one and 26 in the other m pneumoniae infections seem to be sporadic and to produce epidemics only infrequently in civilian populations
MED	growth and survival of mycoplasma neurolyticum in liquid media maximal growth of m neurolyticum between 10 and 10 colony forming units ml was obtained after 3 days of incubation at 36 c in broth media containing 10 agama horse serum when whole horse serum was used in the medium a complement mediated inhibition was observed this inhibition could only be detected when growth was followed by daily plate counts maximal growth was delayed for about 24 hr by the horse serum and the inhibition was spontaneously reversed at the temperature of incubation penicillin g was also found to have a temporary inhibitory effect this was detected with as little as 40 units ml maximal growth was delayed until the 6th day of incubation when 200 units ml was present and until the 16th day when 1 000 units ml was present the survival of m neurolyticum at undetectable levels in cultures during the incubation period presented an eclipse phenomenon which has not been explained the recrudescence of growth in such cultures late in the incubation period illustrates the events which may occur when mycoplasmas are isolated from clinical material by prolonged incubation in the presence of inhibitors survival data showed that m neurolyticum had greatest stability at ph 8 0 with reduced viability at ph 9 0 7 0 10 0 and 6 0 in that order the data on growth and stability suggest a close relationship between the species of mycoplasma studies and bacteria
MED	hela cells resistant to bromodeoxyuridine and deficient in thymidine kinase activity mutant sublines of hela s3 cells resistant to growth inhibition by bromodeoxyuridine budr have been isolated the resistant cell lines hela bu 10 hela bu 15 hela bu 25 hela bu 50 and hela bu 100 proliferated in the presence of 10 15 25 50 and 100 mg ml budr respectively extracts from hela bu 25 hela bu 50 and hela bu 100 cells exhibited 2 5 of the thymidine h deoxyuridine h and bromodeoxyuridine h phosphorylating activities of parental hela s3 cells hela bu 10 and hela bu 15 cell extracts were also deficient in thymidine kinase activity yielding approx 43 and 8 respectively the thymidine kinase activity of parental hela s3 cells the deficiency in thymidine kinase activity of hela bu 100 cells was not due to negative feedback inhibition by high levels of budr or to interference with the thymidine kinase assay by inhibitors or competing enzymes in the hela bu 100 cell extracts following 5 weekly passages in media lacking budr the hela bu 100 cells did not exhibit increased thymidine kinase activity moreover mixtures of extracts from hela s3 and hela bu 100 cells displayed a thymidine kinase activity equivalent to the sum of the activities or extracts prepared respectively from the hela s3 and hela bu 100 cells radioautographic studies have shown that after hela s3 cells were incubated for 6 hr with thymidine h 35 45 of the nuclei were heavily labeled with radioactivity however fewer hela bu 100 cells displayed labeled nuclei and the nuclei were only lightly labeled hela bu 100 cell extracts contained normal amounts of thymidylate synthetase thymidilate kinase and uridine kinase activities following infection by vaccinia virus high levels of thymidine kinase activity were induced in hela bu 100 cells
MED	a note on the taxonomic status of strains like campo hitherto classified as mycoplasma hominis type 2 the classification of strains similar to mycoplasma strain pg 27 of campo as myc hominis type 2 should be withdrawn these strains have now been identified as myc arthritidis
MED	chromosome studies of human cells infected in utero and in vitro with rubella virus a cytologic study of metaphase chromosomes was undertaken to determine if damage to the genetic apparatus of human cells may be induced by rubella virus and whether such damage produces the pathology seen in newborns from mothers infected early in pregnancy fibroblast cell strains were initiated in vitro from embryonic material obtained by therapeutic abortion of fetuses from rubella infected mothers embryonic material from spontaneous and non rubella therapeutic abortions yielded similar cell strains for infection in vitro the results from both types of studies were as follows a virus shedding cell strains were obtained from all types of organs cultivated which indicated wide dissemination of virus in the fetuses from rubella infected mothers b chronic infection could readily be established by in vitro infection and no cytopathic effect was noted c although many strains continued to shed virus throughout months of in vitro cultivation no changes in growth properties occurred with the exception that infected strains from lung tissue showed limited growth capacities d from observations of over 2 000 metaphases neither obvious chromosomal rearrangements nor non disjunctional changes were observed in strains infected naturally or experimentally e among 17 rubella abortion derived cell strains there was a marked elevation in frequency of chromosome breakage in 3 instances 18 29 68 f a correlation between virus shedding in vitro and increased chromosome breakage was noted although this was not complete g the combined average frequency of chromosome breakage in one set of 7 rubella abortion strains was 18 in the other set of 9 abortus strains 9 8 h similarly a slight but significant elevation in average chromosome break frequency 9 8 was obtained in four cell strains which had been experimentally infected in vitro with rubella virus uninfected cells 5 2 although effects upon the chromosomes were demonstrated these were restricted to slight general elevations in frequency of breakage above normal values very high increases in breaks were sporadic it appears more likely that the general fetal abnormalities associated with rubella infection in vivo result from possible effects of the virus upon growth rather than from effects upon the chromosomes however the studies were restricted to fibroblasts cultured in vitro and effects on other types of cells may have greater implications for this question
MED	fine structure of staphylococccal l forms l forms of staph aureus and bacterial cells were processed by the same technique for electron microscopy ultrathin sections allowed comparison of structural units and indicated that staphylococcal l form units of all sizes lack the rigid cell wall and the compact fibrillar nuclear area of bacterial cells the l form units are bound by a typical trilamellar membrane comparable to that described for mycoplasma species nuclear areas in staphylococcal l forms present a diffuse appearance and could not be correlated with size of any particular structural unit many small units were seen within large bodies and possibly are involved in the reproductive process no evidence of division by formation of septa or by pinching off of cytoplasmic fragments was obtained from the electron micrographs
MED	respiratory virus vaccines ii mycoplasma pneumoniae eaton agent vaccines purified and concentrated formalin killed vaccines were prepared from m pneumoniae propagated in serum free artificial medium the vaccines were aqueous or were incorporated in alum or emulsified peanut oil adjuvant 65 adjuvant two or 3 different concentrations of mycoplasma were included in each preparation serum neutralizing and cf antibody responses were measured in hamsters monkeys and in institutionalized persons following 1 2 3 and sometimes 4 vaccinations all of the preparations were highly antigenic in animals and in man alum vaccines were better than aqueous vaccines and those in adjuvant 65 appeared to give best results although the bleeding times were not always optimal for demonstrating maximal effect persons who were without detectable antibody initially and thus would be most vulnerable to infection gave better responses to the vaccine than did those with pre existing antibody alum vaccine is an acceptable formulation for use in man and only 2 doses of such vaccine were necessary to induce neutralizing antibody in 90 of the persons who were initially without detectable antibody no local or systemic reaction of clinical consequence was noted in any of the persons vaccinated recent unpublished findings which indicate a high degree of effectiveness of the alum vaccine in stimulating antibody in preschool children and in protecting children and adults against the natural disease are mentioned
MED	isolation of mycoplasma pneumoniae from adults with respiratory infections isolation of mycoplasma organisms from the sputum was attempted in 254 patients with various syndrome of respiratory disease isolates were obtained in 56 of the 197 patients with pneumonia 50 of patients with chronic bronchial diseases who were not treated with tetracycline and 33 of persons with acute upper respiratory infection these differences are not statistically significant and indicate a nonpathogenic role for m pharyngis and m salivarium which were the strains most frequently isolated the highest frequency of isolation was from males 15 to 30 yr of age isolation of m pneumoniae requires one to 2 weeks therefore it is not useful for rapid diagnosis also it underestimates the prevalence of infection especially if patients have received tetracycline of the serologic tests complement fixation cf was the most specific the growth inhibition test tri was the most sensitive and was significantly related to atypical pneumonia the 2 tests may measure different antibodies against m pneumoniae serum cold agglutinins developed in many cases of pneumonia and were poorly discriminatory in etiologic diagnosis m pneumoniae infection occurred in a minimum of 8 and a maximum of 20 of civilian patients hospitalized for pneumonia during the season studied serologic evidence for m pneumoniae was rare in lobar pneumonia in nonlobar pneumonia m pneumoniae accounted etiologically for 13 to 50 of cases the incidence of m pneumoniae infection was constant in different seasons but greatest relative to the occurrence of pneumonia in the fall and spring
MED	color test for the measurement of antibody to t strain mycoplasmas a metabolic inhibition technique for the measurement of antibody to t strain mycoplasmas was developed based upon the ability of t strain mycoplasmas to metabolize urea with the concomitant production of ammonia and the ability of specific antiserum to inhibit this ammonia production phenol red added to the medium served as an indicator of ph change resulting from ammonia production specific antiserum to t strain mycoplasma t 960 was prepared the t strain organism was shown to be serologically distinct from the recognized large colony mycoplasmas antibody to mycoplasma strain t 960 in human sera was demonstrated with the metabolic inhibition technique
MED	effect of mycoplasma on interferon production and interferon assay in cell cultures the influence of mycoplasma on the production and action of interferon was studied in cultures of both l and human embryonic kidney hek cells m hominis 1 the negroni agent and the f12 mycoplasma were used for infection of l cells and m hominis 1 and m pneumoniae for inoculation of hek cells all strains were capable of multiplication in the culture systems employed none produced detectable levels of interferon and responsiveness of the cells to induction of interferon by virus remained unaltered infection with mycoplasma did not impair the sensitivity of the cells to the action of interferon nor was the replication of vesicular stomatitis virus noticeably diminished
MED	recovery and characterization of a herpes like virus from dog kidney cell cultures a transmissible agent was recovered from primary dktc which developed a spontaneous cpe characterization and serological studies of the virus indicated that the virus was a new member of the herpes virus group
MED	immunopathologic changes in rheumatoid arthritis synovium synovial tissue from 8 children and 7 adults with rheumatoid arthritis was examined for localization of immunoglobulins and complement three cases were found to have c and immunoglobulins within the cytoplasm of synovial cells four cases had discrete localization within the connective tissue stroma the remaining 7 cases demonstrated larger more weakly staining collections which were found more diffusely throughout the synovium no immunoglobulin or complement localization was present in 10 out of 11 additional patients with forms of joint disease other than rheumatoid arthritis correlation of these results with the clinical findings and joint fluid c assays was made
MED	electron microscopic studies of mycoplasma pplo strain 880 in artificial medium and in tissue culture mycoplasma strain 880 isolated from a leukemic patient was studied in broth cultures and in several cell culture lines this strain exhibited considerable pleomorphism in size internal structure and shape including forms with filamentous projections the most common form observed was 0 5 to 1 in diameter and had a nuclear area of fibrillar strands probably dna the cytoplasm of the organisms contained ribosome like granules and a flattened vacuole which indented the nuclear area there were various other forms including elementary bodies 100m in diameter that were very electron dense in the tissue culture lines in which the cells grew as a monolayer the mycoplasma were closely associated with the cell surface and were occasionally seen in membrane lined cytoplasmic vacuoles in cell lines that did not attach to the glass the mycoplasma were fewer and not attached to the cell surface although the ultrastructure of this strain is similar to that of previously described strains there are differences in details of structure which may be related either to the growth conditions used or to characteristics of the strain the various forms of the organism are consistent with the suggestion that mycoplasma may have several mechanisms of reproduction growth the intracellular mycoplasma may be protected from antibiotics this would partly explain the difficulty of eradicating mycoplasma from infected cell cultures
MED	long term prognosis and the response of schizophrenic children to drug therapy a controlled study of trifluoperazine it is evident from this study that treatment and control groups must be matched for severity of illness since this affects the responsiveness to pharmacological as well as to other types of treatments the use of the double blind technique does not of itself guarantee a well controlled study the comparison of 2 or more treatment regimes may be misleading if the groups are not matched or if the matching is not based on critical factors in this study both the response to the nonpharmacologic aspects of treatment and the type of response to the drug itself were related to the initial severity of language impairment thus the major developmental defect which determines long term outcome for schizophrenic children in this group also predicted the immediate responsiveness to treatment within the 2 major prognostic subgroups of young schizophrenic children those with speech and those without are children with different profiles of disordered development and different patterns of assets and handicaps
MED	the long term treatment of a psychotic child in a psychiatric hospital description of one phase of the long term psychotherapy of a 6 yr old psychotic boy within the framework of a mental hospital the first part deals briefly with the lay out and the structure of a new unit for emotionally disturbed children underlining the well known importance of the therapeutic milieu in the treatment and care of the mentally ill particularly important when the patients are children the child presented was diagnosed when admitted as a case of severe childhood psychosis of the autistic type the unusually rich data at disposal were obtained through non verbal communication because the child has no language nevertheless he can express himself clearly through play and gestures the analysis of this precious clinical material focuses the discussion on the existence and the quality of an object relationship preceding the psychosis the importance of the early unusual sensitivities in the formation of a premature and fragile ego and the method of choice in the treatment of childhood psychoses
MED	comments on a case of infantile psychosis an account is given of a case of infantile mutism which depended not so much upon a true autism as on a withdrawing into himself as a defence against a dangerous and threatening environment there was a spectacular and unusual improvement of the symptomatology with psychotherapy
MED	the problems of infantile autism and psychiatric nosology in psychiatric literature the syndrome of early infantile autism has been divided into several subgroups as for instance the subgroup of kanner and the subgroup of asperger and has been assigned to different mental conditions schizophrenia psychopathy neurosis these distinctions and classifications are thought to be controversial so long as the etiology of early infantile autism is unknown nor should any psychiatric school claim to have the right concept of schizophrenia since the etiology of schizophrenia too has not yet been discovered in this particular pre scientific situation of psychiatry it seems more promising to analyze the individual mental case and to concentrate on clinical symptomatology instead of discussing arbitrary nosological entities
MED	families of children with early childhood schizophrenia emotionally disturbed children were divided into 3 groups on the basis of their diagnoses of 1 autism or symbiosis 2 chronic undifferentiated schizophrenia and 3 other forms of emotional disturbance the 3 groups were compared statistically on the following demographic measures 1 educational level of parents 2 occupational level of father 3 prevalence of broken homes 4 male female ratio in each patient group 5 ordinal position among siblings 6 ordinal position among siblings of same sex and 7 age of parents at birth of child results indicated that families of children diagnosed as autistic or symbiotic show many similarities to those with the diagnosis of chronic undifferentiated schizophrenia in general the parents in these 2 groups were better educated and were employed in more highly rated occupations than parents of otherwise disturbed subjects broken homes were prevalent in the group of disturbed nonschizophrenic children but not in the autistic or chronic undifferentiated schizophrenic groups the male female ratio was not significantly different among the 3 groups in the autistic group specifically it was 2 8 1 the data revealed no trend in ordinal position
MED	childhood psychosis a description is given of the diagnostic criteria put forward by creak and her associates in 1961 for what they have called schizophrenic syndrome of childhood psychotic reactions in childhood are grouped into 1 childhood schizophrenia 2 organic states with psychosis 3 mental subnormality with psychosis 4 sensory deprivation 5 neurosis and 6 manic depressive psychosis it is suggested that the generic term psychosis is the best available and a classification is presented and discussed
MED	psychotic reactions of childhood experiences of a mental retardation pilot project clinical team evaluations are presented of a group of 32 psychotic children who were initially thought to be mentally retarded emphasis is placed on consideration of as many aspects of the total picture as possible with diagnosis resulting from a synthesis of the individual pieces of information caution is suggested regarding interpretation of incomplete psychological test findings especially in regard to prognosis the results of this study offer guidelines for differential diagnosis between psychosis resulting from primary emotional disorders and psychosis superimposed on a chronic brain syndrome in children questions are raised about early infantile autism as a unitary syndrome on the basis of etiology the need for a better and more comprehensive diagnostic classification of the psychotic reactions of infancy and early childhood is stressed this must be developed before valid comparisons of treatment and prognostic considerations can be made among groups of clinicians working in the field
MED	modification of autistic behavior with lsd 25 lsd 25 appears to offer a useful adjunct to the psychotherapy of autistic children because of its positive effect in areas which are closely related to the process of psychotherapy a pair of identical male autistic twins was periodically administered 50 of lsd 25 and observed for behavior changes control and drug observations were made while the subjects were placed in a series of standard test situations referred to as the socialization test social isolation test peek a boo pat a cake face to face hand holding and following tests diverse behaviors were recorded in the areas of self stimulatory behavior social interaction and affect recordings were made using an esterline angus multiple pen recorder all behaviors were measured in total time appearance and plotted as percent time in appearance consistent behavioral changes resulted after lsd in that the subjects demonstrated an increase in eye to face contact an increase in laughter and smiling behavior and decrease in self stimulatory behavior
MED	the influence of organic and emotional factors on the origins nature and outcome of childhood psychosis a group of 65 children diagnosed as child psychosis or one of its synonyms was followed up for an average of 15 yr none of the parents were schizophrenic 6 10 had a parent who had psychiatric treatment for neurosis only 2 children had a sib with transient autistic episode none had sibs with the adult type of schizophrenia these findings are felt to militate against the view that child psychosis is part of the schizophrenic group among the 65 children 40 had an i q below 50 40 between 50 and 80 and only 20 above 80 the i q was found in general to be a good predictor of later performances mental retardation is regarded as a primary component of the clinical picture evidence of brain damage was conclusive in 15 children 24 who showed epileptic attacks developing in 10 of them during the follow up speech disorders were the most outstanding manifestation five children had confirmed receptive aphasia and 14 others show some evidence of it in 75 of the speaking children echolalia was noted 11 had abnormalities of delivering spoken words the view that reduction of speech is due to social withdrawal is rejected psychogenic factors and parental attitude were not found to be relevant to the etiology the psychosis is not considered primarily emotional in origin although emotional relationships as well as educational management have considerable influence on the outcome of the disease
MED	compliance and resistance in the conditioning of autistic children an exploratory study twelve autistic children between 4 and 9 yr of age were asked to choose red objects and square objects from a stimulus array ten subjects made correct choices significantly less often than chance that is they avoided emitting correct responses the subjects were given 60 conditioning trials in which choices of either red or square objects were reinforced those who attained either concept subsequently performed perfectly when asked to produce both red and square concepts the other subjects continued giving fewer than chance correct responses thus conditioning trials elicited in some subjects an increased tendency to comply with the experimenters instructions the results suggest that more attention should be paid to the distinction between responses that autistic children are unable to make and responses that they are unwilling to make
MED	the etiology of autistic syndromes of children examination and treatment of 92 children and youths with the autistic syndromes of early childhood over a period of ten years led to the impression that these disorders are a primary organic syndrome of manifold etiology this view is supported by many relevant clinical experiences and data which are discussed in detail
MED	acquisition of imitative speech by schizophrenic children two mute schizophrenic children were taught imitative speech within an operant conditioning framework the training procedure consisted of a series of increasingly fine verbal discriminations the children were rewarded for closer and closer reproductions of the attending adults speech it is found that reward delivered contingent upon imitation was necessary for development of imitation furthermore the newly established imitation was shown to have acquired rewarding properties for the children
MED	hallucinations in children at a state hospital hallucinations in children at referral and upon admission to a state hospital were studied by reviewing randomly selected charts of current patients there were no significant differences in the incidence of hallucinations in boys and girls between racial groups and between schizophrenic children under 12 and over 12 the children diagnosed psychosis with convulsive disorder had the highest incidence of hallucinations 81 those diagnosed childhood schizophrenia had an incidence of 70 and children diagnosed primary behavior disorder had the lowest incidence 35 specific auditory visual and olfactory hallucinations were described the nature of hallucinations in boys and girls was similar psychotic children tended to have more bizarre hallucinations than nonpsychotic children there was no difference in the nature of hallucinations among the different groups of psychotic children although this population consisted of severely disturbed and deprived children who had a high incidence of hallucinations these hallucinations were of simple content and not organized into delusional systems
MED	treatment of childhood schizophrenia a three year comparison of day and residential treatment a carefully designed study of 13 day treatment children matched individually with 13 residential children is presented in each case the diagnosis of schizophrenia was carefully confirmed on the basis of impairment in human relationship disturbance in personal identity resistance to change unusual preoccupations perceptual and cognitive disorders and panic reactions the ages ranged between 6 and 11 the children were selected as the result of matching with regard to age of onset culture and family organization intactness of the family structure was required residential treatment implied round the clock therapeutic interaction with the child for 7 days each week 12 mth of the year day treatment consisted of 9 a m to 4 30 p m care 5 days a week for 9 mth of the year staff distribution was identical in the 2 groups but in the day care group the teacher assumed a larger relative position in the world established for the child all children were matched in ego status at the beginning of the experiment by means of the wisc and psychiatric evaluation changes in this status being measured by the wisc and the metropolitan achievement test series the results indicated no significant improvement in either day or residence in those schizophrenic children who on admission had unscorable wisc tests and who were the most severely impaired in ego structure among the children scorable on the wisc the organic groups in day and in residential treatment showed equivalent degrees of progress the non organic children in residence gave evidence of more improvement than did the matched children in day treatment
MED	visual versus tactual receptor preference in normal and schizophrenic children receptor preferences between visual or tactual stimuli were measured in schizophrenic and normal children 4 pairs of standardized choice situations between visual or tactual stimuli were used with the time of engagement with either stimulus constituting the preference measure schizophrenic children between the ages of 7 and 9 were compared with same aged normal children a group of retardates were used for ma control schizophrenics were significantly lower in visual preference than the same aged normals and an age trend for increased visual preference was found in the normal sample retardates showed greater visual preference than schizophrenics of comparable ma some implications for theory of schizophrenia were discussed
MED	the effect of folic acid on growth and deoxyribonucleic acid synthesis in the rat kidney the effect of a single injection of folic acid 250 mg kg of body wt on growth of the rat kidney was studied the patterns of the response were found to be essentially similar in animals aged between 3 wk and 12 mth maximum values of kidney weight and nucleic acid content relative to body weight were found at 4 days at folate administration the increases in wet and dry weights at this time were approx 80 and 30 resp above the control weights and the percentage dry matter of the kidney was significantly lower than normal during this period at 4 days the rna content of the kidney was also maximal being about 90 greater than the control value and the dna content after 4 days was increased by about 60 whereas the dna values in 6 wk old rats were slightly lower at 7 and 10 days than at 4 days in 12 mth old animals a further small increase was observed at 7 days suggesting a prolongation of dna synthesis in the older animals autoradiographic studies of dna synthesis with thymidine h have shown a greatly increased labeling index in all zones of the kidney following folate injection maximum values were observed at 48 hr in the cortical zone but the patterns of the changes in the medulla were less well defined the labelling indices in the kidneys of 12 mth old rats remained above normal for a longer period than in 6 wk old rats these results concur with the evidence of an increased dna contents of the kidneys of older rats between 4 and 7 days after folate
MED	renal renin in unilaterally nephrectomized hypertensive rats juxtaglomerular index renal pressor activity and width of the zona glomerulosa were normal in unilaterally nephrectomized hypertensive rats maintained on a normal sodium intake increased in those subjected to sodium depletion and decreased in those receiving 1 saline this indicates that renin formation and secretion are most likely the result of the sodium state of the animal rather than loss of a renin stimulating agent in the contralateral or unclipped kidney failure of sodium to influence the degree of hypertension in unilaterally nephrectomized hypertensive rats militates against a direct quantitative relationship between blood pressure and the renin angiotensin aldosterone system
MED	hypertensive vascular disease produced by homologous renin administration of rat renin to uninephrectomized rats reproduced most if not all the changes hypertension vascular disease hypertrophy of the zona glomerulosa of the adrenals found after partial constriction of the renal artery this is taken as evidence that the renal pressor system plays a major role in the pathogenesis of renal hypertension
MED	effects of hypophysectomy and growth hormone on renal compensatory hypertrophy in rats the effect of hypophysectomy on renal compensatory hypertrophy rch was observed in unilaterally nephrectomized rats receiving no therapy and those receiving replacement therapy and was compared to the rch attained by non hypophysectomized unilaterally nephrectomized rats at 2 5 and 10 days in the latter group there was an initial rapid rch seen at day 2 which continued but at a slower rate through day 10 in the hypophysectomized group without replacement therapy there was also an initial rch in the first 48 hrs however instead of the rch continuing there was a regression in kidney size at 5 days and with no subsequent change at 10 days in the hypophysectomized group receiving hormone replacement there was an initial rch comparable to the other 2 groups but the further renal enlargement at 10 days was much less than that of the non hypophysectomized animals the results of this experiment and of other reported studies imply existence of a renotropic factor which is not produced in the pituitary but which requires an intact pituitary for full effectiveness
MED	extrarenal fibromuscular hyperplasia clinical radiologic and pathologic studies on 19 patients with lesions in the extrarenal arteries that resembled fibromuscular hyperplasia are described in 11 patients fibromuscular hyperplasia was present in the renal arteries patients with involvement of the celiac artery were the only ones who had symptoms of visceral ischemia fibromuscular hyperplasia of the internal carotid arteries was observed in 6 patients 2 of whom had symptoms of cerebral ischemia nine patients with fibromuscular hyperplasia of the carotid or renal arteries had intracranial aneurysms and in 2 others intracranial hemorrhage developed in the absence of demonstrable aneurysms the histologic similarities between intracranial aneurysms and other types of aneurysms that appear in patients with fibromuscular hyperplasia the frequency of intracranial aneurysms in patients with extracranial fibromuscular hyperplasia and the similar sex and age incidence suggest a common etiologic origin
MED	some speculations on the nature and significance of developmentally small kidneys renal hypoplasia renal hypoplasia may take several forms among these the best known is perhaps renal dysplasia in which the parenchyma is maldeveloped other forms of hypoplasia in which the renal parenchyma is normally formed but merely diminished in amount do exist and may have severe clinical consequences the finding at postmortem examination of anatomically small kidneys in children who suffered excessive or unexplained dehydration has prompted the thought that renal tubular insufficiency may result from renal hypoplasia
MED	a study of induced renal hyperplasia using autoradiography to establish a base line for future autoradiographic investigations compensatory renal hyperplasia was studied using tritiated thymidine labelled cells were infrequent in the tubular tissues of control kidneys in the kidneys remaining after unilateral nephrectomy there was a 5  to 6 fold increase in the cortex and a 12  to 13 fold increase in the medulla of labelled tubular cells over the numbers seen in control tissues the findings obtained here are in agreement with the observations made in earlier investigations with routine methods of staining and mitotic observation
MED	compensatory structural and functional changes in the kidney the radiographic assessment of the renal size and the factors influencing renal hypertrophy are discussed the importance of compensatory hypertrophy and its prognostic significance is emphasised the changes are correlated with renal function as measured by the glomerular filtration rate and renal plasma flow
MED	bilateral renal hypoplasia of the pig bilateral renal hypoplasia of the pig is described and is compared with a previous description the defect was observed in 19 piglets out of a total of 73 born in 8 litters sired by one large white boar twelve affected piglets died at or soon after birth and 7 died between the ages of 11 and 69 days inheritance by a simple autosomal recessive factor is suggested by the evidence grossly the condition was characterized by varying degrees of hypoplasia and persistence of fetal lobulation microscopically the dominant feature was the poor development of the collecting tubule system it is concluded that the basic defect is a failure of development of mesonephric mesenchyme
MED	the effect of nortestosterone phenylpropionate on compensatory hypertrophy of the remaining kidney after unilateral nephrectomy forty eight hr after unilateral nephrectomy both in non castrated and in castrated male mice the relative dry weight of the remaining kidney increased significantly this compensatory hypertrophy was significantly stimulated as early as 96 hr after operation by treatment with 19 nortestosterone phenylpropionate npp at the time of operation the percentual increase of the kidney weight was approximately the same in non castrated as in castrated mice the absolute initial values as well as the resulting values 96 hr after operation were higher in non castrated male mice than in castrated animals the number of cells and the dna concentration per g tissue decreased during the period of non stimulated compensatory hypertrophy in both groups of animals npp caused a still further decrease the concentration of dna per cell did not change following non stimulated compensatory hypertrophy there was no change in the rna concentration per g tissue or per cell in castrated mice in non castrated mice the concentration increased npp caused approximately the same percentual increase of rna concentration in non castrated as in castrated animals during the period of compensatory hypertrophy the difference between both groups of mice in the rna concentration in the remaining kidney following stimulation of the compensatory hypertrophy by npp was statistically significant
MED	thyroid and pituitary gland activity during compensatory renal hypertrophy autoradiographic studies with tritiated thymidine showed an increased synthesis of dna and cellular proliferation of the thyroid and pituitary during compensatory renal hypertrophy
MED	the influence of thyroid hormone on renal function during the course of compensatory hypertrophy during the course of compensatory hypertrophy of the kidney glomerular filtration and renal plasma flow increased to a less extent in thyroidectomized animals than in control animals the secretory capacity of the renal tubules of thyroidectomized animals increased insignificantly during compensatory hypertrophy but increased markedly after administration of thyroid hormone
MED	kidney cell proliferation after unilateral nephrectomy as related to age the effect of unilateral nephrectomy on the number of cortical kidney cells undergoing dna synthesis and mitosis was measured by tritiated thymidine autoradiography in both weanling and adult rats among the unoperated control animals the weanling rat group showed a base line labeling index of 0 59 and the adult animals one of 0 11 the response to unilateral nephrectomy resulted in a peak value of 3 6 in the weanling animals and 1 2 in the adult animals both occurring at 36 hr mitotic indices were 0 056 in the weanling control animals and 0 0062 in the adults with a peak of 0 30 and 0 088 resp at 36 hr separate counts of tubule and stromal cells in the cortex revealed that the maximum increase in labeled cells occurred later in the stromal cells than in the tubule cells the stromal cells not reaching a maximum until 57 hr after nephrectomy the findings indicate that although the relative proliferative activity is much lower in adult animals a similar response qualitatively is obtained in both groups after unilateral nephrectomy
MED	influence of the adrenal glands on dna synthesis in normal and compensating kidneys the role of the adrenal glands in controlling the synthesis of dna in normal and compensating kidneys of rats given saline drinking fluid was studied using tritiated thymidine and radioautography adrenalectomy alone increased significantly the labeling of the renal cortex and medulla of otherwise intact rats two days following unilateral nephrectomy of rats with intact adrenal glands the number of labeled nuclei in the remaining kidney increased by factors of about 4 and 2 5 in the cortex and the medulla respectively adrenalectomy moderately decreased the hyper plastic response of the cortex of the remaining kidney but increased still further the labeling index of the medulla by 5 days after unilateral nephrectomy of rats with intact adrenal glands neither the cortex nor the medulla of the remaining kidney exhibited a marked hyperplastic response in adrenalectomized animals also unilateral nephrectomy caused only slight increases in the labeling indices of the cortex and the medulla of the remaining kidney
MED	auto radiographic studies of the protein metabolism of the single kidney in the nephrectomized rat rats were subjected to unilateral nephrectomy following which the protein metabolism of the other kidney which exerted a compensatory activity was studied with h labelled l phenylalanine at different intervals 3hr to 7 wk two phases of enhanced incorporation of amino acids into the cells of the convoluted tubules were found with one maximum after 6 hr at which time the uptake is limited to the cytoplasm and a 2nd maximum on the 4th day when the nucleus is equally involved in the course of the 2nd phase of enhanced amino acid uptake there is also an increased mitotic index of the epithelia of the tubules in the collecting tubules there was only one phase of enhanced amino acid uptake with a maximum on the 4th day also coinciding with an increased mitotic index the increase of the number of cells of the kidney was determined by a study of the variations of the mitotic index the mean multiplication factor in the beginning amounts to 1 6 the protein metabolism is increased 1 3 times the increase of the volume factor 1 3 and the increase of the protein metabolism per unit of volume factor 1 3 of the hypertrophic kidney result in a total increase of the protein metabolism of 2 1 times once the adaptation process is complete so that the residual kidney has approximately the same protein metabolism as 2 normal kidneys
MED	two brothers with nephrogenic diabetes insipidus the patients a 5 year old and a 13 year old boy had suffered from polydypsia and polyuria since the age of 1 yr physical and mental retardation hyperchloremia and lowering of kidney concentrating power were observed the patients were resistant to pitressin they were considered to be suffering from nephrogenic diabetes insipidus caused by a recessive heredity factor
MED	studies on the sweat in renal diabetes insipidus during treatment with saluretics description of a 5 month old boy suffering from familial diabetes insipidus his sweat as well as that of his mother had an increased nacl content chlorthalidone and fursemide had a different effect both on the quantity and on the nacl content of the sweat a single dose of chlorthalidone decreased the nacl content for a short time but increased the quantity of sweat during 3 days fursemide given intermittently produced a decrease of the sweat nacl also during the intervals and an increase of the quantity of sweat however as a contraregulation during the intervals the quantity of sweat decreased and at the same time the urea content increased from the isotonic serum filtrate in the sweat glands ho and nacl were reabsorbed in the ducts and the urea concentration increased but the reabsorption of ho and nacl did not go parallel therefore the sweat is hypotonic this regulation is altered in diabetes insipidus therefore the high values of nacl without changing the osmolarity na is exchanged with k this mechanism is accentuated if the na concentration is high
MED	diabetes insipidus treated with synthetic lysine vasopressin a case of diabetes insipidus was associated with an eosinophilic granuloma in a 2 5 year old child partial control of symptoms was achieved with pitressin tannate in oil 7 5 u i m on alternate days synthetic lysine vasopressin i m controlled the urine output at a dose of 5 u 8 hourly but the preparation was not well tolerated it was therefore given by the nasal route and over a 6 month period the diabetes was controlled with a dose of 14 u t d s
MED	the action of vasopressin in renal diabetes insipidus as the water retaining action of antidiuretic hormone is eliminated in renal diabetes insipidus the steps in na transport can be separately determined vasopressin induced a prompt increase in freewater clearance and urinary volume as well as a delayed increase in sodium clearance it is suggested that vasopressin brings about stimulation of sodium reabsorption in the ascending limb of henles loop it is supposed that both physiological actions of antidiuretic hormone   the antidiuretic and the sodium active effect   become operative in two different places in the nephron and synergistically produce a maximum concentration of urine
MED	pituitary diabetes insipidus associated with progressive urinary tract dilatation a case of pituitary diabetes insipidus with associated obstructive urinary tract changes is described the patient was treated both by surgical correction of lower tract obstruction as well as by control of the diabetes reversal of anatomic changes over a 1 year followup period is demonstrated
MED	the antidiuretic effect of angiotensin in diabetes insipidus the effect of angiotensin val 5 hypertensinii asp   amide was studied in 2 children with diabetes insipidus a 9 yr old boy with diabetes insipidus neuro hormonalis and a 4 yr old girl with diabetes insipidus renalis in whom the clearances of inulin pah na and urea and the osmolar and free water clearances were examined angiotensin produces a prompt antidiuresis which is combined with a gross decrease of the na clearance the osmolality of the urine is increased only slightly and the free water clearance does not become negative both effects being contrary to those seen with vasopressin the antidiuresis and antinatriuresis can be produced in salt loaded and salt deprived states furosemide reverses the effects of angiotensin the clearance of urea is not changed by angiotensin as long as the glomerular filtration rate remains normal
MED	polyuria in children twelve polyuric children have been investigated in the present report from their etiologico clinical aspect and they have been classified into four broad groups the first group of diabetes insipidus syndrome included 4 cases   3 of idiopathic type and one of the acquired variety due to hand schuller christian disease the 4 cases in the second group of nephrogenic diabetes insipidus after further investigations were diagnosed as renal acidosis 1 case other renal tubular syndromes with multiple defects 2 cases and hypokalaemic nephropathy 1 case the third group of polyuria due to chronic renal failure has been exemplified by one case the fourth group of 3 cases had compulsive water drinking as the probable etiology in addition to the illustrative case histories a practical diagnostic approach in the context of physiopathology of normal urine excretion has been recommended
MED	treatment of diabetes insipidus synthetic lysine vasopressin nasal solution twenty patients with vasopressin deficient diabetes insipidus were treated with a nasal solution of synthetic lysine vasopressin use of the nasal spray 2 to 8 times daily controlled polyuria in all patients without recurrence of the side effects occasionally observed with posterior pituitary preparations of animal origin one pregnant patient was well controlled to term without undesirable uterine stimulation because of its ease of administration the absence of significant water retention if used judiciously and the freedom from potentially serious allergic reactions to foreign protein this synthetic preparation is recommended for clinical use
MED	synthetic lysine vasopressin nasal spray in the treatment of diabetes insipidus thirteen patients with diabetes insipidus were satisfactorily and conveniently treated with synthetic lysine vasopressin nasal spray the material being administered 3 to 5 times per day in a total daily dosage ranging from 35 to 125 u a transient decrease in effectiveness was noted during periods of upper respiratory infection or allergic rhinitis the only adverse effects of the nasal spray consisted of minor nasal irritation in 3 patients and increased frequency of bowel movements in one child after he increased the dose in an effort to concentrate and restrict urine volume in hydrated normal subjects lysine vasopressin administered s c is 7 4 times as effective as the nasal spray preparation
MED	diabetes insipidus treatment with 8 lysine vasopressin in a nasal spray synthetic 8 lysine vasopressin administered as a nasal spray to 3 patients with diabetes insipidus resulted in excellent control in one in the other 2 it was of some value as therapy supplemental to pitressin tannate in oil the patient who was adequately controlled with spray therapy alone required the sprays every 3 hr during the day but none during the night
MED	salt and water distribution in hereditary and in induced hypothalamic diabetes insipidus in the rat salt and water metabolism and the distribution of na k and water in gastrocnemius and in aorta were measured in spontaneous hereditary hypothalamic and in surgically induced diabetes insipidus in the rat the degree of severity in the 2 types of the disease was estimated in terms of salt and water handling water turnover in 24 hr was about equal to body weight in the hereditary disease and about 60 of body weight in the induced disease skeletal muscle na increased more than 20 in the familial disease and the gain involved both cells and environment there was no corresponding loss of k similar changes of lesser degree were noted in the induced disease the degree of na accumulation appears to be partially dependent on the duration of the disease
MED	antidiuresis induced by saluretics in diabetes insipidus in hypothalamus pituitary and less regularly in nephrogenic diabetes insipidus some diuretics cause a fall in diuresis mainly due to reduced excretion of free water this adh like action not correlated with the extent of the natriuretic action or with salt depletion depends on a direct effect of the drug on water permeability in the distal tubule and is suppressed by cortisone it is maximal for the thiazide derivatives and diminishes progressively with mercurial compounds spirolactones and triamterene in that order and is absent for acetazolamide the reduction in glomerular filtration and increased proximal reabsorption of na following salt depletion induced by the diuretics is of less importance and irregular in appearance
MED	congenital hydronephrosis histological study of the renal parenchyma in cases of hydronephrosis is a guide for surgical treatment if the renal parenchyma is reduced in thickness to 3 mm or less it leads to complete atrophy but if the thickness is more than 3 mm conservative procedures are justified
MED	neurohypophysial principles in rats with familial hypothalamic diabetes insipidus brattleboro strain antidiuretic and oxytocic assays were performed on tissues from 3 female rats with familial hypothalamic diabetes insipidus di and on 3 normal females oxytocic activity was only slightly lower in the pituitaries from the di rats antidiuretic activity in the pituitaries from 2 di rats was no more than that expected from their content of oxytocin thus these pituitaries appeared to contain oxytocin but not arginine vasopressin the hypothalami from these 2 rats showed minimal antidiuretic activity which might have been due to oxytocin or vasopressin the pituitary from the third di rat contained more antidiuretic activity than could be due to oxytocin antidiuretic responses to extracts of pituitary and hypothalamus from this rat resembled those produced by arginine vasopressin this pituitary appeared to contain about 1 100 the normal amount of vasopressin since vasopressin can inhibit diuresis in these di rats it would appear that they have a specific deficiency of endogenous arginine vasopressin
MED	familial renal diabetes insipidus renal diabetes insipidus has been known for 20 yr only the first german report on such a case appeared in 1957 nevertheless this disease appears to be more frequent also in germany a report is given on 4 infants from 2 families with a verified diagnosis in the one family there were 3 other cases with the features of the disease polydipsia polyuria low sg of the urine in the other family anamnestic studies revealed 5 such cases
MED	evaluation of 20 years experience with the treatment of hydrocephalus in infants a total of 394 infants were examined between 1943 and 1962 till 1961 369 infants were examined and 246 were operated on 66 7 this group is analyzed laurences opinion on the favorable spontaneous evolution is not agreed to and the merits of surgical treatment are proved a dynamic form of hydrocephalus in operated infants is shown the patients who were not operated on suffered from other diseases combined with macrocephaly which must be distinguished from hydrocephalus a spontaneous arrest of the process was observed in only 14 children e g 3 8 as compared with laurences 42 6 the cause and pathological findings are analyzed in 102 infants operated on between 1957 and 1962 a great discrepancy between the time of the onset of first symptoms and the time of operation was found this disease manifests itself in 50 of infants in the first month of life but the average age of infants at the time of operation is 6 1 mth only 3 of infants are operated on in the first month thirteen operating procedures were used in the 20 yr under review until the introduction of deviation of the csf into the jugular vein or into the cardiac atrium 15 33 of the infants survived 1 yr after operation since the introduction of this procedure the survival rate of infants was 67 8 in spite of the late operation about 27 of surviving children showed an average mental development surgical treatment of dynamic hydrocephalus is advocated they consider this method as the only means of helping the infant at present
MED	cerebrospinal fluid dynamics in the arnold chiari malformation a method using radio iodinated serum albumin to measure the volume of the ventricular system and the rate of disappearance of csf from the lateral ventricles has been described newborn infants with a rate of flow less than 70 ml 24 hr after surgical repair of the myclomeningocele will develop progressive hydrocephalus requiring a ventriculo atrial shunt the test can be used to detect the patency of a ventriculo atrial shunt and may allow safe removal of the shunt in selected patients
MED	coexistent cranial and spinal defects with hydrocephalus in five infants the etiology and significance of craniolacunia in these defects the clinical roentgenographic and etiologic factors in 5 infants with varying cranial defects craniolacunia and craniofenestra or cranial meningocele hydrocephalus and spinal defects meningocele or myelomeningocele are described all of the infants expired of bacterial complications the etiologic factors and significance of cranial defects in these coexistent malformations of the central nervous system are reviewed
MED	hydrocephalus and myelomeningocele central nervous system infection a series of 38 incidents of cns infection in 34 patients with hydrocephalus myelomeningocele or both have been summarized gram positive organisms occurred more frequently and caused infections resulting in a mortality of 33 the gram negative organism induced infections resulted in a mortality of 60 nearly 50 of the infections occurred in patients before any shunting procedure was done the staphylococcus caused two thirds of the infections in patients with a shunt in situ no obvious portal of entry could be demonstrated in a majority of patients of 5 patients who received nonspecific prophylactic therapy because of an oozing myelomeningocele 4 survived of the 5 given no prophylactic therapy one survived a combination of kanamycin sodium methicillin and chloramphenicol appeared in vitro to be effective against most of the gram positive cocci the combination of chloramphenicol kanamycin and polymixin b appeared in vitro to be an effective combination against most of the gram negative bacilli
MED	myelomeningocele and hydrocephalus the first year of 50 patients fifty infants with hydrocephalus and myelomeningocele were treated comprehensively by a team of specialists patients were evaluated at death or the first birthday whichever occurred first twenty patients died 13 from bacterial infection thirteen of the survivors were classified as noncompetitive that is were thought to have a poor prognosis based on a developmental quotient of less than 80 seventeen patients were judged competitive in each case the latest developmental quotient was more than 79 and the urinary tract was not irreversibly decompensated developmental quotient was based on motor development adaptive behavior language development and personal social development this report is a progress report in a longitudinal study in comparison with a previously surveyed group the results seem encouraging current data from 39 older patients followed 6 to 13 yr show 2 competitive survivors 11 noncompetitive survivors and 26 deaths
MED	pneumoencephalographic changes in the cavum septi pellucidi and their clinical significance the pneumoencephalographic appearances and clinical problems associated with communicating and non communicating cavum septi pellucidi are discussed on the basis of 11 cases non communicating csp may lead to intermittent headaches due to variations of intracranial pressure and obstruction to the flow of csf in rare cases representing a special etiological group the foramina of monro and the aqueduct may be narrowed a communicating csp is generally associated with mild to moderate symmetrical internal hydrocephalus in the authors opinion this is in most cases a direct result of the cavum since fluid continues to be formed in the cavum after communication with the rest of the ventricular system has been established the conditions resemble those in hypersecretory hydrocephalus for these reasons the author rejects the view that a communicating csp is of no clinical significance in some cases the possibility of a combination of a cavum with a cerebral malformation must be considered
MED	posterior scalloping of vertebral bodies in uncontrolled hydrocephalus two cases of extensive posterior scalloping of the vertebral bodies are presented in men aged 17 and 23 years having long standing hydrocephalus two additional cases with scalloping of only one lumbar vertebra when partially controlled hydrocephalus has been present for a shorter time are also noted no previous association between these entities has been recorded it is supposed that the increased intraspinal pressure which must have been present in the first 2 patients for many years was present near the time of closure of the epiphysis at the junction of the arch and the bodies and caused not only widening of the spinal canal but also excavation of the vertebral bodies scalloping of vertebral bodies has been described in 1 neoplasms neurofibromas meningiomas gliomas hemangio endotheliomas hemangiomas lipomas 2 intraspinal cysts intradural arachnoid cysts tarlovs perineural cysts thoracic extradural cysts in kyphosis dorsalis juvenilis 3 congenital anomalies of the spine and cord fusion defects myelodysplasia hydromyelia absence of a single vertebral pedicle meningoceles and 4 neurofibromatosis with or without a thoracic meningocele
MED	electroencephalographic picture of the infantile hydrocephalus in 50 of 33 cases of congenital hydrocephalus the eeg examinations were normal asymmetry of the eeg recording was the most common abnormality encountered both in congenital and in acquired hydrocephalus none of the children examined revealed any focal neurological symptoms it is concluded that eeg examinations could be useful in differentiating congenital from acquired hydrocephalus because a normal eeg recording suggested the congenital nature of the condition
MED	consecutive hydrocephalus report of 2 cases two patients each with 3 consecutive hydrocephalic newborns are reported consanguinity was present in both families a genetic basis for the hydrocephalus is suggested
MED	fanconis anaemia with hydrocephalus and thyroid abnormality a case is described in a girl who suffered from dwarfism due to congenital hypoplasia of the pituitary and from other congenital malformations the pancytopenia manifested itself at the age of 2 yr and was resistant to a combined corticosteroid testosterone treatment unusual findings in this case were congenital hydrocephalus hypoplastic spleen and hypoplasia of thyroid together with persistently high pbi serum levels but without apparent changes in thyroid function
MED	dandy walker taggart syndrome a case report dandy walker taggart syndrome in a 6 month old girl has been substantiated by a correlation of clinical and pathological features all 3 exit foramina of the 4th ventricle have failed to open resulting in severe cystic dilatation of the ventricle and hypoplastic distortion of posterior midline cerebellar structures
MED	hydrocephalus due to smallpox occurring in the fetal period out of 450 cases of hydrocephalus in the years 1959 1962 15 were found whose mothers had contracted variola after the 3rd month of pregnancy based on these personal cases and the sparse data in the literature the clinical epidemiological radiographical skull biological and histopathological aspects are presented 2 fatal cases were histopathologically examined it could be demonstrated that the hydrocephalus occurred as a manifestation of a disease involving the fetus and was caused by a variola infection during gestation inferences are given from the eeg and examination of the liquor
MED	air pantopaque ventriculography in congenital hydrocephalus and myelomeningocele a study of the csf pathways by combined pantopaque air ventriculography in infants with congenital hydrocephalus and myelomeningocele is presented the advantages of this method are discussed combined pantopaque and air ventriculography provides not only a demonstration of the extent of the hydrocephalus but also the exact location and cause of the obstruction in infants with myelomeningocele it permits the disclosure of unmanifested hydrocephalus and coexistent intracranial malformations the early detection of the latter is very important for the complete evaluation management and prognosis the introduction of pantopaque into the ventricular system of infants did not produce an immediate reaction and did not precipitate deterioration of the clinical status retention of small amounts of pantopaque in the lateral ventricles did not interfere with the function of bypassing procedures
MED	two cases of dandy walkers syndrome dandy walkers syndrome refers to a particular kind of malformative hydrocephaly characterized anatomically by association with a more or less considerable agenesis of the cerebellar vermis and with an imperfection of the foramina of luschka and magendie the dysgenetic nature of this picture is obvious but the pathogenesis of the hydrocephaly is not simple and the etiology remains obscure the malformation is compensated more or less quickly in the life of the subject the clinical picture is that of a hydrocephaly by a tumor of the posterior fossa the diagnosis can and must be carried out by x ray examination the ventriculographic images being pathognomonic the extreme ease of surgical restoration of the passage of flow and the effectiveness of timely operation emphasize the interest of this syndrome which turns out to be a rare kind of curable malformative hydrocephaly the authors report 2 unpublished cases in respect of 3 yr  old children the first already going back several years 1945 had unfavorable postoperational results the second 1962 recovered completely without sequelae after resection of the posterior wall of the cyst
MED	incidence and treatment of post meningitic hydrocephalus in the newborn the incidence of meningitis in the first few weeks of life is higher than in any comparable period of life even if cases associated with spina bifida cystica are excluded the gravity of the prognosis even since the introduction of many powerful antibiotic drugs has been frequently emphasized among the 7 cases which occurred in a maternity unit 5 eventually made a complete recovery in a group of 19 infants who developed postmeningitic hydrocephalus and were referred either with still active meningitis or the postmeningitic state only 1 infant could not be treated by a ventriculocaval shunt this infant and 4 others died later of the 14 survivors 7 recovered without sequelae in spite of extreme hydrocephalus which was demonstrated by air studies before operation the degree of hydrocephalus no matter how severe is no contraindication to operation
MED	comparative values of thick drop and concentration methods detection of filaria infection blood was drawn from the finger and vein in 246 students from 11 p m to 2 a m to compare the diagnostic efficacy of thick drop method vis a vis concentration method infection rate was found to be the same 2 5 by both methods and 5 students harbouring infection were found to be positive by both methods infestation rate in the concentration method was higher being 14 per slide against 4 per slide in the thick drop method
MED	filariasis in its relation to a a bo mn kell duffy and rhesus blood groups and secretor factor 603 filariasis patients have been studied for a a bo blood groups 281 for duffy kell and rhesus blood groups 178 for secretor factor and 503 for mn blood groups to find out if there is any association between filariasis and these blood groups no association whatsoever has been found between the blood groups studied and filariasis
MED	a polyethylene tube culture method for the diagnosis of parasitic infections by hookworms and related nematodes studies were made in amami island and in bangkok to compare the diagnostic efficiency of direct microscopical examination test tube culture and the newly devised polyethylene tube culture method for the detection of filariform larvae the results show that the new technique has a number of advantages over the other methods it is more sensitive than the others for the detection of cases of slight infection and greatly reduces the risk of overlooking small numbers of larvae polyethylene tubes are extremely cheap compact and light and can be very easily disposed of after use
MED	some observations on the effects in vivo of varying ambient temperatures on filarial worms of snakes new information was obtained on the biology of filarial worms from experiments using constrictor constrictor mexicanus boas infected with macdonaldius oschei worms the microfilariae of m oschei are aperiodic with respect to the light cycle but fluctuate sharply in density from day to day maximum minimum levels occur approx 2 days apart the microfilariae are larger and more variable in size on the days of maximum density than on the days of minimum density it is suggested that the smaller microfilariae on the days of low parasitemia are those that have been born recently and that they enlarge during the following 48 hr before they enter the peripheral capillaries low ambient temperatures have little effect upon m oschei exposure of the host to ambient temperatures above 36 c for a period of 24 48 hr appears sufficient to kill adult m oschei all microfilariae apparently die within 144 hr at this temperature and in slight infections they disappeared from the blood altogether within that period microfilariae from an infection 20 times more severe however were not eliminated from the circulation prior to the death of the host after 288 hr although all those observed were either decomposed or distorted and apparently dead the indication that the temperature serves as a limiting factor for the parasite at a point several degrees lower than that postulated for the host species is probably correlated with the nocturnal habits of the host
MED	preliminary report on the leucoconcentration technique applied to the study of microfilaraemia in a case of filariasis due to wuchereria bancrofti the routine leucoconcentration technique used in the demonstration of steinbergs neoplasic cells in circulating blood was applied this method makes it possible to obtain considerable enrichment demonstration of filaria can be performed during daylight from the material obtained preparation of specific antigens that make possible an immunological diagnosis may be carried out
MED	concentration techniques of sanguicolous microfilariae a technique is described for concentration of sanguicolous microfilariae a modified harris and summers method
MED	pathology of schistosoma japonicum in the taiwanese monkey macaca cyclopis i comparison of formosan and japanese strains ii effect of passing the formosan strain through japanese snails i nearly equal recovery rates of adult worms from taiwanese monkeys macaca cyclopis infected with formosan or japanese strains of sch japonicum were recorded worm recovery rates from the monkeys were low when comparison was made with the highly susceptible laboratory rabbit signifying only partial susceptibility formosan strain granulomas in the liver contained fewer eggs but were considerably more severe and extensive than japanese strain granulomas the possibility that the large atypical granulomas could be reactions to young degenerating formosan worms is discussed an alternative hypothesis to explain the dissimilar reactions that formosan strain eggs are stronger tissue irritants than those of the japanese strain is proposed ii the formosan strain of sch japonicum was passed through the japanese snail intermediate host oncomelania nosophora for 4 consecutive generations progressively rising rates of snail infection and mortality were recorded the resultant laboratory strain of formosan schistosome was used to infect taiwanese monkeys monkeys infected with the natural formosan strain and natural japanese strain served as controls worm recovery rates were similar in the 3 groups granulomatous responses in the liver produced by the laboratory strain were compared with the large atypical granulomas of the natural formosan strain and the conventional granulomas of the natural japanese strain the new formosan strain appeared altered toward characteristics possessed by the japanese strain
MED	a review of immunologic methods for the diagnosis of filariasis the author reviews the historical application of the skin test cft precipitin test haemagglutination and bentonite flocculation and prausnitz kuestner test to the diagnosis of various filarial infections in man and animals with a discussion of areas requiring further study he is of the opinion that with standardization of techniques immunologic methods can be made to furnish a reliable means of diagnosis notwithstanding the past unreliability of such methods a bibliography arranged in chronological order lists 125 papers covering the period from 1916 to 1962 and a supplementary list of references includes 22 recent papers on general aspects of the subject
MED	schultz dale reaction with sera of eosinophilic lung patients   a preliminary report schultz dale tests have indicated that specific antibodies to metabolite products of microfilariae are present in the serum of an e l patient and that diethylcarbamazine in concentrations of 1 2000   1 1000 were required to cause perceptible cessation of contraction in intestinal strips used sufficient tests have not yet been completed to indicate a consistent relationship between any particular filarial species and eosinophilic lung disease
MED	an evaluation of the bentonite flocculation and indirect hemagglutination tests for the diagnosis of filariasis the indirect haemagglutination test and the bentonite flocculation test utilizing a saline extract of dirofilaria immitis have been evaluated the test was reactive with sera from individuals with infections of acanthocheilonema perstans and showed higher titres for symptomatic patients with microfilariae in the blood in a group of 42 symptomatic patients 92 of 13 microfilariae positive patients and 62 of 29 microfilariae negative patients showed positive serologic tests in a group of 15 asymptomatic individuals with microfilariae in the blood 67 were positive from a group of 295 asymptomatic microfilariae negative individuals 21 sera 7 were positive testing 632 sera from 295 normal missionaries 84 normal americans and 253 individuals with various other parasitic and bacterial infections an overall non specific response of 10 was obtained utilizing the following criteria for a positive serologic test 1 haemagglutination titre of 1 200 or higher with a positive flocculation of 1 5 or higher or 2 a haemagglutination titre of 1 400 with a negative flocculation reaction sera from 141 patients with helminth diseases showed a non specific rate of 21 this high rate was due to cross reactions with trichinosis sera 35 schistosomiasis 20 and ascariasis 27 since the schistosomiasis and ascariasis sera were from individuals born in an area endemic for filariasis the reactions may represent a serologic response to past experience with filariasis only 5 of 112 sera from individuals with non helminthic diseases and 5 of 84 sera from normal individuals were positive
MED	filariasis in mountain province luzon republic of the philippines an endemic focus of w bancrofti in mountain province luzon calaccad valley is discussed an 11 microfilaremia rate was found the parasites were probably brought into this area in the original human migration as recent immigrants came from non infected areas no infection was found in children under 12 yr of age which correlates with spraying of the area since 1953 however some people live in unsprayed houses and children may become infected with coming road development and urbanization culex p fatigans will move in and undoubtedly increase transmission currently anopheles minimus flavirostris is the most important local vector aedes finlaya niveus was probably also a vector
MED	immunological studies on filariasis iii isolation and purification of antigen for intradermal skin tests an antigen for intradermal skin tests was extracted from the homogenate of dirofilaria immitis with a phosphate buffer at ph 7 2 and purified by sephadex g 100 gel filtration cm cellulose chromatography and deae sephadex a 50 column chromatography the finally purified antigen fscd1 was a protein with a small amount of carbohydrate 2 5 and gave a relatively broad band by electrophoresis on cellogel film the aminoacids detected by high voltage paper electrophoresis of the acid hydrolyzate of the antigen were lysine arginine glycine alanine glutamic and aspartic acids and valine wheals and an erythema appeared within 15 min of the injection of the antigen 0 05 on proved filariasis patients cross reactions were examined in patients with p westermani s japonicum hookworm a lubricoides or e vermicularis but only weak skin reactions were noticed in all cases the protein nature of the antigen was further proved by the fact that proteolytic enzymes destroyed the antigenic activity to a considerable extent
MED	human filariasis identification of species on the basis of staining and other morphologic characteristics of microfilariae new staining procedures for human microfilariae are described the morphologic details characteristic of each species are illustrated with apparent greater clarity than previously obtainable a simple key to the human microfilariae is outlined based on criteria clearly demonstrated with these stains
MED	immunological studies on filariasis iii fractionation and purification of antigen for intradermal skin reaction in filariasis it had been reported that the antigen tca obtained from adult worms of dirofilaria immitis produced noticeable reactions in filariasis patients in whose blood microfilariae could be demonstrated further fractionation and purification of this antigen was attempted in order to study the substance responsible for the skin reaction and to obtain a more reliable antigen with high sensitivity and specificity the fraction fs obtained by treatment similar to that described in the previous report was used as parent material by gel filtration and sephadex g 100 column chromatography of antigen fs antigen fsi which produced noticeable reactions in the filariasis patients was obtained this highly reactive antigen fsi was separated into 6 fractions viz fsc 1 fsc 2 fsc 3 fsc 4 fsc 5 and fsc 6 by cm cellulose chromatography the 6 antigens were tested at the 1 protein component level on patients infected with wuchereria bancrofti antigen fsc 4 containing 1 500 of protein and 40 of carbohydrate per ml was most active next the further fractionation of antigen fsc 4 by deae sephadex a50 column chromatography was carried out to yield 4 antigens viz fscd 1 fscd 2 fscd 3 and fscd 4 the 4 antigens were tested at the 0 05 protein component level on filariasis patients antigen fscd 1 produced the most noticeable skin reaction in the patients the elimination of protein components from antigen fscd 1 was attempted with nagase a proteolytic enzyme and pronase to obtain antigens fscdn and fscdp each of these 2 antigens was tested on the patients proved to have filariasis but the reaction produced by the injection of each antigen was weaker than that produced by antigen fscd 1 it may be inferred from these studies that the substance responsible for the skin reaction is proteinic
MED	identification of canine microfilariae the importance of microfilarial identifications in diagnosing canine filariasis was emphasized by comparing the significance of infections due to different species personal experiences and an analysis of published reports found the modified knott method to be the simplest and most practical of the reliable methods its usefulness was improved by new morphologic criteria for differentiating microfilariae microfilarial concentrations in peripheral blood from a number of naturally infected dogs were determined the average count for 44 dogs infected with dirofilaria immitis was only 24 430 range 50 to 168 350 per ml of blood compared with an average of 235 range 50 to 2 450 per ml for 100 dogs infected with dipetalonema reconditum only of 38 dogs with inapparent infections of d immitis 17 had microfilarial concentrations within the range found for infections of d reconditum only male and female dogs with d reconditum had similar concentrations of microfilariae
MED	chemotherapy of metastatic gastro intestinal cancer cancer of the digestive tract is the commonest cause of death from neoplastic disease in the united states a large number of patients with these forms of incurable cancer may be candidates for specific anti tumor drug therapy the criteria employed for the selection of patients for systemic or regional chemotherapy are reviewed and methods of treatment are outlined systemic chemotherapy using fluorinated pyrimidines the antifol methotrexate and the alkylating agent cytoxan has been found to be of significant practical value in 10 to 30 of the patients receiving these anticancer drugs protracted hepatic artery infusion chemotherapy in patients with primary and secondary hepatic neoplasms and tumors of the biliary system has resulted in objective tumor response and associated clinical benefit in 60 of the patients treated length of survival has been prolonged in patients with advanced metastatic liver cancer from primary tumors of the colorectum it is concluded that systemic and regional cancer chemotherapy in selected cases has contributed to the practical management of patients with incurable cancer of the gastrointestinal tract
MED	palliative treatment of osseous metastases from carcinoma of the breast and carcinoma of the prostate with radio active phosphorus and testosterone fifty three patients suffering from pain arising in bony metastases from carcinoma of the breast and prostate are discussed a method of palliative treatment is outlined and the results reported
MED	regional chemotherapy by prolonged arterial infusions in head and neck tumors methotrexate was injected into the superficial temporal or superior thyroid artery by perfusion 100 mg 1 20drops min every day for 8 days the area to be irrigated was decided on by preliminary perfusion of patent blue violet 11 results in 54 inoperable patients were deaths 7 failures 19 improvements 28 total regressions 3 pain was relieved in 3 4 of the patients
MED	intra arterial infusion emphasizing treatment of malignant neoplasms this review of the english medical literature summarizes most of the significant papers concerned with intra arterial infusion this technique of cancer therapy is effective for palliation of many advanced primary and recurrent cancer patients head and neck cancer patients form the largest group of patients that have been treated because of the easily accessible arteries however almost any involved organ can be infused by external approaches to the femoral brachial and common carotids most oncolytic chemotherapeutic agents can be given via the intra arterial route at notably increased dosages with the exception of 5fudr partial and complete regression of many tumors can be obtained with present day chemotherapeutic agents for 1 or 2 mth the best therapeutic results have been in patients with head and neck and pelvic tumors currently infusion techniques using small mobile pumping units permit the patient to be ambulatory during course of anti tumor therapy complications from intra arterial infusion are usually minor but serious complications do occur such as embolic phenomena to the cns with internal carotid infusion aplastic bone marrow from drug toxicity hemorrhage from tumor degeneration technical complications of the infusion may not be life threatening but frequently prematurely terminate the therapy continued interest in this form of therapy appears inevitable
MED	prolonged intra arterial chemotherapeutic infusion in cancer therapy its indications and limits in this review article 48 references the principles of cancer treatment using continuous intra arterial chemotherapy are described selection of patients operative technique and complications are dealt with two cases are presented which have been infused with methotrexate 1050 and 1600 mg with partial or complete objective remission a woman of 72 with a carcinoma of the amygdaloid fossa and a man aged 27 with a reticulosarcoma of the rhinopharynx
MED	intra arterial chemotherapy for cancer metastatic to liver twenty two patients with cancer metastatic to the liver were treated by the intra arterial infusion of cancer chemotherapeutic agents the drugs were introduced directly into the hepatic artery in 10 patients and into the aorta to the level of the celiac axis in 12 patients no significant differences in results were observed in the 2 groups of the 10 patients who received cancer chemotherapy via the hepatic artery one remains alive 2 mth after treatment 3 died in the immediate posttreatment period 7 survived from 1 17 mths after treatment an average survival of 6 1 mth all 12 patients who were treated by the intra aortic administration of cancer chemotherapy have died 3 patients died in the immediate posttreatment period the survival time of the remaining 9 averaged 3 7 mth an objective significant shrinkage of the metastases in the liver was observed in 6 patients 3 treated by the intra hepatic artery route and 3 via the aorta this lasted from 1 10 mth subjective palliation was observed in 12 patients 5 treated by the intrahepatic artery route and 7 by the intra aortic route the major complication noted was leukopenia to a lesser degree hepatic failure in those patients with poor metabolic reserve and in those who had received chemotherapy irradiation or both in the immediate past the complications were severe the need for critical screening for the proper selection of patients as candidates for cancer chemotherapy is discussed
MED	cancer chemotherapy by continuous intra arterial infusion experience of the veterans administration surgical adjuvant cancer chemotherapy infusion study group two hundred fifty one patients with advanced cancer have been treated with 365 courses of intra arterial cancer chemotherapy this technique and its complications and results are analyzed and discussed objective response was obtained in 57 of the patients treated the best results were obtained in epidermoid carcinoma of the head and neck and the poorest in primary brain tumors and intra abdominal adenocarcinomas ten per cent of all patients receiving at least 1 course of therapy and available for evaluation obtained worthwhile palliation for 6 or more months ten patients have had satisfactory results for periods of 12 to 28 months it is concluded that arterial infusion chemotherapy may be of benefit in the palliation of patients in whom other more conventional methods have failed or are contraindicated the frequency of serious complications suggests that at present this form of therapy should be used only by individuals and groups with special interest and experience in chemotherapy much further study of this type of cancer treatment is needed and various areas of investigation are suggested
MED	treatment of cancer by bacterial toxins the initial experience with toxin therapy for sarcoma and melanoma is reported in 3 groups of patients toxins used as an adjunct to operation in potentially curable patients palliative treatment for metastatic tumor and toxin therapy supplemented by radiotherapy for localized symptomatic tumor masses the experience has not been encouraging in the first 2 groups in 6 of 8 patients in the 3rd group there was marked objective remission of tumor subsequent to irradiation further study is indicated in the use of radiotherapy following priming with bacterial toxin injections
MED	radiotherapy of malignant rectal and anal tumors methods and results in 271 cases the results are given of the treatment of 271 patients 9 cases of anal and 262 of rectal carcinoma with conventional deep therapy and ultrahigh kilovoltage irradiation the total 5 year survival rate was 14 with surgical treatment it is according to a survey of the literature made by reifferscheid 19 9 according to guleke 20 25 and according to ottenheimer 21 3 a total of 39 patients received irradiation after questionable radical surgery and 11 patients received palliative irradiation after palliative surgery in most of these cases an anus praeter was performed altogether 48 patients received palliative irradiation without surgery and 45 patients received irradiation because of recurrence after apparent radical surgery 11 patients received irradiation because of metastases after apparent radical surgery and 6 patients because of metastases after palliative surgery ultrahigh kilovoltage radiation treatment showed better results than conventional deep therapy irradiation with 1 200 1 600 r on the site before surgery in stage c cases gives higher 5 year survival rates according to dukes henschke stearns et al
MED	the management of advanced cancer patients with incurable cancer may receive substantial relief of disabling mental and physical symptoms by constant and continuous medical management while usually of limited value certain measures of both specific anticancer therapy and nonspecific supportive therapy may relieve the symptoms and sustain the patients morale general supportive measures of value and the various cancer chemotherapeutic compounds and techniques of administration of these drugs are reviewed from the standpoint of patient selection practical application to various forms of cancer and limitations of these agents in patients with advanced cancer
MED	evaluation of ileal conduit as a palliative procedure during the 6 5 yr period ending july 1963 107 ileal conduit operations were performed at the city of hope medical center in the treatment of carcinoma of the bladder and other pelvic organs the character and extent of the lesions are described in detail the details of the surgical procedure are discussed complications including pyelonephritis uremia enteric and urinary fistulas wound infections and thrombophlebitis were common twenty eight of the 107 patients died during the postoperative period fifty nine of the 79 surviving patients are known to have died mostly as a result of recurrent uncontrollable carcinoma the procedure was considered palliative in 39 patients in 12 of these patients the lesion was removed and the conduit established in one stage 2 patients died in only 1 of the surviving 10 patients was the tumor under control the average term of survival was 8 5 mth the procedure was carried out in 2 stages in 4 cases 2 patients died after the 2nd stage the 2 surviving patients lived 1 5 and 4 3 4 mth respectively an ileal conduit alone was established in 23 patients 8 of whom died after the operation the average time of survival was 4 5 mth 1 patient was alive after 11 mth it is concluded that an ileal conduit in conjunction with total cystectomy in 1 stage is indicated as a palliative procedure but only when severe intractable symptoms exist and only when patients are carefully selected the procedure is poorly tolerated in older persons
MED	cancer chemotherapy by continuous intra arterial infusion of methotrexate continuous intra arterial infusions of methotrexate were used in the treatment of 45 patients with malignant disease of the head and neck 16 patients with advanced cancer of pelvic organs and 7 with malignant lesions of the lower limb in 4 patients with epidermoid lesions of the head and neck there was complete regression of the local tumor thirty three other patients benefited from treatment for varying periods of time but the remaining 30 showed no response eight patients died during or immediately after treatment all had advanced cancers of the head and neck region the mean total dose of methotrexate given in the patients with no response was significantly less than in those with partial regression of the tumor this suggests that the greater the total dose of methotrexate tolerated the greater the chance of beneficial response the role of continuous intra arterial chemotherapy in the management of malignant disease is discussed
MED	management of advanced ovarian carcinoma the life graph is presented for the purpose of illustrating the results of treatment for patients with ovarian carcinoma who eventually died from their disease it includes all patients regardless of initial stage of disease histology of the tumor or therapy employed the series is a selected one because of the type of patient referred to the medical oncology service and it demonstrates that almost 2 3 of the patients died within 2 yr of diagnosis all patients received active aggressive anti tumor as well as supportive therapy although there was no formal protocol for patient management it might be possible employing a standardized therapeutic approach irradiation when indicated to the entire abdomen in the dose range of 3 500 rads followed by judicious use of currently available anticancer drugs when the disease recurs to produce a modest increase in the 2 year survival figures since most series show that approximately 75 of patients with ovarian carcinoma are in stage iii of iv when first diagnosed more attention might be directed to earlier diagnosis while it is an important field for investigation methods of facilitating early diagnosis are not apparent at the moment controlled trials of adjuvant therapy for stage i and ii disease in which approximately 40 of recurrences are seen should be expanded this might consist of instillation of radioactive or chemical agents into the abdominal cavity the use of systemic chemotherapy during or immediately after operation or infusion of drugs into the abdominal aorta for stages iii and iv controlled trials of drugs alone sequentially or in combination with or subsequent to irradiation seem indicated finally efforts to find more effective anticancer drugs must continue
MED	liver resections for embolic metastases from cancer of the colon and rectum two patients who underwent resections of the left lobe of the liver for embolic metastases from primary cancers of the colon and rectum are reported the internal anatomy of the liver as it relates to the technic and terminology of resections is reviewed cases of liver resection performed for embolic metastases from cancer of the colon and rectum found in an extensive review of medical literature are classified and the results are analyzed resection of either half of the liver hemihepatectomy for embolic metastasis from cancer of the colon or rectum so rarely cures the patient and carried such a high operative mortality rate that it is seldom if ever justifiable the lesser operations left lobectomy or right lobe metastasectomy often can be performed simultaneously with the primary operation and are occasionally followed by freedom from recurrence for periods of 5 yr or more they are justifiable if the metastasis is situated favorably in the liver for complete removal and if the primary lesion appears to be curable
MED	palliative treatment of nonresectable lung cancer by upper hemibody perfusion of chlorimine short acting alkylating agent experience with five cases a method is discussed for providing palliative treatment for patients with nonresectable lung cancer by means of administering a short acting alkylating agent to the upper half of the body while temporarily occluding the circulation to the lower half of the body with proper selection of patients and an awareness of the potential complications the procedure appears to be safe and effective
MED	congenital extrahepatic biliary atresia a successful operated case on ductus hepaticus obstruction the author briefly reviews the history and the anatomical manifestations and the genesis of congenital extrahepatic biliary atresia and its associations with other abnormalities he collected 957 cases in the literature from ladds first successful operated case up to the end of the year 1961 in publications he found 177 theoretically correctable cases and 124 which were recovered in 1 of 2 personal cases he performed successfully a hepatico duodenostomy in a 7 week old girl four years later the girl had developed normally and she was absolutely without symptoms and signs the author discussing the differential diagnostic problems stresses the diagnostic value of the gradually increasing direct serum bilirubin proposing the term ex juvantibus differentiation alluding to the differential diagnostic evaluation of the time which passes until the surgical exploration he also emphasizes the need of early latest up to the age of 8 weeks performed surgical exploration according to him the administration of vit k is advantageous he supposes the cause of the postoperative dehiscence of the operative wound lies in the metabolic changes as a result of icterus the author in his own case the relieved drainage of the bilio digestive anastomosis solved by the help of a polyethylene nasal tube and which could be most safely removed by the surgeon with statistical data of other authors and personal cases the author points out that the correctable cases occur in 19 8 of all the cases one may hope for successful operations on an average in 10 2 of all the cases and 50 8 of the correctable ones fatal complications the author believes can be reduced by early surgery
MED	icterus neonatorum simplex studies in 50 guinea pigs demonstrate that at birth there is no activity of glucuronyltransferase after birth activity gradually increases and reaches its highest level on the 3rd day of life hereafter a gradual decrease can be shown the suggestion is made that glucuronyltransferase is an adaptive enzyme the results support the hypothesis that neonatal jaundice is caused by an inability of the liver of the newborn to excrete bilirubin
MED	the importance of steroid hormones in hyperbilirubinemia and icterus of the newborn administration of naturally occurring steroids estriol pregnanediol cortisone between the 7th and the 11th day of life increases the bilirubin level of these newborns administration of the same steroids or of progesterone to nursing mothers results in hyperbilirubinemia of their infants these facts explain the pathogenesis of neonatal jaundice interpretation of the experimental and clinical findings leads to the conclusion that the high amount of steroid hormones which must be excreted during the neonatal period in conjunction with the relative insufficiency of the neonatal liver is responsible for the inability to conjugate bilirubin with glucuronic acid the steroid hormones probably compete with bilirubin for the enzyme and substrate necessary for conjugation the functional capacity of the neonatal liver is not high enough to conjugate both bilirubin and steroids only after excretion of the placental steroids does sufficient conjugation of bilirubin become possible furthermore pregnanediol appears to inhibit the enzyme glucuronyl transferase these mechanisms show the importance of steroid hormones in the pathogenesis of neonatal jaundice and their importance as an aggravating factor in the development of jaundice due to erythroblastosis these newly developed concepts may have therapeutic implications on which the author will report at a later date
MED	problems in neonatal obstructive jaundice a critical analysis of 57 cases of neonatal obstructive jaundice led to the conclusion that proper diagnosis can be determined by study of liver biopsy the very low percentage of surgically correctable lesions among patients with neonatal obstructive jaundice and the seriousness and high mortality of the cases of hepatitis treated with a hazardous operation are stressed conservative management is recommended until 3 mth of age and even later if a serial fall in bilirubin is noted
MED	clinical study and histological study of the liver in hepatitis in infants i classification and findings of clinical study and histological study of the liver in hepatitis in infants japanese clinical observations and histological studies by liver biopsy on hepatitis in infancy i e obstructive jaundice of unknown cause in infants were made histologically hepatitis in infancy was divisible into 3 types 1 no giant cell formation was observed in general slight degeneration of liver cells necrosis and inflammatory changes with stasis of bile were characteristic 2 the so called giant cell hepatitis was characteristic 3 specific type presenting the picture of cholangiolitis histological changes in the liver other than biliary stasis were scanty no specific changes which could clinically differentiate the 3 types were found in each type serum bilirubin sgot and sgpt activities had slight characteristic points in clinical and laboratory studies in type 1 the values were relatively low while in type 2 they were markedly high in type 3 sgot activity was within normal range histological characteristics of the liver of type 1 were necrosis of liver cells formation of acidophilic granules and balloon cells cellular infiltration in glissons capsule and biliary stasis in the liver cells and fine bile ducts morphologically findings of viral hepatitis were observed in type 2 liver tissue was replaced by many multinuclear giant cells extreme distortion of cords of liver cells and cellular infiltration in glissons capsule and lobules were noted there was marked biliary stasis in the capillary bile ducts and liver cells it was characteristic that proliferation of bile ducts and bile plugs were not found which was consistent with giant cell hepatitis of craing landing in type 3 degeneration of liver cells necrosis and inflammatory changes were slight biliary stasis in the hepatic lobules was conspicuous histological findings similar to cholangiolitic hepatitis due to drug poisoning were observed
MED	the pathology of giant cell hepatitis in early infancy a 1 month old male infant was admitted to hospital because of acute cardiac and circulatory failure autopsy revealed macronodular liver cirrhosis with splenomegaly left ventricular dilatation of the heart hydrothorax and ascites histology of the liver showed a giant cell hepatitis the portal areas were widened with foci of erythropoiesis and histiocytic infiltrations the liver cells showed vacuolar and degenerative changes the giant cells present in the margin of the regeneration areas as well as in the degenerated lobules has irregular borders and varied in size from 45 60 ft their nuclei were large sometimes bizarre their basophile cytoplasm showed granules of iron pigment which was also found in some normal hepatic cells in the prominent kupffer cells and in the connective tissue in the spleen there were proliferation of connective tissue and scattered areas of erythropoiesis as well as pigment deposits in the pulpa iron pigment was also found in the pancreas and salivary glands the islets of langerhans were hyperplastic the etiology of giant cell hepatitis is still unknown its pathogenesis may be due to a malformation immunologic response to some type of antibody inborn errors of iron metabolism and viral infection it is suggested that the giant cell transformation is a response of the immature liver cell to a variety of stimuli this case is of interest for the predominance of giant cells with 1 or 2 nuclei presumably it is an intermediate stage or a variant of hepatitis
MED	the surgery of infantile obstructive jaundice the results of suruga yamazakis procedure in 14 cases of congenital biliary duct atresia are reported postoperative anorexia diarrhea or edema due to circulatory disturbance in the upper extremity have not been found after this operation the operation is technically difficult postoperative fat protein and electrolyte metabolism is a problem in order to obtain better results this disease should be differentiated at an early period a long term follow up and continued study of this problem is required
MED	transient familial neonatal hyperbilirubinemia a syndrome of transient familial neonatal unconjugated hyperbilirubinemia not due to known causes has been described in 24 infants of 8 unrelated healthy caucasian mothers four of the infants developed kernicterus beginning in the 2nd trimester of pregnancy sera from the 8 mothers and their newborn infants inhibited direct reacting bilirubin and o aminophenol glucuronide formation by rat liver slices and homogenates respectively 4 to 10 times more than was observed with sera from a control group of pregnant women and their infants the serum inhibitory factor in these women is unidentified the fact that the inhibitor occurs in pregnancy serum suggests that it is probably a progestational steroid that inhibits glucuronyl transferase activity in the liver of neonates the mechanism responsible for increased serum inhibitor factor activity in these women is unknown and requires further study
MED	hepatitis virus in neonatal liver disease liver biopsy specimens from 3 babies with neonatal hepatitis and 3 with extrahepatic biliary atresia were studied for the presence of hepatitis virus culture yielded positive results in all 3 babies with neonatal hepatitis and in 1 of the infants with biliary atresia
MED	neonatal hepatitis liver biopsy findings and clinical features on 22 infants with a clinical diagnosis of neonatal hepatitis histologic examination of the liver was made by needle biopsy and its relation to the clinical course was investigated histologic findings were classified provisionally into 3 types type i showed no giant cells but only slight damage to hepatic cells with prominent intracellular cholestasis type ii was characterized by occurrence of numerous giant cells the specific type was characterized by centrolobular cholestasis without inflammatory reaction laboratory examinations revealed that increases in serum transaminases and bilirubin were greater in type ii than in type i and in the specific type there was no increase in serum transaminase but there was a direct hyperbilirubinemia as to histologic sequelae the results of serial biopsy revealed that in type i hepatic damage healed almost completely and that in type ii giant cells disappeared within 1 yr and in some cases hepatic cirrhosis resulted the prognosis of neonatal hepatitis may be said to be good in type i poor in type ii and undetermined in the specific type
MED	spherocytic anemia with early deglobulisation crisis and avitaminosis a from birth 2 homozygous male twins had had a series of hemolytic crises these caused a low crythrocyte count and jaundice on the one hand and xerophthalmia probably owing to the existence proven by liver biopsy of a complicating obstructive biliary syndrome on the other
MED	neonatal hepatitis or familial neonatal obstructive jaundice four siblings all of whom were boys with chronic obstructive jaundice are described the onset of the jaundice varied from 1 day to 4 weeks after birth two other boys and 2 girls in the same family are healthy although in one of the 4 cases pathological findings were the same as in neonatal hepatitis giant cell hepatitis other possibilities could not be excluded what has been described hitherto as giant cell hepatitis appears to be only a morphological picture for which there must be several causes it is concluded from the findings in the 4 patients that one of the possible causes of so called giant cell hepatitis is an inborn error of metabolism
MED	hypoplasia of the intrahepatic bile ducts a description of 2 cases 1 a boy of 13 days old had atresia of the small intestine and pneumonia and a slightly enlarged liver with faint green coloration histological examination revealed numerous collapsed bile ducts which had solid ductular cell sprouts reaching the liver cells the minor and smallest bile ducts were empty 2 a girl of 1 yr and 4 mth had increasing jaundice since birth autopsy revealed a hypoplastic common bile duct which was however open to probing and marked green coloration of the liver also in this case the bile ducts were very narrow and had solid ductular cell sprouts reaching the liver cells this type of bile duct corresponds to a stage in ontogenesis and does not show signs of proliferation it may be considered a form of hypoplasia as the size and number of the primordial bile ducts is reduced when present the anlage shows a regular connection with the liver cells this hypoplasia is to be distinguished from an atresia the long survival of the second case can be explained by the great compensatory capacity of the liver
MED	fetal and neonatal hepatitis and its consequences the author reports on 18 fatal cases observed in infants from 3 weeks to 1 year old in all cases jaundice appeared just after birth or during the first days of life and was persistent the stools were sometimes discolored there was no blood incompatibility the picture was similar to that of congenital biliary atresia pathological study revealed 2 groups 1 with pathological changes of hepatitis 11 cases the liver is enlarged flabby and icteric microscopy shows dissociation of the cell cords and polymorphism of the hepatic cells necrotic cells balloon cells giant cell transformation some of the giant cells show vacuoles erythrocytes lipids and acidophilic material in their cytoplasm there are signs of regeneration collapse of the stromal framework proliferation of the mesenchymal cells and bile retention cells of the erythrocytic series are scattered in the periportal spaces with eosinophilic leucocytes lymphocytes and histiocytes 2 with fibrosis and cirrhosis 7 cases the liver is green firm with a nodular or granular surface the extra hepatic biliary tree is normal the spleen is enlarged microscopy shows bile stasis pericholangiolitic fibrosis and proliferation of bile ductules the periportal interlobular and intralobular fibrous tissue is increased and shows cellular infiltrations the architecture of the liver is disturbed by the presence of pseudolobuli in the regeneration areas it is suggested that these cases are due to a congenital viral hepatitis which is not only the result of an intrauterine infection but also a feature of fetal hepatitis with secondary pericholangiolitic or post necrotic liver cirrhosis the neonatal giant cell hepatitis is to be considered as the result of a cytotoxic action of the virus the author considers also the possibility of a viral etiology in cases of biliary atresia on the basis of their morphological similarity with congenital viral hepatitis
MED	metabolism and excretion of bilirubin c in experimental obstructive jaundice bile duct ligation was carried out in a series of rhesus monkeys the time required for the serum bilirubin to stop rising and achieve a relatively stable level and the average serum bilirubin reached paralleled closely that seen clinically after the serum bilirubin levels had stopped rising and a steady state had been reached radioactive bilirubin was injected i v the radioisotope was distributed principally extravascularly and not in the same ratio as albumin as in other forms of jaundice daily turnover of bilirubin was found to be double that anticipated from normal hb breakdown suggesting increased bilirubin production in obstructive jaundice in animals followed for 2 wk nearly 80 of injected radioactivity was excreted in the urine indicating that in obstructive jaundice the kidney takes over entirely from the liver the function of bilirubin excretion
MED	major surgery on the severe hemophiliac lessons in management three cases of pseudotumor of the thigh which required surgical amputation and one case of open pericardial drainage for cardiac tamponade are briefly reported in severe hemophiliacs in the first case hemostasis following amputation was produced but the patient died of septicemia secondary to proximally infected tissues the level of amputation should therefore be proximal to all grossly infected tissues in the second case with infected massive pseudotumor of the left thigh 5 separate operative procedures were performed the last procedure was elective revision of skin flaps at the hip disarticulation site here application of the knowledge gained from previous experience resulted in a completely uncomplicated postoperative course by dint of timing of the surgical procedure in relation to control of infection loss of plasma fastness and the judicious use of antibiotic and direct current electrocoagulation therapy a plea is made to avoid the use of plasma and ahg therapy in hemophilias for trivial reasons and to consider patients for surgical procedures early in the course of their complications which demand surgery at a time when the patient is still responsive to hematologic therapy and prior to the onset of infection in areas of hematoma it is felt that a second significant hemorrhage in any particular site constitutes a bona fide indication for surgical intervention long before the time when surgery is considered as the last resort by the physician patient and family although the authors believe that surgery in the hemophiliac is not to be taken lightly they do not endorse the prevailing nihilistic attitude that has resulted in temporizing delays which can only guarantee a fatal outcome
MED	immunological demonstration of factor viii protein in the plasma of hemophiliacs and its value for an insight into hemophilia a by immunization of rabbits one obtains antisera against human factor viii the action of the immunsera has been determined using a modification of the thromboplastingenerations test the factor viii neutralization test the antibodies against factor viii are equally absorbed by either normal or hemophilia a plasma this observation shows that hemophilia a plasma contains as much factor viii protein as normal plasma does in normal and hemophilia a serum one finds at a lower level similar concentrations of factor viii in analogy with cross reacting substances crm in bacteria mutants an hypothesis has been made according to which the authors are dealing with the product of a genetically altered synthesis of factor viii this product is functionally less active but possesses the same antigenic determinants as the normal factor viii some inhibitor properties of the hemophilia plasma can be explained by competitive inhibition made possible by the similarity of structure the fact that the inhibitor discovered by mammen and factor viii have similar properties support the hypothesis the theory of some authors according to which the plasma of an hemophiliac a contains normal amounts of a normal factor viii blocked by a specific inhibitor the pathogenetic agent of hemophilia a is rejected because of genetic considerations and because the accelerator appearing after ether treatment of hemophilia a plasma is not identical with factor viii
MED	haemophilic pseudotumours 3 cases the 2 first cases of haemophilic pseudo tumours in 2 adults affected with haemophilia a reported are remarkable on account of their clinical latency and their intertrochanteric localization the third in a haemophiliac b is very extensive and is accompanied by very marked clinical symptoms of tumour there is an extensive femoral gap with a subjacent image of osseous infarction and a progressive turgid tumour of the iliac wing of the same side the literature data stress the discrepancy between the progressive character of this veritable tumour and the absence of any sign of histological malignancy
MED	protein losing enteropathy complicating prolonged bleeding in hemophilia gastrointestinal bleeding in a severe hemophiliac continued for 110 days and 263 pints of fresh blood were replaced treatment with eaca steroids and factor viii rich fibrinogen did not control bleeding marked hypoproteinemia developed by the 94th day of bleeding a protein losing enteropathy was suspected on the basis of x ray findings of mucosal thickening and altered motility discontinuance of steroids and protein replacement resulted in the appearance of a more normal small bowel mucosal pattern and coincided with the cessation of bleeding
MED	bilateral hemophilic pseudotumors of the calcaneus and cuboid treated by irradiation case report a case is presented in which bilateral pseudotumors of the calcaneus and cuboid in an 11 year old boy with apparent classic hemophilia responded promptly to deep x ray therapy with relief of pain and subsequent disappearance of the tumors without recurrence for 2 yr and 8 mth after treatment although previous reports on the effects of radiotherapy for pseudotumors have been conflicting the results in this case were dramatic
MED	some bone lesions in the course of blood diseases with special reference to the formation of bony callus and to the treatment of fractures in patients suffering from blood diseases after some preliminary remarks on the embryology and physiology of the bone marrow and on the mechanism of coagulation of the blood the authors pass on to a consideration of the genesis of bony callus and the treatment of fractures in patients suffering from blood diseases an account is given on the basis of some examples of pathological fractures and also of some traumatic fractures in subjects affected by various kinds of blood diseases such as solitary myeloma polyosteotic plasmocytoma waldenstroems syndrome the coagulopathic syndrome from a structural defect of the fibrin coagulum and hemophilia fractures in patients with blood diseases are characterized by an abnormal course and for an effecient cure it is necessary to make an accurate diagnosis with regard to the pre existing blood diseases and to re establish hemostasis when this has been changed to prevent hemorrhages and to correct any plasma defect that may be present and which are reflected in the formation of the bony callus
MED	studies of the antihemophilic factor ahf factor viii produced in von willebrands disease it has been confirmed that persons with autosomal ahf deficiency von willebrands disease produce large quantities of ahf when transfused with ahf deficient plasma from persons with hemophilia a this occurs despite the fact that complementation does not occur in vitro one prediction from a model suggesting that the x locus for ahf is structural while the autosomal locus is regulatory is that the ahf which appears in von willebrands disease after transfusion will be structurally normal the ahf obtained under these conditions has been tested by methods and the results fulfil the prediction this may imply that the model is correct on the other hand the prediction may have been fulfilled for other reasons perhaps the wrong parameters were examined or the large standard errors of the tests masked a real difference further tests are obviously needed before one can feel reasonably certain that mutation of a regulatory gene is the basis of von willebrands disease an examination of persons with sex linked and autosomal ahf deficiency using an antibody prepared against wild type ahf might be very illuminating also transfusion studies should be carried out on persons homozygous for von willebrands disease if such persons can be found failure to obtain new synthesis in a homozygote would throw great doubt on a model which implies that the reduced ahf levels in von willebrands disease heterozygotes is due entirely to reduction in an effector substance which neutralizes the repressor of an x chromosome operon directly coding the ahf molecule
MED	tumor like bone lesions in hemophilia this report deals with the clinical and radiologic findings in a hemophilic pseudotumor of the femur observed over a period of 10 yr the pathogenesis treatment and radiologic differential diagnosis are discussed
MED	concurrent hemophilia and christmas disease in one family a study is presented of a number of generations of a family in whom two members had christmas disease and three hemophilia a it is suspected that the preceding generations must have been afflicted with hemophilia ab or a mutation in x chromosome genes which are responsible for both types of hemophilia must have occurred in the grandmothers family in her daughters the genes responsible for hemophilia ab segregated so that their children and grandchildren inherited only one type of hemophilia i e hemophilia a or christmas disease relevant genetic considerations are briefly reviewed
MED	albinism associated with angiohemophilia report of a case a case is presented of a rare association of albinism and angiohemophilia occurring in a man of 25 the bone marrow contained cells resembling proper reticulum cells and containing large basophilic granules
MED	major surgery in classic hemophilia using fraction i experience in twelve operations and review of the literature a therapeutic regimen that provides hemostasis in hemophiliacs during and after major surgery without requiring laboratory control has been established with a factor viii concentrate the effectiveness of this regimen of fraction i therapy was evaluated in major surgery of 6 severely deficient and 4 moderately deficient hemophiliacs an analysis of clinical results was made combining the 12 operations of the series with the 116 major operative procedures on hemophiliacs recorded in the english literature in which fraction i was the sole or major source of factor viii therapy dental and nondental surgery were analyzed separately as was the special problem of blood cysts although the over all mortality rate following major surgery in hemophiliacs is presently only 5 to 10 using factor viii concentrates problems still remain these include the continued high incidence of abnormal postoperative hemorrhage the variation in factor viii potency of different lots of fraction i the late development of serum hepatitis hemolytic anemia due to contaminating isoantibodies and the high cost of adequate amounts of the product more efficient methods of preparing purer and more potent factor viii concentrates could eliminate most of these difficulties
MED	lengthening of the thrombin time by an anti equine antithrombin in a hyperthrombocyte myelosis a report is given on a patient treated with numerous i m injections of thrombase equine thrombin for chronic gingivorrhagia caused by a hyperthrombocytic myelosis these were ineffective and an antithrombin specific against equine thrombin had developed this did not cause any specific disturbance of the intrinsic coagulation the observation can be compared with two cases of haemophilia where such an antithrombin had also developed after repeated injections of equine thrombin
MED	epsilon aminocaproic acid e aca as a therapeutic agent based on 5 years clinical experience experience in the treatment of 744 patients with e aca suggested that the use of the preparation is indicated in the following situations 1 fibrinolytic haemorrhage in association with delivery 2 acute systemic fibrinolysis in association with surgery it is mainly major operations on the thorax pancreas prostate liver and genital organs that are complicated by fibrinolysis but fibrinolytic bleedings can occur after any operation 3 acute systemic fibrinolysis in patients with cancer particularly cancer of the prostate and pancreas 4 systemic fibrinolytic states complicating various disorders especially leukaemia liver cirrhosis and boecks sarcoid 5 as an antidote in thrombolytic therapy 6 local fibrinolytic activity in the urinary tract in the following situations a after prostatectomy e aca will substantially reduce blood losses following prostatectomy especially if the treatment is continued until the urine has become macroscopically clear b haematuria in prostatic cancer prostatic hyperplasia prolonged haematuria after traumatic injury of the kidney haematuria in haemophilia and other coagulation defects and so called essential haematuria 7 ulcerative colitis the drug is equally effective whether given orally or intravenously in states with increased systemic fibrinolytic activity a dose of 0 1 g per kg body weight every 4 5 hours is recommended for inhibition of local fibrinolytic activity in the urinary tract a dose of 3 g three times a day has proved sufficient the side effects consisted of dizziness nausea and diarrhoea no toxic effects of the drug on e c g blood picture n p n and liver function tests were observed not even in cases receiving more than 1000 g of e aca nor did postmortem examination in 46 cases reveal any signs of a toxic effect no signs of intravascular coagulation in connection with e aca therapy were observed the incidence of thromboembolic complications after prostatectomy in patients treated with e aca and a series of controls was identical judging from the authors experience in this material e aca did not act as an agent inducing thrombosis
MED	femoral neuropathy in hemophilia six new cases of femoral neuropathy in hemophilic patients are described the syndrome begins with severe pain in the groin in the inferior aspect of the thigh and deep in the hip region this is followed by a pronounced contracture of the hip in flexion and external rotation a tender swelling appears in the iliac fossa and groin with a depression in the center corresponding to the inguinal ligament finally a flaccid paralysis of the quadriceps femoris and diminution or absence of sensation in the anteromedial aspect of the thigh and proximal portion of the leg with a depressed or absent patellar reflex is discovered the authors propose that this syndrome is the result of hemorrhage in the iliopsoas muscle at the musculotendinous junction beneath the iliacus fascia and that the femoral nerve becomes compressed beneath the unyielding inguinal ligament superiorly and the iliopectineal ligament medially treatment consists in bed rest analgesics and freshfrozen plasma during the acute phase during the convalescent phase a hessing long brace is used to protect the knee from hemarthrosis until functional return of the quadriceps femoris has occurred to date the validity of the theory that the femoral nerve palsy is the result of iliopsoas hemorrhage at the musculotendinous junction and compression of the femoral nerve beneath the inguinal ligament has not been verified the authors anticipate some day seeing a non hemophilic patient with a traumatic iliacus hemorrhage and femoral neuropathy should such an opportunity present itself exploration beneath pouparts ligament may show the femoral nerve to be compressed and thus confirm the proposed cause of the clinical picture
MED	hemorrhagic episodes in hemophilia a 5 year prospective study medicosocial studies of hemophilia are of particular clinical importance in allowing an assessment of the likely course of the disease at different ages and for differing grades of severity and in providing knowledge of which complications cause the most disability loss of education and earning capacity they also overcome the distorted clinical impression of the disease which arises from the recurrent admission of the same few severely affected hemophiliacs owing to the considerable individual variation in the number and severity of complications in different hemophiliacs an accurate individual prognosis can never be given in general however the number of spontaneous episodes per year decreases with age while the severity of individual episodes tends to increase at least until the age of 21 yr there is general agreement that the bulk of hospital hemophilic admissions are due to hemarthroses and that hemophilic arthropathy involves the knee more than it does any other joint the increased time spent in hospital per episode in later life is in part at least due to the development of relatively unstable weight bearing joints due to hemophilic arthropathy and associated muscle atrophy thus the correct management of individual hemarthroses in childhood is of considerable importance and at the present time too little is known of the best possible treatment for these episodes little is known of the pathological mechanisms of hemophilic arthropathy and whether it is the presence of blood or its presence under tension which leads to joint destruction thus opinions differ concerning the routine admission of all hemarthroses to hospital regardless of severity and also about the advisability of joint aspiration in an attempt to avoid the development of destructive arthropathy because of the individual variation between patients the changes in the pattern of the disease with age and the difficulty of obtaining suitable control patients these questions can be answered only by further longterm prospective medicosocial studies
CRAN	experimental investigation of the aerodynamics of a wing in a slipstream experimental investigation of the aerodynamics of a wing in a slipstream an experimental study of a wing in a propeller slipstream was made in order to determine the spanwise distribution of the lift increase due to slipstream at different angles of attack of the wing and at different free stream to slipstream velocity ratios the results were intended in part as an evaluation basis for different theoretical treatments of this problem the comparative span loading curves together with supporting evidence showed that a substantial part of the lift increment produced by the slipstream was due to a destalling or boundary layer control effect the integrated remaining lift increment after subtracting this destalling lift was found to agree well with a potential flow theory an empirical evaluation of the destalling effects was made for the specific configuration of the experiment
CRAN	simple shear flow past a flat plate in an incompressible fluid of small viscosity simple shear flow past a flat plate in an incompressible fluid of small viscosity in the study of high speed viscous flow past a two dimensional body it is usually necessary to consider a curved shock wave emitting from the nose or leading edge of the body consequently there exists an inviscid rotational flow region between the shock wave and the boundary layer such a situation arises for instance in the study of the hypersonic viscous flow past a flat plate the situation is somewhat different from prandtls classical boundary layer problem in prandtls original problem the inviscid free stream outside the boundary layer is irrotational while in a hypersonic boundary layer problem the inviscid free stream must be considered as rotational the possible effects of vorticity have been recently discussed by ferri and libby in the present paper the simple shear flow past a flat plate in a fluid of small viscosity is investigated it can be shown that this problem can again be treated by the boundary layer approximation the only novel feature being that the free stream has a constant vorticity the discussion here is restricted to two dimensional incompressible steady flow
CRAN	the boundary layer in simple shear flow past a flat plate the boundary layer in simple shear flow past a flat plate the boundary layer equations are presented for steady incompressible flow with no pressure gradient
CRAN	approximate solutions of the incompressible laminar boundary layer equations for a plate in shear flow approximate solutions of the incompressible laminar boundary layer equations for a plate in shear flow the two dimensional steady boundary layer problem for a flat plate in a shear flow of incompressible fluid is considered solutions for the boundary  layer thickness skin friction and the velocity distribution in the boundary layer are obtained by the karman pohlhausen technique comparison with the boundary layer of a uniform flow has also been made to show the effect of vorticity
CRAN	one dimensional transient heat conduction into a double layer slab subjected to a linear heat input for a small time internal one dimensional transient heat conduction into a double layer slab subjected to a linear heat input for a small time internal analytic solutions are presented for the transient heat conduction in composite slabs exposed at one surface to a triangular heat rate this type of heating rate may occur for example during aerodynamic heating
CRAN	one dimensional transient heat flow in a multilayer slab one dimensional transient heat flow in a multilayer slab in a recent contribution to the readers forum wassermann gave analytic solutions for the temperature in a double layer slab with a triangular heat rate input at one face insulated at the other and with no thermal resistance at the interface his solutions were for the three particular cases i propose here to give the general solution to this problem to indicate briefly how it is obtained using the method of reference 2 and to point out that the solutions given by wassermann are incomplete for times longer than the duration of the heat input
CRAN	the effect of controlled three dimensional roughness on boundary layer transition at supersonic speeds the effect of controlled three dimensional roughness on boundary layer transition at supersonic speeds experiments were performed in the 12 in supersonic wind tunnel of the jet propulsion laboratory of the california institute of technology to investigate the effect of three dimensional roughness elements spheres on boundary layer transition on a tained at local mach numbers of 1 90 2 71 and 3 67 by varying trip size position spacing and reynolds number per inch the results indicate that 1 transition from laminar to turbulent flow induced by three dimensional roughness elements begins when the double row of spiral vortices trailing each element contaminates and breaks down the surrounding field of vorticity 2 transition appears rather suddenly becoming more violent with increasing roughness height relative to the boundary layer thickness 3 after the breakdown of the vorticity field the strength of the spiral vortices may still persist in the sublayer of the ensuing turbulent flow 4 lateral spacing of roughness elements has little effect upon the initial breakdown contamination of the laminar flow and 5 the trip reynolds number where u and v are the velocity and kinematic viscosity at the outer edge of the boundary layer and k is roughness height such that transition occurs at the roughness position varies as the position reynolds number to the one fourth power viz where x is trip position
CRAN	measurements of the effect of two dimensional and three dimensional roughness elements on boundary layer transition measurements of the effect of two dimensional and three dimensional roughness elements on boundary layer transition in his study of the effect of roughness on transition h l dryden found on the basis of available data that the effect of a two dimensional roughness element such as a trip wire could be represented reasonably well in terms of a functional relation between and where is the reynolds number of transition based on distance from the leading edge is the height of the roughness element and is the boundary layer displacement thickness at the position of the element at his suggestion some additional data were obtained primarily to extend the range to higher values of during the course of an investigation of transition on a flat plate conducted at the national bureau of standards after the results on the two  dimensional roughness elements were obtained it appeared to be desirable to see whether a row of three dimensional roughness elements would behave in the same way
CRAN	transition studies and skin friction measurements on an insulated flat plate at a mach number of 5 8 transition studies and skin friction measurements on an insulated flat plate at a mach number of 5 8 an investigation of transition and skin friction on an insulated flat plate 5 by 26 in was made in the galcit 5 by 5 in hypersonic wind tunnel at a nominal mach number of 5 8 the phosphorescent lacquer technique was used for transition detection and was found to be in good agreement with total head rake measurements along the plate surface and pitot boundary  layer surveys it was found that the boundary layer was laminar at reynolds numbers of at least 5 x 10 transverse contamination caused by the turbulent boundary layer on the tunnel sidewall originated far downstream of the flat plate leading edge at reynolds numbers of 1 5 to 2 x 10 and spread at a uniform angle of 5 compared to 9 degree in low speed flow the effect of two dimensional and local disturbances was investigated the technique of air injection into the boundary layer as a means of hastening transition was extensively used although the onset of transition occurred at reynolds numbers as low as 10 a fully developed turbulent boundary layer was not obtained at reynolds numbers much below 2 x 10 regardless of the amount of air injected a qualitative discussion of these results is given with emphasis on the possibility of a greater stability of the laminar boundary layer in hypersonic flow than at lower speeds direct skin friction measurements were made by means of the floating element technique over a range of reynolds numbers verified as being laminar over the complete range with air injection turbulent shear was obtained only for reynolds numbers greater than 2 x 10 this value being in good agreement with earlier results of this investigation the turbulent skin friction coefficient was found to be approximately 0 40 of that for incompressible flow for a constant value of r and 0 46 for an effective reynolds number between 5 and 6 x 10
CRAN	the theory of the impact tube at low pressure the theory of the impact tube at low pressure a theoretical analysis has been made for an impact tube of the relation between free stream mach number and the impact and free stream pressures and densities for extremely low pressures it is shown that the results differ appreciably from the corresponding continuum relations
CRAN	similar solutions in compressible laminar free mixing problems similar solutions in compressible laminar free mixing problems there are in supersonic aerodynamics many situations of practical interest wherein streams of different velocities and in general different stagnation pressures mix with one another in the majority of these problems the interaction between the two streams takes place in the presence of an axial pressure gradient its effect on the characteristics of the mixing may influence significantly the performances of the devices wherein the phenomena cited above occur a theoretical and experimental program of research to study mixing in the presence of axial pressure gradients is being carried on at the polytechnic institute of brooklyn
CRAN	some structural and aerelastic considerations of high speed flight some structural and aerelastic considerations of high speed flight the dominating factors in structural design of high speed aircraft are thermal and aeroelastic in origin the subject matter is concerned largely with a discussion of these factors and their interrelation with one another a summary is presented of some of the analytical and experimental tools available to aeronautical engineers to meet the demands of high speed flight upon aircraft structures the state of the art with respect to heat transfer from the boundary layer into the structure modes of failure under combined load as well as thermal inputs and acrothermoelasticity is discussed methods of attacking and alleviating structural and aeroelastic problems of high speed flight are summarized finally some avenues of fundamental research are suggested
CRAN	similarity laws for stressing heated wings similarity laws for stressing heated wings it will be shown that the differential equations for a heated plate with large temperature gradient and for a similar plate at constant temperature can be made the same by a proper modification of the thickness and the loading for the isothermal plate this fact leads to the result that the stresses in the heated plate can be calculated from measured strains on the unheated plate by a series of relations called the similarity laws the application of this analog theory to solid wings under aerodynamic heating is discussed in detail the loading on the unheated analog wing is however complicated and involves the novel concept of feedback and body force loading the problem of stressing a heated box wing structure can be solved by the same analog method and is briefly discussed
CRAN	piston theory   a new aerodynamic tool for the aeroelastician piston theory   a new aerodynamic tool for the aeroelastician representative applications are described which illustrate the extent to which simplifications in the solutions of high speed unsteady aeroelastic problems can be achieved through the use of certain aerodynamic techniques known collectively as piston theory based on a physical model originally proposed by hayes and lighthill piston theory for airfoils and finite wings has been systematically developed by landahl utilizing expansions in powers of the thickness ratio and the inverse of the flight mach number m when contributions of orders and are negligible the theory predicts a point function relationship between the local pressure on the surface of a wing and the normal component of fluid velocity produced by the wings motion the computation of generalized forces in aeroelastic equations such as the flutter determinant is then always reduced to elementary integrations of the assumed modes of motion essentially closed form solutions are given for the bending  torsion and control surface flutter properties of typical section airfoils at high mach numbers these agree well with results of more exact theories wherever comparisons can be fairly made moreover they demonstrate the increasingly important influence of thickness and profile shape as m grows larger a discovery that would be almost impossible using other available aerodynamic tools the complexity of more practical flutter analyses e g on three dimensional wings and panels is shown to be substantially reduced by piston theory an iterative procedure is outlined by which improved flutter eigenvalues can be found through the successive introduction of higher order terms in and other applications to unsteady supersonic problems are reviewed including gust response and rapid maneuvers of elastic aircraft steady state aeroelastic calculations are also discussed but for them piston theory amounts only to a slight modification of ackerets formulas suggestions are made regarding future research based on the new aerodynamic method with particular emphasis on areas where computational labor can be reduced with a minimum loss of precision it is pointed out that a mach number zone exists where thermal effects are appreciable but nonlinear viscous interactions may be neglected and that in this zone piston theory is the logical way of estimating air loads when analyzing aerodynamic  thermoelastic interaction problems
CRAN	on two dimensional panel flutter on two dimensional panel flutter theory and experiments of the flutter of a buckled plate are discussed it is shown that an increase in the initial deviation from flatness or a static pressure differential across the plate raises the critical value of the reduced velocity the applicability of the galerkin method to the linearized problem of flutter of an unbuckled plate has been questioned by several authors in this paper the flutter condition was formulated in the form of an integral equation and solved numerically by the method of iteration and the method of matrix approximations thus avoiding the constraint of assumed modes for a plate with finite bending rigidity the results confirm those given by the galerkin method an approximate analysis of the limiting form and amplitude of the flutter motion for a buckled plate is presented
CRAN	transformation of the compressible turbulent boundary layer transformation of the compressible turbulent boundary layer the transformation of the compressible turbulent boundary  layer equations to their incompressible equivalent is demonstrated analytically the transformation is essentially the same as that for the laminar layer first given by stewartson except that the explicit relation between the viscosity and temperature is not required a key point in the analysis is the modification of the stream function to include a mean of the fluctuating components and the postulate that the apparent turbulent shear associated with an elemental mass remains invariant in the transformation the values of the incompressible friction coefficients and of pressure rise causing separation thus transformed show good agreement with the experimentally measured and independently reported results an application of the transformation to the self preserving boundary layers and to the computations of general boundary layer flow is shown
CRAN	remarks on the eddy viscosity in compressible mixing flows remarks on the eddy viscosity in compressible mixing flows in connection with a study of the wakes behind bodies in hypersonic flow carried out for the missile and space vehicle division of the general electric company it was desired to estimate the eddy viscosity in axisymmetric compressible wakes because of the lack of applicable experimental data it was found necessary to make such an estimate by rationally extending the few available data for incompressible flows to the compressible case this suggested the application and extension of the transformations applied to turbulent boundary layers in reference infinitesimal mass are invariant with transformation mager showed that the partial differential equations for the compressible turbulent boundary layer can be transformed to incompressible form the validity of this assumption and of the transformations was established for several boundary layer flows by comparison with experiment
CRAN	the flow field in the diffuser of a radial compressor the flow field in the diffuser of a radial compressor this note discusses the two dimensional diffuser flow field in a radial compressor outside the impeller wheel it is assumed that the diffuser has guide vanes arranged in a circular row at a radius the impeller wheel has the radius see fig 1 the flow in the diffuser starts at the circle with the radius the velocity components and in the r and directions of the velocity vector on this circle are prescribed together with the thermal state of the gas the flow so prescribed on the radius will if no disturbances are present i e no boundary conditions in the flow other than zero velocity at infinity are to be fulfilled develop in a spiral flow
CRAN	an investigation of the pressure distribution on conical bodies in hypersonic flows an investigation of the pressure distribution on conical bodies in hypersonic flows a large amount of work on conical flow fields without axial symmetry at supersonic speed is presently available however no apparent hypersonic approximation has yet been derived in this note experimental data on two elliptical cones at m 6 are presented and a hypersonic approach obtained from physical considerations is suggested
CRAN	generalised newtonian theory generalised newtonian theory author generalizes leess amr 10 1957 rev 2601 modification of newtonian theory for blunt nose bodies to apply to pointed  nose bodies as well the result is expressed by sin where is the local inclination of the body surface and the subscript max refers to the maximum local inclination and pressure coefficient for blunt nose bodies and the generalized theory reverts to leess blunt nose modification with given by normal shock relations author shows by comparison of newtonian and generalized newtonian theory with exact solutions the superiority of generalized newtonian theory he also shows that both two dimensional and axisymmetric shapes are correlated by this generalization results are presented in two figures that support authors generalization and indicate the independence of the correlation from variations in both the hypersonic similarity parameter k m d1 and the ratio of specific heats y reviewer believes this generalization should be of interest to those engaged in development of hypersonic hardware as well as theory
CRAN	on heat transfer in slip flow on heat transfer in slip flow a number of authors have considered the effect of slip on the heat transfer and skin friction in a laminar boundary layer over a flat plate reference 1 considers this by a perturbation on the usual laminar boundary layer analysis while some other studies dash e g reference the impulsive motion of an infinite plate
CRAN	on slip flow heat transfer to a flat plate on slip flow heat transfer to a flat plate assuming that continuum flow energy equation in a boundary layer remains valid well into slip region and taking account of the temperature jump in a moving rarefied gas and for influence of large mean free path through appropriate boundary conditions a solution is found for the temperature gradient in the slip region then from maslen expression j aero sci 25 6 400 401 june slipping fluid to a flat plate and behavior confirms results for small values of knudsen number
CRAN	skin friction and heat transfer characteristics of a laminar boundary layer on a cylinder in axial incompressible flow skin friction and heat transfer characteristics of a laminar boundary layer on a cylinder in axial incompressible flow a solution is given for the case of the laminar boundary layer of an incompressible fluid of constant properties on the exterior of a cylinder with flow parallel to the cylinder axis this case differs from the blasius solution for flow along a flat plate by considering the effect of the curvature in a plane transverse to the flow direction the local skin friction and heat transfer coefficients for a prandtl number of 0 715 are evaluated and compared to the similar magnitudes for flat plate flow and the effect of the curvature is shown to be significant in some practical cases recovery factors are evaluated and this quantity is found to be insensitive to the effect of curvature of the boundary
CRAN	theory of stagnation point heat transfer in dissociated air theory of stagnation point heat transfer in dissociated air the boundary layer equations are developed in general for the case of very high speed flight where the external flow is in a dissociated state in particular the effects of diffusion and of atom recombination in the boundary layer are included it is shown that at the stagnation point the equations can be reduced exactly to a set of nonlinear ordinary differential equations even when the chemical reactions proceed so slowly that the boundary layer is not in thermochemical equilibrium two methods of numerical solution of these stagnation point equations are presented one for the equilibrium case and the other for the nonequilibrium case numerical results are correlated in terms of the parameters entering the numerical formulation so as not to depend critically on the physical assumptions made for the nonequilibrium boundary layer both catalytic to atom recombination and noncatalytic wall surfaces are considered a solution is represented which shows the transition from the frozen boundary layer very slow recombination rates to the equilibrium boundary layer fast recombination rates a recombination rate parameter is introduced to interpret the nonequilibrium results and it is shown that a scale factor is involved in relating the equilibrium state of a boundary layer on bodies of different sizes it is concluded that the heat transfer through the equilibrium stagnation point boundary layer can be computed accurately by a simple correlation formula and that the heat transfer is almost unaffected by a nonequilibrium state of the boundary layer provided the wall is catalytic and the lewis number near unity
CRAN	inviscid hypersonic flow over blunt nosed slender bodies inviscid hypersonic flow over blunt nosed slender bodies at hypersonic speeds the drag area of a blunt nose is much larger than the drag area of a slender afterbody and the energy contained in the flow field in a plane at right angles to the flight direction is nearly constant over a downstream distance many times greater than the characteristic nose dimension the transverse flow field exhibits certain similarity properties directly analogous to the flow similarity behind an intense blast wave found by g i taylor s c lin and a sakurai a comparison with the experiments of hammitt vas and bogdonoff on a flat plate with a blunt leading edge at in helium shows that the shock wave shape is predicted very accurately by this similarity analysis the predicted surface pressure distribution is somewhat less satisfactory experimental results on a hemisphere cylinder obtained at in the galcit air tunnel indicate that not only the shock wave shape but also the surface pressures for this body are given very closely by the similarity theory except near the hemisphere cylinder junction energy considerations combined with a detailed study of the equations of motion show that flow similarity is also possible for a class of bodies of the form provided that where for a two dimensional body and for a body of revolution when the shock shape is not similar to the body shape and the entire flow field some distance from the nose must depend to some extent on the details of the nose geometry by again utilizing energy and drag considerations one finds that at hypersonic speeds the inviscid surface pressures generated by a blunt leading edge are larger than the pressures induced by boundary layer growth on an insulated flat surface for an insulated blunt nosed slender body of revolution the corresponding distance is given by here is free stream reynolds number based on leading edge thickness or nose diameter in free flight these constants are replaced by 1 700 and 20 respectively so that viscous interaction effects are important over the forward portion of a blunt  nosed slender body only for relatively low values of however far downstream of the nose the inviscid over pressure is small and viscous interaction phenomena will have to be taken into account
CRAN	inviscid leading edge effect in hypersonic flow inviscid leading edge effect in hypersonic flow current interest in the problem of inviscid viscous interaction has led to the realization of the significant effect of the leading edge thickness in hypersonic flow the purpose of this note is to give an account of the downstream influence of the blunt leading edge on the basis of the hypersonic small perturbation theory
CRAN	newtonian flow theory for slender bodies newtonian flow theory for slender bodies as an aid to the aerodynamieist in the design of air frames for hypersonic speeds speeds faster than about mach 5 newtonian flow theory is examined from the point of view of gas dynamics and hypersonic small disturbance theory the usual theory is shown to result as the first approximation of an expansion valid for small a basic similarity parameter is introduced a general solution of the first approximation for the flow past slender bodies bodies which cause only a small disturbance to the stream at zero angle of attack is given an important condition which limits the application of the theory is noted namely that the pressure coefficient on the surface not fall to zero the theory is then applied to cones and to bodies whose shape is
CRAN	a note on the explosion solution of sedov with application to the newtonian theory of unsteady hypersonic flow a note on the explosion solution of sedov with application to the newtonian theory of unsteady hypersonic flow an exact analytical solution of the equations of inviscid compressible unsteady flow has been given by sedov reference to the solution may be made through hayes and probstein this solution is the similarity solution for a constant energy point explosion in view of the recent work on problems of hypersonic flow in the limiting form of the ratio of specific heats near 1 solution in this limit and inquire what form such a solution would take einbinder in a recent note has examined the solution for various but does not mention the interesting case of it may be shown that the convergence to the limit is nonuniform over the flow field it is also not difficult to show that the non  uniform behavior exhibited here is that which one would expect from the newtonian formulation as derived in reference 3
CRAN	a simple model study of transient temperature and thermal stress distribution due to aerodynamic heating a simple model study of transient temperature and thermal stress distribution due to aerodynamic heating the present work is concerned with the determination of transient temperatures and thermal stresses in simple models intended to simulate parts or the whole of an aircraft structure of the built  up variety subjected to aerodynamic heating the first case considered is that of convective heat transfer into one side of a flat plate representing a thick skin and the effect of the resulting temperature distribution in inducing thermal stresses associated with bending restraint at the plate edges numerical results are presented for the transient temperature differentials in the plate when the environment temperature first increases linearly with time and then remains constant the period of linear increase representing the time of acceleration of the aircraft corresponding thermal stress information is presented the second case is that of the wide flanged i beam with convective heat transfer into the outer faces of the flanges numerical results are presented for transient temperature differentials for a wide range of values of the applicable parameters and for an environment temperature variation as described above corresponding thermal stresses in a beam of infinite length are determined a theoretical analysis of the stress distribution in a beam of finite length is carried out and numerical results obtained for one case an experimental investigation of temperatures and stresses in such a beam is described and results are presented which indicate good agreement with corresponding theoretical results
CRAN	photo thermoelastic investigation of transient thermal stresses in a multiweb wing structure photo thermoelastic investigation of transient thermal stresses in a multiweb wing structure photothermoelastic experiments were performed on a long multiweb wing model for which a theoretical analysis is available in the literature the experimental procedures utilized to simulate the conditions prescribed in the theory are fully described correlation of theory and experiment in terms of dimensionless temperature stress time and biot number revealed that the theory predicted values higher than the experimentally observed maximum thermal stresses at the center of the web detailed temperature measurements in the flange suggested that the major source of this discrepancy can be traced to the one dimensional heat conduction analysis of the flange employed in the theory
CRAN	thermal buckling of supersonic wing panels thermal buckling of supersonic wing panels the temperature and thermal stress distributions are analyzed in multicellular supersonic wing structures a buckling criterion is established for the panels of cover plates subjected to thermal stresses
CRAN	the dynamic motion of a missile descending through the atmosphere the dynamic motion of a missile descending through the atmosphere a method is presented for computing rapidly yet accurately the dynamic motion of a ballistic type missile descending through the atmosphere the equations of motion are separated into a set of static trajectory equations zero angle of attack and a set of rotational equations describing the oscillatory motion of the missile about its center of gravity a transformation allows the rotational equations to be written in a manner analogous to the equation for an undamped oscillating spring mass system with the mass equal to unity and a time variable spring constant for given initial conditions this equation can be solved to obtain the envelope of maximum angle of attack an additional transformation allows the calculation of the complete oscillatory motion at any time during the trajectory as a function of the maximum angle of attack at that time this solution shows that the maximum angle of attack of a missile descending through the atmosphere at relatively constant speed is reduced even when the aerodynamic damping is neglected
CRAN	the prospects for magneto aerodynamics the prospects for magneto aerodynamics the equations describing the flow of an electrically conducting fluid in the presence of electric and magnetic fields are written down with the aid of certain simplifications appropriate to aeronautical applications in order to estimate the probable significance of magneto aerodynamic effects some data on conductivity of pure and seeded air are first examined dimensionless quantities representing the ratios of forces and of currents are then formed and their values studied for conditions of flight in the atmosphere some examples of magneto hydrodynamic and magneto  gasdynamic effects in simple flows are given these include two cases of poiscuille flow of conducting liquids with applied magnetic fields and the case of quasi one dimensional gas flow with applied electrical and magnetic fields in the last case attractive possibilities are found for controlled acceleration or deceleration of gas at subsonic and supersonic speeds even in constant area channels the behavior of the flow is characteristically different in different regimes of mach number and flow speed relative to certain significant speeds that are dependent on the ratio of electrical to magnetic field strengths these are studied and a chart is constructed to relate the length to the speed ratio of a maximum acceleration constant area channel it is concluded that the advantages that may accrue from magneto aerodynamic methods are sufficiently attractive to justify the considerable research and engineering development that will be required among the unsolved engineering problems are the reduction of surface resistance of electrodes in contact with a conducting gas development of techniques for seeding and provision of the required magnetic fields in flight
CRAN	constant temperature magneto gasdynamic channel flow constant temperature magneto gasdynamic channel flow in the course of investigating boundary layer flow in continuous plasma accelerators with crossed electric and magnetic fields it was found advantageous to have at hand simple closed form solutions for the magneto gasdynamic flow in the duct which could serve as free stream conditions for the boundary layers nontrivial solutions of this sort are not available at present and in fact as in the work of resler and sears the variation of conditions along the flow axis must be obtained through numerical integration consequently some simple solutions of magneto gasdynamic channel flow were sought possessing sufficient algebraic simplicity to serve as free stream boundary conditions for analytic investigations of the boundary layer in a physically reasonable accelerator in particular since the cooling of the accelerator tube is likely to be an important physical problem because of the high gas temperatures required to provide sufficient gaseous conductivity channel flow with constant temperature appears interesting some simple algebraic solutions for the case of a constant temperature plasma are developed in the following paragraphs
CRAN	stagnation point of a blunt body in hypersonic flow stagnation point of a blunt body in hypersonic flow the purpose of this paper is to present a method of calculation devised to yield all the important information on the symmetric inviscid hypersonic flow in the stagnation point region of a blunt body the problem is the same as that considered by hayes who used a slightly different approach it is demonstrated that hayes results are valid in the stagnation point region and can hence be considered a basis for constructing less restricted solutions equations are presented giving velocity pressure detachment distance and vorticity the values of shock detachment distance and body pressure coefficient are compared with experimental data for spheres the pressure comparison shows that the results of hayes and the theory presented herein represent a better approximation than the newtonian impact theory for hypersonic mach numbers in conclusion the possibility of refinements to this analysis is discussed
CRAN	supersonic flow around blunt bodies supersonic flow around blunt bodies the newtonian theory of impact has been shown to be useful for pressure calculations on the forward facing part of bodies moving at high speed it is now a familiar practice to use this information to calculate nonviscous velocities at the wall and then to estimate rates of heat transfer this procedure is perhaps open to question heat transfer rates depend on velocity gradients which are not given by the newtonian analysis nor can one obtain information on boundary layer stability or all the body stability derivatives it seems therefore inevitable that as design proceeds with these hypersonic missiles there will be a greater need for more accurate aerodynamic theories either to predict what will happen in unfamiliar flight conditions or to effect an extrapolation from a known test result to the design condition
CRAN	a new technique for investigating heat transfer and surface phenomena under hypersonic flow conditions a new technique for investigating heat transfer and surface phenomena under hypersonic flow conditions on the forebody of many practically interesting hypersonic vehicles there is little interaction between the inviscid flow field and the boundary layer therefore inviscid flow theory can be used to determine independent of surface phenomena the physically interesting quantities such as shock shape shock detachment distance sonic line shape and pressure distribution furthermore the pressure distribution so determined can then be used for the study of heat transfer materials behavior and other surface phenomena thus for these bodies the prandtl boundary layer concept can be utilized for the calculation of both the inviscid flow and the boundary layer behavior it is the purpose of this note to point out that this concept can also be applied experimentally in order to provide in conjunction with a conventional hypersonic wind tunnel air supply a means for investigating hypersonic heat transfer and surface phenomena under conditions of flight reynolds numbers
CRAN	on the prediction of mixed subsonic supersonic pressure distributions on the prediction of mixed subsonic supersonic pressure distributions high speed wind tunnel results are analyzed to derive a semiempirical scheme for the prediction of transonic pressure distributions the supersonic and subsonic parts of the flow are treated separately and then linked by an empirical shock pressure rise relation the significance of the empirical results is considered in relation to the physical mechanism of transonic flows it is also shown that theoretical solutions can be improved by introducing the empirical shock relation
CRAN	on the flow of a sonic stream past an airfoil surface on the flow of a sonic stream past an airfoil surface this study of the flow about an airfoil in a near sonic stream indicates the important factors determining the pressure distribution on the airfoil analysis of the mach wave pattern suggests that the supersonic domain of the flow can be derived from two simple wave flows one arising from the mach waves reflected at the sonic line and the other from the changes in airfoil surface slope the compressive effect of the reflected mach waves is determined quantitatively as a function of airfoil leading edge geometry from an analysis of measured pressure distributions for uncambered airfoils and it is shown how this can be superimposed on the wave system from the curved surface to give an equivalent simple wave flow over the airfoil an application of this scheme to the calculation of the pressure distribution over an airfoil in a sonic stream gives results in good agreement with experiment
CRAN	experiments on boundary layer transition at supersonic speeds experiments on boundary layer transition at supersonic speeds tests were conducted in the 12 in continuous supersonic wind tunnel of the jet propulsion laboratory california institute of technology to determine the effects of surface cooling on boundary layer transition at supersonic speeds the effects of cooling were investigated at test section mach numbers of 1 97 smooth cone in the presence of three levels of supply stream turbulence 0 4 2 and 9 per cent and several single element roughnesses at fixed axial location transition data were obtained optically by means of a magnified schlieren system the results for the range of mach number investigated indicate that 1 transition on a smooth cone can definitely be delayed by surface cooling 2 transition promoted by either supply stream turbulence or surface roughness can also be delayed by surface cooling depending upon degree of turbulence or relative roughness respectively and 3 the adverse effects of increased turbulence and roughness decrease with increasing mach number
CRAN	on transition experiments at moderate supersonic speeds on transition experiments at moderate supersonic speeds studies of transition over a flat plate at mach number 1 76 were carried out using a hot wire anemometer as one of the principal tools the nature and measurements of free stream disturbances at supersonic speeds are analyzed the experimental results are interpreted in the light of present overall information on transition at supersonic speeds and conclusions as to further fruitful experiments are drawn
CRAN	the gyroscopic effect of a rigid rotating propeller on engine and wing vibration modes the gyroscopic effect of a rigid rotating propeller on engine and wing vibration modes in many wing vibration analyses it is found necessary to take into account the effect of flexibly mounted engines hence it is reasonable to ask what vibratory gyroscopic effect this flexibility may give rise to when propellers are whirling an engine mount may be thought of as a horizontal beam cantilevered from the wing having both horizontal and vertical flexibility if this beam were infinitely rigid horizontally then when it vibrated the gyroscopic moments induced in the propeller due to the resultant pitching motion of its axis would not produce propeller axis yaw however engine mount lateral stiffness tical stiffness so that gyroscopic effects will play a role as the propeller axis undergoes pitching vibrations at the tip of the cantilever engine mount the purpose of this paper is to investigate this role under the assumption that the propeller itself is a rigid disc the paper is divided into four parts part 1 deals briefly with classical gyroscope theory part 2 presents engine vibration mode studies experimental photographic techniques on a model gyroscope mounted at the ends of two different cantilever beams part 3 presents the theory of the coupled motion of an elastic wing upon which a gyroscope is mounted to simulate an engine propeller system on an airplane part 4 consists of an example of the theory of part 3 in which by taking what are thought to be reasonable parameters results are obtained showing how the whirling of a rigid propeller may materially affect wing normal mode shapes and frequencies
CRAN	the relation between wall temperature and the effect of roughness on boundary layer transition the relation between wall temperature and the effect of roughness on boundary layer transition the experimentally demonstrated rise and subsequent fall of transition reynolds number with decreasing wall  to ambient temperature ratio has been the subject of two recent notes in both cases it was argued that the increased effectiveness of roughness due to wall cooling was not sufficient to explain the transition reversal phenomenon on nominally smooth bodies in one case the criterion for transition reversal was taken to be and in the other values of as low as eter is a reynolds number formed from velocity and kinematic viscosity based on calculated conditions at the height of roughness element k in the undisturbed laminar boundary layer at the station of roughness location the present note is submitted to show that another method for evaluating the effect of roughness on transition leads to an opposite conclusion
CRAN	tip bluntness effects on cone pressures at m 6 85 tip bluntness effects on cone pressures at m 6 85 there is at present considerable interest in the characteristies of blunted bodies from both an aerodynamic and a heat transfer standpoint the use of blunt shapes is contemplated to reduce the heat transfer problem at body noses but there are also applications for blunt noses which occur from mainly aerodynamic considerations an actual reduction in drag may be the beneficial result of blunting the nose of a cone or a similar slender shape under certain conditions although the sphere has received considerable treatment the nose shapes are not necessarily tangent spheres in the case let us say of a total head tube situated in the nose of a given body the blunting may be quite flat and nose sections blunter than spherical shape may conceivably be desirable in some cases from the heat  transfer standpoint the purpose of the present investigation is to examine the aerodynamic effect of a simple type of nose blunting on a basic body the incompressible flow of an electrically conducting fluid past a porous plate y 0 with constant suction velocity in the presence of a transverse uniform strength has recently been investigated by gupta in this note the problem is generalized to take into account the effect of free convection when a body force g per unit mass is acting in the negative x direction parallel to the wall the fluid is assumed to be semi  incompressible as usual in addition to the obvious practical significance this problem is also interesting in the sense that it provides another exact solution of the magnetohydrodynamic equations since the only electromagnetic assumptions involved are constant properties and freedom from excessive charges
CRAN	an investigation of separated flows part ii flow in the cavity and heat transfer an investigation of separated flows part ii flow in the cavity and heat transfer the first portion of this paper describes studies of the internal structure of the separated flow in a notch at a free stream mach number of 3 observations include flow visualization spark  schlieren pictures of the fluctuations of the free shear layer and studies of the diffusion of heat from sources placed in the separated region the second part describes measurements of local heat transfer to the wall the external mach number the length to depth ratio of the cavity the ratio of the oncoming boundary layer thickness to the notch depth in the turbulent flow region the thermal to momentum thickness ratio of the boundary layer and finally the geometry of the internal boundary of the separated region are varied as systematically as possible on the basis of these observations a simple model of the flow in and the heat transfer across the separated region is formulated
CRAN	some comments on the inversion of certain large matrices some comments on the inversion of certain large matrices the subject of matric structural analysis has been treated in two recently published papers in the journal the authors of these papers have made a number of statements about the inversion of certain large matrices it is the purpose of this note to bring to the attention of the reader certain facts that shed new light on this important problem it is shown here that the situation is not as hopeless as the above  mentioned authors intimate
CRAN	analysis of low aspect ratio aircraft structures analysis of low aspect ratio aircraft structures two methods are presented for the analysis of complex low  aspect ratio aircraft structures both methods provide for arbitrary external loading are general with respect to the orientation of structural members and permit arbitrary boundary conditions for purposes of analysis a structure is idealized as a network of flexural members with interconnected torsion boxes in the first method sets of linear equations are obtained by expressing boundary conditions member deflection equations equilibrium requirements and slope compatibility relationships in terms of deflections and internal forces the solution for deflections and internal forces is then formed as the product of an inverse structural matrix and a column matrix of load functions in the second method the conditions at a given boundary are assembled as a column matrix and are transferred in a step by step fashion over the entire structure to an opposite boundary the transfer is accomplished by successive multiplications of square matrices composed independently for the different transfer ranges the final operation is the inversion of a relatively small matrix and provides the solution for the unknown boundary conditions comparisons of theoretical results with experimental data and electric analog solutions are favorable
CRAN	supersonic flow at the surface of a circular cone at angle of attack supersonic flow at the surface of a circular cone at angle of attack formulas for the inviscid flow properties on the surface of a cone at angle of attack are derived for use in conjunction with the m i t cone tables these formulas are based upon an entropy distribution on the cone surface which is uniform and equal to that of the shocked fluid in the windward meridian plane they predict values for the flow variables which may differ significantly from the corresponding values obtained directly from the cone tables the differences in the magnitudes of the flow variables computed by the two methods tend to increase with increasing free stream mach number cone angle and angle of attack
CRAN	temperature and velocity profiles in the compressible laminar boundary layer with arbitrary distribution of surface temperature temperature and velocity profiles in the compressible laminar boundary layer with arbitrary distribution of surface temperature an analysis is presented which enables the temperature profiles veiocity profiles heat transfer and skin friction to be calculated for laminar flow over a two dimensional or axially symmetric surface without pressure gradient but with an arbitrary analytic distribution of surface temperature the general theory is applicable to a gas of any prandtl number although the numerical results given herein have been computed for air the predictions of the theory for the special case of constant surface temperature are compared with the calculations of crocco on the basis of this comparison it is inferred that the present theory enables heat transfer and skin friction calculations accurate to within about 5 per cent to be made for flight conditions up to mach numbers near 5 and to within about 1 or 2 per cent for supersonic wind tunnel conditions up to considerably higher mach numbers a particular effort has been made to present the results which are simple considering their generality in a form that can be used readily in practical applications from the mathematical point of view the theory is applicable to an arbitrary analytic distribution of surface temperature but in any given practical case it is necessary that the surface temperature distribution be approximated by a polynomial the only unknowns in the final equations developed are the coefficients of this polynomial so that the work involved in applying the theory in any given case depends entirely on the work involved in approximating a given surface  temperature distribution by a polynomial an example is worked out in detail which illustrates some of the principal effects of variable surface temperature it is shown that both positively infinite and negatively infinite heat transfer coefficients can occur the anomaly of infinite and negative heat transfer coefficients is discussed and attributed to the customary definition of the heat transfer coefficient which is shown to be fundamentally inappropriate for flows with variable surface temperature in the particular example considered a conventional method for calculating the net heat transferred yields completely incorrect results a brief qualitative discussion of the possible effects of the heat transfer on flow separation is given in order to facilitate the use of the results all of the principal equations developed are collected and summarized in the section entitled practical use of results
CRAN	investigation of laminar boundary layer in compressible fluids using the crocco method investigation of laminar boundary layer in compressible fluids using the crocco method in the present investigation of the flow of air in a thin laminar boundary layer on a flat plate the crocco method has been used to solve the simultaneous differential equations of momentum and energy involved in such flow the crocco method was used because it gave accurate results for arbitrary prandtl number near unity the prandtl number was taken at 0 75 the specific heat was held constant and the sutherland law of viscosity temperature variation was assumed to represent the viscosity data starting with an initial ambient temperature of  67 6 f the main results presented here are the skin friction and heat transfer coefficients as functions of reynolds number mach number and wall to free stream temperature ratio variations of shear velocity temperature and mach number across the boundary layer are included the crocco method is discussed in detail
CRAN	theory of aircraft structural models subjected to aerodynamic heating and external loads theory of aircraft structural models subjected to aerodynamic heating and external loads the problem of investigating the simultaneous effects of transient aerodynamic heating and external loads on aircraft structures for the purpose of determining the ability of the structure to withstand flight to supersonic speeds is studied by dimensional analyses it is shown that constructed of the same materials as the aircraft will be thermally similar to the aircraft with respect to the flow of heat through the structure will be similar to those of the aircraft when the structural model is constructed at the same temperature as the aircraft external loads will be similar to those of the aircraft subjected to heating and cooling that correctly simulate the aerodynamic heating of the aircraft except with respect to angular velocities and angular accelerations without requiring determination of the heat flux at each point on the surface and its variation with time acting on the aerodynamically heated structural model to those acting on the aircraft is determined for the case of zero angular velocity and zero angular acceleration so that the structural model may be subjected to the external loads required for simultaneous simulation of stresses and deformations due to external loads
CRAN	procedure for calculating flutter at high supersonic speed including camber deflections and comparison with experimental results procedure for calculating flutter at high supersonic speed including camber deflections and comparison with experimental results a method which may be used at high supersonic mach numbers is described for calculating the flutter speed of wings having camber in their deflection modes the normal coupled vibration modes of the wing are used to derive the equations of motion chord deflections of the vibration modes are approximated by polynomials the wing may have a control surface and may carry external stores although no aerodynamic forces on the stores are presented the aerodynamic forces that are assumed to be acting on the wing are obtained from piston theory and also from a quasi steady form of a theory for two dimensional steady flow airfoil shape and thickness effects are taken account of in the analysis the method is used to calculate the flutter speed of some wings which had been previously tested at mach numbers of 1 3 to 3 0 comparison of the calculations and experiment is made for flat plate 60 and 45 delta wings and also for an untapered 45 sweptback wing
CRAN	transition reynolds numbers of separated flows at supersonic speeds transition reynolds numbers of separated flows at supersonic speeds experimental research has been conducted on the effects of wall cooling mach number and unit reynolds number on the transition reynolds number of cylindrical separated boundary layers on an ogive cylinder model results were obtained from pressure and temperature measurements and shadowgraph observations the maximum scope of measurements encompassed mach numbers between 2 06 and 4 24 reynolds numbers based on length of separation between 60 000 and 400 000 and ratios of wall temperature to adiabatic wall temperature between 0 35 and 1 0 within the range of the present tests the transition reynolds number was observed to decrease with increasing wall cooling increase with increasing mach number and increase with increasing unit reynolds number the wall cooling effect was found to be four times as great when the attached boundary layer upstream of separation was cooled in conjunction with cooling of the separated boundary layer as when only the separated boundary layer was cooled wall cooling of both the attached and separated flow regions also caused in some cases reattachment in the otherwise separated region cavity resonance present in the separated region for some model configurations was accompanied by a large decrease in transition reynolds number at the lower test mach numbers
CRAN	method for calculation of compressible laminar boundary layer characteristics in axial pressure gradient with zero heat transfer method for calculation of compressible laminar boundary layer characteristics in axial pressure gradient with zero heat transfer the karman pohlhausen method is extended primarily to sixth degree velocity profiles for determining the characteristics of the compressible laminar boundary layer over an adiabatic wall in the presence of an axial pressure gradient it is assumed that the prandtl number is unity and that the coefficient of viscosity varies linearly with the temperature a general approximate solution which permits a rapid determination of the boundary layer characteristics for any given free stream mach number and given velocity distribution at the outer edge of the boundary layer is obtained numerical examples indicate that this solution will in practice lead to results of satisfactory accuracy including the critical reynolds number for stability for the special purpose of calculating the location of the separation point in an adverse pressure gradient a short and simple method based on the use of a seventh degree velocity profile is derived the numerical example given here indicates that this method should in practice lead to sufficiently accurate results for the special case of flow near a forward stagnation point it is shown that the karman pohlhausen method with the usual fourth degree profiles leads to results of adequate accuracy even for the critical reynolds number
CRAN	separation stability and other properties of compressible laminar boundary layer with pressure gradient and heat transfer separation stability and other properties of compressible laminar boundary layer with pressure gradient and heat transfer a theoretical study is made of the effect of pressure gradient wall temperature and mach number on laminar boundary layer characteristics and in particular on the skin friction and heat transfer coefficients on the separation point in an adverse pressure gradient on the wall temperature required for complete stabilization of the laminar boundary layer and on the minimum critical reynolds number for laminar stability the prandtl number is assumed to be unity and the coefficient of viscosity is assumed to be proportional to the temperature with a factor arising from the sutherland relation a simple and accurate method of locating the separation point in a compressible flow with heat transfer is developed numerical examples to illustrate the results in detail are given throughout
CRAN	an analysis of the applicability of the hypersonic similarity law to the study of the flow about bodies of revolution at zero angle of attack an analysis of the applicability of the hypersonic similarity law to the study of the flow about bodies of revolution at zero angle of attack the hypersonic similarity law as derived by tsien has been investigated by comparing the pressure distributions along bodies of revolution at zero angle of attack in making these comparisons particular attention was given to determining the limits of mach number and fineness ratio for which the similarity law applies for the purpose of this investigation pressure distributions determined by the method of characteristics for ogive cylinders for values of mach numbers and fineness ratios varying from 1 5 to 12 were compared pressures on various cones and on cone cylinders were also compared in this study the pressure distributions presented demonstrate that the hypersonic similarity law is applicable over a wider range of values of mach numbers and fineness ratios than might be expected from the assumptions made in the derivation this is significant since within the range of applicability of the law a single pressure distribution exists for all similarly shaped bodies for which the ratio of free stream mach number to fineness ratio is constant charts are presented for rapid determination of pressure distributions over ogive cylinders for any combination of mach number and fineness ratio within defined limits
CRAN	applicability of the hypersonic similarity rule to pressure distributions which include the effects of rotation for bodies of revolution at zero angle of attack applicability of the hypersonic similarity rule to pressure distributions which include the effects of rotation for bodies of revolution at zero angle of attack the analysis of technical note 2250 1950 is extended to include the effects of flow rotation it is found that the theoretical pressure distributions over ogive cylinders can be related by the hypersonic similarity rule with sufficient accuracy for most engineering purposes the error introduced into pressure distributions and drag of ogive cylinders by ignoring the rotation term in the characteristic equations is investigated it is found that the influence of the rotation term on pressure distribution and drag depends only upon the similarity parameter k mach number divided by fineness ratio although the error in drag due to neglect of the rotation term is negligible at k 0 5 the error is about 30 percent at k 2 0 charts are presented for the rapid determination of pressure distributions for rotational flow over ogive cylinders for all values of the similarity parameter between 0 5 and of mach number and fineness ratio
CRAN	pressure measurements on sharp and blunt 5 and 15 half angle cones at mach number 3 86 and angles of attack to 100 pressure measurements on sharp and blunt 5 and 15 half angle cones at mach number 3 86 and angles of attack to 100 measured pressure distributions on cones are compared with modified newtonian theory deviations as large as 14 percent of the stagnation pressure behind a normal shock are found by combining empirical results for cylinders normal to the flow with newtonian concepts a method of calculating pressures on cones at high angles of attack is developed calculations by this method differ from the experimental results on sharp cones by only 2 percent of the stagnation pressure behind a normal shock for blunted cones additional deviations up to 8 percent are noted near the nose schlieren pictures of the flow show an attached shock on the sharp of attack detachment of the shock appears to be associated with the attainment of sonic speed immediately behind the shock an orifice size effect is found which can increase the indicated pressure above the true value if the orifice width is greater than one tenth the local radius of curvature
CRAN	tables of exact laminar boundary layer solutions when the wall is porous and fluid properties are variable tables of exact laminar boundary layer solutions when the wall is porous and fluid properties are variable the three partial differential equations of the laminar boundary layer for two dimensional steady state compressible flow have been transformed into two ordinary differential equations by the method of pohlhausen falkner and skan the ordinary equations include parameters for expressing the simultaneous effects of pressure gradient in the main stream flow through a porous wall and property changes in the fluid due to large temperature differences between the wall and the free stream a total of 58 cases have been solved numerically by the method of picard the euler number nondimensional pressure gradient parameter ranges in value from 1 stagnation point value to the negative values found at the laminar separation points three rates of flow through the porous wall were considered including the impermeable case where the flow rate is 0 five temperature ratios stream temperature divided by wall temperature were used the uncooled and unheated case temperature ratio of 1 two cooled cases temperature ratios of ture ratios of and velocity weight flow and temperature distributions are tabulated as are the dimensionless stream function of falkner and skan and its derivatives and the dimensionless temperature function of pohlhausen and its derivatives for each case displacement momentum and convection thicknesses as well as nusselt number and coefficient of friction at the wall were computed
CRAN	estimation forces and moments due to rolling for several slender tail configurations at supersonic speeds estimation forces and moments due to rolling for several slender tail configurations at supersonic speeds the velocity potentials span loadings and corresponding force and moment derivatives have been theoretically evaluated for a number of slender tail arrangements performing a steady rolling motion at supersonic speeds the method of analysis is based upon an application of conformal transformation techniques the utilization of these techniques allows the simple determination of the complex potentials for various types of two dimensional boundary value problems in addition two simple and often used approximations to the rolling derivatives have been compared with the corresponding exact values determined by the method presented in this report in order to show the importance of wing tail interference the effect of the flow field behind a rolling wing on the tail characteristics has been illustrated for a simple wing tail arrangement
CRAN	on flow of electrically conducting fluids over a flat plate in the presence of a transverse magnetic field on flow of electrically conducting fluids over a flat plate in the presence of a transverse magnetic field the use of a magnetic field to control the motion of electrically conducting fluids is studied the boundary layer solutions are found for flow over a flat plate when the magnetic field is fixed relative to the plate or to the fluid the equations are integrated numerically for the effect of the transverse magnetic field on the velocity and temperature profiles and hence the skin friction and rate of heat transfer it is concluded that the skin friction and the heat transfer rate are reduced when the transverse magnetic field is fixed relative to the plate and increased when fixed relative to the fluid the total drag is increased in all the cases studied
CRAN	similar solutions for the compressible laminar boundary layer with heat transfer and pressure gradient similar solutions for the compressible laminar boundary layer with heat transfer and pressure gradient stewartsons transformation is applied to the laminar compressible boundary layer equations and the requirement of similarity is introduced resulting in a set of ordinary nonlinear differential equations previously quoted by stewartson but unsolved the requirements of the system are prandtl number of 1 0 linear viscosity temperature relation across the boundary layer an isothermal surface and the particular distributions of free stream velocity consistent with similar solutions this system admits axial pressure gradients of arbitrary magnitude heat flux normal to the surface and arbitrary mach numbers the system of differential equations is transformed to an integral system with the velocity ratio as the independent variable for this system solutions are found for pressure gradients varying from that causing separation to the infinitely favorable gradient and for wall temperatures from absolute zero to twice the free stream stagnation temperature some solutions for separated flows are also presented for favorable pressure gradients the solutions are unique for adverse pressure gradients where the solutions are not unique two solutions of the infinite family of possible solutions are identified as essentially viscid at the outer edge of the boundary layer and the remainder essentially inviscid for the case of favorable pressure gradients with heated walls the velocity within a portion of the boundary layer is shown to exceed the local external velocity the variation of a reynolds analogy parameter which indicates the ratio of skin friction to heat transfer is from zero to 7 4 for a surface of temperature twice the free stream stagnation temperature and from zero to 2 8 for a surface held at absolute zero where the value 2 applies to a flat plate
CRAN	hypersonic viscous flow over slender cones hypersonic viscous flow over slender cones viscous self induced pressures on 3  semivertex angle cones were measured over the range 3 7 free stream mach number 5 8 and 0 5 viscous interaction parameter 2 3 the data were found to be in good agreement with results obtained by talbot on 5 cones in the range rameter 3 5 all these data were correlated reasonably well by the viscous interaction parameter which is defined as where and are the mach number and reynolds number based on ideal taylor maccoll flow conditions and c is the chapman rubesin factor a new method for calculating self induced pressures is presented which takes into account the interaction between boundary layer growth and the inviscid flow field at the outer edge of the boundary layer pressures calculated by this method were only 10 to 20 percent higher than the measured values
CRAN	unsteady oblique interaction of a shock wave with plane disturbances unsteady oblique interaction of a shock wave with plane disturbances analysis is made of the flow field produced by oblique impingement of weak plane disturbances of arbitrary profile on a plane normal shock three types of disturbance are considered moves the sound wave refracts either as a simple isentropic sound wave or as an attenuating isentropic pressure wave depending on the angle between the shock and the incident sound wave a stationary vorticity wave of constant pressure appears behind the shock reflects as a sound wave and a stationary vorticity wave is produced the shock the incident wave refracts as a stationary vorticity wave and either a sound wave or attenuating pressure wave is also produced computations are presented for the first two types of incident wave over the range of incidence angles for shock mach numbers of 1 1 5 and
CRAN	convection of a pattern of vorticity through a shock wave convection of a pattern of vorticity through a shock wave an arbitrary weak spatial distribution of vorticity can be represented in terms of plane sinusoidal shear waves of all orientations and wave lengths fourier integral the analysis treats the passage of a single representative weak shear wave through a plane shock and shows refraction and modification of the shear wave with simultaneous generation of an acoustically intense sound wave applications to turbulence and to noise in supersonic wind tunnels are indicated
CRAN	some effects of joint conductivity on the temperature and thermal stresses in aerodynamically heated skin stiffener combinations some effects of joint conductivity on the temperature and thermal stresses in aerodynamically heated skin stiffener combinations temperatures and thermal stresses in typical skin stiffener combinations of winglike structures subjected to aerodynamic heating have been obtained with the aid of an electronic differential analyzer variations were made in an aerodynamic heat transfer parameter in a joint conductivity parameter and in the ratio of skin width to skin thickness the results which are presented in nondimensional form indicate that decreasing the joint conductivity parameter lowers both the interior and the average temperature ratios increases the peak thermal stress ratios in the skin and may considerably increase the peak stiffener stress ratios increasing the aerodynamic heat transfer parameter decreases the interior and average temperature ratios increases the peak skin stress ratios somewhat but greatly increases the peak stiffener stress ratios and increasing the ratio of skin width to skin thickness produces only moderate decreases in the peak skin stress ratios while moderately increasing the peak stiffener stress ratios
CRAN	dynamic stability of vehicles traversing ascending or descending paths through the atmosphere dynamic stability of vehicles traversing ascending or descending paths through the atmosphere an analysis is given of the oscillatory motions of vehicles which traverse ascending and descending paths through the atmosphere at high speed the specific case of a skip path is examined in detail and this leads to a form of solution for the oscillatory motion which should recur over any trajectory the distinguishing feature of this form is the appearance of the bessel rather than the trigonometric function as the characteristic mode of oscillation
CRAN	some aspects of air helium simulation and hypersonic approximations some aspects of air helium simulation and hypersonic approximations some illustrations of the differences that may be expected between results obtained in hypersonic wind tunnels that employ air and results obtained in those that employ helium as the test medium imperfect gas effects are not considered are compiled and presented herein simple expressions are presented that demonstrate the possibility of simulating air results in helium tests and of transforming helium data to equivalent air data nonviscous and viscous simulations are considered in most cases the methods and the general forms of the expressions for simulation that are derived are applicable to any two ideal gases having different ratios of specific heats
CRAN	predicted shock envelopes about two types of vehicles at large angles of attack predicted shock envelopes about two types of vehicles at large angles of attack methods based on oblique  and normal shock relationships and the continuity of mass flow through suitably chosen volume elements between the shock and body were developed to predict shock envelopes about two types of vehicles being considered for atmosphere entry one type is a high drag capsule shape the other type is essentially a slender triangular wing capable of providing high lift or high drag depending on the angle of attack predicted and measured shock envelopes were compared for a mach number range of 3 to 15 for vehicles at high angles of attack good agreement was found most of the available experimental data were in a speed and temperature range in which no important real gas effects occurred
CRAN	a study of flow changes associated with airfoil section drag rise at supercritical speeds a study of flow changes associated with airfoil section drag rise at supercritical speeds a study of experimental pressure distributions and section characteristics for several moderately thick airfoil sections was made a correlation appears to exist between the drag divergence mach number and the free stream mach number for which sonic velocity occurs at the airfoil crest the chordwise station at which the airfoil surface is tangent to the free stream direction it was found that since the mach number for which sonic velocity occurs at the airfoil crest can be estimated satisfactorily by means of the prandtl glauert rule a method is provided whereby the drag divergence mach number of an airfoil section at a given angle of attack can be estimated from the low speed pressure distribution and the airfoil profile this method was used to predict with a reasonable degree of accuracy the drag divergence mach number of a considerable number of airfoil sections having diverse shapes and a wide range of thickness chord ratios the pressure distributions and section force characteristics of several moderately thick airfoil sections at mach numbers above the drag divergence mach number were analyzed some of the characteristics of the flow over these airfoils at supercritical mach numbers are discussed
CRAN	laminar boundary layer behind shock advancing into stationary fluid laminar boundary layer behind shock advancing into stationary fluid a study was made of the laminar compressible boundary layer induced by a shock wave advancing into a stationary fluid bounded by a wall for weak shock waves the boundary layer is identical with that which occurs when an infinite wall is impulsively set into uniform motion shocks velocity and temperature profiles recovery factors and skin friction and heat transfer coefficients are tabulated for a wide range of shock strengths
CRAN	boundary layer behind shock or thin expansion wave moving into stationary fluid boundary layer behind shock or thin expansion wave moving into stationary fluid the boundary layer behind a shock or thin expansion wave advancing into a stationary fluid has been determined laminar and turbulent boundary layers were considered the wall surface temperature behind the wave was also investigated the assumption of a thin expansion wave is valid for weak expansions but becomes progressively less accurate for strong expansion waves the laminar boundary layer problem was solved by numerical integration except for the weak wave case which can be solved analytically integral karman pohlhausen type solutions were also obtained to provide a guide for determining expressions which accurately represent the numerical data analytical expressions for various boundary layer parameters are presented which agree with the numerical integrations within 1 percent the turbulent boundary layer problem was solved using integral methods similar to those employed for the solution of turbulent compressible flow over a semi infinite flat plate the fluid velocity relative to the wall was assumed to have a seventh power profile the blasius equation relating turbulent skin friction and boundary layer thickness was utilized in a form which accounted for compressibility consideration of the heat transfer to the wall permitted the wall surface temperature behind the wave to be determined the wall thickness was assumed to be greater than the wall thermal boundary layer thickness it was found that the wall temperature was uniform as a function of distance behind the wave for the laminar boundary layer case but varied with distance for the turbulent boundary layer case
CRAN	investigation of the stability of the laminar boundary layer in a compressible fluid investigation of the stability of the laminar boundary layer in a compressible fluid in the present report the stability of two dimensional laminar flows of a gas is investigated by the method of small perturbations the chief emphasis is placed on the case of the laminar boundary layer part 1 of the present report deals with the general mathematical theory the general equations governing one normal mode of the small velocity and temperature disturbances are derived and studied in great detail it is found that for reynolds numbers of the order of those encountered in most aerodynamic problems the temperature disturbances have only a negligible effect on those particular velocity solutions which depend primarily on the viscosity coefficient viscous solutions indeed the latter are actually of the same form in the compressible fluid as in the incompressible fluid at least to the first approximation because of this fact the mathematical analysis is greatly simplified the final equation determining the characteristic values of the stability problem depends on the inviscid solutions and the function of tietjens in a manner very similar to the case of the incompressible fluid the second viscosity coefficient and the coefficient of heat conductivity do not enter the problem only the ordinary coefficient of viscosity near the solid surface is involved part 2 deals with the limiting case of infinite reynolds numbers the study of energy relations is very much emphasized it is shown that the disturbance will gain energy from the main flow if the gradient of the product of mean density and mean vorticity near the solid surface has a sign opposite to that near the outer edge of the boundary layer a general stability criterion has been obtained in terms of the gradient of the product of density and vorticity analogous to the rayleigh tollmien criterion for the case of an incompressible fluid if this gradient vanishes for some value of the velocity ratio of the main flow exceeding 1 1 m where m is the free stream mach number
CRAN	an experimental study of the turbulen coundary layer on a shock tube wall an experimental study of the turbulen coundary layer on a shock tube wall interferometric measurements were made of the density profiles of an unsteady turbulent boundary layer on the flat wall of a shock tube the investigation included both subsonic and supersonic flow mach numbers of 0 50 and 1 77 with no pressure gradient and with heat transfer to a cold wall velocity profiles and average skin friction coefficients were calculated effects on the velocity profile of surface roughness and flow length are examined
CRAN	studies of structural failure due to acoustic loading studies of structural failure due to acoustic loading some discussion of the acoustic fatigue problem of aircraft structures is given along with data pertaining to the acoustic inputs from some powerplants in common use comparisons are given for results of some fatigue tests of flat panels and cantilever beams exposed to both random  and discrete type inputs in this regard it appears that both the stress level of the test and the type of model are significant hence no generalization can be made at this time with regard to increasing the fatigue life it was noted that increased stiffening of a panel due to curvature and pressure differential is particularly beneficial
CRAN	flight measurement of wall pressure fluctuations and boundary layer turbulence flight measurement of wall pressure fluctuations and boundary layer turbulence the results are presented for a flight test program using a fighter type jet aircraft flying at pressure altitudes of 10 000 20 000 and apparatus was used to measure and record the output of microphones and hot wire anemometers mounted on the forward fuselage section and wing of the airplane mean velocity profiles in the boundary layers were obtained from total pressure measurements the ratio of the root mean square fluctuating wall pressure to the free stream dynamic pressure is presented as a function of reynolds number and mach number the longitudinal component of the turbulent velocity fluctuations was measured and the turbulence intensity profiles are presented for the wing and forward fuselage section in general the results are in agreement with wind tunnel measurements which have been reported in the literature for example the variation of is the root mean square of the wall pressure fluctuation and q is the free stream dynamic pressure with reynolds number was found to be essentially constant for the forward fuselage section boundary layer while variations at the wing station were probably unduly affected by the microphone diameter which was large compared with the boundary layer thickness
CRAN	a comparative analysis of the performance of long range hypervelocity vehicles a comparative analysis of the performance of long range hypervelocity vehicles long range hypervelocity vehicles are studied in terms of their motion in powered flight and their motion and aerodynamic heating in unpowered flight powered flight is analyzed for an idealized propulsion system which rather closely approaches present day rocket motors unpowered flight is characterized by a return to earth along a ballistic skip or glide trajectory only those trajectories are treated which yield the maximum range for a given velocity at the end of powered flight aerodynamic heating is treated in a manner similar to that employed previously by the senior authors in studying ballistic missiles naca tn 4047 with the exception that radiant as well as convective heat transfer is considered in connection with glide and skip vehicles the ballistic vehicle is found to be the least efficient of the several types studied in the sense that it generally requires the highest velocity at the end of powered flight in order to attain a given range this disadvantage may be offset however by reducing convective heat transfer to the re entry body through the artifice of increasing pressure drag in relation to friction drag   that is by using a blunt body thus the kinetic energy required by the vehicle at the end of powered flight may be reduced by minimizing the mass of coolant material involved the glide vehicle developing lift drag ratios in the neighborhood of and greater than 4 is far superior to the ballistic vehicle in ability to convert velocity into range it has the disadvantage of having far more heat convected to it however it has the compensating advantage that this heat can in the main be radiated back to the atmosphere consequently the mass of coolant material may be kept relatively low the skip vehicle developing lift drag ratios from about 1 to 4 is found to be superior to comparable ballistic and glide vehicles in converting velocity into range at lift drag ratios below 1 it is found to be about equal to comparable ballistic vehicles while at lift drag ratios
CRAN	an analytical treatment of aircraft propeller precession instability an analytical treatment of aircraft propeller precession instability an analytical investigation is made of a precession type instability which can occur in a flexibly supported aircraft engine propeller combination by means of an idealized mathematical model which is comprised of a rigid power plant system flexibly mounted in pitch and yaw to a fixed backup structure the conditions required for neutral stability are determined the paper also examines the sensitivity of the stability boundaries to changes in such parameters as stiffness damping and asymmetries in the engine mount propeller speed airspeed mach number propeller thrust and location of pitch and yaw axes stability is found to depend strongly on the damping and stiffness in the system with the use of nondimensional charts theoretical stability boundaries are compared with experimental results obtained in wind tunnel tests of an aeroelastic airplane model in general the theoretical results which do not account for wing response show the same trends as observed experimentally however for a given set of conditions calculated airspeeds for neutral stability are consistently lower than the measured values evidently this result is due to the fact that wing response tends to add damping to the system
CRAN	effects of extreme surface cooling on boundary layer transition effects of extreme surface cooling on boundary layer transition an investigation was made to determine the combined effects of surface cooling pressure gradients nose blunting and surface finish on boundary layer transition data were obtained for various body shapes at a mach number of 3 12 and reynolds numbers per foot as high as 15x10 previous transition studies with moderate cooling have shown agreement with the predictions of stability theory for surface roughnesses ranging from 4 to 1250 microinches the location of transition was unaffected with moderate cooling with extreme cooling an adverse effect was observed for each of the parameters investigated in general the transition reynolds number decreased with decreasing surface temperature in particular the beneficial effects of a favorable pressure gradient obtained with moderate cooling disappear with extreme cooling and a transition reynolds number lower than that observed on a cone is obtained further an increase in the nose bluntness decreased the transition reynolds number under conditions of extreme cooling
CRAN	effect of distributed three dimensional roughness and surface cooling on boundary layer transition and lateral spread of turbulence at supersonic speeds effect of distributed three dimensional roughness and surface cooling on boundary layer transition and lateral spread of turbulence at supersonic speeds an investigation was made in the langley 4 by 4 foot supersonic pressure tunnel at mach numbers of 1 61 and 2 01 to determine 1 the effect of distributed roughness on boundary layer transition with the model surface at adiabatic wall temperature and cooled and 2 the effect of surface cooling on the lateral spread of turbulence both distributed granular type and single spherical roughness particles were used and transition of the boundary layer was determined by hot wire anemometers the transition triggering mechanism of the three dimensional roughness at supersonic speeds appeared to be the same as that previously observed at subsonic speeds in fact the critical value of the roughness reynolds number parameter that is the value at which turbulent spots are initiated by the roughness was found to be approximately the same at supersonic and subsonic speeds when complete local conditions at the top of the roughness including density and viscosity were considered in the formulation of the roughness reynolds number for three dimensional roughness at a reynolds number less than its critical value the roughness introduced no disturbances of sufficient magnitude to influence transition surface cooling although providing a theoretical increase in stability to small disturbances did not increase to any important extent the value of the critical roughness reynolds number for three dimensional roughness particles cooling therefore because of its effect on the boundary layer thickness density and viscosity actually promoted transition due to existing three dimensional surface roughness for given mach and reynolds numbers the measured lateral spread of turbulence in the boundary layer appeared to be unaffected by the increased laminar stability derived from the surface cooling
CRAN	compressible laminar flow and heat transfer about a rotating isothermal disk compressible laminar flow and heat transfer about a rotating isothermal disk the flow and heat transfer about a rotating isothermal disk are re examined to include the effects of compressibility and property variations if viscous dissipation is neglected the compressible problem is correlated to the incompressible problem by assuming linear variations of viscosity and thermal conductivity with temperature certain inaccuracies in several previous incompressible solutions are noted and corrected herein the effect of compressibility appears as a distortion of the normal coordinate and normal velocity component and as a multiplicative factor in the heat transfer coefficient the nusselt number and in the expressions for the skin friction components and torque required to rotate the disk
CRAN	theoretical investigation of the ablation of a glass type heat protection shield of varied material properties at the stagnation point of a re entering irbm theoretical investigation of the ablation of a glass type heat protection shield of varied material properties at the stagnation point of a re entering irbm the melting type heat protection at the stagnation point of a re entering irbm is treated by employing homogeneous opaque and nondecomposing glass shields which do not exceed a temperature of some effects due to variations of the glass properties the ballistic re entry vehicle has a nose diameter of 0 635 m a ballistic factor of 3 5 x 10 a re entry angle of 124 9 from the vertical at an altitude of 100 km and a re entry speed of 4 5 the performance of 36 different glass shields with assumed combinations of material properties is investigated by employing a calculation method which yields practically exact transient solutions for the problem as a corollary results for a certain steady flight state are also given the discussions made it possible to derive under realistic flight conditions some thermal characteristics for the employment of thin or light weight glass shields investigation of these hypothetical glass shields leads to the conclusion that a low thermal conductivity and a high specific heat and thus a small thermal diffusivity are most desirable a small thermal diffusivity yields high surface temperatures causing a high radiative heat transfer out of the shield and steep temperature profiles normal to the surface causing a small thermal penetration across the shield with little total ablation of the shield results show that for the assumed irbm re entry the necessary thickness of the employed glass shields increases monotonically with thermal diffusivity which is the only material parameter affecting this thickness a high viscosity level and a high emissivity constant of the surface of the supposedly opaque shield are also desirable although these two properties exert a comparatively small influence on the overall performance when disregarding glass shields with an extremely low viscosity level
CRAN	discussion of solar proton events and manned space flights discussion of solar proton events and manned space flights as a result of studies made during the international geophysical year igy and the international geophysical cooperation igc it is known that a considerable fraction of large solar flares give rise to almost pure streams of protons which reach the earth and continue to arrive for as long as 11 days the energies of these particles lie within a very steep spectrum extending from 20 to least 500 mev because of the frequency of large flares during times of high solar activity and owing to the long duration of each solar proton emission these particles were present in detectable intensity near the top of the earths atmosphere for about 15 percent of the time from 1957 to 1960 the number of large flares that accelerated and released these particles during this three year period was about 30 the event that began on august 22 1958 contributed greatly toward the understanding of the solar and terrestrial sequence of events and in addition provided the first identification of the emitted particles a flare on may of protons in the neighborhood of the earth that this phenomenon was recognized as an additional radiation hazard to manned vehicles in the high atmosphere and in most parts of the solar system the three very intense events that occurred in july 1959 further supported this conclusion and the possibility of predicting such events became an important consideration in addition to its value in the protection of human beings effective forecasting clearly would be of great value in the detailed scientific study of this phenomenon this paper presents a preliminary discussion of some aspects of predicting the arrival of protons at the earth following the appearance of solar activity features and equally important of forecasting the periods when this penetrating radiation is unlikely to occur
CRAN	experimental investigation of the downstream influence of stagnation point mass transfer experimental investigation of the downstream influence of stagnation point mass transfer this report presents the results of an experimental investigation of the downstream influence of localized mass transfer in the stagnation region of a blunt body under hypersonic flow conditions the coolant is injected through a porous plug coaxial with the centerline of symmetry of the model the tests were carried out in a wind tunnel with a mach number of 6 0 stagnation temperatures of approximately 1 600 r and a stagnation pressure of approximately 600 psia four different gases were injected over a range of mass flows the heat transfer on the impermeable section was measured under isothermal wall conditions for the higher rates of mass flow adiabatic surface temperatures were also determined the theoretical analysis of the boundary layer flow is investigated in order to establish the similarity parameters for the flow system these parameters permit the extrapolation of the test results to other flow conditions provided that laminar flow prevails helium is found to be the most efficacious coolant
CRAN	on trails of axisymmetric hypersonic blunt bodies flying through the atmosphere on trails of axisymmetric hypersonic blunt bodies flying through the atmosphere the trail left in the atmosphere by a body moving at hypersonic speeds is the subject of theoretical treatment the times required for ionization and dissociation and their inverse processes to go to completion when compared to the flow times of a gas particle are important in determining the observable effects of hypersonic trails i e emitted thermal radiation and reflection of electromagnetic waves from the trail in order to simplify the theoretical treatment the trail is divided into two regions 1 the expansion controlled trail which treats the behavior of the wake behind the body up to a point along the direction of flight where the pressure decays to the free stream value and cooling is controlled principally by the expansion of the flow and 2 the conduction controlled trail where the trail cools mainly by diffusion of heat away from the high temperature core the influence of the details of the body shape on the observables are discussed and a simple computational procedure for the behavior of the conduction controlled trail is developed based on integral methods results of calculations that assume thermodynamic equilibrium of the flow field give the values of the thermodynamic variables in the trail of a sphere axial distributions of emitted thermal radiation and maps of electron density distribution it is shown that the cooling of the conduction controlled trail is essentially due to conduction of heat and that viscous effects are not important it is found that this portion of the trail does not widen as one proceeds downstream flight velocities considered vary between 15 000 and 35 000 ft sec and altitudes range between 100 000 and 250 000 ft
CRAN	inviscid incompressible flow theory of static peripheral jets in proximity to the ground inviscid incompressible flow theory of static peripheral jets in proximity to the ground an exact flow theory of peripheral jets issuing symmetrically from a hovering aerial ground vehicle is presented the theory is exact insofar as no simplifying assumptions have been made in obtaining a solution of the governing inviscid two dimensional hydrodynamical flow equations the results are valid for all jet thickness vehicle height ratios the limit of applicability of existing theories very low thickness height ratios are defined jet reaction lift and power coefficients for static conditions are introduced and computed lift augmentation and lift power ratios are also calculated applications to three dimensional vehicles with rotational symmetry are indicated
CRAN	free convection magnetohydrodynamic flow past a porous flat plate free convection magnetohydrodynamic flow past a porous flat plate the incompressible flow of an electrically conducting fluid past a porous plate with constant suction velocity in the presence of a transverse uniform strength has recently been investigated by gupta in this note the problem is generalized to take into account the effect of free convection when a body force is acting parallel to the wall the fluid is assumed to be semi incompressible as usual in addition to the obvious practical significance this problem is also interesting in the sense that it provides another exact solution of the magnetohydrodynamic equations since the only electromagnetic assumptions involved are constant properties and freedom from excessive charges
CRAN	magnetohydrodynamic free convection pipe flow magnetohydrodynamic free convection pipe flow it has been shown that transverse magnetic fields of practical strengths exert considerable influence on liquid metal free convection vertical flat plate and parallel plate flow fields the extent of influence was determined by the magnitude of a nondimensional parameter a which is the ratio of the hartmann number to the fourth root of the grashof number and is a measure of the relative influence of the magnetic and buoyant forces in this note the steady fully developed laminar free convection flow of a fluid of electrical conductivity through a fully submerged open ended constant temperature vertical pipe located in a transverse magnetic field of strength is analyzed in terms of the same parameter the magnitude of its influence on the velocity and temperature profiles the surface shear and heat transfer and the volumetric flow rate is determined
CRAN	an investigation of separated flows part i the pressure field an investigation of separated flows part i the pressure field the present article describes an investigation of several types of separated regions such as blunt base wakes and cavities formed in cutouts in the boundaries and ahead of or behind two dimensional steps in supersonic mach numbers 2 to 4 and subsonic flow the conditions for the existence the geometry and the pressure field are described in this paper a second article to be published will describe investigations of the internal flow and the heat transfer across such separated regions it is found that there is a maximum critical ratio of the length of the separated free shear layer to the depth of the depression in the boundary beyond which the cavity collapses leaving mutually independent separated regions at each protrusion this critical length changes greatly upon laminar turbulent transition in the oncoming boundary layer in either laminar or turbulent flow it is approximately independent of mach and reynolds numbers a semiempirical correlation predicting the conditions under which the flow will span a depression of arbitrary depth is proposed detailed pressure distributions along the boundaries of a cavity in turbulent flow are presented as a function of the ratio of the cavity length to the critical length which is found to be the pertinent similarity parameter for short notches the impact pressure due to the reversal of the inner portion of the shear layer at recompression tends to thicken the shear layer and a type of boundary layer free stream interaction governs the pressure field the pressure in the cavity is nearly constant and can be higher than free stream in long notches the shear layer bends inward at separation and curves back gradually ahead of the recompression point the floor pressure variation is pronounced and the recovery pressure at reattachment is small the variation of the drag coefficient with mach number reflects the change from one to the other mechanism of recompression detailed surveys of the mach number distributions in a blunt body wake and the mixing region behind its throat as well as in the shear layer spanning a cutout in a wall are presented and analyzed it is found that in general the assumptions of the simple supersonic wake models which rely on a principle of steady flow with mass conservation in the cavity are not adequate for cavities in which there is recompression against a boundary results showing the influence of the thickness of the initial boundary layer in the range of 0 3 to 3 times the notch depth and of the geometry of the notch are also presented
CRAN	periodic temperature distributions in a two layer composite slab periodic temperature distributions in a two layer composite slab an investigation to determine the feasibility of using an insulating thermal barrier to protect exposed solid propellant motors from atmospheric or environmental temperature variations has recently been completed in one portion of this study a solution was developed for the periodic temperature distribution in a two layer composite slab one exposed surface of this composite slab was adiabatic and the other exposed surface was subjected to a sinusoidal temperature variation the technique used in the analysis was similar to that of grober in this note pertinent features of the development of the solution are given
CRAN	periodic temperature distribution in a two layer composite slab periodic temperature distribution in a two layer composite slab in a recent contribution to the readers forum under the above title stonecypher outlined a method for finding the periodic temperature distribution in a two layer composite slab one exposed surface of the slab being insulated and the other subject to a sinusoidal temperature variation perfect thermal contact between the two layers and constant thermal properties were assumed two years ago i drew attention in these pages to a method for determining the transient temperature in such a two layer slab resulting from a triangular heat input pulse i should like to point out that this same method also is applicable to the case where one external face is given a sinusoidal temperature variation with time the method is based on the analogy between one dimensional heat flow and the flow of an electric current in a simple transmission line having only series resistance and parallel capacitance
CRAN	the analysis of redundant structures by the use of high speed digital computers the analysis of redundant structures by the use of high speed digital computers large scale redundant structure analyses are currently feasible by the use of modern high speed digital computers this capability opportunely meets the urgent need to solve complex problems which otherwise would be hopelessly beyond the capacity of the hand desk computer however the difficulties have now shifted from tedious hand computations to the problems of adequately representing the structure by a model and of the peculiarities of irregular geometrical configurations a wide scope of problem types can be handled by a generalized program approach matrix formulation is used for the organization of input data and for handling data transfer in the large complex of subroutines including the formation of equilibrium and continuity conditions to the final loads and deflections simultaneous treatment of thermal expansions and plasticity is included the use of minimum size redundant systems is emphasized starting from the philosophy of cutting members to provide a statically determinate structure improved numerical accuracy and problem size capacity is gained for a given computer examples are discussed ranging from simple plane load diffusion problems to pressurized fuselage cutouts and complex wing fuselage shell intersection type problems
CRAN	the supersonic blunt body problem   review and extensions the supersonic blunt body problem   review and extensions a survey of existing analytical treatments of the supersonic or hypersonic blunt body problem indicates that none is adequate for predicting the details of the flow field reasons are given for the failure of various plausible approximations a numerical method which is simpler than others proposed is set forth for solving the full inviscid equations using a medium sized electronic computer results are shown from a number of solutions for bodies that support detached shock waves described by conic sections
CRAN	the transverse curvature effect in compressible axially symmetric laminar boundary layer flow the transverse curvature effect in compressible axially symmetric laminar boundary layer flow the viscous transverse curvature effect in compressible axially symmetric laminar boundary layer flow has been investigated and it is found that the effect is characterized by the parameter which is essentially the ratio of the boundary layer thickness to body radius it is shown that the busemann and crocco integrals of the two dimensional energy equation for are still valid for axially symmetric flow in which the transverse curvature effects are considered by a generalization of manglers transformation it is then shown that the boundary layer equations are reducible to an almost two dimensional form making the analysis simpler for two asymptotic flow regions characterized by and less than or of the order of unity it is with the latter region that the present paper is primarily concerned and for this case it is shown that the additional term in the momentum and energy equations which differentiates them from the two dimensional form behaves like an external favorable pressure gradient except for certain special cases it is necessary to obtain the of the order of unity by means of asymptotic expansions in ascending powers of a parameter that is small compared to unity but proportional to it is shown how the asymptotic solutions can be found for 1 the velocity and temperature distributions for the compressible zero pressure gradient case when the body shapes are given by and and 2 the velocity distribution for incompressible flow with an external velocity of the form past a body given by the zeroth approximation is the mangler result for the cases of a linear external velocity distribution similar profiles can be found for all values of more generally it is shown that similar profiles exist if the exponents n and m satisfy the condition that here similar is used in the restricted meaning that the distributions are derivable from ordinary differential equations in the case of the cone and cylinder with zero pressure gradient where the equations have been numerically integrated for the first order correction to the mangler formulation shows that the effect on both the skin friction coefficient and heat transfer rate can become appreciable in the range where is less than or of the order of unity at a constant the effects are increased in magnitude when either the ratio of wall to free stream temperature or mach number is increased also all other conditions being equal for the same value of the skin friction coefficient and heat transfer increase on the cylinder is greater than that on the cone for flows with pressure gradient the transverse curvature term behaves again like a favorable pressure gradient and tends to delay both separation and transition when compared with axially symmetric flows in which the transverse curvature effect is neglected
CRAN	temperature distribution and thermal stresses in a model of a supersonic wing temperature distribution and thermal stresses in a model of a supersonic wing the transient temperature distribution and the thermal stresses in an idealized wing structure considered by hoff and torda in reference 1 are determined only the effects of aerodynamic heating and of heat conduction are included radiation and convection effects are neglected the present work differs from that of reference 1 in that the conduction from the cap to the web is considered when the temperature of the cap is calculated and the spar cap temperature is assumed to be a function of both space and time graphs of temperature and thermal stress distributions are presented and the results are compared with those of reference 1
CRAN	review of published data on the effect of roughness on transition from laminar to turbulent flow review of published data on the effect of roughness on transition from laminar to turbulent flow a review is presented of the published data on the effect of roughness especially single roughness elements on transition from laminar to turbulent flow in which an attempt is made to reanalyze and correlate the available information the reanalysis shows that the transition reynolds number of a flat plate with zero pressure gradient is a function of the ratio of the height of the roughness element to the displacement thickness of the boundary layer at the element this functional relation being a better representation of the data than a constant critical reynolds number of the roughness element other data show that the effects of roghness are similar in streams of different initial turbulence and that a plot of the ratio of transition reynolds number of the rough plate to that for the smooth plate against the ratio of the height of the roughness element to displacement thickness of the boundary layer at the element gives good correlation of all the data for a given shape when transition occurs downstream from the roughness element at a certain value of the height thickness ratio dependent on the stream speed location of roughness element and airstream turbulence the transition position reaches the element and remains there as the height or the stream speed is further increased the paper also discusses available data on the effect of distributed roughness on transition on a flat plate as well as some of the published data on roughness effects on transition on air foils
CRAN	a mixing theory for the interaction between dissipative flows and nearly isentropic streams a mixing theory for the interaction between dissipative flows and nearly isentropic streams by means of a simplified theoretical model the present paper treats the general class of flow problems characterized by the interaction between a viscous or dissipative flow near the surface of a solid body or in its wake and an outer nearly isentropic stream for the present the external flow is taken to be a plane steady supersonic flow which makes a small angle with a plane surface or plane of symmetry although the methods used can be extended to curved surfaces to axially symmetric supersonic flows and also to subsonic flows the internal dissipative flow is regarded as quasi one dimensional and parallel to the surface on the average with a properly defined mean velocity and mean temperature the nonuniformity of the actual velocity distribution is taken into account only approximately by means of a relation between mean temperature and mean velocity mixing or the transport of momentum from outer stream to dissipative flow is considered to be the fundamental physical process determining the pressure rise that can be supported by the flow with the aid of this concept a large number of flow problems is shown to be basically similar such as boundary layer shockwave interaction wake flow behind blunt based bodies base pressure problem flow separation in overexpanded supersonic nozzles separation on wings and bodies etc
CRAN	heat transfer by laminar flow to a rotating plate heat transfer by laminar flow to a rotating plate an exact solution of the heat transfer problem for the von karman example of the laminar flow of a viscous fluid over a rotating plate is given in dimensionless form and physically discussed the solution is explicitly given for a constant temperature on the plate with viscous dissipation included the numerical results are given for prandtl numbers from 0 5 to 10
CRAN	the fundamentals of the statistical theory of turbulence the fundamentals of the statistical theory of turbulence statistical theory in general considers mean values of certain quantities in the case of the turbulent motion one is interested in mean values of velocities and of their derivatives and in mean values of squares and products of velocities and their derivatives it was o reynolds who first expressed the so called apparent or turbulent stresses by the mean values of the products of the velocity components the different theories suggested so far have as their common objective the establishment of relations between certain mean values e g between the turbulent shear stresses given by the mean products of velocity fluctuations and the derivatives of the mean velocities i e the measured mean velocity gradients in this sort of investigations the conception of the correlation is of paramount importance the late a friedman tried to introduce the correlations as unknown variables in the hydrodynamic equations however he could not carry his investigations to practical results i e to results which can be compared with the experimental evidence recently g i taylor had success in his analysis of isotropic turbulence by means of correlation calculations and was able to discuss theoretically the problem of the decay of turbulence in a windstream behind a turbulence producing device his theory raised considerable interest because it is concerned with the important problem of wind tunnel turbulence and its results could be compared directly with experimental work done by dryden in this country and by fage townend and simmons in england the present paper is concerned with two fundamental problems with uniform isotropic turbulence and with the turbulent friction in a parallel stream first the general theory of isotropic turbulence is developed this general theory includes taylors consideration as a special case however it
CRAN	vibration isolation of aircraft power plants vibration isolation of aircraft power plants vibration in aircraft structure can almost always be traced to vibratory forces originating from the power plant these forces are transmitted to the aircraft in two ways 1 by the action of air forces upon the surfaces of the aircraft in or adjacent to the slip stream of the propeller and 2 by direct transmission of unbalanced forces from the power plant through the engine mounting the latter has always caused the preponderance of disturbance vibratory stresses induced in the engine mounting structure occasionally produce fatigue failures in the associated parts and always shorten the useful life of the entire aircraft structure more important however are the psychological and physiological effects of continuous vibration and its attendant noise on the passengers and crew this may very likely be the major source of the rapid fatigue which is so intimately associated with flying the importance and desirability of drastically reducing vibration can hardly be questioned this paper is limited to a consideration of the directly transmitted forces and further considers the power plants as rigid bodies attached by flexible means to the aircraft which is also considered as a rigid body of relatively large mass it is also limited to the case of engines and engine supporting structures having axial symmetry radial engines although the methods employed could easily be extended to other cases
CRAN	laminar heat transfer over blunt nosed bodies at hypersonic flight speeds laminar heat transfer over blunt nosed bodies at hypersonic flight speeds this paper deals with two limiting cases of laminar heat transfer over blunt nosed bodies at hypersonic flight speeds or high stagnation temperatures a thermodynamic equilibrium in which the chemical reaction rates are regarded as very fast compared to the rates of diffusion across streamlines b diffusion as rate governing in which the volume recombination rates within the boundary layer are very slow compared to diffusion across streamlines in either case the gas density near the surface of a blunt nosed body is much higher than the density just outside the boundary layer and the velocity and stagnation enthalpy profiles are much less sensitive to pressure gradient than in the more familiar case of moderate temperature differences in fact in case a the nondimensionalized enthalpy gradient at the surface is represented very accurately by the classical zero pressure gradient value and the surface heat transfer rate distribution is obtained directly in terms of the surface pressure distribution in order to illustrate the method this solution is applied to the special cases of an unyawed hemisphere and an unyawed blunt cone capped by a spherical segment in the opposite limiting case where diffusion is rate controlling the diffusion equation for each species is reduced to the same form as the low speed energy equation except that the prandtl number is replaced by the schmidt number the simplifications introduced in case a are also applicable here and the expression for surface heat transfer rate is similar the maximum value of the ratio between the rate of heat transfer by diffusion alone and by heat conduction alone in the case of thermodynamic equilibrium is given by prandtl no schmidt no when the diffusion coefficient is estimated by taking a reasonable value of atom molecule collision cross section this ratio is 1 30 additional theoretical and especially experimental studies are clearly required before these simple results are accepted
CRAN	advantages and limitations of models advantages and limitations of models summary the use of models for structural test investigations in the presence of kinetic heating effects is examined the principal features of the complex process to be represented are discussed under the classifications external air flow internal heat transfer elastic response of these the second is found to influence most model design and an analysis of a typical structure is included to illustrate the various contributions to internal heat transfer
CRAN	theory of mixing and chemical reaction in the opposed jet diffusion flame theory of mixing and chemical reaction in the opposed jet diffusion flame an idealization of the flow system used by potter and butler is analyzed the differential equation of mixing is solved exactly to give the location of and burning rate in the flame the solutions to the chemical kinetic differential equation are discussed relations being derived between the jet flow rate at extinction the chemical kinetic constants and the laminar flame speed in premixed gases it is shown that the jet flow rate at extinction is independent of the transport properties comparison is made with the experimental data of potter heimel and butler it is argued that experiments must be carried out at higher reynolds numbers if the measurements are to be quantitatively analyzable
CRAN	similar solutions of a free convection boundary layer equation for an electrically conducting fluid similar solutions of a free convection boundary layer equation for an electrically conducting fluid author investigates the existence of a class of similar solutions for free convection from a vertical flat plate such as are known for free convection in a nonconducting fluid the magnetic field acts transversely to the fluid motion and is assumed to remain constant in the direction perpendicular to the plate this introduces into the momentum equation a retarding force which is a function only of x the distance along the plate length for similarity it is found that the magnetic inductance must vary as if the plate temperature is constant if n 0 the magnetic inductance is constant while the plate temperature increases linearly with x
CRAN	the asymptotic boundary layer on a circular cylinder in axial incompressible flow the asymptotic boundary layer on a circular cylinder in axial incompressible flow in this paper the incompressible boundary layer over a circular cylinder in an axial flow is investigated far from the leading edge if u and v are the velocity components in the x and r direction respectively and a stream function is introduced by and then for a constant free stream velocity has the following asymptotic form where the ps are determined successively first for s 1 and all t then s 2 and all t etc from ordinary differential equations here and log c eulers constant it is shown that the effect of the curvature of the body in planes perpendicular to the flow is to increase the skin friction also the case in which the free stream velocity is proportional to at the method breaks down is studied it is concluded that the effect of the curvature of the cylinder when the boundary layer has a thickness comparable with its radius of curvature is to delay separation
CRAN	the transverse potential flow past a body of revolution the transverse potential flow past a body of revolution it is shown that in the potential flow of an incompressible inviscid fluid past a body of revolution set with its axis at right angles to the stream the velocity components at the surface along and perpendicular to the meridians vary with azimuthal angle round the body in a simple manner this is shown by entirely elementary considerations
CRAN	on the mixing of two parallel streams on the mixing of two parallel streams using the techniques of boundary layer theory the proper third boundary condition for the mixing of two parallel streams is derived from the compatibility condition of the higher order approximation it is shown that the commonly adopted third boundary condition of balancing of transverse momentum is correct only for the mixing problem of two semi infinite incompressible streams for the fulfillment of the proper third boundary condition the possibility of introducing the similar solution of blasius type is examined for various cases
CRAN	properties of the confluent hypergeometric function properties of the confluent hypergeometric function the confluent hypergeometric functions have proved useful in many branches of physics they have been used in such problems involving diffusion and sedimentation as isotope separation and protein molecular weight determinations in the ultracentrifuge the solution of the equation for the velocity distribution of electrons in high frequency gas discharges may frequently be expressed in terms of these functions the high frequency breakdown electric field may then be predicted theoretically for gases by the use of such solutions together with kinetic theory this report presents some of the properties of the confluent hypergeometric functions together with six figure tables of the functions
CRAN	the production of uniform shear flow in a wind tunnel the production of uniform shear flow in a wind tunnel a nearly uniform shear flow was obtained in the working section of a wind tunnel by inserting a grid of parallel rods with varying spacing the function of such a grid is to impose a resistance to the flow so graded across the working section as to produce a linear variation in the total pressure at large distances downstream without introducing an appreciable gradient in static pressure near the grid a method of calculating a suitable arrangement of the rods is described although this method is strictly applicable only to weakly sheared flows an experiment made with a grid designed for a shear parameter as large as 0 45 gave results in close agreement with the theory there was no evidence from the experiment of any large scale secondary flow accompanying the shear  a danger inherent in an empirical attempt to grade the resistance of the grid  nor was any tendency observed for the shear to decay with increasing distance from the grid
CRAN	dynamics of a dissociating gas dynamics of a dissociating gas this is a lucid introduction to the effects of dissociation in gas dynamics the problem in view is that of air flow past a bluff body at speeds somewhat above 2 km sec thermodynamic equilibrium is assumed theories of near equilibrium for transport properties and of large departures from equilibrium being promised in parts 2 and 3 following a survey of the equilibrium statistical thermodynamics of a pure dissociating diatomic gas a new model is introduced this ideal dissociating gas is characterized by only three constants the characteristic temperature density and internal energy for dissociation physically it may be regarded as having its vibrational modes always just half excited so that at low temperatures the ratio of specific heats approaches 4 3 rather then 7 5 thermodynamic properties of the ideal gas are derived and the oblique shock wave relations deduced in the strong shock approximation including an elegant relation between the principal curvatures of any bow shock and the subsequent vorticity useful relations are given for the isentropic changes that take place along streamlines between shocks various of these results are applied to the problem typified by a sphere flying at high mach number the newtonian impact theory and its empirical modification are dismissed as lacking theoretical basis in favor of the limit for large values of both mach number and density ratio across the shock it is suggested that the zero surface pressure sometimes predicted by the latter theory corresponds to separation not of the flow but of the shock wave from the surface an estimate is given for the subsequent shape of the shock finally another approximation is applied to the region near the stagnation streamline the fluid is assumed incompressible but rotational in accord with the shock relations and it is shown that a spherical shock corresponds to a concentric spherical body the resulting surface pressure is within 1 per cent of that predicted by freemans second approximation based on the newtonian plus centrifugal solution same j 1 1956
CRAN	the laminar boundary layer equation a method of solution by means of an automatic computer the laminar boundary layer equation a method of solution by means of an automatic computer a method very suitable for use with an automatic computer of solving the hartree womersley approximation to the incompressible boundary layer equation is developed it is based on an iterative process and the choleski method of solving a simultaneous set of linear algebraic equations the programming of this method for an automatic computer is discussed tables of a solution of the boundary layer equation in a region upstream of the separation point are given in the upstream neighbourhood of separation this solution is compared with goldsteins asymptotic solution and the agreement is good
CRAN	steady motion of conducting fluids in pipes under transverse magnetic fields steady motion of conducting fluids in pipes under transverse magnetic fields this paper studies the steady motion of an electrically conducting viscous fluid along channels in the presence of an imposed transverse magnetic field when the walls do not conduct currents the equations which determine the velocity profile induced currents and field are derived and solved exactly in the case of a rectangular channel when the imposed field is sufficiently strong the velocity profile is found to degenerate into a core of uniform flow surrounded by boundary layers on each wall the layers on the walls parallel to the imposed field are of a novel character an analogous degenerate solution for channels of any symmetrical shape is developed the predicted pressure gradients for given volumes of flow at various field strengths are finally compared with experimental results for square and circular pipes
CRAN	acoustical signal detection in turbulent airflow acoustical signal detection in turbulent airflow improvement in detected signal to noise ratio is obtained for a periodic signal masked by additive noise and turbulent noise backgrounds comparisons are made between autocorrelation crosscorrelation and a combination of frequency filtering and crosscorrelation although the latter method provided the greatest improvement the crosscorrelation technique was the most successful single method it turned out that the maximum improvement obtainable was limited by the dynamic range of the correlator computer and not by errors due to finite averaging time and scanning the delay the improvement for signals masked by turbulent noise was found to be about 5 db less than that obtained for additive noise
CRAN	response of plates to a decaying and convecting randon pressure field response of plates to a decaying and convecting randon pressure field following the methods of lyon an analysis of the vibratory response of a plate to a random pressure field is given the pressure correlation of the random field is assumed to have a scale small compared to the plate size to decay exponentially and to convect with constant speed over the plate two cases are considered one in which the convection speed is much less than the speed of free flexural waves in the plate the other in which the convection speed is the same order as the flexural wave speed the mean square plate displacement is shown to be relatively independent of convection for speeds much less than the flexural wave speed and to increase significantly for speeds in the order of the flexural wave speed it is shown that damping is usually but not always an effective means of vibration reduction in the case of convection speeds much smaller than the flexural speed the use of hysteretic damping for reduction of the displacement response is shown to be limited by the decay of the assumed random pressure field
CRAN	on turbulent lubrication on turbulent lubrication the paper concerns the hydrodynamic turbulent motion in the lubricant layer proceeding from the reynolds equations and introducing the approximations currently used in lubrication problems owing to the lubricant film thickness the general motion equations for turbulent lubrication are written using the prandtl mixing length hypothesis exact and approximate solutions are obtained for the velocity distribution into the lubricant layer the results are discussed by pointing out the pressure gradient and the reynolds number influence on the velocity distributions as well as the differences with respect to the laminar flow in order to obtain simple formulae the exact dependence of the rate of flow on the pressure gradient into a dimensionless form is replaced by a linear relation the slope of which depends on the reynolds number this approximation allows the obtainment of the pressure differential equation under a simple form the pressure equation is integrated in case of journal bearings by assuming a constant or a variable viscosity of the lubricant the results are compared to the experimental data obtained by m i smith and d d fuller and the good qualitative agreement is pointed out
CRAN	the elliptic cylinder in a shear flow with hyperbolic velocity profile the elliptic cylinder in a shear flow with hyperbolic velocity profile the stream function for the shear flow with hyperbolic velocity profile past an elliptic cylinder has been determined as an infinite series of mathieu functions it is found that the stagnation streamline of the flow is displaced towards a region of higher velocity this displacement increasing the main stream 2 as the stream becomes progressively non uniform 3 with increase of minor axis length when the major axis length remains invariant in each case the displacement reaches a limiting value as the cylinder moves away from the axis of symmetry of the stream these limiting values are reached at critical distances from the axis of symmetry which decrease as the stream becomes progressively non uniform but these distances are approximately independent of incidence the pressure coefficients and the resultant force and moment coefficients associated with the cylinder have also been obtained and investigated numerically for the flat plate type of cylinder
CRAN	the motion of a viscous liquid past a paraboloid the motion of a viscous liquid past a paraboloid an approximate solution for the steady flow of incompressible viscous liquid past a paraboloid of revolution is described an assumption is made for the form of the stokes stream function and substituted into the navier stokes equations using paraboloidal coordinates after making suitable approximations a non linear differential equation for a function f is deduced the solutions of this equation depend on the reynolds number of the flow considered examples found by numerical integration are given to illustrate the properties of the function f for reynolds numbers varying from 0 0001 to is found and it is shown that this approximate solution tends to the perfect fluid flow away from the boundary allowance being made for the displacement effect of what may be called the boundary layer
CRAN	the transonic flow of a compressible fluid through an axially symmetrical nozzle the transonic flow of a compressible fluid through an axially symmetrical nozzle by a method similar to that developed by s tomotika and k tamada quart appl math 7 381 397 1950 these rev 11 275 for computing two dimensional mixed isentropic flows in the sonic region the flow in the vicinity of the throat of an axially symmetrical nozzle is studied several exact solutions to von karmans equation for axially symmetrical transonic flows are obtained and the one that gives flows through a converging and diverging nozzle is considered in detail this solution consists of four branches of which two are rejected because of singularities of the remaining two branches one gives pure supersonic flow and the other gives taylors type of flow with a local supersonic region in the throat by varying a parameter the latter branch approaches two asymptotes which yield meyers type of asymmetrical flows
CRAN	conduction of fluctuating heat flow in a wall consisting of many layers conduction of fluctuating heat flow in a wall consisting of many layers van gorcum has pointed to interesting and important analogies between the theory of a passive four pole and the conduction of heat waves through stratiform bodies this paper generalizes in certain regards van gorcums ideas and draws their consequences for the case of a solid bounded by two infinite parallel planes and consisting of any number of layers made from different materials
CRAN	measurement of convective heat transfer by means of the reynolds analogy measurement of convective heat transfer by means of the reynolds analogy prestons method for measuring skin friction in pipes has been extended to include non uniform flow with and without pressure gradients over flat surfaces by means of a modified form of the reynolds analogy the local convective heat transfer coefficient can be related to the skin friction and it is proposed that the method be used in aerodynamic models of furnaces and in heat transfer plant of simple geometry more investigations are required of the effects of fluid turbulence surface roughness and surface curvature on convective heat transfer and skin friction
CRAN	a theory for base pressures in transonic and supersonic flow a theory for base pressures in transonic and supersonic flow a physical flow model is devised based on the concepts of interaction between the dissipative shear flow and the adjacent free stream and the conservation of mass in the wake four flow components are integrated in the model namely the flow approaching the trailing edge the expansion around the trailing edge the mixing within the free jet boundary and the recompression at the end of the wake a unique and stable solution results for the base pressure theoretical results obtained for thin approaching boundary layer do not require empirical information and are therefore best suited to evaluate the merits of the theory here emphasized is the case of isoenergetic constant pressure mixing in the turbulent free jet boundary and agreement is found between theory and experimental data
CRAN	a simplified approximate method for the calculation of the pressure around conical bodies of arbitrary shape in supersonic and hypersonic flow a simplified approximate method for the calculation of the pressure around conical bodies of arbitrary shape in supersonic and hypersonic flow exact conical flow solutions are available only for circular cones at zero angle of attack for nonaxisymmetric cones or cones at angle of attack only approximate methods exist these methods are generally quite complicated and further limited to certain body shapes or certain mach number ranges a great need was therefore felt for a simple approximate method applicable to any arbitrarily shaped conical body at zero incidence as well as at angle of attack such a method has been developed recently at lockheed and is presented here in abbreviated form the method is based on the equivalent cone theory this theory determines the pressure on a conical body utilizing information for a symmetric cone at zero angle of attack with the same normal component of the free stream with respect to the surface as the local element of the body considered this method works relatively well at high mach numbers however it is quite inconsistent at lower mach numbers especially for bodies which deviate considerably from circular cones the equivalent cone method does not give satisfactory results mainly due to the fact that it considers only the local surface element on the body independent of the other body elements in the newtonian theory manner
CRAN	the downstream influence of mass transfer at the nose of a slender cone the downstream influence of mass transfer at the nose of a slender cone the influence of localized mass transfer at the nose of a slender cone under hypersonic flow conditions has been studied by experimental and theoretical means two gaseous coolants nitrogen and helium are injected through a porous plug subtending a half angle of 30 the effect of the mass transfer on the shock shape pressure distribution heat transfer and transition are investigated the experimental work involved tests in the mach number 8 0 tunnel at pibal the theoretical analysis involved a study of the effect of mass transfer on the shock stand off distance and leads to an inviscid flow parameter permitting the experimentally determined shock shape and pressure distribution to be extrapolated to other than test conditions and to other coolant gases there is obtained the maximum value of this parameter resulting in no significant alteration of the pressure distribution on the cone and thus defining the flows in which boundary layer type similarity applies significant reductions in heat transfer are obtained with injection indeed with small amounts of helium injection the peak heating is found to occur downstream on the cone and to be an order of magnitude less than would occur at the stagnation point without mass transfer with nitrogen early transition is found to occur so that local heating rates are actually increased over those prevailing at the same reynolds number without injection
CRAN	a summary of the supersonic pressure drag of bodies of revolution a summary of the supersonic pressure drag of bodies of revolution a number of approximate theories for supersonic and hypersonic flow over bodies of revolution at zero angle of attack are appraised by a critical comparison with characteristics and second order results with the use of hypersonic similarity as a basis for the comparison most of the approximate theories are inadequate except over very limited ranges of fineness ratio and mach number the combination of second order supersonic theory and second order shock expansion theory provides consistently good results throughout the supersonic speed range on the basis of exact or nearly exact supersonic solutions and a limited amount of test data and theory in the transonic region summary design curves are developed that give the pressure drag of conical and ogive noses and conical and ogive boattails over the complete range of transonic supersonic and hypersonic mach numbers other shapes can be analyzed in the same manner provided that an equivalent amount of data is available the analysis is made with the assumption of inviscid flow so that the effects of boundary layer growth shock boundary layer interaction and flow separation are not included the present correlations provide a sound basis of inviscid flow results from which these additional viscous effects can be evaluated
CRAN	measurements of skin friction of the compressible turbulent boundary layer on a cone with foreign gas injection measurements of skin friction of the compressible turbulent boundary layer on a cone with foreign gas injection measurements of average skin friction of the turbulent boundary layer have been made on a 15 total included angle cone with foreign gas injection measurements of total skin friction drag were obtained at free stream mach numbers of 0 3 0 7 3 5 and x 10 with injection of helium air and freon 12 through the porous wall substantial reductions in skin friction are realized with gas injection within the range of mach numbers of this test the relative reduction in skin friction is in accordance with theory  that is the light gases are most effective when compared on a mass flow basis there is a marked effect of mach number on the reduction of average skin friction this effect is not shown by the available theories limited transition location measurements indicate that the boundary layer does not fully trip with gas injection but that the transition point approaches a forward limit with increasing injection the variation of the skin friction coefficient for the lower injection rates with natural transition is dependent on the flow reynolds number and type of injected gas and at the high injection rates the skin friction is in fair agreement with the turbulent boundary layer results
CRAN	an investigation of two dimensional supersonic base pressures an investigation of two dimensional supersonic base pressures an investigation of the base pressure behind wedges at mach numbers 2 and 3 in the laminar and the transitional regime is reported temperature and velocity traverses through the mixing zone are shown and exploratory investigations of the wake vortex by use of hot wires and flow visualization techniques are described it is found that the laminar two dimensional base pressure agrees well with chapmans theoretical predictions the shear layer exhibits gross velocity distributions characteristic of the free jet mixing zone but also shows disturbances that originate in the expansion turning of the oncoming boundary layer an interesting trailing vortex is observed which is explained in terms of nonuniform mixing rate in the wake
CRAN	supersonic axially symmetric nozzles supersonic axially symmetric nozzles at each of twenty one exit mach numbers ranging from 1 008 to 8 238 ten supersonic axially symmetric nozzle shapes with plane sonic surfaces have been computed on the eniac by the method of characteristics the boundary of the shortest of each group of ten has a sharp edge at the sonic plane while the others have smooth boundaries this report describes the computational procedures and presents a sample of the results for twenty nozzles more extensive and elaborate tables of the results of the entire computations are available at the ballistic research laboratories nozzle contours can be obtained accurately from them by interpolation for exit mach numbers between 1 479 and 8 238 for a wide range of ratios of nozzle length to throat diameter
CRAN	effects of free stream vorticity on the behaviour of a viscous boundary layer effects of free stream vorticity on the behaviour of a viscous boundary layer theoretical investigation is considered of the two dimensional steady flow field at large distance from a finite object set in a viscous incompressible fluid study is made of coordinate type expansions for pressure and velocity for large r uniformly in for fixed reynolds number assuming exact boundary conditions at infinity and regularity of flow with zero net mass flow across a simple curve enclosing the object mathematical nature of the distinction between parameter and coordinate type expansions is discussed with description of inner and outer expansions and matching techniques a feature of the expansion procedure is the introduction of an artificial parameter inner and outer expansions are matched with the aid of known solutions of the navier stokes equations analysis requires simple consideration of the heat and laplace equations without resort to special methods paper is worth studying by those interested in asymptotic expansion procedures
CRAN	an investigation of the noise produced by a subsonic air jet an investigation of the noise produced by a subsonic air jet to investigate the theoretical predictions of lighthill on aerodynamic sound measurements have been made of the sound field of a 1 in air jet issuing from a long pipe the measurements have been made over a wide frequency band 30 to 10 000 cycles sec and in one third octave bands in this frequency range the mean mach number at the pipe orifice was varied from 0 3 to 1 0 the dependence of the apparent position of the noise sources on frequency and jet speed was investigated at a given frequency a source is situated farther from the jet orifice the higher the jet speed lower frequency sources appear farther downstream than ones of higher frequency consistent with their association with larger eddies the directional characteristics of the sound field at different frequencies and jet speeds are illustrated by means of scale diagrams showing lines of constant sound intensity these sound fields are analyzed in terms of the moving quadrupole sources of lighthills theory and good agreement obtained it is shown that the apparent spread of the sources at low frequencies is due to the doppler effect at low frequency relative to the frequency of maximum power output the radiation is predominantly that of three mutually orthogonal longitudinal quadrupoles which except for the effect of convection upon it has a sound field like a monopole source at higher frequencies the sound fields of lateral and longitudinal quadrupoles predominate
CRAN	the behaviour of non linear systems the behaviour of non linear systems many of the phenomena that occur in the world around us are governed by nonlinear relationships in the development of the mathematical sciences the difficulties of nonlinear analysis have hindered the formulation of nonlinear concepts that would permit us to understand such phenomena in the present article our progress in understanding the behavior of nonlinear systems is reviewed and an attempt is made to present the resulting concepts in such a way that they may be applied with some generality to other problems
CRAN	two dimensional jet mixing of a compressible fluid two dimensional jet mixing of a compressible fluid the mixing and divergence of a supersonic jet exhausting into a supersonic stream are investigated theoretically in the first part of this paper the flow is assumed to be laminar when the velocity and temperature in the jet are different slightly from those of the surrounding stream by the method of small perturbations and under ordinary boundary layer assumptions the equation of motion of two dimensional flow will be reduced to a form of the well known equation of heat conduction whose solution is known for any given boundary conditions it has also been shown that the exact solution of the two dimensional jet mixing of viscous compressible fluids can be obtained by successive approximations starting with the solution of small perturbations velocity and temperature distributions for two cases  one is the mixing of two uniform flows and the other is the mixing of a jet of compressible fluid from a two dimensional nozzle with full expansion exhausting into a supersonic stream  have been calculated the properties of the jet mixing depend mainly on the momentum of the jet regardless of whether the change of momentum is due to the change of velocity or the change of temperature  i e the change of density compressibility has a considerable effect on the properties of the jet in the second part the cases of turbulent flow are investigated by means of reichardts theory of free turbulence the turbulent shearing stress may be expressed as it has been shown in this paper that where is a constant that can be determined experimentally the value of n lies between 0 and 1 the exact value of n depends on the condition of mixing when the expression of turbulent shearing stress given above is used instead of the viscous stress in the equation of motion by suitable transformation of variables it has been shown that the equation of two dimensional turbulent jet mixing is identical to that of the laminar case hence the solution of the first part of this paper can be applied to the turbulent case provided that the characteristic constants and n have been properly chosen
CRAN	viscosity effects in sound waves of finite amplitude in survey in mechanics viscosity effects in sound waves of finite amplitude in survey in mechanics this article has as its subject the conflicting influence on sound propagation of convection on the one hand and of diffusion and relaxation on the other whose importance in the determination of the structure of shock waves was first appreciated clearly by sir geoffrey taylor as an essential introduction to the main topics author gives an exceptionally clear and valuable account of the physical mechanisms of viscosity thermal conductivity and other diffusion effects including relaxation the classical theory of shock wave formation is then discussed and some extensions are made the remainder of the article is based on the demonstration that the nonlinear equation for plane progressive sound waves in which convection and diffusion are taken into account to a first approximation can be transformed into burgerss equation the general solution of which was given by hopf and cole this approach in which all flows are continuous they become discontinuous at shock waves in the limit as viscosity etc tend to zero allows the author to re derive and extend whithams theory of the formation and decay of weak plane shock waves and to derive many new results such as the velocity distributions during the union of two shock waves and during the formation of a shock wave the application of the same idea to non plane shock waves is also discussed but more briefly in these cases burgerss equation is not quite such a good approximation as before the article concludes with sections on sound waves whose reynolds numbers based on the length scale of the flow and the velocity amplitude are comparable with unity and on the effects of relaxation on the properties of shock waves the whole is much more than a survey and represents a very substantial advance in the theory of sound waves it is the finest possible tribute to sir geoffrey taylor that he should be able to inspire articles such as this and the others in this volume
CRAN	some effects of surface curvature on laminar boundary layer flow some effects of surface curvature on laminar boundary layer flow the laminar flow of a viscous incompressible fluid over a two dimensional curved surface is investigated for two cases one in which the curvature is large and the other in which it is cases are obtained as approximations from the exact equations of motion by an order of magnitude analysis these equations are solved for flow over a particular surface with zero surface pressure gradient in this analysis the pressure gradient normal to the surface is included and the outer boundary conditions are modified in accordance with the requirements of flow over a curved surface the results indicate that for equal reynolds numbers the stress on convex surfaces is less than the flat plate value while the stress on concave surfaces is greater than for a flat plate the most important effect of surface curvature for the cases considered is the modification of the shape of the velocity profile near the outer edge of the boundary layer the requirement that a smooth transition exist between the viscous flow and the potential flow at the outer edge of the layer causes the profile to have a negative slope near the outer edge for convex surface curvature and a positive slope for concave surface curvature
CRAN	note on an interaction between the boundary layer and the inviscid flow note on an interaction between the boundary layer and the inviscid flow according to the classical boundary layer theory the flow about bodies at reynolds numbers of aeronautical interest can be considered as composed of two regimes an outside inviscid flow and a thin boundary layer region adjacent to the body this point of view leads to the approximation that on a slightly curved surface throughout the layer is negligibly small the additional assumption that the inviscid flow is irrotational leads to the requirement that is zero at the outer edge of the boundary layer in this theory any interaction between the two regimes is accountable by a simple correction to the body shape based on the boundary layer displacement thickness recently in connection with hypersonic laminar boundary layers this classical point of view has been modified an interaction between the two flow regimes leading to a self induced axial pressure gradient has been considered it is the purpose of the present note to point out another type of interaction which may be of practical importance and of fundamental interest even at mach numbers below those considered in the hypersonic boundary layer theory and which may have to be considered in that theory
CRAN	the calculation of wall shearing stress from heat transfer measurements in compressible flows the calculation of wall shearing stress from heat transfer measurements in compressible flows it has been shown by ludwieg that the wall shearing stress of a laminar or turbulent boundary layer in an incompressible flow can be determined from a heat transfer measurement at the surface the instrument used in that investigation was essentially a small locally insulated heating element embedded in the test surface the size of the instrument was restricted by the condition that the thermal boundary layer generated by the heating element be contained locally within the laminar sublayer in the present analysis ludweigs theory for such an instrument is extended to compressible flow over an insulated flat plate with the same limitations on the design and operation of the instrument as mentioned above it can also be assumed for compressible laminar and turbulent boundary layers that only the flow in the immediate vicinity of the wall or the laminar sublayer will be affected in the region of the heated element this assumption then permits the use of the laminar boundary layer equations as the governing equations for this analysis for both laminar and turbulent boundary layers
CRAN	recent developments in rocket nozzle configurations recent developments in rocket nozzle configurations existing configurations of supersonic portion of rocket nozzles are described and compared survey covers bell type conical and contoured nozzles annular nozzles plug nozzles and the authors own e d expansion deflection nozzle the latter is a bell type nozzle in which the gases are first deflected radially outward by a small central plug then expanded radially inward around the base of the plug and finally deflected back to a nearly axial direction by the nozzle wall in compressive turning
CRAN	the generation of sound by aerodynamic means the generation of sound by aerodynamic means a summary is given of some of the more important experimental results relating to the noise radiated from a cold subsonic turbulent jet these are then related to the predictions of lighthills general theory of aerodynamic noise
CRAN	wakes in axial compressors wakes in axial compressors the tendency in the past has been to assume that when wakes or non uniform total head profiles are fed into an axial compressor then substantially constant static pressure prevails at the entry the variations in total head appearing as variations in velocity this variation in velocity causes variation in incidence on the early stage blade rows and thus can give rise to excitation of blade vibration this assumption is implicit for instance in references 1 and 2 but we think has been a common assumption by most of the people working in this field where the compressor is fed by a duct of substantially parallel walls for a reasonable length ahead such an assumption appeared justifiable such a duct when given an air flow test with its outlet discharging for instance to atmosphere instead of to the compressor then the distribution assumed would normally be obtained and in fact many surveys of such ducts have been represented in this fashion the object of this note is to show that in fact this distribution will not normally occur when the compressor is present and we may normally expect much more nearly a constant velocity into the compressor with attendant static pressure distributions to match with the total head variations ahead of the intake with of course the attendant curved flow to support the static pressure gradients
CRAN	viscous effects on pitot tubes at low speeds viscous effects on pitot tubes at low speeds measurements were made of the pressure in a blunt nosed pitot tube in an air stream at reynolds numbers from about 15 to 1000 the results are expressed in terms of a pressure coefficient density of the fluid and p and v are the static pressure and velocity in the undisturbed stream as found in previous investigations becomes greater than 1 at low reynolds numbers the increase being about at a reynolds number of 50 based on external tube radius in disagreement with the work of hurd chesky and shapiro no decrease of below 1 was found at any reynolds number when the values of found by various experiments are plotted against reynolds numbers based on internal tube radius it is found that the curves are in closer agreement than when the external radius is used
CRAN	the determination of turbulent skin friction by means of pitot tubes the determination of turbulent skin friction by means of pitot tubes a simple method of determining local turbulent skin friction on a smooth surface has been developed which utilises a round pitot tube resting on the surface assuming the existence of a region near the surface in which conditions are functions only of the skin friction the relevant physical constants of the fluid and a suitable length a universal non dimensional relation is obtained for the difference between the total pressure recorded by the tube and the static pressure at the wall in terms of the skin friction this relation on this assumption is independent of the pressure gradient the truth and form of the relation were first established to a considerable degree of accuracy in a pipe using four geometrically similar round pitot tubes  the diameter being taken as representative length these four pitot tubes were then used to determine the local skin friction coefficient at three stations on a wind tunnel wall under varying conditions of pressure gradient at each station within the limits of experimental accuracy the deduced skin friction coefficient was found to be the same for each pitot tube thus confirming the basic assumption and leaving little doubt as to the correctness of the skin friction so found pitot traverses were then made in the pipe and in the boundary layer on the wind tunnel wall the results were plotted in two non dimensional forms on the basis already suggested and they fell close together in a region whose outer limit represented the breakdown of the basic assumption but close to the wall the results spread out due to the unknown displacement of the effective centre of a pitot tube near a wall this again provides further evidence of the existence of a region of local dynamical similarity and of the correctness of the skin friction deduced from measurements with round pitot tubes on the wind tunnel wall the extent of the region in which the local dynamical similarity may be expected to hold appears to vary from about to of the boundary layer thickness for conditions remote from and close to separation respectively
CRAN	free flight techniques for high speed aerodynamic research free flight techniques for high speed aerodynamic research the development rocket borne and rocket launched high speed airplane model test is described details of airborne components telemetering units tracking and their calibration are also discussed tests on controls drag measurements longitudinal stability evaluations lift measurements pressure measurements aeroelastic estimations and sonic bang recordings are effected the reynolds numbers involved are much higher than are usual in the wind tunnel and extensions of mach numbers are obtained beyond the tunnel limits both free of the tunnel wall interference
CRAN	the problem of aerodynamic heating the problem of aerodynamic heating paper is a good review of knowledge to date on convective heat transfer to objects moving through air at low and high speeds theoretical and experimental information is given on recovery factors and heat transfer coefficients for isothermal surfaces of unswept flat plates wedges and cones with attached shock waves and stagnation points of blunt bodies of revolution for both laminar and turbulent boundary layers a convenient nomograph for calculating flat plate turbulent boundary layer heat transfer coefficients is given effects of surface cooling surface roughness and supply stream turbulence on transition are discussed and shown graphically
CRAN	interplanetary orbits interplanetary orbits the basic equations under simplified conditions for interplanetary flight are derived for a voyage from planet to planet an unlimited number of orbits is possible in order to give a clear survey of these possible orbits a diagram is developed from which the approximate energy requirement the duration and other particulars of a voyage can be easily found
CRAN	heat flow in composite slabs heat flow in composite slabs this paper presents the solution of the heat flow problem in composite walls under heat transfer conditions which are typical of uncooled rocket engine walls analytic expressions in the form of fourier sums are obtained for the temperature distribution in a composite wall consisting of an inner refractory medium and an outer metallic medium under newtonian heat transfer into the first medium with negligible heat transfer from the second medium to the exterior the expressions obtained are based on a plane parallel composite slab as a representative model for relatively thin cylindrical walls with thickness to radius ratio not exceeding 0 2 the general results for the composite slab are simplified for the limiting cases of a thin refractory shield with a thick shielded medium and a thick refractory shield with a thin shielded medium
CRAN	skin friction in the laminar boundary layer in compressible flow skin friction in the laminar boundary layer in compressible flow from an analysis of the work of crocco and others semi empirical formulae are derived for the skin friction on a flat plate at zero incidence with a laminar boundary layer these formulae are for the general case of heat transfer and when there is no heat transfer the problem of heat transfer and the effect of radiation are discussed in the light of these formulae the second formula is then utilised in the development of an approximate method for solving the momentum equation of the boundary layer on a cylinder without heat transfer the method indicates that with increase of mach number there is a marked forward movement of separation from a flat plate in the presence of a constant adverse velocity gradient
CRAN	supersonic flow past slender bodies with discontinuous profile slope supersonic flow past slender bodies with discontinuous profile slope wards slender body theory is extended to derive first approximations to the external forces on slender bodies of general cross section with discontinuous profile slope two classes of body are considered bodies whose profile typified by the local radius is continuous between the nose and base and certain bodies whose profile is discontinuous such as bodies with annular or side air intakes and wing bodies on which the wing has an unswept leading edge where air intakes are concerned it is assumed that they are sharp edged and that there is no spillage of the internal flow the following conclusions apply to the former class of bodies the variation of drag with mach number is found to depend only on the discontinuities in the longitudinal rate of change of the cross sectional area and is thus independent of cross sectional shape the drag itself is unchanged if the direction of the flow is reversed the expressions for lift and moment assume the same forms as for smooth pointed bodies the lift depending only on conditions at the base of the body the general theory is applied to winged bodies of revolution with an unswept wing leading edge the results bear a marked resemblance to those obtained by ward the results for wings alone are seen to be applicable with one modification to subsonic as well as to supersonic speeds
CRAN	supersonic flow past slender pointed wings with similar cross sections at zero lift supersonic flow past slender pointed wings with similar cross sections at zero lift some recent theoretical work on slender pointed wings at zero lift is co ordinated and extended the wings considered may have any pointed plan form shape provided that the trailing edge is straight and unswept the root section profile and cross section shapes are arbitrary provided that on any one wing the latter are descriptively similar diamond or parabolic biconvex for instance though not necessarily geometrically similar the chief aim of the work is to find wings with simple geometry low wave drag and pressure distributions which are unlikely to be seriously affected by viscous effects wave drag and pressure distributions are calculated by slender wing theory general formulae which are both simple and instructive are given for the wave drag and the overall pressure distribution with particular emphasis on the root pressure distribution results for a number of wings of special interest are presented and discussed
CRAN	on displacement thickness on displacement thickness four alternative theoretical treatments of displacement thickness and generally of the influence of boundary layers and wakes on the flow outside them are set out first for two dimensional and then for three dimensional laminar or turbulent incompressible flow they may be called the methods of flow reduction equivalent sources velocity comparison and the principal expression obtained for the displacement thickness in three dimensional flow may be written if as orthogonal coordinates x y specifying position on the surface we choose x as the velocity potential of the external flow and y as a coordinate constant along the external flow streamlines such that h dy is the distance between x y and z is the distance from the surface u and v are the x and y components of velocity and u takes the value u just outside the boundary layer
CRAN	expansions at small reynolds number for the flow past a sphere and a circular cylinder expansions at small reynolds number for the flow past a sphere and a circular cylinder this paper is concerned with the problem of obtaining higher approximations to the flow past a sphere and a circular cylinder than those represented by the well known solutions of stokes and oseen since the perturbation theory arising from the consideration of small non zero reynolds numbers is a singular one the problem is largely that of devising suitable techniques for taking this singularity into account when expanding the solution for small reynolds numbers the technique adopted is as follows separate locally valid the regions close to and far from the obstacle reasons are presented for believing that these stokes and oseen expansions are respectively of the forms where are spherical or cylindrical polar coordinates made dimensionless with the radius of the obstacle r is the reynolds number and and vanish with r substitution of these expansions in the navier stokes equation then yields a set of differential equations for the coefficients and but only one set of physical boundary conditions is applicable to each expansion the no slip conditions for the stokes expansion and the uniform stream condition for the oseen expansion so that unique solutions cannot be derived immediately however the fact that the two expansions are in principle both derived from the same exact solution leads to a matching procedure which yields further boundary conditions for each expansion it is thus possible to determine alternately successive terms in each expansion the leading terms of the expansions are shown to be closely related to the original solutions of stokes and oseen and detailed results for some further terms are obtained
CRAN	integration of the boundary layer equations integration of the boundary layer equations the equations of the boundary layer are integrated by an expression of the form where f x is a positive function with x 0 as the stationary point x is slowly varying the integral contains an unknown parameter which is found from the condition the integral is evaluated by the method of steepest descent the expressions obtained are usually divergent except in few cases which include blasiuss equation the divergent expressions are summed by eulers transformation to check the procedure it is applied to falkner and skans equation the results obtained are very striking few terms in the expansions are sufficient to obtain close agreement with hartrees laborious numerical computations the method is also applied to the general boundary layer equation for the case of flow past an elliptic cylinder measured by schubauer the results obtained are in close agreement with schubauers measurements for the velocities almost up to separation for the position of the separation point and in satisfactory agreement downstream of separation
CRAN	the generation of noise by isotropic turbulence the generation of noise by isotropic turbulence a finite region with fixed boundaries of an infinite expanse of compressible fluid is in turbulent motion this motion generates noise and radiates it into the surrounding fluid the acoustic properties of the system are studied in the special case in which the turbulent region consists of decaying isotropic turbulence it is assumed that the reynolds number of the turbulence is large and that the mach number is small the noise appears to be generated mainly by those eddies of the turbulence whose contribution to the rate of dissipation of kinetic energy by viscosity is negligible it is shown that the intensity of sound at large distances from the turbulence is the same as that due to a volume distribution of simple acoustic sources occupying the turbulent region in this analogy the whole fluid is to be regarded as a stationary and uniform acoustic medium the local value of the acoustic power output p per mass of turbulent fluid is given approximately by the formula where a is a numerical constant u is the mean square velocity fluctuation is the time and c is the velocity of sound in the fluid the constant a is expressed in terms of the well known velocity correlation function f r by assuming the joint probability distribution of the turbulent velocities and their first two time derivatives at two points in space to be gaussian the numerical value is then obtained by substituting the form of f r corresponding to heisenbergs theoretical spectrum of isotropic turbulence it is found that the effects of decay make only a small contribution to the value of a and that the order of magnitude of a is not changed when widely differing forms of the function f r are used
CRAN	on the flow of compressible fluid past an obstacle on the flow of compressible fluid past an obstacle it is well known that according to classical hydrodynamics a steady stream of frictionless incompressible fluid exercises no resultant force upon an obstacle such as a rigid sphere immersed in it the development of a resistance is usually attributed to viscosity or when there is a sharp edge to the negative pressure which may accompany it helmholtz in either case it would seem that resistance involves something of the nature of a wake extending behind the obstacle to an infinite distance when the system of disturbed velocities although it may mathematically extend to infinity remains as it were attached to the obstacle there can be no resistance the absence of resistance is asserted for an incompressible fluid but it can hardly be supposed that a small degree of compressibility as in water would affect the conclusion on the other hand high relative velocities exceeding that of sound in the fluid must entirely alter the conditions it seems worth while to examine this question more closely especially as the first effects of compressibility are amenable to mathematical treatment
CRAN	on the steady motion of viscous incompressible fluids with particular reference to a variation principle on the steady motion of viscous incompressible fluids with particular reference to a variation principle except in exceptional cases it is not possible to represent the motion of a viscous incompressible liquid by means of a variation principle but all cases of such motion that have yet been discovered belong to this class of exceptional cases the appropriate functions are given
CRAN	velocity and temperature distributions in the turbulent wake behind a heated body of revolution velocity and temperature distributions in the turbulent wake behind a heated body of revolution recently see abstract 954 1938 goldstein made calculations based on theories of vorticity transfer of the distributions of velocity and temperature in the turbulent wake behind a heated body of revolution and the present authors now record an experimental determination of these distributions in a low turbulence wind tunnel difficulty was experienced in obtaining a truly symmetrical wake and observations have been reduced to mean values curves of which are given
CRAN	on the solution of the laminar boundary layer equations on the solution of the laminar boundary layer equations the problem of the flow along a flat plate placed edgewise to a steady stream when a retarding pressure gradient varying linearly as the distance x from the leading edge of the plate is superposed is discussed if y denotes distance measured perpendicular to the plate a solution is obtained in the form of a power series in x where coefficients are functions of differential equations are obtained for these coefficients seven of the coefficients have been obtained with reasonable accuracy and the eighth and ninth roughly unfortunately it appears that about eight more terms are required to carry the solution to the point of separation the work involved in their determination is prohibitive two approximate methods have been developed for determining the error when the first seven terms of the series are used as an approximation these methods lead to the determination of the point of separation and are in agreement as to its position if is the velocity at the edge of the boundary layer at the leading edge of the plate and is the velocity gradient separation is found when a method is developed for the solution of the boundary layer equations in any retarded region it is obtained by replacing the velocity distribution at the edge of the boundary layer by a circumscribing polygon of infinitesimal sides and applying the preceding solution to each of these sides making the momentum integral continuous at each vortex the problem is thereby reduced to the solution of a first order differential equation
CRAN	the effect of shallow water on wave resistance the effect of shallow water on wave resistance the general character of experimental results dealing with the effect of shallow water on ship resistance may be stated briefly as follows   at low velocities the resistance in shallow water is greater than in deep water the speed at which the excess is first appreciable varying with the type of vessel as the speed increases the excess resistance increases up to a maximum at a certain critical velocity and then diminishes with still further increase of speed the resistance in shallow water ultimately becomes and remains less than that in deep water at the same speed the maximum effect is the more pronounced the shallower the water for further details and references one may refer to standard treatises but one quotation may be made in regard to the critical velocity this maximum appears to be at about a speed such that a trochoidal wave travelling at this speed in water of the same depth is about times as long as the vessel it was at one time supposed that the speed for maximum increase in resistance was that of the wave of translation this however holds only for water whose depth is less than for greater depths the speed of the wave of translation rapidly becomes greater than the speed of maximum increase of resistance in a recent analysis of the data h m weitbrecht expresses a similar conclusion by stating that for each depth of water there is a critical velocity but that the critical velocity does not vary as the square root of the corresponding depth
CRAN	the hodographic transformation in transonic flow the hodographic transformation in transonic flow the author studies the problem of finding the shape of a symmetrical nozzle with the velocity along the axis x axis specified the velocity along each streamline is assumed to increase steadily the singularity at the sonic velocity and to the axis of the nozzle is first studied in the physical plane by using a power series in in the hodograph plane the two characteristics of the hodograph differential equation passing through the sonic point and are lines of branch points the region between these lines is a region of triple valuedness for the stream function outside this region is single valued there are also singularities at the sonic point and the point corresponding to the specified condition at the exit of the nozzle the author then proposes to construct in the hodograph plane by at the exit velocity and 3 a finite sum regular throughout sin where r is the square of the velocity and the are hypergeometric functions the as are fixed by the required approximation to the specified velocity distribution along the axis this solution is single valued convergent and represents except a region near the sonic point in the nozzle for this excluded region the author inverts the solution to obtain a power series in for 0 this is shown to be convergent for the region of interest the type of solution considered by the author gives a nozzle having an infinitely long supersonic part
CRAN	temperature charts for induction and constant temperature heating temperature charts for induction and constant temperature heating charts are presented for determining complete temperature historics in spheres cylinders and plates it is shown that for values of the dimensionless time ratio x greater than 0 2 the heating equations reduce to such a simple form that for each shape two charts which give temperatures at any position within the heated or cooled bodies can be plotted it is also shown that the usual simple heating and cooling charts can also be used for the determination of temperatures and heating times in bodies heated by a constant rate of heat generation at the surface induction heating finally a two dimensional chart is given for finding heating times in short cylinders thereby eliminating the trial and error solution that is necessary when heating times are found from the present one dimensional charts
CRAN	numerical methods for transient heat flow numerical methods for transient heat flow this paper deals with the application of numerical methods for the solution of heat conduction problems their generality being extended in the following ways may proceed most rapidly to a solution or may proceed more slowly and with greater precision b criteria are developed for the choice of modulus to insure convergence this is most important at a convective surface c a method is developed for handling k and c when these properties vary independently with temperature a comprehensive appendix gives the derivations and the use of equations and charts is demonstrated by typical examples
CRAN	approximate analytical solutions for hypersonic flow past slender power law bodies approximate analytical solutions for hypersonic flow past slender power law bodies approximate analytical solutions are presented for two dimensional and axisymmetric hypersonic flow over blunt nosed slender bodies whose shapes follow a power law variation in particular the body shape is given by where is the transverse body ordinate is the streamwise distance from the nose and m is a constant in the range both zero order solutions and first order small but nonvanishing values of solutions are presented where m is the free stream mach number and is a characteristic body or streamline slope the zero order shock shape is similar to the body shape for these flows the solutions are found within the framework of hypersonic slender body theory the limiting case m 1 corresponds to a wedge or cone flow the limiting case corresponds to a constant energy flow the latter cases are included so that the present study may be applied to all flows wherein the zero order shock shape is given by with m in the range flow fields associated with shock shapes having values of m outside this range are also discussed for all values of except m 1 certain portions of the flow field riolate the hypersonic slender body approximations while other portions are consistent with these approximations for m 1 all portions of the flow field are consistent with the approximations the approximate solutions are found as follows the asymptotic form of the flow in the vicinity of the body surface is used as a guide to write approximate expressions for the dependent variables these expressions exactly satisfy the continuity and energy equations and contain arbitrary constants which are evaluated so as to satisfy boundary conditions at the shock the approximate solutions do not satisfy the lateral momentum equation except at the shock and for the first order problem at the body surface the results of the approximate solutions are compared with numerical integrations of the equations of motion for various values of m and ratio of specific heats good agreement is noted particularly when m and are both near one the shock is relatively close to the body for the latter cases sufficient results are presented to evaluate the accuracy of the approximate method for various values of m and
CRAN	supersonic flow past a family of blunt symmetric bodies supersonic flow past a family of blunt symmetric bodies some 100 numerical computations have been carried out for unyawed bodies of revolution with detached bow waves the gas is assumed perfect with free stream mach numbers are taken as 1 2 1 5 2 3 4 6 10 and the results are summarized with emphasis on the sphere and paraboloid
CRAN	nearly circular transfer trajectories for descending satellites nearly circular transfer trajectories for descending satellites simplified expressions describing the transfer from a satellite orbit to the point of atmospheric entry are derived the expressions are limited to altitude changes that are small compared with the earths radius and velocity changes small compared with satellite velocity they are further restricted to motion about a spherical nonrotating earth the transfer orbit resulting from the application of thrust in any direction at any point in an elliptic orbit is considered expressions for the errors in distance miss distance and entry angle due to an initial misalinement and magnitude error of the deflecting thrust are presented the largest potential contributing factor towards a miss distance stems from the misalinement of the retrovelocity increment if this velocity increment is pointed in direct opposition to the flight path a 1 misalinement leads to a miss distance of 34 5 miles however it is shown that this error can be avoided by applying the velocity increment at an angle between 120 and 150 below the flight path direction the guidance and accuracy requirements to establish a circular orbit in addition to the corrections applied to transform elliptic orbits into circular ones are also discussed
CRAN	an analysis of the corridor and guidance requirements for supercircular entry planetary atmospheres an analysis of the corridor and guidance requirements for supercircular entry planetary atmospheres an analysis is presented of supercircular entry into a planets atmosphere giving particular attention to the corridor through which spacecraft must be guided in order to accomplish various maneuvers a dimensionless parameter based on conditions at the conic perigee altitude is introduced for characterizing supercircular entries and conveniently prescribing corridor widths associated with elliptic parabolic or hyperbolic approach trajectories the analysis applies to vehicles of arbitrary weight shape and size illustrative calculations are made for venus earth mars jupiter and titan for nonlifting vehicles having fixed aerodynamic coefficients curves are presented of dimensionless parameters from which can be calculated the maximum deceleration maximum rate of laminar convective heating and total laminar heat absorbed during single pass entry at velocities up to twice circular velocity for lifting vehicles curves are presented of the maximum deceleration and overshoot boundary of an entry corridor equations are presented for estimating laminar aerodynamic heating from the maximum deceleration it is shown that the corridor width is independent of vehicle weight dimensions and drag coefficient provided these are the same at the overshoot boundary as at undershoot the corridors of certain planets can be broadened markedly by the application of aerodynamic lift for example the 10 earth g corridor width for single pass nonlifting parabolic entry is increased from to 52 51 and 52 miles respectively by employing a lift drag ratio of 1 the use of aerodynamic lift does not increase appreciably the corridors of mars and titan all corridor widths decrease rapidly as the entry velocity is increased terminal guidance requirements on accuracy of velocity and flight path angle for successfully entering various corridors are compared with analogous requirements for putting a satellite into orbit for hitting the moon from the earth and for achieving icbm accuracy consideration is given to the terminal guidance problem involved in using a planets atmosphere  rather than rocket fuel  to effect orbital transfers from heliocentric to planeto centric motion thereby converting a hyperbolic approach trajectory to an elliptic orbit about the target planet this fuel saving maneuver appears technologically feasible for certain planetary voyages and implies the possibility of achieving a large reduction in required earth lift off weight of chemical propulsion systems
CRAN	an approximate analytical method for studying entry into planetary atmospheres an approximate analytical method for studying entry into planetary atmospheres the pair of motion equations for entry into a planetary atmosphere is reduced to a single ordinary nonlinear differential equation of second order by disregarding two relatively small terms and by introduring a certain mathematical transformation the reduced equation includes various terms certain of which represent the gravity force the centrifugal acceleration and the lift force if these particular terms are disregarded the differential equation is linear and yields precisely the solution of allen and eggers applicable to ballistic entry at relatively steep angles of descent if all the other terms in the basic equation are disregarded corresponding to negligible vertical acceleration and negligible vertical component of drag force the resulting truncated differential equation yields the solution of sanger for equilibrium flight of glide vehicles with relatively large lift drag ratios a number of solutions for lifting and nonlifting vehicles entering at various initial angles also have been obtained from the complete nonlinear equation these solutions are universal in the sense that a single solution determines the motion and heating of a vehicle of arbitrary weight dimensions and shape entering an arbitrary planetary atmosphere one solution is required for each lift drag ratio these solutions are used to study the deceleration heating rate and total heat absorbed for entry into venus earth mars and jupiter from the equations developed for heating rates and from available information on human tolerance limits to acceleration stress approximate conditions for minimizing the aerodynamic heating of a trimmed vehicle with constant lift drag ratio are established for several types of manned entry a brief study is included of the process of atmosphere braking for slowing a vehicle from near escape velocity to near satellite velocity
CRAN	skin friction measurements in incompressible flow skin friction measurements in incompressible flow experiments have been conducted to measure in incompressible flow the local surface shear stress and the average skin friction coefficient for a turbulent boundary layer on a smooth flat plate having zero pressure gradient the local surface shear stress was measured by a floating element skin friction balance and also by a calibrated total head tube located on the surface of the test wall the average skin friction coefficient was obtained from boundary layer velocity profiles the boundary layer profiles were also used to determine the location of the virtual origin of the turbulent boundary layer data were obtainec for a range of reynolds numbers from 1 million to about 45 million with an attendant change in mach number from 0 11 to 0 32 the measured local skin friction coefficients obtained with the floating element balance agree well with those of schultz grunow and kempf for reynolds numbers up to 45 million the measured average skin friction coefficients agree with those given by the schoenherr curve in the ranges of reynolds numbers from 1 to 3 million and 30 to 45 million in the range of reynolds numbers from 3 to 30 million the measured values are less than those predicted by the schoenherr curve the results show that the univeral skin friction constants proposed by coles appraoch asymptotically a constant value at reynolds numbers exceeding mentioned constants and the limited reynolds number range of the present investigation there is some doubt as to the validity of any turbulent skin friction law written on the basis of the present results hence no new friction law is proposed the frictional resistance of a flat plate was calculated by means of the momentum method and also the integrated measured local surface shear for reynolds numbers from 14 million to 45 million both methods give about the same result whereas at lower values of reynolds number the momentum method based on velocity profiles uncorrected for the effects of turbulence results in a frictional resistance as much as 4 percent higher than that of the integrated shear the measurement of local surface shear by a calibrated preston tube appears to be accurate and inexpensive the calibration as given by preston must be modified slighlty however to yield the results obtained from the floating element skin friction balance
CRAN	flow of chemically reacting gas mixtures flow of chemically reacting gas mixtures suitable forms of the equations for the flow of an inviscid non heat conducting gas in which chemical reactions are occurring are derived the effects of mass diffusion and non equilibrium amongst the internal modes of the molecules are neglected special attention is given to the speeds of sound in such a gas mixture and a general expression for the ratio of frozen to equilibrium sound speeds is deduced an example is given for the ideal dissociating gas the significance of the velocity defined by the ratio of the convective derivatives of pressure and density is explained it is the velocity which exists at the throat of a convergent divergent duct under maximum mass flow conditions and it is shown that this velocity depends on the nozzle geometry as well as on the reservoir conditions as an illustration the phenomena of sound absorption and dispersion are discussed for the ideal dissociating gas the results can be concisely expressed in terms of the frozen and equilibrium sound speeds the frequency of the harmonic sound vibration and a characteristic time for the rate of progress of the reaction
CRAN	linearized flow of a dissociating gas linearized flow of a dissociating gas the equations for planar two dimensional steady flow of an ideal dissociating gas are linearized assuming small disturbances to a free stream in chemical equilibrium as an example of their solution the flow past a sharp corner in a supersonic stream is evaluated and the variations of flow properties in the relaxation zone are found numerical illustrations are provided using an oxygen like ideal gas and comparisons made with a characteristics solution the flow past a sharp corner can be studied in a conventional shock tube and it may be possible to verify the present theory experimentally in particular it may prove feasible to use the results to obtain a measure of the reaction rates in the gas mixture
CRAN	heat conduction through a gas with one inert internal model heat conduction through a gas with one inert internal model the rate of energy transfer between parallel flat plates is evaluated when the stagnant gas between them is polyatomic with one inert internal mode deviations of the thermal conductivity from the complete equilibrium of the inert mode relaxation time and the effectiveness of the walls in exciting or de exciting this mode the results are obtained via a linear theory consistent with small temperature differences between the plates it is found that the eucken value of conductivity could be exceeded if the relaxation times are non zero and the plates very effective in exciting the inert mode when relaxation times are very short the effect of the walls on the energy transfer rate is small but the walls make their presence felt by distorting the temperature profiles in boundary layers adjacent to the walls which are of order in thickness time this result is analogous to hirschfelders 1956 for the case of chemical reactions for experimental measurement of conductivity in a hot wire cell type of apparatus it is shown that extrapolation of measured reciprocal conductivities to zero reciprocal pressure should load to the full eucken value it is also shown that the slope of reciprocal apparent measured conductivity versus reciprocal pressure curves is a function of relaxation time as well as of the accommodation coefficients it is quite possible that the relaxation effect here is comparable with the temperature jump effects even for rotation in diatomic molecules
CRAN	on the sudden contact between a hot gas and a cold solid on the sudden contact between a hot gas and a cold solid the flow induced by the sudden contact between a semi infinite expanse of gas and a solid initially at different temperatures is examined on the basis of a linear continuum theory for times large compared with the mean time between molecular collisions in the gas the velocity and pressure disturbances are found to be concentrated around a wave front propagating out from the interface at the ambient isentropic sound speed whilst near to the interface these disturbances are small and the gas temperatures are nearly equal to those predicted by the classical constant pressure heat conduction theory the possible significance of these results in connection with reflected shock wave techniques to measure high temperature gas properties is commented upon
CRAN	the interaction of a reflected shock wave with the boundary layer in a shock tube the interaction of a reflected shock wave with the boundary layer in a shock tube ideally the reflection of a shock from the closed end of a shock tube provides for laboratory study a quantity of stationary gas at extremely high temperature because of the action of viscosity however the flow in the real case is not one dimensional and a boundary layer grows in the fluid following the initial shock wave in this paper simplifying assumptions are made to allow an analysis of the interaction of the shock reflected from the closed end with the boundary layer of the initial shock afterflow the analysis predicts that interactions of several different types will exist in different ranges of initial shock mach number it is shown that the cooling effect of the wall on the afterflow boundary layer accounts for the change in interaction type an experiment is carried out which verifies the existence of the several interaction regions and shows that they are satisfactorily predicted by the theory along with these results sufficient information is obtained from the experiments to make possible a model for the interaction in the most complicated case this model is further verified by measurements made during the experiment the case of interaction with a turbulent boundary layer is also considered identifying the type of interaction with the state of turbulence of the interacting boundary layer allows for an estimate of the state of turbulence of the boundary layer based on an experimental investigation of the type of interaction
CRAN	a low density wind tunnel study of shock wave structure and relaxation phenomena in gases a low density wind tunnel study of shock wave structure and relaxation phenomena in gases the profiles and thicknesses of normal shock waves of moderate strength have been determined experimentally in terms of the variation of the equilibrium temperature of an insulated transverse cylinder in free molecule flow the shock waves were produced in a steady state in the jet of a low density wind tunnel at initial mach numbers of 1 72 and 1 82 in helium and 1 78 the shock thickness determined from the maximum slope of the cylinder temperature profile varied from mean free path in the supersonic stream a comparison between the experimental shock profiles and various theoretical predictions leads to the tentative conclusions that 1 the navier stokes equations are adequate for the description of the shock transition for initial mach numbers up to 2 and 2 the effects of rotational relaxation times in air can be accounted for by the introduction of a second or bulk viscosity coefficient equal to about two thirds of the ordinary shear viscosity
CRAN	some aerodynamic considerations of nozzle afterbody combination some aerodynamic considerations of nozzle afterbody combination the aerodynamic problems associated with propulsion system installations have assumed a role of vital importance in the development of supersonic aircraft although air induction systems have received moderate attention in the literature considerably less information can be found on the design and installation of turbojet exit nozzles this condition should not be interpreted to indicate a lack of problems in jet exit design as flight speeds reach supersonic levels it becomes increasingly difficult to achieve nozzle installations which are efficient over the entire speed range the difficulties largely stem from the fact that the goals of high jet thrust and low afterbody drag are not always compatible in many of the compromise solutions it is generally unsatisfactory to examine isolated nozzle and afterbody performance rather they must be treated as a unit and the complex effects of jet interaction with the external stream must be taken into account to accomplish this the nozzle and air frame designers must closely coordinate their efforts some of the aerodynamic problems of nozzle afterbody combinations are outlined in this report particular attention is devoted to the influence of the jet stream interaction on both nozzle thrust and after body drag for this purpose use is made of shock  boundary layer interaction concepts this approach although not precise correctly predicts many trends and is generally enlightening
CRAN	the effect of a central jet on the base pressure of a cylindrical afterbody in a supersonic stream the effect of a central jet on the base pressure of a cylindrical afterbody in a supersonic stream this report describes an experimental investigation of the factors affecting the base flow and jet structure behind a cylindrical after body with a central nozzle seven interchangeable nozzles were tested six of these were convergent divergent with a design mach number of 2 0 jet base diameter ratios ranging from 0 2 to 0 8 and nozzle divergence angles ranging from convergent with a jet base diameter ratio of 0 6 in the main experimental programme the free stream mach number was 2 0 and the boundary layer was turbulent both on the after body and in the nozzle measurements were made of the base pressure the surface pressure distribution inside the nozzle the overall thrust and the nozzle mass flow over a range of jet pressures this programme was supplemented by comparative tests with the jet exhausting into still air static tests readings were taken of the internal nozzle pressures and the jet thrust at different jet pressures schlieren photography was used extensively throughout the results of the tests with external flow are presented in the form of curves showing the separate effects of jet pressure ratio jet base diameter ratio nozzle design mach number and nozzle divergence angle on the base pressure and overall thrust the special case of base bleed is discussed separately similar curves are included for the static tests these show the effect of jet pressure ratio and nozzle geometry on the jet thrust a general method of correlating data on annular base pressures is proposed and discussed essentially this method compares the pressure on an annular base with the calculated pressure on the corresponding two dimensional base it correlates the present results reasonably well but is less successful when applied to more extensive data
CRAN	investigation at supersonic speeds of the effects of jet mach number and divergence angle of the nozzle upon the pressure of the base annulus of a body of revolution investigation at supersonic speeds of the effects of jet mach number and divergence angle of the nozzle upon the pressure of the base annulus of a body of revolution an investigation has been conducted in the langley 9 inch supersonic tunnel to determine the jet effects for varying jet mach number and nozzle divergence angle upon the pressure on the base annulus of a model with a cylindrical afterbody the tests were conducted over a wide range of jet static pressure ratios and at a reynolds number of approximately free stream mach numbers of 1 62 1 94 and 2 41 all testing was conducted with an artificially induced turbulent boundary layer along the model in the lower range of jet static pressure ratios jet flow from a sonic or supersonic nozzle affected the pressure acting on the base annulus in essentially the same manner as shown in naca rm e53h25 which covers jet static pressure ratios up to about present results showed that the base pressure tends to level off with increasing jet static pressure ratio and at the extreme static pressure ratios reached in tests with sonic nozzles the base pressure began to decrease except in the lower range of jet static pressure ratios nozzle divergence angle generally had a larger effect on the base pressures than nozzle mach number the increase in base pressure for a change in divergence angle from 0 to 10 was small compared to the increase when the divergence angle was changed from and other data indicates that the effects of divergence angle were reduced when the ratio of jet exit diameter to base diameter was decreased jet mach number effects increased with increase in stream mach number
CRAN	experiments with static tubes in a supersonic airstream experiments with static tubes in a supersonic airstream systematic tests have been made at a mach number of 1 6 on a family of static tubes the variables which have been investigated are the shape of the nose the distance of the holes downstream and the inclination of the tube to the flow pressure measurements have also been made in the vicinity of a shock wave and close to a wall
CRAN	base pressure at subsonic speeds in the presence of a supersonic jet base pressure at subsonic speeds in the presence of a supersonic jet this paper presents the results of an experimental investigation into the effect of supersonic jets upon the base pressure of a bluff cylinder in a uniform subsonic flow the ratio of jet diameter to base diameter was 0 1875 jet stagnation pressures giving slight under expansion of the jet cause an increase in the base pressure but for larger jet stagnation pressures the base pressure is again reduced a simple theory based on a momentum integral shows the dependence of the base drag upon the jet and free stream speeds and upon the dimensions of the jet and the base
CRAN	the mixing of free axially symmetrical jets of mach number 1 40 the mixing of free axially symmetrical jets of mach number 1 40 axially symmetrical supersonic fully expanded jets of diameter about 0 75 in and of mach number 1 40 issuing into an atmosphere at rest were investigated by schlieren and shadow photography and by pressure traversing the development of the jets was found to depend critically on the strength of the shock waves in the core of the jet at the nozzle exit with strong shock waves present the jet spread very rapidly and was very unsteady the jet did in some cases break up into large eddies of the same size as the diameter of the jet when no disturbances were present in the core of the jet the spreading was far more gradual and the jet showed only slight unsteadiness the turbulent mixing region of the first part of the jet with strong shock waves was investigated in detail by pitot tubes the first inch was found to correspond to a two dimensional half jet the velocity profiles were similar and well represented by the error integral the rate of spreading was only half the value for low speed flow by integrations across the mixing region the entrainment and the loss of kinetic energy were determined these quantities were found to agree well with the values estimated by assuming an error integral velocity profile
CRAN	on full dispersed shock waves in carbon dioxide on full dispersed shock waves in carbon dioxide it is pointed out that for shock mach numbers between 1 and that the adjustments in the energy in all the degrees of freedom proceed slowly and in parallel and occur over a distance large compared with the mean free path theoretical velocity profiles for such shock waves are given and found to be in excellent agreement with interferometric shock tube observations
CRAN	an analysis of base pressure at supersonic speeds and comparison with experiment an analysis of base pressure at supersonic speeds and comparison with experiment in the first part of the investigation an analysis is made of base pressure in an inviscid fluid both for two dimensional and axially symmetric flow it is shown that for two dimensional flow and also for the flow over a body of revolution with a cylindrical sting attached to the base there are an infinite number of possible solutions satisfying all necessary boundary conditions at any given free stream mach number for the particular case of a body having no sting attached only one solution is possible in an inviscid flow but it corresponds to zero base drag accordingly it is concluded that a strictly inviscid fluid theory cannot be satisfactory for practical applications since the exact inviscid fluid theory does not adequately describe the conditions of a real fluid flow an approximate semi empirical theory for base pressure in a viscous fluid is developed in a second part of the investigation the semi empirical theory is based partly on inviscid flow calculations and is restricted to airfoils and bodies without boat tailing in this theory an attempt is made to allow for the effects of mach number reynolds number profile shape and type of boundary layer flow the results of some recent experimental measurements of base pressure in two dimensional and axially symmetric flow are presented for purposes of comparison some experimental results also are presented concerning the support interference effect of a cylindrical sting and the interference effect of a reflected bow wave on measurements of base pressure in a supersonic wind tunnel
CRAN	boundary layer over a flat plate in presence of shear flow boundary layer over a flat plate in presence of shear flow the governing equations of an incompressible boundary layer over a flat plate in the presence of a shear flow with finite vorticity are derived for large vorticity a similarity solution is obtained for moderate vorticity one of the governing equations is replaced by an approximate one for which similarity solutions exist
CRAN	some problems on heat conduction in stratiform bodies some problems on heat conduction in stratiform bodies problems on heat conduction in multilayer bodies lead usually to complicated calculations the present paper gives an idea of specific difficulties arising in the case of infinite composite solides general deductions are applied to a special class of questions
CRAN	effect of roughness on transition in supersonic flow effect of roughness on transition in supersonic flow further experiments carried out in the 12 inch supersonic wind tunnel of the jet propulsion laboratory of the california institute of technology to investigate the effect of three dimensional roughness elements spheres on boundary layer transition on a 10 transfer are reported herein the local mach number for these tests was minimum effective size of trip required to bring transition to its lowest reynolds number varies as the one fourth power of the distance from the apex of the cone to the trip use of available data at other mach numbers indicates that the mach number influence for effective tripping is taken into account by the simple expression
CRAN	properties of impact pressure probes in free molecule flow properties of impact pressure probes in free molecule flow an expression has been derived for the mass flow through a circular tube in free molecule flow when the tube and gas are in relative motion the gas entering the tube is assumed to have a maxwellian distribution function and the molecular reflection process at the wall is assumed to be diffuse the theory has been used to determine the pressure read by an impact probe in free molecule flow although the general expressions derived apply to any value of gas velocity and tube size the detailed calculations for the pressure probe are difficult except for the case of low speeds and long tubes an experimental check of the theory has been carried out using impact probes in a whirling arm apparatus and in the utia low density wind tunnel agreement between theory and experiment is quite satisfactory
CRAN	scale models for thermo aeroelastic research scale models for thermo aeroelastic research an investigation is made of the parameters to be satisfied for thermo aeroelastic similarity it is concluded that complete similarity obtains only when aircraft and model are identical in all respects including size by limiting consideration to conduction effects by assuming the major load carrying parts of the structure are in regions where the flow is either entirely laminar or entirely turbulent and by assuming a specific relationship between reynolds number and nusselt number an approach to similarity can be achieved for small scale models experimental and analytical work is required to check on the validity of these assumptions it appears that existing hot wind tunnels will not be completely adequate for thermo aeroelastic work and accordingly a possible layout for the type of tunnel required is described automatic programmed control of the tunnel would appear to be necessary
CRAN	some possibilities of using gas mixtures other than in aerodynamic research some possibilities of using gas mixtures other than in aerodynamic research a study is made of the advantages that can be realized in compressible flow research by employing a substitute heavy gas in place of air most heavy gases considered in previous investigations are either toxic chemically active or as in the case of the freons have a ratio of specific heats greatly different from air the present report is based on the idea that by properly mixing a heavy monatomic gas with a suitable heavy polyatomic gas it is possible to obtain a heavy gas mixture which has the correct ratio of specific heats and which is nontoxic nonflammable thermally stable chemically inert and comprised of commercially available components calculations were made of wind tunnel characteristics for 63 gas pairs comprising 21 different polyatomic gases properly mixed with each of three monatomic gases argon krypton and xenon for a given mach number reynolds number and tunnel pressure a gas mixture wind tunnel having the same specific heat ratio as air would be appreciably smaller and would require much less power than a corresponding air wind tunnel analogous though different advantages can be realized in compressor research and in firing range research the most significant applications perhaps arise through selecting and proportioning a gas mixture so as to have at ordinary wind tunnel temperatures certain dimensionless characteristics which air at flight temperatures possesses but which air at ordinary wind tunnel temperatures does not possess characteristics which involve the relaxation time or bulk viscosity the variation of viscosity with temperature and the variation of specific heat with temperature fall within this category other applications arise in heat transfer research since certain gas mixtures can be concocted to have any prandtl number in the range at least between 0 2 and 0 8
CRAN	base pressure in supersonic flow base pressure in supersonic flow the problem of accurately predicting the pressure and wake configuration at the base of bodies in supersonic flow is an extremely important one inasmuch as a sizeable portion of the total drag of a given body may be attributable to the low pressure in this region although a great deal of theoretical and experimental work has been done in this field there does not yet exist a satisfactory method for accurate predictions this paper represents an excellent effort to experimentally confirm analytically deduced concepts a large amount of experimental data on body shapes such as wedges cones and cone cylinders has been obtained over a range of mach numbers up to 4 the data are thoroughly discussed with respect to analytical deductions on the basis of the evidence accumulated it is concluded that the boundary layer thickness has only a small effect on the base pressure for axisymmetric bodies and for two dimensional bodies when the base height to chord ratios are of the order reviewer believes this report is a significant contribution in the field of base pressure and wake flow phenomena
CRAN	investigation of separated flows in supersonic and subsonic streams with emphasis on the effect of transition investigation of separated flows in supersonic and subsonic streams with emphasis on the effect of transition experimental and theoretical research has been conducted on flow separation associated with steps bases compression corners curved surfaces shock wave boundary layer reflections and configurations producing leading edge separation results were obtained from pressure distribution measurements shadow graph observations high speed motion pictures and oil film optics the maximum scope of measurement encompassed mach numbers between 0 4 and 3 6 and length reynolds numbers between 4000 and 5000000 the principal variable controlling pressure distribution in the separated flows was found to be the location of transition relative to the reattachment and separation positions classification is made of each separated flow into one of three regimes and turbulent with transition upstream of separation by this means of classificaiton it is possible to state rather literal results regarding the steadiness of flow and the influence of reynolds number within each regime for certain pure laminar separations a theory for calculating dead air pressure is advanced which agrees well with subsonic and supersonic experiments this theory involves no empirical information and provides an explanation of why transition location relative to reattachment is important a simple analysis of the equations for interaction of boundary layer and external flow near either laminar or turbulent separation indicates the pressure rise to vary as the square root of the wall shear stress at the beginning of interaction various experiments substantiate tnis variation for most test conditions an incidental observation is that the stability of a separated laminar mixing layer increases markedly with an increase in mach number the possible significance of this observation is discussed
CRAN	an analysis of base pressure at supersonic velocities and comparison with experiment an analysis of base pressure at supersonic velocities and comparison with experiment in the first part of the investigation an analysis is made of base pressure in an inviscid fluid both for two dimensional and axially symmetric flow it is shown that for two dimensional flow and also for the flow over a body of revolution with a cylindrical sting attached to the base there are an infinite number of possible solutions satisfying all necessary boundary conditions at anh given free stream mach numger for the particular case of a body having no sting attached only one solution is possible in an inviscid flow but it corresponds to zero base drag accordingly it is concluded that a strictly inviscid flow theory cannot be satisfactory for practical applications an approximate semi empirical analysis for base pressure in a viscous fluid is developed in a second part of the investigation the semi empirical analysis is based partly on inviscid flow calculations in this theory an attempt is made to allow for the effects of mach number reynolds number profile shape and type of boundary layer flow some measurements of base pressure in two dimensional and axially symmetric flow are presented for purposes of comparison experimental results then are presented concerning the support interference effect of a cylindrical sting and the interference effect of a reflected air wave on measurements of base pressure in a supersonic wind tunnel
CRAN	experimental investigation of base pressure on blunt trailing edge wings of supersonic velocities experimental investigation of base pressure on blunt trailing edge wings of supersonic velocities measurements of base pressure are presented for 29 blunt trailing edge wings having an aspect ratio of 3 0 and various airfoil profiles the different profiles comprised thickness ratios between 0 05 and 0 10 boattail angles between   2 9 and 20 and ratios of trailing edge thickness to airfoil thickness between 0 2 and 1 0 the tests were conducted at mach numbers of 1 25 1 5 2 0 and 3 1 for each mach number the reynolds number and angle of attack were varied the lowest reynolds number investigated was 0 2 x 10 and the highest was 3 5 x 10 measurements on each wing were obtained separately with turbulent flow and laminar flow in the boundary layer span wise surveys of the base pressure were conducted on several wings the results with turbulent boundary layer flow showed only small effects on base pressure of variations in reynolds number airfoil profile shape boattail angle and angle of attack the principal variable affecting the base pressure for turbulent flow was the mach number at the highest mach number investigated 3 1 the ratio of boundary layer thickness to trailing edge thickness also affected the base pressure significantly the results obtained with laminar boundary layer flow to the trailing edge showed that the effect of reynolds number on base pressure was large in all but a few exceptional cases the effects on base pressure of variations in angle of attack and in profile shape upstream of the base were appreciable though not large the principal variable affecting the base pressure for laminar flow was the ratio of boundary layer thickness to trailing edge thickness for a few exceptional cases involving laminar flow to the trailing edge the effects on base pressure of variations in profile shape boattail angle and angle of attack were found to be unusually large in such cases the variation of base pressure with angle of attack was discontinuous and exhibited a hysteresis stroboscopic schlieren observations at a mach number of 1 5 indicated that these apparently special phenomena were associated with a vortex trail of relatively high frequency
CRAN	on magnetohydrodynamic shock waves on magnetohydrodynamic shock waves in the earlier attempts at finding the jump conditions across a hydromagnetic shock wave 1 2 3 various simplifying assumptions regarding the shape of the shock and the dimensions and the character of the motion are made from that analysis it is possible to write down the jump conditions in a higher degree of generality 4 the shock conditions for magnetohydrodynamic flows can however be derived in their full generality with the help of the transport equation as used by thomas 5 in the derivation of shock conditions in conventional gas dynamics the purposes of this paper are cover the present more general case that every flow and field quantity downstream from the shock wave is expressible separately in terms of the known values of these quantities upstream from the shock wave in this rearranged form of the equations various effects of the shock wave can be easily read off the shock conditions along the same lines as in conventional gas dynamics
CRAN	a theory for the core of a leading edge vortex a theory for the core of a leading edge vortex in the flow past a slender delta wing at incidence can be observed a roughly axially symmetric core of spiralling fluid formed by the rolling up of the shear layer that separates from a leading edge the aim in this report is to predict the flow field within this vortex core given appropriate conditions at its outside edge the basic assumptions are core in addition it is assumed that the flow is axially symmetric and incompressible together these admit outer and inner solutions for the core from the equations of motion for the outer solution the sub core is ignored and the flow is taken to be inviscid but rotational and conical the resulting solution consists of simple expressions for the velocity components and pressure for the inner solution which applies to the diffusive sub core the flow is taken to be laminar and approximations some based on the boundary conditions and some analogous to those of boundary layer theory are made the solution obtained in this case is a first approximation and is presented in tabular form a sample calculation yields results which are in good qualitative and fair quantitative agreement with experimental measurements
CRAN	on the hypersonic viscous flow past slender bodies of revolution on the hypersonic viscous flow past slender bodies of revolution a similar solution of the hypersonic viscous flow past slender bodies of revolution is deduced for a special case when the radial coordinate of the body surface at section x is proportional to x where the radial coordinate have the comparable order value with the thickness of the boundary layer here similar is used in the direct meaning that distributions in the boundary layer keep the similar form lengthwise calculations are accomplished for the region of strong interaction between the boundary layer and the shock wave from several calculations it may be expected that if the thickness of the body becomes small the thickness of the layer in which the longitudinal velocity component u is rapidly decreased also becomes small and in the major part of the boundary layer only the normal component v is increased further if the thickness of the body is increased then the height of the shock wave the pressure on the wall and the shear stress at the wall are also increased while the boundary layer thickness is decreased the nose region is excluded by the reason that the ordinary boundary layer theory will be invalid there
CRAN	a study of inviscid flow about air foils at high supersonic speeds a study of inviscid flow about air foils at high supersonic speeds steady flow about curved airfoils at high supersonic speeds is investigated analyticially with the assumption that air behaves as a diatomic gas it is found the the shock expansion method may be used to predict the flow about curved airfoils up to extremely high mach numbers provided the flow deflection angles are not too close to those corresponding to shock detachment this result applies not only to the determination of the surface pressure distribution but also to the determination of the whole flow field about an airfoil verification of this observation is obtained with the aid of the method of characteristics by extensive calculations of the pressure gradient and shock wave curvature at the leading edge and by calculations of the pressure distribution on a 10 percent thick biconvex airfoil at 0 angle of attack an approximation to the shock expansion method for thin airfoils at high mach numbers is also investigated and is found to yield pressures in error by less than 10 percent at mach numbers above three and flow deflection angles up to 25 this slender airfoil method is relatively simple in form and thus may prove useful for some engineering purposes effects of caloric imperfections of air manifest in disturbed flow fields at high mach numbers are investigated particular attention being given to the reduction of the ratio of specific heats so long as this ratio does not decrease appreciably below to include the effects of these imperfections should be substantially as accurate as for ideal gas flows this observation is verfied with the aid of a generalized shock expansion method and a generalized method of characteristics employed in forms applicable for local air temperatures up to about 5000 rankine the slender airfoil method is modified to employ an average value of the ratio of specific heats for a particular flow field this simplified method has essentially the same accuracy for imperfect gas flows as its counterpart has for ideal gas flows an approximate flow analysis is made at extremely high mach numbers where it is indicated that the ratio of specific heats may approach close to 1 in this case it is found that the shock expansion method may be in considerable error however the busemann method for the limit of infinite free stream mach number and specific heat ratio of 1 appears to apply with reasonable accuracy
CRAN	general theory of airfoil sections having arbitrary shape or pressure distribution general theory of airfoil sections having arbitrary shape or pressure distribution in this report a theory of thin airfoils of small camber is developed which permits either the velocity distribution corresponding to a given airfoil shape or the airfoil shape corresponding to a given velocity distribution to be calculated the procedures to be employed in these calculations are outlined and illustrated with suitable examples
CRAN	correlation of theoretical and photo thermoelastic results on thermal stresses in idealized wing structure correlation of theoretical and photo thermoelastic results on thermal stresses in idealized wing structure after a rather complete exploratory program described in previous papers the photo thermoelastic method was applied to the experimental evaluation of the thermal stress theories the new technique was correlated with several theories which analyzed the transient thermal stresses in idealized wing structures of high speed aircraft various theories were investigated which represented the same idealized wing models and differed from each other only in the simplifying assumptions regarding the temperature distributions in skin and webs the theories were evaluated by duplicating the boundary and initial conditions on plastic models and then by correlating the theories with the observed fringe orders in nondimensional form a significant general conclusion was reached after correlating the available theories and experimental results owing to simplifying assumptions concerning the thermal behavior in the flanges thermal stresses predicted by the available theories are all higher than the experimental observation in some cases the discrepancy is as great as 30 per cent
CRAN	pressure distributions axially symmetric bodies in oblique flow pressure distributions axially symmetric bodies in oblique flow a simple picture known from the work of i lotz of the flow over the forward part of a body of revolution in oblique flow is derived here from entirely elementary considerations the pressure at any point of the forward part of the body at any angle of incidence depends on three parameters whose values vary along the body the variation of these parameters along the body can be determined from a relatively small number of wind tunnel or water tunnel measurements the necessary water tunnel measurements have been made for four axially symmetric head shapes additional measurements have been made to illustrate the theoretical conclusions the data for each head shape are adequate for a determination of the pressure coefficient at any point on the head shapes at any angle of incidence up to 6 say in particular they can be used to determine the peak suction at any angle of incidence and so the conditions for the onset of cavitation on the head
CRAN	pressure distributions on three bodies of revolution to determine the effect of reynolds number up to and including the transonic speed range pressure distributions on three bodies of revolution to determine the effect of reynolds number up to and including the transonic speed range this paper presents the results of an investigation conducted in the langley 16 foot transonic tunnel to determine the effects of varying reynolds number on the pressure distribution on a transonic body of revolution at angles of attack through the transonic speed range the effect of a change in sting cone angle on the pressure distributions and a comparison of experimental incremental pressures with theory is also included the models were tested through a mach number range from 0 60 to 1 09 the reynolds number range based on body length was from 9 x 10 to 39 x diameter was 1 3 x 10 to 4 53 x 10 for the model at 8 angle of attack an increase in reynolds number from 9 x 10 to 39 x 10 affected the longitudinal pressure distributions very slightly these effects were of such a nature as to cause an increase of 0 05 in the normal force coefficient of the body when tested in the subcritical cross flow reynolds number range this increase is in agreement with theoretical approximations a comparison between experimental and theoretical values of the incremental pressure coefficient due to angle of attack indicated good agreement except at angles where separated flow areas existed over the body the effect of a change in sting cone angle from 5 to 9 on the pressure distribution of the 120 inch model was negligible up to a mach number of 1 05 at this mach number the effect was to cause a small increase in the velocity over the rear of the body
CRAN	investigation of a systematic group of naca 1   series cowlings with and without spinners investigation of a systematic group of naca 1   series cowlings with and without spinners an investigation has been conducted in the langley propeller research tunnel to study cowling spinner combinations based on the naca 1 series nose inlets and to obtain systematic design data for one family of approximately ellipsoidal spinners in the main part of the investigation 11 of the related spinners were tested in various combinations with 9 naca open nose cowlings which were also tested without spinners the effects of location and shape of the spinner shape of the inner surface of the cowling lip and operation of a propeller having approximately oval shanks were investigated briefly in addition a study was conducted to determine the correct procedure for extrapolating design conditions determined from the low speed test data to the design conditions at the actual flight mach number the design conditions for the naca 1 series cowlings and cowling spinner combinations are presented in the form of charts from which for wide ranges of spinner proportions and rates of internal flow cowlings with near maximum pressure recovery can be selected for critical mach numbers ranging from spinners and the effects of the spinners and the propeller on the cowling design conditions are presented separately to provide initial quantitative data for use in a general design procedure through which naca 1 series cowlings can be selected for use with spinners of other shapes by use of this general design procedure correlation curves established from the test data and derived compressible flow equations relating the inlet velocity ratio to the surface pressures on the cowling and spinner naca 1 series cowlings and cowling spinner combinations can be designed for critical mach numbers as high as 0 90
CRAN	measurement of two dimensional derivatives on a wing aileron tab system measurement of two dimensional derivatives on a wing aileron tab system measurements have been made of the direct two dimensional damping and stiffness derivatives for a in incompressible flow corrections arising from the apparatus are discussed and reference is made to an attempt to measure the direct tab derivatives the effects are shown of frequency parameter amplitude of oscillation reynolds number aileron angle and position of transition on the wing variation with frequency parameter is substantially the same as for vortex sheet theory and variation of amplitude produces little change in both derivatives at the lowest reynolds number there is little change in both derivatives with variation of aileron angle for the condition of natural transition but at higher reynolds numbers the stiffness derivatives increase at a forward movement of transition reduces the stiffness derivatives at the smaller aileron angles but at at the lowest reynolds number an increase results similar trends are observed for the damping derivatives above comparison with vortex sheet theory shows that the measured values of the stiffness and damping derivatives are approximately 0 6 of the theoretical values measurements have been made of the direct tab derivatives and cross aileron tab derivatives for a per cent aileron and 4 per cent approx tab in addition some measurements of the direct aileron derivatives have been made for comparison with earlier results together with a number of static derivatives for the wing and controls the influence is shown of frequency parameter reynolds number position of transition mean tab angle and sealing of the control hinge gaps some tests have been made with the ailcron set at minus 8 deg and the tab at plus 12 deg for which condition the hinge moment on the aileron was zero reasonable agreement with the values given by the equivalent profile theory is shown for both direct damping derivatives and for the direct tab stiffness derivative the direct aileron stiffness derivative shows some departure from the theoretical value when at and the natural transition comparison with the values given by flat plate theory gives the following approximate factors where suffix denotes the theoretical values
CRAN	calculation of derivatives for a cropped delta wing with subsonic leading edges oscillating in a supersonic airstream calculation of derivatives for a cropped delta wing with subsonic leading edges oscillating in a supersonic airstream the lift pitching moment and full span constant chord control hinge moment are derived for a cropped delta wing describing harmonic plunging and pitching oscillations of small amplitude and low frequency parameter in a supersonic air stream it is assumed that a the wing has subsonic leading edges b the wing is sufficiently thin and the mach number sufficiently supersonic to permit the use of linearised theory expressions for the various derivative coefficients are obtained for a particular delta wing of aspect ratio 1 8 and taper ratio these are avaluated and tabulated for mach numbers 1 1 1 15 1 2 1 3 1 4 1 5 1 6 and 1 944
CRAN	supersonic flow past oscillating airfoils including nonlinear thickness effects supersonic flow past oscillating airfoils including nonlinear thickness effects a solution to second order in thickness is derived for harmonically oscillating two dimensional airfoils in supersonic flow for slow oscillations of an arbitrary profile the result is found as a series including the third power of frequency for arbitrary frequencies the method of solution for any specific profile is indicated and the explicit solution derived for a single wedge nonlinear thickness effects are found generally to reduce the torsional damping and so to enlarge the range of mach numbers within which torsional instability is possible this destabilizing effect varies only slightly with frequency in the range involved in dynamic stability analysis but may reverse to a stabilizing effect at high flutter frequencies comparison with a previous solution exact in thickness suggests that nonlinear effects of higher than second order are practically negligible the analysis utilizes a smoothing technique that replaces the actural problem by one involving no kinked streamlines this stratagem eliminates all consideration of shock waves from the analysis yet yields the correct solution for problems that actually contain shock waves
CRAN	aircraft flutter aircraft flutter the term flutter is used here to denote maintained or violent oscillations of a structure due to aerodynamic forces acting in conjunction with both elastic and inertial forces attention is restricted to this particular branch of the more general field of aeroelasticity which embraces buffeting divergence and reversal of control as well as flutter airscrew flutter is not specifically considered the monograph is divided into three main parts each of which has been made self contained for the convenience of readers in the first part general methods for the investigation of aircraft flutter by theoretical analysis and by experiments on flutter models are set out and discussed a detailed account of the aerodynamic theory of wings in non uniform motion is not included since this has already been provided elsewhere but methods for the evaluation of the aerodynamic forces required in a theoretical flutter analysis are logically developed and a bibliography of researches on the aerodynamic theory is given in the appendix investigations on specific types of aircraft flutter  namely wing flutter control surface flutter and tab flutter  are discussed in part these various types of flutter are considered but the practical details of flutter prevention devices are omitted finally in part 3 methods for the experimental determination of airloads on oscillating aerofoil systems are described and available airload measurements are analysed and compared with theoretical results an attempt has been made to refer in the text to all relevant british work reported by the early part of 1947 foreign work has been mentioned in parts 1 and 2 only where necessary for the sake of completeness but in part 3 and the appendix all relevant foreign references known to the author have been included matrix notation has been used for the theoretical treatment in part 1 but otherwise its use has been avoided
CRAN	calculated velocity distributions and force derivatives for a series of high speed aerofoils calculated velocity distributions and force derivatives for a series of high speed aerofoils the polygon method of woods is used to calculate the velocity distribution over a number of two dimensional aerofoils at low incidence subcritical flows only being considered lift slopes and aerodynamic centres at zero lift are also calculated some comparisons with experimental results are made and these show good agreement at zero incidence
CRAN	a study of the application of airfoil section data to the estimation of the high subsonic speed characteristics of swept wings a study of the application of airfoil section data to the estimation of the high subsonic speed characteristics of swept wings estimates of the variation with mach number of the aerodynamic characteristics of swept wings are made on the basis of airfoil section data combined with span loading theory the analysis deals with examinations of some 26 wings and wing body combinations ranging in sweep angle from 30 to 60 and for mach numbers between 0 6 and 1 0 results of the study indicate that the two dimensional section data afford good qualitative information for such high speed aerodynamic characteristics as the variation with mach number of drag zero lift pitching moment coefficient and lift coefficient for flow separation quantitative estimates of the force and moment divergence mach numbers could not be made with any degree of certainty from the airfoil data alone somewhat improved quantitative estimates for a given configuration were obtainable by basing the estimates on the measured characteristics for a wing of similar plan form but different section and adjusting for the effects of differences in section on the basis of section data
CRAN	a correlation of airfoil section data with the aerodynamic loads measured on a 45 sweptback wing at subsonic mach numbers a correlation of airfoil section data with the aerodynamic loads measured on a 45 sweptback wing at subsonic mach numbers an investigation has been made of the possibility of correlating airfoil section data with measured pressure distributions over a 45 sweptback wing in the mach number range from 0 50 to 0 95 at a free stream reynolds number of approximately 2 million the wing had an aspect ratio of 5 5 a taper ratio of 0 53 naca 64a010 sections normal to the quarterchord line and was mounted on a slender body of revolution at mach numbers of 0 85 and below and for wing normal force coefficients below the maximum normal force coefficient for an infinite aspect ratio wing yawed 45 to the flow derived from airfoil section data by simple sweep relations good correlation was obtained over most of the wing between wing section and two dimensional airfoil pressure distributions for greater normal force coefficients lateral boundary layer flow permitted the inboard wing sections to rise to high maximum section normal force coefficients the effectiveness of this lateral boundary layer flow disappeared towards the tip for all mach numbers the influence of plan form effects on the pressure distributions limited the quality of the correlation at the 20  and 95 percent semispan stations above a mach number of about 0 85 the shock waves originating at the juncture of the body and the wing trailing edge spread over the span preventing further application of two dimensional data the spanwise load distributions at moderate normal force coefficients could be predicted from span loading theory for the entire mach number range of the tests
CRAN	the applications of the polygon method to the calculation of the compressible subsonic flow round two dimensional profiles the applications of the polygon method to the calculation of the compressible subsonic flow round two dimensional profiles this paper sets out the method now used by the author of applying the polygon method to the calculation of the compressible subsonic flow round two dimensional aerofoils tables have been constructed which can be used for all aerofoil shapes putting the polygon method on the same footing numerically as goldsteins method has the advantage over approximation 3 that it can be applied in the following cases which are beyond the scope of goldsteins method conventional aerofoils b the low speed flow about very thick aerofoils e g in reference 3 it is applied to circular cylinders c the flow about symmetric aerofoils between either straight or constant pressure walls d flow in asymmetric channels and e more difficult problems of the flow about aerofoils in the presence of one or two constraining walls to be published a method of calculating lift and moment coefficients and their rates of change with incidence a is also given in the paper as an example the velocity distribution and the rates of change of the lift and moment coefficients with a are calculated for the aerofoil r a e 104 at values of m mach number at infinity of 0 and 0 7 for various values of the incidence a the velocity distributions for zero incidence are found to be in fair agreement with the corresponding experimental results the results at incidence are in satisfactory agreement with the experimental results not for the same incidence but for the same lift coefficient it is found for example that at m 0 7 the theory for a 0 8 agrees best with experiment for a 1 0 when the lift coefficients are approximately the same
CRAN	laminar boundary layer oscillations and transition on a flat plate laminar boundary layer oscillations and transition on a flat plate this is an account of an investigation in which oscillations were discovered in the laminar boundary layer along a flat plate these oscillations were found during the course of an experiment in which transition from laminar to turbulent flow was being studied on the plate as the turbulence in the wind stream was being reduced to unusually low values by means of damping screens the first part of the paper deals with experimental methods and apparatus measurements of turbulence and sound and studies of transition a description is then given of the manner in which oscillations were discovered and how they were found to be related to transition and then how controlled oscillations were produced and studied in detail the oscillations are shown to be the velocity variations accompanying a wave motion in the boundary layer this wave motion having all the characteristics predicted by a stability theory based on the exponential growth of small disturbances a review of this theory is given the work is thus experimental confirmation of a mathematical theory of stability which had been in the process of development for a period of approximately 40 years mainly by german investigators
CRAN	the hall effect in the viscous flow of ionized gas between parallel plates under transverse magnetic field the hall effect in the viscous flow of ionized gas between parallel plates under transverse magnetic field the electrical conductivity of an ionized gas is anisotropic in the presence of magnetic field hall effect the conductivity is expressed by a tensor in the same form for both fully and partially ionized gases by the use of modified ohms law and conventional magnetohydrodynamical equations the incompressible viscous flow between parallel plates under the transverse magnetic field is analyzed and an exact solution is obtained when the magnetic reynolds number is small the numerical results reveal a remarkable effect of anisotropy of conductivity the acceleration and deceleration of viscous ionized gas under combined electric and magnetic fields are also calculated
CRAN	boundary layer induced noise in the interior of aircraft boundary layer induced noise in the interior of aircraft at high speeds the turbulent boundary layer washing the airplane fuselage excites appreciable skin vibration promoting strong noise in the interior the fluctuating exciting pressure distribution can be represented as a pattern of moving waves fourier integral a running ripple in the skin follows underneath each wave and the noise is ultimately due to these ripples the acoustic effects of the running ripples are calculated for an infinite sheet this is considered the main result of the paper supersonically moving ripples radiate strong sound in the form of mach waves subsonically moving ripples radiate no sound formulas for the mean square surface pressure and the energy flux are obtained for an assumed idealized turbulent pressure spectrum the results are adapted to provide a tentative estimate of the noise generated at subsonic speeds in a practical fuselage the running ripples are almost noise free but multiple reflections at the frames and stringers promote standing waves an assumption is used to link the two kinds of waves and this leads to provisional calculations of noise level on this basis the noise level is predicted to vary as for thin boundary layers changing progressively to for thick layers external air density speed layer thickness panel thickness some comparisons are made with experiment finally an idea for minimizing the noise is presented
CRAN	propeller in yaw propeller in yaw it was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin in 1917 r g harris expressed this force in terms of the torque coefficient for the unyawed propeller of several attempts to express the side force directly in terms of the shape of the blades however none has been completely satisfactory an analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of operating conditions is presented herein the present analysis shows that the fin analogy may be extended to the form of the side force expression and that the effective fin area may be taken as the projected side area of the propeller the effective aspect ratio is of the order of 8 and the appropriate dynamic pressure is roughly that at the propeller disk as augmented by the inflow the variation of the inflow velocity for a fixed pitch propeller accounts for most of the variation of side force with advance diameter ratio v nd the propeller forces due to an angular velocity of pitch are also analyzed and are shown to be very small for the pitching velocities that may actually be realized in maneuvers with the exception of the spin further conclusions are a dual rotating propeller in yaw develops up to one third more side force than a single rotating propeller a yawed single rotating propeller experiences a pitching moment in addition to the side force the pitching moment is of the order of the moment produced by a force equal to the side force acting at the end of a lever arm equal to the propeller radius this cross coupling between pitch and yaw is small but possibly not negligible the formulas for propellers in yaw derived herein with the exception of the compressibility correction and a series of charts of the side force derivative calculated therefrom have been presented without derivation in an earlier report
CRAN	effect of slight blunting of leading edge of an immersed body on the flow around it at hypersonic speed effect of slight blunting of leading edge of an immersed body on the flow around it at hypersonic speed manufacturing and maintainance of ideally sharp leading edges and noses is practically impossible hence a discrepancy arises between the theory established for sharp edges and actual flow around slightly blunted edges where a detached shock is formed with a subsonic adjacent region semi empirical method is worked out showing that the pressure distribution in the vicinity of the leading edge is the same for different thin profiles having the same shape of bluntness on their edges or noses the data for a flat plate can be used for all of them for moderate supersonic speed the pressure on the remaining body is practically unaffected by the nose bluntness and can be computed from a sharp edge theory for high supersonic speed a slight blunting of the edge can considerably alter the pattern of flow over a large region the method consists in replacing blunted edge by action of concentrated forces on the flow it is applied to blunted wedge where it shows doubling of the drag computed by classic theory and to cones where the drag of a blunted cone may become smaller than that of a sharp one
CRAN	theory and tunnel tests of rotor blade for supersonic turbines theory and tunnel tests of rotor blade for supersonic turbines in special circumstances where a large work output is required from a turbine in a single stage it is necessary to use high pressure ratios across the nozzle blades thus producing supersonic velocities at inlet to the rotor as part of an investigation into such turbines several designs for the inter blade passages of the rotor have been tested in a two dimensional tunnel a design theory being developed concurrently the first design featuring constant passage width and curvature as in steam turbine practice but having thin leading and trailing edges was found to suffer from focusing of the compression waves from the concave surface with consequent flow separation from the opposite convex surface it gave a velocity coefficient of measured at an inlet mach number of 1 90 and turning angle of 140 deg the measured value compares favourably with values from previous steam tests where the results have been in the range from 0 65 to 0 92 from theoretical reasoning and from additional test observations a subsequent passage was designed having an inlet transition length of small curvature leading to a free vortex passage of double the transition curvature a small amount of contraction was incorporated schlieren photographs showed the flow in this passage to be almost shock free a thin region of low energy air existed close to the convex surface but liquid injection tests located only one small bubble of reversed flow pressure traverses at exit indicated a velocity coefficient of 0 952 based on the area mean total pressure when allowance is made for turning angle and reynolds number this result appears to compare quite favourably with previous work it would seem that the optimum blade pitching in a turbine would be about 20 to 30 per cent closer than in a two dimensional cascade however the resultant pitching tends to become very close except at very large turning angles with the result that in some applications difficulties could arise in the practical design and manufacture several uncertainties remain and the present design must be regarded as still experimental
CRAN	the performance of supersonic turbine nozzles the performance of supersonic turbine nozzles an investigation has been conducted at the national gas turbine establishment into the performance of turbines having high pressure ratios per stage the present report discusses the mode of operation of supersonic nozzles for such turbines and describes a cascade experiment both theory and experiment demonstrate that the conditions imposed upon the supersonic flow immediately downstream of the nozzles e g by a following row of rotor blades exert an overriding influence upon the nozzle outlet flow angle and hence upon the maximum pressure ratio obtainable across the nozzle  providing that the axial component of velocity is subsonic this is an important difference from the more familiar flow of subsonic turbine nozzles where for example the downstream gas angle is controlled predominantly by the nozzle blade shape and spacing a suitable test technique using a closed jet tunnel is demonstrated the particular nozzles tested of convergent divergent form had a straight sided divergent portion of to axial direction and a design mach number of 2 the flow was found to be well behaved as regards shock pattern losses and starting over the range of pressure ratios tested  between 9 1 and 19 1 in particular the efficiency at the design pressure ratio of 16 6 1 was high the velocity coefficient calculated from traverses of pitot and static tubes being 0 98 for the conversion of pitot to total pressure at a mach number of 2 5 a high accuracy is important in the measurement of the static pressure nevertheless readings from a conventional four hole instrument appear to be reliable
CRAN	on the testing of supersonic compressor cascades on the testing of supersonic compressor cascades to facilitate the development of high speed axial flow compressors an investigation was made into the possibility of measuring blade performance in a stationary cascade at supersonic speeds a suitable technique was developed and the losses in a variety of cascades were measured but these losses were too high for the blading to have any possible application it was concluded that if a useful compressor is to result it is essential to test the cascades at mach numbers close to the existing technique was suitable only for zero incidence tests and thus a new approach is necessary some of the fundamentals of this cascade testing at low supersonic speeds are discussed in the light of the current understanding of the mode of operation of supersonic compressors at transonic speeds
CRAN	the test performance of highly loaded turbine stages designed for high pressure ratio the test performance of highly loaded turbine stages designed for high pressure ratio a blade design for a highly loaded two stage turbine is described and the test performance of the turbine is presented some of the factors affecting the performance and matching of turbine blade rows operating at supersonic gas velocity are discussed and investigated by means of tests on a three dimensional nozzle cascade tunnel and on a variety of single stage turbine builds
CRAN	the supersonic axial flow compressor the supersonic axial flow compressor an investigation has been made to explore the possibilities of axial flow compressors operating with supersonic velocities into the blade rows preliminary calculations showed that very high pressure ratios across a stage together with somewhat increased mass flows were apparently possible with compressors which decelerated air through the speed of sound in their blading the first phase of this investigation which has been reported in naca acr l5d20 was the development of efficient supersonic diffusers to decelerate air through the speed of sound the present report is largely a general discussion of some of the essential aerodynamics of single stage supersonic axial flow compressors in the supersonic flow about isolated bodies large energy losses usually occur due to wave systems which extend far from the bodies supersonic flow entering a cascade is considered and in this case the possibility of entirely eliminating this extended wave system is demonstrated thus no reason for supersonic compressors to be necessarily inefficient is apparent the conditions that occur as the flow through the compressor is being started are discussed and a hypothesis as to the type of transonic flow which will be encountered is proposed as an approach to the study of supersonic compressors three possible velocity diagrams are discussed briefly because of the encouraging results of this study an experimental single stage supersonic compressor has been constructed and tested in freon 12 in this compressor air decelerates through the speed of sound in the rotor blading and enters the stators at subsonic speeds a pressure ratio of about 1 8 at an efficiency of about 80 percent has been obtained
CRAN	flow pattern in a converging diverging nozzle flow pattern in a converging diverging nozzle the present report describes a new method for the prediction of the flow pattern of a gas in the two dimensional and axially symmetrical case it is assumed that the expansion of the gas is adiabatic and the flow stationary the several assumptions necessary on the nozzle shape effect in general no essential limitation on the conventional nozzles the method is applicable throughout the entire speed range the velocity of sound itself plays no singular part the principal weight is placed on the treatment of the flow near the throat of a converging diverging nozzle for slender nozzles formulas are derived for the calculation of the velocity components as function of the location
CRAN	intensity scale and spectra of turbulence in mixing region of free subsonic jet intensity scale and spectra of turbulence in mixing region of free subsonic jet the intensity of turbulence the longitudinal and lateral correlation coefficients and the spectra of turbulence in a 3 5 inch diameter free jet were measured with hot wire anemometers at exit mach numbers from 0 2 to 0 7 and reynolds numbers from the results of these measurements show the following 1 near the nozzle distances less than 4 or 5 jet diam downstream of the nozzle the intensity of turbulence expressed as percent of core velocity is a maximum at a distance of approximately increasing mach and or reynolds number at distances greater than 8 jet diameters downstream of the nozzle however the maximum intensity moves out and decreases in magnitude until the turbulence intensity profiles are quite flat and approaching similarity 2 the lateral and longitudinal scales of turbulence are nearly independent of mach and or reynolds number and in the mixing zone near the jet vary proportionally with distance from the jet nozzle 3 farther downstream of the jet the longitudinal scale reaches a maximum and then decreases approximately linearly with distance 4 near the nozzle the lateral scale is much smaller than the longitudinal and does not vary with distance from the centerline while the longitudinal scale is a maximum at a distance from the centerline of about mum moves out from the centerline 6 a statistical analysis of the correlograms and spectra yields a scale which although different in magnitude from the conventional varies similarly to the ordinary scale and is easier to evaluate
CRAN	on the strength distribution of noise sources along a jet on the strength distribution of noise sources along a jet the spatial distribution of noise sources along a jet is investigated by application of lighthills theory to regions of similar profiles the analysis refers to the noise power emitted by a slice of jet section between two adjacent planes normal to the axis as a function of distance x of the slice from the nozzle it is found that this power is essentially constant with x in the initial mixing region x law then further downstream say 8 or 10 diameters from the nozzle falls off extremely fast x law or faster in the fully developed jet because of this striking attenuation of strength with distance it is concluded that the mixing region produces the bulk of the noise and must dominate in muffler behavior conversely the fat part of the jet must contribute much less to the total noise power than is commonly supposed powells experiments on the effects of nozzle velocity profile on total noise power are interpreted qualitatively the behavior of multiple nozzle or corrugated mufflers both as to overall quieting and frequency shifting is also interpreted in the light of the results the possibility emerges that such mufflers may be improved without serious thrust loss by the addition of a sound attenuating shroud
CRAN	a general purpose analogue correlator for the analysis of random noise signals a general purpose analogue correlator for the analysis of random noise signals a large proportion of the current research programme of the department of aeronautics and astronautics is concerned with the study of jet noise and boundary layer pressure fluctuations and their effect on aircraft structures early in the work it was decided that for a complete description of the random processes involved it would be necessary in the experimental programme to make correlation measurements in addition to the more standard spectrum and amplitude distribution measurements it was also felt that it would be desirable from the university point of view to construct a general purpose correlator which could later be used on other types of work to this end it was decided to give the correlator a wider bandwidth than might strictly have been necessary for the problems on hand subsequent development work has amply justified this decision
CRAN	a theoretical study of annular supersonic nozzles a theoretical study of annular supersonic nozzles this paper is concerned with the design of annular supersonic nozzles to produce uniform flow in supersonic wind tunnels which are axi symmetrical and which have an internal coaxial circular cylinder throughout symmetrical two dimensional and conventional axi symmetrical nozzles are special cases of annular nozzles proposals are made for design criteria sufficient to ensure that the flow inside a nozzle is free from limit lines and shock waves the criteria for symmetrical two dimensional and conventional axi symmetrical nozzles are new the two outstanding procedures for designing two dimensional and axi symmetrical nozzles are generalised to apply to annular nozzles one of the design procedures is mainly analytical and the other is mainly numerical the analytical expressions in both procedures are made much more complicated by the presence of the internal cylinder but the numerical process criteria and the mainly numerical design procedure are successfully applied to the design of a particular annular nozzle
CRAN	the flow over delta wings at low speeds with leading edge separation the flow over delta wings at low speeds with leading edge separation a low speed investigation of the flow over a 40 apex angle delta wing with sharp leading edges has been made in order to ascertain details of the flow in the viscous region near the leading edge of the suction surface of the wing a physical picture of the flow was obtained from the surface flow and a smoke technique of flow visualization combined with detailed measurements of total head dynamic pressure flow directions and vortex core positions in the flow above the wing surface pressure distributions were also measured and integrated to give normal force coefficients the results of this investigation were compared with those of other experimental investigations and also with various theoretical results in particular the normal force coefficients vortex core positions and attachment line positions were compared with the theoretical results of mangler and smith reference 19 it was found that exist on the upper surface of the wing outboard of and below the main vortices these secondary vortices are formed as a result of separation of the boundary layers developing outboard of the top surface attachment lines
CRAN	a note on the theory of the stanton tube a note on the theory of the stanton tube existing theories for the stanton tube are critically reviewed and the paper then outlines a simple method which predicts the calibration function at high reynolds numbers to the right order of magnitude
CRAN	quasi cylindrical surfaces with prescribed loadings in the linearised theory of supersonic flow quasi cylindrical surfaces with prescribed loadings in the linearised theory of supersonic flow a formula for the velocity field in terms of a given surface distribution of vorticity is applied to points lying on the surface an equation giving the shape of a quasi circular cylindrical surface in terms of a prescribed loading is derived as an example a half ring wing with prescribed loading is discussed
CRAN	elliptic cones alone and with wings at supersonic speeds elliptic cones alone and with wings at supersonic speeds to help fill the gap in the knowledge of aerodynamics of shapes intermediate between bodies of revolution and flat triangular wings force and moment characteristics for elliptic cones have been experimentally determined for mach numbers of 1 97 and sectional axis ratios from 1 through 6 and with lengths and base areas equal to circular cones of fineness ratios 3 67 and 5 have been studied for angles of bank of 0 and 90 elliptic and circular cones in combination with triangular wings of aspect ratios 1 and 1 5 also have been considered the angle of attack range was from 0 to about 16 and the reynolds number was 8x10 based on model length in addition to the forces and moments at angle of attack pressure distributions for elliptic cones at zero angle of attack have been determined the results of this investigation indicate that there are distinct aerodynamic advantages to the use of elliptic cones with their major cross sectional axes horizontal they develop greater lift and have higher lift drag ratios than circular cones of the same fineness ratio and volume in combination with triangular wings of low aspect ratio they also develop higher lift drag ratios than circular cones with the same wings for winged elliptic cones this increase in lift drag ratio results both from lower zero lift drag and drag due to lift visual flow studies indicate that because of better streamlining in the crossflow plane vortex flow is inhibited more for an elliptic cone with major axis in the plane of the wing than for a circular cone with the same wing as a result vortex drag resulting from lift is reduced shifts in center of pressure with changes in angle of attack and mach number are small and about the same as for circular cones comparisons of theoretical and experimental force and moment characteristics for elliptic cones indicate that simple linearized flat plate wing theory is generally adequate even for relatively thick cones zero lift pressure distributions and drag can be computed using van dykes second order slender body theory for winged circular cones a modification of the slender body theory of naca rep 962 results in good agreement of theory with experiment
CRAN	aerofoil theory of a flat delta wing at supersonic speeds aerofoil theory of a flat delta wing at supersonic speeds lift drag and pressure distribution of a triangular flat plate moving at a small incidence at supersonic speeds are given for arbitrary mach number and aspect ratio the values obtained for lift and drag are compared with the corresponding values obtained by strip theory the possibility of further applications of the analysis leading up to the above results is indicated
CRAN	a technique for improving the predictions of linearised theory on the drag of straight edge wings a technique for improving the predictions of linearised theory on the drag of straight edge wings the curve of drag against mach number for straight edged wings calculated by using the linearised theory of supersonic flow displays discontinuities in slope at the various mach numbers for which the edges are sonic these features which are not observed in practice are due to the fact that linearised theory predicts an infinite pressure along a subsonic or sonic edge it is shown that if the linearised equation of supersonic flow is used to determine the flow over straight edged wings but the linearised boundary condition is replaced by the full placed by plausible values on this basis a simple method is derived for improving the linearised predictions of the drag of straight edged wings which exhibits satisfactory agreement with experimental results while the technique is not directly applicable to ridge lines an artifice renders them amenable to similar treatment
CRAN	navier stokes solutions at large distances from a finite body navier stokes solutions at large distances from a finite body this paper is concerned with a theoretical investigation of the flow field at large distances from an object moving through a viscous fluid the discussion will be restricted to the case of two dimensional stationary incompressible flow the object will be assumed to be of finite size the domain of the fluid is infinite and it is assumed that there are no other boundaries for the fluid except that of the given object the reynolds number will be assumed to have a fixed value thus we shall not consider the limiting cases of the reynolds number tending to zero or to infinity
CRAN	interference between the wings and tail surfaces of a combination of slender body cruciform wings and cruciform tail set at both incidence and yaw interference between the wings and tail surfaces of a combination of slender body cruciform wings and cruciform tail set at both incidence and yaw the interference between the wings and the tail surfaces of a combination of circular body low aspect ratio cruciform wings and cruciform tail in an inviscid flow is analysed using the slender body theory the system may be subjected to both incidence and yaw and in general the tail fins may be staggered angularly with respect to the main wings the method is a development of that used by owen and maskell in r a e report no aero 2441 to analyse similar effects on a system set at zero yaw simple expressions to determine the strengths and positions of the trailing vortices supposed to be rolled up downstream of the main wings are given and from them the forces on the tail are deduced when the tail surfaces are triangular and of low aspect ratio an exact solution is obtained from slender body theory but for rectangular tail surfaces of moderate or high aspect ratio it is suggested that the changes in lift and sideforce on the tail caused by the wing vortex field can be estimated approximately from the mean upwash and sidewash angles evaluated over the respective tail spans formulae for these means angles are presented
CRAN	interference between the wings and tail plane of a slender wing body tailplane combination interference between the wings and tail plane of a slender wing body tailplane combination an approximate method of predicting the interference between the wings and the tailplane of a slender wing body tailplane combination in an inviscid flow is developed in order to explain the change in centre of pressure position with incidence which has been found to occur in wind tunnel and flight tests on guided weapons incidence changes in one plane only normal to the plane containing the wings and the tail surfaces have been considered the method is based on slender body theory and the assumption that the wing trailing vortices roll up completely before they reach the tailplane it is therefore applicable to weapons equipped with low aspect ratio wings far separated from the tail surfaces when the tail surfaces are triangular and of low aspect ratio an analytical solution is given for the effect of the wing downwash field on the tail lift for high aspect ratio rectangular tail surfaces it is suggested by comparison with experimental data that the tail lift may be estimated approximately from the value of the mean downwash angle across the tail span a summary of the method is given in para 5 which in conjunction with the introduction may be read independently of the rest of the report
CRAN	practical calculation of second order supersonic flow past non lifting bodies of revolution practical calculation of second order supersonic flow past non lifting bodies of revolution calculation of second order supersonic flow past bodies of revolution at zero angle of attack is described in detail and reduced to routine computation use of an approximate tangency condition is shown to increase the accuracy for bodies with corners tables of basic functions and standard computing forms are presented the procedure is summarized so that one can apply it without necessarily understanding the details of the theory a sample calculation is given and several examples are compared with solutions calculated by the method of characteristics
CRAN	accuracy of approximate methods for predicting pressure on pointed non lifting bodies of revolution in supersonic flow accuracy of approximate methods for predicting pressure on pointed non lifting bodies of revolution in supersonic flow the accuracy and range of applicability of the linearized theory second order theory tangent cone method conical shock expansion theory and newtonian theory for predicting pressure distributions on pointed bodies of revolution at zero angle of attack are investigated pressure distributions and integrated pressure drag obtained by these methods are compared with standard values obtained by the method of characteristics and the theory of taylor and maccoll three shapes cone ogive and a modified optimum body are investigated over a wide range of fineness ratios and mach numbers it is found that the linearized theory is accurate only at low values of the hypersonic similarity parameter number to body fineness ratio and that second order theory appreciably extends the range of accurate application the second order theory gives good results on ogives when the ratio of the tangent of maximum surface angle to the tangent of the mach angle is less than 0 9 tangent cone method cannot be widely applied with good accuracy in general the conical shock expansion theory predicts pressure and drag within engineering accuracy when the hypersonic similarity parameter is greater than 1 2 although newtonian theory gives good accuracy except for cones at the highest values of the hypersonic similarity parameter investigated it is less accurate than the conical shock expansion theory
CRAN	the theoretical wave drag of some bodies of revolution the theoretical wave drag of some bodies of revolution this report investigates the wave drag of bodies of revolution with pointed or open nose forebodies and pointed or truncated afterbodies the quasi cylinder and slender body theories are reviewed a reversibility theorem is established and the concept of the interference effect of a forebody on an afterbody is introduced the theories are applied to bodies whose profiles are either straight or parabolic arcs formulae and curves being given for forebody and afterbody drag and for the interference drag the results of the two theories are compared and are seen to agree well in the region of geometries where both theories are applicable
CRAN	a second order shock expansion method applicable to bodies of revolution near zero lift a second order shock expansion method applicable to bodies of revolution near zero lift a second order shock expansion method applicable to bodies of revolution near zero lift is developed expressions defining the pressures on noninclined bodies are derived by the use of characteristics theory in combination with properties of the flow predicted by the generalized shock expansion method this result is extended to inclined bodies to obtain expressions for the normal force and pitching moment derivatives at zero angle of attack the method is intended for application under conditions between the ranges of applicability of the second order potential theory and the generalized shock expansion mehtod   namely when the ratio of free stream mach number to nose fineness ratio is in the neighborhood of 1 for noninclined bodies the pressure distributions predicted by the second order shock expansion method are compared with existing experimental results and with predictions of other theories for inclined bodies the normal force derivatives and locations of the center of pressure at zero angle of attack predicted by the method are compared with experimental results for mach numbers from 3 00 to 6 28 fineness ratio 7 5 and 3 cones and tangent ogives were tested alone and with cylindrical afterbodies up to 10 diameters long in general the predictions of the present method are found to be in good agreement with the experimental results for non inclined bodies pressure distributions predicted with the method are in good agreement with existing experimental results and with distributions obtained with the method of characteristics for inclined bodies the normal force derivatives per radian for normal force coefficients referenced to body base area are predicted within 0 2 and the locations of the center of pressure are predicted within 0 2 body diameters on the basis of these results the second order shock expansion method appears applicable for values of the ratio of free stream mach number to nose fineness ratio from 0 4 to 2
CRAN	on the minimisation and numerical evaluation of wave drag on the minimisation and numerical evaluation of wave drag a fourier analysis of the linearised theory expression for the zero lift wave drag of a smooth slender body in terms of its cross sectional area distribution is used to derive the area distribution which minimises the expression for given length volume nose area base area and n intermediate areas another minimal deduced from this by relaxing the restriction on volume is used to evolve a method for the numerical evaluation of the original expression two practical applications of these results are discussed the first is in the design of wing body combinations to have small drag rise at transonic speeds the second is in the calculation of the wave drag of wing body combinations at zero lift an example is constructed to illustrate the method and to give an indication of its accuracy
CRAN	criteria for thermodynamic equilibrium in gas flow criteria for thermodynamic equilibrium in gas flow when gases flow at high velocity the rates of internal processes may not be fast enough to maintain thermodynamic equilibrium by defining quasi equilibrium in flow as the condition in which the temperature pressure density and velocity deviate by less than a fixed small percentage from what they would be if the flowing gas could actually be in thermodynamic equilibrium criteria are derived for determining whether quasi equilibrium is a stable condition in the flow by use of excitation of molecular vibration as an example the general properties of criteria curves are discussed and interpreted a discussion is given of how to use these results to determine definitely whether a flow is or is not in thermodynamic equilibrium applications to dissociating gases to mixtures and to the phenomenon of choking in a laval nozzle are given special consideration for cases when application of the criteria predict nonequilibrium equations are provided in a form useful for numerical forward integration along streamlines
CRAN	a compressor routine test code a compressor routine test code the routine testing of aircraft type compressors dash in the main axial flow multi stage compressors dash requires a compromise between research accuracy and the practical considerations this test code is the outcome of a survey of compressor testing techniques and instrumentation initiated and subsequently discussed and endorsed by the aerodynamics sub committee of the gas turbine collaboration committee the code aims at defining methods of measurement and weighting whereby compressor performance can be obtained sufficiently accurately for a realistic and direct comparison to be made between one compressor and another the measurement of a quantity at a point in the fluid flow and the averaging and weighting of such measurements have been treated separately as far as is possible the recommendations are given in the main text whilst additional discussion on these is put into the appendices
CRAN	on a determination of the pitot static tube factor at low reynolds numbers with special reference to the measurement of low air speeds on a determination of the pitot static tube factor at low reynolds numbers with special reference to the measurement of low air speeds reasons for enquiry  to provide a standard instrument for the calibration of low speed anemometers
CRAN	design and calibration at low speeds of a static tube and a pitot static tube with semi ellipsoidal nose shapes design and calibration at low speeds of a static tube and a pitot static tube with semi ellipsoidal nose shapes a new static tube and a new pitot static tube have been designed and calibrated in the no 1 and the no 2 11 ft x 8 ft wind tunnels of the r a e using a long static tube the error of which is believed to be very small as a standard for comparison the results show that the static pressure measured by these tubes is in error due to the supporting strut and to the nose shape of the tube by an amount which may be calculated for positions of the static slot or holes greater than 10 tube diameters ahead of the strut the readings show no measurable scale effect in the speed range 100 230 ft sec the static tube is insensitive to yaw in the range 1 with a square edged slot and is even less sensitive to yaw when the slot edges are rounded the turbulence of the tunnel has an effect on the static pressure reading
CRAN	a theoretical analysis of heat transfer in regions of separated flow a theoretical analysis of heat transfer in regions of separated flow the flow field analyzed consists of a thin constant pressure viscous mixing layer separated from a solid surface by an enclosed region of low velocity air dead air the law of conservation of energy is employed to relate calculated conditions within the separated mixing layer to the rate of heat transfer at the solid surface this physical speed is app ied to alminar separations in compressible flow for various prandtl numbers including consideration of the case where air is injected into the separated region
CRAN	laminar mixing of a non uniform stream with a fluid at rest laminar mixing of a non uniform stream with a fluid at rest a theoretical analysis is made of the constant pressure laminar mixing process between a stream having an initial boundary layer velocity profile and a fluid at rest the present theory follows the methods of w tollmien and s i pai with certain modifications the results apply to incompressible flow but can be extended to the compressible case without difficulty
CRAN	an approximate theory of base pressure in two dimensional flow at supersonic speeds an approximate theory of base pressure in two dimensional flow at supersonic speeds an approximate theory of the base pressure in two dimensional flow at supersonic speeds is presented using asimplified representation of the flow and some of the findings of tollmiens work on turbulent mixing in incompressible flow good qualitative predictions of the effects of a boundary layer of bleed air and of boat tailing are obtained
CRAN	investigation with an interferometer of the turbulent mixing of a free supersonic jet investigation with an interferometer of the turbulent mixing of a free supersonic jet the free turbulent mixing of a supersonic jet of mach number of which a description is given was used for the investigation density and velocity distributions through the mixing zone have been obtained it was found that there was similarity in distribution at the cross sections investigated and that in the subsonic portion of the mixing zone the velocity distribution fitted the theoretical distribution for incompressible flow it was found that the rates of spread of the mixing zone both into the jet and into the ambient air were less than those of subsonic jets
CRAN	an improved smoke generator for use in the visualisation of airflow particularly boundary layer flow at high reynolds numbers an improved smoke generator for use in the visualisation of airflow particularly boundary layer flow at high reynolds numbers and rapid method by which boundary layer flow was rendered visible has been previously described in the journal of the royal aeronautical society it gave promise of being useful at the highest tunnel speeds provided a denser smoke could be obtained which at the same time was free from the troublesome deposits associated with the wood smoke of the aerodynamics division attempts were made by the fuel research station to improve the density of the wood smoke and to reduce the deposits these they showed were conflicting requirements and whilst some improvement was effected it was not sufficient for observation in the new tunnels at high speeds the staff of the director general of scientific research and development ministry of supply was then approached and it was decided to develop an oil smoke generator from a simple generator of this type which was demonstrated to us this has been done successfully the final apparatus in contrast to the wood smoke generator is light and compact it takes only a few minutes to start and can be run as long as desired improvement on the wood smoke both as regards density and freedom from deposits which cause premature transition the density and quality of the smoke are now under control smokes ranging from a light smoke of bluish white colour to a heavy smoke dense white in appearance can be obtained the oil smoke retains the advantages of the wood smoke in that it is non corrosive and non irritant and the smell can be tolerated even when it is present in a considerable concentration a certain amount of condensation is inevitable with oil smokes but with suitable precautions troubles arising from this can be avoided a dry solid smoke made by melting a hard wax was successfully generated with the same apparatus unfortunately because of its flocculent nature this smoke gave rise to solid deposits when passed through bore tubing leading eventually to complete blockage this seems to be a feature of solid smokes the apparatus has been used to determine transition and laminar separation points on model wings in a number of the national physical laboratory tunnels smoke filaments have been maintained in the laminar state up to wind speeds of 180 ft sec in the new tunnels there is much to be said for making a standard practice of visualising boundary layer flow on models particularly as the technique is simple and rapid it would greatly assist the interpretation of force measurements and the more detailed explorations of the boundary layer by total head tubes and hot wires the use of oil smoke is not limited to boundary layer flow visualisation the apparatus described in this report would seem to be particularly suited for educational work in small demonstration tunnels
CRAN	the ground effect on the jet flap in two dimensions the ground effect on the jet flap in two dimensions this paper presents the results of the first part of an experimental investigation of the ground effect on simple jet flap aerofoils in this part of the work an aerofoil having a 58 1 deg jet flap was tested under two dimensional conditions the pressure lift on the aerofoil was measured with the ground at fixed positions for varying jet momentum coefficients it was found that the effect of the ground on the pressure lift was very small up to a certain critical jet coefficient on increasing the jet coefficient beyond the critical value a marked loss of pressure lift was observed this critical value referred to is approximately the same as the jet coefficient at which the jet first hits the ground some significant though highly tentative comments are made regarding the practical application of this work to the take off characteristics of a jet flapped aircraft
CRAN	the design of minimum drag tip fins with an appendix   on the conformal transformation of a wing with a fin the design of minimum drag tip fins with an appendix   on the conformal transformation of a wing with a fin the report describes an investigation into the design of minimum drag tip fins by lifting line theory the work is based on an exact solution of the conformal transformation which is applicable to this problem following the method of trefitz three types of solution are treated corresponding to symmetrical upper and lower fins single upper or lower fins and unequal upper and lower fins a representative range of solutions for circulation distribution along wing and fins has been calculated for each of the three cases by the use of elliptic and theta functions a detailed account is given with examples of the procedure for calculating the plan of wing and fins the lift and induced drag and the setting of the fins
CRAN	the calculation of the pressure distribution on thick wings of small aspect ratio at zero lift in subsonic flow the calculation of the pressure distribution on thick wings of small aspect ratio at zero lift in subsonic flow the method of expressing the velocity increment over aerofoils directly in terms of the section ordinates wings of finite aspect ratio the wings considered are untapered in plan form but may be tapered in thickness the section can be of any given shape so that in this sense the analysis is more general than that of refs 3 to 6 which deal with wings of biconvex section the coefficients required in the calculation are tabulated for the centre section of straight and swept back wings of aspect ratios 0 5 1 2 and 4 the wing of infinite aspect ratio having been treated in ref 1 the remaining calculations can be made very quickly since wings of very small aspect ratio can be treated also by the method of slender body theory the relations between linear theory slender body theory and linearised slender body theory are discussed for the special case of ellipsoids the results obtained from the various methods are compared with the exact solution
CRAN	the application of lighthill formula for numerical calculation of pressure distributions on bodies of revolution at supersonic speed and zero angle of attack the application of lighthill formula for numerical calculation of pressure distributions on bodies of revolution at supersonic speed and zero angle of attack an integral expression given by lighthill and based on linearized theory for the external supersonic flow over the surface of slender pointed or ducted bodies of revolution at zero angle of attack is shown to give a good approximation of the exact flow for a much wider mach number and thickness range than could be expected from linearized theory a numerical method based on this expression is developed and applied for digital computing some results from applying the digital computing procedure for determining the pressure distribution and wave drag for various bodies of revolution are given
CRAN	formulae for the computation of the functions employed for calculating the velocity distribution about a given aerofoil formulae for the computation of the functions employed for calculating the velocity distribution about a given aerofoil in order to determine the velocity distribution about an arbitrary aerofoil it is necessary to evaluate the functions and in the notation of aerofoil theory when is given numerically if the values of are specified at 2n points equally spaced about the circle into which the aerofoil is transformed the formulae obtained here may be used to calculate these functions at the same points formulae are also given for calculating the integrals of or since these have application to the design of aerofoils by thwaitess numerical method the simplicity of the formulae for and enables the effect on the velocity distribution of a local change of shape readily to be determined by making n large this is discussed in 3 the formulae are collected in the appendix and a table of the coefficients for the case n 20 is given
CRAN	pressure distributions at zero lift for delta wings with rhombic cross sections pressure distributions at zero lift for delta wings with rhombic cross sections the linearised theory of thin wings is used to calculate pressure distributions over delta wings with rhombic cross sections a deuce programme has been written for the calculation and some of the results are compared with those of slender thin wing theory
CRAN	a collection of longitudinal stability derivatives of wings at supersonic speeds a collection of longitudinal stability derivatives of wings at supersonic speeds a collection has been made of theoretical data for wings alone on those stability derivatives that govern the short period oscillation of aircraft travelling at supersonic speeds all the derivatives available have been obtained by means of the linear theory and so the information given is subject to the usual limitations the information has been presented in what is hoped is the most convenient form to show its extent and to expose the parts of the field where experimental investigation is most needed
CRAN	an investigation of interference effects on similar models of different size in various transonic tunnels in the u k an investigation of interference effects on similar models of different size in various transonic tunnels in the u k details are given of a programme of tests being made on similar swept wing models in transonic tunnels of different types force measurement results at subsonic speeds in the r a e 3 ft by 3 ft slotted tunnel show only small interference effects for models of moderate blockage at low incidence at higher incidences the interference effect on lift becomes appreciably greater than estimated by theory and significant pitching moment differences occur apparently due to wall interference on the wing flow field comparable but smaller effects are evident in the results from the a r a 9 ft by 8 ft perforated tunnel at speeds just above m 1 the force fluctuates as speed is increased because of wave reflection interference the magnitude of the fluctuations diminishes as speed is further increased and this reduction is more marked in the perforated tunnel pressure measurements along the top of the body at zero incidence show delay in shock movements at high subsonic speeds indicating a blockage effect on speed the effect is larger in the perforated tunnel though smaller than predicted by theory above m 1 both expansion and shock waves are strongly reflected in the slotted tunnel but considerable alleviation particularly of shock waves is achieved in the perforated tunnel for which an analysis of the effects is given showing for example the effect of the open area distribution of the walls
CRAN	on the ground level disturbance from large aircraft flying at supersonic speeds on the ground level disturbance from large aircraft flying at supersonic speeds the whitham walkden theory for the estimation of the strength of shock waves at ground level from aircraft flying at supersonic speeds is applied to the case of a typical projected supersonic civil transport aeroplane if a figure of 2 lb sq ft including a factor of 2 for ground reflection is taken as an upper limit for the acceptable strength of the bow wave from such an aircraft it is shown that restrictions on the climb and flight plan will be involved the advantage of the employment of larger engines with or without afterburning is discussed with reference also to the penalties involved owing to the increase in weight of the aircraft and its direct operating costs finally it is suggested that an aircraft of given volume could be designed by suitable choice of thickness and lift distribution to minimise the strength of the shock waves in the far field
CRAN	boundary layers with suction and injection a review of published work on skin friction boundary layers with suction and injection a review of published work on skin friction available data on the effects of suction and injection on skin friction are summarised and compared it is shown that injection into a turbulent boundary layer can produce a skin friction coefficient lower than the laminar value at the same reynolds number on an impermeable plate
CRAN	an approximate solution of the turbulent boundary layer equations in incompressible and compressible an approximate solution of the turbulent boundary layer equations in incompressible and compressible if over the outer region of the boundary layer where the mean velocity varies but little from its value outside the shear layer a virtual eddy viscosity is defined which is constant over the outer region but varies in the direction of the mainstream a solution of the turbulent boundary layer equations can be found which satisfies the appropriate boundary conditions the solution leads to a compatibility condition for the virtual eddy viscosity in terms of the wall shear stress the boundary layer momentum thickness and the mainstream velocity at least for the case of a constant external velocity this compatibility condition which can be expressed as for moderate to high reynolds numbers where is the shear velocity is the boundary layer thickness and is the virtual eddy kinematic viscosity is just the condition townsend 1956 found for the equilibrium of the large eddies the numerical value of the constant derived by townsend agrees with ours for reynolds numbers based on x of about with this relation for an equation analoguous to the momentum integral equation solution can be found for as a function of local freestream velocity with one disposable parameter
CRAN	an experimental study of the glancing interaction between a shock wave and a turbulent boundary layer an experimental study of the glancing interaction between a shock wave and a turbulent boundary layer an experimental study has been made at mach numbers from 1 6 to 2 0 of the interaction between the turbulent boundary layer on a side wall of a wind tunnel and the shock wave produced by a plate mounted on the wall under these conditions the shock wave boundary layer interaction was three dimensional at least over the region investigated up to 10 boundary layer thicknesses from the plate it was found that the boundary layer was separated by a shock wave of strength type occur on the sides of fuselages at the wing fuselage junction and may therefore be important with regard to the design of waisted shapes
CRAN	on turbulen flow between parallel plates on turbulen flow between parallel plates the reynolds equations of motion of turbulent flow of incompressible fluid have been studied for turbulent flow between parallel plates the number of these equations is finally reduced to two one of these consists of mean velocity and correlation between transverse and longitudinal turbulent velocity fluctuations only the other consists of the mean pressure and transverse turbulent velocity intensity some conclusions about the mean pressure distribution and turbulent fluctuations are drawn these equations are applied to two special cases one is poiseuille flow in which both plates are at rest and the other is couette flow in which one plate is at rest and the other is moving with constant velocity the mean velocity distribution and the correlation can be expressed in a form of polynomial of the co ordinate in the direction perpendicular to the plates with the ratio of shearing stress on the plate to that of the corresponding laminar flow of the same maximum velocity as a parameter these expressions hold true all the way across the plates i e both the turbulent region and viscous layer including the laminar sublayer these expressions for poiseuille flow have been checked with experimental data of laufer fairly well it also shows that the logarithmic mean velocity distribution is not a rigorous solution of reynolds equations
CRAN	the effect of turbulence on slider bearing lubrication the effect of turbulence on slider bearing lubrication based on prandtls mixing length mechanism the pressure equation for turbulent flow in slider bearing lubrication is derived an analytical solution is given and compared with the one for laminar flow it is found that the turbulent effect increases the pressure and consequently the load carrying capacity however the power loss also increases
CRAN	second order theory for unsteady supersonic flow past slender pointed bodies of revolution second order theory for unsteady supersonic flow past slender pointed bodies of revolution the thermodynamic properties z pv rt e rt h rt s r and pressure are given for equilibrium mixtures of dissociated and ionized molecules and atoms of the elements nitrogen and oxygen having the low temperature composition of 78847 n and 21153 o the tabulated properties of this mixture a close approximation to the properties of air are given at close intervals from 2000 to and 10 times the normal density the results are based on chemical equilibria between the species o o n n no no no no o o o o n n n and electrons the method of presentation permits later corrections for the effect of argon and co and the contribution of intermolecular forces the calculations are based on 9 758 e v as the dissociation energy of molecular nitrogen and 1 45 e v as the electron affinity of atomic oxygen
CRAN	a critical review of skin friction and heat transfer solutions of the laminar boundary layer of a flat plate a critical review of skin friction and heat transfer solutions of the laminar boundary layer of a flat plate a review is made of existing literature concerned with the analytical investigation of the velocity and temperature distributions in the boundary layers of a heated or cooled flat plate the plate is postulated infinitely thin and is parallel to a uniform fluid stream the more recent solutions include the combined effects of frictional dissipation and variable fluid properties only the results pertaining to the transfer phenomena occurring at the plate surface are included i e skin drag and over all heat transfer the individual temperature and velocity distributions leading to these results are omitted
CRAN	experiments on axi symmetric boundary layers along a long cylinder in incompressible flow experiments on axi symmetric boundary layers along a long cylinder in incompressible flow experiments on axi symmetric boundary layers along a long cylinder were made especially to investigate the effect of transverse curvature on the velocity profile laminar velocity profiles were measured and compared with theoretical ones with good accuracy a representative profile was plotted to see the effect of transverse curvature which showed small but obvious effect accompanied by increasing skin friction the transition of the flow from laminar to turbulent was observed and its reynolds number was estimated to occur at 1 2 1 8x10 in the present experiment the turbulent profile was also measured and plotted by using the coordinates to express the wall law deduced by richmond from which it was estimated that as the ratio of the momentum thickness to body radius increases the profile near the outer layer tends to bend down relative to the line of logarithmic wall law
CRAN	the formation of a blast wave by a very intense explosion the formation of a blast wave by a very intense explosion this paper was written early in 1941 and circulated to the civil defence research committee of the ministry of home security in june of that year the present writer had been told that it might be possible to produce a bomb in which a very large amount of energy would be released by nuclear fission  the name atomic bomb had not then been used  and the work here described represents his first attempt to form an idea of what mechanical effects might be expected if such an explosion could occur in the then common explosive bomb mechanical effects were produced by the sudden generation of a large amount of gas at a high temperature in a confined space the practical question which required an answer was would similar effects be produced if energy could be released in a highly concentrated form unaccompanied by the generation of gas qm this paper has now been declassified and though it has been superseded by more complete calculations it seems appropriate to publish it as it was first written without alteration except for the omission of a few lines the addition of this summary and a comparison with some more recent experimental work so that the writings of later workers in this field may be appreciated an ideal problem is here discussed a finite amount of energy is suddenly released in an infinitely concentrated form the motion and pressure of the surrounding air is calculated it is found that a spherical shock wave is propagated outwards whose radius r is related to the time t since the explosion started by the equation where is the atmospheric density e is the energy released and s a calculated function of the ratio of the specific heats of air the effect of the explosion is to force most of the air within the shock front into a thin shell just inside that front as the front expands the maximum pressure decreases till at about 10 atm the analysis ceases to be accurate at 20 atm 45 of the energy has been degraded into heat which is not available for doing work and used up in expanding against atmospheric pressure this leads to the prediction that an atomic bomb would be only half as efficient as a blast producer as a high explosive releasing the same amount of energy in the ideal problem the maximum pressure is proportional to r and comparison with the measured pressures near high explosives in the range of radii where the two might be expected to be comparable shows that these conclusions are borne out by experiment
CRAN	cylindrical shock waves produced by instantaneous energy release cylindrical shock waves produced by instantaneous energy release taylors analysis of the intense spherical explosion has been extended to the cylindrical case it is found that the radius r of a strong cylindrical shock wave produced by a sudden release of energy e per unit length grows with time t according to the equation where is the atmospheric density and is a calculated function of the specific heat ratio for is found to be approximately unity for this case the pressure behind the shock wave decays with radius r according to the relation applying the results of this analysis to the case of hypersonic flight it can be shown that the shock envelope behind a meteor or a high speed missile is approximately a paraboloid given by where d and v denote the total drag and the velocity of the missile respectively and x is the distance behind the missile
CRAN	asymptotic solution of the two dimensional oscillating aerofoil problem for high subsonic mach numbers asymptotic solution of the two dimensional oscillating aerofoil problem for high subsonic mach numbers a new method has been given for obtaining asymptotic solutions of a boundary value problem for the wave equation the method is simpler than the method previously given by burger and leads to a result identical with burgers result
CRAN	some instabilities arising from the interaction between shock waves and boundary layer some instabilities arising from the interaction between shock waves and boundary layer a brief review is made of the available information concerning the flow fluctuations and instabilities arising from shock induced separation in the flow over aerofoils and wings the influence this phenomenon has on the oscillatory behaviour of aerofoils and control surfaces is also briefly discussed a more detailed consideration is devoted to a recent investigation at the n p l into the part played by shock induced separation in the instability of a control surface
CRAN	exact solution of the neumann problem calculation for non  circulatory plane and axially symmetric flows about or within arbitrary boundaries exact solution of the neumann problem calculation for non  circulatory plane and axially symmetric flows about or within arbitrary boundaries an exact general method of solving the neumann or second boundary value problem has been developed and has been applied to the calculation of low speed flows about or within bodies of almost any shape provided the flow is either plane or has axial symmetry solid body inlet and purely internal flow problems can be solved the method is capable of dealing with several bodies at once in the presence of one another and consequently interference problems can be treated with ease boundaries need not be solid that is flows involving area suction can be calculated velocities can be computed not only for points on the surface of the body but for the entire flow field a surface source distribution is used as a basis for solution this leads to a fredholm integral equation of the second kind which is solved as a set of linear algebraic equations usually by a modified seidel method at the present time the solution is programed on the ibm 704 edpm to solve the flow about any body that has the previously mentioned characteristics and whose profile can be defined satisfactorily by no more than 300 coordinate points a number of solutions are presented to show both the scope of the method and its accuracy computations require from three minutes to two hours depending upon the shape of the body and the number of points used to define it
CRAN	steady and transient free convection of an electrically conducting fluid from a vertical plate in the presence of a magnetic field steady and transient free convection of an electrically conducting fluid from a vertical plate in the presence of a magnetic field an analysis is made for the laminar free convection and heat transfer of a viscous electrically conducting fluid from a hot vertical plate in the case when the induced field is negligible compared to the imposed magnetic field it is found that similar solutions for velocity and temperature exist when the imposed magnetic field acting perpendicular to the plate varies inversely as the fourth root of the distance from the lowest end of the plate explicit expressions for velocity temperature boundary layer thickness and nusselt number are obtained and the effect of a magnetic field on them is studied it is found that the effect of the magnetic field is to decrease the rate of heat transfer from the wall in the second part the method of characteristics is employed to obtain solutions of the time dependent hydromagnetic free convection equations hyperbolic of momentum and energy put into integral form the results yield the time required for the steady flow to be established and the effect of the magnetic field on this time is studied
CRAN	several magnetohydrodynamic free convection solutions several magnetohydrodynamic free convection solutions the influence of transverse magnetic fields on the laminar free convection flow of liquid metals over a vertical flat plate and between vertical parallel plates is examined for specific wall temperature variations and prandtl numbers the extent of influence on the flow and temperature fields is determined by the magnitude of a nondimensional influence parameter which is the ratio of the magnetic force to the buoyant force in general increasing the magnetic field strength decreases the magnitude of the velocity wall shear and surfaces heat transfer and increases the temperature throughout the fluid analytical results demonstrate that magnetic fields of practical strengths exert considerable influence on liquid metal free convection flow fields
CRAN	on a laminar free convection flow and heat transfer of electrically conducting fluid on a vertical flat plate in the presence of a transverse magnetic field on a laminar free convection flow and heat transfer of electrically conducting fluid on a vertical flat plate in the presence of a transverse magnetic field the free convection flow and heat transfer of an electrically conducting fluid on a vertical plate in the presence of a transverse magnetic field is analysed for a magnetic field fixed to the electrically non conducting wall the boundary layer equations for self preserving flows are integrated numerically for the prandtl number of unity and the effect of the transverse magnetic field on the velocity profile temperature profile and rate of heat transfer is discussed it is concluded that the heat transfer rate is reduced as the magnetic field intensity is increased
CRAN	on combined free and forced convection laminar magnetohydrodynamic flow and heat transfer in channels with transverse magnetic field on combined free and forced convection laminar magnetohydrodynamic flow and heat transfer in channels with transverse magnetic field combined free and forced convective heat transfer in vertical channels has been studied by many researchers due to the need for engineering design information there have been many papers concerning cases of fully developed flow with varying wall temperature forced flows in a channel of electrically conducting fluid with a transverse magnetic field have been studied and the large effects of a magnetic field on the flow pattern have been established flows of combined free and forced convection in electrically conducting fluids in vertical channels with a transverse magnetic field are expected to attract attention in future engineering applications for example in a magneto hydrodynamic generator or in plasma studies however except for a report by gershuni and zhukhovitskii 1 concerning a particular case no general study has been published this paper is a general treatment of fully developed free and forced convective laminar magneto hydrodynamic flow in a vertical channel with a transverse magnetic field it includes combined free and forced convective flows in channels without a magnetic field reported by ostrach 2 tao 3 etc as special cases hartmann flow 4 is included in the other limit
CRAN	an experimental test of compressibility transformation for turbulent boundary layer an experimental test of compressibility transformation for turbulent boundary layer discussion of various turbulent boundary layer theories in the light of experimental measurements by matting and co workers the application of 1 the mager insulated wall transformation and and illustrated graphically
CRAN	oscillatory aerodynamic coefficients for a unified supersonic hypersonic strip theory oscillatory aerodynamic coefficients for a unified supersonic hypersonic strip theory the shock tube is shown to be a feasible research tool for conducting boundary layer transition experiments the use of the shock tube permits the study of transition with highly cooled boundary layers as may be encountered on hypersonic vehicles boundary layer transition investigations have been made on optically polished pyrex hemisphere cylinder and ellipse cylinder models with stagnation to wall enthalpy ratios between 4 5 and roughness estimated to be less than 1 microinch rms transition was detected by measurements of the heat transfer rates on the model surface the shock tube experiments indicated that a characteristic feature of transition of a highly cooled boundary layer on a hemisphere was the simultaneous occurrence of transition over the entire supersonic portion of the hemisphere this implies that transition first occurred in the sonic region the transition reynolds number based on local fluid properties at the outer edge of the boundary layer and the momentum thickness in the sonic region increased from about 225 to 325 as the stagnation  to wall enthalpy ratio increased from about 9 5 to 29 5 transition occurred along the cylindrical portion of the hemisphere cylinder model at a nearly constant momentum thickness reynolds number increasing from about 400 to 625 as the stagnation  to wall enthalpy ratio increased from about 9 5 to 29 5 the highly cooled boundary layers obtained on the cylindrical portion of the shock tube hemisphere cylinder model provided an extension of nasa transition results obtained on a cooled hemisphere cone cylinder model in a wind tunnel the transition reynolds numbers obtained from these shock tube data were of the same order of magnitude as the minimum transition reynolds numbers obtained in the wind tunnel experiments the results indicate that for practical purposes boundary layer cooling is not a critical transition parameter for blunt bodies with a highly cooled boundary layer resulting from a stagnation  to wall enthalpy ratio of about 3 to 30 that is the transition reynolds number did not vary significantly with boundary  layer cooling in this cooling range but transition always occurred at a low reynolds number between about 350 000 and 750 000 based on local external properties and a distance along the body surface from the stagnation point the boundary layer history body shape history appeared to be an important parameter affecting the magnitude of the reynolds number for transition and the amount of increase in the transition reynolds number with increased boundary layer cooling that is transition occurred at a lower reynolds number on the ellipse cylinder configuration than on the hemisphere cylinder also the increase in transition reynolds number with an increase in boundary layer cooling was even less significant for the ellipse cylinder than the hemisphere cylinder
CRAN	flow past slender blunt bodies   a review and extension flow past slender blunt bodies   a review and extension a numerical solution of the inviscid flow field about slender blunt bodies of revolution has been developed through a combination of two methods the van dyke solution in the subsonic flow region at the nose and the method of characteristics in the supersonic region the results are compared with second order blast wave theory and with experimental data and the respective merits and deficiencies of the two theoretical methods are pointed out the results of the numerical solution are further used in a discussion of the entropy layer to propose a possible criterion of entropy layer thickness
CRAN	analysis of quartz and teflon shields for a particular re entry mission analysis of quartz and teflon shields for a particular re entry mission the transient performance of ablation type heat protection shields is treated herein for the surface of a vehicle returning from outer space to the earth the vehicle weighs 8640 kg has a ballistic factor of 500 lb ft re enters with a speed of 11 km sec at ratio of 0 5 and is subjected to a maximum deceleration of 7 7 times the gravity constant by use of well known equations for the heat transfer and the mass transfer at a heated surface a numerical calculation method is derived which for the investigated ablation processes yields exact transient solutions of the fundamental system of partial differential equations the method is applied to various quartz shields and to one teflon shield which all evaporate so readily under the conditions of the problem at hand that practically no flow of molten shield material exists the solutions also show comparatively small temperature changes parallel to the surface the results show that the nose of the vehicle is cooled predominantly by the evaporation of the quartz or the teflon the rest of the vehicles surface is cooled by radiation of the quartz or evaporation of the teflon the large mass transfer effects on the nose of the vehicle are detrimental since the resulting low surface temperatures prevent the radiative heat transfer out of the shield which does not involve any mass loss from being the desirable governing cooling factor
CRAN	the effect of lift on entry corridor depth and guidance requirements for the return lunar flight the effect of lift on entry corridor depth and guidance requirements for the return lunar flight corridors for manned vehicles are defined consistent with requirements for avoiding radiation exposure and for limiting values of peak deceleration use of lift increases the depth of the entry corridor mid course guidance requirements appear to be critical only for the flight path angle increasing the energy of the transfer orbit increases the required guidance accuracy for the flight path angle corrective thrust applied essentially parallel to the local horizontal produces the maximum change in perigee altitude for a given increment of velocity energy required to effect a given change in perigee altitude varies inversely with range measured from the center of the earth
CRAN	reaction tests of turbine nozzles for supersonic velocities reaction tests of turbine nozzles for supersonic velocities a machine for testing turbine nozzles by the reaction method which was described in a previous paper was used to test a series of convergent divergent turbine nozzles the results of these tests along with the test of a convergent turbine nozzle are compared with each other and with analytical values two kinds of analytical values are employed namely the usual values obtained from an assumed isentropic expansion from inlet state to exhaust pressure and the values obtained from the assumption that the processes in the nozzle are isentropic except for a normal shock which takes up a position in the nozzle such as to cause the stream to fill the exit area at the exhaust pressure whenever possible this latter kind of analytical value involves no shock when the exit area can be filled at the exhaust pressure by means of isentropic processes only or when the exhaust pressure is lowered so far that the shock has passed out of the passage the agreement of the test results with the calculated results of this latter kind is good and the disagreement which exists can be attributed largely to separation at the shock and to transmission of exhaust pressure effects upstream through the boundary layer
CRAN	study of flow conditions and deflection angle at exit of two dimensional cascade of turbine rotor blades at critical and supercritical pressure ratios study of flow conditions and deflection angle at exit of two dimensional cascade of turbine rotor blades at critical and supercritical pressure ratios an analysis was made of the flow conditions downstream of a cascade of turbine rotor blades at critical and supercritical pressure ratios the results of five theoretical methods for determining the deflection angle are compared with those of an experimental method using the conservation of momentum principle and static pressure surveys and also are compared with an analysis of schlieren photographs of the flow downstream of the blades a two  dimensional cascade of six blades with an axial width of 1 80 inches was used for the static pressure surveys and for some of the schlieren photographs in order to determine the flow conditions several blade chords downstream of the cascade schlieren photographs were taken of the flow through a cascade of 18 blades having an axial width of 0 60 inch for the blade design studied even at static to total pressure ratios considerably lower than that required to give critical velocity at the throat section the flow was deflected in the tangential direction as predicted for the incompressible case as the pressure ratio was lowered further the aerodynamic loading of the rear portion of the blade reached a maximum value and remained constant after this condition was attained the expansion downstream of the cascade took place with a constant tangential velocity so that no further increase in the amount of turning across the blade row and no further increase in the loading of the blade was available
CRAN	on source and vortex distributions in the linearised theory of steady supersonic flow on source and vortex distributions in the linearised theory of steady supersonic flow the hyperbolic character of the differential equation satisfied by the velocity potential in linearized supersonic flow entails the presence of fractional infinities in the fundamental solutions of the equation difficulties arising from this fact can be overcome by the introduction of hadamards finite part of an infinite integral together with the definition of certain counterparts of the familiar vector operators this leads to a natural development of the analogy between incompressible flow and linearized supersonic flow in particular formulae are derived for the field of flow due to an arbitrary distribution of supersonic sources and vortices applications to aerofoil theory including the calculation of the downwash in the wake of an aerofoil are given in a separate report ref 9
CRAN	supersonic drag calculations for a cylindrical shell wing of semicircular cross section combined with a central body of revolution supersonic drag calculations for a cylindrical shell wing of semicircular cross section combined with a central body of revolution a semi circular ring wing with a body of revolution on the axis is studied to find the wave and the vortex drag for various chordwise lift distributions and for three values of a parameter describing the wing geometry using the wave drag obtained from the chordwise loading that gives the least drag together with the vortex and skin friction drags the maximum lift to drag ratio for each wing geometry is computed compared to the estimates made by lomax and heaslet somewhat lower drags are found
CRAN	the surface oil flow technique as used in high speed wind tunnels in the united kingdom the surface oil flow technique as used in high speed wind tunnels in the united kingdom an examination has been made of the various versions of the surface oil flow technique used in different high speed wind tunnels to provide background information for this investigation some systematic tests were made on a simple model in a small supersonic tunnel the experience gained made it possible to explain many of the variations in terms of the different operating conditions of the tunnels the time taken to form a pattern on a typical model is to a first approximation directly proportional to the value of the parameter the factor being 36 000 12 000 the time taken appears to be independent of the initial thickness of the oil sheet a general procedure for the development of oil mixtures for any purpose is suggested
CRAN	higher order approximations for relaxation oscillations higher order approximations for relaxation oscillations the problem of solving asymptotic developments for all quantities involved in relaxation oscillations has been solved by haag this paper indicates how one can carry out such developments in a case which is simple enough to be treated explicitly
CRAN	jet effects on base pressure of conical afterbodies at mach 1 91 and 3 12 jet effects on base pressure of conical afterbodies at mach 1 91 and 3 12 data are presented which show the effect of a jet on base pressure for a series of conical afterbody jet nozzle combinations having boat tail angles that varied from 0 to 11 and base to jet diameter ratios that varied from 1 11 to 2 67 the jet nozzles had exit angles from 0 to 20 and were designed for exit mach numbers from 1 0 to 3 2 pressure ratios up to 30 were tested for both a cold air and a hot numbers of 1 91 and 3 12 in general base pressure increased for increasing values of boat tail angle nozzle angle jet temperature and jet total pressure and for decreasing values of base to jet diameter ratio jet mach number and free stream mach number the addition of tail surfaces produced only small changes in base pressure for all variables base pressure is governed by the maximum pressure rise that can be supported by the wake fluid in the region of the trailing shock the wake pressure ratio is in turn governed by the jet and free stream mach numbers adjacent to the wake region and by the state of the boundary layer on the boattail and on the nozzle values of wake pressure ratio computed using the theory of korst page and childs were in good agreement with experimental values for convergent nozzles
CRAN	laminar heat transfer around blunt bodies in dissociated air laminar heat transfer around blunt bodies in dissociated air a method of predicting laminar heat transfer rates to blunt highly cooled bodies with constant wall temperature in dissociated air flow is developed attention is restricted to the case of axisymmetric bodies at zero incidence although two dimensional bodies could be treated the same way the method is based on the use of the local similarity concept and an extension of the ideas used by fay and riddell a simple formula is given for predicting the ratio of local heat transfer rate to stagnation point rate it depends on wall conditions and pressure distribution but not on the thermodynamic or transport properties of the hot external flow except at the stagnation point experimental heat transfer rates obtained with correct stagnation point simulation and high wall cooling in shock tubes are also presented and compared with the theoretical predictions on the whole the agreement is good although in regions of rapidly varying pressure there is evidence that the local similarity assumption breaks down and the theory underestimates the actual heat transfer rate by up to 25 per cent
CRAN	the divergence of supersonic wings including chordwise bending the divergence of supersonic wings including chordwise bending the static aeroelastic stability or divergence problem is investigated for thin supersonic wings when not only the spanwise bending and twist are taken into account but also the chordwise bending the problem is treated in successive phases of increasing complexity from the two dimensional curling up of the leading edge to the three dimensional stability of the cantilever wing several methods of approach are developed including the nonlinear aspects of the structure and the aerodynamics results indicate a strong dependence of stability on poissons ratio and the magnitude of the deformation
CRAN	on the flutter of panels at high mach numbers on the flutter of panels at high mach numbers there have recently arisen some questions as to the possibility of panel flutter at high dynamic pressures and mach numbers in addition some doubts have been raised about the convergence of the galerkin method when applied to such problems this note is intended to shed light on these matters
CRAN	effect of roll on dynamic instability of symmetric missiles effect of roll on dynamic instability of symmetric missiles this note attempts to extend the discussion by stating a slightly neater form of generalized stability conditions and describing certain experimental results on dynamic instability
CRAN	some theoretical low speed loading characteristics of swept wings in roll and sideslip some theoretical low speed loading characteristics of swept wings in roll and sideslip the weissinger method for determining additional span loading for incompressible flow is used to find the damping in roll the lateral center of pressure of the rolling load and the span loading coefficients caused by rolling for wing plan forms of various aspect ratios taper ratios and sweep angles in addition the applicability of the method to the determination of certain other aerodynamic derivatives is investigated and corrections for the first order effects of compressibility are indicated the agreement obtained between experimentally and theoretically determined values for the aerodynamic coefficients indicates that the method of weissinger is well suited to the calculation of the additional span loading caused by rolling and for the calculation of such resulting aerodynamic derivatives of wings as do not involve considerations of tip suction
CRAN	the rolling up of the trailing vortex sheet and its effect on the downwash behind wings the rolling up of the trailing vortex sheet and its effect on the downwash behind wings the motion of the trailing vortices associated with a lifting wing is investigated by theoretical and visual flow methods for the purpose of determining the proper vortex distribution to be used for downwash calculations both subsonic and supersonic speeds are considered in the analysis it is found that the degree to which the vortices are rolled up depends upon the distance behind the wing and upon the lift coefficient span loading and aspect ratio of the wing while the rolling up of the trailing vortices associated with high aspect ratio wings is of little practical importance it is shown that with low aspect ratio wings the trailing vortex sheet may become essentially rolled up into two trailing vortex cores within a chord length of the trailing edge the downwash fields associated with the two limiting cases of the flat vortex sheet and the fully rolled up vortices are investigated in detail for both subsonic and supersonic speeds the intermediate case in which the rolling up process is only partially completed at the tail position is also discussed
CRAN	a theoretical study of the aerodynamics of slender cruciform wing arrangements and their wakes a theoretical study of the aerodynamics of slender cruciform wing arrangements and their wakes a theoretical study is made of some cruciform wing arrangements and their wakes by means of slender body theory the basic ideas of this theory are reviewed and equations are developed for the pressures loadings and forces on slender cruciform wings and wing body combinations the rolling up of the vortex sheet behind a slender cruciform wing is considered at length and a numerical analysis is carried out using 40 vortices to calculate the wake shape at various distances behind an equal span cruciform wing at 45 bank analytical expressions are developed for the corresponding positions of the rolled up vortex sheets using a 4 vortex approximation to the wake and these positions are compared with the positions of the centroids of vorticity resulting from the numerical analysis the agreement is found to be remarkably good at all distances behind the wing photographs of the wake as observed in a water tank are presented for various distances behind a cruciform wing at 0 and 45 bank for 45 bank the distance behind the wing at which the upper two vortices pass between the lower two is measured experimentally and is found to agree well with the the calculation of loads on cruciform tails is considered in some detail by the method of reverse flow and equations are developed for the tail loads in terms of the vortex positions calculated in the earlier analyses
CRAN	dynamic stability of a missile in rolling flight dynamic stability of a missile in rolling flight the paper sets down the equations of motion for a symmetric rolling missile with respect to axes attached to the missile the missile may be jet or rocket propelled or coasting under accelerating or decelerating conditions respectively wherein the variable rolling velocity is derived from intentionally or unintentionally canted fins and or wings the equations contain a force and moment system that includes in addition to the usual forces and moments those due to magnus effects misaligned surfaces canted surfaces jet misalignment and the linear accelerations in the plane normal to the missile axis the results present general stability criteria for a rolling missile which are summarized in the discussion of stability
CRAN	sweepback effects in the turbulent boundary layer shock wave interaction sweepback effects in the turbulent boundary layer shock wave interaction experiments are reported on the interaction of turbulent boundary layers and shock waves with sweptback configurations they show that the peak pressure rise at separation the upstream influence ahead of separation and the pressure rise at reattachment for moderate sweep angles can all be understood by simple extensions of available two dimensional theories
CRAN	rapid laminar boundary layer calculations by piece wise application of similar solutions rapid laminar boundary layer calculations by piece wise application of similar solutions a method is presented for the rapid calculation of the incompressible laminar boundary layer in an arbitrary flow around either a two dimensional or a rotationally symmetrical body the solution is obtained without recourse to von karmans momentum equation by means of a coarse step by step procedure in which each segment of the velocity distribution is approximated by one of the falkner skan family of similar flows solutions have at least as much accuracy as those of any other one parameter approximate method and in certain cases the solutions become exact in regions of accelerating velocity the accuracy appears to be very high in decelerating flows separation is predicted somewhat early compared with exact solutions that is the method is conservative in contrast to the von karman pohlhausen procedure which sometimes fails to predict separation that actually exists the method is the most rapid hand procedure known to the author provided the full history of the boundary layer is required if only a thickness such as is needed at one point on a surface then it is about equal in speed to the quadrature method but if several values of or other properties along a surface are required it is appreciably faster than the quadrature method characteristically only four steps are needed between the forward stagnation point and the pressure peak once the velocity distribution data are available each step in a two dimensional calculation requires about 5 minutes using a slide rule
CRAN	recent studies on the effect of cooling on boundary layer transition at mach 4 recent studies on the effect of cooling on boundary layer transition at mach 4 the advent of high speed flight has necessitated the study of boundary layer transition on highly cooled bodies investigations such as those of references 1 4 have concentrated on this problem and have indicated contrary to the trends predicted by small disturbance theory that premature transition can be found with cooling this phenomenon commonly called detail in references 2 5 the purpose of this note is to report some recent transition data obtained on a cooled cone in a mach 4 wind tunnel the model a sharp tip cone included angle 13 5 was cooled by liquid nitrogen to a temperature of  340 f the cooling method and the data analysis are similar to that described in reference 3
CRAN	an investigation of laminar transitional and turbulent heat transfer on blunt nosed bodies in hypersonic flow an investigation of laminar transitional and turbulent heat transfer on blunt nosed bodies in hypersonic flow laminar transitional and turbulent heating rates have been measured by means of the shrouded model technique the reynolds number was varied over a ninefold range the enthalpy ratio stagnation to wall varied from 2 3 to approximately 1 5 two different pressure distributions were imposed on the model which consisted of a spherically capped cone the experimental data are compared to the laminar hypersonic boundary layer theory and shown to be in good agreement on the conical portion of the model on the spherical portion the data are approximately 20 per cent higher than the theoretical prediction some of this discrepancy can be attributed to radiation to the nose of the model the fully developed turbulent heat transfer data are compared to two theories 1 a relatively simple turbulent theory which is based on recent theoretical work and which takes into account the upstream history of the boundary layer and 2 the flat plate reference enthalpy theory which depends on only local conditions although both theories are in reasonable agreement with the data the latter method is simpler and somewhat more accurate for transitional flow the theory mentioned first can be readily modified in order to permit reasonable estimates of transitional heat transfer to be obtained on this basis it is possible to estimate laminar transitional and fully developed turbulent heat transfer under hypersonic blunt body conditions the behavior of transition reynolds number based on momentum thickness is also discussed and shown to be in quantitative agreement with recent shock tube measurements
CRAN	a note on transitional heat transfer under hypersonic conditions a note on transitional heat transfer under hypersonic conditions in references 1 and 2 there were presented experimental data on transitional heat transfer on a blunt body under hypersonic flow conditions obtained by the shroud technique the data were compared with a theoretical prediction of transitional heat transfer based on a suggestion of persh the agreement between theory and experiment in the transitional region was found to be qualitatively good and quantitatively fair it is the purpose of this note to present some additional transitional data obtained in conventional wind tunnel tests and to indicate a means for improving somewhat the agreement between transitional theory and experiment
CRAN	notes on waves through gases at pressures small compared with the magnetic pressure with applications to upper atmosphere aerodynamics notes on waves through gases at pressures small compared with the magnetic pressure with applications to upper atmosphere aerodynamics most treatments of magnetohydrodynamic waves have confined physical interpretation to cases when the alfven velocity a is small compared with the sound velocity a here we consider the low beta situation in which a is much larger than a then except for two modes with wave velocity a the only possible waves are longitudinal ones propagated unidirectionally along lines of magnetic force with velocity a these can be interpreted as sound waves confined to effectively rigid magnetic tubes of force hall current effects do not alter these conclusions in contrast to the high beta situation and finite conductivity introduces only small dissipation an application is made to the flow pattern around a body moving through the f layer of the ionosphere where although neutral particles have a very large mean free path charged particles interact electrostatically and it is argued may be regarded as forming a continuous fluid whose movement is independent of that of the neutral particles a body moving at satellite speed or below would then excite the above mentioned unidirectional sound waves but no waves at much faster alfven velocity these considerations suggest that its movement would be accompanied by a v shaped pattern of electron density figure 2 which might be in part responsible for some anomalous radar echoes that have been reported
CRAN	compressibility effects in magneto aerodynamic flows past thin bodies compressibility effects in magneto aerodynamic flows past thin bodies the effects of compressibility on the steady motion of a highly conducting fluid past thin cylindrical bodies in the presence of a magnetic field are studied procedures are developed for the solution of this class of magnetoaerodynamic problems over the entire mach number range and for all ratios of magnetic to fluid dynamic pressure the results obtained are analogous either to the ackeret theory or the prandtl glauert rule of conventional aerodynamics depending on the relative values of the flow speed and the appropriate speed of propagation of magnetoacoustic disturbances the methods used and the physical interpretation of the solutions obtained vary according to the orientation of the magnetic field with respect to the flow direction the results of the theory are explained in terms of the anisotropic propagation of magnetoacoustic pulses studied previously by several authors
CRAN	incompressible wedge flows of an electrically conducting viscous fluid in the presence of a magnetic field incompressible wedge flows of an electrically conducting viscous fluid in the presence of a magnetic field the purpose of this note is to discuss the two dimensional flow of an electrically conducting viscous fluid past a wedge in the presence of a magnetic field the governing differential equations and boundary conditions are given and analyzed
CRAN	magnetohydrodynamic flow past a semi infinite plate magnetohydrodynamic flow past a semi infinite plate the flow of viscous electrically conducting fluid past a semi infinite plate is considered the applied constant magnetic field and the constant on coming velocity of the fluid are in the direction parallel to the plate in addition to reynolds number the flow in the boundary layer depends on two parameters and the two simultaneous ordinary nonlinear differential equations are solved by the asymptotic method for the cases when and respectively the main results obtained are as follows the equations can be solved exactly for and the perturbation effect from infinity when k is large depends on whereas the perturbation effect from zero when k is small depends on for large k including there is no solution for it is assumed that the fluid is incompressible with constant physical properties
CRAN	on a particular class of similar solutions of the equations of motion and energy of a viscous fluid on a particular class of similar solutions of the equations of motion and energy of a viscous fluid by introducing the similarity concept to the two dimensional incompressible navier stokes equations and energy equation a particular class of solutions is found two general types of flows are considered 1 laminar free convection  i e flows which take place due to a body force  and 2 laminar forced convection for free convection on vertical plates similar solutions are obtained for two different power law surface temperature variations and it is shown that one of these solutions constitutes a new type of boundary problem results of numerical integrations of the equations are compared with solutions of the similar boundary layer equations for free convection and it is demonstrated that a range of surface temperature variations exists for which the boundary layer equations are no longer valid for forced convection it is shown that the use of similarity transformations provides an alternate method of deriving the ordinary differential equations for some well known solutions such as couette and stagnation point flows solutions are obtained for radial converging or diverging flows between plane surfaces when the temperatures of the surfaces vary as arbitrary powers of the distance from the orgin results of numerical integrations of the ordinary differential equations are presented for prandtl numbers of 0 01 and 1 0 and for linear surface temperature variations some rather surprising results are obtained for diverging flows when separation occurs and some revealing comparisons with results from boundary layer theory are made
CRAN	approximate design of sharp cornered supersonic nozzles approximate design of sharp cornered supersonic nozzles a modified parabolic curve appears to be in close proximity to that obtained by either the method of characteristics or the wave method thus an attempt has been made to use analytic geometry to determine approximately the contour of a two dimensional sharp cornered supersonic nozzle in a very short time
CRAN	approximations for the thermodynamic and transport properties of high temperature air approximations for the thermodynamic and transport properties of high temperature air the thermodynamic and transport properties of high temperature air are found in closed form starting from approximate partition functions for the major components in air and neglecting all minor components the compressibility enthalpy entropy the specific heats the speed of sound the coefficients of viscosity and of thermal conductivity and the prandtl numbers for air are tabulated from 500degree to 15 000degree k over a range of pressure from 0 0001 to 100 atmospheres the energy of air and the mol fractions of the major components of air can be found from the tabulated values for compressibility and enthalpy it is predicted that the prandtl number for fully ionized air which is in complete equilibrium will become small compared to unity the order of transparent to heat flux
CRAN	effect of variable heat recombination on stagnation point heat transfer effect of variable heat recombination on stagnation point heat transfer earlier studies assume an average heat of formation of atoms based upon external flow conditions it is shown that equilibrium heat transfer decreases by 35 for a typical mach number 24 case when allowance is made for the proportions of air components the variable recombination energy also results in atom mass fractions which are realistically less for equilibrium than frozen situations throughout the cold wall boundary layer
CRAN	first order approach to a strong interaction problem in hypersonic flow over an insulated flat plate first order approach to a strong interaction problem in hypersonic flow over an insulated flat plate the present paper concerns with the strong interaction phenomenon over an insulated semi infinite flat plate with a sharp leading edge in particular the main interest is in the consistent treatment in which the boundary layer solution may be joined continuously with the inviscid solution regarding flow variables including pressure normal velocity temperature or streamwise velocity and density it is shown that the behavior of the inviscid solution may be consistent with that of the boundary layer solution to at least first order approximation that is correct to the order of where m is the mach number of undisturbed flow r the reynolds number based on the distance from leading edge and the ratio of specific heats then the first order boundary layer problem is formulated under such an external circumstance and an attempt is made for arriving at the solution actual calculations are carried out for both cases of air and helium from the solution it is found that the region in which the viscous effect plays a significant role is ranged over from 0 to a certain finite value of n say n in terms of the similarity coordinate n in the corresponding incompressible boundary layer the numerical results moreover indicate that the induced pressure is considerably smaller than the estimate of lees 7 obtained by his approximate method in which the effect of the first order induced pressure on the boundary layer is ignored and no survey of the first order boundary layer equation is made the present results are also found to be in excellent agreement with experimental data recently obtained in helium flow by erickson 15
CRAN	hypersonic strong viscous interaction on a flat plate with surface mass transfer hypersonic strong viscous interaction on a flat plate with surface mass transfer the present report gives an account of the development of an approximate theory to the problem of hypersonic strong viscous interaction on a flat plate with mass transfer at the plate surface the disturbance flow region is divided into inviscid and viscous flow regions the hypersonic small perturbation theory is applied to the solution of the inviscid flow region the method of similar solutions of compressible laminar boundary layer equations is applied to the treatment of the viscous flow region the law of surface mass transfer for similar solutions is derived the pressure and the normal velocity are matched between the inviscid and viscous flow solutions formulas for induced surface pressure boundary layer thickness skin friction coefficient and heat transfer coefficient are obtained numerical results and their significance are discussed future improvements are indicated
CRAN	second approximation to laminar compressible boundary layer on flat plate in slip flow second approximation to laminar compressible boundary layer on flat plate in slip flow the first order solution for the laminar compressible boundary layer flow over a flat plate at constant wall temperature is given the effect of slip at the wall as well as the interaction between the boundary layer flow and the outer stream flow are taken into consideration the solution is obtained explicitly in terms of the known zero order or continuum solution no assumptions regarding the prandtl number or viscosity temperature law need be made it is found that the first order solution gives a decrease in heat transfer and for supersonic flow an increase in skin friction for subsonic flow there is no first order shear effect the change in heat transfer is due to slip and the change in friction is due to the interaction of the zero  and first order velocities at the outer edge of the boundary layer
CRAN	an approximate solution of hypersonic laminar boundary layer equations and its application an approximate solution of hypersonic laminar boundary layer equations and its application approximate formulae of the displacement thickness and the skin friction of the hypersonic laminar boundary layer are derived by use of von karmans integral method assuming the heat insulated wall the prandtl number of unity and chapman and rubesins formula for the variation of viscosity with temperature the results obtained are compared with some exact solutions because of the good agreement it seems that these formulae are very useful these formulae together with the tangent wedge approximation are applied to the viscous flow over slender bodies with a sufficiently sharp leading edge as an example the pressure distribution over a flat plate is calculated numerically over the entire region of the surface comparison with other authors theoretical results as well as experimental values is made
CRAN	on the hypersonic viscous flow past a flat plate with suction or injection on the hypersonic viscous flow past a flat plate with suction or injection the hypersonic viscous flow past a flat plate with suction or injection is dealt with by karman pohlhausens method in special cases when suction or injection velocity proportional to especially for the region of strong interaction between the shock wave and the boundary layer were p is the pressure on the plate and x is the distance measured along the plate from its leading edge several numerical examples are given which shows similar effects of injection to those in the case of incompressible flow that the injection makes all the height of the shock wave the thickness of the boundary layer and the pressure on the plate larger than those in the case of no injection on the contrary in the case of suction no remarkable change both in the height of the shock wave and the pressure on the plate can be seen and only the velocity profile in the boundary layer is affected by the suction
CRAN	on the motion of a flat plate at high speed in a viscous compressible fluid ii steady motion on the motion of a flat plate at high speed in a viscous compressible fluid ii steady motion the theory of the steady flow of a viscous compressible fluid past a flat plate at high mach number due to lees and probstein is extended by a more complete discussion of the flow in the inviscid layer between the shock wave and the boundary layer it is shown that similar solutions exist in this layer analogously to those found by li and nagamatsu in the boundary layer and that the two may be joined to give allowing one minor assumption a full account of the flow it is shown that the boundary layer equations may be reduced to those for an incompressible fluid and that the von karman pohlhausen method describes the flow in it with good accuracy the tangent wedge approximation for the pressure on the plate used by lees and his collaborators is found to be in deficit by 10 per cent for air finally it is shown that the theory for weak interaction cannot be extended further without a complete knowledge of the flow
CRAN	hypersonic viscous flow over a flat plate hypersonic viscous flow over a flat plate in dealing with the steady laminar viscous flow over a semi infinite flat plate some of the following topics are discussed the streamline in the boundary layer over a leading edge of given thickness the rate of growth of the boundary layer in the main stream and causes of pressure variations asymptotic solutions for thn downstream flow region including the joining interaction of shock waves at the leading edge pressure variations in the interanl viscous flow layer and in external inviscid flow considered as prandtl meyer flow in cases of streamline deflection the free stream mach number zero pressure gradient and surface pressure distribution asymptotic solutions for cases of fluid injection of a cool gas prandtl heat transfer the joining interaction between the external inviscid flow and the internal viscous flow layer steady laminar hpyersonic viscous flow over a flat wedge and a cone
CRAN	a method for predicting the onset of buffeting and other separation effects from wind tunnel tests on rigid models a method for predicting the onset of buffeting and other separation effects from wind tunnel tests on rigid models the method is based on the observation of the divergence that occurs in the variation of mean static pressure at the trailing edge of an aircraft wing at the critical stage in the development of boundary layer separation when its influence first spreads to the trailing edge and thereby to the overall flow the significance of the trailing edge pressure variations and their connection with the effects that separation has on the mean and unsteady loads is discussed for various types of separation good prediction can be obtained from wind tunnel tests or warning provided in flight for low speed separations and for shock induced ones up to the stage at which the shock wave reaches the trailing edge related divergences in wake width lift coefficient or shock position can also be used pressure measurements at other isolated points often indicate the type of separation certain special considerations apply for swept wings the various flow changes that are considered are illustrated by schlieren photographs and described in an appendix
CRAN	chordwise pressure distributions over several naca 16 series airfoils at transonic mach numbers up to 1 25 chordwise pressure distributions over several naca 16 series airfoils at transonic mach numbers up to 1 25 a two dimensional wind tunnel investigation of the pressure distributions over several naca 16 series airfoils with thicknesses of and design lift coefficients of the langley airfoil test apparatus at transonic mach numbers from 0 7 to number from 2 4 x 10 to 2 8 x 10 and in angle of attack from  10 to and schlieren flow photographs are presented without analysis
CRAN	on alternative forms for the basic equations of transonic flow theory on alternative forms for the basic equations of transonic flow theory attention has been called by numerous authors to the possibility of certain alternative forms for the equations for transonic flow about thin wings it is the purpose of this note to contribute to this discussion and to indicate some reasons for the selection of one form of these in preference to another more widely used form
CRAN	simplified method for determination of the critical height of distributed roughness particles for boundary layer transition at mach numbers from 0 to 5 simplified method for determination of the critical height of distributed roughness particles for boundary layer transition at mach numbers from 0 to 5 a simplified method has been devised for determination of the critical height of three dimensional roughness particles required to promote premature transition of a laminar boundary layer on models of airplanes or airplane components in a wind tunnel with zero heat transfer a single equation is derived which relates the roughness height to a reynolds number based on the roughness height and on local flow conditions at the height of the roughness and charts are presented from which the critical roughness height can be easily obtained for mach numbers from 0 to 5 a discussion of the use of these charts is presented with consideration of various model configurations the method has been applied to various types of configurations in several wind tunnel investigations conducted by the national advisory committee for aeronautics at mach numbers up to 4 and in all cases the calculated roughness height caused premature boundary layer transition for the range of test conditions
CRAN	scale effects at high subsonic and transonic speeds and methods for fixing transition in model experiments scale effects at high subsonic and transonic speeds and methods for fixing transition in model experiments the major scale effects at high subsonic and transonic speeds arise from differences between the conditions under which laminar and turbulent boundary layers separate and in how they behave after separation for turbulent boundary layers these conditions and behaviour do not vary greatly as the reynolds number is changed and in many examples it has been shown that they are similar for the turbulent layers that occur naturally at high reynolds number and for boundary layers in which transition to turbulent flow is fixed artificially the scale effects arising in wind tunnel tests made at low reynolds number may therefore often be minimised by fixing transition to turbulent flow by introducing an artificial disturbance such as that produced by excrescences attached to the surface the fact that the effects of separation are often less severe for laminar layers than for the turbulent layers that are likely to be encountered at full scale makes it all the more important to do this whenever possible several methods which can be used to fix transition are described and the results obtained by using them are compared in general in experiments in two dimensional flow good agreement is found and explanations can be advanced for cases in which discrepancies occur several uncertainties and difficulties that arise in fixing transition are discussed and illustrated by examples in particular special care is needed in interpreting the results obtained with transition fixed at very low reynolds numbers say less than about r 1 x 10 based on local chord for wings of about 0 1 thickness chord ratio and possibly higher reynolds numbers for thinner wings the difficulties of fixing transition satisfactorily are increased for three dimensional wings particularly if they are swept back or highly tapered i e small chord and reynolds number near the tip and if the tests cover a large range of incidence including high incidences for which the flow may separate from very close to the leading edge under these circumstances it is frequently necessary to place the excrescences at different chordwise positions for low and high angles of incidence and this is inconvenient in practice more research is needed before sound recommendations can be made as to how and where transition should be fixed on such models particularly since in routine testing it is often not possible to check the effects of transition fixing fully in the sections dealing with three dimensional tests examples are given of the spurious results that have been avoided successfully by fixing transition of the conditions where even at low reynolds numbers artificial fixing of transition may not be necessary to give a turbulent boundary layer ahead of the shock and of the conditions under which there are some doubts whether the methods used for fixing transition have been satisfactory
CRAN	the occurrence and development of boundary layer separations at high incidences and high speeds the occurrence and development of boundary layer separations at high incidences and high speeds this note describes the manner in which the onset of the effects of boundary layer separation varies with mach number for two dimensional aerofoils and discusses the influence of section shape as far as it is known a brief qualitative description is given of the mechanism underlying the development of the separated flow and its effects followed by a discussion of some of the ways in which this is likely to differ for swept back wings at high speeds finally the need is emphasized for continued work in a broadening field
CRAN	non equilibrium flow of an ideal dissociating gas non equilibrium flow of an ideal dissociating gas the theory of anideal dissociatinggas developed by lighthill 1957 for conditions of thermodynamic equilibrium is extended to non equilibrium conditions by postulating a simple rate equation for the dissociation process including the effects of recombination this equation contains theequilibriumparameters of the lighthill theory plus a further dissociation phenomena the behaviour of this gas is investigated in flow through a strong normal shock wave and past a bluff body the assumption is made that the gas receives complete excitation of its rotational and vibrational degrees of freedom in an infinitesimally thin region according to the familiar rankine hugoniot shock wave relations before dissociation begins the variation of the relevant thermodynamic variables down stream of this region is then computed in a few particular cases the method used in the latter case is an extension of thenewtoniantheory of hypersonic inviscid flow in particular the case of a sphere is treated in some detail the variation of the shock shape and the sphere diameter to the length scale of the dissociation process is exhibited for conditions extending from completely undissociated flow to dissociated flow in thermal equilibrium results would indicate that significant and observable changes from the undissociated values occur although values for the non equilibrium parameter are not at present available
CRAN	inviscid hypersonic flow past blunt bodies inviscid hypersonic flow past blunt bodies two methods are shown for the calculation of the flow field between a blunt body and the shock associated with it for the case of hypersonic flow real gas effects are included the solutions consider only symmetric flows  that is symmetric bodies at zero incidence one method consists in tracing successive stream tubes around the body and leads to iterations on the initially assumed position of the shock the second is an integral method closely analogous to the karman pohlhausen procedure for boundary layers a distinction is made between round nosed and flat nosed bodies and both cases are discussed a specific example corresponding to a re entry missile situation is calculated the two methods agree within a few per cent comparison is also made with other known solutions in the stagnation region
CRAN	propagation of weak disturbances in a gas subject to relaxation effects propagation of weak disturbances in a gas subject to relaxation effects a generalized wave equation is derived for sound disturbances in a gas when relaxation effects connected with for example molecular vibration or dissociation are important solutions involving discontinuous wave fronts are presented and it is shown that under certain assumptions the complete wave equation reduces to a variant of the telegraph equation detailed solutions are presented for disturbance fields produced by a wavy wall in subsonic and supersonic flow and a simple wedge in supersonic flow this study is viewed as a step in the development of a theory of small disturbances of a high temperature gas as is found behind the shock in hypersonic flight
CRAN	comment on improved numerical solution of the blasius problem with three point boundary conditions comment on improved numerical solution of the blasius problem with three point boundary conditions attention is drawn to a previous accurate solution to the problem
CRAN	improved numerical solution of the blasius problem with three point boundary conditions improved numerical solution of the blasius problem with three point boundary conditions the blasius equation describes the velocity distribution resulting from laminar constant pressure mixing of a stationary fluid layer and a moving stream in connection with a numerical procedure for the univac based on analytic continuation of the function f high speed computers now make it feasible to use analytic continuation for numerical integration of single point boundary value problems such that within the limits of taylors expansion truncation error may be made arbitrarily small a brief description of the application of the routine is given
CRAN	on the numerical solution of the blasius problem with three point boundary conditions on the numerical solution of the blasius problem with three point boundary conditions relates to a technique for approximate determination of the initial parameters the technique is an application of the asymptotic integration method introduced by meksyn and has been applied to the computation of the skin friction for shock generated boundary layer flow
CRAN	vorticity interaction at an axisymmetric stagnation point in a viscous incompressible fluid vorticity interaction at an axisymmetric stagnation point in a viscous incompressible fluid the purpose of the present note is to give an exact solution of the incompressible navier stokes equations at an axisymmetric stagnation point with vorticity in the oncoming flow which varies linearly with distance from the axis this solution has application to the hypersonic axisymmetric blunt body problem for which lighthill has shown the vorticity in the inviscid shock layer is very nearly of this form
CRAN	vorticity effect on the stagnation point flow of a viscous incompressible fluid vorticity effect on the stagnation point flow of a viscous incompressible fluid the effect of vorticity on axisymmetric stagnation point boundary layer calculations is investigated by calculating a perturbation to the stagnation point flow the shear caused by the vorticity effect is found to be surprisingly large the slope of the shear curve at zero vorticity as calculated by kemp agrees perfectly with the value deduced in this note
CRAN	heat transfer to constant property laminar boundary layer flows with power function free stream velocity and wall temperature variation heat transfer to constant property laminar boundary layer flows with power function free stream velocity and wall temperature variation numerical computations have been performed for the boundary layer form of the energy equation for incompressible flows with power function variation of free stream velocity u cx and of wall temperature t ax the pertinent solutions of the momentum equation in this case being those of hartree the numerical computations given herein are to some extent a repetition of those given by schuh and by chapman and rubesin the object of the present computations being the resolution of discrepancies appearing in the previous solutions and an extension of their range ibm machine calculations were employed in the finite difference calculation presently utilized the results thereof covering a range of wall temperature function exponents from values of m 4 1 0  0 0904 the accuracy of the numerical computations is examined in detail and the accuracy of the computed functions at the wall which determine the heat transfer rate is estimated to be within 2 per cent examination of the results reveals that the results of schuh for the flat plate are in error for the range of the calculations it was found that the local heat transfer coefficient can with the exception of large negative values be expressed within 5 per cent as where the exponent of the prandtl number varies from 0 254 to 0 367 for  0 0904 and where the function can be approximated by the equation
CRAN	forst order slip effects on the compressible laminar boundary layer over a slender body of revolution in axial flow forst order slip effects on the compressible laminar boundary layer over a slender body of revolution in axial flow analysis of the compressible boundary layer with transverse curvature in first order slip flow no boundary layer interaction effects are considered and only the zero pressure gradient case is examined
CRAN	on local flat plate similarity in the hypersonic boundary layer on local flat plate similarity in the hypersonic boundary layer a study is made of lees local flat plate similarity rule for the hypersonic laminar boundary layer it is shown that this rule is exact under assumptions commonly invoked in the inviscid theory of hypersonic flow beginning from this theoretical basis a modified local flat plate similarity scheme is derived involving separate rules for velocity and enthalpy profiles and is compared with exact similarity solutions and with the existing theory of hypersonic leading edge interaction
CRAN	the boundary layer near the stagnation point in hypersonic flow past a sphere the boundary layer near the stagnation point in hypersonic flow past a sphere flow properties behind shock waves caused by bluff bodies traveling at supersonic speeds are of major importance in missile and high speed aircraft design paper presents a mathematical solution for the laminar boundary layer near the stagnation point of a sphere surface temperature is free stream static and shock is strong air is assumed calorically and thermally perfect with a prandtl number of 0 72 and a dynamic viscosity directly proportional to temperature based on work of homann zamm 16 p 153 1936 and lighthill simultaneous differential equations for the velocity and temperature profiles these are solved by numerical integration along a normal to the surface using a digital computer results are presented as functions of free stream mach number reynolds number and specific heat ratio as increases boundary layer thickness is shown to decrease while shock stand off distance increases stand off distance also decreases with increasing and decreasing specific heat for constant and specific heat ratio the product of skin friction coefficient and the square root of decreases with increasing only approaching a constant value at greater than 10 000 reviewers comment is concerned with the perfect gas assumption for air author suggests that the effects of dissociation on flow properties are accounted for by a proper choice of specific heat ratio a consideration of the kinetics of chemical reaction in the cooled boundary layer emphasizes the oversimplification of this approach the effect on transport properties could have been approximated in present analysis by changing the prandtl number to one more representative of the existing pressures and temperatures
CRAN	various aerodynamic characteristics in hypersonic rarefied gas flow various aerodynamic characteristics in hypersonic rarefied gas flow this paper considers the problem of calculating viscous aerodynamic characteristics of blunt bodies at hypersonic speeds and at sufficiently high altitudes where the appropriate mean free path becomes too large for the use of familiar boundary layer theory but not so large that free molecule concepts apply results of an order of magnitude analysis are presented to define the regimes of rarefied gas flow and the limits of continuum theory based on theoretical and experimental evidence the complete navier stokes equations are used as a model except very close to the free molecule condition this model may not necessarily give the shock wave structure in detail but satisfies overall conservation laws and should give a reasonably accurate picture of all mean aerodynamic quantities in this intermediate regime there are two fundamental classes of problems a viscous layer class and a merged layer class the latter corresponding to a larger degree of rarefaction for the viscous layer class there is a thin shock wave but the shock layer region between the shock and the body is fully viscous although the viscous stresses and conductive heat transfer are small at the shock wave boundary here the use of the navier stokes equations with outer boundary conditions given by the hugoniot relations is justified for the merged layer class the shock wave is no longer thin and the navier stokes equations can be used to give a solution which includes the shock structure and has free stream conditions as outer boundary conditions a simpler procedure is presented for incipient merged conditions where the shock may no longer be considered an infinitesimally thin discontinuity but where it has not thickened sufficiently to entail the fully merged layer analysis in this case we approximate the shock by a discontinuity obeying conservation laws which include curvature effects viscous stresses and heat conduction for a sphere and cylinder it is shown that the navier stokes equations can be reduced to ordinary differential equations for both the viscous and merged layer class of problems solutions of these equations when used in connection with hypersonic flow problems are in general only valid in the stagnation region to illustrate the viscous layer solutions numerical calculations have been performed for a sphere and cylinder with the assumption of constant density in the shock layer which is a useful approximation at hypersonic speeds to illustrate the merged layer solution calculations have been carried out for a sphere using the incipient merged layer approximation results are presented for detachment distance surface shear and heat transfer rate in the stagnation region of a highly cooled sphere flying at hypersonic speed with decreasing reynolds number the shear and heat transfer are shown to increase above the extrapolated boundary layer values in the viscous layer regime and then to begin falling in the incipient merged regime as the reynolds number decreases in the incipient merged regime the density in the shock layer increases and the static and stagnation enthalpy behind the shock decrease calculations performed for an insulated sphere show that with decreasing reynolds number in the incipient merged regime the density in the shock layer decreases the total enthalpy behind the shock and at the stagnation point increase so that they are higher than the free stream total enthalpy and the stagnation point pressure behaves like the total enthalpy for the highly cooled cylinder in the viscous layer regime the same quantities are presented as for the sphere the increase found in shear and heat transfer above extrapolated boundary layer theory is small in agreement with vorticity interaction theory a discussion is given of the behavior of available experimental data for viscous flow quantities in the intermediate regime and the behavior predicted by the results of the present calculations qualitative agreement is indicated
CRAN	taylor instability of finite surface waves taylor instability of finite surface waves the instability of the accelerated interface between a liquid methanol or carbon tetrachloride and air has been investigated experimentally for approximate sinusoidal disturbances of wave number range from well below to well above the cut off the growth rates are measured and compared with theoretical results a third order theory shows the phenomena of overstability which is found in the experimental results some measurements of later stages of growth agree moderately well with the available theory and disclose some additional phenomena of bubble competition helmholtz instability with transition to turbulence and jet instability with production of drops
CRAN	effects of surface tension and viscosity on taylor instability effects of surface tension and viscosity on taylor instability the model used is that of two fluids of infinite depth with the interface initially in the form of a sine wave with amplitude small compared to wave length the fluids are considered incompressible and only the linear terms in the equations of hydrodynamics are used the first four sections discuss the effects of surface tension and viscosity the fifth gives a few numerical results to illustrate the main points of the preceding sections
CRAN	similitude of hypersonic real gas flows over slender bodies with blunted noses similitude of hypersonic real gas flows over slender bodies with blunted noses on the basis of the hypersonic small perturbation theory the laws of similitude for hypersonic inviscid flow fields over thin or slender bodies are examined and the restrictions to ideal gases with constant specific heats and to bodies with pointed noses are removed only steady plane or axisymmetric flows are considered inspection of the governing system of equations shows that a similitude law exists for flow fields under local thermal equilibrium having the same free stream atmosphere for flows of ideal gas with constant specific heats the requirement of the same free stream atmosphere  i e the same composition pressure and density  can be replaced by the requirement of the same ratio of specific heats for flows over blunted wedges or cones special laws of similitude can be obtained application of the similarity rules is examined for the case of hypersonic flows of an ideal gas with over flat plates with blunt leading edges and for the case of equilibrium air flows over wedges the possibility of simulating nonequilibrium flows over slender or thin bodies is also pointed out
CRAN	boundary layer interaction on a yawed infinite wing in hypersonic flow boundary layer interaction on a yawed infinite wing in hypersonic flow the equations are given for the laminar boundary layer equations on a yawed infinite wing for constant wall temperature under the combined howorth and mangler transformation diagrams show the relatively small influence of yaw the increase of boundary layer secondary flow and the variation of the local heat transfer rate with yaw
CRAN	influence of the leading edge shock wave on the laminar boundary layer at hypersonic speeds influence of the leading edge shock wave on the laminar boundary layer at hypersonic speeds in order to bring out the importance of the leading edge region at hypersonic speeds the influence of the leading edge shock wave on the laminar boundary layer is investigated in two simple cases of steady flow over a semi infinite insulated flat plate 1 sharp leading edge 2 blunt leading edge as approximated by a normal shock wave the streamlines that enter the boundary layer over a large region of the plate surface has previously crossed the shock wave very near the leading edge where the shock is strong and highly curved consequently the temperature at the outer edge of the boundary layer is appreciably higher than free stream temperature and the vorticity there is not zero the effects of this shock wave larger than the usual errors made in the boundary layer theory and an estimate of these effects can therefore be obtained within the framework of that theory the numerical magnitude of the shock wave influence is found to be appreciable for the case of the blunt leading edge the slope of the curve of induced pressures plotted against the hypersonic interaction parameter closely approaches the experimental data of hammitt and bogdonoff obtained in helium at large values of this parameter these approximate results show that the influence of the leading edge region at hypersonic speeds requires careful theoretical and experimental study
CRAN	the interaction between boundary layer and shock waves in transonic flow the interaction between boundary layer and shock waves in transonic flow experiments of transonic flow past a circular arc profile show that the shock wave pattern and the pressure distribution are strongly dependent upon the state of the boundary layer a change from laminar to turbulent boundary layer at a given mach number changes the flow pattern considerably shock waves can interact with the boundary layer in a manner similar to a reflection from a free jet boundary these shock waves are not distinctly discernible from pressure distribution measurements
CRAN	simplified laminar boundary layer calculations for bodies of revolution and for yawed wings simplified laminar boundary layer calculations for bodies of revolution and for yawed wings since the introduction of momentum methods in boundary layer calculations by von karman and pohlhausen many improvements have been proposed an especially simple solution reduces the problem to a quadrature here it is proposed to extend these methods to elementary three dimensional cases and to compressible laminar boundary layer calculations for comparison the corresponding problems for the turbulent boundary layer are also discussed briefly
CRAN	boundary layer transition with gas injection boundary layer transition with gas injection the mass injection process has been proposed as a method of cooling aerodynamic surfaces and since the amount of coolant required to maintain practical wall temperatures is considerably larger for turbulent than for laminar boundary layers knowledge of the effect of the cooling method on the transition process is certainly important exploratory studies reported here were conducted at mach number 3 7 to ascertain the effects of gas injection on the stability of the laminar boundary layer on a conical surface
CRAN	mass transfer cooling at mach number 4 8 mass transfer cooling at mach number 4 8 mass transfer experiments on a 5 mil wire porous cone of 20 total angle have been conducted at using air and helium injection details of the experimental technique are described in references 1 and 2 in the laminar boundary layer the recovery factors and heat transfer coefficients measured with zero injection agreed within per cent with theory transition reynolds numbers observed on the porous cone with zero injection were half as large as observed on a smooth impermeable model of identical geometry in the same channel but injection of large amounts of air or helium did not cause transition to move forward from its zero injection position on the porous cone distributed roughness of this type apparently does not disturb impermeable wall theory but it masks whatever effective roughness may be caused by discrete pore injection
CRAN	experimental evaluation of heat transfer with transpiration cooling in a turbulent boundary layer at m 3 2 experimental evaluation of heat transfer with transpiration cooling in a turbulent boundary layer at m 3 2 it is found that for prescribed velocity field electrical field and conductivity the current can be calculated by integration work is related to analytic investigation of the boundary layer in a physically reasonable accelerator
CRAN	analysis of effects of diffusion of a foreign gas into the laminar boundary layer of a supersonic flow of air in a tube analysis of effects of diffusion of a foreign gas into the laminar boundary layer of a supersonic flow of air in a tube adiabatic wall temperatures and recovery factors are calculated for pipe flows with an entrance mach number of 5 and with uniform injection of helium predicted values of the recovery factor increase slowly with increasing injection rate and with increasing distance from the tube entrance
CRAN	the analytical design of an axially symmetric laval nozzle for a parallel and uniform jet the analytical design of an axially symmetric laval nozzle for a parallel and uniform jet the equations for the nozzles contours are derived by integration of the characteristic equations of the axially symmetric flow since it is not possible to integrate these equations mathematically in an exact form it was necessary to find a way to approximate the calculations the approximation offers itself by considering and comparing the conditions of the flow in a cone with those in a nozzle as a linearization of the characteristic equations the first part of the report deals with equations for the transition curve by which the conical source flow is converted into a parallel stream of uniform velocity the equations are derived by integration along a mach line of the flow in the region where the conversion takes place a factor f is introduced expressing a relation between the direction and the velocity of the flow along a certain mach line f remains undetermined and is not involved in the final equations in the second part of the report the spherical sonic flow section is converted into a plane circular section of the throat the nozzles contour adjacent to the throat is formed by the arc of a circle connected with the transition curve by a straight line the gas dynamic properties of the boundary mach line are calculated in table 1 the use of which shortens the calculations considerably
CRAN	effect of diffusion fields on the laminar boundary layer effect of diffusion fields on the laminar boundary layer a theory is developed which describes the effect of a general diffusion field on the dynamic and thermal characteristics of a laminar boundary layer on a flat plate in steady compressible flow fluid properties are considered as functions of temperature and local concentration of the foreign gas the diffusion field is described by a differential equation that relates convective and diffusion transfer and which considers diffusion currents arising from gradients of concentration and temperature by means of the usual transformations the system is reduced to a set of ordinary differential equations which in turn are transformed into a set of integral equations the latter is amenable to solution by the method of successive approximations the theory and results have bearing on the problem of control and reduction of aerodynamic heating at hypersonic speeds the special feature of this approach lies in the utilization of diffusion fields for the purpose of reducing the detrimental effects of viscous dissipation although the theory is adapted to a fuller investigation of this problem the numerical examples considered involve mainly diffusion fields of helium with which good results have been achieved at mach numbers 8 and 12 whereas at the higher mach number the influx of heat was practically eliminated a reversal in the direction of heat flow has been effected at the lower mach number
CRAN	transpiration cooling experiments in a turbulent boundary layer at m 3 transpiration cooling experiments in a turbulent boundary layer at m 3 turbulent recovery factor and heat transfer measurements have been made on a porous flat wall section at a nominal mach number of 3 0 and a reynolds number of approximately 4 x 10 using both air and helium as the transpired gas measured heat transfer coefficients correlate well with the compressible theory of rubesin for air and qualitatively with simple film theory for either coolant indicating that the heat transfer from a turbulent boundary layer can be reduced by transpiration cooling to well below that of the uncooled boundary layer at the same reynolds number
CRAN	some experimental techniques in mass transfer cooling some experimental techniques in mass transfer cooling author introduces his survey by a brief review of the history of investigations dealing with boundary layers on impermeable solid surfaces and notes that no true theory exists for turbulent boundary layers the success of studies in this area having been due to the introduction of artificial if ingenious assumptions which permitted empirical correlations fd data the terminology introduced by the author for distinguishing the different situations involving mass transfer from the wall to the stream may give rise to some objections for instance film cooling need not refer only to the injection of a liquid since applications involving gas film cooling exist also his restriction of the term transpiration cooling to refer to the injection through a porous surface of a gas only of the same composition as the exterior stream does not enjoy universal usage the influence of mass transfer on heat transfer through laminar boundary layers and on the transition from laminar to turbulent flow is described with consideration given to the question of the net effect of the stabilizing influence of surface cooling and the destabilizing influence of injection reviewer suggests that authors inaccurate statement to the effect that thus far the higher energy conditions do not threaten to involve turbulent injection so turbulent boundary layer research enjoys a fairly academic serenity broken only by its own frustrations be excused on grounds of poetic license although it ignores the efforts being devoted to the pressing practical problems of erosive burning of solid propellants possibly the most common example of a complete aerothermochemical problem involving distributed surface heat and mass transfer with chemical reaction in a flow system and of effusion cooling of rocket nozzles both of which involve turbulent boundary layer conditions author emphasizes the tedious experimental problems involved in research on boundary layers with blowing and notes the desirability of velocity distribution measurements especially in turbulent injection layers the observation that no good data on concentration profiles in the case of the diffusion boundary layer have been published may be an overstatement since authors bibliography overlooks the work of j berger contribution a letude de linjection parietale doctors thesis university of paris memorial des poudres 38 annex p 1 paris imprimerie nationale 1956
CRAN	the interaction of shock waves with boundary layer on a flat surface the interaction of shock waves with boundary layer on a flat surface the development of supersonic compressors supersonic diffusers and high speed aircraft points to the increasing importance of the interaction between shock waves and boundary layers the experimental work reported here is intended to 1 provide a better understanding of the nature of the shock boundary layer interaction 2 serve as a guide and stimulus to theoretical work and 3 develop an empirical method for predicting the effects of the interaction experiments were performed on the reflection of an oblique shock from a boundary layer on a flat surface at a mach number of 2 05 the effects of shock strength and boundary layer regime were explored the results are in the form of schlieren photographs constant density contours found from interferometer photographs and static pressure distributions at the plate surface
CRAN	measurements of turbulent friction on a smooth flat plate in supersonic measurements of turbulent friction on a smooth flat plate in supersonic direct measurements of supersonic local skin friction using the floating element technique are presented for mach numbers from bulent flow and transition are emphasized although some measurements in the laminar regime are included the observed effect of compressibility is to reduce the magnitude of turbulent skin friction by a factor of two at a mach number of 4 5 and a reynolds number of about 10 the boundary layer momentum integral equation for constant pressure is verified within a few per cent by two experimental methods typical static pressure measurements are presented to show that transition can be detected by observing disturbances in pressure associated with changes in displacement thickness of the boundary layer it is found that the turbulent boundary layer cannot be defined experimentally for values of less than about 2 000 where is the momentum thickness for larger values of there is a unique relationship between local friction coefficient and momentum thickness reynolds number at a fixed mach number the appendix compares the present measurements at m 2 5 with experimental data from other sources
CRAN	boundary layer measurements in hypersonic flow boundary layer measurements in hypersonic flow experimental data are presented on boundary layer formation heat transfer and skin friction coefficient at mach numbers of the wall of a conical nozzle in the presence of a favorable pressure gradient and several rates of heat transfer the reynolds number based on momentum thickness varied from 1 500 to 3 500 comparison is made with data at lower mach numbers and with the semiempirical theory of von karman the existing data up to mach numbers of nine indicate agreement to within 5 per cent when compared with a form of the wilson theory but it is clear that the effects of heat transfer and pressure gradients present problems which require extensive study and experiment in the future
CRAN	turbulent boundary layer in compressible fluids turbulent boundary layer in compressible fluids the continuity momentum and energy differential equations for turbulent flow of a compressible fluid are derived and the apparent turbulent stresses and dissipation function are identified a general formula for skin friction including heat transfer to a flat plate is developed for a thin turbulent boundary layer in compressible fluids with zero pressure gradient curves are presented giving skin friction coefficients and heat transfer coefficients for air for various wall to free stream temperature ratios and free stream mach numbers in the special case when the boundary layer is insulated this general formula yields skin friction coefficients higher than those given by the von karman wall property compressible fluid formula but lower than those given by the von karman incompressible fluid formula heat transfer from the boundary layer to the plate generally increases the friction and heat transfer coefficients
CRAN	numerical solution of the boundary layer equations without similarity assumptions numerical solution of the boundary layer equations without similarity assumptions the crocco transformation combined with a mangler transformation is used to carry the boundary layer problem for axially symmetric blunt bodies into a form suitable for direct numerical computation without introduction of similarity assumptions conditions which in the original problem appear at infinity now are brought to a finite straight line and the body is transformed to a parallel line data can be generated on the stagnation line the equations are a parabolic system of two second order equations the boundary value problem is analogous to the slab problem for the heat equation an implicit difference equation is used to reduce stability difficulties special techniques in forming the difference equation result in a linear system of algebraic equations to be solved on any given line of integration and these solutions are computed from recursion relations generated by back substitution for bluntnosed bodies with approach flow mach numbers greater than 8 approximately large temperature gradients occur across a thin boundary layer of dissociated gas and it is necessary to use real gas effects approximated here by certain fits to the gas tables a case is computed however for a lower mach number approach flow using perfect gas theory to provide a standard against which similarity solutions may be tested
CRAN	laminar jet mixing of two compressible fluids with heat release laminar jet mixing of two compressible fluids with heat release the laminar jet mixing problems with heat release have been formulated a general discussion of the solution of these problems is also given the important parameters of these problems are brought out some specific cases of the jet mixing problem such as jet mixing of one compressible fluid isothermal jet mixing of two compressible fluids and isovel jet mixing of two compressible fluids with heat release are discussed in detail
CRAN	thermal distributions in jeffrey hamel flows between nonparallel plane walls thermal distributions in jeffrey hamel flows between nonparallel plane walls the authors give the exact solution for the thermal distributions for the steady laminar flow of a viscous incompressible fluid between non parallel plane walls held at a constant temperature the velocity profiles are determined with the aid of jacobian elliptic functions by using the jeffery hamel solution of the hydrodynamic problem it is shown that in this special case the energy equation giving the temperature profiles can be reduced to an ordinary linear differential equation with variable coefficients after the introduction of dimensionless parameters numerical solutions are given for diverging and converging channels with total openings of 10degree for the possible combinations of three reynolds numbers and five prandtl numbers
CRAN	on heat transfer over a sweat cooled surface in laminar compressible flow with a pressure gradient on heat transfer over a sweat cooled surface in laminar compressible flow with a pressure gradient a simple expression is derived for the normal injection velocity distribution theoretically required to maintain a given uniform temperature along a porous surface in the laminar boundary layer region of a compressible flow with a given velocity distribution outside of the boundary layer this expression is valid for any given free stream mach number but is based on a prandtl number of unity and on the assumption that the viscosity coefficient varies linearly with the temperature by using the dorodnitsyn type of transformation the variation of fluid properties even in the case of zero mach number is taken into account this study is of particular practical interest in connection with the sweat cooling of turbine blades and of airfoil surfaces in high speed flow the method of analysis consists of applying the karman pohlhausen method to both the momentum and energy boundary layer equations and of using an additional heat balance equation involving the coolant temperature a closed form approximate solution of the equations is then derived numerical examples for flow in the immediate vicinity of a stagnation point and for a typical type of flow over a turbine blade are given
CRAN	the effect of helium injection at an axially symmetric stagnation point the effect of helium injection at an axially symmetric stagnation point an effective means of protecting the surface of a hypersonic re entry vehicle is to inject small quantities of a lightweight gas into the boundary layer through a porous wall this process which is known as mass transfer cooling protects the surface in two ways first of all as the injected gas or coolant passes from the reservoir through the wall to the surface a considerable quantity of heat is absorbed as its temperature is raised from the reservoir temperature to the wall surface temperature characteristically lightweight gases have relatively high specific heats secondly the transfer of mass and enthalpy by convection and diffusion normal to the surface alters the characteristics of the boundary layer in such a manner as to reduce the temperature gradient at the wall and hence the conductive heat transfer at the wall this is sometimes referred to as the blowing effect
CRAN	laminar heat transfer and pressure measurements over blunt nosed cones at large angle of attack laminar heat transfer and pressure measurements over blunt nosed cones at large angle of attack tests have been conducted at a mach number of 6 in the pibal hypersonic facility in order to determine the heat transfer and pressure distributions over a slender blunted cone at angles of attack of erature ratio stagnation to wall was approximately 2 3 the model tested has a sperical nose diameter of 1 0 in a base diameter of 3 75 in and a cone half angle of 20 degrees the measurements were made at 5 peripheral stations on the model in this note the experimental results at a 15 degree angle of attack are presented a more detailed analysis of the results for all angles of attack is presented in reference 1
CRAN	the injection of air into the dissociated hypersonic laminar boundary layer the injection of air into the dissociated hypersonic laminar boundary layer in first approximation dissociated air may be treated as a binary mixture of air atoms and air molecules in order to include the effects of mass transfer into the boundary layer it becomes necessary to introduce a third chemical species and hence a second diffusion equation we have avoided this complexity by considering the injection of air molecules into the boundary layer and hence the theoretical treatment is accomplished within the framework of a binary mixture gas
CRAN	on optimum nose curves for missiles in the super aerodynamic regime on optimum nose curves for missiles in the super aerodynamic regime author shows that the differential equations defining the minimum drag body shapes for free molecule flow that were developed and numerically integrated by w j carter amr 11 1958 rev realized however that numerical or analytical integration of the second order differential equation is unnecessary since for the flow conditions considered the first integral to the euler equation can be written prior to the substitution of the expression defining the pressure coefficient
CRAN	optimum nose shapes for missiles in the super aerodynamic region optimum nose shapes for missiles in the super aerodynamic region the mechanics of the kinetic theory of gases is employed to describe the drag force on the nose of a missile moving in the super aerodynamic region of the atmosphere three separate cases are considered  ideal specular reflection specular type reflection from a slightly rough surface and surface absorption followed by random emission of the striking molecules the calculus of variations is employed to obtain the differential equation of the nose shape which minimizes the drag force for each of the three cases the resulting differential equations are then solved by a numerical procedure the drag coefficients for the optimum nose shapes are likewise determined and these are compared with the drag coefficients given by other nose shapes it is further shown that the drag coefficients arising when specular type reflections occur are significantly dependent on the nose shape when surface absorption followed by random emission occurs the drag coefficient is not strongly dependent on either the missile nose shape or the fineness ratio of the nose
CRAN	on the model of the free shock separation turbulent boundary layer on the model of the free shock separation turbulent boundary layer by free shock separated boundary layers one means that type of separation where the flow downstream of the separation region is free to adjust to any direction that may result from the shock boundary layer interaction process a detailed model of the free shock separated turbulent boundary layer is postulated and the pressure rise following from this model is estimated and compared with experiments the results are applied to the prediction of separation in an overexpanded nozzle
CRAN	note on the hypersonic similarity law for an unyawed cone note on the hypersonic similarity law for an unyawed cone it is now known that the hypersonic similarity law derived for slender cones and ogival bodies under the assumption is applicable for mach numbers as low as 3 this note makes use of a series development to infer the hypersonic similarity law for unyawed cones from the taylor maccoll differential equations and associated boundary conditions a simple approximate formula for the function of the similarity law is obtained and the drag function computed with this formula is compared with kopals numerical results and for very slender cones with von karmans linearized formula
CRAN	lift on inclined bodies of revolution in hypersonic flow lift on inclined bodies of revolution in hypersonic flow the importance of body lift lies in the fact that at moderate angles of attack and high mach number it can constitute an appreciable part of the total lift of a winged missile in this paper an attempt has been made to analyze body lift in hypersonic flow by an approximate method and together with a correlation of existing experimental data to indicate the probable variation of body lift over a wide range of mach numbers extending from low supersonic to hypersonic the method of analysis of hypersonic flow over inclined bodies of revolution employed herein has been denoted as the hypersonic approximation it is an improvement on the newtonian corpuscular theory of aerodynamics since it considers the centrifugal forces resulting from the curved paths of the air particles in addition to the impact newtonian forces
CRAN	the flow of a viscous liquid past a flat plate at small reynolds number the flow of a viscous liquid past a flat plate at small reynolds number the authors repeat the earlier calculations of piercy and winny proc roy soc london ser a 140 1933 earlier works were known to be different from each other the careful analysis of the present authors shows that the skin friction coefficient up to the second approximation agrees perfectly with that of piercy and winny
CRAN	three dimensional effect of flutter in a real fluid three dimensional effect of flutter in a real fluid in ref 1 an alternative semi empirical formulation for flutter in a real fluid is given for more accurate determination of the empirical coefficients the three dimensional effect of finite span should be taken into account following reissners approximation for large aspect ratio rectangular wings the boundary value problem governing the downwash w and the vorticity distribution
CRAN	an alternative formulation of the problem of flutter in real fluids an alternative formulation of the problem of flutter in real fluids it is well known in steady flow that the actual lift curve slope is somewhat less than that predicted by inviscid flow theory even at small angles of attack as the stall angle is approached the lift curve slope continually decreases and thus deviates even more from the theoretical value pinkerton employed the measured circulation to determine the pressure distribution and found that the resulting prediction of the moment is considerably improved over that given by the classical theory this amounts to replacing the conventional kutta joukowski condition with the condition that the total lift should agree with the measured value and this in turn completely determines the flow pattern practically this is accomplished by giving a fictitious camber to the profile since potential flow theory is valid outside of the boundary layer once the boundary layer thickness is known the potential flow may be corrected for the displacement thickness and the viscous wake by appropriate source distributions the boundary layer cannot be evaluated of course until the potential flow is known and the circulation is applied a criterion to determine the circulation by generalizing the kutta joukowski condition was proposed by preston and spence by assuming that the pressure at the trailing edge shall have the same value when determined from the potential flow values above and below the airfoil this procedure gives qualitative information concerning viscous effects in steady flow
CRAN	a method for analysing the insulating properties of the laminar compressible boundary layer a method for analysing the insulating properties of the laminar compressible boundary layer in some cooling problems associated with high energy flows it may be convenient to localize strongly the cooling as for example by injecting a coolant through an upstream porous strip and to depend on the insulating properties of the boundary layer to reduce or to eliminate completely the need for further cooling on the surface downstream of the highly cooled section this upstream cooling technique may be of interest in connection with optical windows in hypersonic wind tunnels and on radomes wings and bodies of high speed aircraft and missiles in this paper a method for investigating the insulating properties of a laminar compressible boundary layer on a two  dimensional surface with zero heat transfer is presented the physical situation considered thus corresponds to the case in which the heat transfer downstream of the strongly cooled section is completely eliminated of practical concern is how the temperature of the uncooled surface varies in the downstream direction from its low initial value and thus how the low energy layer established by the upstream cooling insulates the downstream surface the karman integral method extended to both the momentum and energy partial differential equations of the boundary layer has been used the station at which cooling and or injection ceases corresponds to a discontinuity in boundary conditions and thus in solutions at this point the flux of mass momentum and energy within the boundary layer has been made continuous by the introduction of three additional parameters in the velocity and stagnation enthalpy profiles thus the velocity and stagnation enthalpy profiles have both been taken as sixth degree polynomials the resulting two integral differential equations are then solved for two unknown functions of the distance along the wall these two functions are related to the boundary layer thickness and to the wall temperature initial conditions corresponding to a given initial wall temperature and an initial boundary layer thickness are prescribed exact closed form solutions for the case of zero axial pressure gradient are obtained for flows with significant pressure gradients numerical solutions are required in general several numerical examples of practical interest are presented
CRAN	the homogeneous boundary layer at an axisymmetric stagnation point with large rates of injection the homogeneous boundary layer at an axisymmetric stagnation point with large rates of injection this report presents a theoretical analysis of the boundary layer at an axisymmetric stagnation point with large rates of air injection the results of a previous investigation indicated that for localized mass transfer in the stagnation region the rates of injection are considerably greater than those usually treated the exact stagnation point boundary layer equations are integrated numerically for an approximate representation of the gas properties the two point boundary conditions are treated in a new manner which is useful for various boundary layer and mixing problems the exact solutions indicate that for large rates of injection the boundary layer is closely represented by an inner isothermal shear flow and by and exterior relatively thin region in which the flow variables change to their free stream values an integral method based on profiles suggested by the exact solutions is developed and shown to lead to accurate predictions of the integral thicknesses which are of interest for a study of the downstream influence of the stagnation point mass transfer
CRAN	helium injection into the boundary layer at an axisymmetric stagnation point helium injection into the boundary layer at an axisymmetric stagnation point this report presents a theoretical analysis of the boundary layer at an axisymmetric stagnation point with large rates of helium injection the exact stagnation point boundary layer equations are integrated numerically with approximate representations of the gas properties the treatment of the two point boundary value problem employed herein is shown to be useful for various boundary layer and mixing problems the exact solutions indicate that for large rates of injection the boundary layer can be represented by a thick inner layer of constant shear temperature and composition and by a relatively thin outer region in which the flow variables adjust to their free stream values an inviscid flow model is shown to lead to accurate predictions of this shear layer and will thus provide sufficiently accurate profiles for use in the study of the downstream influence of stagnation point mass transfer the heat transfer to the stagnation point is also considered tabulations of the eigenvalues for a variety of wall conditions and injection rates are given
CRAN	control system and analysis and design via the second method of lyapunov control system and analysis and design via the second method of lyapunov the second method of lyapunov is the most general approach currently in the theory of stability of dynamic systems after a rigorous exposition of the fundamental concepts of this theory applications are made to a stability of linear stationary linear nonslationary and nonlinear systems b estimation of transient behavior c control system optimization d design of relay servos the discussion is essentially self contained with emphasis on the thorough development of the principal ideas and mathematical tools only systems governed by differential equations are treated here systems governed by difference equations are the subject of a companion paper
CRAN	some problems of polar missile control some problems of polar missile control a polar controlled missile is one in which manoeuvre is carried out by rotations about roll and pitch axes that is in the manner of a conventional aeroplane this paper discusses some problems in the application of this form of control to homing missiles in comparison with the alternative cartesian configuration this method presents some special design problems in the former case it is often possible to resolve the motion into two planes and consider the pitch and yaw control systems as independent two dimensional problems this simplification is not possible in the case of polar control and it is usually necessary to consider the whole three dimensional system the equations of motion which result are in general not susceptible to analysis because of this the design of control systems requires extensive use of simulators
CRAN	an approximate solution of the supersonic blunt body problem for prescribed arbitrary axisymmetric shapes an approximate solution of the supersonic blunt body problem for prescribed arbitrary axisymmetric shapes the integral method of belotserkovskii has been carried out to the first approximation for arbitrary blunt axisymmetric bodies in supersonic or hypersonic flight this method is direct in that it gives the surface pressure distribution and shock shape for a prescribed body results obtained by numerical integration for several body shapes at several mach numbers are compared to experimental results with good agreement it is also shown that the method can be successfully applied to pointed bodies with attached shock in the stagnation region simple relationships are found from the equations of the first approximation which connect the surface velocity gradient shock curvature shock detachment distance and body curvature these relations are also correlated with experiment for a variety of shapes as a function of mach number the correlations permit a rapid estimate of the stagnation point velocity gradient important for heat transfer calculations for any blunt body from the shock stand off distance a method for a higher approximation is described for which in contrast to the higher approximations of belotserkovskii a large number of simultaneous total differential equations with unknown parameters does not occur one form of this method has been studied numerically results are given which though only partially successful indicate the amount of improvement to be expected from a higher approximation
CRAN	theoretical pressure distribution on a hemisphere cylinder combination theoretical pressure distribution on a hemisphere cylinder combination in recent years great use has been made of approximate methods for the determination of the pressure distribution on blunt nosed bodies and afterbodies at high mach numbers for quasi spherical bodies it has been suggested that modified newtonian theory in combination with a prandtl meyer expansion be used on the nose portion the two laws being matched at the point where the pressure gradients are equal no simple approximation however has been found for flat nosed bodies as for the pressure distribution on the afterbody the blast wave analogy has been suggested for general nose shapes but particular afterbody profiles the purpose of the present note is to compare these approximate estimates with a more accurate determination of the flow field about a hemisphere cylinder in an ideal gas flow it was felt that since experimental investigations in air at this mach number are scarce and very difficult to obtain the comparison would be of interest the basis of comparison is the flow field as it results from a numerical integration of the exact equations governing the motion of the ideal fluid
CRAN	note on tip bluntness effects in the supersonic and hypersonic regimes note on tip bluntness effects in the supersonic and hypersonic regimes in a recent letter m h bertram presents some data on flows at m 6 85 around 10 half angle cones with blunted tips since the demarcation between the supersonic and hypersonic regimes is not sharp and since one expects hypersonic flows to be generally similar to those at lower mach numbers   especially where viscous effects do not predominate throughout the entire field of interest  it is of some value to compare bertrams results with those obtained by giese and bergdolt for 15 half angle cones at m 2 45 following the observation by charters and stein that drag coefficient measurements on blunted cones imply a reynolds number effect giese and bergdolt study the convergence to conical flow of the perturbed flow about a cone with truncated tip they employ the mach zehnder interferometer and the conical flow criterion as analytical tools
CRAN	an experimental investigation of flow about simple blunt bodies at a nominal mach number of 5 8 an experimental investigation of flow about simple blunt bodies at a nominal mach number of 5 8 an experimental investigation was conducted in the galcit hypersonic wind tunnel to determine flow characteristics for a series of blunt bodies at a nominal mach number of 5 8 and free stream reynolds numbers per in of measured values for the pressure coefficient distributions are compared with a modified newtonian expression the agreement is very good for the three dimensional bodies and is fair for the circular cylinder transverse to the free stream flow direction a complete report of the investigation is given in a galcit hypersonic wind tunnel memorandum
CRAN	the generalized expansion method and its application to bodies travelling at high supersonic airspeeds the generalized expansion method and its application to bodies travelling at high supersonic airspeeds it is demonstrated that the shock expansion method can be generalized to treat a large class of hypersonic flows only one of which is flow about airfoils this generalized method predicts the whole flow field including shock wave curvatures and resulting vorticity providing that 1 disturbances originating on the surface of an object are largely absorbed in shock waves with which they interact and 2 disturbances associated with the divergence of stream lines in tangent planes to the surface are of secondary importance compared to those associated with the curvature of stream lines in planes normal to the surface it is shown that these conditions may be met in three dimensional as well as two dimensional hypersonic flows when they are met surface streamlines may be taken as geodesics which in turn may be related to the geometry of the surface the validity of the generalized shock expansion method for three dimensional hypersonic flows is checked by comparing predictions of theory with experiment for the surface pressures and bow shock waves of bodies of revolution the bodies treated are two ogives having fineness ratios of 3 and 5 tests were conducted at mach numbers from 2 7 to 6 3 and angles of attack up to 15 degrees in the 10  by 14 in supersonic wind tunnel of the ames aeronautical laboratory at the lower angles of attack theory and experiment approach agreement when the ratio of mach number to fineness ratio  that is the hypersonic similarity parameter  exceeds 1 at the larger angles of attack theory tends to break down as would be expected on the leeward sides of the bodies as a final point it is inquired if the two dimensionality of inviscid hypersonic flows has any counterpart in hypersonic boundary layer flows the question is answered in the affirmative and results of experiment are employed to provide a partial check of this conclusion
CRAN	an investigation of optimum zoom climb techniques an investigation of optimum zoom climb techniques the problem of optimal zoom climb maneuvering of a turbojet aircraft has been investigated using the mayer formulation of the calculus of variations the euler lagrange equations governing optimum symmetric flight have been integrated numerically by digital computation discontinuities in thrust arising from turbojet afterburner blowout have been treated and conditions which must be satisfied across the interface generated by the discontinuity have been derived arbitrary control techniques have been compared with the optimum and it has been found that performance is relatively insensitive to piloting technique unless a time limitation is imposed which requires high maneuvering load factors
CRAN	steady flow in the laminar boundary layer of a gas steady flow in the laminar boundary layer of a gas if the boundary layer equations for a gas are transformed by misess transformation as was done by karman tsion for the flow along a flat plate of a gas with unit prandtl number the computation of solutions is simplified and use may be made of previously computed solutions for an incompressible fluid for any value of the prandtl number and any variation of the viscosity with the temperature t after the method has been applied to flow along a flat plate a problem otherwise treated by crocco the flow near the forward stagnation point of a cylinder is calculated with dissipation neglected both with the effect of gravity on the flow neglected and with this effect retained for vertical flow past a horizontal cylinder the approximations involved by the neglect of gravity are considered generally and the cross drift is calculated when a horizontal stream flows past a vertical surface when and the boundary is heat insulated it is shown that the boundary layer equations for a gas may be made identical whatever be the main stream with the boundary layer equations for an incompressible fluid with a certain determinable main stream the method is also applied to free convection at a flat plate variation with altitude of the state of the surrounding fluid neglected and to laminar flow in plane wakes but for plane jets the conditions previously imposed by howarth are also imposed here in order to obtain simple solutions
CRAN	transformation between compressible and incompressible boundary layer equations transformation between compressible and incompressible boundary layer equations it is proposed to show that the boundary layer equation of compressible flow can be reduced to that of incompressible flow such work was initiated by stewartson and by rott and crabtree in the following some of the restrictions imposed by references 1 and 2 will be removed and it will be shown that the transformation from compressible boundary layer to incompressible boundary layer can be applied to the laminar as well as turbulent case a direct method will be used for this purpose
CRAN	a turbulent analog of the stewartson illingworth transformation a turbulent analog of the stewartson illingworth transformation the stewartson illingworth transformation is applied to the integral momentum equation for compressible boundary layer flow leaving the x coordinate transformation unspecified however it is shown that the transformed equation is the integral momentum equation for incompressible flow if a the effect of compressibility on the boundary layer shape parameter h can be represented by and b the x coordinate transformation is chosen to be suitably related to the ratio of skin friction coefficients in compressible and incompressible flows experimental evidence is presented which shows that condition a is satisfied for turbulent boundary layers up to m 5 an x transformation is chosen according to b and an equation is presented which gives the turbulent boundary layer growth in compressible flow in terms of a simple quadrature the predictions of this equation are then compared with some measurements on wind tunnel nozzles
CRAN	engineering relations for friction and heat transfer to surfaces in high velocity flow engineering relations for friction and heat transfer to surfaces in high velocity flow in calculations of thermodynamic heating for high speed missiles parameters have been used based on relationships which hold for constant property fluids the validity of this procedure has been verified recently in a survey of heat transfer in which a relationship for the reference temperature was developed a calculation procedure for laminar and turbulent boundary layers based on this relationship is given
CRAN	reverse flow and variational theorems for lifting surfaces in nonstationary compressible flow reverse flow and variational theorems for lifting surfaces in nonstationary compressible flow a reverse flow theorem for compressible nonsteady flow valid within the limits of linearized theory is derived this theorem gives a general class of relations between linearized solutions for lifting surfaces in direct and reverse flow based on the same considerations used to establish the theorem an adjoint variational principle which may be useful in approximate solutions of non steady lifting surface problems is obtained to illustrate the uses of the reverse flow theorem it is applied to the determination of relations between aerodynamic coefficients in direct and reverse flow and to the obtaining of influence functions for total lift pitching moment and rolling moment for a wing oscillating with arbitrary motion and surface deformation in terms of the pressure distributions for simpler cases in reverse flow
CRAN	effect of quasi steady air forces on incompressible bending torsion flutter effect of quasi steady air forces on incompressible bending torsion flutter explicit solutions are obtained for the bending torsion flutter of a two dimensional airfoil in incompressible flow under the assumptions that the theodorsen function c k is set equal to a real constant and the diagonal virtual mass terms are negligible for the case of small bending to torsion frequency ratio a comparison is made of these quasi steady solutions with an earlier empirical expression suggested by theodorsen and garrick for the nonsteady case and the effect of the c k function is indicated the importance of the c g location for these small cases is re emphasized and the possibility of flutter at zero air speed is indicated
CRAN	the axisymmetric boundary layer on a long thin cylinder the axisymmetric boundary layer on a long thin cylinder the laminar boundary layer in axial flow about a long thin cylinder is investigated by two methods one 2 is a pohlhausen method based on a velocity profile chosen to represent conditions near the surface as accurately as possible the other 3 is an asymptotic series solution valid far enough downstream from the nose for the boundary layer thickness to have become large compared with the cylinder radius another series solution due to seban bond and kelly is known valid near enough to the nose for the boundary layer to be thin compared with the cylinder radius the pohlhausen solution shows good agreement with both series near and far from the nose and enables an interpolation to be made 4 between them in the extensive range of distances from the nose for which neither is applicable the final recommended curves for the variation along the cylinder of skin friction boundary layer displacement area and momentum defect area are displayed in graphical and tabular form figure 1 and table 1 and are expected to be correct to within about 2 the velocity near the wall is closely proportional to the logarithm of the distance from the axis this is the profile used in the pohlhausen method the analogy with the distribution of mean velocity in turbulent flow over a flat plate is discussed at the end of 2
CRAN	a note on the laminar boundary layer on a circular cylinder in axial incompressible flow a note on the laminar boundary layer on a circular cylinder in axial incompressible flow a correction is made for the equation to compute the ratio of the displacement thickness on a cylinder to the corresponding thickness on a flat plate
CRAN	integration of the boundary layer equations for a plane in compressible flow with heat transfer integration of the boundary layer equations for a plane in compressible flow with heat transfer the equations of motion of compressible viscous flow with vanishing pressure gradient past a plane are integrated in semi convergent expressions for the case when the physical constants depend on temperature and the prandtl number is close to unity simple expressions are obtained for the temperature and velocity distributions in the boundary layer the drag coefficient and their dependence on the physical constants they contain the well known results and several new ones for the case when the temperature of the boundary is either above or not much below the temperature of the main flow the results obtained closely agree with croccos numerical computations
CRAN	application of second order shock expansion theory to several types of bodies of revolution application of second order shock expansion theory to several types of bodies of revolution second order shock expansion theory is utilized to obtain equations for the initial normal force curve slope initial pitching moment curve slope and zero lift wave drag for several type bodies of revolution bodies considered are the cone cylinder cone cylinder frustum cone cylinder frustum booster cone frustum and cone frustum booster
CRAN	on a generalised porous wall couette type flow on a generalised porous wall couette type flow in a recent paper the problem of a couette type flow in which the fixed wall is porous has been considered the results quoted in the above reference can be obtained rigorously by the method stated below in which a different interpretation to one of the parameters is made
CRAN	a generalised porous wall couette type flow a generalised porous wall couette type flow recently it was observed that the two existing boundary layer texts references 1 and 2 did not contain a solution for the case of couette flow with a constant uniformly distributed suction or blowing thus the following analysis considers a couette type flow between a stationary flat surface and a slightly inclined flat plate moving at a constant velocity in addition the flow is subjected to a constant uniformly distributed suction or blowing at the fixed surface
CRAN	heat transfer for laminar flow in an annulus with porous wall heat transfer for laminar flow in an annulus with porous wall temperature profiles and heat transfer rates of established incompressible flow through an annulus channel with porous walls of constant temperatures are determined at different injection rates axial conduction and viscous dissipation are as usual neglected injecting fluid is tacitly assumed to have the same temperature as the porous wall
CRAN	the pressure gradient induced by shear flow past a flat plate the pressure gradient induced by shear flow past a flat plate article is a continuation of an earlier note on papers by li on a semiinfinite plate in a uniform shear flow li had deduced from the form of his equations that stream vorticity caused an induced pressure gradient in the flow later papers by li and murray amr 15 1962 rev 7157 support the induced pressure gradient theory the author notes however that the mathematics used by li and murray are not acceptable and the problem thus not resolved the present note sets up simple models of complete flows examinable by elementary means author holds that analyses demonstrate conclusively that no pressure gradient is induced in the boundary layer on a flat plate in a limited region of shear flow he notes that the original question in the case of unbounded shear remains obscure  and anyway an unlimited shear layer is not of great practical importance
CRAN	simple shear flow past a flat plate in a compressible viscous fluid simple shear flow past a flat plate in a compressible viscous fluid by transformation of variables the problem of a simple shear flow of a compressible fluid over a flat plate is reduced to the corresponding problem for an incompressible fluid the prandtl number of the compressible fluid is assumed to be unity and its viscosity to be a linear function of temperature
CRAN	some panel flutter studies using piston theory some panel flutter studies using piston theory the use of piston theory was recently advocated for supersonic aeroelastic analyses including the problem of panel flutter and this has stimulated the investigation reported here linear piston theory is mainly considered but some effects of introducing higher order terms are discussed flutter of rectangular simply supported panels and of elliptically shaped clamped edge panels is considered and some justification is provided for the use of static aerodynamic forces and the neglect of aerodynamic damping hence it is concluded that ackeret loading gives more exact results than piston theory solution of the flutter equations is made by applying galerkins method to a rayleigh type analysis using assumed modes of deformation
CRAN	flutter of rectangular simply supported panels at high supersonic speeds flutter of rectangular simply supported panels at high supersonic speeds the problem of panel flutter of rectangular simply supported plates subjected to supersonic flow over one surface is treated theoretically the assumption is made and subsequently verified that the static approximation to the aerodynamic flutter forces yields flutter boundaries with satisfactory accuracy for mach numbers greater than about 2 two panel flutter analyses are performed using this static approximation in conjunction with thin plate theory  one employs aerodynamic strip theory the other aerodynamic surface theory the influence of mach number dynamic pressure panel aspect ratio and midplane stress on the panel thickness required to prevent flutter is determined for extensive ranges of these parameters
CRAN	natural frequencies of rectangular plates with edges elastically restrained against rotation natural frequencies of rectangular plates with edges elastically restrained against rotation plates with attachments to heavier members along the edges can be described as having edges elastically restrained against rotation in many cases uniformly along each edge at the edges setting slope when is the edge bending moment with always positive the elastic restraint can be analytically defined with describing respectively clamped and simply supported edges in this note natural frequencies of such plates are calculated mainly following the nomenclature of dana young
CRAN	the shear flow along a flat plate with uniform suction the shear flow along a flat plate with uniform suction recently several authors have investigated the boundary layer in a shear flow in this note an exact solution of the navier stokes equations will be presented which represents the boundary layer along an infinite flat plate with uniform suction situated in a shear flow
CRAN	the viscous flow near a stagnation point when the external flow has uniform vorticity the viscous flow near a stagnation point when the external flow has uniform vorticity in view of the recent controversy between li and glauert on the nature of the solution of the boundary layer equations when the external flow is rotational it seems worthwhile to draw attention to a certain exact solution of the navier stokes equations which lends support to glauerts point of view
CRAN	new methods in heat flow analysis with application to flight structures new methods in heat flow analysis with application to flight structures new methods are presented for the analysis of transient heat flow in complex structures leading to drastic simplifications in the calculation and the possibility of including nonlinear and surface effects these methods are in part a direct application of some general variational principles developed earlier for linear thermodynamics they are further developed in the particular case of purely thermal problems to include surface and boundary layer heat transfer nonlinear systems with temperature dependent parameters and radiation the concepts of thermal potential dissipation function and generalized thermal force are introduced leading to ordinary differential equations of the lagrangian type for the thermal flow field because of the particular nature of heat flow phenomena compared with dynamics suitable procedures must be developed in order to formulate each problem in the simplest way this is done by treating a number of examples the concepts of penetration depth and transit time are introduced and discussed in connection with one dimensional flow application of the general method to the heating of a slab with temperature dependent heat capacity shows a substantial difference between the heating and cooling processes an example of heat flow analysis of a supersonic wing structure by the present method is also given and requires only extremely simple calculations the results are found to be in good agreement with those obtained by the classical and much more elaborate procedures
CRAN	variational and lagrangian thermodynamics of thermal convection fundamental shortcomings of the heat transfer coefficient variational and lagrangian thermodynamics of thermal convection fundamental shortcomings of the heat transfer coefficient extension of previous analyses indicating the possibility of extending the thermodynamics of irreversible processes to systems which are not in the vicinity of an equilibrium state and for which onsagers relations are not verified this involves generalizations beyond the narrow field of heat transfer and to principles of wider range than those of current nonequilibrium thermodynamics
CRAN	a sublayer for fluid injection into the incompressible turbulent boundary layer a sublayer for fluid injection into the incompressible turbulent boundary layer a sublayer region is introduced in which the intensity of turbulence grows at a prescribed rate the decrease in wall shear stress due to fluid injection into the boundary layer is found under the hypothesis that the effect of injection is restricted to the sublayer region experimental measurements of the velocity profiles with fluid injection substantiate this hypothesis the theoretical decrease in wall shear stress is in good agreement with experiment the solution is particularly simple and for small values of the injection parameter it contains no arbitrary parameters the theory provides a similarity parameter which differs from the one in general use
CRAN	heat transfer in turbulent shear flow heat transfer in turbulent shear flow the problems of heat transfer in turbulent shear flow along a smooth wall are discussed from the point of view of von karmans well known 1939 paper on the analogy between fluid friction and heat transfer methods for extending the analysis to higher prandtl numbers are suggested
CRAN	conduction of heat in composite slabs conduction of heat in composite slabs a method of calculating the total quantity of heat that passes through a unit area from zero time to time t is developed allowance is made for surface resistance by regarding each contact resistance as an additional layer of the appropriate thermal resistance and zero heat capacity
CRAN	buckling stress of clamped rectangular plates in shear buckling stress of clamped rectangular plates in shear by consideration of antisymmetrical as well as symmetrical buckling configurations the theoretical shear buckling stresses of clamped rectangular flat plates are evaluated more correctly than in previous work the results given which represent the average of upper and lower limit solutions obtained by the lagrangian multiplier method are within percent of the true buckling stresses
CRAN	inviscid hypersonic airflows with coupled non equilibrium processes inviscid hypersonic airflows with coupled non equilibrium processes analyses have been made of the effects of coupled chemical rate processes in external inviscid hypersonic airflows at high enthalpy levels exact numerical solutions have been obtained by the inverse method for inviscid airflow over a near spherical nose under flight conditions where substantial nonequilibrium prevails through the nose region typical conditions considered include nose radii of the order of 1 ft at an altitude of 250 000 ft and velocities of 15 000 and 23 000 ft per sec the results illustrate the general importance of the coupling among the reactions considered these included dissociation recombination bimolecular exchange and ionization reactions the exact solutions show the bimolecular no exchange reactions to be important in blunt nose flow for the kinetics of no and n as they are in the case of a plane shock wave an important difference between blunt nose flow and plane shock flow however is the gasdynamic expansion in the curved shock layer of the former this expansion reduces post shock reaction rates as a consequence in the regime studied the oxygen and nitrogen atom concentrations tend to freeze in the nose region at levels below those for infinite rate equilibrium the reduction below the equilibrium dissociation level can be large particularly for nitrogen dissociation at higher velocities in the regime considered the chemical kinetics are dominated by two body collision processes the inviscid nose flow including coupled nonequilibrium phenomena is thus amenable to binary scaling for a given velocity the binary scaling is demonstrated for a range of altitude and scale by correlation of the exact solutions for given velocity and a constant product of ambient density and nose radius this similitude which can also scale viscous nonequilibrium and radiation phenomena in the shock layer provides a useful flexibility for hypersonic testing where it is applicable the afterbody inviscid flow problem is briefly discussed in the light of the results for the nose flow
CRAN	magnetohydrodynamics shocks magnetohydrodynamics shocks a mathematical treatment of the coupled motion of hydrodynamic flow and electromagnetic fields is given two simplifying assumptions are introduced first the conductivity of the medium is infinite and second the motion is described by a plane shock wave various orientations of the plane of the shock and the magnetic field are discussed separately and the extreme relativistic and unrelativistic behavior is examined special consideration is given to the behavior of weak shocks that is of sound waves it is interesting to note that the waves degenerate into common sound waves and into common electromagnetic waves in the extreme cases of very weak and very strong magnetic fields
CRAN	magnetohydrodynamic shock waves magnetohydrodynamic shock waves an interpretation of the de hoffman teller shock wave equations for an infinitely conducting medium is given analogous to the classical interpretation of the ordinary hydrodynamic shock wave equations of rankine and hugoniot two cases of interest are considered as a consequence of this theory it is shown that weak magnetic fields in interstellar clouds will be amplified and if external mechanisms are available to reduce the compressional effects of shock waves the field will reach a value where p is the pressure also some aspects of the internal motions of prominences are considered it is shown that gauss will yield results in accord with the observational material
CRAN	two dimensional transonic flow past airfoils two dimensional transonic flow past airfoils this report concerns the problem of constructing solutions for transonic flows over symmetric airfoils the aspect of the problem emphasized is of necessity not how to form a solution for compressible flow but how to simplify the initial phase of the problem namely the mapping of the incompressible flow in the case of the symmetric joukowski airfoil without circulation the mapping is relatively simple but the coefficients in the power series are difficult to evaluate as a result the problem requires simplification instead of the exact incompressible flow past the airfoil an approximate flow is used which is derived from a combination of source and sink this flow differs only slightly from the exact one when the thickness is small by the same method the flow with circulation is also considered after the incompressible flow functions are approximated in this fashion the numerical calculation of the corresponding compressible flow by the hodograph theory does not present any essential difficulty
CRAN	tables of thermal properties of gases tables of thermal properties of gases tables of thermodynamic and transport properties of air argon carbon dioxide carbon monoxide hydrogen nitrogen oxygen and steam
CRAN	on the behaviour of boundary layers at supersonic speeds on the behaviour of boundary layers at supersonic speeds this paper considers the implications of recent advances in knowledge of the behaviour of boundary layers in supersonic flow only the simplest case is considered dashthat of the two dimensional boundary layer on a flat plate with nominal zero longitudinal pressure and temperature gradients it is shown that the empirical intermediate enthalpy used with success in approximations for skin friction etc of laminar boundary layers is closely the same as the mean enthalpy with respect to velocity furthermore the mean enthalpics of laminar and turbulent boundary layers may be the same a nonrigorous approach is made to the problems of self induced pressure gradients and the indications are that their effects on laminar skin friction etc may become noticeable at mach numbers greater than 5 and they increase as the surface temperature builds up towards zero heat transfer conditions the effects with turbulent boundary layers may not be so severe finally the results are applied to give an idea of the magnitude of the drag and aerodynamic heating problems up to m 10 and one result is that if there is any conflict at the higher mach numbers between surface conditions required for high radiative emissivity and those which may be thought necessary for preserving a laminar boundary layer then it may be better to choose the former
CRAN	stationary convection flow of an electrically conducting liquid between parallel plates in a magnetic field stationary convection flow of an electrically conducting liquid between parallel plates in a magnetic field a study is made of the stationary convection of an electrically conducting liquid in the space between two parallel plates heated to different temperatures in the presence of a magnetic field the distribution of velocity temperature and induced fields are found and the convective heat flow is calculated
CRAN	on convective motion of a conducting fluid between parallel vertical plates in a magnetic field on convective motion of a conducting fluid between parallel vertical plates in a magnetic field stationary convective motion of a conducting fluid between vertical parallel plates in a magnetic field is considered an exact solution of the magnetohydrodynamic equations is obtained for the case of a constant vertical temperature gradient the critical value of grasshofs number is determined for the case when the temperature of both plates is the same
CRAN	on the base pressure resulting from the interaction of a supersonic external stream with a sonic or subsonic jet on the base pressure resulting from the interaction of a supersonic external stream with a sonic or subsonic jet it is shown that the two dimensional base pressure problems relating to base bleed into the wake of blunt trailing edge airfoils or the interaction between an external supersonic or sonic slipstream with a sonic or subsonic jet stream of a jet engine can be calculated by theoretical considerations constant pressure isoenergetic turbulent mixing between the streams and the stagnant fluid in the wake is assumed the theoretical calculations are in good agreement with the experimental results
CRAN	the supersonic flow about a blunt body of revolution for gases at chemical equilibrium the supersonic flow about a blunt body of revolution for gases at chemical equilibrium the supersonic flow about a blunt body of revolution for gases at chemical equilibrium a method to determine the shock wave and its location about a body of revolution moving at supersonic speeds is given the method provides also the means to compute the flow characteristics in the shock layer the fluid in which the motion takes place is assumed to be in chemical equilibrium within the shock layer its thermochemical properties must be known the essential new features of the method are a it solves the direct problem i e the initial data are the conditions upstream and the body shape b the integration of the fundamental equations is done in the physical plane and the difficulties inherent to other less direct mathematical formulations of the problem are avoided a physical interpretation of the method is made which is in accord with the analytical definition of the problem
CRAN	data on shape and location of detached shock waves in cones and sphere data on shape and location of detached shock waves in cones and sphere accurate experimental data are given on the shape and the location of detached shock waves on cones and spheres at mach numbers from 1 17 to 1 81 the data are correlated to obtain equations that describe the shock waves this knowledge of the shock waves should be useful in calculations of the pressure distribution and the pressure drag of the fore part of cones and spheres the experimental data on shock waves are compared with theory
CRAN	critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation an exact solution and a closely concurring approximate energy solution are given for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation it was found that an appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling an interaction formula in general use was shown to be decidedly conservative for the range in which it is supposed to apply
CRAN	turbulent skin friction at high mach numbers and reynolds numbers in air and helium nasa r82 1960 turbulent skin friction at high mach numbers and reynolds numbers in air and helium nasa r82 1960 results are given of local skin friction measurements in turbulent boundary layers over an equivalent air mach number range from 0 2 to 9 9 and an over all reynolds number variation of 2x10 to 100x10 direct force measurements were made by means of a floating element flows were two dimensional over a smooth flat surface with essentially zero pressure gradient and with adiabatic conditions at the wall air and helium were used as working fluids an equivalence parameter for comparing boundary layers in different working fluids is derived and the experimental verification of the parameter is demonstrated experimental results are compared with the results obtained by several methods of calculating skin friction in the turbulent boundary layer
CRAN	the problem of resistance in compressible fluids the problem of resistance in compressible fluids this report is restricted to the resistance of bodies of revolution and of cylindrical bodies of infinite length moving with uniform velocity in a compressible fluid in the case of bodies of revolution it will be assumed that the direction of the movement is parallel to the axis of symmetry it will be assumed that the fluid satisfies the equation of state of perfect gases i e const where p denotes the pressure the density and t the absolute temperature in addition to obeying this equation the fluid is characterized by the statement that the intrinsic energy of the unit mass amounts to where for simplicitys sake the specific heat will be expressed in work rather than heat units the ratio between the specific heat at constant pressure and the specific heat at constant volume will be denoted by it is known that the value of x depends upon the number of degrees of freedom of the molecules if this number is denoted by n for air the value x 1 4 will be used the limiting case x 1 will be referred to as that of a assumed that in the range considered and are independent of the temperature
CRAN	the aerodynamic design of section shapes for swept wings the aerodynamic design of section shapes for swept wings an extension of work of lock and rogers and the result of cooperation by n p l r a e and members of the british aircraft industry to achieve a satisfactory design for an aircraft cruising at low supersonic speeds knowledge of shock wave prediction onset of wave drag and shock induced separation allows the basic design to be generalized for a wide range of parameters unpublished work by bagley on the relation of aerodynamic coefficients and geometry is used the role of upper surface velocity distribution is noted and methods for predicting pressure distributions with shock waves are reviewed for both subsonic and transonic flows
CRAN	methods of boundary layer control for postponing and alleviating buffeting and other effects of shock induced separation methods of boundary layer control for postponing and alleviating buffeting and other effects of shock induced separation the use of boundary layer control to increase the separation free margins of mach number and lift coefficient beyond the cruise point of high speed aircraft may often be preferred to design changes that impair the cruising performance or the landing and take off characteristics the factors that influence the choice of method and details of its application are discussed emphasising particularly the need to maintain effectiveness over most of the chord to cover the wide range of separation positions encountered as the shock moves over the wing with changing flight conditions research at the national physical laboratory that has embraced high velocity blowing vane and air jet vortex generators and in a preliminary way distributed suction is briefly described the relative merits of the various methods are discussed and some results achieved in their application are given for vortex generators the importance is stressed of the vortex paths determined by the interactions of neighbouring vortices and their images thus systems of counter rotating vortices always leave the surface in pairs and lose their effectiveness co rotating systems are therefore preferred for many applications blowing which in wind tunnel tests gives results as good as or better than vortex generators and does not have the disadvantage of a drag penalty at cruise has not yet been assessed in flight air jet vortex generators which would also avoid the drag penalty show promise of producing significant effects with relatively small blowing pressures and quantities
CRAN	on the stability of two dimensional parallel flows on the stability of two dimensional parallel flows this is the last part of the authors theory of the stability of plane laminar motion for parts 1 and 2 cf the same quart 3 117 142 218 234 1945 these rev 7 225 226 the stability character of a viscous fluid is considered in detail the author proceeds first to give a proof of a criterion of stability due to heisenberg if a velocity profile has an number and phase velocity the disturbance with the same wave number is unstable in the real fluid when the reynolds number is sufficiently large this destabilizing effect of viscosity is one of the most interesting phenomena in the general stability theory its physical and mathematical significance is carefully discussed the author then discusses the behavior of the so called neutral curve for the two characteristic types of velocity distribution the boundary layer type profile and the symmetrical profile the asymptotic behavior of the neutral curve is discussed first the main difference between profiles with and without a point of inflection is that the two branches of the neutral curve approach and for profiles with a flex but both converge to for the profile without a flex the most important results are as follows for sufficiently large reynolds number r 2 there always exists a minimum r below which the motion is stable a similar result was obtained by synge from energy considerations synge found a limiting curve below which the motion is necessarily stable the authors discussion of the asymptotic behavior of the curves shows further that there always exists a maximum value of a beyond which the motion is stable for all reynolds numbers hence the qualitative shape of the curve is determined the author proceeds to show that simple approximate expressions for the stability limit can be obtained from his general analysis for a given velocity profile these approximate stability limits for plane poiseuille flow and blasius flow are found to be r 5906 and r 502 the reynolds numbers are based on the width of the channel and the displacement thickness respectively finally the method for computing the complete instability curve is presented and the plane poiseuille case and the blasius problem worked out in detail the stability limit for blasius flow had been given before by tollmien and schlichting the present more exact computations agree well with tollmiens result as far as the minimum critical reynolds number is concerned the value found here is r 420 the neutral curve for poiseuille motion had not been obtained before the minimum critical number here is found to be r 5314 the agreement with the estimate from the simple criterion mentioned above is thus very good a discussion of the physical significance of the viscous effects and of future developments concludes the paper
CRAN	transition form laminar to turbulent shear flow transition form laminar to turbulent shear flow recent experimental studies of transition from laminar to turbulent shear flows are reviewed certain common features are emphasized and related to the stability theories of viscous shear layers the three dimensional character the unsteadiness and the nonlinear and random behavior of the latter stages of the transition process are also examined
CRAN	the design of intermediate vertical stiffeners on web plates subjected to shear the design of intermediate vertical stiffeners on web plates subjected to shear the correct design of intermediate vertical stiffeners on web plates subjected to shear becomes very important when the web plates are designed to operate at loads close to their buckling loads this paper presents details of an extensive series of tests conducted on stiffened web plates subjected to shear from the analysis of the results obtained from these tests new empirical relationships between the flexural rigidity and spacing of the intermediate stiffeners and the buckling stress of the stiffened web plate have been obtained one interesting and important feature of these new relationships is that they define more clearly than hitherto the difference in the behaviour of single and double sided stiffeners
CRAN	an experimental study of the flow field about swept and delta wings with sharp leading edges an experimental study of the flow field about swept and delta wings with sharp leading edges a series of experiments was performed to define the flow field on the upper surface of high aspect ratio swept wings and narrow delta wings at high angles of attack it was found that near the root section of either type of wing the flow is conical the edge of the vortex sheet which originates at the leading edge is a straight line whose position relative to the leading edge depends only on incidence on swept wings the vortex edge turns down stream as soon as the vortex sheet covers the front half of the wing chord and the flow under the vortex sheet outboard of that turning point is uniform and parallel to the leading edge of the wing on narrow delta wings the conical symmetry persists almost to the trailing edge
CRAN	analytic study of induced pressure on long bodies of revolution with varying nose bluntness at hypersonic speeds analytic study of induced pressure on long bodies of revolution with varying nose bluntness at hypersonic speeds a systematic study of induced pressures on a series of bodies of revolution with varying nose bluntness has been made by using the method of characteristics for a perfect gas the fluid mediums investigated were air and helium and the mach number range was from 5 to 40 a study of representative shock shapes was also made flow parameters obtained from the blast wave analogy gave good correlations of induced pressures and shock shapes the induced pressure correlations yielded empirical equations for air and helium which cover the complete range of nose bluntness considered nose fineness ratios varied from 0 4 to 4 available experimental results were in good agreement with the characteristics solutions properties connected with the concept of hypersonic similitude enabled correlations of the calculations to be made with respect to nose shape mach number and ratio of specific heats
CRAN	bending of a square plate with two adjacent edges free and the others clamped or simply supported bending of a square plate with two adjacent edges free and the others clamped or simply supported the title problems were solved for the two cases 1 uniform transverse loading 2 a concentrated force at the free corner a function is chosen to exactly satisfy the biharmonic equation while the boundary conditions are enforced at a number of points plied at discrete points around the boundary for each of the four problems and the resulting 35 simultaneous equations were solved on an ibm 704 tables listing the values of deflection and bending moments are presented this paper provides useful information on the solution of these problems which are intractable by analytical methods
CRAN	an experimental investigation of the flow over blunt nosed cones at a mach number of 5 8 an experimental investigation of the flow over blunt nosed cones at a mach number of 5 8 shock shapes were observed and static pressures were measured on spherically blunted cones at a nominal mach number of 5 8 over a range of reynolds numbers per inch from 97 000 to 238 000 for angles of yaw from 0 to 8 six combinations of the bluntness ratios 0 4 0 8 and 1 064 with the cone half angles 10 20 and 40 were used in determining the significant parameters governing pressure distribution the pressure distribution on the spherical nose for both yawed and unyawed bodies is predicted quite accurately by the modified newtonian theory given by where is the angle between the normal to a surface element and the flow direction ahead of the bow shock cone half angle was found to be the significant parameter in determining the pressure distribution near the nose cone junction and over the conical afterbody on the 40 spherical nosed cone models the flow overexpanded with respect to the taylor maccoll pressure in the region of the spherical conical juncture after which the pressure returned rapidly to the taylor maccoll value for models with smaller cone angles the region of minimum pressure occurred farther back on the conical portion of the model and the taylor maccoll pressure was approached more gradually the shape of the pressure distributions as described in nondimensional coordinates was independent of the radius of the spherical nose and of the reynolds number over the range of reynolds number per inch between 97 x 10 and 2 38 x 10 integrated results for the pressure foredrag of the models at zero yaw compared very closely with the predictions of the modified newtonian approximation except for models with large cone angles and small nose radii where the drag approaches the value given by the taylor maccoll theory for sharp cones
CRAN	cantilever plate with concentrated edge load cantilever plate with concentrated edge load the author gives by the method of finite differences an approximate solution of the problem of a finite length of a cantilever plate which bears a concentrated load at the longitudinal free edge all the boundary conditions are taken into account and the plate action is determined approximately at all points of the plate the author points out that a secondary maximum transverse stress occurs at the clamped edge nearest the loading point and that the longitudinal stress is greatest directly under the loading point
CRAN	the solution of elastic plate problems by electrical analogies the solution of elastic plate problems by electrical analogies a dynamic analogy method for the solution of elastic plate problems is described in this paper the electrical circuits developed here can be set up and studied on an electric analog computer problems involving deflections under constant load transient vibrations or normal modes can be solved in this way the method of applying boundary conditions to plates with irregular edges is given together with a detailed description of the representation of the boundary conditions for a rectangular variable thickness plate solutions that have been obtained on the cal tech electric analog computer are presented for the static deflections and normal modes of a rectangular cantilever plate
CRAN	preliminary analysis of axial flow compressors having supersonic velocity at the entrance of the stator preliminary analysis of axial flow compressors having supersonic velocity at the entrance of the stator a supersonic compressor design having supersonic velocity at the entrance of the stator is analyzed on the assumption of two dimensional flow the rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests the results of the analysis show that compression ratios per stage of 6 to 10 can be obtained with adiabatic efficiency between 70 and 80 percent consideration is also given in the analysis to the starting stability and range of efficient performance of this type of compressor the desirability of employing variable geometry stators and adjustable inlet guide vanes is indicated although either supersonic or subsonic axial component of velocity at the stator entrance can be used the cascade test results suggest that higher pressure recovery can be obtained if the axial component is supersonic
CRAN	flow of gas through turbine lattices flow of gas through turbine lattices paper is a translation of chap 7 of the book technical gas dynamics see amr 9 rev 1869 the topics treated are best shown by the list of paragraph headings they are 7 1 geometrical and gasdynamical parameters of the lattices fundamentals of flow through lattices 7 2 theoretical methods of investigation or plane potential flow of incompressible fluid through a lattice 7 3 electro hydrodynamic analogy 7 4 forces acting on an airfoil in a lattice theorem of joukowsky for lattices 7 5 fundamental characteristics of lattices 7 6 friction losses in plane lattice at subsonic velocities 7 7 edge losses in plane lattice at subsonic velocities 7 8 several results of experimental investigations of plane lattices at small subsonic velocities 7 9 flow of gas through lattice at large subsonic velocities critical mach number for lattice 7 10 profile losses in lattices at large subsonic velocities 7 11 flow of a gas through reaction lattices at supersonic pressure drops 7 12 impulse lattices in supersonic flow 7 13 losses in lattices at near sonic and supersonic velocities 7 14 computation of angle of deflection of flow in overhang section of a reaction lattice at supersonic pressure drops 7 15 characteristic features of three dimensional flow in lattices
CRAN	the quasi cylinder of specified thickness and shell loading in supersonic flow the quasi cylinder of specified thickness and shell loading in supersonic flow the methods of the operational calculus are used to obtain a linear approximation to the shape of the mean camber surface of a quasi cylinder in a supersonic flow in terms of its shell thickness and loading distributions the analysis deals with a generalised quasi cylinder that is one which although lying close to a mean cylinder need not possess axial symmetry the quasi cylinder is also permitted to be within the small disturbance field of other separate components e g a centre body because the linearised theory is inadmissable for internal duct flows close to and beyond the first reflected characteristic cone the present solution is likewise invalid close to and beyond the position where this characteristic meets the mean cylinder the work given here enables the camber shapes of ring wings which have been used theoretically to reduce or even nullify the wave drag of a central slender body to be found an example illustrates the general method
CRAN	a description of the r a e high speed supersonic tunnel a description of the r a e high speed supersonic tunnel an account is given of the high supersonic speed tunnel now nearing completion the design philosophy is reviewed the principal features are described and some of the more interesting development problems are noted
CRAN	calibration of the flow in the mach 4 working section of the 4ft x 3ft high supersonic speed wind tunnel at rae bedford calibration of the flow in the mach 4 working section of the 4ft x 3ft high supersonic speed wind tunnel at rae bedford mach number and flow angle distributions in the working section of the mach 4 nozzle of the 4 ft x 3 ft high supersonic speed wind tunnel are presented for a range of total pressure and humidity
CRAN	free flight measurements of the zero lift drag and base pressure on a wind tunnel interference model m 0 8   1 5 free flight measurements of the zero lift drag and base pressure on a wind tunnel interference model m 0 8   1 5 five free flight models were flown to measure the zero lift drag and body base pressure on a standard wind tunnel interference model over a mach number range of 0 84 to 1 48 roughness bands on the wings and body of the model are shown to produce a small but definite increase in the zero lift drag at all mach numbers the measured drag is in fair agreement with corresponding measurements made in various transonic tunnels with differences that could plausibly be explained as the effects of tunnel interference the effect of a simulated wind tunnel support sting is shown to increase the base pressure the discrepancy between models with and without a sting is greatest at subsonic speeds and progressively decreases with increasing mach number until at m 1 4 the sting has no effect on base pressure
CRAN	theoretical damping in roll and rolling moment due to differential wing incidence for slender cruciform wings and wing body combinations theoretical damping in roll and rolling moment due to differential wing incidence for slender cruciform wings and wing body combinations a method of analysis based on slender wing theory is developed to investigate the characteristics in roll of slender cruciform wings and wing body combinations the method makes use of the conformal mapping processes of classical hydrodynamics which transform the region outside a circle and the region outside an arbitrary arrangement of line segments intersecting at the origin the method of analysis may be utilized to solve other slender cruciform wing body problems involving arbitrarily assigned boundary conditions in the present report the application of the method has shown differential incidence of both pairs of opposite surfaces of the cruciform wing body combinations are practically independent of the body diameter maximum span ratio up to a value of this ratio of 0 3 arrangement is only 62 percent greater than that for a corresponding planar wing body combination dence of both pairs of the opposing surfaces of the cruciform wing body arrangement is only 52 percent greater than that for a corresponding planar wing body combination unit surface deflection of the cruciform wing body arrangement having four equally deflected panels is therefore 94 percent of the corresponding planar wing body combination
CRAN	application of two dimensional vortex theory to the prediction of flow fields behind wings of wing body combinations at subsonic and supersonic speeds application of two dimensional vortex theory to the prediction of flow fields behind wings of wing body combinations at subsonic and supersonic speeds a theoretical investigation has been made of a general method for predicting the flow field behind the wings of plane and cruciform wing and body combinations at transonic or supersonic speeds and slender configurations at subsonic speeds the wing trailing vortex wake is represented initially by line vortices distributed to approximate the spanwise distribution of circulation along the trailing edge of the exposed wing panels the afterbody is represented by corresponding image vortices within the body two dimensional line vortex theory is then used to compute the induced velocities at each vortex and the resulting displacement of each vortex is determined by means of a numerical stepwise integration procedure the method was applied to the calculation of the position of the vortex wake and the estimation of downwash at chosen tail locations behind triangular wing and cylindrical body combinations at supersonic speeds the effects of such geometric parameters as aspect ratio angle of attack and incidence ratio of body radius to wing semi span and angle of bank on the vortex wake behind wings of wing body combinations were studied the relative importance of wing vortices the corresponding image vortices within the body and body crossflow indetermining the the total downwash was assessed at a possible tail location it was found that the line vortex method of this report permitted the calculation of vortex paths behind wings of wing body combinations with reasonable facility and accuracy a calculated sample wake shape agreed qualitatively with one observed experimentally and sample results of the line vortex method compared well with an available exact crossflow plane solution an empirical formula was derived to estimate the number of vortices required per wing panel for a satisfactory computation of downwash at tail locations it was found that the shape of the vortex wake and the ultimate number of rolled up vortices behind a wing depend on the circulation distribution along the wing trailing edge for the low aspect ratio plane wing and body combinations considered it appeared that downwash at horizontal tail locations is largely determined except near the tail body juncture by the wing vortices alone for small ratios of body radius to wing semispan and by the body upwash alone for large values of that ratio
CRAN	contributions of the wing panels to the forces and moments of supersonic wing body combinations at combined angles contributions of the wing panels to the forces and moments of supersonic wing body combinations at combined angles a wind tunnel investigation was conducted at a mach number of 1 96 and at reynolds numbers based on the mean aerodynamic chord of the exposed wing of 0 36 and 1 03 million to determine the normal forces pitching moments and rolling moments contributed by each wing panel of a cruciform wing and body combination over a wide range of combined angles of pitch and roll the wings were triangular of aspect ratio 2 and the body was an ogive cylinder combination the effects of forebody length and roughness and of the presence of the adjacent panels on these panel contributions were determined the results of the investigation show that large changes in the panel forces and moments can occur as the result of combined angles a general theoretical method based on slender body and strip theories was found to yield results in good agreement with the wind tunnel measurements these comparisons indicate that the changes in the panel characteristics due to combined angles are caused primarily by a cross coupling between the side wash velocities due to angle of attack and sideslip and by the presence of forebody vortices due to crossflow separation it was found that an increase in forebody length increases the effect of the forebody vortices because of the dependence of the strength of these vortices on the forebody length
CRAN	application of similar solutions to calculations of laminar heat transfer on bodies with yaw and large pressure gradients in high speed flow application of similar solutions to calculations of laminar heat transfer on bodies with yaw and large pressure gradients in high speed flow an integral method for the rapid calculation of heat transfer distributions on yawed cylinders of arbitrary cross sectional shape and on bodies of revolution in high speed flows is developed for laminar boundary layers the method involves the quadrature of a function of the pressure distribution assumed given and satisfies the integral energy equation with the assumption of local similarity wherein the actual boundary layer profiles at every station are replaced by corresponding profiles from a family of similar solutions the method is compared with other local similarity methods and with experimental heat transfer data on a circular cylinder and on a body of revolution designed for large axial pressure gradients good agreement between theory and data is obtained and it is shown that the present integral method in both its complete and simplified form gives generally better agreement with the data than certain other local similarity methods numerical examples are presented showing that the effect of sweep and gas properties on heat transfer distribution is small
CRAN	heat transfer in planetary atmospheres at super satellite speeds heat transfer in planetary atmospheres at super satellite speeds the main purpose of this investigation is to examine the dependence of heat transfer in planetary atmospheres on the total enthalpy up to flight velocities of 50 000 ft sec where a large proportion of the atoms are ionized the total thermodynamic and transport property concept discussed by hirshfelder j chem phys 26 2 feb 1957 is used
CRAN	hypervelocity stagnation point heat transfer hypervelocity stagnation point heat transfer this analysis includes the specific contributions of atoms molecules tions are i partially ionized air can be approximated as a four component gas including n2 n n and e ii the gas is in local thermochemical equilibrium iii there is no charge separation iv thermal diffusion is neglected v no electrical or magnetic fields low re effects are neglected
CRAN	stagnation point heat transfer measurements at super satellite speeds stagnation point heat transfer measurements at super satellite speeds brief description of experiments performed by using shock tube techniques for measurement of the stagnation point heating of a blunt body over a stagnation enthalpy range of 650 to 900 corresponding to velocities between 32 000 ft per sec and 39 000 ft per sec respectively data thus provided are used for comparison with theory
CRAN	a factor affecting transonic leading edge flow separation a factor affecting transonic leading edge flow separation a change in flow pattern that was observed as the free stream mach number was increased in the vicinity of 0 8 was described in naca technical note 1211 by lindsey daley and humphreys the flow on the upper surface behind the leading edge of an airfoil at an angle of attack changed abruptly from detached flow with an extensive region of separation to attached supersonic flow terminated by a shock wave in the present paper the consequences of shock wave  boundary layer interaction are proposed as a factor that may be important in determining the conditions under which the change in flow pattern occurs when the mach number is high enough the attached flow pattern exists because then the shock wave is far enough behind the leading edge to keep the influence of the high pressure behind the shock wave from extending through the boundary layer to the immediate vicinity of the leading edge and affecting the flow there some experimental evidence in support of the importance of shock wave  boundary layer interaction is presented
CRAN	compilation of information on the transonic attachment of flows at the leading edge of airfoils compilation of information on the transonic attachment of flows at the leading edge of airfoils schlieren photographs have been compiled of the two dimensional flow at transonic speeds past 37 airfoils having variously shaped profiles some of which are related and vary in thickness and camber the data for these airfoils were analyzed to provide basic information on the flow changes involved and to determine factors affecting transonic flow attachment which is a transition from separated to unseparated flow at the leading edges of two dimensional airfoils at fixed angles of attack as the subsonic mach number is increased
CRAN	evaluation of high angle of attack aerodynamic derivative data and stall flutter prediction techniques evaluation of high angle of attack aerodynamic derivative data and stall flutter prediction techniques the problem of stall flutter is approached in two ways first using the m i t  naca airfoil oscillator the aerodynamic reactions on wings oscillating harmonically in pitch and translation in the stall range have been measured evaluated and correlated where possible with available published data with the purpose of providing empirical information where no aerodynamic theory exists the major effects of reynolds number airfoil shape and reduced frequency on the aerodynamic reactions have been reaffirmed no instances of negative damping were observed in pure translatory motion and the ranges of negative damping occurring in pure pitch had the same general trends noted by other experimenters data on the time average values in the stall range of both lift and moment are presented for the first time second the results of numerous experimental observations of stall flutter have been reviewed and the various known attempts at its prediction have been examined compared and extended the sharp drop in critical speed and change to a predominantly torsional oscillation usually associated with the transition from classical to stall flutter is apparently primarily but not entirely caused by the marked changes in moment due to pitch fairly good stall flutter predictions have been reported only when adequate empirical data for this aerodynamic reaction happened to be available for the desired airfoil shape reynolds number range and reduced frequency range a semiempirical method of predicting the variations of moment in pitch with airfoil shape reduced frequency initial angle of attack and amplitude of oscillation has been presented
CRAN	some effects of variations in several parameters including fluid density on the flutter speed of light uniform cantilever wings some effects of variations in several parameters including fluid density on the flutter speed of light uniform cantilever wings an experimental investigation has been made of some effects of variations in several parameters including fluid density on the flutter characteristics of light uniform cantilever wings the assortment of wings tested covered a variety of positions of the elastic axis and center of gravity and values of the aspect ratio of 8 6 and 4 the relative density parameter where k is representative of the ratio of fluid density to wing mass was varied over a range of values from 1 2 to nearly 14 special emphasis has been placed on the lower values the experimental investigation has been supplemented by an analytical investigation based on the two dimensional aerodynamic theory for incompressible flow in a few instances corrections for the effects of finite span have been made in general the theoretical results followed the trends indicated by experiment except at very low values of the relative density parameter for these low values the analytical considerations employed indicated a freedom from flutter not found experimentally at higher values of the flutter speed coefficient is shown to decrease with decreasing values of and to be nearly proportional to the inverse of the square root of the air density
CRAN	calculated and measured pressure distributions over the midspan section of the naca 4412 airfoil calculated and measured pressure distributions over the midspan section of the naca 4412 airfoil pressures were simultaneously measured in the variable density tunnel at 54 orifices distributed over the midspan section of a 5 by 30 inch rectangular model of the n a c a 4412 airfoil at 17 angles of attack ranging from  dash 20degree to 30degree at a reynolds number of approximately 3 000 000 accurate data were thus obtained for studying the deviations of the results of potential flow theory from measured results technique are presented it is shown that theoretical calculations made either at the effective angle of attack or at a given actual lift do not accurately describe the observed pressure distribution over an airfoil section there is therefore developed a modified theoretical calculation that agrees reasonably well with the measured results of the tests of the n a c a 4412 section and that consists of making the calculations and evaluating the circulation by means of the experimentally obtained lift at the effective angle of attack i e the angle that the chord of the model makes with the direction of the flow in the region of the section under consideration in the course of the computations the shape parameter is modified thus leading to a modified or an effective profile shape that differs slightly from the specified shape
CRAN	an approach to the flutter problem in real fluids an approach to the flutter problem in real fluids an approximate theory of airfoils in unsteady motion in a viscous fluid is proposed in which viscous effects are accounted for by relaxing the kutta condition and replacing it by a relation derived from experiments in steady flow applications here are limited to moderate viscous effects below the stall the possibility of one degree  of freedom flutter is discussed under this assumption the discussion is partly extrapolated to the domain of stall flutter some possibilities of further development of this theory for the stalled case are indicated
CRAN	on the application of mathieu functions in the theory of subsonic compressible flow past oscillating airfoils on the application of mathieu functions in the theory of subsonic compressible flow past oscillating airfoils an account is given of explicit solutions in terms of mathieu function functions of the problem of two dimensional subsonic compressible flow past oscillating airfoils the results are applied to the calculation of three dimensional corrections for the two dimensional theory and the effect of the incorporation of the three dimensional effects on the mathieu function solution of the two dimensional problem is shown the developments are formal and must be supplemented by an appreciable amount of numerical calculations before the theory can be applied to specific problems
CRAN	wake of a satellite traversing the ionosphere wake of a satellite traversing the ionosphere the particle treatment is applied to a study of the structure of the wake behind a charged body moving supersonically through a low density plasma for the case of a body whose dimensions are considerably smaller than a debye length a solution is obtained which is very similar in structure to the solution obtained by using the linearized fluid dynamics equation for the case of a disk whose radial dimensions are much larger than a debye length two conical regions are found in the wake at the surface of each of these cones over thicknesses of the order of a debye length the ion and electron densities are increased over their ambient values formulae for the electrohydrodynamic drag on a wire and on a large disk are obtained
CRAN	motion of thin bodies in a highly rarefied plasma motion of thin bodies in a highly rarefied plasma magnetic effects are considered negligible and the velocity of the body is in a range between the electron and positive ion thermal speeds the self consistent field approach is used in which the electron distribution is assumed to be maxwellian while the positive ion distribution function is given by the collision free boltzmann equation it is assumed that the ion reflection at the body surface is specular and the body is sufficiently thin so that the ion distribution function is a small perturbation of a maxwellian distribution the solution for the simple case of a dielectric body with a given surface charge as well as some general properties to be expected for a conducting body are given
CRAN	induction drag on a large negatively charged satellite moving in a magnetic field free ionosphere induction drag on a large negatively charged satellite moving in a magnetic field free ionosphere an induction drag experienced by a charged satellite during its traversal of the ionosphere has been theoretically postulated by several authors previous exact treatments of the problem are inapplicable to large systems and the semiempirical approach of jastrow and pearse may yield somewhat questionable results the present description initially considers the satellite as a completely permeable spherical shell of charge thus avoiding the difficult boundary conditions introduced by the exact linearized treatment the effects of permeability are then shown to be approximately removable by means of an iterative process a final result apparently valid to within an order of magnitude is obtained for the drag force arising solely from electrical effects its magnitude is considerably less than that obtained by jastrow and pearse
CRAN	interaction of a charged satellite with the ionosphere interaction of a charged satellite with the ionosphere the problem of the ion density distribution around a charged satellite has been treated by a numerical method which does not require linearization of the equations or restriction to infinitesimal objects however magnetic field effects were not considered and a number of other simplifying assumptions were required some sample calculations for spherical satellites are presented illustrating the general character of the satellite wake calculations of the so called charge drag were also made yielding results qualitatively similar to those previously obtained by jastrow and pearse
CRAN	some physical interpretations of magnetohydrodynamic duct flows some physical interpretations of magnetohydrodynamic duct flows this note presents some physical interpretations of magnetohydrodynamic duct flows with various boundary conditions viewed in the light of the effects of conducting walls on the pattern of electric current taking examples from published results on rectangular ducts the current patterns are illustrated in fig 1 for rectangular ducts having various combinations of conducting and nonconducting walls a uniform magnetic field being applied in the horizontal direction
CRAN	liapunovs methods in automatic control theory liapunovs methods in automatic control theory the work of a m liapunov and his theory of stability is discussed the second method of liapunov is shown to have applications for linear equations with real constant coefficients for a proof of the routh hurwitz criterion and linear equations with periodic coefficients practical examples include non linear stability problems of control and the functions have uses in other areas of control systems
CRAN	symmetric joukowsky airfoils in shear flow symmetric joukowsky airfoils in shear flow the velocity components of the fluid far from the airfoil are given by where c is the chord of the airfoil and k are constants u and v are velocity components in the directions of the coordinates x and y the solution is sought in the form of the stream function and satisfies laplaces equation a general expression for for vanishing disturbance velocities at points far from the origin is written and the flows due to a source a vortex and a solid circular cylinder in shear flow are considered as examples typical streamline patterns are shown for these cases from the eulerian equations of motion the author obtains the expression for in terms of the parameter and derivatives of the general form of is introduced and the appropriate solution for the pressure p is obtained by integration around a contour enclosing the body expressions are obtained analogous to the blasius formulae for the force and couple on any cylinder in this type of flow these formulae are applied to the case of a symmetrical joukowsky airfoil the method of conformal transformation is employed in the determination of the boundary condition of tangential flow at the airfoil surface must be satisfied by the total flow in the airfoil plane but this condition leads to a boundary condition for in the transformed plane the kutta joukowsky condition of finite velocity at the trailing edge also leads to a condition on in this plane from these conditions and the general expression for the circulation and the strengths of the doublets and quadruplets required for the force and moment are determined hence the formulae for lift and moment coefficient are obtained these involve in addition to the usual potential flow terms terms proportional to the ten functions that appear in the expressions for the lift and moment coefficients are tabulated for values of the thickness ratio between 0 and 1 the aerodynamic center position and the coefficient of the moment about the aerodynamic center are also calculated and are presented graphically as functions of
CRAN	the influence of two dimensional stream shear on airfoil maximum lift the influence of two dimensional stream shear on airfoil maximum lift the cornell aeronautical laboratory is conducting a program of theoretical and experimental research on low speed aerodynamics as applied to stol and vtol aircraft the objective of this program is to re examine certain aspects of classical aerodynamic information in the light of low speed flight requirements with the aim of seeking aerodynamic processes which might be exploited to enhance law speed performance one aspect of propeller driven aircraft which has recently received increasing attention is the existence of strong gradients of longitudinal velocity or shear in the propeller slipstream this slipstream shear interacts with a wing surface and can alter the wing characteristics in theoretical treatments of a wing interacting with a propeller slipstream the first important simplification is the replacement of the slipstream with an ideal uniform jet free of all velocity gradients the application of these theories requires that one equate the actual slipstream to an effective uniform jet one method employed is to assume the uniform jet has a momentum flux equal to the average in the propeller slipstream these and similar procedures are well founded on momentum considerations however the implicit assumption is that the flow nonuniformity the shear does not influence the wing characteristics
CRAN	several approximate analyses of the bending of a rectangular cantilever plate by uniform normal pressure several approximate analyses of the bending of a rectangular cantilever plate by uniform normal pressure three methods of approximating the deflections and moments occurring in a rectangular cantilever plate subjected to uniform normal pressure over its entire surface are presented in this paper the first is the application of the well known finite difference procedure the second and third are collocation methods one based upon polynomial solutions of the lagrange equation the other employing mixed hyperbolic trigonometric terms satisfying this equation in the last two methods the boundary conditions are satisfied exactly along the clamped edge and at a finite number of points along the free edges of the plate the results obtained for the particular case of a cantilever plate with uniform normal load indicate that the use of a relatively small number of points in the collocation method yields values of deflections and moments that are in substantial agreement with those given by the finite difference procedure it cannot be concluded from these results that the collocation method using the assumed functions will give satisfactory results with fewer points than the finite difference method for cantilever plates with loading different from the one investigated
CRAN	modified cross lees mixing theory for supersonic separated and reattaching flows modified cross lees mixing theory for supersonic separated and reattaching flows re examination of the crocco lees method has shown that the previous quantitative disagreement between theory and experiment in the region of flow up to separation was caused primarily by the improper c k relation assumed a new c k correlation based on low speed theoretical and experimental data and on supersonic experimental results has been developed and found to be satisfactory for accurate calculation of two dimensional laminar supersonic flows up to separation a physical model which incorporates the concept of the dividing streamline and the results of experiment according to this physical model viscous momentum transport is the essential mechanism in the zone between separation and the beginning of reattachment while the reattachment process is on the contrary an essentially inviscid process this physical model has been translated into crocco lees languages using a semiempirical approach and approximate c k and f k relations have been determined for the separated and reattaching regions the results of this analysis have been applied to the problem of shockwave laminar boundary layer interaction and satisfactory a study of separated and reattaching regions of flow has led to quantitative agreement with experiment has been achieved
CRAN	a study of flow fields about some typical blunt nosed slender bodies a study of flow fields about some typical blunt nosed slender bodies complete inviscid flow fields about three model axisymmetric configurations have been determined numerically configurations decreasing bluntness and flight conditions have been selected so as to indicate separately effects of nose shape drag coefficient flight mach number and thermodynamic behavior of the gas either ideal calorically perfect gas or air in equilibrium dissociation results are presented for thirteen cases particular attention is devoted to interpretation and when possible correlation of pressure distributions on and shock shapes about the cylindrical afterbodies it is found that a the correlation of pressure distributions on bodies having nonspherical noses involves interpretive modifications of the law suggested by blast wave analogy also shocks about these bodies are not described by parabolae b for all configurations there is substantial influence of gas behavior on shock shape this however can be correlated in terms of the gas conditions along a generally defined streamline c the shock layer can generally be divided into two regions the first bound by the body and the aforementioned streamline the second delimited by this streamline and the shock wherein flow properties can either be approximated by simple laws or correlated d for each configuration knowledge of the complete flow field in one flight condition even pertaining to ideal gas flow can be used to estimate features of flows under general flight conditions including those where equilibrium dissociation is encountered
CRAN	on laminar boundary layer flow near a position of separation on laminar boundary layer flow near a position of separation singularities are considered in the solution of the laminar boundary layer equations at a position of separation a singularity of the type here considered occurred in a careful numerical computation by hartree for a linearly decreasing velocity distribution outside the boundary layer it may occur generally whenever it does occur the boundary layer equations cease to be valid at and near separation on the upstream side and also downstream of separation the work suggests that singularities may arise in the solution of non linear parabolic equations due to their non linearity the formulae found may help computers of laminar boundary layers who desire more than a rough solution to have an end point at which to aim
CRAN	a new series for calculation of steady laminar boundary layer flows a new series for calculation of steady laminar boundary layer flows a new and general method for solving problems of plane and steady laminar boundary layer flows in incompressible fluids with arbitrary outer pressure distribution is developed this method is based on the introduction of the dimensionless quantities as new independent spatial variables ordinates u x the given outer velocity distribution v the kinematic viscosity the solution of the boundary layer problem is then given as a power series in e with coefficient functions depending on n this series is a formally exact solution of the boundary layer problem the new series solution has the following qualities have the significance only of cartesian coordinates the influence of wall curvature being neglected in boundary layer theory the new coordinates are adjusted to the data of the special problem in any case of application the new variables represent a logical development of former efforts in the field of boundary layer flow calculation with other series solutions known for some special cases is that the leading term of the new series satisfies exactly the outer boundary condition at all cross sections along the wall therefore the succeeding terms give corrections only in the inner part of the boundary layer accordingly taking also no 1 into account the zero order term by itself gives a good approximation for the boundary layer flow
CRAN	on the solution of the laminar boundary layer equations on the solution of the laminar boundary layer equations the theory of the laminar boundary layer offers a means of determining the skin friction under the assumption of a given velocity distribution outside the boundary layer owing to the mathematical difficulties however exact solutions are possible only when the velocity distribution is expressed as a simple function of the distance along the surface more complicated velocity distributions necessitate recourse to the method of expansion in series or that of step by step calculations but the labor involved is too great for the methods to be of practical use approximate method due to pohlhausen 1921 which had long been recommended for general use gives a reasonably accurate solution in a region of accelerated flow but recently its adequacy in a region of retarded flow has been questioned separation of flow may actually occur where the solution of pohlhausen fails to give it more recently howarth solution which gives fairly reasonable results in a region of retarded flow howarths solution essentially consists in solving the boundary layer equations for the particular case in which the velocity u outside the boundary layer decreases linearly with the distance x measured along the surface and utilizing the solution by replacing the actual distribution of u by a circumscribing polygon of infinitesimal sides therefore it is assumed that the velocity distribution at any section depends on the velocity gradient du dx at that section only being affected by the conditions upstream only in so far as this affects the momentum thickness 0 in other words the velocity distribution across the boundary layer is determined by a parameter
CRAN	correlated incompressible and compressible boundary layers correlated incompressible and compressible boundary layers the boundary layer equations for a compressible fluid are transformed into those for an incompressible fluid assuming that the boundary is thermally insulating that the viscosity is proportional to the absolute temperature and that the prandtl number is unity various results in the theory of incompressible boundary layers are then taken over into the compressible theory in particular the existence of method for retarded flows is applied to determine the point of separation for a uniformly retarded main stream velocity a comparison with an exact solution is used to show that this method gives a closer approximation than does pohlhausens
CRAN	approximate methods fore predicting separation properties of laminar boundary layers approximate methods fore predicting separation properties of laminar boundary layers some new solutions for steady incompressible laminar boundary layer flow obtained by gortler have been used to test the accuracy of two methods which are commonly used to predict separation a modification of stratfords criterion for separation is given in this paper and is probably the most accurate and the simplest of all methods at present in use modified numerical functions are also given for thwaitess method of predicting the main characteristics of the boundary layer over the whole surface which improve the accuracy of the method
CRAN	photo thermoelasticity photo thermoelasticity this paper summarizes the optical and physical properties of the photoelastic model material paraplex p 43 over the temperature range from room temperature to  40 f descriptions are presented of techniques and equipment developed to obtain the modulus of elasticity the material fringe value and the thermal expansion coefficient as a function of temperature experimental investigations were conducted into the plane stress problems of a disk contracting upon an elastic inclusion and the transient thermal stress field produced by a temperature differential suddenly applied to the upper edge of a long beam the data are correlated with theory using the material properties obtained in the calibration phase also included are photographic results of an exploratory investigation of the thermal shock phenomenon produced by the sudden application of a temperature differential upon plastic beams of various length depth ratios
CRAN	physical properties of plastics for photo thermoelastic investigation physical properties of plastics for photo thermoelastic investigation the optical and physical properties of paraplex p43 castolite and epoxy resin hysol 6000 op which are potentially of interest in photothermoelastic investigations were investigated over a temperature range from 100 to  60 f results on the thermal expansion coefficient the material fringe value and the modulus of elasticity as functions of temperature are presented also evaluated were thermal properties of importance in heat conduction photothermoelastic figures of merit which rate the optical sensitivity of materials in photothermoelastic applications as well as a new method to determine this figure in a relative manner are presented
CRAN	flow studies on flat plate delta wings at supersonic speeds flow studies on flat plate delta wings at supersonic speeds an experimental study has been made to investigate some aspects of the nature of the flow around delta wings vapor screen pressure distribution and ink flow studies were made at a mach number of 1 9 on a series of semispan delta wing models with slender wedge airfoil sections and very sharp leading edges the models had semiapex angles ranging from 5 to 31 75 separated regions of vorticity existed along the chords of all the wings in the series tested concentrated vortex cores were found only on wings of very small semiapex angles for wings with medium and large semiapex angles the separated vorticity was concentrated in a region extending over the outboard part of the span and lying close to the wing upper surface the results show that theoretical aerodynamic calculations such as those in naca tn 3430 utilizing a single separated vortex pair above the wing upper surface to represent the separated vorticity can be applied at supersonic speeds for very slender wings
CRAN	slender delta wings with sharp edges at zero lift slender delta wings with sharp edges at zero lift several slender wings of delta planform with sharp edges have been investigated theoretically at zero lift at subsonic and at supersonic speeds most of the wings have diamond shaped cross sections and are intended to lead to a type of flow with leading edge separation in the lifting condition the pressure distributions and overall normal pressure drags resulting from various theoretical methods are compared with one another and some discussion is included concerning the possibility of achieving the results calculated for an inviscid stream in a real flow in the presence of a viscous layer around the body
CRAN	development of the vapour screen method of flow visualization in the 3ft tunnel at rae bedford development of the vapour screen method of flow visualization in the 3ft tunnel at rae bedford the vapour screen method of flow visualisation in supersonic wind tunnels is outlined and the development of a suitable technique for use in the 3 ft tunnel described together with the associated optical and photographic equipment the results of tests to determine the humidity required to produce an optimum density of fog in the working section over the mach number range temperature discussed numerous vapour screen photographs of the flow over and behind delta wings are included and some comparisons made with the corresponding surface oil flow patterns the process of condensation the physical and optical properties of the resulting fog and the formation of the vapour screen picture are all considered in some detail the effects of humidity on the mach number and static pressure in the working section were investigated and the results are compared with theoretical estimates at a nominal mach number of 2 0 it is shown that the adverse effects of condensation on the flow at high mach numbers may be alleviated by the use of liquids with a lower latent heat of evaporation than water and some results obtained at a mach number of the possibility of extending the vapour screen technique to transonic and subsonic speeds is also considered and some results obtained at a mach number of 0 85 are included
CRAN	thin airfoil theory based on approximate solution of the transonic flow equation thin airfoil theory based on approximate solution of the transonic flow equation the present paper describes a method for the approximate solution of the nonlinear equations of transonic small disturbance theory although the solutions are nonlinear the analysis is sufficiently simple that results are obtained in closed analytic form for a large and significant class of nonlifting airfoils application to two dimensional flows with free stream mach number near 1 leads for instance to general expressions for the determination of the pressure distribution on an airfoil of specified geometry and for the shape of an airfoil having a prescribed pressure distribution and gives furthermore the correct variation of pressure with mach number at mach number 1 for flows that are subsonic everywhere the method yields a pressure correction formula that is more accurate than the prandtl glauert rule and compares favorably with existing higher approximations for flows that are supersonic everywhere the method yields the equivalent in transonic approximation of simple wave theory results obtained by application of these general expressions are shown to correspond closely to existing solutions and to experimental data for a wide variety of airfoils
CRAN	a refinement of the linearised transonic flow theory a refinement of the linearised transonic flow theory a new method is proposed to calculate the velocity and pressure distributions around a thin symmetrical aerofoil or a slender body of revolution flying at transonic speed it is essentially a refinement of the linearized transonic flow theory due to oswatitsch and maeder such that a correction term is introduced to take account of the nonlinear character of the transonic flow as examples of application a symmetrical circular arc aerofoil and a circular arc body of revolution in the sonic flow are dealt with and the results are found to be in good agreement with experiments except for the rear portion in the latter case
CRAN	linearised transonic flow about slender bodies at zero angle of attack linearised transonic flow about slender bodies at zero angle of attack the simple linearized transonic flow theory as originally proposed by oswatitsch and keune 1 and by the present authors 2 is improved by considering and partially correcting its error in this manner a theory which is easy to apply and which should be valid for a great number of smooth bodies is obtained this improved theory predicts shock waves in the lower transonic regions it is applied to a number of significant body and airfoil shapes and its predictions are compared with experiments and results of other theoretical investigations
CRAN	some notes for the small disturbance linear theory of the method of local linearisation of the flow over an airfoil at mach number of unity some notes for the small disturbance linear theory of the method of local linearisation of the flow over an airfoil at mach number of unity in this paper the pressure distribution at the surface of a symmetrical non lifting aerofoil with free stream mach number of unity has been investigated by means of the small disturbance linear theory or the method of local linearization and by comparing with the calculated results based on an hodograph method the accuracy of these approximate methods has been evaluated moreover when these approximate methods are used for the calculation of the pressure coefficient some notes necessary to obtain more correct results have been discussed
CRAN	some notes for the small disturbance linear theory of the method of local linearisation of the flow over an airfoil at mach number of unity some notes for the small disturbance linear theory of the method of local linearisation of the flow over an airfoil at mach number of unity in this paper the pressure distribution at the surface of a symmetrical non lifting aerofoil with free stream mach number of unity has been investigated by means of the small disturbance linear theory or the method of local linearization and by comparing with the calculated results based on an hodograph method the accuracy of these approximate methods has been evaluated moreover when these approximate methods are used for the calculation of the pressure coefficient some notes necessary to obtain more correct results have been discussed
CRAN	waves in supersonic flow waves in supersonic flow in this chapter we shall mainly consider problems of steady two  dimensional plane supersonic flow using the fact that in this case there is a steady wave system we shall find solutions by an indirect approach that is we shall first study the conditions under which simple stationary waves may exist in the flow and then find the flow boundaries to which they correspond or which may be fitted to them in this procedure the limited upstream influence in a supersonic field is very helpful for it allows flows to be analyzed or constructed step by step which is a method that is not possible in the subsonic case
CRAN	freeman method freeman method the freeman method ref 26 is similar to chesters method in that the newtonian plus centrifugal solution eq with the von mises transformation a method of successive approximations is applied to both plane and axially symmetric blunt nosed bodies for small and infinite free stream mach number formulas for the streamlines shock shape and pressure distribution are determined to this approximation a number of special shapes are treated in ref 26 and in certain cases the theory has a singular point where the first approximation to the pressure vanishes that is for a sphere see eq 7 113 as in chesters method the theory is not applicable where the pressure becomes too small
CRAN	laminar mixing of a compressible fluid laminar mixing of a compressible fluid a theoretical investigation of the velocity profiles for laminar mixing of a high velocity stream with a region of fluid at rest has been made assuming that the prandtl number is unity a method which involves only quadratures is presented for calculating the velocity profile in the mixing layer for an arbitrary value of the free stream mach number detailed velocity profiles have been calculated for free stream mach numbers of 0 1 2 3 and 5 for each mach number velocity profiles are presented for both a linear and a 0 76 power variation of viscosity with absolute temperature the calculations for a linear variation are much simpler than those for a 0 76 power variation it is shown that by selecting the constant of proportionality in the linear approximation such that it gives the correct value for the viscosity in the high temperature part of the mixing layer the resulting velocity profiles are in excellent agreement with those calculated by a 0 76 power variation
CRAN	the velocity distribution in the laminar boundary layer between parallel streams the velocity distribution in the laminar boundary layer between parallel streams a method is given for obtaining the solution of the laminar boundary layer equations for the steady flow of a stream of viscous incompressible fluid over a parallel stream of different density and viscosity an approximate solution is also obtained by means of the momentum equation it is shown that the solutions depend only on the ratio of the velocities of the two streams and on the product of the corresponding density and viscosity ratios numerical results are given in the case where the lower fluid is at rest for four values of and also when for one non zero value of the velocity ratio
CRAN	the blasius equation with three point boundary conditions the blasius equation with three point boundary conditions the blasius equation subject to three point boundary conditions describing the interaction between two parallel streams is solved by way of a series in terms of ascending powers of the ratio equals u1  dash u2 u1 where the u1s are the outer streams velocities the first three terms of the series are analytically expressed in terms of the repeated integrals of the complementary error function im erfc and of the repeated integrals of the square of the successive integrals of the complementary error function jmin erfc n these functions often appear in problems leading to extended heat conduction type of equations a recurrence formula for jmin erfc n is established and formulae relating the functions in erfc  dashn and jmjn erfc to available tabulated values of the functions in erfc n are derived the first three approximations to the blasius function and to its first two derivatives are also presented in tabulated form with four significant figures test on the convergence of the series has been made by comparison with some exact solutions obtained by high speed computing machine the comparison extended to the physically essential quantities shows that second and first derivatives yield extremely accurate results the errors in the first two derivatives of the blasius functions are always contained within less than one per cent
CRAN	laminar boundary layers at the interface of co current parallel streams laminar boundary layers at the interface of co current parallel streams the approximate solution of keulegan 1 for the steady flow of a stream of viscous incompressible fluid over another at rest is extended to the case where both fluids are moving co current but at different velocities this solution utilizes a sextic polynomial for the velocity distribution in the boundary layers the solutions depend only on the ratio of the velocities of the two streams and on the product of the corresponding viscosity and density ratios numerical results are given for seven values of at one value of lock 2 has published an exact solution with a numerical result for and the sextic polynomial solution is evaluated f40umerical result for and the sextic indicates that in general the sextic polynomial is more accurate than the quartic polynomial but that the advantage is not great
CRAN	tabulation of the blasius function with blowing and suction tabulation of the blasius function with blowing and suction authors tabulate solutions of f ff 0 for the velocity distribution in a boundary layer for each solution f 0 0 the third boundary condition is the specification of f 0 f n and its first three derivatives are tabulated to 5d in gaps of 0 1 in n for f 0  1 23849  1 2 0 05 0 5 0 1 1 5 introduction gives method of solution and physical meaning of boundary conditions etc locks amr cussed
CRAN	on an equation occurring in falkner and skans approximate treatment of the equation of the boundary layer on an equation occurring in falkner and skans approximate treatment of the equation of the boundary layer the differential analyser has been used to evaluate solutions of the equation y  yy with boundary conditions y y 0 at x 0 as which occurs in falkner and skans approximate treatment of the laminar boundary layer see abstract 1081 1932 a numerical iterative method has been used to improve the accuracy of the solutions and the results show that the accuracy of the machine solutions is about insufficient to specify a unique solution for negative values of a discussion of this situation is given and it is shown that for the application to be made of the solution the appropriate condition is that from below and as rapidly as possible as the condition that from below can be satisfied only for values of greater than a limiting value whose value is approximately  0 199 and which is related to the point at which the laminar boundary layer breaks away from the boundary
CRAN	adiabatic wall temperature due to mass transfer cooling with a combustible gas adiabatic wall temperature due to mass transfer cooling with a combustible gas a recent technical note by sutton 1 with the above title discusses the influence of the burning of a transpiration coolant on the quantity of coolant necessary to maintain a given wall temperature the present note discusses the same problem in a way which has been found useful in calculating the burning rates of solid and liquid fuels 2 consider the transpiration cooling of a porous surface in a gas stream then a simple modification of the general mass
CRAN	mass transfer cooling of a laminary boundary layer by injection of a light weight foreign gas mass transfer cooling of a laminary boundary layer by injection of a light weight foreign gas analytical predictions are given for the development of the velocity temperature and concentration fields in a laminar air boundary layer on a flat plate in high speed dissipative flow the plate being considered porous and cooled by injection of hydrogen from its surface the admixture of hydrogen having a low density and high thermal capacity relative to air is shown to greatly diminish the skin friction and to markedly relieve the adverse thermal effects of intense aerodynamic heating under conditions of hypersonic flow
CRAN	a re examination of the use of the simple concepts for prediction the shape and location of detached shock waves a re examination of the use of the simple concepts for prediction the shape and location of detached shock waves a reexamination has been made of the use of simple concepts for predicting the shape and location of detached shock waves the results show that simple concepts and modifications of existing methods can yield good predictions for many nose shapes and for a wide range of mach numbers
CRAN	stagnation point shock detachment distance for flow around spheres and cylinder stagnation point shock detachment distance for flow around spheres and cylinder development of an analytical relation between shock detachment distance and free stream mach numbers results are presented graphically for shock detachment distance of cylinders and spheres in air
CRAN	the influence of two dimensional stream shear for airfoil maximum lift the influence of two dimensional stream shear for airfoil maximum lift the effects of stream velocity gradients on airfoil maximum lift are defined with experimental data obtained in a simulated two dimensional slipstream the experimental results show that when positioned near the slipstream plane of symmetry the airfoil maximum lift varies markedly with location in the slipstream in moving the airfoil from above to below the slipstream plane of symmetry through a total distance corresponding to the airfoil thickness force data and boundary layer observations show that boundary layer separation is delayed to higher angles of attack and the airfoil maximum lift is doubled it is concluded that the destalling effect observed in the non uniform slipstream is not associated with slipstream boundary interference but stems from the influence of the large local slipstream shear on airfoil characteristics the effects of uniform and nonuniform shear on airfoil lift and pressure distribution are discussed within the framework of existing first order small shear theory to show that these effects of shear tend to promote stall a pohlhausen calculation of the laminar boundary layer in a stream with shear is used to identify and to assess the effects of stream shear on boundary layer separation criteria it is demonstrated that these effects are negligibly small and that the uniform flow criterion applies it is concluded on the basis of the experimental data that the observed destalling phenomenon stems from a shear effect of higher order than those treated in the inviscid theories it is hypothesized that it is a second order effect fixed by the product of the stream shear and the derivative of the shear which was large in the present experiments
CRAN	linear heat flow in a composite slab linear heat flow in a composite slab the temperature is determined as a function of position and time in the case of linear heat conduction in a composite slab of ture throughout and the two external surface temperatures are considered to be prescribed functions
CRAN	similarity laws for aerothermoelastic testing similarity laws for aerothermoelastic testing the similarity laws for aerothermoelastic testing are presented in the range these are obtained by making nondimensional the appropriate governing equations of the individual external aerodynamic flow heat conduction to the interior and stress deflection problems which make up the combined aerothermoelastic problem for the general aerothermoelastic model where the model is placed in a high stagnation temperature wind tunnel similitude is shown to be very difficult to achieve for a scale ratio other than unity the primary conflict occurs between the free stream mach number reynolds number aeroelastic parameter heat conduction parameter and thermal expansion parameter means of dealing with this basic conflict are presented these include 1 looking at more specialized situations such as the behavior of wing structures and of thin solid plate lifting surfaces and panel flutter where the aerothermoelastic similarity parameters assume less restrictive forms 2 the use of incomplete aerothermoelastic testing in which the pressure and or heating rates are estimated in advance and applied artificially to the model and 3 the use of restricted purpose models investigating separately one or another facet of the complete aerothermoelastic problem some numerical examples of modeling for the general aerothermoelastic case as well as for the specialized situations mentioned in 1 above are given finally extension of the aerothermoelastic similarity laws to higher speeds and temperatures is discussed
CRAN	theory for supersonic two dimensional laminar base type flows using the crocco lees mixing concepts theory for supersonic two dimensional laminar base type flows using the crocco lees mixing concepts a separated flow field in which the incoming boundary layer is undisturbed up to the separation point is defined as a base type flow examples are the flows over a blunt base and over a backward facing step the crocco lees theory is applied to the supersonic two dimensional laminar base type flows defined above the separated flow is divided into a mixing region and a recompression or reattachment region calculations of base pressure show its dependence on the mach number and on two reynolds number dependent variables and it is shown that existing base pressure data can be explained by these results
CRAN	a reaction rate parameter for gasdynamics of a chemically reacting gas mixture a reaction rate parameter for gasdynamics of a chemically reacting gas mixture presented note proposes a linearized reaction rate parameter which is applicable to any reacting gas mixture provided all the pertinent reactions and their rate constants are known at the thermodynamic conditions under consideration linearizing is achieved by expanding equation of rate of chemical reaction in a taylor series and neglecting higher order terms author announces that tables of linearized reaction rate parameters for dissociated and slightly ionized air are now in preparation at the space sciences laboratory general electric co msvo comparison of preliminary results with exact calculations published by hall i g et al inviscid hypersonic air flows with coupled non equilibrium processes ias paper 62 67 30th annual meeting new york jan 1962 indicates good agreement
CRAN	on calculation of the laminar separation point and results of certain flows on calculation of the laminar separation point and results of certain flows paper studies compressible laminar boundary layer in adverse pressure gradient after mentioning mathematical instabilities in howarths and like solutions authors quote equation from one of the references based on the assumptions that zero heat transfer and y 1 4 thence authors compute nondimensional distances to separation comparing with solutions by other workers results are interesting though reviewer feels rather unhappy about approximations leading to eq 4 more detailed justifications should have been given thus we have the statement ber as surely a fuller discussion of effects of letting is warranted typography in eqs 2 and 3 is rather confusing and there is a typographical error in heading to table 2
CRAN	normal shock relations in magnetohydrodynamics normal shock relations in magnetohydrodynamics the magnetic field vector is perpendicular to the flow direction thus for normal shocks there is no change of flow direction through the shock front this class of shocks is included in investigations by several authors five are referred to here but the presentation here is thought to be especially convenient all downstream quantities are given in terms of upstream flow conditions including the upstream ratio of alfven speed to sound speed and the shock strength density ratio
CRAN	on the close relationship between turbulent plane couette and pressure flows on the close relationship between turbulent plane couette and pressure flows author studies the velocity profiles measured by others in plane and turbulent couette flow such as is induced in parallel channels of which one of the walls moves in its own plane he finds these profiles to be satisfactorily describable in terms of the seventh power law which was originally set up for plane and turbulent pressure flow in channels where both walls are stationary further he finds the shear law for pressure flow to be applicable also to the couette flow in a similar range of reynolds number r no attempt is made in this concise contribution to put these findings on a firmer basis through a theoretical explanation
CRAN	prediction of ogive forebody pressures at angles of attack prediction of ogive forebody pressures at angles of attack various approximations are being suggested for obtaining surface pressures on arbitrary bodies at angle of attack this not presents a method for obtaining an approximate pressure distribution over the lower surface of an ogive forebody at angle of attack by utilizing the calculated pressures for zero angle of attack
CRAN	real gas laminar boundary layer skin friction and heat transfer real gas laminar boundary layer skin friction and heat transfer the laminar boundary layer equations have been integrated for the case of a flat plate over a wide range of free stream enthalpies and velocities and over a wide range of enthalpies of the gas at the wall the range of free stream velocities extended up to 25 000 ft sec at low free stream enthalpies corresponding to local conditions on a slender body traveling at high speeds at low free stream velocities the range of free stream enthalpies extended up to 400 000 btu slug corresponding to the local conditions on a blunt body traveling at speeds up to 25 000 ft sec the gas was assumed to be in thermodynamic equilibrium at each point in the boundary layer and diffusion effects were neglected the solutions to the boundary layer equations were carried out on a high speed digital computing machine both skin friction and heat transfer coefficients being obtained from the computations before presenting the results the t method of rubesin and johnson for computing skin friction coefficients for the perfect gas case is reviewed for the real gas case the average temperature t is replaced by the average enthalpy h and the h method is then used to compute skin friction coefficients these values are in excellent agreement with the computing machine results it was found that the recovery factor for the real gas case can be approximated by the best results for the cases considered being obtained if a value of pr corresponding to the enthalpy h is used using this recovery factor and reynolds analogy heat transfer rates can be computed which with a few exceptions are within 5 percent of values obtained from computing machine results
CRAN	axisymmetric viscous flow plast very slender bodies of revolution axisymmetric viscous flow plast very slender bodies of revolution axisymmetric viscous flow past unyawed very slender bodies of revolution is treated within the category of the perfect gas attention is paid especially to the effect of transverse curvature of the body from the transformed equations the similarity conditions are deduced and the parameter characterizing the effect of transverse curvature is obtained several numerical solutions of similarity equations for hypersonic flows are presented and upon the basis of these results the effect of the transverse curvature parameter is discussed a method of applying the local similarity approximation to obtain the approximate solution for nonsimilar cases is described as are practical applications to incompressible flow past a long cylinder and to hypersonic flow past a very slender cone comparison with experimental results shows fair agreement with calculations using the local similarity approximation in the present range of experimental flow conditions
CRAN	on similar solutions for strong blast waves and their application to steady hypersonic flow on similar solutions for strong blast waves and their application to steady hypersonic flow the general solution of the strong blast wave is found in the newtonian approximation  i e neglecting terms of order the expressions obtained for the pressure temperature density and velocity profiles are simple the results are applied to power law bodies in hypersonic flow using the equivalence principle higher order approximations for strong blast waves are investigated for the cases in which the shock layer is thin a simple pressure formula is found which constitutes an improvement upon the newton busemann formula and some of its applications are shown
CRAN	a theory of transonic aileron buzz neglecting viscous effects a theory of transonic aileron buzz neglecting viscous effects usaf sponsored analysis of the unsteady perturbations of two dimensional transonic flow around an airfoil where local supersonic regions terminated by shock waves are present in the vicinity of the airfoil viscous effects are neglected and a linearized theory of the perturbations due to harmonic oscillations of an aileron is developed a series solution for the pressure distribution is obtained and numerical results for the nonsteady hinge moment from the first approximation to the solution are presented as a result of flutter analysis a stability boundary for transonic aileron buzz is obtained comparison of the theoretical results with experimental observations shows satisfactory agreement
CRAN	theoretical and experimental investigation of thermal stresses in hypersonic aircraft wing structures theoretical and experimental investigation of thermal stresses in hypersonic aircraft wing structures a simple and relatively accurate analytic approximation is developed to determine the temperature and thermal stress distribution in aircraft wing structures theoretical investigations show that the results of the existing thermal stress theories which neglect the temperature gradient through the skin thickness may exceed in the range of higher biot numbers the true values by more than 30 percent refined photothermoelastic experiments verify these results and add another significant conclusion they indicate that thermal stresses in wing structures generated by a variable heat transfer coefficient coincide with the theoretical predictions which are based on a constant heat transfer coefficient as long as the latter represents the arithmetic average over the heating cycle and the variation is in the order of 10 percent however even much greater variations in the order of 100 percent produce only relatively small differences
CRAN	calculation of potential flow about bodies of revolution having axes perpendicular to the free stream direction calculation of potential flow about bodies of revolution having axes perpendicular to the free stream direction a general method is described for calculating with the aid of an electronic computer the potential flow about arbitrary bodies of revolution whose axes are perpendicular to the free stream direction when combined with the solution for the axisymmetric flow about these bodies this method makes it possible to calculate the pressure distribution on any body of revolution at angle of attack forward of any separated region of the flow and also to calculate the flow at points off the body surface after the basic equations of the method have been derived its accuracy is exhibited by comparison with analytic solutions for ellipsoids of revolution calculated pressure distributions are then compared with experimental data for a variety of bodies the agreement is quite satisfactory in all cases the calculated velocities for other selected bodies are presented to exhibit certain properties of this type of flow
CRAN	a closed form solution for the oscillations of a vehicle entering a planetary atmosphere a closed form solution for the oscillations of a vehicle entering a planetary atmosphere author considers the equation of the yawing motion of a missile derived with a series of customary assumptions and with the distance traveled as the independent variable his assumptions include the linearity of the aerodynamic forces the constancy of the aerodynamic coefficients with respect to mach number the absence of spin and the absence of gravity if to these assumptions one could add the common ballistic assumption of a constant air density the coefficients of this equation would have been con damped sinusoids in ballistics any slow variation of these coefstant and the solution would have been simply the exponentially ficients is usually treated by adding an approximate correction term to the damping rate which is spoken of as the wkb perturbation however with a body entering the planetary atmosphere the variation of the air density is apparently of greater essence this is a point not stated explicitly in this brief communication and the equation is of the type the author shows that with a series of further transformations the equation can be reduced to the form the solutions of which are confluent hypergeometric functions these functions are defined as series involving gamma functions and with a series of further assumptions can be reduced to laguerre polynomials and bessel functions it is certainly nice to have an exact solution to a problem which has heretofore been extensively treated by approximations and by the numerical approach this reviewer is puzzled however as to the practical significance of the proposed approach an idealization is of value in that it facilitates our understanding and the numerical approach in that it allows refinements of the problem freeing us from the necessity of idealizing but the proposed solution is certainly more difficult to refine than the original problem and it is certainly not simple the solution of the original equation is not the value of z but the various reverse transformations of z an evaluation of a series in practice must compete with the numerical approach and the equation suggested is of the zero viewing the problem afresh in the light of the computer revolution and without the constraints imposed by the prior art it seems at least equally easy to standardize the solutions of the original equation
CRAN	joule heating in magnetohydrodynamic free convection flows joule heating in magnetohydrodynamic free convection flows the steady fully developed laminar free convection flow of an electrically conducting fluid between two fully submerged open ended constant temperature vertical plates located in a constant uniformly distributed transverse magnetic field has been analyzed with the joule heating term retained in the energy equation analytic results are obtained such analytic results are useful in estimating the actual magnitude of the influence of joule heating as well as a qualitative description of the manner in which it alters the temperature and flow fields the present result confirms the usual practice that the influence of joule heating is negligibly small
CRAN	stagnation point shock detachment of blunt bodies in supersonic flow stagnation point shock detachment of blunt bodies in supersonic flow presentation of stagnation point shock detachment distances determined by the exact numerical method of gravalos edelfelt and emmons the results are compared with those from the previously published methods of van dyke and gordon li and geiger and serbin and with experimental data
CRAN	on squires test of the compressibility transformation on squires test of the compressibility transformation discussion of a previous application by squire of the authors compressibility transformation to the correlation of high speed boundary layer data for air and helium squires suggestion that the compressibility transformation is invalid is shown to be incorrect
CRAN	theoretical prediction of the transonic characteristics of airfoils theoretical prediction of the transonic characteristics of airfoils it is shown that the authors transonic flow airfoil theory can be used to estimate transonic drag rise and onset of  separation effects mach numbers without reference to experimental results a simple comparative method is applied to a series of airfoils and the results are analyzed to determine some of the design features of importance in transonic flow an improvement to this scheme is shown to give results in good agreement with experiment for both the first appearance of shock waves and the onset of separation effects application to finite swept wings is briefly considered and illustrated
CRAN	stability of compressible boundary layers induced by a moving wave stability of compressible boundary layers induced by a moving wave the problem of determining the stability of compressible viscous flows with nonzero surface velocities is formulated and is shown to be identical to that for conventional boundary layers with only a redefinition of the mach and reynolds numbers required specific consideration is given to the wall boundary layer behind a moving shock wave and the minimum critical reynolds numbers are obtained for various shock velocities the entire stability map is determined for the limiting case of a weak wave which is analogous to the rayleigh problem the minimum critical reynolds number is found to increase monotonically with shock velocity  i e with increasing surface cooling and stream mach number combined for the ratio of wall to stream velocity of 2 92 with shock mach number of 2 18 the flow is found to be infinitely stable to two dimensional disturbances experimental transition data do not follow the trends predicted by the theory in fact the transition reynolds numbers are orders of magnitude below the computed minimum critical reynolds numbers the lack of correlation between theory and experiment is attributed to disturbances which are external to the boundary layer
CRAN	transition measurements on cones in free flight ballistics range tests transition measurements on cones in free flight ballistics range tests navy sponsored experimental investigation of the location of boundary layer transition on sharp nosed cones having 10 total angles the ambient temperature in a portion of the aeroballistics range is varied so as to obtain different adiabatic recovery temperatures at a constant nominal mach number of 3 1 the location of transition is expressed as a transition reynolds number and results are presented graphically as a function of the ratio between the wall temperature and the adiabatic recovery temperature
CRAN	a note on havelocks shallow water wave resistance curves a note on havelocks shallow water wave resistance curves in the continuous quest for improved means of transportation attention is currently focused on the ground effect machine as there is no physical contact between the vehicle and the terrain over which it operates its performance should be similar over land and water however over water there is an additional resistance to motion due to the gravity wave system generated by the supporting or cushion pressure acting on the water surface estimates of this component can be made using the analysis of t h havelock it is the purpose of this note to present an ibm 650 digital computer solution of his equations as shown below these results differ from havelocks original results
CRAN	energy equation approximations in fluid mechanics energy equation approximations in fluid mechanics discussion of several forms of the energy equation and of their use for the study of the flow of nearly incompressible fluids
CRAN	a correlation of nose bluntness induced pressures on cylindrical and conical after bodies at hypersonic speeds a correlation of nose bluntness induced pressures on cylindrical and conical after bodies at hypersonic speeds van hise in his detailed study of the nose bluntness induced pressures on cylindrical afterbodies shows that starting a few nose diameters aft of the nose afterbody junction these pressures are correlated with the parameter as predicted by the blast wave analogy chernyi developed a modified form of the blast wave analogy which takes into account the addition of energy to the flow by a thin afterbody he showed that for thin afterbodies and hypersonic speeds the pressure distribution plotted as should correlate with the parameter the purpose of this note is to show that the above correlation techniques may be combined into a form such that pressures on cylindrical and conical afterbodies are correlated by one parameter
CRAN	a graphical approximation for temperatures and sublimation rates at surfaces subjected to small net and large gross heat transfer rates a graphical approximation for temperatures and sublimation rates at surfaces subjected to small net and large gross heat transfer rates considers a material acted upon by heat of conduction which changes its state by sublimation at the heated surface the derived method is most suitable under conditions of severe heating such as space vehicle re entry
CRAN	manoeuvring technique for changing the plane of circular orbits with minimum fuel expenditure manoeuvring technique for changing the plane of circular orbits with minimum fuel expenditure usaf supported discussion of the use of an intermediate elliptic orbit for changing the plane of a circular orbit values of the perigee and apogee velocities are calculated for the following cases the braking impulse supplied by grazing of the atmosphere and 3 re orbit with 90 of the braking impulse supplied in this manner
CRAN	tunnel tests on a double cascade to determine the interaction between the rotor and the nozzles of a supersonic turbine tunnel tests on a double cascade to determine the interaction between the rotor and the nozzles of a supersonic turbine experimental confirmation has been required that in a supersonic turbine the leading edges of the rotor governs the rotor incidence and hence the gas exit angle from the nozzles evidence has also been required that once the rotor incidence has been allowed for there is no adverse effect of the rotors on the nozzle flow even when the rotors have a large turning angle the present test cascade represented the stationary configuration of a turbine of 2 5 nozzle mach number and 74 swirl angle the rotors being designed to operate at 1 9 relative mach number and to provide a turning angle of 140 in the tests fully supersonic flow could be established through the system but the losses were fairly high and an increase in loss of about 25 per cent would have caused choking in the rotor
CRAN	quasi cylindrical surfaces with prescribed thickness distributions quasi cylindrical surfaces with prescribed thickness distributions a formula for the supersonic velocity field in terms of a given surface distribution of sources is applied to points lying in the surface an equation giving the camber shape of a quasi circular cylindrical surface in terms of a prescribed thickness distribution is derived and the half ring wing with prescribed thickness distribution is discussed as an example
CRAN	pressure measurements at supersonic speeds on three uncambered conical wings of unit aspect ratio pressure measurements at supersonic speeds on three uncambered conical wings of unit aspect ratio pressure measurements were made at mach numbers between 1 3 and 2 8 over a range of incidences on three simple models representing thick conical uncambered wings with sharp leading edges these tests form part of an investigation into the effects of thickness and camber on slender wings the aspect ratio of the models was unity in each case and the spanwise cross sections were bounded by the measured pressure distributions are presented along with overall lift and drag excluding skin friction and base drag obtained by integration
CRAN	pressure distributions and flow patterns on some conical shapes with sharp edges and symmetrical cross sections at m 4 0 pressure distributions and flow patterns on some conical shapes with sharp edges and symmetrical cross sections at m 4 0 results are given of a wind tunnel programme made to study the pressure distributions and flow patterns over a series of simple conical shapes at a mach number of 4 0 the results have been compared with various approximate theories and the limitations of these theories are discussed it is found that at this mach number leading edge separations still have an influence on the suction surface pressure and that this surface still makes a significant contribution to the overall forces
CRAN	self sustained oscillations of a system with non linear damping of a particular type self sustained oscillations of a system with non linear damping of a particular type the paper deals with self sustained oscillations of a dynamic system of single degree of freedom with linear restoring force and non linear damping force the latter is supposed to be a function of velocity representable by a simple polygonal graph such that the damping is negative at small velocities but becomes positive at velocities above a certain value on these assumptions a rigorous solution is presented including the equations of motion amplitude maximum velocity and period a very simple solution is obtained for the limiting case of vanishingly small damping an approximate solution by series in powers of damping ratio is worked out which gives a satisfactory accuracy for quite large values of
CRAN	free flight measurements of the dynamic longitudinal stability characteristics of a wind tunnel interference model m 0 92 to 1 35 free flight measurements of the dynamic longitudinal stability characteristics of a wind tunnel interference model m 0 92 to 1 35 the dynamic longitudinal stability characteristics of a standard wind tunnel interference model have been investigated in free flight over a mach number range of 0 92 to 1 35 measurements of lift curve slope and manoeuvre margin were obtained and are compared with results from transonic tunnel tests under low blockage conditions the analysis was extended to obtain damping derivatives to allow comparison to be made with possible future dynamic tests in wind tunnels on the standard shape
CRAN	reaction resisted shock fronts reaction resisted shock fronts it is shown that shock waves whose structure is determined solely by the effects of chemical reactions reaction resisted shock fronts are possible and completely analogous to relaxation   resisted waves a single dissociation reaction is considered and numerical results indicate that such waves could be observed experimentally bulk viscosities equivalent to reaction effects are possibly 10 or more times shear viscosity values examples are based on lighthills ideal dissociating gas
CRAN	heat conduction through a polyatomic gas heat conduction through a polyatomic gas a heat conduction problem is set up which in essence simulates the conditions arising when a plane shock wave reflects from a co planar solid boundary the gas is assumed to be polyatomic with one the quantity of primary interest is the temperature of the solid at the interface since this can be observed experimentally without much difficulty solutions are obtained for this quantity which cover a range of practically plausible relaxation times and wall effect parameters it is essential to include proper temperature jump boundary conditions for both active and relaxing or inert energy modes thus it is necessary to know accommodation coefficients for these modes of energy storage the temperature jump effects are found to dominate the interface solids temperature time history with relaxation effects playing a very secondary role the theoretical results are compared with some experimental observations and encouraging agreement is found as a result of this agreement it proves possible to estimate the accommodation coefficient for the active modes in this case for the combination platinum air the pressure being about 15 atmospheres the pressure sensitivity of accommodation effects is commented on
CRAN	base pressure at supersonic speeds in the presence of a supersonic jet base pressure at supersonic speeds in the presence of a supersonic jet the effects on base pressure of jet mach number free stream reynolds number and jet to base diameter ratio have been investigated experimentally it was found that for jet stagnation pressures greater than that required for the nozzle to reach its design mach number an increase of jet mach number reduced the base pressure similarly the base pressure increased with increase of the ratio of jet diameter to base diameter and at high jet stagnation pressures base pressures higher than free stream static pressure were found the base pressure was independent of free stream reynolds numbers greater than 2 x 10 per foot but increased with reduction of reynolds number below 2 x 10 per foot unsteady wave patterns were found when the jet mach number did not differ markedly from the free stream mach number and the jet had just reached its design conditions
CRAN	wing tail interference as a cause of magnus effects on a finned missile wing tail interference as a cause of magnus effects on a finned missile wing tail interference is shown to cause large magnus effects on a finned missile whose wings are deflected into an aileron setting a simple experimental method with water as the working medium is used to obtain low speed magnus data on a rolling missile the missile is a slender cruciform configuration with all movable wings and fixed tail fins magnus data are presented for angles of attack up to 15 and for the one high roll rate which accompanies a 30 aileron deflection angle of the wings tests conducted at zero roll rate but with the wing deflection maintained revealed large forces in the magnus direction thereby providing the basis for understanding magnus effects due to wing tail interference a semiempirical theory is proposed to explain the experimental data a simplified model of the wake behind the wings is introduced to predict tail interference factors good agreement with the data is obtained this magnus effect is opposite in direction to the classical magnus lift on a spinning cylinder it is much larger than either that effect or the one on a missile with only one set of fins wing tail interference is the predominant source of the effect roll rate only modifies the basic interference mechanism
CRAN	a note on application of transonic linearization to an airfoil with a round leading edge a note on application of transonic linearization to an airfoil with a round leading edge the profile of a symmetric airfoil of unit length with a round leading edge can be expressed in general as where p x has a finite slope at x 0 it is well known that the conventional sub  and supersonic linear theories of compressible flow break down in the neighborhood of such a round leading edge due to the failure of the small disturbance assumption the linearized transonic flow theory has the same short coming but if the determination of the sonic point on the airfoil plays an important role in any more advanced theory  e g spreiters local linearization method or hosokawas method of refinement  this theoretical barrier will become more serious because the sonic point is usually located in a flow region near the leading edge that may be greatly affected by the roundness
CRAN	laminar transitional and turbulent heat transfer to a cone cylinder flare body at mach 8 0 laminar transitional and turbulent heat transfer to a cone cylinder flare body at mach 8 0 an experimental investigation of the laminar transitional and turbulent heat transfer rates over a conical cylindrical flared body is presented regions of favorable zero and adverse pressure gradient on the body are investigated the experimental results are compared with the theories available in the literature the model chosen for this investigation is a cone cylinder flare configuration consisting of a 20 semivertex conical nose portion smoothly blended by a shoulder radius into a long cylindrical body and terminated by a smooth large radius flare the model was tested at a free stream mach number of 8 over a range of reynolds number from 0 3 x 10 to 1 6 x 10 per inch based on free stream conditions various stagnation to wall temperature ratios were obtained by cooling the model prior to the test with liquid nitrogen the stagnation to wall temperature ratios were 10 and 3 3 the theoretical predictions gave good results for the heat transfer rates in the laminar region and fair prediction in the transitional and turbulent regimes extending over the shoulder and forward portion of the cylindrical body over the aft portion of the cylinder and over the flare the predictions are only qualitatively correct and underestimate the heating rate by a factor as high as 3 conversely the flat plate reference enthalpy over the aft portion of the body but to increasingly overestimate the heating rates over the forward portion of the cylinder a modified equation for the heat transfer coefficient in the transitional and fully turbulent region based on the f p r e method is then presented this method gives good agreement with the experimental results presented over the entire range of transitional and turbulent flow from the results the following is concluded cooling the wall delayed transition by expanding the flow rapidly between the cone and the cylinder the transition reynolds number is reached very rapidly by making a smooth transition between the cylinder and the flare no separation occurred at the cylindrical flare junction the transitional and turbulent heat transfer in the presence of an adverse pressure gradient may be predicted with sufficient accuracy by the f p r e method
CRAN	approximate determination of position of the sonic line for a blunt body in hypersonic flow approximate determination of position of the sonic line for a blunt body in hypersonic flow the detached shock in front of a blunt body in hypersonic flow tends to acquire the shape of the frontal curvature of the body thus the curvature of the shock can be assumed to be the same as that of the body at least up to the sonic point point a fig 1 if the equation of curvature of the body is known the equation of curvature of the shock is also known in this paper with this assumption a method is described to determine the approximate position of the sonic line aob fig 1 the shock detachment distance is assumed known the method is of course general this can be applied to any detached shock provided its equation of curvature is known corresponding to that of the body for simplicity the detached shock is assumed to be circular in this paper and the procedure is outlined below with the assumption that the sonic line aob is parabolic
CRAN	stagnation point heat transfer in partially ionized air stagnation point heat transfer in partially ionized air comparison of heat transfer rates obtained by using transport properties recently reported by peng and pindroh with rates based on hansens thermodynamic and transport properties it is shown that the heat transfer rates based on the peng and pindroh data are 20 to 30 lower for the velocity range of 25 000 to 40 000 ft sec
CRAN	on hypersonic viscous flow over an insulated flat plate with surface mass transfer on hypersonic viscous flow over an insulated flat plate with surface mass transfer hypersonic viscous flow over an insulated flat plate with surface mass transfer is studied the tangent wedge approximation is used in the inviscid flow region and the integral method is applied to the treatment of the laminar boundary layer the law of surface mass transfer for the present analysis is derived a continuous transition of the pressure variation is achieved from the strong to the weak pressure interaction region first order formulas for the induced surface pressure and the skin friction coefficient are obtained for both the strong and weak pressure interaction regions results are compared with those calculated from other analyses
CRAN	leading edge attachment in transonic flow with laminar or turbulent boundary layers leading edge attachment in transonic flow with laminar or turbulent boundary layers the transonic flow round a two dimensional airfoil at incidence is often determined by the type of flow in the leading edge region if the flow separates at the leading edge at low speeds it is liable to attach as the speed increases often quite suddenly a review of this change with laminar or with turbulent boundary layers re emphasizes the importance of fixing transition when making model tests at transonic speeds in order to obtain flows closest to full scale conditions it is shown that similar airfoils with attached leading edge flow show transonic similarity upstream of the terminal shock
CRAN	note on the three point boundary layer problem for the blasius equations note on the three point boundary layer problem for the blasius equations in a recent paper a method was presented for obtaining higher accuracy in the numerical solution of the blasius equation with three point boundary conditions the well known blasius equation was previously developed in an investigation of the steady two dimensional incompressible boundary layer flow over a flat plate but it has been extensively used in investigating other fluid flow problems the three point boundary value problem is encountered in the theory of laminar mixing and in approximate analyses of separated and wake flows as noted in ref 1
CRAN	first order slip effects on the laminar boundary layer over a slender body of revolution with zero pressure gradient first order slip effects on the laminar boundary layer over a slender body of revolution with zero pressure gradient in reference 1 the analysis given by probstein and elliott for the zero pressure gradient constant wall temperature compressible laminar boundary layer with transverse curvature was extended to first order slip flow this extension was based on a double asymptotic expansion in a transverse curvature parameter and a slip parameter the expansion in ref 1 however was carried out with the parameter held constant for and a constant wall temperature is constant and e varies with x due to the dependence of the local body radius on x thus for arbitrary body shapes e will not be constant in the present note the analysis of ref 1 is re examined taking into account the variation of e
CRAN	some effects of injection of foreign gases in a decelerating laminar boundary layer in supersonic flow some effects of injection of foreign gases in a decelerating laminar boundary layer in supersonic flow the purpose of this research program was to investigate the effects of a diffusion field on a laminar boundary layer in a supersonic flow specifically helium nitrogen and argon were uniformly injected into the laminar boundary layer of a high speed flow in a tube with the objective of determining the effects of such injection on the pressure temperature and recovery factor distribution along and downstream of the injection region a continuously operating axially symmetric wind tunnel has been designed constructed and operated this tunnel consists of an air supply system a flowmeter an upstream stagnation tank a supersonic nozzle throat diameter 0 262 and exit diameter 1 400 a test section of variable length zero to 81 diameters test section diameter of 1 400 a downstream stagnation tank an exhaust system a foreign gas supply system and all necessary instrumentation the overall performance of this apparatus in terms of the design specifications was excellent the tunnel was instrumented with 109 thermocouples all temperatures except ambient temperatures were automatically measured and recorded by means of a self balancing recording potentiometer there was 29 pressure taps distributed along the tunnel 23 along the test section itself pressures were measured by means of an interconnected micromanometer and a vacuum referenced manometer system with overlapping ranges for all of the results reported herein the overall test section was 41 diameters in length composed of a porous test section approximately 7 2 diameters in length leading edge approximately 1 8 diameters from the nozzle exit plane and four nylon test sections of 8 diameters each
CRAN	an aerodynamic analysis for flutter in oseen type viscous flow an aerodynamic analysis for flutter in oseen type viscous flow oseens equations for unsteady flow are employed to obtain a linearized solution based on a discontinuous wake model the analysis is employed to estimate the viscous correction to unsteady lift and moment at large reynolds number if the asymptotic solution is not too slowly convergent the correction is of the order of the ratio of the logarithm of reynolds number to the reynolds number the theory is preliminary in nature as it is limited by the accuracy of oseens equations and is restricted to small angle of attack however it also shows that the generalized trailing edge condition for potential flow is reasonable and might predict the essential correction in a real fluid
CRAN	the flow about a moving body in the upper ionosphere the flow about a moving body in the upper ionosphere a particle approach is used to study the flow pattern around a body moving in the upper layers of the ionosphere the effects of distant encounters between charged particles dynamic friction and of the earths magnetic field are taken into account it is shown that when the magnetic lines of force are parallel to the direction of motion of the body there may be a marked concentration of charged particles in the vicinity of the body and a considerable fraction of the reflected or deflected charged particles may reimpinge on the body surface a numerical example is given for the size and shape of the charged  particle density contours in the flow field surrounding a circular disc and these are compared with the corresponding neutral particle contours
CRAN	pitch yaw stability of a missile oscillating in roll via the second method of lyapunov pitch yaw stability of a missile oscillating in roll via the second method of lyapunov the stability theory of a m lyapunov a popular topic in the u s s r is receiving increasing attention elsewhere this note describes lyapunovs second method very briefly and applies it to an aeronautical stability problem
CRAN	stagnation point shock detachment distance for flow around spheres and cylinders in air stagnation point shock detachment distance for flow around spheres and cylinders in air author discusses the problem of deflection of a cantilevered bar initially in the shape of a circular arc subjected to an arbitrarily inclined end load
CRAN	consideration of energy separation for laminar slip flow in a circular tube consideration of energy separation for laminar slip flow in a circular tube the energy separation for laminar low density nonunity prandtl number flow in circular cross section tubes is the topic of this note a conclusion is reached as to the effect of prandtl number on the velocity profiles for these flows however in order to reach valid quantitative conclusions the reviewer feels that more detailed analysis is in order and that the analysis as presented here is of qualitative value only
CRAN	shroud design for simulating hypersonic flow over the nose of a hemisphere shroud design for simulating hypersonic flow over the nose of a hemisphere following is an analytical method for designing a shroud which will generate the hypersonic pressure distribution on a hemisphere the method was found to be successful throughout the region of subsonic flow this shroud was designed as part of a low turbulence wind tunnel used for investigating the effects of cooling on boundary layer transition on a hemisphere the design of the shroud contour was carried out in two steps first an approximate solution for the incompressible irrotational flow field was found in the region and second the resulting contour was corrected for compressibility near the sonic region assuming one dimensional flow
CRAN	transition in the viscous wakes of blunt bodies at hypersonic speeds transition in the viscous wakes of blunt bodies at hypersonic speeds transition from laminar to turbulent flow in the hypersonic wakes of spheres was detected in laboratory measurements of the radiation from the flow field a hypervelocity gun facility was used to fire models 0 22 in in diameter into a range at velocities from 10 000 to 17 000 ft sec experiments were performed by changing a the material of the projectile b the ambient gas in the range and c the pressure in the range three optical techniques were used to observe the wake radiation which show a turbulent viscous wake as the pressure in the range is decreased from one atmosphere to about 20 cm hg which show the luminous flow field at pressures between 30 and ence of short luminous streaks which disappear suddenly as the pressure is decreased below 3 cm hg for air and below 0 8 cm hg for argon both air and argon which show the main features of the flow field above the transition pressure the intensity of radiation from the wake is always associated with fluctuations that appear to be the same phenomenon as the drum camera streaks the appearance of the streaks in the drum camera and photo multiplier data is interpreted as transition from laminar to turbulent flow in the viscous wake because experimental evidence shows that their appearance is not controlled by chemical radiative or ablative processes but depends on aerodynamic effects this conclusion is supported by other experiments based on optical and schlieren techniques the transition in the wake at positions very close to the body is given by a local reynolds number of 10 for air and 3 x 10 for argon the results indicate a possible local mach number effect
CRAN	stagnation point viscous hypersonic flow stagnation point viscous hypersonic flow several methods have been developed for computing the hypersonic low reynolds number flow in the stagnation region of a blunt body in general these methods involve complicated numerical solutions simultaneous iterations on several parameters are usually required in view of the boundary value nature of the problem the purpose of this note is to present an approximate closed form solution to axisymmetric stagnation point hypersonic flow in the viscous layer regime
CRAN	the conpressibility transformation and the turbulent boundary layer equations the conpressibility transformation and the turbulent boundary layer equations the compressibility transformation first introduced by dorod nitzyn has been applied in this paper to the equations of the turbulent boundary layer on a flat plate considering heat transfer and arbitrary prandtl numbers assuming the shear distribution to be invariant under the transformation the stream function and the momentum equation take the proper form for incompressible flow allowing the use of incompressible velocity profiles in the transformed coordinates application of croccos method to the transformed energy equation permits integration of the energy equation resulting in a formulism remarkably similar to that proposed by eckert finally the reference condition was chosen to correspond to the edge of the sublayer from considerations of the assumptions made regarding the shear stress distribution with this choice the reference enthalpy is in good agreement with eckerts formula over the ordinary range of test conditions in view of these results the analysis may be considered to provide a theoretical basis for the reference enthalpy method
CRAN	local heat transfer to a yawed infite circular cylinder in laminar compressible flow local heat transfer to a yawed infite circular cylinder in laminar compressible flow this note presents a simplification of a method for calculating the ratio of local to stagnation line heat transfer coefficients on a yawed infinite circular cylinder in laminar compressible flow a brief description of the method of ref 1 is presented followed by a discussion of the assumptions and mathematical procedure which lead to a considerable simplification
CRAN	use of local similarity concepts in hypersonic viscous interaction problems use of local similarity concepts in hypersonic viscous interaction problems the problem of predicting the characteristics of a hypersonic laminar boundary layer that interacts with the external flow field is approached using the tangent wedge formulation for the inviscid flow field and the method of similar solutions for the viscous flow it is shown that the concept of local similarity which allows the pressure gradient parameter to vary in the streamwise direction leads to an explicit relation between the viscous and inviscid flows for all values of the hypersonic interaction parameter the conditions of strong and limits of the general relations the present theory is compared with three independent experimental investigations in each case the agreement is found to be excellent over the range of investigated it is shown using asymptotic solutions to the exact boundary layer equations that the present theory is applicable to a wide variety of viscous interaction problems a large number of solutions to the laminar boundary layer similarity equations for a perfect gas with cross flow and surface mass transfer are given these numerical results when combined with the solutions of previous authors are sufficient to describe the range of conditions with high precision
CRAN	similitude of hypersonic flows over slender bodies in non equilibrium dissociated gases similitude of hypersonic flows over slender bodies in non equilibrium dissociated gases this paper is concerned with the similitude laws governing inviscid nonequilibrium gas flows around blunt or sharp nosed slender bodies at zero angle of attack based on the hypersonic small disturbance flow theory some related features of the interaction between the effects of nose bluntness and nonequilibrium dissociation and vibration and the influence of a dissociated freestream are also discussed the hypersonic equivalence principle and the related similitude for affinely related bodies are set forth for nonequilibrium flows in either diatomic gases or a gas mixture such as air for a family of diatomic gases as opposed to a given gas such as air a generalized ambient gas state scaling condition is obtained whereby the ambient density and temperature need not be simulated a detailed discussion is given of blunted cylinders and slabs or sharp nosed cones and wedges including example nonequilibrium flow field correlations of numerical solutions available in the literature low density nonequilibrium flows with a negligible shock layer atom recombination rate are also examined as expected a less restrictive small disturbance similitude law is obtained in this case
CRAN	biots variational principle in heat conduction biots variational principle in heat conduction biots variational principle is applied to a number of different one dimensional heat conduction problems these problems show the applicability of the variational principle to problems involving prescribed heat flux boundary conditions and to those with temperature dependent material properties a method is introduced for including boundary conditions when these are expressed as prescribed heat fluxes the idea behind this is overall energy balance within the body which is a constraint condition to be satisfied by the time histories of the generalized coordinates the variational principle is then applied to the well known problem of constant surface heat flux in order to present the technique and provide a basis for the remaining sections the equivalence of the result obtained in applying the variational principle for a prescribed surface temperature history to that obtained for a prescribed heat flux is also pointed out radiation cooling due to fourth power radiation from semi infinite solids and finite slabs together with radiation according to newtons law of cooling is then treated finally the introduction of temperature dependent material properties is discussed and the determination of the temperature distribution in a semi infinite solid with variable properties is investigated
CRAN	the stacking of compressor stage characteristics to give an overall compressor performance map the stacking of compressor stage characteristics to give an overall compressor performance map a method of calculation is developed to compute the overall performance of a multi stage axial compressor from a knowledge of the individual stage characteristics by a stacking technique compressor models are designed and their overall performance calculated these results are compared to show qualitatively the effect of alterations in design and stage performance on overall performance and to find how compressors should be designed for optimum performance
CRAN	a theoretical and experimental study of oscillating wedge shaped aerofoils in hypersonic flow a theoretical and experimental study of oscillating wedge shaped aerofoils in hypersonic flow aerodynamic stiffness and damping derivatives have been measured in a hypersonic gun wind tunnel for sharp and blunt nosed two dimensional single wedge shapes oscillating in the pitching mode in hypersonic flow the results which have been compared with theoretical prediction modified to account for leading edge bluntness show that this may increase the damping by up to 50 percent for certain axis positions details of the experimental technique designed to measure the derivatives in the short running times available are described
CRAN	calculation of sideslip derivatives and pressure distribution in asymmetric flight conditions on a slender wing fin configuration calculation of sideslip derivatives and pressure distribution in asymmetric flight conditions on a slender wing fin configuration the flow around slender wing fin configurations having curved leading edges whose shape is defined by polynomials is considered a general expression for the pressure distribution on such a configuration in asymmetric flow is derived and the derivatives due to the particular case of sideslipping motion are also given no numerical results are given for wing fin load distribution but the sideslip derivatives have been evaluated in a number of cases for gothic and ogee wings
CRAN	measurements of aerodynamic heating on a 15 cone of graded wall thickness at a mach number of 6 8 measurements of aerodynamic heating on a 15 cone of graded wall thickness at a mach number of 6 8 this note describes transient wall temperature measurements made on a in an airstream of mach number 6 8 the skin of the model was sufficiently thin to allow it to reach zero heat transfer conditions within a running time of one minute in order to reduce effects of longitudinal heat conduction during a run the electroformed nickel skin of the model was made with graded thickness and as a result fairly uniform temperature distributions along the surface were obtained at all times in both the laminar and turbulent regions values of heat transfer calculated from the wall temperature time histories using the thin wall temperature are compared to theoretical estimates using the intermediate enthalpy method 10 11
CRAN	boundary layer characteristics of caret wings boundary layer characteristics of caret wings the theory of laminar boundary layers along flat surfaces has been used in conjunction with eckerts approximations to the displacement thickness skin friction and temperature profiles on the undersurface of a caret wing configuration to a first approximation it has been assumed that parallel flow exits behind the shock outside the boundary layer and the displacement of the shock by the boundary layer near the leading edge is neglected conduction of heat within the body and along the surface is neglected but radiation is included so that are found examples are given for various altitudes and configurations and the effect of the skin friction on the lift drag ratio calculated assuming the undersurfaces to be plane
CRAN	the contraction of satellite orbits under the influence of air drag pt iv with scale height dependent on altitude the contraction of satellite orbits under the influence of air drag pt iv with scale height dependent on altitude the effect of air drag on satellite orbits of small eccentricity e was studied in part i tech note gw 533 on the assumption that atmospheric density varies exponentially with distance r from the earths centre so that the density scale height h defined as is constant in practice h varies with height in an approximately linear manner and in the present note the theory is developed for an atmosphere in which h varies linearly with r equations are derived which show how perigee distance and orbital period vary with eccentricity and how eccentricity varies with time expressions are also obtained for the life time and air density at perigee in terms of the rate of change of orbital period the results are also presented graphically the results are formulated in two ways the first is to specify the extra terms to be added to the constant h equations of part i the second the best constant value of h for use with the equations of part i for example it is found that the constant h equations connecting perigee distance or orbital period and eccentricity can be used unchanged without loss in accuracy if h is taken as the value of the variable h at a height above the mean perigee height during the time interval being considered where and decreases from to 0 as e decreases from 0 02 to 0 similarly the constant h equations for air density at perigee can still be used if h is evaluated at a height above perigee where and decreases to zero as e decreases from constant h equations can still be used if h is evaluated at the scale height below the initial height variation of h with altitude has a small effect on the lifetime   about 3   and on the e versus time curve
CRAN	experimental study of the velocity and temperature distribution in a high velocity vortex type flow experimental study of the velocity and temperature distribution in a high velocity vortex type flow the vortex tube represents a simple device in which a particular type of vortex motion may be studied in the laboratory in an attempt to obtain a better understanding of such flows such an investigation has been pursued in the heat transfer laboratory of the university of minnesota the present paper summarizes the major results of this vortex tube investigation
CRAN	laminar heat transfer in tubes under slip flow conditions laminar heat transfer in tubes under slip flow conditions the effects of low density phenomena on the fully developed heat transfer characteristics for laminar flow in tubes has been studied analytically consideration is given to the slip flow regime wherein the major rarefaction effects are manifested as velocity and temperature jumps at the tube wall the analysis is carried out for both uniform wall temperature and uniform wall heat flux in both cases the slip flow nusselt numbers are lower than those for continuum flow and decrease with increasing mean free path extension of the results is made to include the effects of shear work at the wall temperature jump modifications for a moving fluid and thermal creep
CRAN	analysis of a loaded cantilever plate by finite difference methods analysis of a loaded cantilever plate by finite difference methods the various difference patterns necessary for finite difference solution of rectangular plate problems with various boundary conditions and under various transverse loads are developed the solution of one particular problem on deuce is also described
CRAN	chemical kinetics of high temperature air chemical kinetics of high temperature air when a hypersonic object enters earths atmosphere a shock wave is formed in front of it and the air passing through this shock wave is heated to high temperatures the shock heated molecules equilibrate their translational and rotational degrees of freedom within a distance of a few mean free paths to achieve equilibrium it is necessary to excite vibration dissociate molecules produce new molecules and produce ions and electrons the problem is complex since all these phenomena occur simultaneously and because the reaction rates depend on the temperature density and composition which are changing during the relaxation toward equilibrium the experimental techniques used to investigate these reactions are briefly discussed along with the resulting rate expressions obtained by the various investigators a compilation of the rate expressions for these reactions representing the authors evaluation of all the available data is presented several pertinent problems which are not yet completely understood and which still require theoretical and experimental investigation are outlined computed concentration temperature and density time histories are shown for three different shock speeds in air the time rate of change of concentration for each chemical reaction is also shown and regimes of importance for the various processes are discussed
CRAN	ablation of glassy materials around blunt bodies of revolution ablation of glassy materials around blunt bodies of revolution the steady state equations of motion for a thin layer of an incompressible glassy material on the surface of an ablating and radiating blunt body are reduced to a first order ordinary differential equation which is integrated numerically this solution is coupled with the solution of the air boundary layer for both laminar and turbulent heat transfer with or without mass vaporization of the ablating material the distribution of the effective energy of ablation around the body is thus obtained for a cone cylinder with a hemispherical cap that re enters the atmosphere at hypersonic flight speeds and has quartz as the ablating material it is found that the ablation process from turbulent heating is more efficient than from the laminar case because of increased vaporization this solution of the equations of motion at the stagnation point has been verified by are wind tunnel experiments the present state of development of the are wind tunnel does not permit its use for experimental investigations of ablation around blunt bodies under turbulent heating
CRAN	generalized heat transfer formulas and graphs generalized heat transfer formulas and graphs utilizing the research results of previously reported investigations of the laminar turbulent and radiative heat transfer in dissociated air some generalized formulas for calculating heat transfer are given graphs for determining the laminar heat transfer momentum thickness reynolds number and turbulent heat transfer distributions around an axisymmetric body are also given these heat transfer correlations are valid for velocities between 6000 and 26 000 fps and for altitudes up to 250 000 ft this range of velocities and altitudes covers the important re entry regime of practical re entry trajectories having interest today in the last section of this report these generalized results are specialized for icbm nose cone re entry applications these formulas and graphs may be found useful for making rapid engineering estimates and preliminary design evaluations of the heating problems associated with re entry into earths atmosphere
CRAN	closing reply to comments on generalized heat transfer formulas and graphs for nose cone re entry into the atmosphere closing reply to comments on generalized heat transfer formulas and graphs for nose cone re entry into the atmosphere in a recent paper 1 detra and hidalgo have shown that when the boundary layer is turbulent the heat flux per unit area at the sonic point of a nose cone may exceed the corresponding laminar heat flux per unit area at the stagnation point the ratio of turbulent sonic point to laminar stagnation point heat flux per unit area has been estimated 2 to vary from about 1 0 to 10 for a hemispherical nose as the reynolds number based on nose diameter increases from 10 to 10 since for an axisymmetric body the surface area in the vicinity of the sonic point greatly exceeds the area in the vicinity of the stagnation point the ratio of turbulent to laminar heat fluxes to the entire body will be much greater than the above quoted ratios of heat fluxes per unit area
CRAN	numerical comparison between exact and approximate theories of hypersonic inviscid flow past slender blunt nosed bodies numerical comparison between exact and approximate theories of hypersonic inviscid flow past slender blunt nosed bodies this paper presents numerical results of exact calculations of the inviscid equilibrium flow about a long hemisphere cylinder in motion at hypersonic velocity a comparison is made with blast wave as well as free layer theories of hypersonic flow as a result of the comparison it is concluded that the second order blast wave theory can be used for the purpose of finding the shock shape and the body pressure distribution however this procedure is definitely empirical and cannot be justified on rational or theoretical grounds we show that the presently calculated radial distribution of energy is radically different than that given by blast wave theory if body shapes other than those considered here are of interest the only reliable approach at the present time is to carry out numerical calculations it was found that for certain flight velocities the pressure on the body does not decay to free stream pressure monotonically but overexpands
CRAN	a numerical comparison between exact and approximate theories of hypersonic inviscid flow past slender blunt nosed bodies a numerical comparison between exact and approximate theories of hypersonic inviscid flow past slender blunt nosed bodies this note refers to paper of same title by feldman in ars j 30 validity of blast wave theory cannot be justified on rational or theoretical grounds because of different values of energy in cross flow field as calculated by this theory and by method of characteristics present note questions this conclusion shows reasonably good agreement when energy is calculated for points where shock location streamline pattern and velocity temperature and pressure profiles are adequately defined and still better agreement when energy is calculated from flow quantities provided by  characteristics method results are checked using data from independent source conclusion is reached that blast wave theory is still valid
CRAN	experimental measurements of turbulent transition motion statistics and gross radial growth behind hypervelocity object experimental measurements of turbulent transition motion statistics and gross radial growth behind hypervelocity object the laminar turbulent transition behind 0 500 in  diameter spheres at 8500 ft sec and behind measured as a function of pressure schlieren motion picture techniques were used to analyze the turbulent motion and the results are described autocorrelation functions of the density fluctuations of the turbulence have been measured from these values has been calculated and the results are given for several positions in the turbulent trail at 30 mm hg downstream air pressure in addition the authors previous measurements of the gross radial growth of the turbulent wake have been extended to pressures of 10 mm hg for the case of 0 500 in  diameter spheres and to the trail behind
CRAN	heat transfer at the forward stagnation point of blunt bodies heat transfer at the forward stagnation point of blunt bodies relations are presented for the calculation of heat transfer at the forward stagnation point of both two dimensional and axially symmetric blunt bodies the relations for the heat transfer which were obtained from exact solutions to the equations of the laminar boundary layer are presented in terms of the local velocity gradient at the stagnation point these exact solutions include effects of variation of fluid properties prandtl number and transpiration cooling examples illustrating the calculation procedure are also included
CRAN	a theoretical study of the effect of upstream transpiration cooling on the heat transfer and skin friction characteristics of a compressible laminar boundary layer a theoretical study of the effect of upstream transpiration cooling on the heat transfer and skin friction characteristics of a compressible laminar boundary layer an analysis is presented which predicts the skin friction and heat transfer characteristics of a compressible laminar boundary layer on a solid flat plate preceded by a porous section that is transpiration cooled the analysis is restricted to a prandtl number of unity and linear variation of viscosity with temperature the local skin friction has been found to have a low value in the region of transpiration cooling and then to increase until it approaches the value for a completely nonporous surface asymptotically the initial increase in local skin friction is rapid as half of the ultimate increase occurs in a distance beyond the porous region that is about 20 percent of the length of the porous region for all rates of injection when the total coolant flow rate is kept constant and the porous length is varied it is found that the average skin friction on a partially porous plate is slightly lower than that on a fully porous plate the local heat transfer behaves in a manner similar to that of the local skin friction it is found in an example that the temperature at the end of a partially porous plate could be maintained at about the same temperature as a fully porous plate by doubling the total rate of coolant flow
CRAN	a geometric problem related to the optimum distribution of lift on a planar wing in supersonic flow a geometric problem related to the optimum distribution of lift on a planar wing in supersonic flow the problem studied may be regarded as a problem of geometry its simplest form loosely stated is then as follows a mountain rises up from the x y plane determine the exact shape of the mountain knowing only the cross sectional area of every possible cut which can be made through the mountain with a vertical plane in a more complicated version of the problem the given information might be restricted to the cross sectional area of every cut which can be made by a vertical plane inclined less than 45 to the y axis this latter case has direct applications to certain minimum drag problems in supersonic flow the shape of the mountain corresponds to the unknown shape of the optimum lift distribution on a planar wing the cross sectional area of a cut is the integrated value of the lift along a straight line crossing the wing plan form for a restricted range of line inclinations these optimum integrated lift values can sometimes be determined directly here it is assumed that they are given the problem in its simplest form was originally solved by radon who found solutions for a large class of such problems the derivation presented here may perhaps be more readily understood
CRAN	concerning the effect of compressibility on laminar boundary layers and their separation concerning the effect of compressibility on laminar boundary layers and their separation the theory of compressible flow in a laminar boundary layer has been developed for the case when the viscosity is assumed to be proportional to the absolute temperature and the prandtl number is unity these assumptions may be compared with the empirical relations suggested by cope it is shown that a transformation of the ordinate normal to the layer can lead to a simplified form of equation of motion very similar to the ordinary incompressible equation but modified by a multiplicative factor g in the pressure term this factor is greater than unity at the boundary and tends to one at the outside of the layer several particular solutions are considered including accelerated flow with a linearly increasing velocity and retarded flow along a flat plate with a linearly decreasing velocity the general implications of the theory are discussed and qualitative conclusions are drawn when the mainstream velocity starts from a stagnation point rises to a maximum and subsequently falls it is concluded that for such a velocity distribution increasing compressibility will reduce the skin friction increase the boundary layer thickness and cause earlier separation as compared with the incompressible flow with the same mainstream velocity distribution and the kinematic viscosity corresponding to conditions at the stagnation point
CRAN	the law of the wake in the turbulent boundary layer the law of the wake in the turbulent boundary layer after an extensive survey of mean velocity profile measurements in various two dimensional incompressible turbulent boundary layer flows it is proposed to represent the profile by a linear combination of two universal functions one is the well known law of the wall the other called the law of the wake is characterized by the profile at a point of separation or reattachment these functions are considered to be established empirically by a study of the mean velocity profile without reference to any hypothetical mechanism of turbulence using the resulting complete analytic representation for the mean velocity field the shearing stress field for several flows is computed from the boundary layer equations and compared with experimental data the development of a turbulent boundary layer is ultimately interpreted in terms of an equivalent wake profile which supposedly represents the large eddy structure and is a consequence of the constraint provided by inertia this equivalent wake profile is modified by the presence of a wall at which a further constraint is provided by viscosity the wall constraint although it penetrates the entire boundary layer is manifested chiefly in the sublayer flow and in the logarithmic profile near the wall finally it is suggested that yawed or three dimensional flows may be usefully represented by the same two universal functions considered as vector rather than scalar quantities if the wall component is defined to be in the direction of the surface shearing stress then the wake component at least in the few cases studied is found to be very nearly parallel to the gradient of the pressure
CRAN	local heat transfer and recovery temperature on a yawed cylinder at a mach number of 4 15 and high reynolds numbers local heat transfer and recovery temperature on a yawed cylinder at a mach number of 4 15 and high reynolds numbers local heat transfer equilibrium temperatures and wall static pressures have been measured on a circular cylinder at yaw angles of 0 10 20 40 and 60 the reynolds number range of the tests was from 1x10 to 4x10 based on cylinder diameter increasing the yaw angle from 0 to 40 increased the stagnation line heat transfer coefficients by 100 to 180 percent a further increase in yaw angle to heat transfer coefficients at zero yaw angle the boundary layer over the entire front half of the cylinder was laminar but at yaw angles of 40 and 60 it was evidently completely turbulent including the stagnation line as determined by comparison of local heat transfer coefficients with theoretical predictions the level of heating rates and the nature of the chordwise distribution of heat transfer indicated that a flow mechanism different from the conventional transitional boundary layer may have existed at the intermediate yaw angles of 10 and 20 at all yaw angles the peak heat transfer coefficient occurred at the stagnation line and the chordwise distribution of heat transfer coefficient decreased monotonically from this peak the average heat transfer coefficients over the front half of the cylinder are in agreement with previous data for a comparable reynolds number range the theoretical heat transfer distributions for both laminar and turbulent boundary layers are calculated directly from simple quadrature formulas derived in the present report
CRAN	similar solutions for the compressible boundary layer on a yawed cylinder with transpiration cooling similar solutions for the compressible boundary layer on a yawed cylinder with transpiration cooling heat transfer and skin friction parameters obtained from exact numerical solutions to the laminar compressible boundary layer equations for the infinite cylinder in yaw are presented the chordwise flow in the transformed plane is of the falkner skan type solutions are given for chordwise stagnation flow with both a porous and a nonporous wall the effect of a linear viscosity temperature relation is compared with the effect of the sutherland viscosity temperature relation at the stagnation line of the cylinder for a prandtl number of 0 7 the effects of pressure gradient mach number yaw angle and wall temperature are investigated for a linear viscosity temperature relation and a prandtl number of 1 0 with a nonporous wall the results indicate that compressibility effects become important at large mach numbers and yaw angles with larger percentage effects on the skin friction than on the heat transfer the use of the two different viscosity relations gives about the same results except when large changes in temperature occur across the boundary layer as for a highly cooled wall the present solutions predict that a larger amount of coolant would be required at a given large mach number and yaw angle than would be predicted from solutions of the corresponding incompressible boundary layer equations
CRAN	investigation of local heat transfer and pressure drag characteristics of a yawed circular cylinder at supersonic speeds investigation of local heat transfer and pressure drag characteristics of a yawed circular cylinder at supersonic speeds local heat transfer coefficients temperature recovery factors and pressure distributions were measured on a circular cylinder at a nominal mach number of 3 9 over a range of free stream reynolds numbers from from 0 to 44 it was found that yawing the cylinder reduced the local heat transfer coefficients the average heat transfer coefficients and the pressure drag coefficients over the front side of the cylinder for example at is reduced by 34 percent and the pressure drag by 60 percent the amount of reduction may be predicted by a theory presented herein local temperature recovery factors were also reduced by yaw but the amount of reduction is small compared to the reduction in heat transfer coefficients a comparison of these data with other data obtained under widely different conditions of body and stream temperature mach number and reynolds number indicates that these factors have little effect upon the dropoff of heat transfer due to yaw
CRAN	aerodynamic characteristics of a circular cylinder at mach number of 6 86 and angles of attack up to 90 aerodynamic characteristics of a circular cylinder at mach number of 6 86 and angles of attack up to 90 pressure distribution and force tests of a circular cylinder have been made in the langley 11 inch hypersonic tunnel at a mach number of based on diameter and angles of attack up to 90 the results are compared with the hypersonic approximation of grimminger williams and young and with a simple modification of the newtonian flow theory the comparison of experimental results shows that either theory gives adequate general aerodynamic characteristics but that the modified newtonian theory gives a more accurate prediction of the pressure distribution the calculated crossflow drag coefficients plotted as a function of crossflow mach number were found to be in reasonable agreement with similar results obtained from other investigations at lower supersonic mach numbers comparison of the results of this investigation with data obtained at a lower mach number indicates that the drag coefficient of a cylinder normal to the flow is relatively constant for mach numbers above about 4
CRAN	shock wave effects on the laminar skin friction of an insulated flat plate at hypersonic speeds shock wave effects on the laminar skin friction of an insulated flat plate at hypersonic speeds an approximate theory on the phenomena of interaction between the shock wave and the laminar boundary layer on an insulated flat plate at hypersonic speeds has been formulated results on the rate of growth of the boundary layer thickness and the rate of decay of the shock wave strength have been found that hold for a new set of formulas for the average skin friction coefficient over an insulated flat plate at hypersonic speeds has been obtained calculations on the basis of the new formulas yield the data shown in figs steady decrease in as increases the present results indicate that may increase with at hypersonic mach numbers
CRAN	an experimental investigation of leading edge shock wave boundary layer interaction at mach 5 8 an experimental investigation of leading edge shock wave boundary layer interaction at mach 5 8 the boundary layer on a slender body tends to be very thick at hypersonic speeds it interacts with the external flow by producing larger flow deflections near the leading edge than those due to the body alone flow around the boundary layer gives rise to an induced pressure with a negative gradient which thins the boundary layer and increases the skin friction with respect to the zero pressure gradient value experiments on a flat plate with a sharp leading edge have been performed in the galcit 5 dash by 5 dash in mach 5 8 hypersonic wind tunnel the induced pressure was measured by means of orifices in the plate surface profiles of mach number velocity mass flow pressure and momentum deficiency were calculated from impact pressure surveys normal to the plate surface made at various distances from the leading edge the results are as follows 1 the induced pressures are 25 per cent higher than the weak interaction theory 2 the boundary layer and the external flow are distinctly separate for as low as 6 000 3 the shock wave location is in good agreement with that predicted by the friedrichs theory for a body shape equivalent to the observed boundary layer displacement thickness 4 expansion waves reflected from the shock are weak 5 the average skin friction coefficient tends toward and nearly matches the zero pressure gradient value downstream but increases to approximately twice that value as the leading edge is approached
CRAN	on the boundary layer equations in hypersonic flow and their approximate solutions on the boundary layer equations in hypersonic flow and their approximate solutions analytical solutions of the prandtl boundary layer equations are obtained for the problem of the strong interaction between the leading edge shock and the viscous layer over a flat plate at hypersonic velocities as the mach number increases and the interaction region spreads downstream over the plate the local skin friction coefficient increases rapidly over its conventional value the local heat transfer coefficient at first remains practically unaffected but then also begins to increase with mach number
CRAN	heat transfer to flat plate in high temperature rarefied ultra high mach number flow heat transfer to flat plate in high temperature rarefied ultra high mach number flow an investigation was conducted in a hypersonic shock tunnel to determine the local heat transfer rates for a sharp leading edge flat plate the free stream mach number range was 7 95 to 25 1 with stagnation temperatures of approximately 2550 and 6500 r for these temperature and mach number conditions the strong interaction parameter varied from 2 35 to 826 the corresponding knudsen numbers based on the ratio of the free stream mean free path and the leading edge thickness varied from 0 38 to 85 5 for free stream mach numbers greater than 10 knudsen numbers of approximately unity and perfect gas conditions the calculated heat transfer coefficients were found to vary as as predicted by the noninsulated flat plate theory of li and nagamatsu for the case of the leading edge slip phenomenon drastically reduced the local heat transfer coefficients as compared to the theoretical values predicted with no slip at the surface for the extreme case of and the measured local heat transfer rate was an order of magnitude less than the analytical value both the knudsen number and the free stream mach number are important physical parameters that determine the extent of the slip flow region
CRAN	boundary layer displacement and leading edge bluntness effects in high temperature hypersonic flow boundary layer displacement and leading edge bluntness effects in high temperature hypersonic flow two important features of hypersonic flow over slender or thin bodies are the displacement effect of the boundary layer and the large down stream influence of leading edge bluntness the present paper contributes new theoretical and experimental results on this problem the interaction of the two effects is treated theoretically by extending the basic shock layer concept in the outer inviscid flow a model consisting of a detached shock layer and an entropy layer is introduced to account for bluntness in the boundary layer the approximate solution is found to be governed by a local flat plate similarity under the assumption of a strong bow shock and a specific heat ratio close to unity a theory is developed for an arbitrary thin body for flat plate afterbodies the theory yields a solution agreeing with blast wave theory at one limit and strong interaction theory at the other within the framework of the present theory the problems involving angle of attack are also analyzed complementary to the above study a hypersonic similitude involving strong shocks but not requiring close to one a natural comparison with experimental data correlated on the basis of this similitude flat plate experiments in air conducted in the c a l 11 x 15 dashin hypersonic shock tunnel under cold wall conditions included measurement of surface heat transfer distributions and schlieren studies for zero and nonzero angle of attack steady laminar heat transfer rates were measured by means of thin film resistance thermometers at air test flow mach numbers around 12 free stream reynolds numbers from 1 4 x 10 to 1 for most of the experiments airflow stagnation temperatures ranged from ratios of about 0 15 the range of test conditions at this stagnation temperature encompassed the limiting cases of dominant bluntness and dominant viscous interaction effects heat transfer distributions were also measured on a sharp plate for air stagnation temperatures ranging from 2 000degreek up to 4 000degreek the experimental data are quite well correlated in terms of the foregoing theoretical similitude variables characterizing combined effects of boundary layer displacement and bluntness the correlations obtained suggest that for the present experimental conditions at least the hypersonic viscous similitude is valid even with leading edge bluntness in the paper is generally fair
CRAN	viscous hypersonic similitude viscous hypersonic similitude an extension of classical hypersonic similitude is developed which takes into account the interaction effect of the displacement thickness of the boundary layer a basic result of this viscous similitude is that the total drag including frictional drag obeys the classical similarity law for the pressure drag additional similarity conditions governing viscous effects must be imposed in this similitude underlying the similitude is a new hypersonic boundary layer independence principle according to this principle the principal part of a hypersonic boundary layer with given pressure and wall temperature distributions and free stream total enthalpy is independent of the high external mach number distribution outside the boundary layer various features of viscous hypersonic similitudes are discussed it is found for example that it applies to three  dimensional boundary layer interaction effects on flat bodies provided the concepts of strip theory may be applied and provided the aspect ratio is an invariant
CRAN	inviscid flow with nonequilibrium molecular dissociation for pressure distributions encountered in hypersonic flight inviscid flow with nonequilibrium molecular dissociation for pressure distributions encountered in hypersonic flight one dimensional inviscid nonequilibrium flows of a two component model gas are studied for prescribed pressure variations and an average reaction rate based on recent data for oxygen recombination these flows are interpreted in relation to the flow along streamlines around blunt hypersonic bodies assuming equilibrium conditions in the subsonic region it is estimated that the flow in the initial supersonic expansion region which is approximately of prandtl meyer character will be chemically frozen with respect to the molecular dissociation of the primary components under the hypersonic high altitude flight conditions considered the flight conditions consist of flight velocities between furthermore on bodies of small surface inclination beyond the nose the flow will continue to be effectively frozen for at least 20 ft down stream of the nose these conclusions may lead to the simplification of procedures for theoretical calculation and testing the problem of distinguishing a dimensionless length reaction rate parameter which characterizes the extent of departures from equilibrium or from frozen behavior in the flow fields of interest here is discussed
CRAN	atomic recombination in a hypersonic wind tunnel nozzle atomic recombination in a hypersonic wind tunnel nozzle the flow of an ideal dissociating gas through a nearly conical nozzle is considered the equations of one dimensional motion are solved numerically assuming a simple rate equation together with a number of different values for the rate constant these calculations suggest that deviations from chemical equilibrium will occur in the nozzle if the rate constant lies within a very wide range of values and that once such a deviation has begun the gas will very rapidly freeze the dissociation fraction will then remain almost constant if the flow is expanded further or even if it passes through a constant area section an approximate method of solution making use of this property of sudden freezing of the flow has been developed and applied to the problem of estimating the deviations from equilibrium under a wide range of conditions if all the assumptions made in this paper are accepted then lack of chemical equilibrium may be expected in the working sections of hypersonic wind tunnels and shock tubes the shape of an optimum nozzle is derived in order to minimize this departure from equilibrium it is shown that while the test section conditions are greatly affected by freezing the flow behind a normal shock wave is only changed slightly the heat transfer rate and drag of a blunt body are estimated to be reduced by only about 25 per cent even if complete freezing occurs however the shock wave shape is shown to be rather more sensitive to departures from equilibrium
CRAN	viscous and inviscid stagnation flow in a dissociated hypervelocity free stream viscous and inviscid stagnation flow in a dissociated hypervelocity free stream high reynolds number hypersonic stagnation flow over a blunt nosed body in a nonequilibrium dissociated free stream is analyzed and compared to a similar flow in an initially undissociated ambient gas free stream dissociation effects on various equilibrium stagnation flow properties in air are presented as a function of the ambient atom mass fraction and dissociation energy for velocities ranging from 15 000 to 25 000 fps significant changes in the bow shock geometry stagnation gas state and boundary layer behavior are found when the free stream dissociation involves more than 10 of the total energy it is observed that for large amounts of both atomic oxygen and nitrogen ahead of the body the equilibrium shock layer properties converge toward those pertaining to chemically and vibrationally frozen flow across the bow shock moreover under certain conditions the ionization level can be increased by an order of magnitude and the usual reduction in frozen boundary layer heat transfer due to a highly cooled noncatalytic surface can increase from stall of adjacent stages the effects of compromises of stage matching to favor part speed operation were also considered this phase of the study indicated that such compromises would severely reduce the complete compressor stall margin furthermore the low speed stage stall problem is transferred from the inlet stages to the middle stages which are more susceptible to abrupt stall characteristics the analysis indicates that inlet stages having continuous performance characteristics at their stall points are desirable with respect to part speed compressor performance these characteristics must however be obtained when the stages are operating in the flow environment of the multistage compressor alleviation of part speed operational problems may also be obtained by improvement in either stage flow range or stage loading margin the results of this analysis are only qualitative the trends obtained however are in agreement with those obtained from experimental studies of high pressure ratio multistage axial flow compressors and the results are valuable in developing an understanding of the off design problem in addition to these stage matching studies a general discussion of variable geometry features such as air bleed and adjustable gas model numerical solutions of non equilibrium airflows with fully coupled chemistry provide a preliminary verification of such scaling for benser w a limit characteristics the analysis indicated that all these problems could be attributed to discontinuities in the performance characteristics of the front stages such discontinuities can be due to the type of stage stall or to a deterioration of stage performance resulting blades is included
CRAN	on hypersonic similitude on hypersonic similitude tsien in a recent paper j math phys mass inst tech sonic flows around slender bodies and has pointed out that the product of mach number and fineness ratio is a basic similarity parameter the author enlarges on this notion indicating that the problem of hypersonic flow about a slender body in three dimensions is the same as that of a certain two dimensional nonsteady flow with time replacing the lengthwise spatial coordinate characterized by essentially the same similarity parameter
CRAN	dissociation scaling for nonequilibrium blunt nose flows dissociation scaling for nonequilibrium blunt nose flows stage stacking study the principal problems considered were poor low speed efficiency multiple valued performance characteristics at intermediate speeds and poor intermediate speed compressor surge or stall naca rm e56b03b 1956 chapter xiii compressor operation with one or more blade rows stalled an analysis of the part speed operating problems of high pressure ratio air
CRAN	further developments of new methods in heat flow analysis further developments of new methods in heat flow analysis lagrangian methods in heat flow problems and transport phenomena were introduced by the writer in some previous work the present paper develops further one particular aspect of the method   i e the elimination of ignorable coordinates this is accomplished by a special choice of generalized coordinates each of which is constituted by an arbitrary temperature distribution and an associated flow field the latter is a vector field which is derived from the corresponding scalar field by a variational method the procedure is valid for a certain class of nonlinear problems provided we replace the temperature by the heat content as the unknown it is shown that for normal coordinates derivation of the associated flow field is immediate the use of normal coordinates and their associated flow fields is illustrated by an example introduction of dirac functions and associated flow fields yields a procedure which constitutes a generalization of the classical formulation by greens functions and integral equations this is illustrated by application to one dimensional problems of heating of a homogeneous or composite slab and directly verified by classical methods in the appendix
CRAN	new thermo mechanical reciprocity relations with application to thermal stress analysis new thermo mechanical reciprocity relations with application to thermal stress analysis based on the variational formulation of linear thermodynamics as developed previously by the writer thermomechanical reciprocity relations are discussed which lead to new methods of analysis of thermal stresses these reciprocity relations are quite different from the usual ones derived from the analogy of thermal loading with a combination of surface and body force distribution the results are applicable to stationary and transient temperatures in elastic and viscoelastic structures the methods are entirely variational and do not require the evaluation of the temperature field the stresses at one point are expressed directly in terms of any arbitrary distribution temperatures applied externally including the effect of surface heat transfer layer the concepts and procedures are illustrated on a simple example the relation is pointed out between the reciprocity property and the generalization of castiglianos principle to thermomechanics
CRAN	approximate formulas for thermal stress analysis approximate formulas for thermal stress analysis the basis of any thermal stress analysis is the determination of the temperature distributions in the structure for arbitrary flight histories the determination of such distributions is rather tedious and not completely general this latter fact handicaps optimization studies in the project design stage when it is desirable to be able to express the thermal stress distributions in a general manner in this note general expressions are derived for the thermal stress distributions in a typical i section using similar assumptions to those of biot
CRAN	the melting of finite slabs the melting of finite slabs an approximate method known as the heat balance integral is used to determine the melting rate of a finite slab which is initially at a uniform temperature below the melting point the slab is acted upon by a constant heat input at one face and has its other face either insulated or kept at its initial temperature the first three terms of series solutions in an intrinsically small parameter are obtained for the time histories of melting and the temperature distribution in the slab
CRAN	influence coefficients for real gases influence coefficients for real gases in the analysis of one dimensional fluid flow problems it is often assumed that the behavior of the medium is that of a perfect gas this assumption is justified provided the pressure and temperature range of interest is small and near atmospheric at higher pressures and temperatures various deviations are introduced thereby causing deviations from the results obtained by using the ideal fluid flow equations in this note influence coefficients similar to those developed by shapiro are presented for the case of real gases this analysis is based upon the use of various functions of the compressibility factor emmons some of the assumptions made were as follows 1 the flow is one dimensional and steady 2 changes in the stream properties are continuous and 3 the flow is comprised of imperfect gases
CRAN	conduction of heat in a solid with a power law of heat transfer at its surface conduction of heat in a solid with a power law of heat transfer at its surface the nonlinear boundary value problem where and m are constants is solved formally by first introducing power series in t for the unknown temperature and flux at the surface and then determining the coefficients in those series in this manner the temperature function is determined as a series of repeated integrals of error functions the convergence is rapid only for small values of t the special cases and generalizations of the condition at the surface for which the same method applies are noted surface temperatures are also found by methods of difference equations where t is not limited to small values graphs of these temperatures corresponding to various laws of heat transfer at the surface are shown
CRAN	nonlinear heat transfer problem nonlinear heat transfer problem a study has been made of the time dependent heat conduction in a semi infinite medium subject to a boundary condition which can involve the temperature in a nonlinear manner a formulation for the determination of the surface temperature which is often of greatest physical interest leads to a nonlinear volterra integral equation a simple iterative solution method with an accuracy suitable for many practical purposes is presented as an example the problem of the time dependent surface temperature of a body receiving heat according to the stefan boltzmann law is treated the analysis is also applicable to physical adsorption or chemisorption processes which occur at the boundary
CRAN	an approximate treatment of unsteady heat conduction in semi infinite solids with variable thermal properties an approximate treatment of unsteady heat conduction in semi infinite solids with variable thermal properties this very short paper presents an approximate procedure for the calculation of unsteady heat conduction in semi infinite solids with variable thermal properties it is claimed to be an improvement over previous efforts in this area since it yields physically sensible results for cases where thermal properties have a large dependence on temperature instead of using polynomials to represent an unsteady temperature profile an exponential form is used good agreement is shown for several cases where the method of the paper is compared with exact solutions
CRAN	variational analysis of ablation variational analysis of ablation the variational and lagrangian thermodynamics developed in earlier publications are directly applicable to problems of heat conduction with melting boundaries these techniques are used here in treating the problem of a half space subjected to a constant rate of heat input at the melting surface fig 1 the applicability of the lagrangian equations to this case follows from the fact that the basic variational principle is valid whether the boundaries are fixed or move as arbitrary functions of time this can be seen if we remember that the equations govern only the instantaneous configuration of the flow rates for a given geometry and temperature field
CRAN	compressor operation with one or more blade rows stalled compressor operation with one or more blade rows stalled an analysis of the part speed operating problems of high pressure ratio ratio multistage axial flow compressors was made by means of a simplified stage stacking study the principal problems considered were poor low speed efficiency multiple valued performance characteristics at intermediate speeds and poor intermediate speed compressor surge or stall limit characteristics the analysis indicated that all these problems could be attributed to discontinuities in the performance characteristics of the front stages such discontinuities can be due to the type of stage stall or to a deterioration of stage performance resulting from stall of adjacent stages the effects of compromises of stage matching to favor part speed operation were also considered this phase of the study indicated that such compromises would severly reduce the complete compressor stall margin furthermore the low speed stage stall problem is transferred from the inlet stages to the middle stages which are more susceptible to abrupt stall characteristics the analysis indicates that inlet stages having continuous performance characteristics at their stall points are desirable with respect to part speed compressor performance these characteristics must however be obtained when the stages are operating in the flow environment of the multistage compressor alleviation of part speed operation problems may also be obtained by improvement in either stage flow range or stage  loading margin the results of this analysis are only qualitative the trends obtained however are in agreement with those obtained from experimental studies of high pressure ratio multistage axial flow compressors and the results are valuable in developing an understanding of the off design problem in addition to these stage matching studies a general discussion of variable geometry features such as air bleed and adjustable blades is included
CRAN	some stall and surge phenomena in axial flow compressors some stall and surge phenomena in axial flow compressors observations of rotating stall have shown that a wide variety of stall patterns is possible hot wire anemometer data on a multistage compressor have shown a progressive type stall at low speeds the amplitude of the flow fluctuations increases in magnitude through the first few stages and then diminishes rapidly to a small value in the latter stages a stage stacking analysis has shown that rotating stall will exist over a large portion of the compressor map at low speeds but will be instigated almost simultaneously with compressor surge at high speeds blades failures attributable to resonant vibrations excited by rotating stall have been experienced in single and multistage compressors in the stage stacking analysis no deterioration of stage performance due to unsteady flow resulting from stall of adjacent stages was considered in general the pressure drop at the stall point is believed to be much larger than indicated by an analytical formulation of compressor performance compressor surge is attributed to a limit cycle operation about the compressor stall point and as indicated in a few compressor tests and in jet engine tests a small compressor discharge receiver volume may result simply in stall of the compressor without the cyclic characteristics of compressor surge in this event engine operation will be limited because of the large drop in performance which accompanies compressor stall
CRAN	effects of stage characteristics and matching on axial flow compressor performance effects of stage characteristics and matching on axial flow compressor performance the use of stage characteristics obtained from test data in the performance analysis and development of an axial flow compressor is described relative stage matching as shown by an idealized example and also by test experience factors governing major performance parameters are discussed and certain development problems and possible solutions are reviewed
CRAN	an approximate equation for the choke line of a compressor an approximate equation for the choke line of a compressor discussion of a similarity between the pressure ratio versus inlet mass flow coefficient characteristic of a stream or gas turbine and the analogous characteristic of an expansion laval nozzle this idea is extended to a compressor and a compression nozzle and an approximate expression for the choke line of the compressor is developed
CRAN	design of axial compressors design of axial compressors the main types of axial compressors are described and the use of generalized design curves to make performance estimates is advocated the different variables are weight power pressure ratio temperature rise mass flow rotational speed stage efficiency blade bending stresses due to aerodynamic loading and methods and materials of construction air outlets flow coefficients and different blade forms are also considered
CRAN	theoretical considerations of flutter at high mach number theoretical considerations of flutter at high mach number some of the theories for two dimensional oscillatory air forces which may be applied in flutter calculations at high mach numbers are discussed these include linear theory van dykes second order theory piston theory landahls method tangent wedge and tangent cone approximations newtonian theory and a new nonlinear pressure method a comparison of the theories is made by showing the results of flutter calculations for mach numbers up to 10 and the possibility of flutter at these higher mach numbers is pointed out results of flutter calculations are shown to illustrate the various effects arising from a nonlinear thickness theory the possibility of large flutter speed thickness effects which depend on frequency ratio is shown the influence of airfoil shape is discussed and flutter speed trends with center of gravity and elastic axis locations are presented some possible refinements of piston theory are discussed for use at very high mach numbers these include the use of local flow conditions and the use of newtonian theory over the leading edge of a blunt nosed airfoil
CRAN	wind tunnel techniques for the measurements of oscillatory derivatives wind tunnel techniques for the measurements of oscillatory derivatives this paper discusses the basic principles employed in techniques for the measurement of oscillatory derivatives in wind tunnels and gives some account of the associated instrumentation the suitability of the various techniques for different test conditions is also discussed and brief reference is made to wind tunnel effects on the measurements
CRAN	the equilibrium piston technique for gun tunnel operation the equilibrium piston technique for gun tunnel operation a modified technique for the operation of a gun tunnel is suggested based on experimental results if the piston mass and the initial barrel pressure are chosen correctly then the peak pressures associated with the gun tunnel may be eliminated under these conditions the piston is brought to rest with no overswing some measurements of the piston motion using a microwave technique are reported which confirm this idea the wave diagram associated with this mode of operation is shown and some calculations of the stagnation pressure are given which show that during the suggested running time the stagnation pressure may be considerably greater than the driving pressure if the driving chamber cross sectional area is large compared with that of the driven section for a uniform shock tube the stagnation pressure will always be less than the driving pressure the use of air helium and hydrogen as driving gases has been considered experiments in a gun tunnel are reported which show that the equilibrium piston technique enables steady stagnation pressures to be achieved over a time of approximately 15 ms using air as the driving gas the expansion caused by the piston acceleration is shown to interact with the stationary piston but this is found to produce only a small drop in stagnation pressure
CRAN	the properties of crossed flexure pivots and the influence of the point at which the strips cross the properties of crossed flexure pivots and the influence of the point at which the strips cross it is shown that the rotational stiffness of a crossed flexure pivot varies considerably when subjected to an applied force the type of variation can be radically changed simply by moving the point at which the strips cross the relation between torque and rotation for a given applied force is not exactly linear and the extent of the non linearity is determined by taking into account the small movements of the centre of rotation of the pivot finally for design purposes an analysis of the maximum stresses in the strips is given
CRAN	measurements of pitching moment derivatives for blunt nose aerofoils oscillating in two dimensional supersonic flow measurements of pitching moment derivatives for blunt nose aerofoils oscillating in two dimensional supersonic flow direct pitching moment derivatives have been measured using the method of scruton woodgate et al for two single wedge blunt nosed aerofoils these measurements were made at mach numbers of 1 75 and 2 47 and frequency parameters less than 0 02 in general nose blunting was found to have little effect on the derivatives although changes were observed for the thinner wedge at a mach number of 1 75
CRAN	new test techniques for a hypervelocity wind tunnel new test techniques for a hypervelocity wind tunnel the measurement of rocket exhaust effects on vehicle stability and the measurement of aerodynamic damping were made in an arc discharge type of hypervelocity wind tunnel sample data are given to indicate the quality of data obtainable in this tunnel and samples of self luminous and shadowgraph photographs are also presented
CRAN	aerodynamic forces moments and stability derivatives for slender bodies of general cross section aerodynamic forces moments and stability derivatives for slender bodies of general cross section the problem of determining the total forces moments and stability derivatives for a slender body performing slow maneuvers in a compressible fluid is treated within the assumptions of slender body theory general expressions for the total forces except drag and moments are developed in terms of the geometry and motions of the airplane and formulas for the stability derivatives are derived in terms of the mapping functions of the cross sections all components of the motion are treated simultaneously and second derivatives as well as first are obtained with respect to both the motion components and their time rates of change coupling of the longitudinal and lateral motions is thus automatically included a number of general relationships among the various stability derivatives are found which are independent of the configuration so that at most only 35 of a total of 325 first and second derivatives need be calculated directly calculations of stability derivatives are carried out for two triangular wings with camber and thickness one with a blunt trailing edge and for two wing body combinations one having a plane wing and vertical fin the influence on the stability derivatives of the squared terms in the pressure relation is demonstrated and the apparent mass concept as applied to slender body theory is discussed at some length in the light of the present analysis it is shown that the stability derivatives can be calculated by apparent mass although the general expressions for the total forces and moments involve additional terms
CRAN	the calculation of lateral stability derivatives of slender wings at incidence including fin effectiveness and correlation with experiment the calculation of lateral stability derivatives of slender wings at incidence including fin effectiveness and correlation with experiment comparisons are made between low speed experimental results and estimates based on attached flow theory for the lateral stability derivatives of slender wings at incidence and it is found that the flow separation has little effect on the sideslip derivatives the reduction in due to part span anhedral is evaluated and a semi empirical formula is derived to account for important second order terms for the rotary derivatives an attempt is made to estimate the effect of the leading edge vortices but no satisfactory conclusions have been reached the fin contributions to the derivatives are evaluated on the basis of treating the wing surface as a total reflection plate good agreement with experiment is reached for the sideslip derivatives and for the damping in yaw at moderate incidences sidewash is found to have a large effect on the rolling derivatives and further information on the strength and position of the leading edge vortices in non symmetric flow is required before a complete calculation of the sidewash can be given
CRAN	calculation of the flow past slender delta wings with leading edge separation calculation of the flow past slender delta wings with leading edge separation the flow past a slender delta wing with a sharp leading edge at incidence usually separates along this edge i e a vortex layer extends from the edge and rolls up to form a core a region of high vorticity a potential flow model of this is constructed in which the layer is replaced by a vortex sheet which is rolled up into a spiral in the region of the core this problem is reduced to a two dimensional one by assuming a conical field and using slender wing theory the shape and strength of the sheet are determined by the two conditions that it is a stream surface and sustains no pressure difference use is made of results previously obtained for the core region and the remaining finite part of the sheet is dealt with by choosing certain functions for its shape and strength the parameters in these functions are found by satisfying the two conditions stated above at isolated points results are obtained for the pressure distribution chord loading and norman force coefficient as functions of the ratio of the incidence to the apex angle the lift for a given incidence is about 15 below that found by brown and michael flow patterns are indicated in two typical cases the effect of separation on the drag due to lift of a wing with small thickness is discussed
CRAN	the 7 x 7 in hypersonic wind tunnel at rae farnborough part 1 design instrumentation and flow visualization techniques the 7 x 7 in hypersonic wind tunnel at rae farnborough part 1 design instrumentation and flow visualization techniques this is the first of three parts of the calibration report on the r a e some details of the design and lay out of the plant are given together with the calculated performance figures and the major components of the facility are briefly described the instrumentation provided for the wind tunnel is described in some detail including the optical and other methods of flow visualization used in the tunnel later parts will describe the calibration of the flow in the working section including temperature measurements a discussion of the heater performance will also be included as well as the results of tests to determine starting and running pressure ratios blockage effects model starting loads and humidity of the air flow
CRAN	the 7 in x 7 in hypersonic wind tunnel at r a e farnborough part ii heater performance the 7 in x 7 in hypersonic wind tunnel at r a e farnborough part ii heater performance tests on the storage heater which is cylindrical in form and mounted horizontally show that its performance is adequate for operation at m 6 8 and probably adequate for flows at m 8 2 with the existing nozzles in its present state the maximum design temperature of 680 degrees centigrade for operation at m 9 cannot be realised in the tunnel because of heat loss to the outlet attachments of the heater and quick acting valve which form in effect a large heat sink because of this heat loss there is rather poor response of stagnation temperature in the working section at the start of a run it is hoped to cure this by preheating the heater outlet cone and the quick acting valve at pressures greater than about 100 p s i g free convection through the fibrous thermal insulation surrounding the heated core causes the top of the heater shell to become somewhat hotter than the bottom which results in hogging distortion of the shell this free convection cools the heater core and a vertical temperature gradient is set up across it after only a few minutes at high pressure modifications to be incorporated in the heater to improve its performance are described
CRAN	the 7 in x 7 in hypersonic wind tunnel at r a e farnborough part iii   calibration of the flow in the working section the 7 in x 7 in hypersonic wind tunnel at r a e farnborough part iii   calibration of the flow in the working section the fused silica nozzle to give m 7 in the 7 in x 7 in hypersonic wind tunnel produces a flow field with an average mach number of 6 85 along the centreline of the working section the mach number gradually decreases towards the boundary layer and over a core of approximately mach number the nozzle heats up during a run but this has little effect on the mach number distribution at one station the mach number was one third per cent greater for a run of 1 minute than for a run of 10 seconds the temperature field in the inviscid flow has an average variation of in temperature with time throughout a run
CRAN	pressure measurements on a cone cylinder flare configuration at small incidences for m 6 8 pressure measurements on a cone cylinder flare configuration at small incidences for m 6 8 pressure measurements were made on a slender cone cylinder flare configuration slightly blunted at the nose for 0 3 and 6 degrees incidence at a free stream mach number of 6 8 it was found that the surface pressures obtained on the cone agreed with extrapolations to m equals 6 8 of theoretical values given in m i t tables kopal for yawed cones and that impact theory gave a good indication of the pressure level to be expected on all parts of the body where surface incidence was sufficiently large to merit its use the semi angles of the conical and flared parts of the model were both the pressure level on the flare rose in all cases to approximately that developed upstream on the cone surface no evidence of a marked over expansion to pressures below the free stream value was noticed at the junction between cone and cylinder
CRAN	formulae and approximations for aerodynamic heating rates in high speed flight formulae and approximations for aerodynamic heating rates in high speed flight this note gives formulae and approximations suitable for making preliminary estimates of aerodynamic heating rates in high speed flight the formulae are based on the intermediate enthalpy approximation which has given good agreement with theoretical and experimental evidence in the general flight case they could be used in conjunction with an analogue computer or a step by step method of integration to predict the variations of heat flow and skin temperature with time in the restricted case of flight at constant altitude and mach number simple analytical methods and results are given which include the effects of radiation and can be applied to thick as well as thin skins where h is the aerodynamic heat transfer factor and g d and k are the heat capacity thickness and thermal conductivity of the skin if 0 1 the skin is approximately thin i e temperature gradients across its thickness may be neglected
CRAN	duct flow in magnetohydrodynamics duct flow in magnetohydrodynamics this paper is an extension of the work of hartmann 2 and shercliff transverse magnetic fields    the simplest class of magnetohydrodynamic problems we are concerned here mainly with the boundary value problems associated with flow in ducts with conducting walls
CRAN	aerodynamic noise in supersonic wind tunnels aerodynamic noise in supersonic wind tunnels hot wire measurements in the free stream of a supersonic wind tunnel were made in the mach number range of 1 6 to 5 0 it is shown that the mass flow fluctuations increase very rapidly with increasing mach number if the fluctuation field is assumed to consist of sound waves dash an assumption that is consistent with the measurements dashthe sound intensity is approximately proportional to m within the range of the experiments furthermore the orientation of the field is found to be different from the mach line direction it corresponds to a sound source velocity of approximately one half the free stream velocity for the higher mach numbers it is shown that the turbulent boundary layer along the nozzle and the tunnel walls is responsible for this sound field
CRAN	on three dimensional bodies of delta planform which can support plane attached shock waves on three dimensional bodies of delta planform which can support plane attached shock waves this note collects together in one report available theoretical work on bodies which can support attached plane shock waves discusses some of the possible merits of such shapes and includes some calculations illustrating their properties also some preliminary results from wind tunnel tests are given together with details of proposed future tests
CRAN	corner interference effects corner interference effects the three dimensional incompressible flow of fluid along the corner of two semi infinite plates intersecting at right angles especially the interference of the boundary layers of the two plates is discussed mainly the more important case of turbulent boundary layer is treated by means of experimental studies carried out at the technical university of braunschweig some theoretical results for laminar flow are also taken into account in order to describe the interference effects in the boundary layer an interference displacement thickness and an interference skin friction have been introduced it is shown from experiments and also from theoretical considerations how these two quantities depend on reynolds number furthermore the influence of interference on the transition from laminar to turbulent flow is investigated in addition some preliminary results are given about the effect of the pressure gradient on the interference effects
CRAN	an approximate solution of the compressible laminar boundary layer on a flat plate an approximate solution of the compressible laminar boundary layer on a flat plate following a major assumption that enthalpy and velocity are dependent only on local conditions an enthalpy velocity relation is obtained for the laminar boundary layer on a flat plate where subscripts p refer to the plate 1 to the free stream and e to the equilibrium temperature condition at the plate when compared with general results this relation exact for prandtl number o 1 gives a close approximation to croccos numerical results for o 0 725 and 1 25 up to using the above relation in conjunction with the approximate viscosity temperature relation suggested by chapman and rubesin and with youngs suggested first approximation for shearing stress it is shown that close approximations to displacement thickness and velocity distribution are given by and where and which serves to define c these have the advantage of being algebraic in form whereas previous results have involved complex numerical integrations for individual cases
CRAN	pressure distributions and flow patterns at m 4 on some delta wings of inverted v cross section pressure distributions and flow patterns at m 4 on some delta wings of inverted v cross section wind tunnel tests have been made to measure pressure distributions and to study flow patterns on a series of delta wings of inverted v cross section each of these wings was designed to have a plane shock wave in the plane of the leading edges at a chosen mach number and incidence it was found that for a wide incidence range about the design point the shock wave remained virtually attached to the leading edges and at each incidence the pressure was approximately constant over the lower surface
CRAN	the contraction of satellite orbits under the influence of air drag part i with spherically symmetrical atmosphere the contraction of satellite orbits under the influence of air drag part i with spherically symmetrical atmosphere the effect of air drag on satellite orbits of small eccentricity e 0 2 is studied analytically by a perturbation method on the assumption that the atmosphere is spherically symmetrical equations are derived which show 1 how orbital period and perigee distance vary with eccentricity as the orbit contracts and 2 how each of these quantities varies with time the equations of type 1 are nearly independent of the oblateness of the atmosphere in all the equations terms of order e and higher are usually neglected the results are also presented graphically in a manner designed for practical use the theory is to be extended to an oblate atmosphere in part ii and will later be compared with observation
CRAN	the contraction of satellite orbits under the influence of air drag the contraction of satellite orbits under the influence of air drag part ii with oblate atmosphere the effect of air drag on satellite orbits of small eccentricity e 0 2 was studied in part i technical note no g w 533 on the assumption that the atmosphere was spherically symmetrical here the theory is extended to an atmosphere in which the surfaces of constant density are spheroids of arbitrary small ellipticity equations are derived which show how perigee distance and orbital period vary with eccentricity and how eccentricity is related to time expressions are also obtained which give lifetime and air density at perigee in terms of the rate of change of period in most of the equations terms of order e and higher are neglected the results take different forms according as the eccentricity is greater or less than about 0 025 while circular orbits are dealt with in a separate section the results are also presented graphically in a manner designed for practical application and examples of the theory in use are given the influence of atmospheric oblateness is difficult to summarize fairly simultaneously assume theirworstvalues some of the spherical atmosphere results can be altered by up to 30 as a result of oblateness and 5 10 would be a more representative figure
CRAN	the contraction of satellite orbits under the influence of air drag part iii high eccentricity orbits 0 2 e 1 the contraction of satellite orbits under the influence of air drag part iii high eccentricity orbits 0 2 e 1 the effect of air drag on satellite orbits of eccentricity e less than between 0 2 and 1 is presented equations are derived which show how perigee distance and orbital period vary with eccentricity during the satellites life and how eccentricity is related to time and formulae are obtained for the lifetime and the air density at perigee in terms of the rate of change of period the results are also presented graphically and their implications and limitations are discussed
CRAN	determination of upper atmosphere air density and scale height from satellite observations determination of upper atmosphere air density and scale height from satellite observations a solution is obtained for the rate of change of semi major axis and perigee distance of a satellite orbit with time due to the resistance of the atmosphere the logarithm of air density is assumed to vary quadratically with height and the oblateness of the atmosphere is taken into account the calculation of perigee air density in terms of the rate of change of satellite period is dealt with and the method is applied to data at present available on six different satellites the variation of air density with height is obtained as in p 28 59 0 15  h 200 46 5 0 028 0 013 h 200 46 for h in the range of approximately 170 to 700 km where p is in grams c m h is in kilometres and standard deviations are given in brackets
CRAN	determination of upper atmosphere air density profile from satellite observations determination of upper atmosphere air density profile from satellite observations the theory previously developed for the changes in the perigee distance and semi major axis of a satellite orbit due to air drag is extended to enable the air density profile i e its relative variation with height to be derived from the motion of the orbits perigee the solution is first obtained in terms of the change in perigee distance and then in terms of the change in the radius of the earth at the sub perigee point the scale height in the 180 and 220 km altitude regions
CRAN	orbit decay and prediction of the motion of artificial satellites orbit decay and prediction of the motion of artificial satellites the rate of decay of elliptic satellite orbits due to atmospheric drag is investigated through variation of parameters and through use of an atmospheric model involving a power function between density and altitude this model is shown to fit actual conditions better than an exponential function the effects of the equatorial belt and the rotation of the earth are investigated the conclusion is reached that through these anomalies atmospheric drag substantially affects the orbit elements especially those defining the orbit plane an alternate approach of variation of parameters is presented by which a direct relation between period decay and instantaneous density conditions is established this approach by itself specifically adequate for prediction work also opens an avenue for systematic and unified evaluation of observed decay
CRAN	density of the upper atmosphere from analysis of satellite orbits further results density of the upper atmosphere from analysis of satellite orbits further results the method previously described has been refined by taking into account atmospheric rotation further results are given from satellites of latitude and season and day to night changes are reported
CRAN	earth satellite observations and the upper atmosphere earth satellite observations and the upper atmosphere atmospheric densities have been derived from artificial satellites in altitudes 200 700 km and from rockets up to about 200 km to consolidate the two sets of data h k kallmann suggested a model with a exact form of this curve has now been derived corrections for the is excellent very close correlation between atmospheric density variations h180 km and the solar 20 cm radiation implies that the origin of thesolar effectmay lie in the absorption of solar ultra violet radiation the atmospheric density curve between 180 and 200 km shows a temperature inversion in the fl layer it is not yet possible to decide whether solar ultra violet radiation as well as the solar he line and solar x ray radiation contribute to the heating of the fl layer diurnal and seasonal density variations at altitudes 210 562 and 660 km have been derived from variations in acceleration of three satellites sputnik 3 vanguard 1 and 2 group averages of diurnal variations are taken from different dates within the period may 15 1958 october 1 1959 physcal conditions in the upper atmosphere are briefly summarized thesolar effectoriginates in the fl layer as a result of heating by the solar he line at 304 a diurnal density variation at 210 km is only a few per cent absorption of solar electromagnetic radiation in the f2 layer and large heat conductivity cause intense diurnal density and temperature variations above
CRAN	latitude and diurnal variations of air densities from 190 to 280 km as derived from the orbits of discoverer satellites latitude and diurnal variations of air densities from 190 to 280 km as derived from the orbits of discoverer satellites variations in air density between day and night in the region 190 to 280 km are found to be small less than about 25 the presence of a possible region of local heating at about 220 km which disappears at night the night time density profile conforms with a constant scale height of 35 2 km no definite variation of air density with latitude is evident apart from a possible increase of about 60 which is indicated by rather limited polar region data for other latitudes and seasons a variation of less than about 20 is indicated
CRAN	scale height in the upper atmosphere derived from changes in satellite orbits scale height in the upper atmosphere derived from changes in satellite orbits thedensity scale heighth in the upper atmosphere is a measure of the rate at which air density p varies with height y being given by h p dp dy the value of h although important because with the molecular weight of the air it determines the air temperature has not as yet been well determined at heights above 200 km this note develops methods for finding h from the decrease in a satellites perigee height and from the decrease in the orbital period of a satellite in a small eccentricity orbit these methods are then applied to all the 14 satellites found suitable for the purpose the 44 values of h obtained for heights of 200 450 km represent an average over day and night and probably have errors s d of 5 10 it is found that as solar activity declined between 1957 and 1961 h decreased greatly e g at height 275 km h decreased from 60 km in early 1958 to height becomes much less rapid above 350 km and are consistent with the supposition that h had low values near 35 km at heights near 250 km for 1959 61 the results could be greatly extended in scope and improved in accuracy if more accurate orbits were available for short lifetime satellites
CRAN	on the coupling between heat and mass transfer on the coupling between heat and mass transfer in mixtures of two different gases or liquids one constituent will migrate spontaneously toward the warmer parts and the other toward the colder parts this phenomenon known as the soret effect and its converse the dufour effect were discovered as early as 1856 and 1873 respectively the two effects can also be considered as a simultaneous transport of mass and heat or as a coupling between heat and mass transfer the effects of this coupling have been neglected in all investigations of heat transfer in multicomponent flow systems so far on the a priori assumption that they are small in a recent publication however it was shown that they can be large in laminar boundary layer type flows with helium injection turbulent boundary layer measurements and an analysis conducted at the heat transfer laboratory clearly showed significant effects of the coupling on heat transfer and adiabatic wall temperature from additional measurements the results of which are presented below it is possible to separate the heat flux at the model wall into one part depending on the temperature gradient and a second part caused by the coupling it is shown that the latter exceeds the former and hence the coupling may not be neglected a priori without careful consideration
CRAN	cruise performance of channel flow ground effect machines cruise performance of channel flow ground effect machines the performance theory for high speed air cushion vehicles operating in close proximity to the ground is developed the analysis is restricted to cruise flight of vehicles of rectangular planform employing an air pressure seal between the ground and the vehicle along the two streamwise sides the variation of the optimum rearward deflection angle of the side jet pressure seal with speed for minimum overall power expenditure and maximum range is found it is concluded that a mixed propulsion system jet deflection plus propeller s is required volume flow and the corresponding fan pressure rise needed are also calculated the maximum lift drag ratio is determined the maximum thickness ratios of the vehicles are considered to be large compared with the ground height vehicle length ratio two dimensional airfoil theory is employed to show that close to stagnation conditions exist below the vehicles the lower surface lift pitching moment and aerodynamic center location are determined the flow over the upper surface is identified with flow over mounds upper surface lift coefficients are determined for typical mound shapes it is shown that high total lift coefficients are theoretically obtainable with almost zero induced drag the conventional induced drag power penalty is replaced by a sealing air power expenditure which is shown not to be excessive
CRAN	viscous and inviscid nonequilibrium gas flows viscous and inviscid nonequilibrium gas flows the condition of immediate freezing of the mass fraction of dissociated species of air at the equilibrium value behind the shock envelope prevails over a major portion of the flight spectrum associated with lifting re entry vehicles this is observed by means of order of magnitude considerations within the limits of the present knowledge of chemical reaction rates for the constituents of air accordingly investigations of the viscous and inviscid hypersonic flow about blunt and sharp leading edge slender bodies are made the investigations are generalized to consider an arbitrary degree of dissociation in the ambient free stream this condition is included in order to allow comparison with the flow field about a model in the test section of a hypersonic facility with dissociated air species present in the free stream inviscid frozen flow investigations are made for blunt and sharp leading edge slender body power law geometries the results indicate that the influence of a finite leading edge in inducing a pressure field far downstream blast wave analogy is considerably diminished for this model this conclusion is verified numerically by a characteristics solution for the hypersonic flow about a sonic wedge slab the viscous investigations consider the boundary layer interaction problem with a frozen degree of dissociation in this case as in the inviscid analysis the governing parameter is observed to be the ratio of the dissociation energy to the free stream kinetic energy the influence of this parameter on the boundary layer interaction mechanism for a highly cooled noncatalytic wall is presented the influence of a frozen flow field on skin friction and heat transfer is also discussed finally since higher mach number gas flows may be generated in wind tunnel nozzles where dissociation nonequilibrium effects are present the possibility of employing expansions with a controlled degree of dissociation as a technique for aerodynamic simulation is presented
CRAN	some features of supersonic and hypersonic flow about blunted cones some features of supersonic and hypersonic flow about blunted cones for a family of cones of various semiapex angles blunted by spherical caps shock shapes and surface pressure distributions have been obtained from both the belotserkovskii method and experiment these results are used to study convergence to conical flow conditions leading to both overexpansion and underexpansion on the surface with respect to the asymptotic conical pressures are described as well as conditions leading to bow shock inflection points conditions also exist for which a second shock may occur or for which the sonic line cannot touch the body surface the implications of these conditions for various blunt body methods are discussed for cones blunted in such a manner as to keep the flow entirely supersonic the flow field is found to exhibit certain similarities with that for genuine blunting this is related to the fact that the surface entropy layer for blunt bodies can be most influential in determining surface pressure in the interior of the flow field rather than near the surface
CRAN	flutter analysis of circular panels flutter analysis of circular panels the flutter problem of flat circular panels with edges elastically restrained against rotation has been formulated in terms of small deflection plate theory the panel is subjected to uniform all round tension or compression in its middle plane in addition to the supersonic compressible flow passing over its upper surface with still air below linear piston theory is employed to predict the aerodynamic load on the vibrating panel the problem is investigated by a rayleigh type analysis involving chosen modes of the panel as degrees of freedom in order to investigate the convergence of the solution the flutter mode shape of the clamped edge panel has been expressed in a series form in powers of r cos o the results of three  four  and five term approximations have displayed oscillatory behavior with apparently rapid convergence of the solution
CRAN	thermal effects on a transpiration cooled hemisphere thermal effects on a transpiration cooled hemisphere an approximate method is used to obtain the injection distribution which would exist on an isothermal transpiration cooled hemisphere in a supersonic stream this distribution is the same for both air and helium injection and is independent of the blowing level a model having this distribution was tested in the naval supersonic laboratory wind tunnel at a mach number of 3 53 it is concluded that the design technique is reasonably accurate data taken near the nose are compared with the theories for air and helium injection the agreement in the case of the reduction in heat transfer coefficient is good the values of insulated wall temperature obtained near the nose with helium injection are 8 percent above the local stagnation temperature and largely independent of injection rate it is believed that this phenomenon may be attributed to the thermal diffusion of the helium within the boundary layer air injection causes a slight reduction in the insulated wall temperature it is shown that injection of either air or helium at the hemisphere nose considerably reduces the heat flux at the surface the additional reduction in heat flux resulting from helium injection as opposed to air injection and predicted by existing theory is largely absent
CRAN	second order effects in laminar boundary layers second order effects in laminar boundary layers second order boundary layer disturbances are due to the displacement of the main flow by the boundary layer surface curvature freestream vorticity and slip a procedure for finding these is given for compressible flow of a perfect gas having a classically similar boundary layer solutions are given for the flat plate and circular cylinder and for the hypersonic axisymmetric stagnation point for the latter flow the dominant effect is that of vorticity which increases both shear and heat flux for the plate or cylinder the same conclusion tends to hold for high speed flow the vorticity effect is governed by the entire outer flow  not just the wall vorticity
CRAN	stagnation region in rarefied high mach number flow stagnation region in rarefied high mach number flow paper describes results of numerical solution of the viscous shock layer equations for axisymmetric stagnation region using the viscosity temperature law with w 0 65 pr 0 71 and y 1 25 purpose is to establish applicability of the simple approximation of w 1 obtained earlier to air at low reynolds numbers and low ratios of wall temperature to stagnation temperature using a reference temperature closely equal to eckerts to interpret the linear results excellent agreement is found in the limit of over a wide range of reynolds numbers covering fully merged shock layers as well as boundary layers with and without vorticity interaction agreement with recent experiments of ferri et al is as good as to be expected from shock layer approximation paper provides valuable extension of the applicability of the reference temperature concept
CRAN	low speed wind tunnel tests on a two dimensional aerofoil with split flap near the ground low speed wind tunnel tests on a two dimensional aerofoil with split flap near the ground pressure distributions have been measured on a 10 thick two dimensional aerofoil of r a e 101 section fitted with split flaps deflected at 15 and 55 measurements were made at two distances above a ground plate and also without the ground plate the results have been integrated to give the sectional lift drag and pitching moment coefficients
CRAN	calculated lift distributions in incompressible flow on some sweptback wings calculated lift distributions in incompressible flow on some sweptback wings in the course of a larger survey of some aerodynamic characteristics of a family of sweptback wings the low speed lift distributions were calculated the 35 planforms considered cover a range of leading edge sweep angles from 55 to 70 and aspect ratios from 2 to 3 9 the results are given here together with a comparison with other calculations and with experimental results on one particular wing
CRAN	an extension of the method of generalised conical flows for lifting wings in supersonic flow an extension of the method of generalised conical flows for lifting wings in supersonic flow the method of generalised conical flows has previously been developed subject to the condition that the upwash divided by the streamwise co ordinate to the power k where k is the order of the conical flow must have vanishing k 1 th derivative with respect to the conical co ordinate in the present note this restriction is removed the results are also used to discuss the effect of the application of the leading edge attachment condition on the wing pressure and geometry
CRAN	effects of leading edge bluntness on flutter characteristics of some square  planform double wedge airfoils at a mach number of 15 4 effects of leading edge bluntness on flutter characteristics of some square  planform double wedge airfoils at a mach number of 15 4 results are presented from a wind tunnel investigation in helium flow at a mach number of 15 4 the models were square planform double wedge shaft mounted airfoils with leading  and trailing edge radii of 0 1 3 and 6 percent chord in general the tests indicate that bluntness effects on the model flutter characteristics are stabilizing as the leading edge radius is increased from 0 to destabilizing with further increase in bluntness results of flutter calculations made by using newtonian theory aerodynamics and a combination of newtonian theory and piston theory aerodynamics in conjunction with an uncoupled two mode analysis are compared with experimental results the piston theory results accurately predicted flutter speeds for the models with
CRAN	heat transfer and pressure distributions on a hemisphere cylinder and a bluff afterbody model in methane air combustion products and in air heat transfer and pressure distributions on a hemisphere cylinder and a bluff afterbody model in methane air combustion products and in air an experimental investigation has been made to indicate the validity of using methane air combustion products as the test medium for aerodynamic heating and loading tests tests were conducted on a hemisphere cylinder and on a bluff afterbody model both in methane air combustion products and in air alone and covered a range of mach numbers from 6 to the data showed that the nondimensional heating rate distribution along a hemisphere cylinder as obtained in combustion products was in good agreement with that obtained in air and the results were in reasonable agreement with theory the stagnation point heating rates in air and in combustion products over the hemisphere cylinder agreed within 10 percent of the theoretical values the pressure distributions around a hemisphere cylinder obtained from tests in combution products were in good agreement with those obtained in air and could be predicted by newtonian flow theory the tests in combustion products of a bluff afterbody model produced nondimensional heat transfer coefficients which were in fair agreement with results obtained in air
CRAN	pressure distribution induced on a flat plate at a free stream mach number of 1 39 by rockets exhausting upstream and downstream pressure distribution induced on a flat plate at a free stream mach number of 1 39 by rockets exhausting upstream and downstream an experimental investigation was made of the pressures induced on a flat plate at a free stream mach number of 1 39 by a supersonic rocket jet exhausting upstream and downstream measurements of the pressure distribution on a flat plate were made at zero angle of attack for 11 different locations of the jet exhaust nozzle beneath the wing measurements were made at ratios of rocket exit total pressure to free stream static pressure from 6 to 60 and at a reynolds number per foot of approximately 10 times 10 to the power of 6 the rocket when exhausted upstream produced a strong shock that moved further upstream with increasing rocket exit total pressure ratio positive incremental normal force coefficients were obtained at all test positions data at 11 test positions are tabulated for rocket on and rocket off pressure coefficients as well as for incremental pressure coefficients for the 48 orifices of the flat plate for the range of ratio of rocket exit total pressure to free stream static pressure of the investigation changing the location of the model with respect to the plate had a negligible effect when the rocket was varied in the chordwise direction but the pressure coefficients were reduced as the rocket was lowered away from the flat plate wing
CRAN	an integral equation relating the general time dependent lift and downwash distributions on finite wings in subsonic flow an integral equation relating the general time dependent lift and downwash distributions on finite wings in subsonic flow an integral equation for obtaining the unsteady air forces on finite wings in subsonic compressible flow is presented this equation is applicable for any arbitrary time dependent motion and can be utilized for flexible as well as rigid wings the approach involves the derivation of an integral equation relating the unknown pressure the form of the equation is such that it should lend itself readily to modern high speed computers for obtaining pressure distributions special cases of the integral equation are treated for two dimensional incompressible flow and are presented in an appendix
CRAN	longitudinal aerodynamic characteristics at low subsonic speeds of a highly swept wing utilizing nose deflection for control longitudinal aerodynamic characteristics at low subsonic speeds of a highly swept wing utilizing nose deflection for control an investigation has been conducted in the langley 7  by 10 foot transonic tunnel at low subsonic speeds to determine the longitudinal aerodynamic characteristics associated with deflection of the nose section of a highly swept delta wing having an aspect ratio of 1 33 in order to illustrate the effectiveness of this forward control the longitudinal control characteristics are also presented for the wing with upper and lower surface split flaps located at the trailing edge comparison between the longitudinal aerodynamic characteristics of the wing utilizing the nose control and those of the wing utilizing the upper surface split flap located at the trailing edge indicated similar control effectiveness for high control deflections 15 and similar values of trimmed lift drag ratio with increasing lift coefficient use of the nose control however indicated a lower value of trimmed angle of attack for a given value of trimmed lift coefficient than that realized from use of the upper surface split flap further reductions in trimmed angle of attack for a given value of trimmed lift coefficient may be realized from deflection of the lower surface split flap at the wing trailing edge in combination with the nose control and would be accompanied by large reductions in lift drag ratio
CRAN	analytical study of the tumbling motions of vehicles entering planetary atmospheres analytical study of the tumbling motions of vehicles entering planetary atmospheres the tumbling motion of vehicles entering planetary atmospheres is analyzed a differential equation governing the tumbling motion its arrest and the subsequent oscillatory motion is obtained and identified as the equation for the fifth painleve transcendant an approximate analytical solution for the transcendant is derived comparisons with results obtained from numerical integration of the exact equations of motion indicate that the solution for the angle of attack history is sufficiently accurate to be of practical use
CRAN	the design of structures to resist jet noise fatigue the design of structures to resist jet noise fatigue the design of structures to resist jet noise fatigue demands a knowledge of a wide range of subjects from pure acoustics at one hand to metal physics at the other at the present time the various aspects of the problem are not sufficiently well know quantitatively for a purely theoretical design study to be made never  the less a knowledge of the behaviour of typical forms of construction in noise environments can be used with a limited amount of theoretical work to indicate tne most efficient types of structure this approach to the problem is adopted in this lecture as it seems to be the most promising one available at the moment it must be emphasized however that although some progress has been made in dicsovering the behaviour of a structure subjected to noise it is not possible to estimate the life of any component at the drawing board stage some prototype strain measurements and proof testing are therefore essential if one is to prove the integrity of the design within the structural limits of single skin construction set in this lecture the main conclusion to be reached is that no reasonable estimate of fatigue life can yet be made in the drawing board stage of a structure nevertheless a study of the form of behaviour of typical structures has led to a theoretical simplification of the problem of skin vibration from this it has been possible to suggest an optimum deisgn for a skin stiffened by stringers a suggestion for an optimum design of skin and rib for control surfaces to minimise stresses at the rib skin intersection is put forward but no experience can check this yet the most resonable basis for the future estimation of fatigue life of a component appears to be the random s n curve and consierable effort should be made to obtain the necessary test data the life expectation of a new design will be uncertain and some proof testing is essential if the integrity of structure in high noise levels 150 db is to be guaranteed
CRAN	reduction of the clamped plate to two membrane problems with an application to uniformly loaded sectors reduction of the clamped plate to two membrane problems with an application to uniformly loaded sectors the clamped plate problem in the classical theory for the small deflection bending of flat plates is reduced to the solution by variational methods of two successive membrane problems the first requires the least square minimisation of the average curvature of the deflected surface while the second problem concerns the integral of the gaussian curvature there is a similar reduction for extensional problems where the boundary tractions are specified the method is demonstrated by giving three distinct solutions to the problem of the clamped sector under a uniformly distributed load one solution is of special interest because it is derived from a single membrane problem numerical data are given
CRAN	the buckling strength of a uniform circular cylinder loaded in axial compression the buckling strength of a uniform circular cylinder loaded in axial compression the theoretical estimation of the buckling strength of a cylinder loaded in axial compression is improved by the use of a more representative deflected form for the buckled cylinder than has previously been used kempners buckling strength for dead weight loading is reduced by 18 the presentation of the magnitude and distribution of the constraint system required to maintain the mode is novel and instructive
CRAN	an investigation of wing aileron flutter using ground launched rocket models an investigation of wing aileron flutter using ground launched rocket models control surface flutter of the wing torsion control rotation type has been investigated for an unswept wing with an under massbalanced half span outboard aileron thirteen pairs of wings were tested using ground launched rocket driven vehicles and a range of values of aileron natural frequency was covered the test results showed considerable scatter but enabled upper and lower limits of a flutter boundary to be determined approximately it was established that aileron flutter could be eliminated on the models tested provided the aileron frequency exceeded the wing torsional frequency by 20 per cent or more in this condition the models were also free from single degree of freedom flutter
CRAN	a study of the cantilever square plate subjected to a uniform loading a study of the cantilever square plate subjected to a uniform loading plate problems involving free edges have been historically difficult to solve particularly when two free edges are adjacent resulting in a free corner the cantilevered square plate subjected to a transverse loading is one such problem for which an exact solution has not been achieved in the present paper results obtained by various approximate methods are presented for this problem for the case of a uniform loading solutions obtained by the authors using the technique of point matching and the rayleigh ritz method are compared with previously published finite difference and experimental results and with bernoulli euler beam and plane strain approaches numerical results for deflections slope components bending and twisting moments and transverse distributed shears are presented for a relatively fine gridwork of points on the plate boundary and within the interior the antielastic curvature is exhibited by all methods except beam theory all methods present the interesting conclusion that the free edge deflection is greater when the plate is treated as a plate rather than a beam
CRAN	thermodynamic coupling in boundary layers thermodynamic coupling in boundary layers experimental results gathered in recent years for binary mixture mass transfer models are shown to yield consistent evidence of discrepancies with analytic considerations specifically measured recovery temperatures are appreciably higher than those predicted while heat transfer coefficients are satisfactorily reproduced it is shown on the basis of both approximate and exact solutions for plates and stagnation points that the discrepancies in previous results are related to thermal diffusion effects a major influence being apparent in application of the surface boundary condition for an adiabatic wall as a result some reexamination is necessary of past criteria for mass addition effects as they pertain to specific injected media a prime example is the equivalence of helium and air as coolants despite the heretofore suggested preference for low density injectants on a perfect gas basis ref 16
CRAN	thermal diffusion effects on energy transfer in a turbulent boundary layer with helium injection thermal diffusion effects on energy transfer in a turbulent boundary layer with helium injection a circular cylinder with two inch diameter and with a porous wall fabricated out of woven wire material was aligned with its axis parallel to an air stream with approximately 100 ft sec velocity helium gas was injected into the turbulent boundary layer through the cylinder walls at a uniform rate in the range 1 55 x 10 to 1 08 x 10 of the free stream mass velocity the local energy transfer along the cylinder was measured at various values of the wall temperature level for the situation that the energy flows from the cylinder to the boundary layer and vice versa the results showed clearly that the wall temperature for zero energy transfer   the adiabatic wall temperature   was larger than the free stream temperature by up to about 40 f although viscous dissipation effects are negligible this temperature excess increases with increasing injection rate and is independent of reynolds number an analysis in which the laminar sublayer is treated as couette flow with helium injection and which includes thermal diffusion in this layer is formulated the results show appreciable thermal diffusion effects on adiabatic wall temperature increasing it over its value for zero injection by amounts of the same order of magnitude as found by measurements thermal diffusion however has negligible effects on the heat transfer coefficient its effects on the concentration and temperature distribution are discussed and are shown to produce appreciable modifications in the latter
CRAN	bending of a uniformly loaded rectangular plate with two adjacent edges and the others either simply supported or free bending of a uniformly loaded rectangular plate with two adjacent edges and the others either simply supported or free the distribution of deflection and bending moment in a uniformly loaded rectangular plate having two adjacent edges clamped and the others either simply supported or free are obtained by a method of superposition numerical values are given for square plates and in one case the results are compared with those obtained by another method
CRAN	the approximate analysis of certain boundary value problems the approximate analysis of certain boundary value problems a simple method is given which is suitable for the approximate analysis of certain boundary value problems including for example the small deflections of clamped plates and the torsion of prismatic bars the analysis is particularly simple and lends itself well to the use of the digital computer the method is applied here to four problems the uniformly loaded clamped square and equilateral triangle plates and the torsion of bars of square and hexagonal cross section the results agree well with the exact solutions where these are known
CRAN	the hovercraft   a new concept in maritime transport the hovercraft   a new concept in maritime transport the hovercraft is the first operational british project in the ground effect machine field although there has for a number of years been a tentative searching after the principles underlying such machines it is only now that their possibilities as commercial transport and service craft are beginning to be developed since the hovercraft is a new vehicle the appearance of the saunders roe sr n1 a manned experimental craft excited considerable public attention and there have been a number of descriptive articles in the press papers of a more technical type on ground effect machines are now beginning to appear and it is to be expected that these will rapidly increase in number especially since american interest in both the commercial and defence fields is expanding fast the authors of the present paper have therefore concentrated attention upon features about which they had something personal to say and which they consider to be of particular significance for assessing the possibility of the hovercraft becoming important in maritime transport these features are   the hovercraft as a fundamentally new principle in the transport field the powering requirements and resistance characteristics the likely operating costs of hovercraft in comparison with other forms of maritime transport in addition relatively brief descriptions of the history and the current work being undertaken on the ground effect machine and of the design construction and testing of the saunders roe sr n1 are provided the final section discusses outstanding problems and some future possibilities
CRAN	some design problems of hovercraft some design problems of hovercraft analysis of the influence various aerodynamic parameters have on the performance of a simple peripheral jet system power weight ratio lift drag ratio and effect of jet angles and thickness are each considered structural requirements optimum cushion pressure and dynamic stability over waves are examined and then related to the economics of ground effect machine operation
CRAN	heat transfer to separated and reattached subsonic turbulen flows obtained downstream of a surface step heat transfer to separated and reattached subsonic turbulen flows obtained downstream of a surface step local heat transfer coefficients and recovery factors are presented for separated and reattached turbulent flows as obtained by a downward step in an otherwise flat surface in a two  dimensional subsonic air flow the region downstream of the step the focus of this investigation contained a region of separated flow with reattachment at about five step heights downstream followed by a section of reattached flow the salient feature of the results is the maximum in the local heat transfer coefficient at the reattachment point with values thereof diminishing in the separated region and also in the reattached region where they tend toward values characteristic of turbulent boundary layer flow it is found that for most of the region the heat transfer coefficient depends on the velocity to about the 0 8 power though a decreased dependence may exist in the separated region recovery factors have the characteristically low values associated with separated flows and do not attain values typical of turbulent boundary layer flows within the downstream lengths available
CRAN	pressure distribution on two dimensional wings near the ground pressure distribution on two dimensional wings near the ground a simple method of calculating the pressure distribution in incompressible flow on two dimensional aerofoils of arbitrary section at moderate distances from the ground is developed comparisons with an exact potential flow solution and with measurements on a 10 thick aerofoil of rae 101 section provide a satisfactory verification of the adequacy of the method but it is shown that it is necessary to take account of the boundary layer on the aerofoil in the calculations
CRAN	transient magnetohydrodynamic duct flow transient magnetohydrodynamic duct flow parallel flow of an electrically conducting viscous incompressible fluid in a rectangular duct with transverse magnetic field is considered the walls of the duct which are parallel and perpendicular to the imposed magnetic field are taken to be nonconducting and perfectly conducting respectively assuming the fluid to be at rest at the initial moment exact solutions for the velocity and magnetic field components are obtained in the form of convolution integrals taking the longitudinal pressure gradient as an arbitrary given function of time later taking a step function for the pressure gradient these expressions are integrated for this case the effect of the strength of the imposed magnetic field on the development behavior of the flow is studied it is found that except for very large magnetic fields the flows are over damped
CRAN	on the propagation and structure of the blast wave part 1 on the propagation and structure of the blast wave part 1 as a continuation of part 1 j phys soc japan 8 1953 662 the second approximation for the propagation and structure of a blast wave is now discussed the solution for r 1 4 is obtained by a numerical method using the results of the first approximation obtained in part 1 by use of this solution u r curves distance time curves and the changing feature of distributions of velocity pressure and density behind the shock front are discussed further the approximate solution of the equation is discussed by a refinement of the wkb method due to imai
CRAN	effects of boundary layer displacement and leading edge bluntness on pressure distribution skin friction and heat transfer of bodies at hypersonic speeds effects of boundary layer displacement and leading edge bluntness on pressure distribution skin friction and heat transfer of bodies at hypersonic speeds results are presented of an investigation to determine the effect of boundary layer displacement and leading edge bluntness on surfaces in hypersonic flow the presence of the boundary layer and the blunt leading edge induce pressure gradients which in turn affect the skin friction and heat transfer to the surface methods for predicting these phenomena on two dimensional surfaces are given and a brief review of recent three dimensional results is presented
CRAN	departure from dissociation equilibrium in a hypersonic nozzle departure from dissociation equilibrium in a hypersonic nozzle the equations of motion for the flow of an ideal dissociating gas through a nearly conical nozzle have been solved numerically assuming a simple equation for the rate of dissociation and a number of different values of the rate constant the results of these calculations suggest that deviations from dissociation equilibrium will occur in the nozzle if the rate constant lies within a very wide range of values they also suggest that once such a deviation has begun the gas will very rapidly freeze so that the dissociation fraction will remain almost constant if the flow is expanded further or even if it passes through a constant area test section an approximate method of solution making use of this property of sudden freezing of the flow has been developed and applied to the problem of estimating the deviations from equilibrium under a wide range of conditions if all the assumptions made in this report are accepted then lack of dissociation equilibrium may be expected in the working sections of hypersonic wind tunnels and hypersonic shock tubes it is shown however that the flow behind a normal shock wave in such a wind tunnel will not be greatly affected by any freezing that may take place in the nozzle upstream of the shock wave even so the stand off distance of a shock wave in front of a blunt model may be quite sensitive to deviations from equilibrium
CRAN	interferometric studies of supersonic flows about truncated cones interferometric studies of supersonic flows about truncated cones fringe shifts on interferograms of flows at m 2 45 about variously truncated 15 half angle cone cylinders in free flight in a pressurized range have been examined for similarity of the flow fields occurrence of scale effects and convergence to conical flow it was found that flows over similar objects with equal tip reynolds numbers were similar and that convergence to conical flow occurred before the disturbance at the tip had been reflected the second time along characteristics to the body density distributions have been determined and a number of comparisons have been made with theoretical predictions
CRAN	review of panel flutter and effects of aerodynamic noise part i panel flutter review of panel flutter and effects of aerodynamic noise part i panel flutter with the development of high speed aircraft and missiles vibration of panels has become a problem of practical significance many of the failures of the early german rockets after attaining supersonic speed have been attributed to the development of such panel oscillations it appears this phenomenon is not of much concern in the subsonic speed range however in the supersonic speed range panels may develop oscillations which cause instability of the structure this effect has been exhibited experimentally under controlled laboratory conditions motion is limited and buckling may not be a serious design problem in these cases panel flutter is still of importance because of its effect on the fatigue life and the allowable stresses for design of the panel material the oscillations of panels may be due either to aerodynamic force induced by the motion of the panel or to aerodynamic noise or buffeting irregular motion induced by turbulence in the flow the interaction between aerodynamic forces and panel motions usually referred to as panel flutter has been investigated by several workers in recent years since the problem is too complex to be dealt with in its entirety simplifying assumptions have been made in these investigations the literature is marked by a certain degree of controversy over the validity of these assumptions and the applicability of the results obtained a brief review of the literature with reference to several of the approximations made and the results obtained follows
CRAN	nonuniform shear flow past cylinders nonuniform shear flow past cylinders a general method is described whereby an approximation of any desired degree of accuracy to the stream functions for two types of variable shear flows past finite cylinders can be obtained the two shear distributions in the free stream can be approximated to the linear shear distribution and the shear present in an unretarded incompressible boundary layer respectively in every case the stagnation streamline is displaced from the position opposite the line of symmetry of the cylinder and general expressions are obtained for this displacement the line of symmetry may be in the direction of or perpendicular to the direction of flow the two particular examples cited are those of a general elliptic cylinder and cylinders of the form where and being the polar coordinates and 2p the maximum width of the cylinder
CRAN	the fundamental solution for small steady three dimensional disturbances to a two dimensional parallel shear flow the fundamental solution for small steady three dimensional disturbances to a two dimensional parallel shear flow after a brief review of methods of calculating the flow fields produced by disturbances in rotational basic flows the author points out a fundamental difficulty in the treated as a perturbation of the disturbance field that would occur if the basic flow were uniform slow attenuation of the secondary flow disturbance with distance from the obstacle the author conjectured same j 1 the trouble was caused by nonuniform validity of the approximation sequence in the region far from the obstacle the analogy with stokes and whiteheads paradoxes is mentioned and a solution analogous to oseens is suggested one in which disturbances but not the shear are assumed to be small in this paper such a solution is found and is shown to overlap with the small shear secondary flow solution the basic flow is a parallel steady inviscid two dimensional shear flow the fundamental solution due to a weak source is sought the method of fourier transforms is used simple solutions are found for a uniformly sheared basic flow where the result coincides with the secondary flow solution and for an exponential basic flow profile in the general case it is assumed that the parallel basic flow becomes uniform at where the x axis lies in the flow direction the character of the solution is determined by studying its hankel transform especially for the class of flows where the total variation of the basic stream speed v y is small an interpretation in terms of images due to m b glauert is given and finally the relationship of the present work to theories of the displacement of the stagnation streamline displacement effect of pitot tubes is discussed
CRAN	summary of laminar boundary layer solutions for wedge type flow over convection and transpiration cooled surfaces summary of laminar boundary layer solutions for wedge type flow over convection and transpiration cooled surfaces a summary of exact solutions of the laminar boundary layer equations for wedge type flow useful in estimating heat transfer to such arbitrarily shaped bodies as turbine blades is presented the solutions are determined for small mach numbers and a prandtl number at the wall of 0 7 ranges of mainstream pressure gradients and rates of coolant flow through a porous wall are considered for the following cases 1 small temperature changes in the boundary layer along a constant  and along a variable temperature wall and 2 large temperature changes in the boundary layer along a constant temperature wall dimensionless forms of heat transfer and friction parameters and boundary layer thicknesses are tabulated the results indicate that coolant emission and increased stream to wall temperature ratios diminished the friction and heat transfer for a constant wall temperature for a variable wall temperature with small temperature differences in the boundary layer the friction was unaffected but the heat transfer was greatly increased for increased wall temperature gradient heat transfer results in the literature reveal that transpiration cooling is much more effective for prandtl numbers of the order of 5 0 than for 0 7
CRAN	theoretical and experimental investigation of aerodynamic heating and isothermal heat transfer parameters on a hemisphere nose with laminar boundary layer at supersonic mach numbers theoretical and experimental investigation of aerodynamic heating and isothermal heat transfer parameters on a hemisphere nose with laminar boundary layer at supersonic mach numbers the effect of a strong negative pressure gradient upon the local rate of heat transfer through a laminar boundary layer on the isothermal surface of an electrically heated cylindrical body of revolution with a hemispherical nose was determined from wind tunnel tests at a mach number of 1 97 the investigation indicated that the local heat transfer parameter based on flow conditions just outside the boundary layer decreased from a value of 0 65 0 10 at the stagnation point of the hemisphere to a value of 0 43 0 05 at the junction with the cylindrical afterbody because measurements of the static pressure distribution over the hemisphere indicated that the local flow pattern tended to become stationary as the free stream mach number was increased to 3 8 this distribution of heat transfer parameter is believed representative of all mach numbers greater than 1 97 and of temperatures less than that of dissociation the local heat transfer parameter was independent of reynolds number based on body diameter in the range from 0 6x10 to 2 3x10 the measured distribution of heat transfer parameter agreed within theoretical distribution calculated with foreknowledge only of the pressure distribution about the body this method applicable to any body of revolution with an isothermal surface combines the mangler transformation stewartson transformation and thermal solutions to the falkner skan wedge flow problem and thus evaluates the heat transfer rate in axisymmetric compressible flow in terms of the known heat transfer rate in an approximately equivalent two dimensional incompressible flow measurements of recovery temperature distributions at mach numbers of 1 97 and 3 04 yielded local recovery factors having an average value of 0 823 0 012 on the hemisphere which increased abruptly at the shoulder to an average value of 0 840 0 012 on the cylindrical afterbody this result suggests that the usual representation of the laminar recovery factor as the square root of the prandtl number is conservative in the presence of a strong accelerating pressure gradient
CRAN	viscous flow along a flat plate moving at high speeds viscous flow along a flat plate moving at high speeds by the distortion of coordinates it is shown that in the case of supersonic viscous flow past a flat plate the boundary layer and simple wave theories can be combined to give a complete representation of the velocity and pressure fields consistent first order solutions are considered an expression for the induced pressure on the plate correct to the second order is obtained at high mach numbers the important parameter satisfies the hypersonic similarity law and for arbitrary mach and reynolds numbers and for different gases the theoretical curve correlates closely the experimental data asymptotic shock curve and skin friction coefficient are also deduced but the experimental verifications are yet to be made
CRAN	the boundary layer on a flat plate in a stream with uniform shear the boundary layer on a flat plate in a stream with uniform shear the incompressible laminar boundary layer on a semi infinite flat plate is considered when the main stream has uniform shear a solution is obtained for the first two terms of an asymptotic solution for small viscosity it is shown that one of the principal effects of free stream vorticity is to introduce a modified pressure field outside the boundary layer region
CRAN	on the theory of hypersonic gas flow with a power law shock wave on the theory of hypersonic gas flow with a power law shock wave plane and axisymmetric hypersonic gas flows are considered with shock waves of very great intensity that have a power law form on the basis of an investigation of the portions of the flow with high entropy adjoining the surface of the body not necessarily for a shock wave of the given form it is shown that the use in the flow problem of the exact solution for the corresponding unsteady self similar gas motion requires a supplementary refinement of the thickness of the high entropy layer a method is shown for introducing such a correction and constructing the shape of the body contour on which is to be applied the pressure distribution obtained on the basis of the theory of small disturbances
CRAN	blunt body heat transfer at hypersonic speed and low reynolds numbers blunt body heat transfer at hypersonic speed and low reynolds numbers an analytical method for the determination of effect of shock curvature on heat transfer in the region of the nose has been developed it is shown that for practical body shape the viscous terms in the navier stokes equations are not important in the region of the flow far from the wall and the displacement thickness can be neglected then the flow can be approximately represented by an inviscid flow solution having as boundary conditions the body shape which is not affected by the reynolds number and by a boundary layer type of flow near the wall having appropriate boundary conditions this approach permits us to determine the heat transfer in the region of the nose even at very low reynolds numbers experimental results are presented the experimental results agree with the values given by the analysis
CRAN	hypersonic shock layer theory of the stagnation region at low reynolds number hypersonic shock layer theory of the stagnation region at low reynolds number cheng h k hypersonic flow at low reynolds number is studied utilizing the shock layer concept the present formulation takes into account the salient features of the transport processes within the shock layer in a manner consistent with the shock layer approximation the rankine hugoniot shock relations are modified to include contributions due to heat conduction and viscous effects immediately behind the shock the specific problem of an axisymmetric stagnation region is treated the flow regimes for this problem can be classified according to whether or not the transport effects are important immediately behind the shock in one regime where the ordinary rankine hugoniot relations hold across the shock the vorticity interaction theory based on the boundary layer approximation is shown to be sufficient in the other regime where the rankine hugoniot relations have to be modified but the continuum flow model applies an approximate an analytical solution is obtained this solution reveals a substantial reduction of the temperature behind the shock and of the shock stand off distance in the presence of strong surface cooling the present study is intended to provide a knowledge to bridge the gap between the free molecule flow regime and that of the boundary layer via the continuum theory in this respect the solution obtained appears to be satisfactory in that it yields the correct free molecule limits for the skin friction and surface heat transfer rate
CRAN	measurements of stagnation point heat transfer at low reynolds number measurements of stagnation point heat transfer at low reynolds number measurements of stagnation point heat transfer are presented in the reynolds number range between the free molecular flow and the range where modified boundary layer theory still applies the measurements are compared with the analytical methods set forth by ferri zakkay and ting the results show smooth transition between the two regions and indicate that the predicted reynolds number for which the modified boundary layer theory can be used is in agreement with experiments in the lower range of reynolds number the ratio of decreases and reaches a value of 1 at a reynolds number of 40
CRAN	subsonic potential flow past a sphere inside a cylindrical duct subsonic potential flow past a sphere inside a cylindrical duct the subsonic potential flow of a compressible fluid past a sphere in an infinite medium was first determined by rayleigh subsequently caplan and tamada extended the solution to include the fourth power of the mach number to the authors knowledge no solution for subsonic flow past a sphere in a finite medium has been published it is the purpose of this note to present a solution for subsonic potential flow past a sphere inside a circular cylindrical duct
CRAN	on blunt body heat transfer at hypersonic speed and low reynolds number on blunt body heat transfer at hypersonic speed and low reynolds number a discussion of differences arising between experimental and analytical results in particular those due to inconsistencies introduced in the presentation of data and the way the comparison is made
CRAN	pressure and boundary layer measurements on a two dimensional wing at low speed pressure and boundary layer measurements on a two dimensional wing at low speed results are given of pressure measurements and boundary layer traverses on a two dimensional wing with 10 per cent rae 101 section at reynolds numbers of 1 6x10 and 3 2x10 these results which have been integrated to give lift drag and aerodynamic centre characteristics are used to check some calculation methods for the growth of the turbulent boundary layer and for the effect of a known boundary layer on the pressure distribution it is concluded that the calculation of the boundary layer still needs a little refinement before it is accurate enough to predict viscosity effects on pressure distribution lift drag and aerodynamic center but that these effects can be calculated if the actual boundary layer characteristics are known
CRAN	tunnel interference effects tunnel interference effects the problems of solid blockage wake blockage lift effect and the influence of boundary constraint at high mach number are considered in detail corrections are given for various open and closed tunnels rectangular circular and octagonal and different speeds two and three dimensional flows with several aerofoils and wings other interferences include the wall boundary layer gradient of static pressure and problems with the working fluid used
CRAN	investigation of full scale split trailing edge wing flaps with various chords and hinge locations investigation of full scale split trailing edge wing flaps with various chords and hinge locations an investigation was conducted in the n a c a full scale wind tunnel on a small parasol monoplane equipped with three different split trailing edge wing flaps the object of the investigation was to determine and correlate data on the characteristics of the airplane and flaps as affected by variation in flap chord flap deflection and flap location along the wing chord the chords of the flaps were 10 20 and 30 percent of the wing chord and each flap was tested at deflections from 0 to 75 when located successively at 68 80 and 88 8 percent of the wing chord aft of the leading edge the investigation included force tests pressure distribution tests and downwash surveys the results give the lift the drag and the pitching moment characteristics of the airplane the flap forces and moments the pressure distribution over the flaps and wing at one section and the downwash characteristics of the flap and wing combinations an increase in flap chord or distance of the flap from the leading edge of the wing increased the lift of the airplane but had an adverse effect on the wing pitching moment the ld ratio of the airplane decreased with increase in flap deflection or flap chord flap normal force coefficients were primarily a function of flap deflection and were relatively independent of flap chord hinge axis location and airplane attitude the location of the flap center of pressure in percentage of flap chord aft of the hinge axis remained practically constant irrespective of airplane attitude and of flap deflection chord or location flap hinge moment coefficients varied with a power of flap chord greater than the square so that with regard to hinge moments narrow flaps were the most efficient in producing a given increase in lift split trailing edge flaps materially affected the magnitude and distribution of pressures over the entire wing profile at low angles of attack the predominant effect of the flaps was to increase positively the lower surface pressures at high angles of attack to increase negatively the upper surface pressures downwash surveys indicated that horizontal tail planes located above the wing chord line would be more effective than those below the chord in counteracting the increased diving moment of the airplane with flaps deflected
CRAN	the shapes and lift dependent drags on some sweptback wings designed for m 1 2 the shapes and lift dependent drags on some sweptback wings designed for m 1 2 the camber and twist distributions needed to produce a constant span wise  distribution and certain linear chordwise load distributions have been calculated by linearised supersonic theory at for a set of 34 thin sweptback wings the wing planforms cover a range of aspect ratios from 2 0 to 3 5 and leading edge sweep angles from 55 to 70 both leading and trailing edges are subsonic at the design mach number and the slenderness parameter is between 0 19 and 0 40 the lift dependent vortex and wave drags associated with these loadings have also been calculated and appear not to be excessive in almost all the cases considered
CRAN	pressure distribution and surface flow on 5 and 9 thick wings with curved tip and 60degree sweepback pressure distribution and surface flow on 5 and 9 thick wings with curved tip and 60degree sweepback extensive tables are given of pressure coefficients measured at reynolds numbers from 1 3x10 to 3 9x10 on two half models of identical planform with 5 rae 101 and 9 rae 101 streamwise sections the planform of aspect ratio 3 899 has a straight trailing edge with 60degree of sweepback constant chord over most of the span and a parabolic outer portion of the leading edge curving to a pointed tip the overall wing characteristics are obtained from integrated normal pressures and are compared with lifting surface theory the low speed experimental pressure distributions and surface oil flow patterns are analysed and discussed in relation to the onset of separation and the distinct vortex flows that develop at high incidence series of contrasting upper surface isobars illustrate some features of the different stalling processes of the two wings the direct influence of the main vortex on local surface pressures is assessed in general terms a fuller appraisal of secondary surface flow is obtained from the oil patterns observations in water and measurements of high suction near the trailing edge studies of the extent of leading edge stall and location of part span vortices in particular two simultaneous leading edge vortices on the thinner wing follow from further analysis of local surface pressures after a detailed discussion of the effect of reynolds number and the distinct types of separated flow a few results with leading edge roughness are considered in relation to scale effect on separation and the extensive influence of part span roughness
CRAN	a simple method for calculating the span and chordwise loading on straight and swept wings of any aspect ratio at subsonic speeds a simple method for calculating the span and chordwise loading on straight and swept wings of any aspect ratio at subsonic speeds the methods of the classical aerofoil theory are used to derive a general theory for wings of any given planform the load over the whole surface of a given wing can be calculated at a given subcritical mach number and the procedure is as simple and rapid as that of the classical aerofoil theory the calculated results are confirmed by experiments
CRAN	methods for calculating the lift distribution of wings subsonic lifting surface theory methods for calculating the lift distribution of wings subsonic lifting surface theory this report contains some fairly simple and economic methods for calculating the load distribution on wings of any plan form based on the conceptions of lifting surface theory the computer work required is only a small fraction of that of existing methods with comparable accuracy this is achieved by a very careful choice of the positions of pivotal points by plotting once for all those parts of the downwash integral which occur frequently and by a consequent application of approximate integration methods similar to those devised by the author for lifting line problems the basis of the method is to calculate the local lift and pitching moment at a number of chordwise sections from a set of linear equations satisfying the downwash conditions at two pivotal points in each section interpolation functions of trigonometrical form are used for spanwise integration both in setting up the downwash equations and in getting the resultant forces on the wing from the local forces the preliminary chordwise integrations for the downwash are predigested in a series of charts figs 1 6 it is these which make the method a practical computing proposition the theory is outlined in sections 2 5 section 6 deals with the solution of the linear equation and section 7 with the resultant forces on the wing some examples are worked out in section 8 to compare with other methods one solution is given in full detail in tables 8 30 as a guide for computers appendices i vi discuss more carefully some salient points of the mathematical theory and appendix vii is intended to instruct the computer how to carry out the steps of the calculation
CRAN	the effect of end plates on swept wings the effect of end plates on swept wings existing methods of calculating the effect of endplates on straight wings are modified so as to apply to swept wings the changes in overall lift and drag and also the spanwise distribution of the additional load can be calculated the theoretical results are compared with experimental results obtained on swept wings including new measurements of lift drag and pitching moment made on an untapered the method of calculation is also extended to cover the effect of the tip vortex which is formed on wings without endplates
CRAN	low speed tests on 45 sweptback wings low speed tests on 45 sweptback wings this report contains the results of pressure measurements on three and aspect ratio 5 over an incidence range up to 10 chordwise and spanwise lift distributions are given mostly near the centre where on two of the wings modifications had been made to the section shape it was found that altering the thickness distribution in the centre did not affect the loading but that approximately straight isobars could be obtained at values of below about 0 1 by the incorporation of twist and camber in the central part the distortion of the lift distribution in the centre could be avoided at one particular incidence and thus the same chordwise distribution obtained over most of the span twist and camber alone do not improve the isobar pattern and therefore a thickness modification would be needed to give the desired lift distribution and isobar pattern at one particular incidence the results of experimental investigations of the boundary layer and of the effect of aspect ratio will be given in a later report
CRAN	generalized conical flow fields in supersonic wing theory generalized conical flow fields in supersonic wing theory linearized compressible flow analysis is applied to the study of quasi conical supersonic wing theory single integral equations are derived which relate either the loading to the shape of a lifting surface or the thickness of a symmetrical wing to the pressure distribution for triangular wings with subsonic leading edges the forms of these equations and their inversions are simplified through the introduction of the finite part and the generalized principal part of an integral applications of the theory in the lifting case include previously known results in the nonlifting case it is shown that for a specified pressure distribution the theory does not always predict a unique thickness distribution this is demonstrated for a triangular plan form having a constant pressure gradient in the stream direction
CRAN	integrals and integral equations in linearized wing theory integrals and integral equations in linearized wing theory the formulas of subsonic and supersonic wing theory for source doublet and vortex distributions are reviewed and a systematic presentation is provided which relates these distributions to the pressure and to the vertical induced velocity in the plane of the wing it is shown that care must be used in treating the singularities involved in the analysis and that the order of integration is not always reversible concepts suggested by the irreversibility of order of integration are shown to be useful in the inversion of singular integral equations when operational techniques are used a number of examples are given to illustrate the methods presented attention being directed to supersonic flight speeds
CRAN	the lift of twisted and cambered wings in supersonic flow the lift of twisted and cambered wings in supersonic flow a generalised conical flow theory is used to deduce an integral equation relating the velocity potential on a delta wing with subsonic leading edges to the given downwash distribution over the wing the complete solution of this integral equation is derived this complete solution is composed of two parts one being symmetric and the other antisymmetric with respect to the spanwise co ordinate each part represents a velocity potential for example if y is the spanwise co ordinate and x is measured in the free stream direction then a downwash of the form w a ux y is symmetric and will give rise to a symmetric potential whereas w a ux y sgn y is anti symmetric and gives rise to an anti symmetric potential the velocity potentials of such flows are given in the form of tables for all downwashes up to and including homogenous cubics in the spanwise and streamwise co ordinates table iii gives similar formulae in the limiting case were used over a cycle of the tumbling motion the analytical expression was in good agreement with numerical solutions of the complete non linear equations of motion
CRAN	the use of conical camber to produce flow attachment at the leading edge of a delta wing and to minimize the lift dependent drag at sonic and supersonic speeds the use of conical camber to produce flow attachment at the leading edge of a delta wing and to minimize the lift dependent drag at sonic and supersonic speeds in an attempt to avoid flow separation at the leading edge of a thin delta wing with subsonic leading edges an attachment line is prescribed there this is done by requiring the load as predicted by attached flow theory to vanish along the leading edge at the design lift coefficient for sonic speed a complete account of this flow is given in terms of slender wing theory and the load distributions corresponding to arbitrary conical camber are calculated for supersonic speeds load distributions arising in the slender wing theory are considered and the corresponding conical camber distributions are found by linearized theory the lift dependent drag for a given lift is then minimized with respect to the coefficients of a linear combination of these load distributions it is found that the lift dependent drag factor for these conically cambered wings approaches the value it takes for the attached flow in which leading edge suction occurs past the uncambered wing at the same mach number as more terms are included in the linear combination however when the leading edge is almost sonic an appreciable reduction is predicted the corresponding load distributions and wing shapes are calculated and drawn the optimum shapes for a fixed number of terms resemble flat plates drooped downwards near their edges so that the localised leading edge suction is replaced by a distributed force on a forward facing surface producing an effect of similar magnitude
CRAN	tables of complete elliptic integrals tables of complete elliptic integrals the present paper contains a set of tables of complete elliptic integrals computed and collected especially for applications to certain dynamical problems the tabulated functions are four in number and are denoted by f a g a e a and a b respectively the definitions of these functions and their connections with the functions of legendre will be discussed in the following
CRAN	aerodynamic effects of some configuration variables on the aeroelastic characteristics of lifting surfaces at mach numbers from 0 7 to 6 86 aerodynamic effects of some configuration variables on the aeroelastic characteristics of lifting surfaces at mach numbers from 0 7 to 6 86 results of flutter tests on some simple all movable control type models are given one set of models which had a square planform with double wedge airfoils with four different values of leading  and trailing edge radii from 0 to 6 percent chord and airfoil thicknesses of 9 11 at mach numbers from 0 7 to 6 86 the bending to torsion frequency ratio was about 0 33 the other set of models which had a tapered planform with single wedge and double wedge airfoils with thicknesses of 3 6 9 and 12 percent chord was tested at mach numbers from 0 7 to 3 98 and a frequency ratio of about 0 42 the tests indicate that in general increasing thickness has a destabilizing effect at the higher mach numbers but is stabilizing at subsonic and transonic mach numbers double wedge airfoils are more prone to flutter than single wedge airfoils at comparable stiffness levels increasing airfoil bluntness has a stabilizing effect on the flutter boundary at supersonic speeds but has a negligible effect at subsonic speeds however increasing bluntness may also lead to divergence at supersonic speeds results of calculations using second order piston theory aerodynamics in conjunction with a coupled mode analysis and an uncoupled mode analysis are compared with the experimental results for the sharp edge airfoils at supersonic speeds the uncoupled mode analysis more accurately predicted the flutter characteristics of the tapered planform models whereas the coupled mode analysis was somewhat better for the square planform models for both the uncoupled  and coupled mode analyses agreement with the experimental results improved with increasing mach number in general both methods of analysis gave unconservative results with respect to the experimental flutter boundaries
CRAN	flutter tests of some simple models at a mach number of 7 2 in helium flow flutter tests of some simple models at a mach number of 7 2 in helium flow results of hypersonic flutter tests on some simple models are presented the models had rectangular plan forms of panel aspect ratio 1 0 no sweepback and bending to torsion frequency ratios of about two airfoil sections were included in the tests double wedges of 5  10  and 15 percent thickness and flat plates with straight parallel sides and beveled leading and trailing edges the models were supported by a cantilevered shaft the double wedge wings were tested in helium at a mach number of 7 2 an effect of airfoil thickness on flutter speed was found thicker wings requiring more stiffness to avoid flutter a few tests in air at a mach number of 6 9 showed the same thickness effect and also indicated that tests in helium would predict conservative flutter boundaries in air the data in air and helium seemed to be correlated by piston theory calculations piston theory calculations agreed well with experiment for the thinner models but began to deviate as the thickness parameter approached and exceeded 1 0 a few tests on flat plate models with various elastic axis locations were made piston theory calculations would not satisfactorily predict the flutter of these models probably because of their blunt leading edges
CRAN	oscillating airfoils at high mach number oscillating airfoils at high mach number a simple formula is given for the pressure distribution on an oscillating airfoil in two dimensional flow at high mach number the formula is expected to be reasonably accurate if the pressure on the surface remains within the range 0 2 to 3 5 times the mainstream pressure to illustrate the application of the formula some results for symmetrical airfoils performing pitching oscillations are obtained and compared with results obtained from existing theories in the case of high mach number
CRAN	tables of aerodynamic coefficients obtained from developed newtonian expressions for complete and partial conic and spheric bodies at combined angles of attack and sideslip with some comparisons with hypersonic experimental data tables of aerodynamic coefficients obtained from developed newtonian expressions for complete and partial conic and spheric bodies at combined angles of attack and sideslip with some comparisons with hypersonic experimental data closed form expressions and tables composed from these expressions are presented for complete and partial conic and spheric bodies at combined angles of attack and sideslip in newtonian flow aerodynamic coefficients of these bodies are tabulated for various body segments over a range of angles of attack from 1degree to 85degree and angles of sideslip from 0degree to 15degree some comparisons between newtonian predictions and hypersonic experimental aerodynamic characteristics were made for conic bodies having various surface slopes nose bluntnesses and body cross sections to indicate the range of validity of the theory in general the theory is shown to agree quite well with experimental results for sharp nose complete cones and for configurations having large blunted noses and steep surface slopes however agreement between theory and experiment generally is poor for the more slender slightly blunted complete or half conic bodies and also for sharp nose half conic bodies where real flow phenomena such as forebody interference viscous forces leeward surface contributions or leading edge pressure reductions may have significant effect the agreement between theory and experiment for the bodies considered can be improved by using the stagnation pressure coefficient behind a normal shock rather than 2 as the newtonian coefficient although for the sharp nose half conic bodies there is no theoretical justification for this modification
CRAN	investigation of the laminar aerodynamics heat transfer characteristics of a hemisphere cylinder in the langley 11 inch hypersonic tunnel at a mach number of 6 8 investigation of the laminar aerodynamics heat transfer characteristics of a hemisphere cylinder in the langley 11 inch hypersonic tunnel at a mach number of 6 8 a program to investigate the aerodynamic heat transfer of a nonisothermal hemisphere cylinder has been conducted in the langley 11 inch hypersonic tunnel at a mach number of 6 8 and a reynolds number from approximately 0 14x10 to experimental heat transfer coefficients were slightly less over the whole body than those predicted by the theory of stine and wanlass naca technical note 3344 for an isothermal surface for stations within 45 of the stagnation point the heat transfer coefficients could be correlated by a single relation between local stanton number and local reynolds number pitot pressure profiles taken at a mach number of 6 8 on a hemisphere cylinder have verified that the local mach number or velocity outside the boundary layer required in the theories may be computed from the surface pressures by using isentropic flow relations and conditions immediately behind a normal shock the experimental pressure distribution at a mach number of velocity gradients calculated at the stagnation point by using the modified newtonian theory vary with mach number and are in good agreement with those obtained from measured pressures for mach numbers from 1 2 to 6 8 at the stagnation point the theory of sibulkin in which the diameter and conditions behind the normal shock were used was in good agreement with the experiment when the velocity gradient at the stagnation point appropriate to the free stream mach number was used
CRAN	investigaion of the flow over a spiked nose hemisphere cylinder at a mach number of 6 8 investigaion of the flow over a spiked nose hemisphere cylinder at a mach number of 6 8 the shape and nature of the flow over a spiked nose hemisphere cylinder was studied in detail at a nominal mach number of 6 8 and in a reynolds number range based on diameter and stream conditions ahead of the model of 0 12 x 10 to 1 5 x 10 schlieren photographs showed the effect of varying the spike length and reynolds number upon the shape of the separated boundary and upon the location of transition the heat transfer and pressure distribution over the body were then correlated with the location of the start of separation the location of reattachment and the location of the start of transition
CRAN	calculation procedure for thermodynamic transport and flow properties of the combustion products of a hydrocarbon fuel mixture burned in air with results for ethylene air and methane air mixtures calculation procedure for thermodynamic transport and flow properties of the combustion products of a hydrocarbon fuel mixture burned in air with results for ethylene air and methane air mixtures a procedure is presented whereby the composition thermodynamic properties and transport properties of the dissociated combustion products of a fuel consisting of a mixed hydrocarbon compound burned in air may be calculated equations and procedures for determining supersonic nozzle ordinates and flow properties for the dissociated combustion products are presented in an appendix results are presented for the respective hydrocarbon fuels methane and ethylene at the equivalence ratios of 1 0 0 9 0 8 and 0 7 for pressures varying between 10 and 8 x 10 atmospheres and temperatures from 200degree k to
CRAN	investigation of the jet effects on a flat surface downstream of the exit of a simulated turbojet nacelle at a free stream mach number of 2 02 investigation of the jet effects on a flat surface downstream of the exit of a simulated turbojet nacelle at a free stream mach number of 2 02 an investigation at a free stream mach number of 2 02 was made to determine the effects of a propulsive jet on a wing surface located in the vicinity of a choked convergent nozzle static pressure surveys were made on a flat surface that was located in the vicinity of the propulsive jet the nozzle was operated over a range of exit pressure ratios at different fixed vertical distances from the flat surface within the scope of this investigation it was found that shock waves formed in the external flow because of the presence of the propulsive jet impinged on the flat surface and greatly altered the pressure distribution an integration of this pressure distribution with the location of the propulsive jet exit varied from 1 450 propulsive jet exit diameters to 3 392 propulsive jet exit diameters below the wing resulted in an incremental lift for all jet locations that was equal to the gross thrust at an exit pressure ratio of 2 86 this incremental lift increased with increase in exit pressure ratio but not so rapidly as the thrust increased and was approximately constant at any given exit pressure ratio
CRAN	investigation of jet effects on a flat surface downstream of the exit of a simulated turbojet nacelle at a free stream mach number of 1 39 investigation of jet effects on a flat surface downstream of the exit of a simulated turbojet nacelle at a free stream mach number of 1 39 an investigation at a free stream mach number of 1 39 utilizing a blowdown type tunnel was made to determine the effects of a propulsive jet on a zero angle of attack wing surface located in the vicinity of both a choked convergent nozzle and a convergent divergent nozzle staticpressure surveys were made on a flat surface that was located in the vicinity of the propulsive jet the nozzles were operated over a varied range of both exit static  and total pressure ratios at different within the scope of this investigation it was found that shock waves formed in the external flow because of the presence of the jet exhaust impinged on the flat surface and greatly altered the pressure distribution an integration of this pressure distribution for the choked convergent nozzle with the location of the propulsive jet exit varied from 1 747 jet exit diameters to 4 981 jet exit diameters below the wing surface resulted in a positive incremental normal force on the wing at all positions
CRAN	pressure distribution induced on a flat plate by a supersonic and sonic jet exhaust at a free stream mach number of 1 80 pressure distribution induced on a flat plate by a supersonic and sonic jet exhaust at a free stream mach number of 1 80 as a continuation of previous research at mach numbers of 2 02 and 1 39 an experimental investigation was made of the pressures induced on a flat plate by a propulsive jet exhausting from sonic and supersonic nozzles at a free stream mach number of 1 80 measurements of the pressure distribution on a flat plate wing were made at zero angle of attack for four different locations of the jet exhaust nozzle beneath the wing both a choked convergent nozzle and a convergent divergent nozzle on the nacelle were used the nozzles were operated at nacelle exit total pressure ratios from 2 to 16 and the reynolds number per foot was approximately 13 x 10 two distinct shock waves impinged on the wing surface and greatly altered the pressure distribution at all nozzle positions positive incremental normal force resulted on the wing at all positions comparisons are presented for two free stream mach numbers
CRAN	some experiments relating to the problem of simulation of hot jet engines in studies of jet effects on adjacent surfaces at a free stream mach number of 1 80 some experiments relating to the problem of simulation of hot jet engines in studies of jet effects on adjacent surfaces at a free stream mach number of 1 80 an investigation at a free stream mach number of 1 80 in a blowdown type tunnel was made to study the effect on the pressure distribution of a zero angle of attack wing surface when certain exhaust parameters of a hot turbojet engine are varied static pressure surveys were made on a wing surface that was located in the vicinity of a small scale propulsive jet this propulsive jet was operated with four types of jet exhausts these jet exhausts were a hot jet hydrogen burned in air a cold air jet a cold helium jet and a jet composed of a mixture of two cold gases hydrogen and carbon dioxide the hot jet because of its high exhaust temperature 3 300degreer and because combustion was performed in air was believed reasonably able to simulate the exhaust parameters of an actual afterburning turbojet engine the cold jets used were selected in order that the effects of a variation in the exhaust parameters of jet exit static pressure ratio ratio of specific heats density and velocity could be obtained by comparing each cold jet with the hot jet or with another cold jet the tests were made over a range of jet exit staticpressure ratios from 1 to 9 with values of the ratio of specific heats of 1 27 1 40 and 1 66 and at variations in density and velocity of the order of approximately 8 and 3 times respectively within the scope of this investigation it was found that jet exit static pressure ratio and the ratio of specific heats affected the pressure distribution on the wing associated with jet interference while a variation in exit velocity and density did not the jet exit staticpressure ratio affected the wing pressure distribution in a major way while the ratio of specific heats had only a minor effect the addition of temperature in the propulsive jet exhaust at a jet exit staticpressure ratio of 4 had little or no effect on the pressure distribution associated with jet interference on the wing
CRAN	pressure loads produced on a flat plate wing by rocket jets exhausting in a spanwise direction below the wing and perpendicular to a free stream flow of mach number 2 0 pressure loads produced on a flat plate wing by rocket jets exhausting in a spanwise direction below the wing and perpendicular to a free stream flow of mach number 2 0 an investigation at a reynolds number per foot of 14 4 x 10 was made to determine the pressure loads produced on a flat plate wing by rocket jets exhausting in a spanwise direction beneath the wing and perpendicular to a free stream flow of mach number 2 0 the ranges of the variables involved were 1 nozzle types   one sonic jet mach number of two dimensional supersonic jet mach number of 1 71 2 vertical nozzle positions beneath the wing of 4 8 and 12 nozzle throat diameters and 3 ratios of rocket chamber total pressure to free stream static pressure from 0 to 130 the incremental normal force due to jet interference on the wing varied from one to two times the rocket thrust and generally decreased as the pressure ratio increased the chordwise coordinate of the incremental normal force center of pressure remained upstream of the nozzle center line for the nozzle positions and pressure ratios of the investigation the chordwise coordinate approached zero as the jet vertical distance beneath the wing increased in the spanwise direction there was little change due to varying rocket jet position and pressure ratio some boundary layer flow separation on the wing was observed for the rocket jets close to the wing and at the higher pressure ratios the magnitude of the chordwise and spanwise pressure distributions due to jet interference was greatest for rocket jets close to the wing and decreased as the jet was displaced farther from the wing the design procedure for the rockets used is given in the appendix
CRAN	effects on adjacent surfaces from the firing of rocket jets effects on adjacent surfaces from the firing of rocket jets this paper is a preliminary and brief account of some research currently being conducted to determine the jet effects on adjacent surfaces from the firing of rocket jets measurements of jet effect pressures on a flat plate as well as shadowgraphs are presented that were obtained when a rocket jet at a mach number of 3 was exhausted downstream and upstream into free stream flow at a mach number of 2 located from 2 to 4 7 rocket jet exit diameters from the plate the jet effects on the flat plate with the rocket jet exhausting downstream are of the same order of magnitude as those previously obtained from sonic exits with a total pressure 10 times lower a maximum pressure coefficient on the plate of rocket jet exit diameters below the plate and an integration of the measured jet effect pressures at this position resulted in a normal force on the plate equal to 2 3 times the thrust output of the rocket jet
CRAN	the unsteady lift of a wing of finite aspect ratio the unsteady lift of a wing of finite aspect ratio unsteady lift functions for wings of finite aspect ratio have been calculated by correcting the aerodynamic inertia and the angle of attack of the infinite wing the calculations are based on the operational method the starting lift of the finite wing is found to be only slightly less than that of the infinite wing whereas the final lift may be considerably less the theory indicates that the initial distribution of lift is similar to the final distribution curves showing the variation of lift after a sudden unit change in angle of attack during penetration of a sharpedge gust and during a continuous oscillation are given operational equivalents of these functions have been devised to facilitate the calculation of lift under various conditions of motion as an application of these formulas the vertical acceleration of a loaded wing caused by penetrating a gust has been calculated
CRAN	approximate indical lift functions for several wings of finite span in incompressible flow as obtained from oscillatory lift coefficients approximate indical lift functions for several wings of finite span in incompressible flow as obtained from oscillatory lift coefficients the unsteady lift functions for a wing undergoing a sudden change in sinking speed have been presented for delta wings having aspect ratios of 0 2 and 4 and for rectangular and elliptical wings having aspect ratios of 0 3 and 6 for the elliptical and rectangular wings the spanwise lift distributions were also presented these functions were calculated from the lift coefficients associated with a wing oscillating harmonically in pure translational motion as obtained from several sources the results of these calculations indicate that the normalized unsteady lift functions are substantially independent of the shape of the plan form for elliptical rectangular or moderately tapered wings however for delta wings the increase of lift toward the steady state value is much more rapid than that for the aforementioned wings of the same aspect ratio these results also corroborate the results of other investigations in that the rate of growth of lift tends to increase with a decrease in aspect ratio the shape of the spanwise distributions of the indicial lift seems to be for all practical purposes independent of time for rectangular and elliptical wings
CRAN	two and three dimensional unsteady lift problems in high speed flight two and three dimensional unsteady lift problems in high speed flight the problem of transient lift on two  and three dimensional wings flying at high speeds is discussed as a boundary value problem for the classical wave equation kirchhoffs formula is applied so that the analysis is reduced just as in the steady state to an investigation of sources and doublets the applications include the evaluation of indicial lift and pitchingmoment curves for two dimensional sinking and pitching wings flying at mach numbers equal to 0 0 8 1 0 1 2 and triangular wings in both forward and reversed flow are presented and compared with the two dimensional values
CRAN	numerical determination of indical lift of a two dimensional sinking airfoil at subsonic mach numbers from oscillatory lift coefficients with calculations for mach number 0 7 numerical determination of indical lift of a two dimensional sinking airfoil at subsonic mach numbers from oscillatory lift coefficients with calculations for mach number 0 7 the reciprocal equations for relating the incompressible circulatory indicial lift to the lift due to harmonic oscillations have been modified to include the noncirculatory lift associated with apparent mass effects although the apparent mass effects are impulsive in nature in incompressible flow the lift due to apparent mass effects in compressible flow is a time dependent function the corresponding reciprocal equations for the total compressible lift are given by use of the reciprocal equations for compressible flow the indicial lift and moment functions due to an airfoils experiencing a sudden acquisition of vertical velocity are determined numerically for mach number 0 7 lack of sufficient flutter coefficients prevents the calculation of these functions at other mach numbers although the indicial lift and moment functions due to penetration of a sharp edge gust may be obtained from the oscillatory tab or aileron coefficients by a similar analysis sufficient coefficients are not available at the present however an approximate method is shown for determining a portion of this unsteady lift function when a comparison is made of the indicial lift functions at mach numbers appears to be less rapid for the compressible case than for the incompressible case consequently the calculation of the gust load factor at high subsonic mach numbers utilizing the two dimensional incompressible indicial lift functions and an over all correction for compressibility such as the prandtl glauert factor might be conservative
CRAN	numerical determination of indical lift and moment functions for a two dimensional sinking and pitching airfoil at mach numbers 0 5 and 0 6 numerical determination of indical lift and moment functions for a two dimensional sinking and pitching airfoil at mach numbers 0 5 and 0 6 the indicial lift and moment functions are determined approximately for sinking and pitching motion at mach numbers m of 0 5 and 0 6 these functions are determined from a knowledge of the existing oscillatory coefficients at the low reduced frequencies and from approximate expressions of these coefficients at the high reduced frequencies the beginning portion of the indicial lift function associated with an airfoil penetrating a sharp edge gust in subsonic flow is evaluated by use of an exact method by use of an approximate method for determining the remaining portion the complete indicial gust function is determined for m 0 5 m 0 6 and m 0 7 all the indicial lift and moment functions are approximated by an exponential series the coefficients which appear in the exponential approximations for each indicial function are tabulated for m 0 5 m 0 6 and m 0 7
CRAN	general airfoil theory general airfoil theory on the assumption of infinitely small disturbances the author develops a generalized integral equation of airfoil theory which is applicable to any motion and compressible fluid successive specializations yield various simpler integral equations such as possios birnbaums and prandtls integral equations as well as new ones for the wing of infinite span with periodic downwash distribution and for the oscillating wing with high aspect ratio lastly several solutions and methods for solving these integral equations are given
CRAN	a systematic kernel function procedure for determining aerodynamic forces on oscillating or steady finite wings at subsonic speeds a systematic kernel function procedure for determining aerodynamic forces on oscillating or steady finite wings at subsonic speeds a detailed description is given of a method of approximating solutions to the integral equation that relates oscillatory or steady lift and downwash distributions on finite wings in subsonic flow the method of solution is applicable to general plan forms with either curved or straight leading and trailing edges moreover it is directly applicable to control surfaces such as all movable tails but modifications are needed to apply it to controls in general applications of the method involve evaluations of numerous integrals that must be handled by numerical procedures but systematic schemes of evaluations have been adopted that are well suited to the routines of automatic digital computing machines these schemes of evaluation have been incorporated in a program for an ibm 704 electronic data processing machine with this machine a pressure distribution together with such quantities as section or total lift and moment coefficients or generalized forces can be determined for a given value of frequency and mach number and for several four or five modes of oscillation in about 4 minutes of machine time in the case of steady downwash conditions corresponding quantities can be obtained in about 2 minutes of machine time in order to illustrate applications of the method results of several calculations are presented in these illustrations total forces and moments are compared 1 with results of analytic procedures for a circular plan form with steady downwash conditions 2 with results of other theories and with experiment for a rectangular plan form of aspect ratio 1 at a uniform angle of attack and 3 with some experimental results for a rectangular plan form of aspect ratio 2 undergoing pitching and flapping oscillations also included in the illustrations are results of flutter calculations compared with experimental results for an allmovable control surface of aspect ratio 3 50 and for a cantilevered rectangular plan form of aspect ratio 5 04
CRAN	on the kernel function of the integral equation relating the lift and downwash distributions of oscillating finite wings in subsonic flow on the kernel function of the integral equation relating the lift and downwash distributions of oscillating finite wings in subsonic flow this report treats the kernel function of an integral equation that relates a known or prescribed downwash distribution to an unknown lift distribution for a harmonically oscillating finite wing in compressible subsonic flow the kernel function is reduced to a form that can be accurately evaluated by separating the kernel function into two parts a part in which the singularities are isolated and analytically expressed and a nonsingular part which may be tabulated the form of the kernel function for the sonic case mach number of 1 is treated separately in addition results for the special cases of mach number of o incompressible case and frequency of o steady case are given the derivation of the integral equation which involves this kernel function originally performed elsewhere see for example naca technical memorandum 979 is reproduced as an appendix another appendix gives the reduction of the form of the kernel function obtained herein for the three dimensional case to a known result of possio for two dimensional flow a third appendix contains some remarks on the evaluation of the kernel function and a fourth appendix presents an alternate form of expression for the kernel function
CRAN	on som reciprocal relations in the theory of nonstationary flows on som reciprocal relations in the theory of nonstationary flows in the theory of nonstationary flows about airfoils the indicial lift function k s of wagner and the alternating lift function c k of theodorsen have fundamental significance this paper reports on some interesting relations of the nature of fourier transforms that exist between these functions general problems in transient flows about airfoils may be given a unified broad treatment when these functions are employed certain approximate results also are reported which are of notable simplicity and an analogy with transient electrical flows is drawn
CRAN	thermal analysis of stagnation regions with emphasis on heat sustaining nose shapes at hypersonic speeds thermal analysis of stagnation regions with emphasis on heat sustaining nose shapes at hypersonic speeds the leading edges and noses of hypersonic vehicles are subjected to severe aerodynamic heating and must be cooled in some manner dash e g internal convection transpiration or radiation it is this latter mode of handling the problem that is discussed in this paper neglecting conduction in the leading edge region the maximum temperature for long range hypersonic gliders is of the same order as the melting point of refractory materials with a corresponding large temperature gradient away from the leading edge inclusion of conduction in the aft direction reduces the maximum temperature and distributes the heat to a location that will radiate it out from the surface for either steady state or transient conditions the temperature at the leading edge is reduced by conduction while the temperature aft of the leading edge shoulder is increased thus setting up a heat transmission balance between the convective influx of heat the redistribution of heat by conduction and the radiation of heat from the surface the feasibility of such a mechanism can be enhanced by suitably choosing leading edge shapes and materials the philosophy behind the choice of leading edge shapes is discussed and the effects of varying parameters such as shape diameter emissivity conductivity thickness etc are shown
CRAN	aerodynamic characteristics of two winged reentry vehicles at supersonic and hypersonic speeds aerodynamic characteristics of two winged reentry vehicles at supersonic and hypersonic speeds tests were conducted at the langley research center on two winged lifting hypersonic reentry glider configurations performance stability and control data are presented at mach numbers of 1 62 and 2 91 for angles of attack up to 15degree and at mach numbers of 6 8 and 9 6 for angles of attack up to 25degree
CRAN	static longitudinal aerodynamic characteristics at transonic speeds and angles of attack up to 99degree of a reentry glider having folding wingtip panels static longitudinal aerodynamic characteristics at transonic speeds and angles of attack up to 99degree of a reentry glider having folding wingtip panels data are presented which were obtained from a transonic wind tunnel investigation of a reentry glider having folding wing tip panels the tests were conducted at angles of attack from  4degrees to 99degrees the reynolds number based on the mean geometric chord of the fixed planform varied from 2 35 x 10 to 2 99 x 10 the maximum lift drag ratio for the model with the folding wing tip panels fully extended decreased from a maximum value of 7 8 at a mach number of 0 60 to about 3 4 at mach numbers from 1 03 to 1 20 the model with the folding wing panels fully extended was stable for values of the lift coefficient from 0 up to at least 0 8 above this lift coefficient pitch up tendencies were observed followed by an unstable or neutrally stable region which extended up to values of angle of attack of 50degrees or 60degrees deflecting the folding wing panels between ducing a significant change in the trim angle of attack or in any of the force or moment coefficients in the angle of attack range from 49degree to 99degree
CRAN	the smallest height of roughness capable of affecting boundary layer transition the smallest height of roughness capable of affecting boundary layer transition an investigation was made to determine the smallest size of isolated roughness that will affect transition in a laminar boundary layer critical heights for three types of roughness were found in a low speed wind tunnel the types were 1 two dimensional spanwise wires 2 three dimensional discs and 3 a sandpaper type in addition to type of roughness test variables included the location of roughness pressure distribution degree of tunnel turbulence and length of natural laminar flow the most satisfactory correlation parameter was found to be the roughness reynolds number based on the height of roughness and flow properties at this height the value of this critical reynolds number was found to be substantially independent of all test variables except the shape of roughness this parameter also correlates well other published data on critical roughness in low speed flow the value of the roughness reynolds number necessary to move transition forward to the roughness itself was also determined for the three types of roughness and was found to be approximately constant for a given type of roughness an investigation of the limited amount of available data on critical roughness in supersonic flow indicates that the effects of roughness may still be correlated by the roughness reynolds number the value of this reynolds number depends primarily on the mach number at the top of the roughness when this mach number is greater than 1 0 the roughness reynolds number based on conditions behind a shock is probably the characteristic parameter
CRAN	an investigation at subsonic speeds of aerodynamic characteristics at angles of attack from  dash 4degrees to 100degrees of a delta wing reentry configuration having folding wingtip panels an investigation at subsonic speeds of aerodynamic characteristics at angles of attack from  dash 4degrees to 100degrees of a delta wing reentry configuration having folding wingtip panels an investigation was made at subsonic speeds in the langley highspeed lifting reentry configuration having folding wingtip panels the configuration is of the type used in a high angle of attack near 90degree reentry to minimize aerodynamic heating by unfolding the wingtip panels into the airstream a moderate angle of attack glide is used for a controlled landing the basic configuration tested utilized a whose area was 25 percent of the total wing area the effects of varying the plan form and size of the wingtip panels was studied as well as the effects of unfolding the wingtip panels in a high angle  of attack attitude tests were made at mach numbers of 0 40 0 60 and
CRAN	low speed longitudinal aerodynamic characteristics associated with a series of low aspect ratio wings having variations in leading edge contour low speed longitudinal aerodynamic characteristics associated with a series of low aspect ratio wings having variations in leading edge contour an investigation has been conducted at various reynolds numbers and low subsonic speeds to determine the longitudinal aerodynamic characteristics associated with a series of low aspect ratio wings having variations in leading edge contours the planforms included a highly swept triangular wing a rectangular wing and intermediate wings including planforms having elliptic and parabolic leading edge contours all having an aspect ratio of 1 33 the effects of changing aspect ratio for a given leading edge contour were investigated for two of the wings presented also included are the longitudinal characteristics associated with various fuselage sizes an effort has been made to estimate the lift variation with angle of attack for the wing planforms of the present investigation improvements in the lifting capabilities at low subsonic speeds associated with a basic triangular planform of low aspect ratio are possible by slight alterations in leading edge design which should still conform to possible design requirements at hypersonic speeds these changes in planform resulted in increases in lift curve slope lift at high angles of attack and in the maximum untrimmed lift drag ratio provided the fuselage was sufficiently small the longitudinal stability characteristics of the majority of planforms indicate more desirable stability characteristics at high lifts than either a triangular wing or rectangular wing of the same aspect ratio the effects of increasing reynolds number for each of the planforms investigated generally resulted in slight reductions in the lift at high angles of attack a method is presented for estimating the subsonic lift variation with angle of attack for the low aspect ratio wings of the present investigation and indicated good agreement with experimental data throughout the angle of attack range of this investigation
CRAN	static longitudinal stability characteristics of a blunted glider re entry configuration having 79 5degree sweepback and 45degree dihedral at a mach number of 6 2 and angles of attack up to 20degree static longitudinal stability characteristics of a blunted glider re entry configuration having 79 5degree sweepback and 45degree dihedral at a mach number of 6 2 and angles of attack up to 20degree an experimental investigation was conducted at a mach number of 6 2 to determine the static longitudinal stability characteristics of a model of a blunted glider reentry configuration having 79 5degree sweepback and 45degree dihedral the free stream reynolds number for the investigation was 3 0 x 10 based on the basic model length of 7 5 inches tests were made through an angle of attack range from 0degrees to investigation showed that incorporating 10degree nose incidence in the basic model resulted in a lower lift curve slope a lower lift drag ratio a higher value of trim lift coefficient and a decrease in static longitudinal stability in comparison the effect of extending the configuration length and incorporating 10degrees and 20degrees boattail angles resulted in smaller changes in the longitudinal stability characteristics of the model
CRAN	blockage corrections for three dimensional flow closed throat wind tunnels with considerations of the effect of compressibility blockage corrections for three dimensional flow closed throat wind tunnels with considerations of the effect of compressibility theoretical blockage corrections are presented for a body of revolution and for a three dimensional unswept wing in a circular or rectangular wind tunnel the theory takes account of the effects of the wake and of the compressibility of the fluid and is based on the assumption that the dimensions of the model are small in comparison with those of the tunnel throat formulas are given for correcting a number of the quantities such as dynamic pressure and mach number measured in wind tunnel tests the report presents a summary and unification of the existing literature on the subject
CRAN	motion of a ballistic missile angularly misaligned with the flight path upon entering the atmosphere and its effect upon aerodynamic heating aerodynamic loads and miss distance motion of a ballistic missile angularly misaligned with the flight path upon entering the atmosphere and its effect upon aerodynamic heating aerodynamic loads and miss distance an analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path the history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading the miss distance at the target due to misalignment and to small accidental trim angles is treated the stability problem is also discussed for the case where the missile is tumbling prior to atmospheric entry
CRAN	study of the oscillatory motion of manned vehicles entering the earths atmosphere study of the oscillatory motion of manned vehicles entering the earths atmosphere an analysis is made of the oscillatory motion of vehicles which traverse arbitrarily prescribed trajectories through the atmosphere expressions for the oscillatory motion are derived as continuous functions of the properties of the trajectory results are applied to a study of the oscillatory behavior of re entry vehicles which have decelerations that remain within limits of human tolerance it is found that a deficiency of aerodynamic damping for such vehicles may have more serious consequences than it does for comparable ballistic missiles
CRAN	motions of a short 10degree blunted cone entering a martian atmosphere at arbitrary angles of attack and arbitrary pitching rates motions of a short 10degree blunted cone entering a martian atmosphere at arbitrary angles of attack and arbitrary pitching rates the dynamic behavior of two probe vehicles entering a martian atmosphere in a passive manner with arbitrary initial angles of attack and pitching rates to 12degree per second has been determined results for an entry velocity of 21 700 feet per second and an entry angle of  40degree were obtained from machine calculated solutions of the six degree  of freedom rigid body equations of motion using experimental aerodynamic characteristics for the vehicles one of the vehicles had a flat base and was statically stable in two attitudes nose forward and base forward the other vehicle derived from the first by adding a conical afterbody was statically stable in only one attitude nose forward a 10 rpm vehicle spin rate believed ample for the purpose of distributing solar and aerodynamic heating over the vehicle surface and model atmospheres encompassing the probable extremes for the planet were also considered it was found that while the motion of the flat based vehicle could be oscillatory about either the nose forward or base forward stable trim attitudes when aerodynamic heating rates were high the range of initial angles of attack resulting in base forward orientation was reduced by more than a factor of 3 when initial pitch rates were increased from body having only nose forward stability showed that oscillatory angles of attack at maximum heating rate conditions probably would not exceed about 25degrees although angles of attack when heating rates were 50 percent of maximum could be as high as 40degree values of these upper bound angles of attack were essentially independent of initial pitch rates for the range considered furthermore the envelope of maximum probable angles of attack was increased only slightly when the vehicle was given a 10 rpm spin rate the relationship between maximum amplitudes of oscillation and heating rates through high heating portions of the trajectories was preserved when model atmospheres believed to encompass the extreme possibilities for mars were used in the calculations
CRAN	means and examples of aeronautical research in france at onera means and examples of aeronautical research in france at onera cosmonautics is currently very much to the forefront in the news it embraces and extends aeronautics and i would like to propose including both at least on certain occasions under a general denomination of aerocosmonautics in your country the sciences and technology of space are subjects which have been backed by initial advances and abundantly treated since france has not yet launched any artificial satellite or built any circumlunar space vehicle i propose to confine myself here to the field of aeronautics where there is still so much progress of manifest utility to accomplish i shall accordingly content myself with presenting some examples of aeronautical research and experiments undertaken in my country by onera a body whose mission is akin to that of the illustrious naca now nasa but bearing in mind the considerable difference between the scales of the respective resources
CRAN	tumbling bodies entering the atmosphere tumbling bodies entering the atmosphere the equations of motion of a tumbling flat plate entering an exponential atmosphere were linearized and solved analytically to obtain a simple expression for the altitude at which tumbling would cease and libration would commence the plate had only three degrees of freedom and aerodynamic forces were derived from newtonian impact theory in the linear analysis mean values of the drag and pitch damping coefficients so that flutter occurs in the range of a low speed wind tunnel a particular type of construction for supersonic flutter models is described in detail methods of vibration testing static testing and flutter testing are discussed particular emphasis is placed on the technique of varying flow parameters rather than model parameters to precipitate flutter the tool for varying flow parameters is the variable mach number supersonic test section of the massachusetts institute of technology blowdown wind tunnel the aerodynamic features of the supersonic test section are presented
CRAN	a note on the use of sandwich structures in severe acoustic environments a note on the use of sandwich structures in severe acoustic environments this paper reviews some of the experience to date of using sandwich type structures in severe acoustic pressure environments the methods used for testing sandwich structures for acoustic fatigue are described and their limitations considered experimental and theoretical work relating to the damping and mode frequency relationships of certain sandwich configurations is also reviewed special attention is given to the estimation of the stress in the bond of a honeycomb sandwich panel subjected to sudden pressure fluctuations a uni modal theory is presented relating the mean square bond stress to the random exciting pressure and panel dynamic characteristics this theory indicates that tensile bond stresses may be encountered of up to six times the local r m s exciting pressure these must be combined with bending and shear stresses to obtain the principal stresses which precipitate bond fatigue failures finally an outline is given of some of the lines of future research which should lead to the achieving of the maximum possible fatigue resistance from sandwich configurations
CRAN	near noise field of a jet engine exhaust near noise field of a jet engine exhaust aircraft structures located in the near noise field of a jet engine are subjected to extremely high fluctuating pressures that may cause structural fatigue studies of such structures have been limited by lack of knowledge of the loadings involved the acoustic near field produced by the exhaust of a stationary turbojet engine having a high pressure ratio was measured for a single operating condition without afterburning the maximum over all sound pressure without afterburning was found to be about 42 pounds per square foot along the jet boundary in the region immediately downstream of the jet nozzle exit with afterburning the maximum sound pressure was increased by 50 percent the largest sound pressures without afterburning were obtained on a constant percentage band width basis in the frequency range from 350 to 700 cps additional tests were made at a few points to find the effect of jet velocity on near field sound pressures and to determine the difference in value between sound pressure levels at rigid surfaces and corresponding free field values near the jet nozzle over all sound pressures were found to vary as a low power approx unity of the jet velocity over all sound pressure levels considerably greater than the corresponding free field levels were recorded at the surface of a rigid plate placed along the jet boundary the downstream locations of the maximum sound pressure at any given frequency along the jet engine exhaust boundary and the longitudinal turbulent velocity maximum of the same frequency along a small cold air jet at 1 nozzle exit radius from the jet axis were found to be nearly the same when compared on a dimensionless basis also the strouhal number of the corresponding spectra maximums was found to be nearly equal at similar distances downstream in addition to the magnitude and frequency distribution of the acoustic pressures it is necessary to know the cross correlation of the pressure over the surface area cross correlation measurements with microphones were made for a range of jet velocities at locations along the jet and at a distance from the jet free field correlations of the over all sound pressure and of the sound pressure in frequency bands from 100 to 1000 cps were obtained both longitudinally and laterally in addition correlations were obtained with microphones mounted at the surface of a rigid plate that was large compared with the distance over which a positive correlation existed the region of positive correlation was generally found to increase with distance downstream of the engine to 6 5 nozzle exit diameters but remained nearly constant thereafter in general little change in the correlation curves was found as a function of jet velocity or frequency band width the distance from unity correlation to the first zero correlation was greater for lateral than for longitudinal correlations for the same conditions and locations the correlation curves obtained in free space and on the surface of the plate were generally similar the results are interpreted in terms of pressure loads on surfaces
CRAN	random excitation of a tailplane section by jet noise random excitation of a tailplane section by jet noise the response of a section of tailplane structure to both discrete and random noise pressures has been studied in detail initially the specimen was mounted behind a jet engine and the induced strains were analysed with the object of determining both the resonant frequencies and the corresponding modes of vibration during these tests a survey was made of the spectrum and correlation pattern of the jet noise on the surface of the model secondly the specimen was mounted in front of a loudspeaker in an acoustics laboratory and the structural resonances were excited by means of discrete frequency sound the mode shapes were studied in detail with the aid of a stroboscope it is concluded that the tailplane skin on this particular piece of structure only responds to any significant degree in one structural mode although reasonable comparison has been obtained between the random and discrete tests it was not possible to calculate the induced stresses using the observed mode shapes and measured pressure excitation
CRAN	on the fatigue failure of structures due to vibrations excited by random pressure fields on the fatigue failure of structures due to vibrations excited by random pressure fields on the assumption that the forced modes of vibration of a structure subjected to pressure fluctuations random in time and space can be approximated by the composition of the motions of the uncoupled natural modes a general analysis is made using the ideas of vibration theory and spectrum analysis the power spectrum and hence the rms value of any quantity depending linearly upon structural distortions is derived and it involves a quantity called the joint acceptance concerning the spacewise structure of the pressure field and of the geometry of the modes of vibration it is shown how this result may be used on assuming normal randomness to estimate the fatigue life on the hypothesis of cumulative damage
CRAN	structural acoustic proof testing structural acoustic proof testing with the introduction of high powered propulsion systems and paralleling their continued development an accompanying increase in acoustical problems has arisen of these acoustical problems that of acoustical fatigue failures has become paramount in the eyes of the structural engineer aircraft designed to normal strength requirements have been known literally to fall apart under acoustical loading this problem has required much endeavour to produce a solution and considerable structural research based upon results of siren or other testing have proved inadequate this failure to find a satisfactory solution has resulted in the conviction that the final proof of a design can be found only in proof testing proof testing in the acoustic fatigue sense is the testing of a design structure in a simulated acoustical environment for a period of time long enough to assure equality with design life
CRAN	the response of a typical aircraft structure to jet noise the response of a typical aircraft structure to jet noise an analysis is made of experimentally determined mode shapes excited on the rear structure of a modern airliner by jet noise from a pod mounted turbojet engine power spectra of stresses determined from strain gage measurements are obtained and cross correlated extensive measurements were made on skin panels of the fuselage and elevator and limited ones were made on fuselage stringers and frames the skin panel results are compared with theoretical predictions reviewer believes that this paper is of considerable value for those concerned with response of aircraft type structures to jet induced noise
CRAN	on structural fatigue under random loading on structural fatigue under random loading experience has shown that the fluctuating loads induced by a jet may cause fatigue failure of aircraft structural components in order to throw some light on this and similar problems the stress spectrum and the equivalent fatigue stress of an elastic structure subjected to random loading are studied the analysis is simplified by assuming the structure to have only a single degree of freedom and by using the concept of cumulative damage the results being expressed in terms of quantities that can be directly measured as an example a similarity expression for the probable value of the equivalent fatigue stress of a panel subjected to jet buffeting is derived
CRAN	a study of the acoustic fatigue characteristics of some flat and curved aluminium panels exposed to random and discrete noise a study of the acoustic fatigue characteristics of some flat and curved aluminium panels exposed to random and discrete noise a study was made of the fatigue life of simple 2024 t3 aluminum alloy panels measuring 11 by 13 inches and exposed to both discrete frequency noise from a siren and random noise from an air jet noise levels varied from approximately panel variables included thickness edge conditions curvature and static pressure differential no significant differences were noted in the nature of failures experienced for the two types of loadings at a given root mean square stress level the failure times were generally shorter for the random loading than for the discrete frequency loading these differences in failure times were noted to be a function of stress level the larger differences occurring at the lower stress levels increases in time to failure were obtained as a result of increased panel thickness increased panel curvature and particularly for increased static pressure differential across curved panels for the discrete type loading the location of weak points in these simplified structural designs can be satisfactorily accomplished but quantitative predictions of fatigue life are much more difficult
CRAN	free vibrations of continuous skin stringer panels free vibrations of continuous skin stringer panels the determination of the natural frequencies and normal modes of vibration for continuous panels representing more or less typical fuselage skin panel construction for modern airplanes is discussed in this paper are considered a numerical example is presented and analytical results for a particular structural configuration agree favorably with available experimental measurements
CRAN	stresses in continuous skin stiffener panels under random loading stresses in continuous skin stiffener panels under random loading theoretical aspects involved in the prediction of stress levels for continuous skin stiffener panels subjected to a random pressure field are considered in the light of powells general theory for statistical superposition of modal response the choice of structural model is dictated by the prevalence of skin stiffener construction in modern flight vehicle design the present study clearly demonstrates that any truly adequate prediction of stress levels in actual aircraft structures requires a much better representation of structural characteristics than can be provided by single panel idealizations in an example considering fuselage panels exposed to jet engine noise essential agreement is shown with experimental data although better correlation is shown for rms stress than for power spectrum it is shown that reduction of stress level by increasing damping is effective only in the higher frequency range
CRAN	on the bending of a clamped plate on the bending of a clamped plate the present paper contains an application of a recently developed variational method to the boundary value problem of the bending of a clamped plate of arbitrary shape it will be shown that this problem can be linked to the simpler problem of the equilibrium of a membrane by a chain of intermediate problems which can be solved explicitly and in finite form in terms of the membrane problem in the intermediate problems the deflection converges uniformly in the domain of the plate of the clamped plate and the derivatives of all orders of the deflection converge uniformly in every domain completely interior to the plate in the ritz method not even the convergence of the slopes can be guaranteed the method yields numerical results for plates of all shapes for which the membrane problem which we shall call the base problem admits an explicit solution as an example we shall consider a clamped square plate under a uniform load this problem has been the object of numerous investigations some of which are theoretical while others are purely numerical use infinite simple and double series and operate with an infinite number of linear equations and an infinite number of unknowns an inspection of the general formulae derived in the present paper formulae which become simple in numerical applications would show how some of the numerical methods might be rendered rigorous the convergence of higher derivatives is of great practical interest for the approximate computation of the stresses
CRAN	upper and lower bounds for the solution of the first biharmonic boundary value problem upper and lower bounds for the solution of the first biharmonic boundary value problem let w x y be a solution of the boundary value problem where r is a plane domain with the boundary c the authors obtain upper and lower bounds for the value of w at a point in r by a method which is applicable to many other problems if u is a function satisfying the boundary conditions and v is a function satisfying the partial differential equation then the authors obtain by applying greens classical identity and schwarzs inequality a pair of inequalities of the form where together with the function w the authors consider a function the solution of the boundary value problem on c and in analogy with the functions u and v associated with the function w a pair of functions and associated with the function in the expression for derived from greens classical identity appears an unknown line integral containing the values of w and on c but the same line integral appears also in the expressions for to which the above inequalities are applicable in this way the authors obtain two inequalities of the form where b and b respectively are approximate values of in order to improve these bounds one may add to u a linear set of functions and to v a linear set of functions and then minimize h u v in order to determine the coefficients of the best linear combinations if the sequences and are complete in a certain sense defined by the authors the approximations will converge to the value
CRAN	on the analogues relating flexure and extension of flat plates on the analogues relating flexure and extension of flat plates the displacement of a flat plate bent by transverse loading and the extensional or in plane stress are governed by equations of identical form and the boundary conditions have identical form when edge displacements are specified in the flexural edge tractions in the extensional problem so mathematically in these circumstances only a single problem is presented this the first analogue relating flexure and extension is well known a second analogue relating the flexural problem when edge tractions with the extensional problem when edge displacements are specified is believed to have been first propounded in 1941 by introducing two quantities u and v analogous with the components u and v of extensional displacement it permits a treatment of the flexural problem by any method  e g which yields extensional solutions of this second type in this paper both analogues are combined in an inclusive statement covering the perforated multiply connected plates which were discussed in 1948 reasons are stated for believing that two diagram technique is preferable in problems governed by mixed boundary conditions
CRAN	the bending of a sectorial plate the bending of a sectorial plate the problem of evaluating the bending moments existing in a uniformly loaded clamped plate having the form of a sector of a ring is one which arises in connection with the stress analysis of reinforced piston heads and in other design problems in this paper expressions are derived for the bending moments along the edges of such a plate similar problems i e those of the clamped rectangular plate under uniform pressure under a central concentrated load and that of the simply supported sector of a disk under uniform pressure have been discussed by previous authors the general approach used in the foregoing problems is adopted in the present case a considerable reduction in the computational work is achieved however by the use of an integral equation method of solving the boundary condition equations numerical results are obtained for plates of various dimensions and the edge moment distributions are plotted for these cases curves are also plotted which indicate the relationship existing between the maximum bending moments derived for sectorial plates and those previously obtained for clamped rectangular plates of similar size
CRAN	the bending of uniformly loaded clamped plate in the form of a circular sector the bending of uniformly loaded clamped plate in the form of a circular sector the deflexion of a uniformly loaded plate in the form of a semicircle clamped along its boundary is obtained by a method due to weinstein this problem requires the solution of the biharmonic equation where z is given subject to the conditions that w 0 and on the boundary n being the direction of the outward normal the solution is expressed in the form where writing is found by solving in succession two harmonic equations of the forms where z may be zero and where f and have to satisfy certain boundary conditions the constants are then determined to satisfy the boundary condition numerical calculations show that five or six terms of the series give a good approximation to the accurate value as judged by the closeness with which the approximate solution satisfies the boundary condition the procedure to be adopted in the case of the general circular sector and for non uniform loading is indicated briefly the connexion between the deflexion problem and that of plane strain in which the stress function satisfies the equation where and have given values on the boundary is discussed as a preliminary to the further consideration of the latter problem by a method of the same type
CRAN	the bending of uniformly loaded sectorial plates with clamped edges the bending of uniformly loaded sectorial plates with clamped edges this paper analyzes the bending of a sectorial plate clamped on all edges and subjected to uniformly distributed load by using two different methods of superposition on the elementary solution for a uniformly loaded circular plate with a clamped edge
CRAN	the bending of a wedge shaped plate the bending of a wedge shaped plate a general method of solution is given in this paper for the problem of bending of a wedge shaped thin elastic plate with arbitrary boundary conditions on the radial edges in the case of a single load the solution is carried out for a plate with clamped edges and a single load on the bisector radius of the plate stress distribution along the edges is shown and the behavior of the solution near the corner point is discussed for several opening angles of the plate
CRAN	on the analysis of elastic plates of variable thickness on the analysis of elastic plates of variable thickness the extensional and flexural equations governing the elastic behaviour of a plate of variable thickness are expressed in terms of the laplacian operator temperature variations in the plane of the plate and across the thickness of the plate are taken into account general solutions are given for a rectangular plate whose thickness varies exponentially along the length and for a circular or annular plate whose thickness varies as a power of the radius the large deflexion equations including effects of initial irregularities are also discussed
CRAN	finding zeros of arbitrary functions finding zeros of arbitrary functions a method for finding real and complex roots of polynomial equations due to d muller is applied to finding roots of general equations of the form f z 0 where f z is analytic in the neighborhood of the roots the procedure does not depend on any prior knowledge of the location of the roots nor on any special starting process all that is required is the ability to evaluate f z for any desired value of z multiple roots can also be obtained a general purpose program prepared for the univac scientific 1103 and 1103a is described and numerical results are presented for the following applications finding eigenvalues of differential operators finding eigenvalues of arbitrary matrices finding zeros of the generalized eigenvalue problem finding roots of a number of transcendental equations
CRAN	the buckling of thin cylindrical shells under axial compression the buckling of thin cylindrical shells under axial compression in two previous papers the authors have discussed in detail the inadequacy of the classical theory of thin shells in explaining the buckling phenomenon of cylindrical and spherical shells it was shown that not only the calculated buckling load is 3 to 5 times higher than that found by experiments but the observed wave pattern of the buckled shell is also different from that predicted furthermore it was pointed out that the different explanations for this discrepancy advanced by l h donnell and w flugge are untenable when certain conclusions drawn from these explanations are compared with the experimental facts by a theoretical investigation on spherical shells the authors were led to the belief that in general the buckling phenomenon of curved shells can only be explained by means of a non linear large deflection theory this point of view was substantiated by model experiments on slender columns with non linear elastic support the non linear characteristics of such structures cause the load necessary to keep the shell in equilibrium to drop very rapidly with increase in wave amplitude once the structure started to buckle thus first of all a part of the elastic energy stored in the shell is released once the buckling has started this explains the observed rapidity of the buckling process furthermore as it was shown in one of the previous papers the buckling load itself can be materially reduced by slight imperfections in the test specimen and vibrations during the testing process in this paper the same ideas are applied to the case of a thin uniform cylindrical shell under axial compression first it is shown by an approximate calculation that again the load sustained by the shell drops with increasing deflection then the results of this calculation are used for a more detailed discussion of the buckling process as observed in an actual testing machine
CRAN	the behaviour of a cylindrical shell under axial compression when the buckling load has been exceeded the behaviour of a cylindrical shell under axial compression when the buckling load has been exceeded the value of the compressive stress at which a thin circular cylindrical shell becomes unstable has been worked out theoretically by southwell 1914 subsequent experimental results however have indicated that this value is appreciably too high and that the form of distortion which occurs in practice differs from that assumed in theory in recent years much work has been done on this problem in america lundquist 1933 and donnell 1934 have concluded that the buckling of a cylindrical shell is greatly influenced by initial irregularities von karman and tsien 1941 have indicated that a thin cylindrical shell can be maintained in a buckled state by a compressive load considerably smaller than that previously predicted by theory the present paper is an extension of the work of von karman and tsien it shows that the smallest load which will keep a thin cylindrical shell in a buckled condition is about one third of that given by southwell a result in very fair agreement with experiment and that once the cylinder has buckled and so long as the stresses remain within the elastic range of the material the cylinder has only about one quarter of its original stiffness
CRAN	the behaviour of thin cylindrical shells after buckling under axial compression the behaviour of thin cylindrical shells after buckling under axial compression the fundamental investigations of von karman and tsien on the buckling of cylindrical shells under axial compression are continued the energy expression is simplified and minimized with respect to the axial and circumferential wave length parameters solution of the equations obtained yields curves of the reduced average stress and of the wave dimensions plotted against the reduced average strain they illustrate the behavior of the cylinder during the buckling process the minimum buckling stress is found to be 0 195e tr
CRAN	post buckling behaviour of axially compressed circular cylinder shells post buckling behaviour of axially compressed circular cylinder shells the postbuckling characteristics of an axially compressed thin walled circular cylindrical shell loaded either by dead weights or by a rigid testing machine are determined it is shown that for either loading condition the minimum applied stress in the postbuckling region is 0 182 er and that the region of stable equilibrium corresponding to loading by the rigid testing machine includes and extends beyond that obtained with dead weight loading the work here described is a continuation of work done earlier by von karman and tsien by michielsen and by leggett and jones
CRAN	new developments in the nonlinear theories of the buckling of thin cylindrical shells new developments in the nonlinear theories of the buckling of thin cylindrical shells in the present paper a short survey will be given first of the buckling and postbuckling behavior of isotropic cylindrical shells subjected to different loading conditions as obtained by the nonlinear theory of finite deflections of shells during the last twenty years next a report will be given on new investigations carried out in the structures department of the dvl concerning the elastic stability of isotropic and orthotropic cylindrical shells loaded in axial compression and internal pressure these studies are based on the nonlinear theory of finite deformations the theoretical rsults will be compared with new experimental results obtained with a series of axially loaded pressurized isotropic and orthotropic cylindrical shells
CRAN	lower buckling load in the non linear buckling theory of thin shells lower buckling load in the non linear buckling theory of thin shells for thin shells the relation between the load p and the deflection beyond the classical buckling load is very often non linear for instance when a uniform thin circular cylinder is loaded in the axial direction the load p when plotted against the end shortening has the characteristic shown in fig 1 if the strain energy s and the total potential are calculated their behavior can be represented by the curves shown in figs 2 and 3 it can be demonstrated that the branches oc and ab corresponds to stable equilibrium configurations and the branch bc to unstable equilibrium configurations the point b is then the point of transition from stable to unstable equilibrium configurations
CRAN	an automatic method for finding the greatest or least value function an automatic method for finding the greatest or least value function the greatest or least value of a function of several variables is to be found when the variables are restricted to a given region a method is developed for dealing with this problem and is compared with possible alternatives the method can be used on a digital computer and is incorporated in a program for mercury
CRAN	aeroelastic problems in connection with high speed flight aeroelastic problems in connection with high speed flight a review is given of developments in the field of aeroelasticity during the past ten years the effect of steadily increasing mach number has been two fold on the one hand the aerodynamic derivatives have changed and in some cases brought new problems and on the other hand the design for higher mach numbers has led to thinner aerofoils and more slender fuselages for which the required stiffness is more difficult to provide both these aspects are discussed and various methods of attack on the problems are considered the relative merits of stiffness damping and massbalance for the prevention of control surface flutter are discussed a brief mention is made of the recent problems of damage from jet efflux and of the possible aeroelastic effects of kinetic heating
CRAN	bodt freedom flutter of ground launched rocket models at supersonic and high subsonic speeds bodt freedom flutter of ground launched rocket models at supersonic and high subsonic speeds a theoretical investigation of symmetric body freedom flutter of a rocket model is described the results confirm that structural failures of models were caused by this type of flutter and an extension of the investigation indicates the parameters that are of importance a high ratio of body to wing mass and a well forward position of the overall centre of gravity are conditions under which flutter may occur increase of body pitching radius of gyration and tailplane volume are beneficial it is concluded that this type of flutter may be significant in some aircraft designs and that the canard has no advantage in this respect over the conventional lay out of wing and tailplane
CRAN	subsonic aerodynamic flutter derivatives for wings and control surfaces compressible and incompressible flow subsonic aerodynamic flutter derivatives for wings and control surfaces compressible and incompressible flow this report gives tables of the two dimensional subsonic flutter derivatives where possible the values given are based on the published work of various authors but some have been specially calculated for this report wing derivatives are given for mach numbers 0 0 5 0 6 and 0 7 for the frequency parameter range 0 0 04 0 2 0 2 1 6 and mach numbers 0 and 0 7 for frequency parameter 5 0 control surface derivatives are given for mach numbers 0 and 0 7 for control surface wing chord ratios 0 02 0 02 0 10 0 05 0 50 and frequency parameters are also given for mach numbers 0 0 5 0 6 and 0 7 for frequency parameter 0 0 04 0 2 0 2 1 4 control surface tab derivatives are given for some particular values of the variables and methods of obtaining approximate values of these derivatives for other values of the variables are suggested control surface and tab derivatives are in all cases for no aerodynamic balance
CRAN	the aerodynamic effects of aspect ratio and sweepback on wing flutter the aerodynamic effects of aspect ratio and sweepback on wing flutter the report describes tests to obtain direct measurements of the aerodynamic effects of aspect ratio and sweepback on wing flutter the tests were made on rigid wings with root flexibilities it is shown that measured effects of aspect ratio and sweepback on the flutter of these wings can be represented quite closely in flutter calculations based on two dimensional flow theory by multiplying the two dimensional aerodynamic coefficients by appropriate factors the effect of sweepback is represented by multiplying all aerodynamic coefficients by cos where is the wing leading edge sweepback and the effect of aspect ratio is represented by multiplying the aerodynamic damping coefficients by 1f a and the stiffness coefficients by 1 f a where a is the aspect ratio for the wings tested an average value for f a is f a 1 0 8a
CRAN	transonic flow in two dimensional and axially symmetrical nozzles transonic flow in two dimensional and axially symmetrical nozzles by means of suitable expansions in inverse powers of r the radius of curvature of the nozzle profile at the throat measured in throat half heights the velocity components in the throat region of a convergent divergent nozzle can be calculated the first three terms of the series solution have been obtained both for two dimensional and for axially symmetric nozzles the numerical accuracy of the solution is confirmed by comparison with the known exact solution along the branchline
CRAN	a note on the use of end plates to prevent three dimensional flow at the ends of bluff cylinders a note on the use of end plates to prevent three dimensional flow at the ends of bluff cylinders the results are given of some observations of the effects of end plates on the three dimensional separated flow at the ends of cylindrical models while these are by no means exhaustive it is felt that they are of sufficient interest to merit putting on record
CRAN	slender not so thin wing theory slender not so thin wing theory a method for making an approximate thickness correction to slender thin wing theory is presented the method is tested by applying it to cones with rhombic cross sections and the agreement is found to be good if the cones are not too thick it is then suggested that the thickness correction to slender thin wing theory may be applied unchanged to linear thin wing theory this suggestion is compared with some experiments on delta wings and it is found that there is considerable improvement over thin wing theory near the centre line but that this improvement is not maintained as the wing tips are approached
CRAN	development of a quasi steady approach to flutter and correlation with kernel function results development of a quasi steady approach to flutter and correlation with kernel function results the quasi steady approach to flutter utilizes experimental or theoretical steady state aerodynamic data to arrive at increased understanding of the flutter mechanism and also in many cases acceptably accurate quantitative flutter predictions circulation lag effects are neglected but aerodynamic damping is included in the evaluation of the air forces situations requiring the inclusion of rate aerodynamics for accurate flutter estimation are specified a quasi unsteady approach is also discussed in which the approximate magnitude of the circulation lag function at flutter is included in simple modifications of quasi steady parameters closed form solutions are derived for the flutter characteristics of a typical section with and without rate aerodynamics application is then made to the rational flutter analysis of three dimensional multi degree of freedom lifting surfaces a specific planform is evaluated in the mach number range from zero to two quasi steady quasi unsteady and kernel function results are compared subsonically quasi steady results are utilized supersonically primary applications of the quasi steady approach are in the areas of preliminary design and parameter variation studies modification of more sophisticated flutter theories to force compatibility with available steady state data and flutter evaluation of complex configurations which can be rationally analyzed by steady state aerodynamic theories but for which no complete unsteady aerodynamic theories are presently available
CRAN	heat transfer through laminar boundary layers on semi infinite cylinders of arbitrary cross section heat transfer through laminar boundary layers on semi infinite cylinders of arbitrary cross section this paper shows how to calculate the rate of heat transfer through a laminar boundary layer on a semi infinite cylinder of arbitrary cross section the cylinder is placed in a stream of incompressible fluid the flow at infinity being parallel to the generators and is maintained at a uniform temperature a series solution for small downstream distances and an asymptotic formula for large downstream distances are given to cover the intermediate range an approximate pohlhausen solution is obtained a correction of the error involved in the pohlhausen solution is suggested which it is believed will lead to final errors of at most 2 percent the calculations are applied to elliptic cylinders and illustrate the effect on the local rate of heat transfer of varying the ratio of the major and minor axes of cross section the length of perimeter being held fixed
CRAN	oscillatory derivative measurements on sting mounted wind tunnel models method of test and results for pitch and yaw on a cambered ogee wing at mach numbers up to 2 6 oscillatory derivative measurements on sting mounted wind tunnel models method of test and results for pitch and yaw on a cambered ogee wing at mach numbers up to 2 6 this report describes a method which has been developed for measuring oscillatory derivatives on sting mounted models in the 8 ft by 8 ft supersonic tunnel at r a e bedford direct and cross derivatives with respect to angular displacements and velocities in pitch and yaw have been measured satisfactorily and results are given of tests on a cambered ogee wing at six mach numbers from 0 2 to 2 6 some tests were made on this model in the course of the preliminary development work in the 13 ft by 9 ft low speed wind tunnel and results of these are included
CRAN	further comments on the inversion of large structural matrices further comments on the inversion of large structural matrices in a recent note klein referred to a paper co authored by the writer and to ref 3 regarding the subject of inversion of large order matrices klein stated that he would show that the situation is not as hopeless as the anove mentioned authors intimate the purpose of this note is not to take exception to klein s conclusions but rather to disagree with his implication that the authors of ref 2 were pessimistic with respect to large matrix inversions two general methods of analysis were treated the method of consistent distortion and the method of transfer matrices the first method leads directly to a relatively large matrix of structural coefficients of both internal forces and displacements this matrix must be inverted to solve the problem the second method ultimately produces a relatively small matrix requiring inversion however to arrive at this point one must perform a number of matrix multiplications
CRAN	an investigation of the flow about a plane half wing of cropped delta planform and 6 symmetrical section at stream mach numbers between 0 8 and 1 41 an investigation of the flow about a plane half wing of cropped delta planform and 6 symmetrical section at stream mach numbers between 0 8 and 1 41 a study has been made of the flow development over the wing as the incidence and stream mach number vary and this is illustrated by surface pressure distributions and oil flow patterns the growth and movement of the two main surface shocks the rear and forward shocks is discussed and conditions for flow separation through these shocks are considered for the rear shock which has little sweep these conditions are similar to those for shock induced separation on two dimensional aerofoils the forward shock is comparatively highly swept and separation seems to correspond to two rather different but simultaneously attained conditions one related to the component mach number normal to the shock front and the other to the position of the reattachment line the flow in the region between the leading edge and the forward shock is shown to have certain characteristics analogous to those found upstream of the shock on two dimensional aerofoils to the rear of the forward shock but ahead of the rear shock the flow at low supersonic speeds resembles in some respects that about a simple cone the general flow development is related in the text to the wing lift and pitching moment and the drag the first two are most affected by the aft movement of the rear shock which also stimulates the transonic drag rise the lift dependent drag is shown to be influenced by the appearance of leading edge separation and possibly also by some stage in the development of the forward shock the flow over the cropped delta planform is noteworthy for the absence of the strong outboard shock and this is attributed partly to the cropped tip and partly to the unswept trailing edge a comparison is made with results obtained during preliminary tests in which the wing planform closely resembled that of a true delta
CRAN	the lower bound of attainable sonic boom over pressure and design methods of approaching this limit the lower bound of attainable sonic boom over pressure and design methods of approaching this limit from a study of existing sonic boom theory it has been possible to establish an approximate lower bound of attainable sonic boom overpressure which depends only on the airplane length weight and volume and on the flight conditions this lower bound may be approached over a narrow range of flight conditions through the application of appropriate design considerations in general for intermediate values of lift coefficient the major portion of the lift generating surfaces must be located aft of the maximum cross sectional area whereas for higher values of lift coefficient the maximum area must be well forward and or the lift producing surfaces must extend well toward the airplane nose
CRAN	stability investigation of a blunted cone and a blunted ogive with a flared cylinder afterbody at mach numbers from 0 30 to 2 85 stability investigation of a blunted cone and a blunted ogive with a flared cylinder afterbody at mach numbers from 0 30 to 2 85 a cone with a blunt nose tip and a blunt nose tip and a 20 flared cylinder afterbody have been tested in free flight over a mach number range from 0 30 to 2 85 and a reynolds number range from 1 x 10 to 23 x 10 time histories cross plots of force and moment coefficients and plots of the longitudinal force coefficient rolling velocity aerodynamic center normal force curve slope and dynamic stability are presented with the center of gravity location at about models were both statically and dynamically stable throughout the mach number range for the cone the average aerodynamic center moved slightly forward with decreasing speeds and the normal force curve slope was fairly constant throughout the speed range for the ogive the average aerodynamic center remained practically constant and the normal force curve slope remained practically constant to a mach number of approximately 1 6 where a rising trend was noted maximum drag coefficient for the cone with reference to the base area was approximately 0 6 and for the ogive with reference to the area of the cylindrical portion was approximately 2 1
CRAN	inelastic buckling of initially imperfect cylindrical shells subject to axial compression inelastic buckling of initially imperfect cylindrical shells subject to axial compression an analytical and experimental study is made for inelastic instability of initially imperfect cylindrical shells subject to axial compression donnells equations and the principle of virtual work are adapted to determine the effects of initial imperfections on the buckling modes and the critical buckling stresses the deformation theory and the incremental theory of plastic stress strain relationships are both considered the experimental results of ten tests on specimens made of aluminum alloy 3003 0 are presented comparison of experimental with theoretical results indicates that the application of the deformation theory provides a fairly accurate prediction of buckling strength but fails in this case to yield a correct description of post buckling behavior on the other hand the application of the incremental theory which is mathematically and physically more rigorous leads to an overestimation of buckling strength even though initial imperfections are considered this paradox has existed for years and remains to be resolved
CRAN	buckling of sandwich under normal pressure buckling of sandwich under normal pressure a theoretical study is made of the buckling of a sandwich sphere comprised of a core layer of low modulus material and two thin facing layers of higher modulus material the solution for the buckling resistance of the sphere under normal external pressure is obtained by linearized theory and is reducible to the classical solution for monocoque spherical shells critical buckling pressures are calculated for various radius thickness ratios and sphere materials
CRAN	allowable axial loads and bending moments for inelastic structures under nonuniform temperature distribution allowable axial loads and bending moments for inelastic structures under nonuniform temperature distribution a strain analysis method is derived and demonstrated for the calculation of design allowable load strain curves for the cross section of a structure supporting axial loads and bending moments the temperature effects of thermal stresses and changed material properties and all inelastic effects are included in the calculations so that the final curve is a design curve for the applied stresses as calculated by room temperature elastic procedures the method allows for sequence application and removal of load and temperature as well as cycling of load and or temperature applications are shown for a rectangular bar under temperature cycling with axial loads and or bending moments and for a box beam with one bending moment temperature cycle interaction curves beyween axial load and bending moment with inelastic effects included are given the calculations being done on a digital computer a procedure is given for using the method to construct design curves
CRAN	effects of internal pressure on the buckling of circular cylindrical shells under bending effects of internal pressure on the buckling of circular cylindrical shells under bending the effect of internal pressure on the small deflection buckling of thin walled cylinders under bending is investigated by means of a modified donnell equation the results indicate that the maximum critical stress due to bending increases with internal pressure unlike the case of pressurized cylinders under compression these results represent the moment at which significant deformations appear in the cylinder rather than the maximum moment able to be carried but may be a good approximation to the latter for metal cylinders
CRAN	breathing vibrations of a circular shell with an internal liquid breathing vibrations of a circular shell with an internal liquid resonant breathing frequencies and mode shapes are determined experimentally for a thin walled circular cylindrical shell containing a nonviscous incompressible liquid the resonant frequencies determined for the full shell are in good agreement with those predicted by reissners shallow shell vibration theory with the inclusion of an apparent mass term for the liquid the effect of the internal liquid on the shell mode shapes is significant only for the partially full shell in this case the circumferential node lines tend to shift toward the bottom or filled portion of the shell excitation of low frequency liquid sloshing motion by high frequency forced oscillation of a partially filled shell occurred in many cases this low frequency liquid response is tentatively explained as being excited by a beat frequency in the forced oscillation a similar type of response has been reported by yarymovych in axially excited rigid tanks
CRAN	clamped short oval cylindrical shells under hydrostatic pressure clamped short oval cylindrical shells under hydrostatic pressure the principle of the minimum of the total potential is employed to obtain stresses and displacements for clamped short oval cylindrical shells under hydrostatic pressure classical shell theory in which buckling effects are not considered was used a fourier series is assumed for the deflections in the closed circumferential direction so that the partial differential equations of equilibrium are replaced by a set of ordinary differential equations the energy solution is compared with a simplified approximation which can be considered an equivalent circular cylinder solution graphs of the significant stresses and displacements are presented for oval cylinders having major to minor axis ratios of 1 10 1 30 and 1 50 it is shown that the maximum stresses and displacements increase significantly as the major to minor axis ratio is increased
CRAN	experimental investigation at mach number of 3 0 of effects of thermal stress and buckling on flutter characteristics of flat single bay panels of length width ratio 0 96 experimental investigation at mach number of 3 0 of effects of thermal stress and buckling on flutter characteristics of flat single bay panels of length width ratio 0 96 flat single bay skin stiffener panels with length width ratios of 0 96 were tested at a mach number of 3 0 at dynamic pressures ranging from 1 500 to stagnation temperatures from 300 f to effects of thermal stress and buckling on the flutter of such panels the panel supporting structure allowed partial thermal expansion of the skins in both the longitudinal and lateral directions panel skin material and skin thickness were varied a boundary faired through the experimental flutter points consisted of a flat panel portion a buckled panel portion and a transition point at the intersection of the two boundaries where a panel is most susceptible to flutter the flutter region consisted of two fairly distinct sections a large amplitude flutter region and a small amplitude flutter region the results show that an increase in panel skin temperature flutter the flutter trend for buckled panels is reversed use of a modified temperature parameter which approximately accounts for the effects of differential pressure and variations in panel skin material and skin thickness reduced the scatter in the data which resulted when these effects were neglected the results are compared with an exact theory for clamped panels for the condition of zero midplane stress in addition a two mode transtability solution for clamped panels is compared with the experimentally determined transition point
CRAN	mathematical techniques applying to the thermal fatigue behaviour of high temperature alloys mathematical techniques applying to the thermal fatigue behaviour of high temperature alloys during thermal fatigue testing of a specimen with a thin edge or during rapid temperature changes in the gas flow past turbine blades the thin edges are deformed plastically in compression during heating and subsequently creep in tension as the bulk of the specimen or blade heats up the plastic deformation is determined from temperature distributions which are calculated by biots variational method the creep deformation is determined as a function of time by a differential equation which expresses the balance between increasing elastic stress and reduction of stress due to creep relaxation and which is solved to a riccati equation soluble in terms of bessel functions or iii by transformation to a second order differential equation with a periodic coefficient using the thermal stresses obtained from the solution of the differential equation the theoretical thermal fatigue endurance is determined from cyclic mechanical stress endurance data agreement between theoretical and experimental thermal fatigue endurances is obtained over ranges of temperature strain and strain rate or equivalently over ranges of temperature edge radius and heat transfer coefficient this agreement supports the use of the theoretical methods in wider contexts the accuracy of the temperature distributions is better than the accuracy of other factors entering into the correlation between theoretical and experimental endurances improvement in the interpretation of experimental results requires consideration of the alteration of the stress cycles during the course of thermal fatigue testing this requirement is catered for partially by the various solutions of the differential equation for thermal stress
CRAN	formulae for use with the fatigue load meter in the assessment of wing fatigue life formulae for use with the fatigue load meter in the assessment of wing fatigue life this note gives a method for the derivation of suitable constants which when multiplied by the readings recorded at each appropriate acceleration level on a fatigue load meter and then added together give directly the proportion of fatigue life used up in the wing it is suggested that when the estimated proportion is of order 80 then a more detailed assessment of fatigue life should be made
CRAN	local circumferential buckling of thin circular cylindrical shells local circumferential buckling of thin circular cylindrical shells the problem of circumferential buckling of a thin circular cylindrical shell due to compressive hoop stresses which vary in the axial direction is examined for extremely localised compressive hoop stress distributions resulting from thermal discontinuity effects or from a uniform radial line loading the buckle pattern should also be localised simplified analyses into these two types of problem are considered which show that only a limited number of buckle deflection modes needs to be assumed
CRAN	the flow of a compressible fluid past a sphere the flow of a compressible fluid past a sphere the flow of a compressible fluid past a sphere fixed in a uniform stream is calculated to the third order of approximation by means of the janzen rayleigh method the velocity and the pressure distributions over the surface of the sphere are computed and the terms involving the fourth power of the mach number neglected in rayleighs calculation are shown to be of considerable importance as the local velocity of sound is approached on the sphere the critical mach number that is the value of the mach number at which the maximum velocity of the fluid past the sphere is just equal to the local velocity of sound is calculated for both the second and the third approximations and is found to be respectively and
CRAN	on the flow of a compressible fluid past a sphere on the flow of a compressible fluid past a sphere it was shown by raleigh philos mag 32 1 1916 that the velocity potential for the subsonic flow of a compressible fluid past a sphere can be expressed as a power series in terms of machs number m which is the ratio of the undisturbed velocity u divided by the velocity of sound for the undisturbed flow the equation in question is and boundary conditions are prescribed for raleigh himself computed the first two terms of this series the author finds the third term he gives some graphs showing numerical differences between raleighs and his approximation
CRAN	an experimental study of jet flap compressor blades an experimental study of jet flap compressor blades the results of a preliminary experimental investigation to determine the feasibility of using the jet flap to improve the section characteristics of an axial flow compressor blade are presented and discussed trailing edge internal design of the blade is described and details of the resulting jet flow are given also included are wind tunnel design and test procedures for the two dimensional cascade used in the test test results are presented in the form of the measured turning angle pressure rise and lift coefficient they are examined with particular reference to the prevention of rotating stall
CRAN	q app math 7 1950 381 experiments on porous wall cooling and flow separation control in a supersonic nozzle q app math 7 1950 381 experiments on porous wall cooling and flow separation control in a supersonic nozzle control of flow separation by fluid injection at one diverging boundary of a two dimensional transparent walled de laval nozzle was investigated by spark schlieren photography of dry nitrogen flows expanded from two stagnation temperatures injection conditions at the permeable boundary were varied by the use of three grades of porous stainless steel with nominal pore diameters of 10 20 and 30 microns through which nitrogen was forced by coolant reservoir pressures of 25 50 and 100 psig in addition to the case of no forced injection pressure distribution measurements were made along the nonpermeable diverging boundary it was found that flow separation at expansion ratios approaching the optimum value for maximum thrust coefficient could be induced at the porous wall by a local injection mass velocity of the order of a few per cent of the local main stream mass velocity separation at the solid boundary was not noticeably influenced by injection at the opposite wall and the asymmetrical separation thus effected jet deflections of up to 10 degrees at the lower stagnation pressure levels variation of the wall heat transfer condition by changing the stagnation temperature did not significantly influence separation behavior temperature measurements at the reservoir face of the porous section together with use of published correlations and of the rube sin analysis for estimation of stream side stanton numbers under noninjection and injection conditions respectively permitted heat transfer calculations which indicated that the effectiveness of the transpiration technique in controlling nozzle wall temperatures derives primarily from intimate fluid solid contact in a porous material of high specific surface
CRAN	general characteristics of the flow through nozzles at near critical speeds general characteristics of the flow through nozzles at near critical speeds the characteristics of the position and form of the transition surface through the critical velocity are computed for flow through flat and round nozzles from subsonic to supersonic velocity corresponding considerations were carried out for the flow about profiles in the vicinity of sonic velocity
CRAN	studies on two dimensional flows of compressible fluid studies on two dimensional flows of compressible fluid it is well known that when the flow is everywhere subsonic in a field of flow the nature of the two dimensional isentropic flow of a compressible perfect fluid differs only slightly from that of the corresponding flow of an incompressible perfect fluid thus in such a case we can calculate the field of flow by any of the well known methods of approximation on the other hand if the flow is supersonic throughout the field we can determine the flow pattern by the method of characteristics
CRAN	force measurements on square and dodecagonal sectional cylinders at high reynolds numbers force measurements on square and dodecagonal sectional cylinders at high reynolds numbers results are given of measurements in the compressed air tunnel of the forces on two cylinders one of square cross section and the other dodecagonal the tests were carried out at various reynolds numbers ranging from approximately 0 1 x 10 to 5 5 x 10 based on the distance between parallel faces
CRAN	a technique for rendering approximate solutions to physical problems uniformly valid a technique for rendering approximate solutions to physical problems uniformly valid a method is described for treating some of the characteristically non linear problems of physics in particular those involving a non linear partial differential equation for which an approximate linearization is permissible everywhere except in a limited region such as the neighbourhood of 5 a singular characteristic of the approximate solution or of approximation is valueless the method involves a transformation of an independent variable which is determined progressively with successive approximations to the solution only one step being necessary if a first approximation valid uniformly be obtained the method is most easily understood in its application to simple first order ordinary differential equations which are studied in detail in 2 and 3 as a preparation for the extension to more complicated problems in 4 5 and 6 physically the longest section 6 concerns the spread of a progressive wave at infinity an important and essentially non linear process
CRAN	an integral related to the radiation integrals an integral related to the radiation integrals the author points out the relation of the integral to problems in astrophysics and quantum mechanics and because of its importance supplies a table of values the table gives rl x to seven places of decimals from x 0 to x 6 00 at intervals of 0 01 second order central differences are tabulated to assist in interpolation
CRAN	calculation and compilation of the unsteady lift functions for a rigid wing subjected to sinusoidal gusts and to sinusoidal sinking oscillations calculation and compilation of the unsteady lift functions for a rigid wing subjected to sinusoidal gusts and to sinusoidal sinking oscillations the total lift responses of wings to sinusoidal gusts and to sinusoidal vertical oscillations are calculated from the response to gust penetration and to a sudden change in sinking velocity through use of the well established reciprocal relations for unsteady flow the cases considered are two dimensional wings in incompressible subsonic compressible sonic and supersonic flow elliptical and rectangular wings in incompressible flow wide rectangular and delta wings in supersonic flow and delta wings of vanishingly low aspect ratio in incompressible and compressible flow for most of the cases considered closed form expressions are given and the final results are presented in the form of plots of the square of the modulus of the lift coefficient for wings in a sinusoidally oscillating gust and in the form of the real and imaginary parts of the lift component for wings undergoing sinusoidal sinking oscillations a summary table is presented as a guide to the scope and results of this paper this table contains the figure and equation numbers for the types of flow and plan forms considered
CRAN	the transonic characteristics of 38 cambered rectangular wings of varying aspect ratio and thickness as determined by transonic bump technique the transonic characteristics of 38 cambered rectangular wings of varying aspect ratio and thickness as determined by transonic bump technique an investigation to determine the effects of camber on the aerodynamic characteristics of a series of rectangular wings having various aspect ratios and thickness to chord ratios was conducted in the ames the transonic bump method the mach number range of the investigation was from 0 6 to 1 12 with a corresponding reynolds number range of 1 7 to 2 2 million the lift drag and pitching moment data are presented for wings having aspect ratios of 4 3 2 1 5 and 1 and naca 63a2xx and 63a4xx sections with thickness to chord ratios of
CRAN	use of subsonic kernel function in an influence coefficient method of aeroelastic analysis and some comparisons with experiment use of subsonic kernel function in an influence coefficient method of aeroelastic analysis and some comparisons with experiment this paper illustrates the development and application of an influence coefficient method of analysis for calculating the response of a flexible wing in an airstream to an oscillating disturbing force and for treating such aeroelastic instabilities as flutter and divergence aerodynamic coefficients are derived on the basis of lifting surface theory for subsonic compressible flow by use of the method presented in nasa technical report r 48 application of the analysis is made to a uniform cantilever wing tip tank configuration for which responses to a sinusoidal disturbing force and flutter speeds were measured over a range of subsonic mach numbers and densities calculated responses and flutter speeds based on flexibility influence coefficients measured at nine stations are in good agreement with experiment provided the aerodynamic load is distributed over the wing so that local centers of pressure very nearly coincide with these nine influence stations the use of experimental values of bending and torsional structural damping coefficients in the analysis generally improved the agreement between calculated and experimental responses some calculations were made to study the effects of density on responses near the flutter conditions and linear response trends were obtained over a wide range of densities
CRAN	calculated subsonic span loads and resulting stability derivatives of unswept and 45degree sweptback tail surfaces in sideslip and steady roll calculated subsonic span loads and resulting stability derivatives of unswept and 45degree sweptback tail surfaces in sideslip and steady roll subsonic span loads and the resulting stability derivatives have been calculated for a systematic series of vertical  and horizontal tail combinations in sideslip and in steady roll in order to provide information embracing a wide range of probable tail configurations all calculations were made by application of the discrete horseshoe vortex method to the problem of estimating loads on intersecting surfaces the investigation covered variations in vertical tail aspect ratio the ratio of horizontal tail aspect ratio to vertical tail aspect ratio the effects of horizontal tail dihedral angle for the sideslip case and the effects of vertical position of the horizontal tail for surfaces having their quarter chord lines swept back 0degrees and 45degrees the results of the investigation are presented in charts from which the span loads for the various conditions can be obtained the resulting stability derivatives are presented as vertical  and horizontal tail contributions as well as total tail assembly derivatives the results of this investigation which was made for a wider range of geometric variables than previous studies showed trends which were in general agreement with the results of previous investigations also presented in this paper and used in the computations is an extensive table of values of sidewash due to a rectangular vortex
CRAN	a method for calculating the subsonic steady state loading on an airplane with a wing of arbitrary planform and stiffness a method for calculating the subsonic steady state loading on an airplane with a wing of arbitrary planform and stiffness a method for computing the steady state span load distribution on an elastic airplane wing for specified airplane weights and load factors is given the method is based on a modification of the weissinger l method and applies at subcritical mach numbers it includes the effects of external stores and fuselage on the spanwise loading modifications are outlined for treating tail boom and tailless airplane configurations and for calculating the divergence dynamic pressure of a swept wing with a large external store a method is also outlined for reducing wind tunnel data to obtain effective aerodynamic coefficients which are free of model flexibility effects the effects of mach number can readily be evaluated from the aerodynamic coefficients thus obtained
CRAN	heat transfer through the laminar boundary layer on a circular cylinder in axial incompressible flow heat transfer through the laminar boundary layer on a circular cylinder in axial incompressible flow this paper presents a method of calculating the distribution of rate of heat transfer into a laminar incompressible boundary layer from the exterior surface of a long thin circular cylinder when the surface of the cylinder is maintained at a constant temperature and the flow is parallel to the cylinder axis the temperature difference between the surface and the main stream is taken to be small enough to neglect buoyancy effects a series solution valid for small downstream distances from the nose has been obtained already by seban bond and kelly this is now extended by deriving an asymptotic series solution valid at large downstream distances and bridging the gap between these two series solutions by an approximate solution based on the method used recently by davies and bourne to calculate heat transfer from a flat plate the calculation is used to demonstrate the effect of curvature and of prandtl number on the local rate of heat transfer at various downstream distances by comparing with the corresponding flat plate results
CRAN	the flow of fluid along cylinders the flow of fluid along cylinders the boundary layer equations for uniform flow parallel to the generators of any cylinder without corners are put into the form of a series of linear third order differential equations the first three of these are the same as those obtained by seban and bond 1 for a circular cylinder and solved by kelly 2 the rest have additional terms depending on the radius of curvature of the cylinder and its derivatives the problem is also attacked by a pohlhausen method as far as four terms of the series for large distances from the front rayleighs method as given by hasimoto 3 gives the first two terms of an asymptotic expansion for the drag explicit calculations are made of the drag of an elliptic cylinder of eccentricity 1 2 3 there is evidence that the drag is everywhere less than that of a circular cylinder of the same perimeter
CRAN	the skin friction on infinite cylinders moving parallell to their length the skin friction on infinite cylinders moving parallell to their length the frictional force on a cylinder moving steadily parallel to its length through a viscous liquid which is initially at rest is determined with reasonable accuracy over the whole range of values of the duration of the motion and for a wide variety of shapes of the cylinder cross section when the time t is small the first approximation gives a force per unit area which is the same as that for a flat plate of infinite width the second approximation takes the shape of the cylinder into account and the force on unit length of cylinder is determined in terms of the number of corners and their angles in the cylinder cross linder is the same to this approximation as that on a circular cylinder of the same perimeter for large values of t the determination of the frictional force is reducible to that of a potential problem the solution of which is known for a number of different shapes the approximations for small and large values of t for any one cylinder do not overlap but can be joined without much ambiguity for no value of t do the forces on cylinders of different shape excluding those whose curvature is not everywhere inwards differ by more than about 25 per cent
CRAN	rayleighs problem for a cylinder of arbitrary shape rayleighs problem for a cylinder of arbitrary shape the motion of an incompressible viscous fluid generated by a cylinder of arbitrary cross sectional form which is started to move suddenly from rest with uniform velocity in the direction of its length is considered formulae in powers of are derived for the velocity distribution valid in the vicinity of the cylinder and for the frictional drag on the cylinder correct to the order of a where a is the characteristic length of the cross section v is the kinematic viscosity and t is the time these formulae are given in terms of only the analytic function which maps conformally the region outside the cross section of the cylinder onto the region outside the unit circle and of certain integrals e which are common to any arbitrary cylinder in particular when a is sufficiently small the total frictional drag on the cylinder per unit length is expressed as irrespective of the cross sectional form where b 2 and y 0 5772 eulers constant
CRAN	an approximate boundary layer theory for semi infinite cylinders of arbitrary cross section an approximate boundary layer theory for semi infinite cylinders of arbitrary cross section an estimate is given of the distribution of skin frictional force per unit length and of displacement area on the outside of a semi infinite cylinder of arbitrary cross section moving steadily in a direction parallel to its generators a pohlhausen method is employed with a velocity distribution chosen to yield zero viscous retarding force on the boundary layer approximations the smallness of the fluid acceleration far from the leading edge has been pointed out by batchelor reasonable results atlarge distances from the leading edge however for a large class of cross sections which includes all convex cross sections and locally concave cross sections with re entrant angles greater than 1 2 the method yields the expected square root growth of the boundary layer at the leading edge with a fairly close approximation to the coefficient and it is supposed that the skin frictional force and displacement area are given with reasonable accuracy along the whole length of the cylinder results for the elliptic cylinder and the finite flat plate are given in closed form valid for the whole length of the cylinder and are expected to be in error by at most 20 per cent in addition some estimate is given of the effect of corners on skin frictional force and displacement area
CRAN	a further note on the calculation of heat transfer through the axisymmetrical laminar boundary layer on a circular cylinder a further note on the calculation of heat transfer through the axisymmetrical laminar boundary layer on a circular cylinder by using a karman pohlhausen method the distribution of local rate of heat transfer is ovaluated for the case of air flow in an axisymmetrical laminar boundary layer on a heated circular cylinder the temperature of the cylinder being independent of downstream distance this calculation serves to link the numerical values obtained by seban bond and kelly for small downstream distances to those obtained by bourne and davies for large downstream distances
CRAN	a wind tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds a wind tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds a method is described for measuring the dynamic stability derivatives of a model airplane in a wind tunnel the characteristic features of this system are that single degree of freedom oscillations were used to obtain combinations of rolling yawing and pitching motions that the oscillations were excited and controlled by velocity feedback which permitted operation under conditions unfavorable for more conventional types of oscillatory testing and that data processing was greatly simplified by using analog computer elements in the strain gage circuitry the system described is primarily for measurement of the damping derivatives damping in roll damping in pitch damping in yaw and the cross derivatives rolling moment due to yawing and yawing moment due to rolling the method of testing also permits measurement under oscillatory conditions of the static derivatives rolling moment due to sideslip yawing moment due to sideslip and pitching moment due to angle of attack all these derivatives are of particular importance in estimating the short period oscillatory motions of a rigid airplane a small number of experimental data are included to illustrate the general scope of results obtainable with this system
CRAN	measurements at mach numbers up to 2 8 of the longitudinal characteristics of one plane and three cambered slender ogee wings measurements at mach numbers up to 2 8 of the longitudinal characteristics of one plane and three cambered slender ogee wings measurements have been made of the longitudinal characteristics of one plane and three cambered slender ogee wings p 0 45 at two subsonic and eight supersonic mach numbers up to 2 8 the tests also included measurements of the zero lift pressure drag and support interference of the plane wing the results have been analysed to give data for estimating the performance of supersonic transport aircraft
CRAN	some low speed problems of high speed aircraft some low speed problems of high speed aircraft the first part of the paper deals with the low speed aerodynamics of aircraft shapes suggested by kuchemann at the second international congress in aeronautical sciences at zurich in 1960 as suitable for achieving a required range at supersonic speeds namely wingbody arrangements with sweepback angles of 55degrees or 60degrees and streamwise thickness chord ratio of about 5 per cent suitable for low supersonic speed and slender near triangular wings with sharp leading edges suitable for mach numbers of about 2 or more no attention is given to slewed wings powered lift or variable geometry in dealing briefly with swept wings the need for avoiding separation of flow from the leading edge is demonstrated with the conclusion that it is desirable to use leading edge flaps with blowing or suction at the knee together with blown trailing edge flaps wind tunnel tests are described on a simplified model with these boundary layer control methods applied mention is made of the possibility of adverse ground effect on maximum lift more attention is given to the case of slender wings because their use involves a new type of flow with separation from all edges this flow and its steadiness are therefore discussed from the point of view of the possibility of buffeting the effect of plan form on static longitudinal stability and pitch up is analysed and a short summary of available results on damping in pitch is given large rolling moments due to sideslip are shown to give rise to serious problems of control and the present state of knowledge of static lateral and directional stability and rolling and yawing rotary derivatives is discussed finally the effects of proximity to the ground are summarised the second part of the paper is concerned with work aimed at clarifying some of the requirements for handling qualities of future aircraft it is not so much concerned with forecasts of the dynamic behaviour of these future aircraft as with determining what the pilot wants two aspects of control in the vertical plane are discussed in some detail namely speed control and glide path holding flight tests on an avro 707a aircraft with artificially worsened characteristics are described and it is shown that substantially constant performance in the piloting task can be achieved at the expense of increased pilot effort some tentative conclusions on desirable levels of speed stability and phugoid damping are nevertheless drawn a brief review of the present status of lateral directional handling requirements using mainly american data is also included
CRAN	the flow pattern on a tapered sweptback wing at mach numbers between 0 6 and 1 6 the flow pattern on a tapered sweptback wing at mach numbers between 0 6 and 1 6 the development of the flow pattern on a swept wing with incidence and stream mach number is described the wing of aspect ratio 2 828 taper ratio 0 333 and leading edge sweep 53 5 deg was tested at mach numbers between 0 6 and 1 6 at incidences up to about 12 deg the test reynolds number varied with mach number being typically 2 3 x 10 at m leading edge it is shown that the flow pattern at moderate incidences develops smoothly from a subsonic type involving leading edge separation to a supersonic type where the flow is attached near the leading edge and with shock induced separation further aft the formation and movement of the shock wave system and the vortices near the wing surface are briefly discussed
CRAN	experiments with a tapered swept back wing of warren 12 planform at mach numbers between 0 6 and 1 6 experiments with a tapered swept back wing of warren 12 planform at mach numbers between 0 6 and 1 6 the development of the flow pattern on a wing of aspect ratio 2 828 taper ratio 0 333 leading edge sweepback 53 5 deg and 6 per cent thickness chord ratio in the streamwise direction has been described in part 1 which discussed oil flow patterns obtained on the surface of the wing the complete programme of tests also included pressure plotting at four spanwise stations and force measurements these are discussed in relation to the flow development in this part of the report the wing was tested at mach numbers between 0 6 and 1 6 for incidences up to about 14 deg the tunnel stagnation pressure was held constant at a value near atmospheric pressure during the tests so that the reynolds number varied with mach number at m 1 0 it was 2 3 x 10 based on the mean aerodynamic chord boundary layer transition was fixed by a roughness band at the leading edge a detailed analysis has been made of the pressure distributions on the surface of the wing and the chordwise distributions integrated to determine the spanwise loading the overall lift and pitching moment of the wing were also obtained from these data as well as from direct measurements using a strain gauge balance by means of which the wing drag was also determined these results are considered in some detail to illustrate the effects of mach number and incidence on the flow about the model a preliminary analysis is also made of the conditions for boundary layer separation due to shock waves on the wing surface the principal factor appears to be the component of mach number normal to the shock front
CRAN	the operation of the npl 18in x 14in wind tunnel in the transonic speed range the operation of the npl 18in x 14in wind tunnel in the transonic speed range a brief description of the slotted liners used is given together with the power requirements and some flow surveys some observations are made on wall interference on a half model of a swept wing tested in the wind tunnel
CRAN	an investigation at transonic speeds of the performance of various distributed roughness bands used to cause boundary layer transition near the leading edge of a cropped delta half wing an investigation at transonic speeds of the performance of various distributed roughness bands used to cause boundary layer transition near the leading edge of a cropped delta half wing distributed roughness bands of no 320 and no 500 carborundum were found to be effective in causing boundary layer transition if they extended over the first 5 and 10 respectively of the local chord use of larger grain sizes or increases in the band width for a given grain size resulted in a drag penalty with very large particle sizes about between the particles the drag penalty was constant over the test mach number range 0 80 to 1 15 and decreased slowly with incidence the wing lift and pitching moment were only slightly modified by the presence of any of the roughness bands tested but this result would not of course necessarily apply to wings of other planforms or section shapes the test reynolds number was about 2 7 million in the appendix the structure of the roughness bands is discussed as well as the details of the materials used and the techniques used to apply the band
CRAN	a study of the effect of leading edge modifications on the flow over a 50degree sweptback wing at transonic speeds a study of the effect of leading edge modifications on the flow over a 50degree sweptback wing at transonic speeds summary an investigation has been made in the n p l 18 in x 14 in tunnel of the effects of leading edge modifications on the flow and forces on an untapered wing of 50 deg leading edge sweep at stream mach numbers between 0 60 and 1 20 seven leading edge profiles were tested ranging from a drooped extension of 18 per cent of the chord of the basic sharp nosed section to a round nosed section with a leading edge radius of 1 0 per cent of the basic chord leading edge droop was found to increase the wing drag near zero lift but to reduce appreciably the lift dependent drag component except at the highest test mach numbers droop also increased the lift coefficient at which leading edge separation occurred on the upper surface at moderate subsonic speeds but in addition reduced the mach number for transonic flow attachment the appearance of the forward shock but not the rear shock is considerably delayed when the leading edge is drooped with the undrooped sections an increase in leading edge radius was accompanied by successively earlier appearances of the forward shock and hence the outboard shock with its attendant separation the conditions at which the rear shock first appeared changed only slowly as the section was changed the variations in wing flow pattern as the leading edge is modified are discussed and related to measured changes in the wing lift and drag an attempt is also made to estimate the local mach numbers on some parts of the wing from the oil flow patterns this material is used to assess the flow conditions appropriate to shock induced separation the main section of the report concludes with a tentative discussion of the significance of the present results to the design of swept wings in an appendix results obtained with the wing in a sweptforward configuration are briefly considered
CRAN	interaction between shock waves and boundary layers with a note on the effects of the interaction of the performance of supersonic intakes interaction between shock waves and boundary layers with a note on the effects of the interaction of the performance of supersonic intakes the interaction between shock waves and boundary layers has important effects in many problems of high speed flow this paper has been written as a guide to the literature on the subject and as a critical review of the present state of knowledge concerning both the underlying physical processes and the practical applications it will be clear to the reader that although substantial progress has been made our knowledge is still far from complete and that more work both of a fundamental nature and on specific applications is needed before the problem is understood sufficiently well for design purposes part i of the paper describes experiments on comparatively simple types of flow designed to provide fundamental information and to assist in the development of the theory these experiments show that the interaction depends mainly on the mach and reynolds numbers and on the strength of the shock wave in particular the interaction of a shock wave with a laminar boundary layer is shown to produce much larger effects than if the boundary layer is turbulent for most cases where the effects of the interaction are large enough to have serious practical consequences it is found that the boundary layer separates from the surface and the difference between the interaction with laminar and turbulent layers arises mainly because the laminar layer separates much more readily in an adverse pressure gradient the details of the interaction downstream of the separation point thus depend critically on the behaviour of the separated layer and on the conditions under which it reattaches to the surface many of the features found in the fundamental experiments appear also in practical applications and these are considered in parts ii and iii of the paper although the emphasis hero is on the performance of aerfoils and wings moving at high subsonic speeds the importance of the interaction in other examples such as at supersonic trailing edges and in supersonic intakes is also discussed briefly the differences between the interaction with laminar and turbulent boundary layers are often a source of serious discrepancy between model experiments and full scale conditions for small scale models it is therefore frequently essential to make the boundary layer turbulent by artificial means some of the difficulties involved in doing this and certain of the more promising methods are briefly discussed it is shown that experiments on models with transition fixed can be used to explain a number of aerodynamic effects encountered in transonic flight and connected with the occurrence of shock induced separation of the turbulent boundary layers for both two dimensional aerofoils and straight and sweptback wings turbulent separation occurs for shocks above a certain strength which applies for both model and full scale conditions full scale conditions differences in magnitude would be expected if the pressure recovery along the separated layer between the shock and the trailing edge is affected by reynolds number but little information is at present available on this point most of the repercussions of turbulent separation on the steady motion characteristics of aerofoils and wings can be traced to the associated reduction in the pressure recovery over the roar of the surface this is because the pressure at the trailing edge controls the inter relation between the two surfaces so long as the flow at the trailing edge remains subsonic and in particular the relative movements of the shock waves and the extents of the local regions of supersonic flow certain unsteady flow characteristics such as buffeting and control surface separation some evidence is presented on the influence of section shape on the occurrence and effects of separation but in this as in many other respects information relevant to turbulent boundary layers is scarce some notes on the further work which is required are given in part iv of the paper
CRAN	some effects of wind tunnel interference observed in tests on two dimensional aerofoils at high subsonic and transonic speeds some effects of wind tunnel interference observed in tests on two dimensional aerofoils at high subsonic and transonic speeds in the high speed research on two dimensional aerofoils at the national physical laboratory the need to keep model size above a certain minimum in order to reproduce correctly the boundary layer separation effects experienced at full scale has been considered paramount even at the risk of incurring significant tunnel interference effects this report discusses the interference effects for the slotted working sections now in use the magnitudes of the blockage and lift effect corrections are deduced for the ratio of model chord to tunnel height normally used it is shown that a simple adaptation to reduce the open area of the walls would reduce both corrections to insignificant proportions simultaneously but would give a reduced choking mach number separated flows the observed trends in the variation of the blockage effects for other ratios of model chord to tunnel height differ from those predicted theoretically and so the results cannot be applied more generally until these trends have been checked by further investigations it is suggested that wake interference effects can significantly influence the manner in which separated flows develop with increasing incidence or mach number particularly for walls of small open area examples are also given of effects of distortions in the local supersonic flow which are most noticeable for walls with relatively large open areas
CRAN	wall interference at transonic speeds on a hemisphere cylinder model wall interference at transonic speeds on a hemisphere cylinder model tests have been made in three n p l wind tunnels on a pressure plotting model consisting of a long cylinder with a hemispherical nose the surface pressure distributions were measured for stream mach numbers between 0 7 and 1 1 at zero model incidence and schlieren photographs were taken the blockage ratios were 0 211 0 117 and 0 120 the principal feature of the flow is the effect of working section size on the rate at which the terminal shock wave moves back along the model with increasing stream mach number this is thought to depend mainly on the distance from the model to the slotted walls of the tunnel and not necessarily on the blockage ratio the distance of the solid sidewall is important in influencing the local mach number ahead of the terminal shock by reflecting the expansion wave system originating near the model nose
CRAN	experimental study of the equivalence of transonic flow about slender cone cylinders of circular and elliptic cross section experimental study of the equivalence of transonic flow about slender cone cylinders of circular and elliptic cross section this report describes an experimental investigation of the equivalence relationship and the related theory for lifting forces proposed by transonic slender body theory the models chosen for this study are a flat winglike elliptic cone cylinder and its equivalent body of revolution a circular cone cylinder it is determined that the flows about the two models are closely related in the manner predicted by the theory the relationship persisting over a mach number range of 0 92 to cone cylinder vary linearly only over the small angle of attack range of approximately 1 and that the aerodynamic loading at sonic speed compares favorably with jones slender wing theory the results of the investigation suggest that at transonic speeds and at small angles of attack the calculation of all aerodynamic characteristics of slender three dimensional shapes can be made by use of transonic slender body theory when the pressures on the equivalent body of revolution are known either by experiment or by an adequate nonlinear theory from transonic slender body theory it is deduced that the slenderness required for this application is the same as that required for the successful application of the transonic area rule
CRAN	the behaviour of supersonic flow past a body of revolution far from the axis the behaviour of supersonic flow past a body of revolution far from the axis a theory is developed of the supersonic flow past a body of revolution at large distances from the axis where a linearized approximation is valueless owing to the divergence of the characteristics at infinity it is used to find the asymptotic forms of the equations of the shocks which are formed from the neighbourhoods of the nose and tail in the special case of a slender pointed body the general theory at large distances is used to modify the linearized approximation to give a theory which is uniformly valid at all distances from the axis the results which are of physical importance are summarized in the conclusion 9 and compared with the results of experimental observations
CRAN	the shock pattern of a wing body combination far from the flight path the shock pattern of a wing body combination far from the flight path the position and strength of the front shock wave at large distances from a wing body combination are deduced from the linear theory for the combination using a method developed by whitham the combination consists of a body of revolution and a wing which has thickness and is lifting the effects of interference between the flow over the body and the flow over the wing are included in any direction the flow far from the wing body combination is equivalent to the flow past a body of revolution determined from the configuration of the combination the modified formulae for unsteady flow are given and some results are evaluated for the combination of a body of revolution and a delta wing with subsonic leading edges
CRAN	a flight test investigation of the sonic boom a flight test investigation of the sonic boom the sonic boom as it is now popularly called has become the center of considerable interest during the past few years because of widespread public disturbance and possible damage that can result from it in the hopes of minimizing this disturbance and to extend the general knowledge of the shock waves which produce the booming noise the aeronautical research laboratory wright air development center has initiated an extensive research program to study the sonic boom phenomenon this report presents the results of flight tests undertaken as one phase of this program the tests had as their objective the determination and measurement of the shock wave pressure pattern surrounding an f 100 aircraft in level supersonic flight the flight tests were conducted at the air force flight test center edwards air force base california under the authority of air research and development command test directive no 5524 f1
CRAN	ground measurements of the shock wave noise from airplanes in level flight at mach numbers to 1 4 and at altitudes to 45 000 feet ground measurements of the shock wave noise from airplanes in level flight at mach numbers to 1 4 and at altitudes to 45 000 feet time histories of noise pressures near ground level were measured during flight tests of fighter type airplanes over fairly flat partly wooded terrain in the mach number range between 1 13 and 1 4 and at altitudes from 25 000 to 45 000 feet atmospheric soundings and radar tracking studies were made for correlation with the measured noise data the measured and calculated values of the pressure rise across the shock wave were generally in good agreement there is a tendency for the theory to overestimate the pressure at locations remote from the track and to underestimate the pressures for conditions of high tailwind at altitude the measured values of ground reflection factor averaged about 1 8 for the surfaces tested as compared to a theoretical value of 2 0 two booms were measured in all cases the observers also generally reported two booms although in some cases only one boom was reported the shock wave noise associated with some of the flight tests was judged to be objectionable by ground observers and in one case the cracking of a plate glass store window was correlated in time with the passage of the airplane at an altitude of 25 000 feet
CRAN	ground measurements of airplane shock wave noise at mach numbers to 2 and at altitudes of 60 000 feet ground measurements of airplane shock wave noise at mach numbers to 2 and at altitudes of 60 000 feet the intensity of shock wave noise at the ground resulting from flights at mach numbers to 2 0 and altitudes to 60 000 feet was measured measurements near the ground track for flights of a supersonic fighter and one flight of a supersonic bomber are presented level cruising flight at an altitude of 60 000 feet and a mach number of 2 0 produced sonic booms which were considered to be tolerable and it is reasonable to expect that cruising flight at higher altitudes will produce booms of tolerable intensity for airplanes of the size and weight of the test airplanes the measured variation of sonic boom intensity with altitude was in good agreement with the variation calculated by an equation given in nasa technical note d 48 the effect of mach number on the ground overpressure is small between mach numbers of 1 4 and 2 0 a result in agreement with the theory no amplification of the shock wave overpressures due to refraction effects was apparent near the cutoff mach number a method for estimating the effect of flight path angle on cutoff mach number is shown experimental results indicate agreement with the method since a climb maneuver produced booms of a much decreased intensity as compared with the intensity of those measured in level flight at about the same altitude and mach number comparison of sound pressure levels for the fighter and bomber airplanes indicated little effect of either airplane size or weight at an altitude of 40 000 feet
CRAN	ground measurements of the shock wave noise from supersonic bomber airplanes in the altitude range from 30 000 to 50 000 feet ground measurements of the shock wave noise from supersonic bomber airplanes in the altitude range from 30 000 to 50 000 feet shock wave ground pressure measurements have been made for supersonic bomber airplanes in the mach number range from 1 24 to 1 52 for altitudes from about 30 000 to 50 000 feet and for a gross weight range from about 83 000 to 120 000 pounds the measured overpressures were generally higher than would be predicted by the theory which accounts only for volume effects there is thus a suggestion that lift effects on sonic boom intensity may be significant for this type of airplane for the altitude range of the present tests
CRAN	an investigation of some aspects of the sonic boom by means of wind tunnel measurements of pressures about several bodies at a mach number of 2 01 an investigation of some aspects of the sonic boom by means of wind tunnel measurements of pressures about several bodies at a mach number of 2 01 an investigation of some aspects of the sonic boom has been made with the aid of wind tunnel measurements of the pressure distributions about bodies of various shapes the tests were made in the langley at a mach number of 2 01 and at a reynolds number per foot of 2 5 x 10 measurements of the pressure field were made at orifices in the surface of a boundary layer bypass plate the models which represented both fuselage and wing types of thickness distributions were small enough to allow measurements as far away as 8 body lengths or 64 chords the results are compared with estimates made using existing theory to the first order the boom producing pressure rise across the bow shock is dependent on the longitudinal development of body area and not on local details nonaxisymmetrical shapes may be replaced by equivalent bodies of revolution to obtain satisfactory theoretical estimates of the far field pressures
CRAN	an investigation of the influence of lift on sonic boom intensity by means of wind tunnel measurements of the pressure fields of several wing body combinations at a mach number of 2 01 an investigation of the influence of lift on sonic boom intensity by means of wind tunnel measurements of the pressure fields of several wing body combinations at a mach number of 2 01 an investigation of the effect of lift on sonic boom intensity has been performed by means of wind tunnel measurements of the pressure fields surrounding small wing body combinations the tests were conducted in the langley 4  by 4 foot supersonic pressure tunnel at a mach number of per foot effects of lift were found to be real and significant measured bow shock intensities agreed fairly well with but were consistently less than shock intensities estimated by theoretical methods available flight data were examined for correlation with wind tunnel test results
CRAN	the shock wave noise problem of supersonic aircraft in steady flight the shock wave noise problem of supersonic aircraft in steady flight data are presented which provide an insight into the nature of the shock wave noise problem the significant variables involved and the manner in which airplane operation may be affected flight test data are also given and a comparison with the available theory is made an attempt is also made to correlate the subjective reactions of observers and some associated physical phenomena with the pressure amplitudes during full scale flight it is indicated that for the proposed supersonic transport airplanes of the future booms on the ground will most probably be experienced during the major portion of the flight plan the boom pressures will be most severe during the climb and descent phases of the flight plan during the cruise phase of the flight the boom pressures are of much lesser intensity but are spread laterally for many miles the manner in which the airplane is operated appears to be significant for example the boom pressures during the climb cruise and descent phases can be minimized by operating the airplane at its maximum altitude consistent with its performance capabilities
CRAN	an investigation of lifting effects on the intensity of sonic booms an investigation of lifting effects on the intensity of sonic booms this paper is a brief summary of an investigation made to check the effect of lift on the shock noise of aircraft flying at supersonic speeds the method of hayes has been combined with the theory of whitham to predict the asymptotic shock strength of wings carrying lift and of combinations of bodies and lifting wings a similar but not quite as general method was derived by walkden in ref 6 whithams formula including only the volume term has been used extensively to predict the boom intensity of aeroplane type bodies and the agreement with experiment has so far been quite reasonable the test data obtained to date extends only up to about 40 000 ft altitude and the calculations of this paper show that under those conditions the shock noise of the aircraft tested so far will in most cases be dominated by the volume term it is shown that at higher altitudes lifting effects will dominate for even the small fighter and they will dominate over most of the altitude range for large bomber and supersonic transport aircraft the boom intensity due to lift decreases with altitude as which compares to in the volume case pressure at altitude h it is insensitive to mach number wing loading wing plan shape and lift distribution a simple rule for calculating the shock noise due to combined volume and lifting effects is proposed which is applicable to configurations with wings located towards the rear of the fuselage the rule states that the shock noise of an aircraft carrying lift is equal to the shock noise due to volume neglecting lift or the shock noise due to lift neglecting volume whichever is the greater a chart is presented from which rapid estimates can be made of the shock noise of lifting wing body combinations
CRAN	investigation of two bluff shapes in axial free flight over a mach number range from 0 35 to 2 15 investigation of two bluff shapes in axial free flight over a mach number range from 0 35 to 2 15 a fineness ratio 2 71 right circular cylinder and a fineness  ratio been tested in free flight over a mach number range of 0 35 to 2 15 and a reynolds number range of 1 x 10 to 12 x 10 time histories cross plots of force coefficients rolling velocity and longitudinal force coefficient are presented for both cylinders in addition cross plots of moment coefficients and plots of the normal force curve slope and the aerodynamic center are presented for the fineness ratio 2 71 cylinder the average aerodynamic center of the right circular cylinder moved rearward with decreasing speeds until at the subsonic mach numbers it remained approximately constant and comparisons of the drag data of this test with wind tunnel and other free flight data show good agreement an appreciable decrease in drag was observed when the data of the present test of the rounded nose cylinder were compared with data of a right circular cylinder of a similar configuration
CRAN	the motion of rolling symmetrical missiles referred to a body axis system the motion of rolling symmetrical missiles referred to a body axis system the linearized equations of motion have been derived for a rolling missile having slight aerodynamic asymmetries time histories of rolling missile motions referred to a body axis system have been prepared to show the types of missile motions that can be encountered the motions resulting from a trim change and a pulse rocket disturbance are shown to be determined mainly by the ratio of rolling velocity to pitching frequency finally the derived equations are used in establishing a technique for the reduction of rolling missile oscillation data it is shown that the aerodynamic derivatives can be obtained from flight data if four accelerations are measured the method is applied to the results obtained from a flight test of a missile configuration
CRAN	stability derivatives of cones at supersonic speeds stability derivatives of cones at supersonic speeds the aerodynamic stability derivatives due to pitching velocity and vertical acceleration are calculated by use of potential theory for circular cones traveling at supersonic speeds the analysis is based on two theoretical techniques used successfully previously in application to the case of uniform axial and inclined flow in the first potential solutions for axial flow and crossflow are derived from the first order wave equation but in application to calculations for the forces no approximations are made either to the tangency condition or to the isentropic pressure relation the second method consists in combining the first order crossflow potential with an axial flow potential correct to second order closed form solutions by both methods are found for a cone and numerical results for the stability derivatives are presented as a function of mach number for cones having semivertex angles of 10 and 20 in addition expressions for the forces moments and stability derivatives of arbitrary bodies of revolution are obtained using newtonian impact theory numerical results for cones compare well with those obtained from the combined first  and second order potential theory at the highest mach number for which the latter theory is applicable
CRAN	investigation of several blunt bodies to determine trans  onic aerodynamic characteristics including effects of spinning and of extendible afterbody flaps and some measurements of unsteady base pressures investigation of several blunt bodies to determine trans  onic aerodynamic characteristics including effects of spinning and of extendible afterbody flaps and some measurements of unsteady base pressures several blunt bodies having shapes that may be suitable for atmospheric reentry vehicles were tested to determine the aerodynamic characteristics of such shapes for angles of attack up to 34 the tests were conducted through the transonic mach number range and at reynolds numbers from 1 74 x 10 to 2 78 x 10 based on body diameter a full skirted rather than a short skirted type of shape developed the greatest amount of static stability and the largest lift curve slopes the angle of attack for maximum lift for such bodies appears to be subject to mach number effects spinning a full skirted body about its longitudinal axis generally increased the lift and reduced the pitching moment at angles of attack and reduced the aerodynamic static stability parameter through the transonic mach number range the extension of segmented clamshell shaped flaps from the afterbody of a short skirted model served to increase the lift and static stability only if the flaps extended into the airstream some evidence was found of oscillatory base pressures on two dissimilar shapes at certain high angles of attack and the highest mach number in these tests there is doubt however that these pressures can induce any significant oscillatory motion for a reentry vehicle because of their small amplitude and phasing
CRAN	experimental investigation at a mach number of 3 11 of the lift drag and pitching moment characteristics of a number of blunt low fineness ratio bodies experimental investigation at a mach number of 3 11 of the lift drag and pitching moment characteristics of a number of blunt low fineness ratio bodies a number of blunt bodies having shapes that may be suitable for atmospheric reentry were tested to determine the lift drag and pitching moment characteristics at a mach number of 3 11 and a reynolds number of 6 x 10 based on maximum body diameter of 2 inches the results of the tests showed that all the bodies were statically stable about a point located one third of the body length from the nose the results also showed that high drag bodies which have a large portion of their afterbodies negatively sloped decrease in cross sectional area from nose to base may have a negative lift curve slope this negative slope results from the large negative lift component of the axial force obtained with those bodies and the fact that with negatively sloped afterbodies only small normal forces are developed
CRAN	loading paths and the incremental stress law loading paths and the incremental stress law this paper will be concerned with some properties of the stress strain law for work hardening materials introduced by w prager incremental strain or plastic flow law by which it is meant that the differentials of strain are expressed as functions of the stresses strains and differentials of the stress we shall also have occasion to refer to total strain or plastic deformation laws in which the strains are given directly as functions of the stress
CRAN	a quantitative comparison of flow and deformation theories of plasticity a quantitative comparison of flow and deformation theories of plasticity the stresses and displacements in a partly plastic infinitely long hollow cylinder are obtained according to the flow type of stress strain law of prandtl reuss and to the deformation law of hencky in both cases the mises yield condition is used and the compressibility of the material is taken into account it is shown that under these assumptions the two theories yield substantially the same results for this particular problem but that one theory or the other may be preferable for computing purposes in certain cases the results are compared with those of other investigations in which different combinations of stress strain law yield condition compressibility and end loading were assumed
CRAN	stresses in the plastic range around a normally loaded circular hole in an infinite sheet stresses in the plastic range around a normally loaded circular hole in an infinite sheet the stresses in the plastic range around a normally loaded circular hole in an infinite sheet are found numerically on the basis of both deformation and incremental theories the results of deformation theory are quantitatively assessed in the light of a criterion recently developed by budiansky for the acceptability of deformation theories the criterion is completely satisfied moreover the results obtained by using these two different theories of plasticity do not differ greatly despite the fact that the stress paths are far from being radial
CRAN	theories of plastic buckling theories of plastic buckling the theory for the plastic buckling of columns which appears finally to have achieved a satisfactory form rests upon the well established uniaxial stress strain relation the development of a correspondingly satisfactory theory for the plastic buckling of plates has been hampered by the nonexistence of an established polyaxial stress strain relation in the plastic range present theories for the polyaxial stress strain relation beyond the elastic range can be divided into two types often called flow and deformation theories theories of plastic buckling based on deformation theories are in better agreement with experiment than those based on flow theories on the other hand tests in which a material is compressed into the plastic range and then subjected to shear at constant compressive stress are in better agreement with flow than with deformation theories legitimate doubt therefore has existed as to the validity of any theory for the plastic buckling of plates as a result of studying these apparent contradictions a new theory of plasticity has been developed which is of neither the flow nor the deformation type it is based upon the concept of slip and its formulation was guided more by physical and less by mathematical considerations than previous theories experimental evidence of limited scope but of crucial character is in better agreement with the new theory than with either flow or deformation theories the new theory accounts for the apparent contradictions previously alluded to and justifies the use of deformation theory in the analysis of the plastic buckling of plates
CRAN	inelastic column theory inelastic column theory the action of a column in the plastic range is analyzed on the basis that bending may proceed simultaneously with increasing axial load this leads to a new column formula that includes both the tangent modulus engesser and the reduced modulus the tangent modulus load and that the column load increases with increasing lateral deflection approaching the reduced modulus load as a limit if the tangent modulus is assumed to remain constant
CRAN	effects of imperfections on buckling of thin cylinders and columns under axial compression effects of imperfections on buckling of thin cylinders and columns under axial compression von karman and tsien have shown that under elastic conditions the resistance of perfect thin cylinders subjected to axial compression drops precipitously after buckling it is considered that this indicates that this type of buckling is very sensitive to imperfections or disturbances in this paper the effects of certain imperfections of shape turbances combined are studied by the large deflection shell theory developed in a previous paper 2 it is found that two types of buckling failure may occur one is of a purely elastic type which occurs when the peak of the average stress versus average strain curve is reached while the other type is precipitated by yielding which for thicker cylinders or lower yield material may occur before such a peak is reached curves are derived giving the dependence of each type of failure upon the dimensions and elastic and yield properties of the specimen and also upon an unevenness factor u which determines the magnitude of the initial imperfections and is assumed to depend on the method of fabrication the relations derived are in line with test results and similar studies of the buckling of struts indicate that the magnitude of the initial imperfections which have to be assumed to explain test strengths are reasonable
CRAN	plastic torsional buckling strength of cylinders including the effects of imperfections plastic torsional buckling strength of cylinders including the effects of imperfections the torsional buckling strength of a cylinder in the plastic range has been determined an energy solution and a more exact solution both based on a plastic stress strain relationship given by the simple deformation theory are presented close agreement between the two solutions is found the effects of large deflections and imperfections on buckling strength are analyzed for two groups of experimental results used for comparison the effects of geometrical imperfections in the plastic range are negligible the theoretical results are found to be in good agreement with the experimental results
CRAN	on the concept of stability of inelastic systems on the concept of stability of inelastic systems simple models are employed to bring out the large and important differences between buckling in the plastic range and classical elastic instability static and kinetic criteria are compared and their interrelation discussed nonlinear behavior in particular is often found to be the key to the physically valid solution the nonconservative nature of plastic deformation in itself or in combination with the nonlinearity requires concepts not found in classical approaches conversely the classical linearized condition of neutral equilibrium is really not relevant in inelastic buckling plastic buckling loads are not uniquely defined but cover a range of values and are often more properly thought of as maximum loads for some reasonable initial imperfection in geometry or dynamic disturbance the models indicate that basically the same information is obtained from essentially static systems by assuming initial imperfection in geometric forms as by assuming dynamic disturbances one approach complements the other and both are helpful in obtaining an understanding of the physical phenomena
CRAN	inelastic instability and incremental theories of plasticity inelastic instability and incremental theories of plasticity a most troublesome paradox has existed for a number of years with respect to buckling in the plastic range theoretical considerations and all direct experimental evidence show conclusively that an incremental or flow type of mathematical theory of plasticity is valid however the results of plastic buckling tests are well correlated by a simple total or deformation theory and bear no resemblance to published predictions of incremental theory the suggestion was made that initial imperfections of shape or loading might well explain this most peculiar result however subsequent investigations by several authors seem to have given the impression that excessively large imperfections would be needed and that the answer would be overly sensitive to the magnitude of such imperfections it is the purpose of this paper to demonstrate that extremely small and therefore unavoidable imperfections of shape do account for the paradox in a simple manner the buckling load is shown to be extremely insensitive to the amount of imperfection the example chosen is a simplified version of the long rectangular plate hinged along one edge and free on the other under uniform compressive stress at the ends this is the equivalent of the case of the cruciform column which has been so disturbing in the past because incremental theory applied to a perfect cruciform column did lead to an entirely incorrect result
CRAN	small bending and stretching of sandwich type shells small bending and stretching of sandwich type shells a theory has been developed for small bending and stretching of sandwich type shells this theory is an extension of the known theory of homogeneous thin elastic shells it was found that two effects are important in the present problem which have not been considered previously in the theory of curved shells 1 the effect of transverse shear deformation and 2 the effect of transverse normal stress deformation the first of these two effects has been known to be of importance in the theory of plates and beams the second effect was found to occur in a manner which is typical for shells and has no counterpart in flat plate theory the general results of this report have been applied to the solution of problems concerning flat plates circular rings circular cylindrical shells and spherical shells in each case numerical examples have been given illustrating the magnitude of the effects of transverse shear and normal stress deformation the results of this investigation indicate the necessity of taking account of transverse shear and normal stress in sandwich type shells as soon as there is an order of magnitude difference between the elastic constants of the core layer and of the face layers of the composite shell it was found that the changes due to transverse shear and normal stress deformation in the core may be so large as to be no mere corrections to the results of the theory without transverse core flexibility the actual magnitude of the changes is greatly dependent on the geometry and loading condition of the structure under consideration so that no general rules may be given which indicate for which elastic modulus ratio the changes begin to be significant solutions of problems in the present theory may in general be obtained by mathematical methods which are similar to those employed in the theory of plates and shells without the effect of transverse shear and normal stress deformation included the present work does not include consideration of buckling and finite deflection effects
CRAN	a nonlinear theory of bending and buckling of thin elastic shallow spherical shells a nonlinear theory of bending and buckling of thin elastic shallow spherical shells a shallow spherical dome subjected to lateral pressure is a structure for which the deformation departs appreciably from the linear theory at relatively small values of the deflection amplitude it is also one for which the buckling process is characterized by a rapid decrease in the equilibrium load once the buckling load has been surpassed for structures having this type of buckling characteristics the question arises as to whether the proper buckling criterion to apply is the classical criterion which considers equilibrium with respect to infinitesimal displacements or the finite displacement energy criterion proposed by tsien in this paper the problem of the finite displacement and buckling of a shallow spherical dome is investigated both theoretically and experimentally in the theoretical approach the nonlinear equations are converted into a sequence of linear equations by expanding all of the variables in powers of the center deflection and then equating the coefficients of equal powers the basic parameter for the shallow dome is proportional to the ratio of the central height of the dome h to its thickness t for small values of this ratio the expansions converge rapidly and enough terms are computed to determine the buckling load according to the classical criterion for higher values of h t convergence deteriorates rapidly and it was not possible to determine the buckling load with the number of terms which were computed however even for these higher values of h t the deflection shapes are determined for deflection amplitudes below the amplitude at which buckling occurs these deflection shapes are characterized by their rapid change as h t increases and by the fact that over most of the range of h t studied the maximum deflection does not occur at the center of the dome experimental results seem to indicate that the classical criterion of buckling is applicable to very shallow spherical domes for which the theoretical calculation was made a transition to energy criterion for higher domes is also indicated
CRAN	stresses and small displacements of shallow spherical shells stresses and small displacements of shallow spherical shells the purpose of the present paper is to derive a system of equations which can be used for the analysis of shallow segments of thin elastic spherical shells a segment will be called shallow if the ratio of its height to base diameter is less than say the results obtained on the basis of this assumption will often also be applicable to shells which are not shallow namely then when the loads are such that the stresses are effectively restricted to shallow zones the problem of the spherical elastic shell has been the subject of numerous researches for the rotationally symmetric case the fundamental results were obtained in 1912 1 and have been the starting point of many applications while it is possible to deduce from these results approximate equations equivalent to part of what follows it is believed that the present approach to the problem of the shallow shell may be of some interest even for rotationally symmetric cases a number of investigations have been concerned with the shell loaded in a non rotationally symmetric manner 2 3 4 in its general form this problem is quite difficult and the results so far obtained are not easy to apply restricting attention to the shallow shell in the manner of the present paper brings with it a very considerable simplification of the analysis
CRAN	stability of thin walled tubes under torsion stability of thin walled tubes under torsion in this paper a theoretical solution is developed for the torsion on a round thin walled tube for which the walls become unstable the results of this theory are given by a few simple formulas and curves which cover all cases the differential equations of equilibrium are derived in a simpler form than previously found it being shown that many items can be neglected the solution obtained is length ratio is zero and infinite and is a good approximation for intermediate cases the theory is compared with all available experiments including about 50 tests made by the author the experimental failure torque is always smaller than the theoretical buckling torque averaging about 75 percent of it with a minimum of 60 percent as the form of the deflection checks closely with that predicted by theory and the experiments cover a great range of shapes and materials this discrepancy can reasonably be ascribed largely to initial eccentricities in actual tubes
CRAN	nonlinear deflections of shallow spherical shells nonlinear deflections of shallow spherical shells the equations obtained by chien for the nonlinear deflection of shallow spherical shells under uniform external pressure are solved by means of power series expansions following procedures introduced by friedrichs and stoker in their treatment of buckling of circular plates these equations depend upon two parameters one of these parameters is related to the external pressure while the other depends upon the dimensions of the shell the equations are solved for several ranges of the parameters under boundary conditions corresponding to a fixed edge the solution carried out numerically on the aec univac at new york university yields a complete description of the stresses and deflections as functions of the polar angle over a wide range of values of the loading parameter and the dimensional parameter prediction of the upper buckling load is then made by means of a numerical criterion based on the load vs deflection curve for some cases the postbuckling behavior is investigated the results agree well with existing experimental and theoretical studies and cover a wide range of cases not previously treated
CRAN	buckling of shallow shells under external pressure buckling of shallow shells under external pressure a formula for the initial buckling loads for clamped shallow spherical shells under uniform external pressure is obtained by combining the solutions of two linearized versions of the original nonlinear problem one of these versions is a linear eigenvalue problem while the other is the bending problem for a shallow cap in the linear theory of elasticity the formula which is obtained in a simple manner yields buckling loads that are in better agreement with experiments than previous approximate solutions to the nonlinear problem
CRAN	accelerating convergence of iteration processes accelerating convergence of iteration processes a technique is discussed which when applied to an iterative procedure for the solution of an equation accelerates the rate of convergence if the iteration converges and induces convergence if the iteration diverges an illustrative example is given
CRAN	a simple method of matric structural analysis part iv non linear problems a simple method of matric structural analysis part iv non linear problems the method presented in the previous parts is employed to solve various kinds of nonlinear problems such as problems concerning large deflections or buckling or thermal creep or inelastic stress redistribution involving thermal gradients or design the procedure used in each case is one of direct iteration  i e after one assumes a starting point all subsequent cycles are self generating simple numerical examples are worked out
CRAN	limit design for economical missile structures limit design for economical missile structures a special safety factor alone wont do the trick in the design of lightweight high temperature missile structures if you really want to end up with the most efficient structure you can get an entirely new design approach is needed
CRAN	the problem of strain accumulation under thermal cycling the problem of strain accumulation under thermal cycling parkes and sprague and huang have shown that it is possible for strain growth to occur in a beam structure under temperature load cycling the various aspects of this problem as to criteria for convergence and divergence of the strain accumulation can be simply demonstrated by thermal cycling one element of a two element structure
CRAN	analytical and experimental investigation of stress distributions in long flat plates subjected to lingitudinal loads and transverse temperature gradients analytical and experimental investigation of stress distributions in long flat plates subjected to lingitudinal loads and transverse temperature gradients stress and strain distributions were studied in long flat plates in order to develop practical analytical procedures for the design analysis of aircraft structures at elevated temperatures various load temperature conditions are presented these include methods of analysis for calculation of stress distributions under and plastic range ture experimental verification of the analytical procedures is shown with comparisons between the use of constant room temperature or temperature dependent values of modulus of elasticity and coefficient of thermal expansion the test specimen equipment instrumentation and experimental program are discussed in detail experimental data obtained from the specimen and associated material control coupon tests are presented
CRAN	inelastic behaviour of structures subjected to cyclic thermal and mechanical stressing conditions inelastic behaviour of structures subjected to cyclic thermal and mechanical stressing conditions a general analytical procedure is outlined for structures subjected to varying thermal and mechanical stressing conditions consideration is given to the accumulation of time independent plastic strains and creep strains stress strain temperature time relations for uniaxial and multiaxial stresses are defined based on various material behavior assumptions several of the assumptions are compared with a limited number of time varying temperature and uniaxial stress tests the procedure is illustrated by its application to uniaxial stress problems in which planes originally plane remain plane and to plane stress plate problems a solution based on the influence coefficient approach to the plane stress plate problem is obtained which is applicable to all plate plan forms edge boundary conditions and inplane thermal and mechanical loading conditions from the predicted inelastic behavior of a three bar structure subjected to cyclic thermal and mechanical loading conditions it is shown that eventual failure could result from large permanent deformation accumulations tensile rupture or thermal stress fatigue a sample plate with a centrally located hole was analyzed for two cycles of a time varying temperature and edge stress condition both plastic strain reversals and plastic strain growths were predicted at the hole however a test theory comparison indicated failure by creep rupture
CRAN	bending and compression tests of pressurised ring stiffened cylinders bending and compression tests of pressurised ring stiffened cylinders the results of tests on pressurized ring stiffened cylinders subjected to compression and bending are presented and discussed the results obtained at high values of internal pressure differ from those obtained by previous investigators in that the theoretical small deflection compressive buckling coefficient of 0 6 was nearly achieved in each test small amounts of internal pressure had a greater stabilizing effect in the bending tests than in the compression tests
CRAN	the bending stability of thin   walled unstiffened circular cylinders including the effects of internal pressure the bending stability of thin   walled unstiffened circular cylinders including the effects of internal pressure in a recent paper the authors presented a statistical semiempirical design procedure for the determination of the buckling strength of unpressurized and pressurized cylinders under axial compression this procedure has been extended in the present paper to the bending of unpressurized and pressurized cylindrical shells and allows the calculation of the critical bending stress with a knowledge of the cylinder geometry and the internal pressure only because no published data could be found an extensive series of bending tests of pressurized cylinders has been performed these new data for pressurized cylinders are treated semiempirically together with all of the other known test data for unpressurized cylinders best fit curves are presented using applicable theoretical parameters design curves for determining the critical buckling stress for unpressurized and pressurized cylinders in bending are then developed as 90 per cent probability curves from the test data
CRAN	analysis of partly wrinkled membrane analysis of partly wrinkled membrane a theory is derived to predict the stresses and deformations of stretched membrane structural components for loads under which part of the membrane wrinkles rather than studying in detail the deformations in the wrinkled region the present theory studies average displacements of the wrinkled material specific solutions of problems in flat and curved membranes are presented the results of these solutions show that membrane structures retain much of their stiffness at loads substantially above the load at which wrinkling first occurs
CRAN	on the bending of circular cylindrical shells under pure bending on the bending of circular cylindrical shells under pure bending the stability of circular cylindrical shells under pure bending is investigated by means of batdorfs modified donnells equation and the galerkin method the results of this investigation have shown that contrary to the commonly accepted value the maximum critical bending stress is for all practical purposes equal to the critical compressive stress
CRAN	an improvement on donnells approximation for thin walled circular cylinders an improvement on donnells approximation for thin walled circular cylinders donnells equation for thin walled circular cylinders is replaced by where w is a non dimensional form of the radial displacement and q is the distributed radial loading this equation retains the essential simplicity of the original but unlike donnells equation the accuracy does not decrease as the wavelength of circumferential distortion increases
CRAN	a simplified method of elastic stability analysis for thin cylindrical shells a simplified method of elastic stability analysis for thin cylindrical shells the equation for the equilibrium of cylindrical shells introduced by donnell in naca report no 479 to find the critical stresses of cylinders in torsion is applied to find critical stresses for cylinders with simply supported edges under other loading conditions it is shown that by this method solutions may be obtained very easily and the results in each case may be expressed in terms of two nondimensional parameters one dependent on the critical stress and the other essentially determined by the geometry of the cylinder the influence of boundary conditions related to edge displacements in the shell median surface is discussed the accuracy of the solutions found is established by comparing them with previous theoretical solutions and with test results the solutions to a number of problems concerned with buckling of cylinders with simply supported edges on the basis of a unified viewpoint are presented in a convenient form for practical use
CRAN	flexural vibrations of the walls of thin cylindrical shells having freely supported ends flexural vibrations of the walls of thin cylindrical shells having freely supported ends the paper deals with the general equations for the vibration of thin cylinders and a theoretical and experimental investigation is made of the type of vibration usually associated with bells the cylinders are supported in such a manner that the ends remain circular without directional restraint being imposed it is found that the complexity of the mode of vibration bears little relation to the natural frequency for example cylinders of very small thickness diameter ratio with length about equal to or less than the diameter may have many of their higher frequencies associated with the simpler modes of vibration the frequency equation which is derived by the energy method is based on strain relations given by timoshenko in this approach displacement equations are evolved which are comparable to those of love and flugge though differences are evident due to the strain expressions used by each author results are given for cylinders of various lengths each with the same thickness diameter ratio and also for a very thin cylinder in which the simpler modes of vibration occur in the higher frequency range it is shown that there are three possible natural frequencies for a particular nodal pattern two of these normally occurring beyond the aural range
CRAN	the flexural vibrations of thin cylinders the flexural vibrations of thin cylinders the flexural vibrations of the walls of thin cylinders are considered in this type of vibration many forms of nodal pattern may exist owing to the combination of circumferential and axial nodes theoretical expressions are developed for the natural frequencies of cylinders with freely supported and fixed ends and a comparison is made with the frequencies obtained experimentally in practice the ends of cylinders are subjected to a certain degree of fixing by end plates flanges etc and the natural frequencies thus lie between the corresponding values for freely supported and fixed ends to make possible the estimation of such frequencies a method is devised in which an equivalent wavelength factor is used this factor represents the wavelength of the freely supported cylinder that would have the same frequency as the cylinder under consideration when vibrating in the same mode the results of experimental investigations with various end thicknesses and flange dimensions are recorded and from these the equivalent factors are derived sets of curves calculated for cylinders with freely supported ends and covering a range of cylinder thicknesses are given from these it is possible to obtain close approximation to the frequencies of cylinders under other end conditions by the use of an appropriate factor an example is given of frequency calculations for a large air receiver for which two frequencies were identified by experiment
CRAN	on the vibration of thin cylindrical shells under internal pressure on the vibration of thin cylindrical shells under internal pressure the frequency spectra and vibration modes of thin walled circular cylinders subjected to internal pressure are considered it is shown that for very thin cylinders the internal pressure has a significant effect on the natural vibration characteristics for these cylinders particularly those having smaller length to diameter ratios the mode associated with the lowest frequency is in general not the simplest mode the exact number of circumferential nodes n which occur in the mode associated with the lowest frequency depends on the internal pressure p if this number n is large it decreases rapidly with increasing p when p is small and the fundamental frequency  the lowest frequency at each p  increases rapidly with increasing internal pressure at higher values of internal pressure the frequency spectrum tends to be arranged in the regular manner the frequency increases with the increasing number of circumferential nodes and the lowest frequency rises slowly with the internal pressure experimental results on the frequency spectra vibration modes and structural damping of a series of thin walled cylinders subjected to internal pressure are briefly described these results show agreement with the features predicted by reissners the effect of slight deviation of the cylinder from perfect circular symmetry is discussed
CRAN	experimental study of the vibrations of a circular cylindrical shell experimental study of the vibrations of a circular cylindrical shell an apparatus is described which permits the mode shape of a vibrating circular cylindrical shell to be obtained quite easily these measurements are made without contacting the cylinder and can be converted to actual lineal values a representative number of results obtained with such a system are shown to illustrate the relationship between the nodal pattern and frequency in a cylinder as well as the effect of internal pressure on these frequencies finally comparisons are made between these results and timoshenko theory and an appropriate shell theory
CRAN	the effect of an internal compressible fluid column on the breathing vibrations of a thin pressurised cylindrical shell the effect of an internal compressible fluid column on the breathing vibrations of a thin pressurised cylindrical shell the free oscillations of a thin pressurized cylindrical shell containing a compressible fluid are studied here the use of an approximate set of shell equations shallow shell theory leads to a relatively simple formula for the natural frequencies of the coupled fluid cylinder system the results of some computations are presented
CRAN	a theory of imperfection for the vibrations of elastic bodies of revolution a theory of imperfection for the vibrations of elastic bodies of revolution various observations and preliminary experiments have shown that the effect of imperfections upon the vibrations of bodies of revolution cannot be neglected owing to the possibility of applying the lagrange equation the influence of the imperfections could be traced through the kinetic energy the potential energy and the dissipation function although the fundamental difficulty of the uncertainty of certain variables was not eliminated this procedure permitted at least the making of general qualitative statements as to the behaviour of the system if imperfections are present
CRAN	remarks on donnells equations remarks on donnells equations flugges set of differential equations of equilibrium for circular cylindrical shells is expressed in a form analogous to the donnell equations the results of solutions of the two sets of equations for a simply supported cylinder under a centrally applied uniformly distributed radial line load over a generator segment as well as under sinusoidally applied line loads are in very good agreement for the particular geometry investigated
CRAN	energy expressions and differential equations for stress and displacement analysis of arbitrary cylindrical shells energy expressions and differential equations for stress and displacement analysis of arbitrary cylindrical shells energy expressions and the related equilibrium equations and natural boundary conditions for the determination of the stresses in and displacements of uniform thin walled cylinders of arbitrary cross section loaded in an arbitrary manner by surface and edge forces and moments are presented the derivations are based upon the kirchhoff love assumptions of the classical theory of shells and are performed to within a degree of accuracy employed by flugge in his derivation of the equilibrium equations applicable to circular cylindrical shells hence in terms of stress resultants the exact small deflection equilibrium equations are obtained methods of simplification of the relations derived and of solution of the differential equations presented are indicated
CRAN	stress and displacement analysis of simply supported non  circular cylindrical shell under lateral pressure stress and displacement analysis of simply supported non  circular cylindrical shell under lateral pressure this paper presents an analysis of the deflections of and stresses in a short noncircular cylindrical shell of uniform wall thickness whose median surface cross section is described analytically by a simple expression corresponding to a family of doubly symmetric ovals the cylinder is under a uniform lateral load and is simply supported at its edges the small deflection analysis considered is based upon a series solution of appropriate differential equations of shell theory which leads ultimately to infinite sets of algebraic equations truncated forms of which are considered numerical values of the significant stresses and displacements for points of the oval cylinder which are 5 percent of the axial length and 2 5 percent of the circumferential length apart have been calculated for an oval cross section with a major minor axis ratio of 1 10
CRAN	the accuracy of donnells equations the accuracy of donnells equations solutions of donnells equations of the small deformations of the perfectly elastic thin walled circular cylindrical shell are compared with those obtainable from flugges equations the range of the basic parameters is found within which the two solutions are approximately equal
CRAN	boundary value problems of the thin walled circular cylinder boundary value problems of the thin walled circular cylinder the homogeneous differential equations of donnells theory of thin cylindrical shells are integrated expressions are obtained in closed form for the displacements membrane stresses moments and shear forces
CRAN	simplified formulas for boundary value problems of the thin   walled circular cylinder simplified formulas for boundary value problems of the thin   walled circular cylinder n j hoff has presented formulas which can be used in the solution of boundary value problems of circular cylinders the purpose of this note is to express these results in exact simplified form a more detailed investigation appears elsewhere the notation will be that of hoff unless otherwise stated
CRAN	some experimental studies of panel flutter at mach 1 3 some experimental studies of panel flutter at mach 1 3 experimental studies of panel flutter were conducted at a mach number of 1 3 to verify the existence of this phenomenon and to study the effects of some structural parameters on the flutter characteristics thin rectangular metal plates were used in these studies and were mounted as a section of the tunnel wall most of the data were obtained by using aluminum alloy panels although a few steel magnesium and brass panels were also used different materials with various thicknesses and lengths were used to determine the effect of these parameters on panel flutter the experimental program consisted of three phases panels clamped front and rear and 3 buckled panels clamped on all four edges panel flutter was obtained under controlled laboratory conditions and it was found that at the flow conditions of these tests increasing tensile forces were effective in eliminating flutter as were shortening the panels or increasing the bending stiffness no apparent systematic trends in the flutter modes or frequencies could be observed and it is significant that the panel flutter sometimes involved higher modes and frequencies the presence of a pressure differential between the two surfaces of a panel was observed to have a stabilizing effect initially buckled panels were more susceptible to flutter than panels without buckling buckled panels with all four edges clamped were much less prone to flutter than buckled panels clamped front and rear
CRAN	experimental studies of flutter of buckled rectangular panels at mach numbers from 1 2 to 3 0 including effects of pressure differential and of panel width length ratio experimental studies of flutter of buckled rectangular panels at mach numbers from 1 2 to 3 0 including effects of pressure differential and of panel width length ratio experimental panel flutter data have been obtained at mach numbers from 1 2 to 3 0 for buckled rectangular panels and the effect of a pressure differential has been determined increasing the pressure differential was effective in eliminating flutter on most of the panels tested the effects of the variables in the panel flutter parameter sure e is youngs modulus and t and l are the panel thickness and length respectively were investigated for buckled panels clamped on the front and rear edges and a critical value of this parameter of 0 44 is indicated at zero pressure differential when the panel width length ratio is 0 69 an estimated flutter boundary is presented for buckled panels clamped on four edges with width length ratios of 0 21 to 4 0 this boundary shows that the panel width is more significant than the panel length when the ratio of width to length is less than approximately 0 5 panels clamped on four edges and buckled in two half waves in the direction of flow were found to be particularly susceptible to flutter the results of limited tests on panels with applied damping curvature and lengthwise stiffeners are also presented and discussed
CRAN	experimental investigation at mach numbers 3 0 of the effects of thermal stress and buckling on the flutter of four bay aluminium alloy panels with length width ratios of 10 experimental investigation at mach numbers 3 0 of the effects of thermal stress and buckling on the flutter of four bay aluminium alloy panels with length width ratios of 10 skin stiffener aluminum alloy panels consisting of four bays each bay having a length width ratio of 10 were tested at a mach number of 3 0 at dynamic pressures ranging from 1 500 psf to 5 000 psf and at stagnation temperatures from 300 f to 655 f the panels were restrained by the supporting structure in such a manner that partial thermal expansion of the skins could occur in both the longitudinal and lateral directions a boundary faired through the experimental flutter points consisted of a flat panel portion a buckled panel portion and a transition point at the intersection of the two boundaries in the region where a panel must be flat when flutter occurs an increase in panel skin temperature or midplane compressive stress makes the panel more susceptible to flutter in the region where a panel must be buckled when flutter occurs the flutter trend is reversed this reversal in trend is attributed to the panel postbuckling behavior
CRAN	flutter of aerodynamically heated aluminium alloy and stainless steel panels with length width ratio of 10 at mach 3 0 flutter of aerodynamically heated aluminium alloy and stainless steel panels with length width ratio of 10 at mach 3 0 an investigation of the effects of aerodynamic heating on the flutter of multibay external skin panels has been carried out at a mach number of 3 0 in the langley 9  by 6 foot thermal structures tunnel both aluminum alloy and 17 7 ph stainless steel panels with a length width ratio of 10 for each bay were tested at dynamic pressures between addition a few tests were made on the lower vertical stabilizer of the x 15 airplane which has external skin panels unsupported for a length all panels showed flutter boundaries characterized by an increase in panel thickness required to prevent flutter with increasing thermally induced stress prior to buckling after buckling the panels showed flutter boundaries characterized by a decrease in thickness required to prevent flutter with further increases in thermal stress the largest thickness required to prevent flutter in the presence of aerodynamic heating occurred at the transition between the flat panel boundary and the buckled panel boundary this peak value for aluminum alloy panel was as much as 60 percent greater than the extrapolated value for an unheated unloaded panel values of the modified thickness ratio flutter parameter for the unstressed panels obtained by extrapolation were in fair agreement for the aluminum steel and x 15 stabilizer panels peak values at transition however showed large differences due to apparently minor changes in panel support construction and or changes in panel skin material
CRAN	test of an aerodynamically heated multi   web wing structure mw 1 in a free jet at mach number 2 test of an aerodynamically heated multi   web wing structure mw 1 in a free jet at mach number 2 a multiweb wing structure representing an airplane or missile wing was tested under simulated supersonic flight conditions to determine the transient temperature distribution the aerodynamic loads played an important and unanticipated role however in that the model experienced a dynamic failure near the end of the test the test is discussed and the conclusion reached that the model failed as a result of the combined action of aerodynamic heating and loading the temperature data collected are analyzed and are shown to be in reasonable agreement with calculated values
CRAN	charts adapted from van driests turbulent flat plate theory for determining values of turbulent aerodynamic friction and heat transfer coefficients charts adapted from van driests turbulent flat plate theory for determining values of turbulent aerodynamic friction and heat transfer coefficients a modified method of van driests flat plate theory for turbulent boundary layer has been found to simplify the calculation of local skin friction coefficients which in turn have made it possible to obtain through reynolds analogy theoretical turbulent heat transfer coefficients in the form of stanton number a general formula is given and charts are presented from which the modified method can be solved for mach numbers 1 0 to 12 0 temperature ratios 0 2 to 6 0 and reynolds numbers 0 2 x 10 to 200 x 10
CRAN	the phenomenon of change in buckle pattern in elastic structures the phenomenon of change in buckle pattern in elastic structures a model is analyzed which exhibits the important properties associated with change in buckle pattern of plates the analysis includes a rigorous study of stability in its various modes a discussion of how the present results may be applied to plates and other elastic structures is given
CRAN	loads and deformations of buckled rectangular plates loads and deformations of buckled rectangular plates the nonlinear large deflection equations of von karman for plates are converted into a set of linear equations by expanding the displacements into a power series in terms of an arbitrary parameter the post buckling behavior of simply supported rectangular plates subjected to longitudinal compression and to a uniform temperature rise is investigated in detail by solving the first few of the equations experimental data are presented for the compression problem comparisons are made for total shortening and local strains and deflections which indicate good agreement between experimental and theoretical results
CRAN	status of flutter of flat and curved panels status of flutter of flat and curved panels representative results are presented to show the current status of the panel flutter problem the discussion includes flat panels with and without midplane stresses buckled panels and both unstiffened and stiffened infinitely long circular cylinders
CRAN	a study of the thermal fatigue behaviour of metals the effect of test conditions on nickel base high temperature alloys a study of the thermal fatigue behaviour of metals the effect of test conditions on nickel base high temperature alloys an attempt has been made to identify the significant factors governing the thermal fatigue behaviour of nickel base high temperature alloys mainly by using a laboratory technique with hot and cold fluidized beds as the heating and cooling media a succession of heating shocks is generally more damaging than a succession of cooling shocks between the same temperature limits the duration of the heating shock and the upper temperature of the cycle are dominant factors the thermal fatigue cracks are initiated at the surface and are intercrystalline in origin and propagation surface oxidation which is intergranular in nature for nickel base alloys has a significant effect on thermal fatigue life
CRAN	regularities in creep and hot fatigue data regularities in creep and hot fatigue data published experimental results are assembled to support a previously given theory of uniaxial deformation and the theory is then used to analyse published data on the creep rupture and hot fatigue of engineering materials the theory enables data for different times and temperatures to be classed together thereby providing information over a much greater range of times than could practicably be covered by experiments at a single temperature an underlying numerical pattern common to all the widely different group 8 materials considered then shows through the experimental scatter data for further engineering materials is considered in these terms in part 2
CRAN	low frequency fatigue of nimonic 90 low frequency fatigue   a rheological approach low frequency fatigue of nimonic 90 low frequency fatigue   a rheological approach an alloy of nimonic 90 type has been tested under cyclic loads at temperatures of 800 deg 850 deg and 900 deg cent grahams descriptive theory of deformation has been developed in detail for the tests reported here and shown to provide a satisfactory description of the experimental results the variation of cumulative strain with number of cycles can be described by the sum of powers of cycle number n n n and n there is qualitative agreement between the observed and the calculated stress strain loops the effect of variation of maximum stress per cycle can be described by the sum of power terms with simple exponents within the scatter of observation the total time to fracture is independent of the frequency
CRAN	design and operation of the n g t e thermal shock analogue design and operation of the n g t e thermal shock analogue a description is given of the n g t e thermal shock analogue which is suitable for estimating the temperature in a turbine blade section as a function of position and time when the blade is subjected to a step change in gas temperature the method of operating the analogue and obtaining results has also been described the limitations of the analogue have been stated but they are considered a small penalty in view of the essential simplicity of the design
CRAN	the calculation of transient temperature in turbine blades and tapered discs using biots variational method the calculation of transient temperature in turbine blades and tapered discs using biots variational method transient temperatures in aerofoil sections and tapered discs are calculated taking advantage of simplifications in heat flow analysis achieved in biots variational method cross sections are represented by a line of adjacent squares of various sizes suitable for the local dimensions e g small squares near the leading and trailing edges the potential dissipation and surface dissipation functions of biots method are set up and the lagrange equations lead by automatic procedures to an eigenvalue formulation in matrix form for the temperatures and their first time derivatives solutions are sums of exponentials in time and are evaluated by digital computer requiring about five minutes for each cross section and heat transfer coefficient transient temperatures in a particular aerofoil section for variation of heat transfer coefficient and for external temperature depending exponentially on time agree with results obtained on an analogue computer maximum transient temperature differences are evaluated for tapered discs by a simple electrical analogue with variation of edge radius and heat transfer coefficient peculiarities in the solution for cyclic temperature external to an aerofoil over a range of frequencies indicate limitations in the mathematical formulation a successful solution for cyclic external temperature might enable eigenvalues to be separated out in experimental measurements using electronic equipment and this might be extended to exponential external temperature if a relationship between cyclic and exponential external temperature could be established eigenvalues and eigenvectors as discrete values arise fictitiously from the sub division into squares and the possibility of an integral formulation is mentioned there is a possible but not immediate extension to cooled blades whose cross sections are multiply connected regions transient stresses due to creep and viscoelasticity might be included
CRAN	effect of rheological behaviour on thermal stresses effect of rheological behaviour on thermal stresses since the conventional elastic analysis of thermal stress problems coupled with limiting creep rates and time dependent fracture stresses as inelastic design criteria results in design procedures for thermal stresses in heat exchangers nuclear reactors flight structures at supersonic speeds etc of considerable unreality the effect of various types of rheological behavior viscoelastic plastic work hardening on the level of thermal stresses is analyzed under simplified assumptions such as uniaxial stress and polar or cylindrical symmetry the effect on the thermal stress intensity of the rheological behavior of the material is shown to be very significant particularly with respect to stress relaxation and the development of residual stresses
CRAN	steady state creep through dislocation climb steady state creep through dislocation climb a dislocation climb creep model is considered which does not require the production of immobile dislocations the creep equation that results from the analysis is where a and b are constants is the stress q is the activation energy of creep and kt has its usual meaning this equation is quite similar to one previously proposed
CRAN	fundamentals of boundary layer heat transfer with streamwise temperature variations fundamentals of boundary layer heat transfer with streamwise temperature variations boundary layer heat transfer is analyzed for the case of a sinusoidal distribution of temperature in the direction of flow it is shown that for both laminar and turbulent flow the spatial distribution of heat transfer is generally out of phase with the wall temperature by an angle of 30 to 45 this leads to the conclusion that in some areas the heat flow is opposite to the temperature difference as used in the definition of the heat transfer coefficient and points to the basic shortcomings of this concept the physical explanation for this behavior is found to be the temperature field distortion by the fluid motion the distortion is measured by the peclet number approximate equations representing a conduction analogy were used in this analysis and the validity of these equations for unsteady flow is examined with reference to limitations in frequency and wavelength a solution of these equations is given for the case of a velocity profile which is not a straight line the use of previously developed variational principles for the evaluation of convective heat transfer including cases of three dimensional unsteady flow turbulence and nonparallel streamlines is also discussed
CRAN	lagrangian thermodynamics of heat transfer in systems including fluid motion lagrangian thermodynamics of heat transfer in systems including fluid motion the lagrangian thermodynamic equations of irreversible processes are extended to convective heat transfer this generalization provides equations for the unified analysis of transient heat flow in complex systems comprising solid structures and moving fluids in either laminar or turbulent flow the concept of a surface heat transfer coefficient is eliminated from the formulation the theory is developed along two different lines in one approach a new concept referred to as the trailing function is introduced it represents the surface heat transfer properties and may be evaluated by quite simple but remarkably accurate variational procedures the method of associated fields is also generalized to convective phenomena the second line of approach extends to convective heat transfer the thermodynamic concept of entropy production for both laminar and turbulent flow the theory amounts to an extension of the thermodynamics of irreversible processes to systems for which onsagers relations are not valid
CRAN	the use of models for the determination of critical flutter speeds the use of models for the determination of critical flutter speeds the use of model tests in the prediction of full scale critical flutter speeds is now well established and the technique of such tests is therefore worthy of discussion in order to obtain critical speeds for the model within the speed range of ordinary wind tunnels it is necessary that the model should differ in some respect from a mere small suggested by mckinnon wood the modification of the model consists in a reduction of its effective stiffnesses this method has the defect in most cases probably not serious that the model experiment is conducted at a reynolds number much below that for full scale in the present paper it is pointed out that an alternative method of reducing the critical speed is to increase the mass loading of the model and to make the flutter tests in compressed air it is then quite feasible to reach the full scale reynolds number this method of reducing the critical speeds by a proportionate increase of all effective densities may also be combined with a reduction of the elasticity of the model the relation of model and full scale stresses at the critical flutter speeds is considered where the reduction in critical speed is effected by increase of density only the model and full scale stresses are equal in a model of reduced elasticity the stresses in the wires are the same as for full scale whereas the stresses in the spars are less than for full scale this is in accord with the usual experience that the wires of such a model are the first parts of the structure to fail in a flutter lastly the influence of gravity on flutter is considered this is negligibly small for full scale but not necessarily so for the model gravitational effects can sometimes be corrected by suitable orientation of the model
CRAN	models for aeroelastic investigation models for aeroelastic investigation this addendum provides a short note on two aspects omitted from the original paper viz gravitational effects and structural damping a short list of references to earlier papers dealing with the subject is also added
CRAN	on flutter testing in high speed wind tunnels on flutter testing in high speed wind tunnels the requirements for simulating in a wind tunnel flutter conditions appropriate to high speed flight are discussed and an assessment is made of the desirable features of a wind tunnel suitable for flutter testing at transonic and supersonic speeds it is concluded that such a tunnel should have either the mach number or the stagnation pressure variable during the tunnel run and that it is of considerable advantage and for some purposes essential for high stagnation pressures to be available the stagnation pressure required to allow flight conditions to be simulated with a flutter model is considered to range from at least 2 atmospheres for transonic speeds to about 15 atmospheres for m 4 no attempt to simulate kinetic heating is envisaged although its effect on stiffness should be allowed for in the design of the model to minimise uncertainties due to the variation of the model stiffness with temperature it is desirable that means for controlling the stagnation temperature should be incorporated in the tunnel
CRAN	the influence of aerodynamic heating on the flexural rigidity of a thin wing the influence of aerodynamic heating on the flexural rigidity of a thin wing this report considers the loss of flexural rigidity of a thin wing due to the presence of middle surface stresses resulting from aerodynamic heating the spanwise properties of the wing are assumed constant but the wing section is arbitrary the loss of flexural rigidity is comparable with the corresponding loss of torsional rigidity
CRAN	experimental model techniques and equipment for flutter investigations experimental model techniques and equipment for flutter investigations an outline is given of the uses of flutter models as an aid to the designer in the avoidance of flutter details are given of the different types and methods of construction that are used for flutter models and of the various test facilities that are available for high speed and low speed tests the procedure followed in the u k for flutter clearance of the full scale aircraft is described and the value of the electronic flutter simulator in this field is discussed
CRAN	flutter model testing at transonic speeds flutter model testing at transonic speeds flutter research on reflection plane models of straight swept and delta wings in a 3 x 4 foot transonic test facility techniques of model construction and testing developed
CRAN	the design and testing of supersonic flutter models the design and testing of supersonic flutter models the basic problems of flutter testing in the low supersonic speed range simulate full scale airplanes when mach number is included as a parameter are reviewed and are compared with those where velocity is scaled when the leading edges become transonic these are compared with results given elsewhere and serve as a check on the results of tables i and ii
CRAN	cumulative damage in fatigue cumulative damage in fatigue the phenomenon of cumulative damage under repeated loads was assumed to be related to the net work absorbed by a specimen the number of loading cycles applied expressed as a percentage of the number to failure at a given stress level would be the proportion of useful life expended when the total damage as defined by this concept reached 100 per cent the fatigue specimen should fail experimental verification of this concept for an aluminum alloy using different types of specimens various stress ratios and various combinations of loading cycles is presented these data are also analyzed to provide information on different stress ratios when an s n curve for any one ratio is known results of a sample analysis based on experiments are given it is concluded that a simple and conservative analysis is possible using the concept of cumulative fatigue damage
CRAN	the variation of gust frequency with gust velocity and altitude the variation of gust frequency with gust velocity and altitude information on atmospheric turbulence obtained from counting accelerometer records is examined and relations giving the variation of gust frequency with gust velocity and altitude are obtained the results are summarized in a form convenient for use in estimating the fatigue life of an aircraft
CRAN	correlated fatigue data for aircraft structural joints correlated fatigue data for aircraft structural joints results of fatigue tests carried out at r a e on typical aircraft wing structural joints are correlated to give an indication of general fatigue behaviour the results are plotted in the form of s   log n curves and these indicate that the mode of behaviour cannot be attributed to any single factor such as the type of aluminium alloy the ultimate tensile strength or the mean stress of the fatigue cycle the detailed method of design undoubtedly has a predominant influence on behaviour but this quality is not revealed by a broad classification according to the proportion of load transmitted at holes
CRAN	the estimation of fatigue damage on structural elements the estimation of fatigue damage on structural elements a method is presented for the estimation of fatigue damage to aircraft structural elements the gust spectrum to which the aircraft is subjected is analysed in terms of infinitesimal loading intervals gust data supplied by j taylor for flying below 15 000 ft are used to study fatigue damage in a number of aircraft structural joints and one whole structure
CRAN	buckling of thin cylindrical shells under hoop stresses varying in axial direction buckling of thin cylindrical shells under hoop stresses varying in axial direction the buckling of a thin cylindrical shell simply supported along the perimeter of its end sections is analyzed under hoop compressive stresses varying in the axial direction the thermal stresses arising from a uniform increase in the temperature of the cylinder are determined it is found that such thermal stresses are not likely to cause elastic buckling simple approximate formulas are developed for buckling stress and thermal stress
CRAN	thermal buckling of clamped cylindrical shells thermal buckling of clamped cylindrical shells the problem of thermal buckling of shells arises in connection with air frame bodies subject to aerodynamic heating at supersonic speeds the case of the shell with clamped edges is presented as this case typifies all structures with a tubular shell stiffened at intervals with stiffening rings the shell is assumed to be unrestrained longitudinally and fully restrained laterally at the edges
CRAN	buckling due to thermal stress of cylindrical shells subjected to axial temperature distributions buckling due to thermal stress of cylindrical shells subjected to axial temperature distributions thermal stress distributions in uniform circular cylindrical shells due to axial temperature distributions are investigated the discontinuity effect due to the presence of a cooler stiffening bulkhead is considered and the possibility of thermal buckling of the shell due to the circumferential discontinuity stress is examined the buckling analysis is based on donnells shell equation and particular attention is given to shells having clamped edges an experimental investigation of this buckling problem is discussed and the results obtained are seen to agree reasonably well with theory
CRAN	combinations of temperature and axial compression required for buckling of a ring stiffened cylinder combinations of temperature and axial compression required for buckling of a ring stiffened cylinder a theory is presented to predict the buckling temperature of an axially compressed uniformly heated ring stiffened cylinder the cylinder buckles because of the interaction of the axial stress due to applied compressive loads and the circumferential stress resulting from restraint of thermal expansion by the rings buckling charts covering a wide range of cylinder proportions are presented for both clamped and simply supported cylinders the buckling temperature for a given axial loading is determined from a simple equation involving a coefficient given in the buckling charts and the radius thickness ratio of the cylinder
CRAN	a simplified method of elastic stability analysis for thin cylindrical shells a simplified method of elastic stability analysis for thin cylindrical shells this paper develops a new method for determining the buckling stresses of cylindrical shells under various loading conditions for convenience of exposition it is divided into two parts in part 1 the equation for the equilibrium of cylindrical shells introduced by donnell in naca report no 479 to find the critical stresses of cylinders in torsion is applied to find critical stresses for cylinders with simply supported edges under other loading conditions it is shown that by this method solutions may be obtained very easily and the results in each case may be expressed in terms of two nondimensional parameters one dependent on the critical stress and the other essentially determined by the geometry of the cylinder the influence of boundary conditions related to edge displacements in the shell median surface is discussed the accuracy of the solutions found is established by comparing them with previous theoretical solutions and with test results the solutions to a number of problems concerned with buckling of cylinders with simply supported edges on the basis of a unified viewpoint are presented in a convenient form for practical use in part 2 a modified form of donnells equation for the equilibrium of thin cylindrical shells is derived which is equivalent to donnells equation but has certain advantages in physical interpretation and in ease of solution particularly in the case of shells having clamped edges the solution of this modified equation by means of trigonometric series and its application to a number of problems concerned with the shear buckling stresses of cylindrical shells are discussed the question of implicit boundary conditions also is considered
CRAN	comments on thermal buckling of clamped cylindrical shells comments on thermal buckling of clamped cylindrical shells in the recent paper by zuk an expression was presented for the critical buckling temperature of a clamped cylindrical shell in terms of the material and geometrical properties of the shell restraint at the edges of the shell was assumed to be provided by rigid frames experiencing no temperature rise the circumferential stress induced in the shell when it experienced a temperature rise t may be approximated by the function in other words there is a compressive circumferential stress along the entire length l of the shell it is well known however that the discontinuity stresses introduced at the junction of a shell and a rigid frame or bulk head are extremely localized and the circumferential stresses induced in the shell decrease rapidly away from the joint
CRAN	buckling of a finite length cylindrical shell under a circumferential band of pressure buckling of a finite length cylindrical shell under a circumferential band of pressure this paper is concerned with buckling of a circular cylinder of finite length subjected to a symmetrical band of external pressure both experimental and theoretical results are presented the experimental data were obtained from tests of three thin walled steel cylinders subjected to external pressure by a pneumatic tube encircling the test cylinder at mid length the theory is based on the principle of minimum potential energy and the rayleigh ritz procedure is used to expand the displacement components in trigonometric series theoretical results are given in the form of graphs which show buckling pressure as a function of the following ratios cylinder radius thickness cylinder length radius pressure bandwidth cylinder length theoretical results are in close agreement with existing solutions to special cases in which 1 the pressure is applied over the entire lateral surface and 2 the pressure is concentrated along a circumferential line the theoretical results are also in agreement with the test results
CRAN	research on unsteady flow research on unsteady flow this is a survey of certain recent advances made in the study of aerodynamic unsteady flow and of some of the new problems arising which require further investigation no attempt is made to reproduce classical theory but emphasis rather is laid on validity and general usefulness particular attention being given to unsteady boundary layer effects especially when there is flow separation coverage is broad and author thus provides a useful review for those interested in this field
CRAN	a new design of pitot static tube with a discussion of pitot static tubes and their calibration factors a new design of pitot static tube with a discussion of pitot static tubes and their calibration factors the report describes experiments devised to investigate some of the previously unexplained peculiarities of normal types of pitot static tube in the process use was made of what was as nearly as could be a standard static pressure tube the experiments led to a new alternative design of instrument having a nose of modified ellipsoidal shape and for which the main characteristics have been investigated it has been found to be necessary as well as desirable to include a discussion of the implications of the term calibration factor and although not in this respect comprehensive of the special features and limitations of various pitot static tubes
CRAN	flutter of a two dimensional simply supported buckled panel with elastic restraint against edge displacement flutter of a two dimensional simply supported buckled panel with elastic restraint against edge displacement the critical flutter speed is evaluated for a two dimensional thin buckled panel with one surface exposed to a supersonic airstream and the other to still air at the same static pressure the panel is simply supported along the leading and trailing edges by rigid edge members separated by an elastic member represented by a compression spring the whole system is acted upon by a constant compressive force uniformly distributed along the edge members the aerodynamic forces acting on the deflected panel are found from two dimensional quasi steady theory valid for slow oscillations where the downwash velocity is small compared with the speed of flow and provided that the mach number is sufficiently greater than the elastic behaviour of the panel is given by von karmans large deflection equations modified to cover initially curved plates the solution of the equations is carried out by means of galerkins method which has been shown to give valid results for a panel with a non zero bending rigidity the influence of the midplane compressive force carried by the panel itself the initial buckle amplitude and the elastic restraint against edge displacements is investigated and curves are presented giving the critical dynamic pressure ratio as a function of these variables
CRAN	the airforces on the low aspect ratio rectangular wing oscillating in sonic flow the airforces on the low aspect ratio rectangular wing oscillating in sonic flow approximate expressions for the generalised airforces acting on a rectangular wing of low aspect ratio oscillating harmonically in sonic flow at low frequencies are derived in this paper the modes of oscillation considered are rigid modes and a small selection of flexible modes results are presented as the first few terms of infinite expansions a brief description of the modes of oscillation and of the generalised airforces is given towards the end of the paper so that the results may be used without the main text of the paper having to be read
CRAN	the calculation of loads on a supersonic weapon in the steady circling case the calculation of loads on a supersonic weapon in the steady circling case the economy of a design depends on the accuracy with which it is possible to solve the various structural problems as this has a direct bearing on structure weight this paper describes the calculation of the bending moments on a specific weapon for the high g steady circling case a hybrid method is used to obtain the aerodynamic loads the results presented show the effect of a number of parameters such as   altitude weight acceleration and mach number   on the magnitude of the maximum bending moment
CRAN	some results on buckling and postbuckling of cylindrical shells some results on buckling and postbuckling of cylindrical shells in this summary paper the effects of initial deformations on the buckling and postbuckling characteristics of circular cylindrical shells under hydrostatic pressure is determined in an approximate manner the influence of initial axisymmetric deformations is stressed also the classical buckling of an axially compressed noncircular the results show that the major minor axis ratio of the cross section has a marked effect on the critical load and that use of the maximum radius of curvature in the formula for the classical buckling stress of a circular cylindrical shell leads to good results for moderate eccentricities
CRAN	a survey of buckling theory and experiment for circular conical shells of constant thickness a survey of buckling theory and experiment for circular conical shells of constant thickness a survey of the state of the art for the stability of thin walled conical shells is presented known theoretical results are summarized and compared with experiment the shortcomings of present knowledge and recommended work for the future are discussed
CRAN	aerodynamic effects on boundary layer unsteadiness aerodynamic effects on boundary layer unsteadiness with a view to the study of aerodynamic problems a review is made of boundary layer theory for a flat plate moving with a time dependent velocity unsteady effects are shown to enter according to the magnitude of the ratio of time for diffusion to act throughout the boundary layer to the characteristic time of the imposed unsteadiness it is concluded that a boundary layer may be considered quasi steady even during extreme flight manocuvres generation of acoustic noise purely by boundary layer unsteadiness is generally small thermal and heat transfer effects are cited unsteady boundary layer considerations are important in damping or amplifying certain instabilities such as flutter of panels and stalling flutter of aerofoils in connection with the aerofoil problem laminar separation concepts and the stagnation point boundary layer are described for unsteady flow an analysis of aerofoil lift hysteresis is described using unsteady laminar boundary layer considerations which leads to a prediction of counter clockwise hysteresis at maximum lift
CRAN	some measurements in the vortex flow generated by a sharp leading edge having 65 sweep some measurements in the vortex flow generated by a sharp leading edge having 65 sweep the report is concerned with the vortex flow which arises when separation occurs at a highly swept leading edge measurements were made in the flow over flat plates at 15 incidence each having a sharp leading edge of 65 sweep the pressure and velocity distributions both along the axis of the vortex and for one cross section of the flow are presented together with a preliminary discussion of their significance
CRAN	long slender delta wings with leading edge separation long slender delta wings with leading edge separation the slender body approximation of linearized compressible flow is applied to the problem of a delta wing in which flow separation occurs at the leading edges the vortex sheets found in the real flow are approximated by concentrated vortices with feeding lattices and a plausible adaptation of kelvins theorem is applied to simulate the force free nature of the vortex sheet the computations show that leading edge separation produces an increase in lift over that given by the jones slender wing theory and that the lift does not vary linearly with angle of attack computed pressure distributions and span loadings are presented and the theoretical lift results are compared with the results of simple force tests made at a mach number of 1 9
CRAN	some current and proposed investigations into the flow for slender delta and other wings in unsteady motion some current and proposed investigations into the flow for slender delta and other wings in unsteady motion the practical need for research into the aerodynamics of slender delta wings in unsteady motion has been emphasized in a recent paper by zbrozek two important aspects are   formation and presence of leading edge vortices with oscillatory or transient modes of longitudinal or chordwise bending the first of the aspects above has already been briefly discussed in ref 2 one feature of the flow with leading edge vortices which seems to be of particular significance to the dynamic behaviour of a wing is the shedding of vorticity at the leading edge as well as at the trailing edge any time dependent motion or distortion of the wing leads to a change in the rate at which vorticity is shed with more conventional types of flow the free vorticity being shed only from the trailing edge has diminishing influence on the wing but when the free vorticity is shed from the leading edge in passing downstream it remains close to the upper surface of the wing it might be expected then that although the magnitudes of the unsteady forces may not be greatly affected for a slender delta the time delays associated with the forces may be significantly different for the attached and separated regimes of leading edge flow
CRAN	two dimensional transonic unsteady flow with shock waves two dimensional transonic unsteady flow with shock waves a study is made of the unsteady flow around an airfoil at transonic mach numbers the situation being such that local supersonic regions terminated by shock waves are present in the vicinity of the airfoil for the unsteady part of the flow small perturbations technique is employed and the interaction with the shock wave is taken into account the case of an oscillating aileron is considered first and a solution is derived for the pressure distribution on the aileron it is found that the solution has a simple form when the shock wave is well ahead of the hinge axis of the aileron as the shock approaches the hinge axis a correction must be added to the solution an interpretation of these results is given the results are compared with results of a theory which neglects the presence of the shock and it is found that both agree for m 1 for m 1 however neglecting the presence of the shock waves introduces errors of the order of magnitude 1   m where m is the local mach number behind the shock the theory is finally extended to include the case in which the whole airfoil oscillates but only the solution for the subsonic region behind the shock is treated the role of the unsteady shock boundary layer interaction is discussed and it is shown that this mechanism can be included in the results of the present theory
CRAN	calibration of the standard pitot static head used in the rae low speed wind tunnels calibration of the standard pitot static head used in the rae low speed wind tunnels recent results of tests in the r a e wind tunnels concerned with the measurement of pressure distributions have shown slight discrepancies between the readings of various static pressure tubes and calculated pressure distributions as a consequence some doubt was felt concerning the calibrations of tunnel static pressure and upon the validity of the reading given by the standard pitot static head it was therefore decided to check the standard pitot static head used in the r a e wind tunnels against an instrument similar to the measurements of static pressure were also made using a long tube where the interference from head and support is calculated to be small this note gives the results of tests made in the 5 ft open jet wind tunnel and the no 1 11 ft wind tunnel in order to determine the necessary correction to the reading of static pressure given by the r a e pitot static head the tests were made during september and october 1951
CRAN	comparative tests of pitot static tubes comparative tests of pitot static tubes comparative tests were made on seven conventional pitot static tubes to determine their static dynamic and resultant errors the effect of varying the dynamic opening static openings wall thickness and inner tube diameter was investigated pressure distribution measurements showing stem and tip effects were also made a tentative design for a standard pitot static tube for use in measuring air velocity is submitted this report covers an investigation conducted under the auspices of the national research council
CRAN	review of the pitot tube review of the pitot tube this paper is an attempt to bring together the important information regarding pitot tubes and their use to summarize the available data on the application of various types of impact and velocity probes for the guidance of engineers and research workers and to aid them in the design of flow instruments for specific applications
CRAN	cavitation and pressure distribution head forms at zero angle of yaw cavitation and pressure distribution head forms at zero angle of yaw early in the fall of 1943 the iowa institute of hydraulic research undertook the design and fabrication of a variable pressure water tunnel as the tunnel neared completion however its immediate use for the study of the pressure distribution around various body forms was requested the original request for this investigation was a natural out growth of the need for systematic data on the distribution of pressure in flow around various bodies particularly under conditions leading to cavitation information which is desirable for the design of a wide variety of navy equipment ultimately the study is to include data for two  and three dimensional head and tail forms at various angles of yaw the first phase of the study namely the investigation of three dimensional head forms at zero angle of yaw is described herein three general geometric series have been studied dash rounded ellipsoidal and conical dash together with other related forms the data obtained have been systematized to yield information for a wide variety of geometrical forms either directly or by interpolation whenever possible analytical methods have been used to corroborate the experimental data and to provide a reliable means of generalizing the results
CRAN	random vibration random vibration random vibration is vibration which results from an excitation which is not well represented by any simple function sinusoid step etc or any simple combination of such functions but which is satisfactorily modeled by a stochastic process it is perhaps not too much of an exaggeration to say that all vibration is random vibration every vibration record contains hash at some level nevertheless until recently engineering vibration theory has been able to get along without including the consideration of random excitations now in several fields simultaneously there has occurred a burst of activity in the application of random processes the response of aircraft to buffeting from atmospheric turbulence and the response of ships to confused seas have been put on reasonably firm footing possibly the most dramatic problems have been posed by the development of large jet and rocket engines which produce spectacular amounts of random vibrational energy the high level of random vibration in a jet plane or a missile provides a severe environment with respect to fatigue failure of structural members and with respect to malfunctions of sensitive equipment
CRAN	the effect of jet noise on aircraft structures the effect of jet noise on aircraft structures the present state of knowledge on the problem of fatigue failure due to vibrations excited by jet noise is reviewed it is concluded that it should currently be possible to make reasonable estimates of the stress levels set up in a structure by jet noise but in general the resultant fatigue life of the components cannot be estimated with any confidence
CRAN	natural frequencies of continuous beams of uniform span length natural frequencies of continuous beams of uniform span length a simple graphical network is used to determine the natural frequencies of flexural vibration of continuous beams having any number of spans of uniform length the network is based upon a relatively few calculated values
CRAN	experimental study of the random vibrations of an aircraft structure excited by jet noise experimental study of the random vibrations of an aircraft structure excited by jet noise recordings have been made of the strains induced in a full scale rear fuselage test structure of the caravelle air liner when one jet engine is running at maximum take off thrust the analysis has been concentrated on the strains in the centres of panels correlation measurements indicate that the larger panel strains occur above resonance peak in each panel has been identified with the fundamental stringer twisting mode but the mode shapes for the two smaller peaks have not been completely determined an attempt has been made to calculate the panel resonant frequencies theoretically
CRAN	the axisymmetric free convection temperature field along a vertical thin cylinder the axisymmetric free convection temperature field along a vertical thin cylinder with a view to studying the effect of strong transverse curvature on boundary layer problems the axisymmetric free  convection problem along a vertical thin cylinder is investigated theoretically as well as experimentally a theory is developed as an extension of the pohlhausen solution of a thick axisymmetric laminar boundary layer by mark and by glauert and lighthill experiments consist of a thermocouple survey of the temperature field over an electrically heated brass cylinder of diameter and 10 ft height and an interferometric study of the density field over a bare tungsten wire of 0 02 in diameter and 5 ft height the thermal layer thicknesses are about five and fifty times the radii of the cylinders respectively experimental results of the local heat transfer coefficient are in excellent agreement with the theory this in turn justifies the theories of laminar boundary layer along a thin cylinder at least indirectly
CRAN	vibrations of beams on many supports vibrations of beams on many supports the natural frequencies of a continuous beam resting on an arbitrary number of uniformly spaced supports are determined from a difference equation formulation these frequencies fall in periodically spaced groups that are separated by spectral gaps of widths equal to approximately half the interval between the natural frequencies of a single beam on a square root frequency scale these groups tend to uniform spectra as the number of supports tends to infinity but the gaps remain giving a band pass character to the entire spectrum wave propagation along an infinite periodically supported beam is discussed and the phase and group velocities evaluated as functions of frequency
CRAN	transtability flutter of supersonic aircraft panels transtability flutter of supersonic aircraft panels for certain aero elastic configurations it is possible to ascertain critical flutter conditions from static considerations alone the idea is simply one of negation when the air speed exceeds a certain value statically stable equilibrium   and sometimes equilibrium itself take place there are times when the dynamics of a situation are complex enough to defy a tractable analysis the value of being able to indicate a flutter criterion from the simpler statics is clear we will suppose flutter begins when some critical value of the air speed or some parameter simply related the to is exceeded here we will show that there is a critical value which when exceeded precludes static equilibrium underlying our work is the premise that these two critical values are the same this assumption begs discussion we will call the lowest value of our air speed parameter to preclude statically stable equilibrium of the system the transtability value in some cases excess of this value will ban all possibility of static equilibrium   stable or not we will then call it a strong transtability value
CRAN	a buckled plate in a supersonic stream a buckled plate in a supersonic stream the forcible buckling of an external skin plate from a guided missile with a pinned end is considered in a supersonic air flow conidtions of dynamic stability orthogonality and expansion of the buckling mode the degree of freedom and cases of small deflection are considered without a 50 half angle conical afterbody in a pressurized ballistic of range at nominal mach numbers of 3 5 and of 90000 and 220000 respectively it
CRAN	the flow around oscillating low aspect ratio wings at transonic speeds the flow around oscillating low aspect ratio wings at transonic speeds when certain conditions are fulfilled for thickness ratio aspect ratio and reduced frequency for a three dimensional wing it can be shown that the partial differential equation for the non steady perturbation potential can be reduced to a comparatively simple linear equation the solution is then obtained by applying a fourier transformation in the free stream direction and then using an iterative process developed by adams and sears for steady flow the method gives solutions valid for low combinations of aspect ratio and reduced frequency the method is applied to a delta wing oscillating in some selected rigid and elastic modes from the results it can be seen that the special non steady forces in the potential equation which are neglected in slender body theory are very important stability derivatives can also be obtained by the method and it is seen that the damping in pitch may be negative at m 1 for delta wings of too high aspect ratio
CRAN	a method of calculating the short period longitudinal stability derivatives of a wing in linearised unsteady compressible flow a method of calculating the short period longitudinal stability derivatives of a wing in linearised unsteady compressible flow a method is developed for the calculation of the pressure distribution and the aerodynamic forces and moments on a wing performing harmonic pitching and heaving oscillations the calculation is based on the assumption of inviscid potential flow without shock waves and is restricted to small incidence so that the linearized theory is valid in contrast to other work in the field the theory applies to all mach numbers it is restricted to small values of the reduced frequency and should be valid for the usual range of short periods occurring at present in flight the formal solution yields two integral equations for the parts of the load which are in phase and go out of phase with the oscillation these are of the same form as the corresponding equation in steady flow the way is thus opened for solutions over the whole mach number range at small frequencies if the corresponding steady solutions can be found the calculation is in fact easiest for m 1 and has been done here for delta wings to supplement a previous supersonic calculation made on different frequency assumptions which broke down near m 1 it appears from the two sets of results that the short period oscillation will be unstable near m 1 if the apex angle of the delta wing is greater than about 60 this confirms a now generally recognised trend such results near m 1 must of course be invalidated to an unknown extent by thickness viscosity and shock waves at their maximum effect nevertheless it is unlikely that these factors will remove the critical nature of the transonic damping as calculated by this method with all its obvious limitations this method when extended to other planforms should provide a useful tool in studying the effect of geometrical parameters on the stability of an aircraft at transonic speeds
CRAN	on the low aspect ratio oscillating rectangular wing in supersonic flow on the low aspect ratio oscillating rectangular wing in supersonic flow the laplace transform of the lift distribution on an oscillating rectangular wing in a supersonic flow is obtained by separating the linearised equation for the velocity potential in elliptic cylindrical co ordinates the results for the case of no spanwise distortion are expanded in ascending powers of the aspect ratio in order to compare with the slender body theory and the longitudinal stability derivatives are calculated it is found that at either supersonic or transonic speeds single degree  of freedom instability in pitch is impossible insofar as the fourth power of the aspect ratio is neglected
CRAN	theoretical studies of unsteady transonic flow part iii the oscillating low aspect ratio rectangular wing theoretical studies of unsteady transonic flow part iii the oscillating low aspect ratio rectangular wing by expanding the velocity potential in an asymptotic series the aerodynamic forces on an oscillating low aspect ratio rectangular wing are calculated the approximate theory is valid for small values of ko o semi span to chord ratio k reduced frequency and complements an earlier low aspect ratio wing theory by the author valid only for pointed wings like delta wings the present report gives formulas for the calculation of generalized forces for any smooth flexible or rigid mode of oscillation with spanwise symmetry comparisons with the slender wing theory show that except for wings of very low aspect ratio unsteady flow effects are appreciable even at fairly low reduced frequencies near the upper limit in ko for the applicability of the present theory good agreement is obtained with a recent theory for high aspect ratios
CRAN	supersonic flow over an inclined wing of zero aspect ratio supersonic flow over an inclined wing of zero aspect ratio an asymptotic expression is found for the lift distribution on a long narrow laminar wing at incidence in a supersonic stream the approximations of the linearized potential theory are used
CRAN	slender body theory review and extension slender body theory review and extension the approximate theory of flow about slender bodies and wings originated by munk and jones is reviewed it is presented here in a form that emphasizes the relation to the source sink methods of von karman and others the extension to noncircular bodies is made for subsonic flow paralleling wards extension for supersonic flow the calculation of pressures and forces and the extension of the theory to unsteady flows are reviewed and some discrepancies in the published literature are explained finally interpreting the jones slender wing result as the first term of an expansion in powers of a breadth parameter e g aspect ratio it is shown how a more accurate theory can be developed by carrying additional terms for both subsonic and supersonic speeds this theory of not so slender wings is applied to some practical wing problems including direct problems of flow past given wings and problems of wing design for minimum drag the accuracy of the new results is assessed by comparison with linearized supersonic airfoil theory for the special case of a flat delta wing
CRAN	supersonic flow past slender bodies of revolution slope of whose median section is discontinuous supersonic flow past slender bodies of revolution slope of whose median section is discontinuous the theory of supersonic flow around slender bodies of revolution yawed or unyawed with pointed or open bows based on the linearized equation is extended to the case when the meridian section of the outer surface has discontinuities in slope expressions for the pressure distribution on the surface are obtained it is found that the drag coefficient is no longer independent of mach number and tends to zero more slowly than the square of the thickness of the body the large pressure change behind a discontinuity is made up remarkably rapidly the first approximation to the lift coefficient is unchanged
CRAN	methods for estimating lift interference of wing body combinations at supersonic speeds methods for estimating lift interference of wing body combinations at supersonic speeds the modified slender body method used by nielsen katzen and tang in rm a50f06 1950 to predict the lift and moment interference of triangular wing body combinations has been adapted to combinations with other than triangular wings that part of the method for predicting the effect of the body on the wing has been retained but a new method for predicting the effect of the wing on the body has been presented these methods have been applied to the prediction of the lift curve slopes of nearly 100 triangular rectangular and trapezoidal wing body configurations the estimated and experimental values for the lift curve slopes agree for most of the cases within 10 percent some of the higher order effects that must be taken into account in a theory that is to give greater accuracy than the present one are discussed a numerical example illustrating the method is included
CRAN	a method for calculating the lift and centre of pressure of wing body tail combinations at subsonic transonic speeds a method for calculating the lift and centre of pressure of wing body tail combinations at subsonic transonic speeds a method is presented for calculating the lift and pitching moment characteristics of circular cylindrical bodies in combination with triangular rectangular or trapezoidal wings or tails through the subsonic transonic and supersonic speed ranges the method covers unbanked wings sweptback leading edges or sweptforward trailing edges low angles of attack and the effects of wing and tail incidence the wing body interference is handled by the method presented in naca rms a51j04 and a52b06 and the wing tail interference is treated by assuming one completely rolled up vortex per wing panel and evaluating the tail load by strip theory a computing table and set of design charts are presented which reduce the calculations to routine operations comparison is made between the estimated and experimental characteristics for a large number of wing body and wing body tail combinations generally speaking the lifts were estimated to within 10 percent and the centers of pressure were estimated to within effect of wing deflection on wing tail interference at supersonic speeds was not correctly predicted for triangular wings with supersonic leading edges
CRAN	factors affecting loads at hypersonic speeds factors affecting loads at hypersonic speeds this paper gives a brief summary of current loads information at hypersonic speeds several methods which the designer can employ in estimating the loads on various aircraft components are discussed the paper deals with the characteristics of both slender and blunt configurations and touches upon the effects of boundary layer and aerodynamic interference
CRAN	post buckling behaviour of circular cylinderical shells under hydrostatic pressure post buckling behaviour of circular cylinderical shells under hydrostatic pressure the postbuckling behavior of initially perfect thin walled circular cylindrical shells under hydrostatic pressure is investigated with the aid of the principle of stationary potential energy together with appropriate approximate deflection functions calculations show that postbuckling equilibrium configurations exist for loads greater than as well as loads slightly less than the critical load calculated from small deflection theory loads less than the critical load are obtained only for a finite range of a parameter indicative of shell geometry for loads corresponding to radial displacements of the order of the shell thickness it is found that the number of circumferential waves remain essentially constant with increasing deflection and equal to the number of waves developed at buckling
CRAN	investigation of normal force distributions and wake vortex characteristics of bodies of revolution at supersonic speeds investigation of normal force distributions and wake vortex characteristics of bodies of revolution at supersonic speeds the supersonic aerodynamic characteristics of inclined bodies of revolution at high angles of attack have been investigated in order to provide a more basic understanding of the body vortex wake flow and its relation to the problem of body wing interference the results of wind tunnel tests whereby the normal force pitching moment normal force distributions and the local flow properties in the vicinity of the body were determined are discussed and analyzed comparisons of experimental normal force coefficient and center of pressure data with values calculated in accordance with theories which include methods for estimating the effects of viscosity show that the accuracy of these estimates is strongly dependent on the body fineness ratio and the angle of attack further comparisons of the distributions of theoretical and experimentally derived cross flow drag coefficients clearly show that in general the disagreement between experiment and existing theories is due to the inadequate prediction of the magnitude and distribution of the forces resulting from flow separation the circulation strengths of the concentrated vortices and the circulation strengths of the vortex feeding sheets in the body vortex wake are determined by closed contour velocity perimeter integrations for paths enclosing the vortex or the feeding sheet the values of vortex strength calculated in this manner are in close agreement with the values predicted by vortex strength formulas written for a simple theoretical model for which it is assumed that the cross flow in any plane along the cylindrical portion of the body is represented by the steady incompressible potential flow about a cylinder two symmetrical vortices of equal strength and the attendant image vortices however in computing these strengths it is necessary to use the vortex locations and the viscous normal force distributions determined from experiment the experimentally determined values of vortex strength are in turn used to calculate  by means of the aforementioned incompressible cross flow potential  the local flow inclination angles which are in good agreement with the measured values except in the vortex core in the vicinity of the feeding sheet and in regions for which transonic cross flow velocities are expected a consideration of these various regions with simple methods which account for the observed phenomena leads to substantial improvement in the agreement between theory and experiment it is indicated that the complete vortex wake flow may be adequately predicted for a body of revolution for conditions represented by the theoretical flow model provided that the distribution of the viscous normal force and the vortex locations are accurately known
CRAN	a new theory for the buckling of thin cylinders under axial compression and bending a new theory for the buckling of thin cylinders under axial compression and bending the results of experiments on axial loading of cylindrical shells thin enough to buckle below the elastic limit and too short to buckle as euler columns are not in good agreement with previous theories which have been based on the assumptions of perfect initial shape and infinitesimal deflections experimental failure stresses range from 0 6 to 0 15 of the theoretical the discrepancy is apparently considerably greater for brass and mild steel specimens than for duralumin and increases with the radius  thickness ratio there is an equally great discrepancy between observed and predicted shapes of buckling deflections in this paper an approximate large deflection theory is developed which permits initial eccentricities or deviations from cylindrical shape to be considered true instability is of course impossible under such conditions the stress distribution is no longer uniform and it is assumed that final failure takes place when the maximum stress reaches the yield point the effect of initial eccentricities and of large deflections is much greater than for the case of simple struts measurements of initial eccentricities in actual cylinders have not been made however it is shown that most of these discrepancies can be explained if the initial deviations from cylindrical form are assumed to be resolved into a double harmonic series and if certain reasonable assumptions are made as to the magnitudes of these components of the deviations with these assumptions the failing stress is found to be a function of the yield point as well as of the modulus of elasticity and the radius thickness ratio on the basis of this a tentative design formula 5 is proposel which involves relations suggested by the theory but is based on experimental data it is shown that similar discrepancies between experiments and previous theories on the buckling of thin cylinders in pure bending can be reasonably explained on the same basis and that the maximum bending stress can be taken as about 1 4 times the values given by equation buckling problems can probably be explained by similar considerations and it is hoped that this discussion may help to open a new field in the study of buckling problems the large deflection theory developed in the paper should be useful in exploring this field and may be used in other applications as well the paper presents the results of about a hundred new tests of thin cylinders in axial compression and bending which together with numerous tests by lundquist form the experimental evidence for the conclusions arrived at
CRAN	stability of the cylindrical shell of variable curvature stability of the cylindrical shell of variable curvature the report is a first attempt to devise a calculation method for representing the buckling behavior of cylindrical shells of variable curvature the problem occurs for instance in dimensioning wing noses the stability behavior of which is decisively influenced by the variability of curvature the calculation is made possible by simplifying the stability equations permissible for the shell of small curvature and by assuming that the curvature as a function of the arc length s can be represented by a very few fourier terms we evaluated the formulas for the special case of an ellipse like half oval with an axis ratio under compression in longitudinal direction shear and a combination of shear and compression however the results can also be applied approximately to an unsymmetrical oval shell segment under compression shear and bending so that the numerical values contained in the diagrams 10 to 12 represent directly dimensioning data for the wing nose
CRAN	general theory of large deflections of thin shells with special applications to conical shells general theory of large deflections of thin shells with special applications to conical shells a general theory is developed for the case of large deflections but with rotations of the elements negligible compared to unity the derivation is carried out in tensor form and therefore any coordinate system on the surface of the shell can be used the effect of initial imperfections is included it is shown that for shells of negligible gaussian curvature shallow shells and developable surfaces the problem can be reduced to the solution of two fourth order partial differential equations in a stress function and the deflection normal to the shell for shells forming a surface of revolution the results are indicated in terms of the equation of the generating curve the differential equations for the conical shell are then listed
CRAN	stability equations for conical shells stability equations for conical shells the author rewrites v s vlasovs equations for linear stability theory of shells prikl mat meh 8 1944 109 placements the result is a single eighth order equation for normal deflection and two fourth order equations relating the displacement components in the shell middle surface to the normal displacement
CRAN	buckling of circular cones under axial compression buckling of circular cones under axial compression presented are the results of an experimental investigation to determine the buckling strength of right circular cones under axial compression correlation of these data is made with existing theory and with previously published experimental data on circular cylinders thus a recommended procedure for predicting the buckling load of right circular cones under the foregoing loading condition is presented
CRAN	the characteristics of roughness from insects as observed for two dimensional incompressible flow past airfoils the characteristics of roughness from insects as observed for two dimensional incompressible flow past airfoils advances in the practical development of boundary layer control for the maintenance of extensive laminar flow have drawn attention to the problem of surface roughness due not only to artificial irregularities such as rivet heads lap joints window panels etc but also to the kind generated in flight from impact with insects this natural form of roughening the effects of which have been noted though not investigated previously is the subject of the present paper the phenomenon may be divided into two parts  namely and 2 its effect upon the stability of the laminar boundary layer wind tunnel experiments with the fruit fly drosophila and the common housefly for the investigation of both 1 and airfoils are fully described the former problem has also been treated mathematically in a separate paper not yet published agreement between theory and experiment being satisfactory in all essentials the characteristics of the roughness profile consist principally of a pronounced peak near the leading edge followed by an extensive area of surface over which there is a much reduced and gradually diminishing value of the excrescence height further it is shown that if the severe leading edge roughness or its effect upon the boundary layer can be eliminated then the down stream roughness causes no disturbance to the passage of a laminar layer  i e the surface though roughened is aerodynamically smooth moreover it appears that the conditions defining the upstream boundary to this region of insignificant roughness are fundamentally the same as those which determine the critical state for transition at an artificial disturbance of a three  dimensional character
CRAN	stability of cylindrical and conical shells of circular cross section with simultaneous action of axial compression and external normal pressure stability of cylindrical and conical shells of circular cross section with simultaneous action of axial compression and external normal pressure we consider in this report the determination of the upper limit of critical loads in the case of simultaneous action of a compressive force uniformly distributed over plane cross sections and of isotropic external normal pressure on cylindrical or conical shells of circular cross section as a starting point we use the differential equations for neutral equilibrium of conical shells ref 1 which have been used for the solution of the problem of stability of conical shells under torsion and under axial compression ref 2 upon solution of the problem it is possible to satisfy all boundary conditions in contrast to the report ref 3 where no attention is paid to the fulfillment of the boundary conditions and to the report ref 4 where only part of the boundary conditions are satisfied by solution of the problem according to galerkins method approximate formulas are used for the determination of the critical external normal pressure with simultaneous action of longitudinal compression let us note that the formulas suggested in reference 5 are not well founded and may lead in a number of cases to a substantial mistake in the magnitude of the critical load
CRAN	buckling of thin single  and multi layer conical and cylindrical shells with rotationally symmetric stresses buckling of thin single  and multi layer conical and cylindrical shells with rotationally symmetric stresses the buckling of simply supported thin single  and multi layer conical shells under axially symmetrical loading is analyzed in this paper the results are presented in a compact manner so that they may be easily used for design and or experimental purposes the results are compared with known experimental values
CRAN	a donnell type theory for asymmetrical bending and buckling of thin conical shells a donnell type theory for asymmetrical bending and buckling of thin conical shells equations somewhat more accurate than those recently presented by n j hoff are derived for bending and buckling of thin circular conical shells under arbitrary loading these equations reduce to donnells equations for thin cylindrical shells when the cone semivertex angle becomes very small and the minimum radius of curvature of the median surface approaches a constant value at the other end of the scale the equations reduce to the well known equations for flat circular plates when the cone semivertex angle approaches a right angle in addition for the entire range of cone semivertex angles the equations reduce to the known equations for axisymmetrical bending when variations of the displacements around the circumference vanish the problem of bending is reduced to the solution of a single fourth order partial differential equation with variable coefficients
CRAN	on the buckling of truncated conical shells in torsion on the buckling of truncated conical shells in torsion the problem of the buckling of thin circular conical frustums in pure torsion is solved in a manner similar to that employed previously by the author for buckling under uniform hydrostatic pressure synthesis of the numerical results indicates that the critical torsion of a truncated cone is equal to that of an equivalent cylinder whose length and thickness are the axial length and wall thickness of the cone and whose radius is a function of the semivertex angle and the taper ratio of the cone curves and equations to aid in the analysis of conical frustums are given it is shown that a previous recommendation for the analysis of truncated cones in torsion may be seriously unconservative in some cases
CRAN	calculations for the stability of thin conical frustums subjected to external uniform hydrostatic pressure and axial loads calculations for the stability of thin conical frustums subjected to external uniform hydrostatic pressure and axial loads calculations are presented for the problem of the stability of conical shells subjected to combined external uniform hydrostatic pressure and axial tension or compression stress interaction curves are found to vary only slightly as a function of the ratio of the end radii of the cone
CRAN	some explicit solutions for constant temp magnetogas dynamic channel flow some explicit solutions for constant temp magnetogas dynamic channel flow in order to simplify the process of estimating the aerodynamic loading on the after portions of slender vehicles it is frequently assumed that there is no nose tail interaction it is the purpose of this note to show that aside from boundary layer effects this assumption is not warranted when the nose hypersonic similarity parameter tan is of the order of unity or greater physically speaking the entropy change associated with a strong bow wave reduces the stagnation pressure down stream of the shock and hence lowers the dynamic pressure in the vicinity of the tail
CRAN	of a turbulent free shear layer of a turbulent free shear layer the problem of predicting the mean velocity on streamlines through the pre asymptotic turbulent free shear layer in two dimensional incompressible flow is resolved into two parts the linearized momentum equation in terms of a generalized axial co ordinate is solved in the usual way a relation between and the distance from the separation point is then established analytically in contrast to the previous use of empirical expressions it is shown that except in the region close to separation the velocity on the streamlines can be predicted by the simple approximation proposed by kirk
CRAN	viscous compressible and incompressible flow in slender channels viscous compressible and incompressible flow in slender channels an analytical study is made of viscous flow in slender channels similar solutions to the approximate equations of motion valid for flow at moderate or high reynolds numbers in slender channels are found for incompressible two dimensional and axisymmetric flows and for compressible flows through two dimensional channels with adiabatic walls a study of compressible flows in convergent divergent channels yields results regarding the effect of viscosity on the location of the sonic line on the pressure ratio at the geometric throat and on the discharge coefficient for such channels
CRAN	secondary gas injection in a conical rocket nozzle secondary gas injection in a conical rocket nozzle data are presented on side forces generated by secondary gas injection in a 15 conical rocket exhaust nozzle the side force was measured directly with a force transducer and the data examined in terms of an amplification factor where is the measured effective specific impulse of injectant and is the specific impulse of injectant for sonic flow into a vacuum injection was normal to the axis of the nozzle through a single circular orifice at a fixed point in the diverging portion of the nozzle a variety of ambient temperature gaseous injectants and orifice diameters were carefully studied injectant flow rate was varied for each configuration the main propellant was hot gas catalytically decomposed and motor conditions were held essentially constant
CRAN	compressible free shear layer with finite initial thickness compressible free shear layer with finite initial thickness the momentum equation was uncoupled from the other conservation equations for the case of a finite initial profile in a laminar free shear layer the equation was solved numerically in the crocco coordinate system using an implicit finite difference method profiles of velocity and shear function were obtained as a function of streamwise distance the initial profiles as the flow separates from the rear of the body correspond to the blasius profile in transformed coordinates for large distances downstream the profiles approach the chapman distribution corresponding to the case of zero initial free shear layer thickness the effect of these results on calculations of base pressure and wake angle is discussed a method for the calculation of finite chemical kinetic effects on the profiles of temperature and chemical composition in the free shear layer with finite initial thickness is outlined
CRAN	one dimensional heat conduction through the skin of a vehicle upon entering a planetary atmosphere at constant velocity and entry angle one dimensional heat conduction through the skin of a vehicle upon entering a planetary atmosphere at constant velocity and entry angle closed form solutions of the one dimensional heat conduction equations for the flow of heat into a plate with a laminar boundary layer have been obtained for a configuration entering a planetary atmosphere with constant velocity and negative entry angle the atmospheric density was assumed to obey an exponential law and the temperature was assumed constant initially the solution is in the form of a fourier series expansion which for most practical applications can be approximated by retaining only one term of the expression the solution applies to the initial part of the entry before the maximum heating conditions are encountered
CRAN	method for design of pump impellers using a high speed digital computer method for design of pump impellers using a high speed digital computer a method of designing pump impellers is derived from the equations of motion and continuity for incompressible nonviscous relative flow the flow is assumed to follow a known stream surface representing blade shape that extends from hub to shroud equations are also derived for approximate blade surface velocities and pressures a detailed numerical procedure and block diagram are given for use on a digital computer a numerical example that illustrates limited use of the method is presented and further uses are indicated
CRAN	exploratory investigation of the effect of a forward facing jet on the bow shock of a blunt body in a mach number 6 free stream exploratory investigation of the effect of a forward facing jet on the bow shock of a blunt body in a mach number 6 free stream the effect of a forward facing jet on the bow shock of a blunt body in a mach 6 free stream was investigated experimentally the models tested had forward facing jets using air and helium exhausting at mach numbers from 1 to 10 3 and were run through a range of the ratio of jet total pressure to free stream total pressure of 0 03 jet off to 2 5 the ratio of body diameter to jet exit diameter varied from 1 12 to 55 6 and the angle of attack was varied from 0 to 35 the experimental results show that the main stream shock can be affected by the jet in two significantly different ways one way is simply to move the strong shock away from the body without altering its shape the second and perhaps more interesting case occurs when the jet causes a large displacement of the main shock and considerably changes its shape it was found that the ratio of jet total pressure to free stream total pressure necessary to obtain the large displacements of the main stream shock depended on the ratio of body diameter to jet exit diameter and also on the jet exit mach number the maximum amount the shock could be displaced in percent of body diameter was seen to increase with increasing jet exit mach number and also with decreasing ratio of body diameter to jet exit diameter for the models that were investigated through an angle of attack range the displacement became very unsteady and fell off sharply as the angle of attack was increased simplified theoretical considerations applied to the shock displacement phenomena provide a possible explanation for the two different types of main stream shock displacement theoretical curves show the regions where these types of displacement would occur for different exit mach numbers and pressure ratios for a forward facing jet in a mach 6 stream
CRAN	static aerodynamic characteristics of a short blunt 10 semi vertex angle cone at a mach number of 15 in helium static aerodynamic characteristics of a short blunt 10 semi vertex angle cone at a mach number of 15 in helium axial force normal force pitching moment and shock wave shape were determined for a body of revolution consisting of a short blunt 10 semivertex angle cone with a flat base and also with a conical afterbody having a semi vertex angle of 50 measurements were made in helium at a free stream mach number of 15 and a free stream reynolds number of 2 25x10 based on maximum body diameter over an angle of attack range from the configuration with the conical afterbody was statically stable in the nose forward attitude only whereas the configuration with no afterbody was statically stable in both the nose forward and base forward attitudes the force and moment data of both shapes were predicted reasonably well by modified newtonian theory at all angles of attack except the pitching moment coefficient for the model without afterbody near 180 angle of attack in this region measurements indicated static stability whereas theory indicated static instability the helium data agreed reasonably well with a limited amount of force and moment data obtained in a ballistic range at small angles of attack in air at a mach number of 15 and also with force and moment data obtained in air over a complete angle of attack range at a mach number of 5 5 the value of axial force coefficient and the shape of the bow shock wave at zero angle of attack for both models obtained from a numerical flow field calculation agreed very well with the data the value of the axial force coefficient at 180 angle of attack for the model with afterbody agreed reasonably well with the theoretical value for a cone the position and shape of the shock envelope near the stagnation point also could be predicted accurately by an approximate method over an angle of attack range from
CRAN	panel flutter tests on full scale x 15 lower vertical stabilizer at mach number of 3 0 panel flutter tests on full scale x 15 lower vertical stabilizer at mach number of 3 0 panel flutter tests were conducted on two full scale vertical stabilizers of the x 15 airplane at a mach number of 3 0 in the langley at dynamic pressures from 1 500 psf to 5 000 psf and stagnation temperatures from 300 f to 660 f flutter boundaries were obtained for four of the five distinct types of panels which make up the vertical sides of the stabilizers the boundaries consisted of a flat panel boundary and a thermally buckled panel boundary the flat panel boundaries were characterized by a reduction in dynamic pressure with increasing skin temperature whereas after thermal buckling the trend was reversed the minimum dynamic pressure for flutter occurred at the intersection of the flat panel and buckled panel boundaries and represented a large reduction in the dynamic pressure over the extrapolated unstressed value as a result of panel flutter three of the five distinct types of panels were modified to provide the required flutter margin on the design flight dynamic pressure of the aircraft
CRAN	charts for equilibrium flow properties of air in hyper velocity nozzles charts for equilibrium flow properties of air in hyper velocity nozzles for initial stagnation pressures up to 1 000 atmospheres and stagnation enthalpies up to 10 000 btu per pound nozzle flow properties for equilibrium air have been computed and plotted on charts the work of nasa tn d 693 has been extended to include flow properties for closer intervals of specified stagnation enthalpies properties which have been charted as a function of mach number are as follows temperature pressure density velocity area ratio dynamic pressure reynolds number isentropic exponent and molecular weight ratio ratios of temperature pressure and density across normal shock waves are also charted and weight flow rate is plotted as a function of stagnation enthalpy
CRAN	comparison of theoretical and experimental creep buckling times of initially straight centrally loaded columns comparison of theoretical and experimental creep buckling times of initially straight centrally loaded columns the creep buckling times of initially straight centrally loaded columns as predicted by the hypotheses of shanley gerard and rabotnov and shesterikov are compared with appropriate experimental data it is found that the theoretical predictions are generally conservative due possibly to the fact that the hypotheses predict initial instability times while the experiments normally record final collapse times of the three hypotheses that of gerard generally gives predictions which agree best with the experimental data
CRAN	a unified theory of creep buckling under normal loads a unified theory of creep buckling under normal loads a general theory of creep buckling with the initial imperfection as a parameter is developed for the case of normal loading a hyperbolic sine law is used to describe the process of creep the theory is believed to be applicable to among other structures columns tubes and possibly conical shells the wall of the structure is idealized as a sandwich in order to simplify the integration of the equations experimental data on columns and tubes from two different sources are compared with the predictions of the theory
CRAN	study of creep collapse of a long circular cylindrical shell under various distributed force systems study of creep collapse of a long circular cylindrical shell under various distributed force systems an analysis is presented for determining the collapse of circular rings and long cylinders subjected to primary and secondary creep conditions at elevated temperatures the types of loading considered for the present investigation are dead loading and hydrostatic pressure type forces the method of solution is based on an application of the variational theorem for creep described in ref 1 with some additional terms being introduced for the pressure type loading case the general results are reduced to a relatively simple form for the theoretical predictions of collapse time and are graphically illustrated for a typical sample material
CRAN	vibrations of infinitely long cylindrical shells under initial stress vibrations of infinitely long cylindrical shells under initial stress the general bending theory of shells under the influence of initial stress presented recently by herrmann and armenakas is applied in this investigation to study the effect of initial uniform circumferential stress uniform bending moment and uniform radial shear on the dynamic response of an infinitely long cylindrical shell
CRAN	analysis of stress at several junctions in pressurized shells analysis of stress at several junctions in pressurized shells theoretical and experimental results are presented for the discontinuity stresses arising at a change of wall thickness in a cylinder a cylinder hemisphere junction and a cone spherical torus junction in pressure vessels the effect of mismatch of nonconcurrence of the middle surfaces of two joined cylinders is considered in addition a cylinder with a special closure which has considerably reduced stresses is described and curves with theoretical and experimental stresses are presented
CRAN	the membrane approach to bending instability of pressureized cylindrical shells the membrane approach to bending instability of pressureized cylindrical shells recent theoretical and experimental research is briefly described to trace the development of deformation and the occurrence of collapse in pressurized circular cylindrical membranes under applied moment loading the collapse of pure membrane cylinders is then compared with instability of pressurized cylindrical shells this approach leads to a better understanding of the behavior of pressurized cylinders under bending loads the results suggest possibilities for further research utilizing the membrane approach
CRAN	elastic stability of simply supported corrugated core sand  wich cylinders elastic stability of simply supported corrugated core sand  wich cylinders theoretical buckling coefficients are obtained for the general instability of simply supported corrugated core sandwich circular cylinders under combined loads with the core oriented parallel to the longitudinal axis of the cylinder buckling curves are presented for axial compression external lateral pressure torsion and some typical interactions the differential equations of equilibrium used to obtain the buckling equations were derived from the small deflection equations of stein and mayer which include the effect of deformation due to transverse shear these equations are solved by galerkins equation remarks are made concerning the probable validity of the results of the small deflection theory for sandwich shells
CRAN	axisymmetric snap buckling of conical shells axisymmetric snap buckling of conical shells the authors give a brief account of some of their recent analytical and numerical studies of cone buckling limiting the discussion to axisymmetric deformations pertinent numerical results for the relaxation buckling of full cones subjected to uniform external pressure and belleville springs deformed by axial edge loads are presented in addition bifurcation buckling problems are discussed for a specific case the existence of friedrichs intermediate buckling load as applied to cones is established upper and lower bounds for its value are given
CRAN	air scooping vehicle air scooping vehicle a satellite vehicle is described which collects gases from the upper atmosphere and stores them in liquid form such a vehicle could serve as a filling station in space furnishing liquid oxygen or air to other spacecraft the vehicle represents an alternative to launching these liquids into orbit from the surface of the earth the two methods are compared on an economic basis and it is shown that the proposed vehicle permits substantial savings when operated beyond about one year the feasibility of developing such a system for long time operation is investigated several practical designs are discussed
CRAN	heat transfer in separated flows heat transfer in separated flows results of an experimental heat transfer investigation in regions of separated flow are presented and compared with the theoretical analysis of naca tn 3792 the average heat transfer for both laminar and turbulent separated boundary layers was found to be from 35 to 50 per cent less than that for equivalent attached boundary layers the overall scope of the measurements included mach numbers from 0 3 to 4 0 and reynolds numbers from 10 to 4 x 10 the results for laminar boundary layers agree well with the analysis of tn 3792 the results for turbulent boundary layers however disagree considerably results of velocity and temperature surveys in the separated turbulent boundary layer are presented and partially explain the discrepancy between the experiments and analysis the maximum local heat transfer rates were found to occur in the reattachment region of the separated boundary layers investigated the effect of transition on heat transfer in the separated laminar boundary layers is described and data showing effects of mach number and wall temperature on the transition reynolds number of separated laminar flows are also included
CRAN	investigation of free turbulent mixing investigation of free turbulent mixing a discussion of the integral relations for flow of the boundary layer type is presented it is shown that the characteristic laws of spread of jets wakes and so forth can be obtained directly for the laminar case and with the help of dimensional reasoning for the turbulent case as well measurements of the mean velocity the intensity and scale of the turbulent fluctuations and of the turbulent shear in a two dimensional mixing zone are presented the results of these measurements are compared with the mixing length theories it is shown that both mixing length and exchange coefficient vary across the mixing zone the theories based on the assumption of constant mixing length or exchange coefficient are thus in error a discussion of the energy balance of the fluctuating motion is given and the triple correlation is estimated
CRAN	compressible two dimensional jet mixing at constant pressure compressible two dimensional jet mixing at constant pressure an analysis is made of turbulent constant pressure mixing for a compressible jet boundary taking into consideration effects of the initial boundary layer velocity profiles in the mixing region are represented in a transformed plans by one parameter families of curves with no specification for the mixing mechanism beyond that of an exchange coefficient concept being made the exchange coefficient is represented by the bornel function of an integral transform for the x coordinate of an intrinsic system of coordinates this intrinsic system and the physical coordinate system are related by means of a momentum integral satisfactory correlation of theory and experimental low speed data is obtained with a simple form of kernal function an asymptotic solution corresponding to a fully developed velocity profile in the jet boundary allows the calculation of the mechanical energy level along the separating streamline in the jet boundary without the use of empirical information
CRAN	contributions to the theory of heat transfer through a laminar boundary layer contributions to the theory of heat transfer through a laminar boundary layer an approximation to the heat transfer rate across a laminar incompressible boundary layer for arbitrary distribution of main stream velocity and of wall temperature is obtained by using the energy equation in von misess form and approximating the coefficients in a manner which is most closely correct near the surface the heat transfer rate to a portion of surface of length l breadth is given as where k is the thermal conductivity of the fluid o its prandtl number p its density u its viscosity r x is the skin friction and t x the excess of wall temperature over main stream temperature a critical appraisement of the formula indicates that it should be very accurate for large but that for of order 0 7 for most gases the constant should be replaced by 0 73 when the error should not exceed this yields a formula for nusselt number in terms of the reynolds number r and the mean square root of the skin friction coefficient c in the case of uniform wall temperature however for the boundary layer with uniform main stream the original formula is accurate to within 3 percent even for by known transformations an expression is deducted for heat transfer to a surface with arbitrary temperature distribution along it and with a uniform stream outside it at arbitrary mach number equation 42 from this the temperature distribution along such a surface is deduced in the case of importance at high mach numbers when heat transfer to it is balanced entirely by radiation from it this calculation which includes the solution of a non linear integral equation gives higher temperatures near the nose and lower ones farther back figure 2 than are found from a theory which assumes the wall temperature uniform and averages the heat transfer balance this effect will be considerably mitigated for bodies of high thermal conductivity the author is not in a position to say whether or not it will be appreciable for metal projectiles but for stony meteorites at a certain stage of their flight through the atmosphere it indicates that melting at the nose and re solidification farther back may occur for which the shape and constitution of a few of them affords evidence an appendix shows how the method for approximating and solving von misess equation could be used to determine the skin friction as well as heat transfer rate but this line seems to have no advantage over established approximate methods
CRAN	a variational principle for convection of heat a variational principle for convection of heat authors extend variational principle of biot to various cases of heat transfer due to forced convection numerical results are given for one dimensional problems of fluid flowing between parallel walls with uniform or parabolic velocity profiles agreement with exact solutions is excellent
CRAN	on the theory of discharge coefficients for round entrance flowmeters and venturis on the theory of discharge coefficients for round entrance flowmeters and venturis a theory of rounded entrance flowmeters based on a consideration of the potential and boundary layer flows in a converging nozzle is constructed curves are presented showing the discharge coefficient as a function of diameter reynolds number with the total equivalent length tional length diameter ratio of the contraction section of the asme long radius nozzle is presented the theoretical curves of discharge coefficient versus diameter reynolds number are in good agreement with experiment over a range of reynolds number from 1 to 10 the theory provides a rational framework for correlating and extrapolating experimental results it shows the effects of contraction shape and location of pressure taps it furnishes values of discharge coefficient for untested designs and it suggests precautions to be taken in design installation and operation
CRAN	analytic determination of discharge coefficients of flow nozzles analytic determination of discharge coefficients of flow nozzles integration of the velocity profile at the throat of a flow nozzle yields the discharge coefficient as a function of the ratio of boundary solution of the approximate momentum equation for the boundary layer the resulting expression for the discharge coefficient is then a function of the reynolds number based on nozzle diameter and of the geometry of the nozzle good agreement is shown between this expression and published experimental data on flow nozzles for reynolds numbers between
CRAN	on fully developed channel flows some solutions and limitations and effects of compressibility variable properties and body forces on fully developed channel flows some solutions and limitations and effects of compressibility variable properties and body forces an examination of the effects of compressibility variable properties and body forces on fully developed laminar flows has indicated several limitations on such streams in the absence of a pressure gradient but presence of a body force liquid this follows also for the case of a constant streamwise pressure gradient these motions are exact in the sense of a couette flow in the liquid case two solutions not a new result can occur for the same boundary conditions an approximate analytic solution was found which agrees closely with machine calculations in the case of approximately exact flows it turns out that for large temperature variations across the channel the effects of convection due to say a wall temperature gradient and frictional heating must be negligible in such a case the energy and momentum equations are separated and the solutions are readily obtained if the temperature variations are small then both convection effects and frictional heating can consistently be considered this case becomes the constant property incompressible case or quasi incompressible case for free convection flows considered by many authors finally there is a brief discussion of cases wherein streamwise variations of all quantities are allowed but only in such form that the independent variables are separable for the case where the streamwise velocity varies inversely as the square root of distance along the channel a solution is given
CRAN	a study of laminar compressible viscous pipe flow accelerated by an axial body force with application to magnetogasdynamics a study of laminar compressible viscous pipe flow accelerated by an axial body force with application to magnetogasdynamics a study is made of the steady laminar flow of a compressible viscous fluid in a circular pipe when the fluid is accelerated by an axial body force the application of the theory to the magnetofluidmechanics of an electrically conducting gas accelerated by electric and magnetic fields is discussed constant viscosity thermal conductivity and electrical conductivity are assumed fully developed flow velocity and temperature profiles are shown and detailed results of the accelerating flow development including velocity and pressure as functions of distance are given for the case where the axial body force is constant and for the case where it is a linear function of velocity from these results are determined the pipe entry length and the pressure difference required
CRAN	rocket propulsion systems for interplanetary flight rocket propulsion systems for interplanetary flight a comparison is made of several different propulsion systems for interplanetary flight liquid and solid propellant rockets propulsion systems which use nuclear energy sources are heating rockets magneto plasma devices ion rocket propulsion solar heating rockets and solar sails are briefly described and their current status reviewed engine performance requirements for different interplanetary missions are established these several propulsion systems are then compared on the basis of several performance criteria environmental characteristics vehicle requirements reliability current status growth potential and efficiency predictions on various propulsion system capabilities and an analysis of multiple rocket engine reliability is included it is concluded that electrical rockets are superior for long time inter planetary flight applications and that chemical rockets are satisfactory for most of the immediate applications in near space none of the several propulsion schemes discussed can be rejected until further technical work has been accomplished
CRAN	on the use of side jets as control devices on the use of side jets as control devices wind tunnel experiments with side jets issuing laterally near the base of slender bodies in a supersonic stream have suggested the existence of a sizable and usable interaction with this interaction force the use of jet reaction controls may be as attractive for flight within the atmosphere as it obviously is for flight outside the atmosphere this note indicates the altitude regime of interest and the order of magnitude of the interaction bonus for a lateral control jet located near the base of a body of revolution
CRAN	loads induced on a flat plate wing by an air jet exhausting perpendicularly through the wing and normal to a free stream flow of mach number 2 0 loads induced on a flat plate wing by an air jet exhausting perpendicularly through the wing and normal to a free stream flow of mach number 2 0 measurements were made of loads induced on a flat plate wing by an air jet exhausting perpendicularly through the wing and normal to the free stream flow the investigation was conducted at a free stream mach number of 2 0 and a reynolds number per foot of 14 4 x 10 an axially symmetric sonic nozzle and two supersonic nozzles were employed for the jets the supersonic nozzles consisted of an axially symmetric nozzle with exit mach number of 3 44 and a two dimensional nozzle with exit mach number of 1 76 the ratio of nozzle total pressure to free stream static pressure was varied from 20 to 110 negative loads were induced on the flat plate wing by all the jets as the nozzle pressure ratio was increased the magnitude of interference loads due to jet thrust decreased the chordwise center of pressure location generally moved toward the nozzle center line as the pressure ratio was increased
CRAN	surface pressure distributions with a sonic jet normal to adjacent flat surfaces at mach 2 92 to 6 4 surface pressure distributions with a sonic jet normal to adjacent flat surfaces at mach 2 92 to 6 4 an investigation was made to determine the interference effects on surface pressure distributions caused by a sonic jet exiting normal to the surface two configurations a flat plate and an arrow wing reentry type vehicle with sonic nozzles near the leading edge were tested over a range of pressure ratios and reynolds numbers for mach numbers from the data indicate that jet pressure ratio had considerable effect on the pressure levels and distributions on both configurations also for a constant jet pressure ratio the free stream mach number effect on the distributions and levels was quite large over the limited range investigated the effect of reynolds number at constant mach number and pressure ratio was small compared to the mach number and pressure ratio effect
CRAN	aerodynamic interaction effects ahead of a sonic jet exhausting perpendicularly form a flat plate into a mach number 6 free stream aerodynamic interaction effects ahead of a sonic jet exhausting perpendicularly form a flat plate into a mach number 6 free stream an investigation of the effects of the interaction ahead of a two dimensional sonic jet exhausting perpendicularly into a mach number were made at an angle of attack of 0degree at a reynolds number per foot of approximately 6 x 10 and with conditions of both transitional and turbulent separation on the flat plate the ratio of jet stagnation pressure to free stream static pressure was varied from 8 to 460 and the jet slot width was varied from 0 001 to 0 05 inch the force ratio due to reaction of jet calculated ahead of the jet was sizable and varied from 0 5 to 9 in general the ratio increased with increasing pressure ratio and decreasing slot width for the turbulent boundary layer separation tests it was found that the first peak pressure and the chordwise pressure distribution of the separated boundary layer ahead of the jet were similar to those for a separation caused by a forward facing step at the same test conditions
CRAN	interaction effects produced by jet exhausting laterally near base of ogive cylinder model in supersonic main stream interaction effects produced by jet exhausting laterally near base of ogive cylinder model in supersonic main stream the experimentally determined interaction effects of a side jet exhausting near the base of an ogive cylinder model are presented and discussed the interaction force appears to be independent of main stream mach number boundary layer condition laminar or turbulent angle of attack and forebody length the ratio of interaction force to jet force is found to be inversely proportional to the square root of the product of jet stagnation to free stream pressure ratio and jet to  body diameter ratio
CRAN	approximate analysis of thrust vector control by fluid injection approximate analysis of thrust vector control by fluid injection a study has been made of the side force generated by injection of secondary material into the main stream of a rocket nozzle two cases have been analyzed gas injection and liquid injection for the gas injection case it is assumed that the turbulent boundary layer ahead of the injection point separates from the wall the pressure in the separated region and the extent of the separated region are determined by a consideration of turbulent boundary layer shock wave interaction and the accommodation height of the injected gas stream equations are derived for calculating the side force and the side forces predicted by the theory are compared with experimental data the agreement between theory and experiment is fair for the case of liquid injection it is assumed that the liquid flows along the nozzle wall and evaporates into the main stream the resulting side force on the nozzle wall is determined on the basis of linearized theory thus restricting the analysis to small rates of liquid injection the effects of small rates of heat addition are also included in the analysis a very simple equation for calculating the side force is obtained
CRAN	one dimensional flows of an imperfect diatomic gas one dimensional flows of an imperfect diatomic gas with the assumptions that berthelots equation of state accounts for molecular size and intermolecular force effects and that changes in the vibrational heat capacities are given by a planck term expressions are developed for analyzing one dimensional flows of a diatomic gas the special cases of flow through normal and oblique shocks in free air at sea level are investigated it is found that up to a mach number of 10 the pressure ratio across a normal shock differs by less than 6 percent from its ideal gas value whereas at mach numbers above 4 the temperature rise is considerably below and hence the density rise is well above that predicted assuming ideal gas behavior it is further shown that only the caloric imperfection in air has an appreciable effect on the pressures developed in the shock process considered the effects of gaseous imperfections on oblique shock flows are studied from the standpoint of their influence on the lift and pressure drag of a flat plate operating at mach numbers of 10 and 20 the influence is found to be small
CRAN	turbulent diffusion in the wake of a blunt nosed body at hypersonic speeds turbulent diffusion in the wake of a blunt nosed body at hypersonic speeds at reynolds numbers greater than about 5 x 10 corresponding to altitudes below about 180 000 ft the hot outer inviscid wake behind the bow shock wave produced by a blunt nosed body at hypersonic speeds is cooled mainly by turbulent diffusion and conduction turbulence originates in the inner wake formed by the coalescence of the free shear layers or annulus shed from the body surface when the boundary layer separates from the surface as this turbulence spreads outward it swallows enthalpy or momentum defect originally contained in the outer inviscid wake if the turbulence is locally similar  i e if it behaves at each station like a slice of a low speed self similar wake  then the turbulent diffusivity grows from a low initial value near the body to a value corresponding to the total drag of the body at about 300 body diameters downstream at flight velocities of the order of 9 000 10 000 ft per sec the growth of the turbulent inner wake predicted on the basis of locally similar turbulence is in good agreement with shadowgraph measurements of wake widths behind spheres obtained in ballistic ranges in the region from 200 to 4 000 body diameters downstream of the body tentatively one concludes that the turbulence mechanism in the wake with respect to a fixed observer is similar to the low speed case in spite of the large mean temperature gradients in order to illustrate the behavior of an observable such as electron density in a turbulent wake behind a blunt body the two limiting cases of thermodynamic equilibrium and pure diffusion zero electron ion recombination rate are calculated for m 22 at altitudes of 100 000 and 200 000 ft even for the case of thermodynamic equilibrium the predicted turbulent radar trail length is about 200 body diameters at l band 1 300 mc at 100 000 ft altitude and about 150 body diameters for uhf 400 mc at 200 000 ft one interesting result is that the width of the plasma cylinder corresponding to the plasma requency at l band remains virtually constant at about 3 5 body diameters in the range 30 150 at 100 000 ft altitude these results are sufficiently encouraging that one can consider including the effects of finite chemical and electron ion recombination rates in the analysis in order to give a more complete picture of the wake at hypersonic speeds
CRAN	concerning some solutions of the boundary layer equations in hydrodynamics concerning some solutions of the boundary layer equations in hydrodynamics the boundary layer equations for a steady two dimensional motion are solved for any given initial velocity distribution distribution along a normal to the boundary wall downstream of which the motion is to be calculated this initial velocity distribution is assumed expressible as a polynomial in the distance from the wall three cases are considered first when in the initial distribution the velocity vanishes at the wall but its gradient along the normal does not second when the velocity in the initial distribution does not vanish at the wall and third when both the velocity and its normal gradient vanish at the wall as at a point where the forward flow separates from the boundary the solution is found as a power series in some fractional power of the distance along the wall whose coefficients are functions of the distance from the wall to be found from ordinary differential equations some progress is made in the numerical calculation of these coefficients especially in the first case the main object was to find means for a step by step calculation of the velocity field in a boundary layer and it is thought that such a procedure may possibly be successful even if laborious the same mathematical method is used to calculate the flow behind a flat plate along a stream the results are shown in curves in the original
CRAN	temperature profiles inafinite solid with moving boundary temperature profiles inafinite solid with moving boundary a numerical solution is presented to the transient heat conduction equation for a cylinder of finite thickness with one moving boundary the implicit method of solution is developed with conductivity as an arbitrary function of temperature application is made to a sample case of re entry heating encountered by aerodynamic bodies with erosion by sublimation and combustion occurring at the body surface
CRAN	correlation of base pressure and wake structure of sharp and blunt nose cones with reynolds number based on boundary layer momentum thickness correlation of base pressure and wake structure of sharp and blunt nose cones with reynolds number based on boundary layer momentum thickness it has been established in the past that there is a certain relationship between base pressure and boundary layer behavior the base pressure and wake flow conditions were found to be dependent upon the local flow characteristics at the surface of supersonic vehicles directly upstream of the base or of the region of wake flow separation in order to use existing data on cones and other shapes to predict wake angle and base pressure on blunt bodies an attempt was made recently at the naval ordnance laboratory to establish a unique relationship between given local flow conditions at the downstream end of sharp and blunt cones at supersonic speeds and the corresponding wake flow conditions with zero heat transfer
CRAN	a method of computing the transient temperature of thick walls from arbitrary variation of adiabatic wall temperature and heat transfer coefficient a method of computing the transient temperature of thick walls from arbitrary variation of adiabatic wall temperature and heat transfer coefficient a method of calculating the temperature of thick walls has been developed in which are used relatively new concepts such as the time series and the response to a unit triangle variation of surface temperature together with essentially standard formulas for transient temperature and heat flow into thick walls the method can be used without knowledge of the mathematical tools of its development the method is particularly suitable for determining the wall temperature in one dimensional thermal problems in aeronautics where there is a continuous variation of the heat transfer coefficient and adiabatic wall temperature the method also offers a convenient means for solving the inverse problem of determining the heat flow history when temperature history is known a series of diversified problems were solved by exact analysis as well as by the new method a comparison of the results shows the new method to be accurate the labor involved is very modest in consideration of the nature of the thick wall temperature problem limiting solutions for the infinitely thick wall and for walls so thin that thermal lag can be neglected were also obtained
CRAN	solutions to the heat conduction equation with time dependent boundary conditions solutions to the heat conduction equation with time dependent boundary conditions design charts based on the analytical solution to the problem of one dimensional heat flow in a solid body of constant material properties with time dependent boundary conditions were presented by kaye and yeh this solution dealt with aerodynamic heating at hypersonic speeds where the surface coefficient of heat transfer and the temperature potential were taken to be linear functions of time of flight in order to make these charts of more general application general solutions are presented which together with the charts enable rapid and reasonable estimates to be made of the transient temperature distributions in many practical cases
CRAN	the temperature history in a thick skin subjected to laminar heating during entry into the atmosphere the temperature history in a thick skin subjected to laminar heating during entry into the atmosphere during high speed entry into the earths atmosphere a vehicle can be afforded thermal protection for the short period of entry heating by a thick outer skin sometimes called a heat sink the temperature distribution in such a heat sink has been found by integrating the product of the laminar aerodynamic heating rate and the appropriate greens function for a finite thickness wall over the generalized trajectory for a vehicle entering the earths atmosphere at high speeds dimensional heat conduction problem for laminar heating the maximum surface temperature that occurs during the generalized entry trajectory for any combination of wall thickness and thermal properties is obtained from which the performance of any material can be found provided that the average thermal properties may be used as an example of the use of the solution the performance of copper graphite molybdenum and tungsten are compared
CRAN	addendum to heat transfer to satellite vehicles re entering the atmosphere addendum to heat transfer to satellite vehicles re entering the atmosphere the original paper gave a correlation formula for stagnation point heat transfer rate to a blunt body of revolution in hypersonic flow this note gives a somewhat refined version based on further calculation and shock tube data its effect on the conclusions of the original paper is negligible except at surface temperature parameters of over 5000 r ft1 8 in other problems where heat transfer rate itself is important it can make a significant defference
CRAN	method of analysis for compressible flow through mixed flow centrifugal impellers of arbitrary design method of analysis for compressible flow through mixed flow centrifugal impellers of arbitrary design a method is presented for analysis of the compressible flow between the hub and the shroud of mixed flow impellers of arbitrary design axial symmetry was assumed but the forces in the meridional hub to shroud plane which are derived from tangential pressure gradients were taken into account the method was applied to an experimental mixed flow impeller the analysis of the flow in the meridional plane of the impeller showed that the rotational forces the blade curvature and the hub shroud profile can introduce severe velocity gradients along the hub and the shroud surfaces choked flow at the impeller inlet as determined by the analysis was verified by experimental results
CRAN	a rapid approximate method for the design of hub shroud profiles of centrifugal impellers of given blade shape a rapid approximate method for the design of hub shroud profiles of centrifugal impellers of given blade shape a rapid approximate method for the design of centrifugal compressors of given blade shape with compressible nonviscous flow characteristics has been developed using techniques based upon stream filament theory axial symmetry is assumed but meridional plane forces derived from tangential pressure gradients are included the method was applied to the design of an impeller in order to determine the approximate maximum meridional streamline spacing that could be used three numerical solutions for different streamline spacings were made using the same hub profile blade shape and prescribed velocity distribution along the hub the shroud profiles obtained from the three solutions which utilized 3 5 and 9 stream tubes were negligibly different the approximate computing time required was 15 hours per streamtube
CRAN	design and test of mixed flow impellers viii   comparison of experimental results for three impellers with shroud redesigned by rapid approximate method design and test of mixed flow impellers viii   comparison of experimental results for three impellers with shroud redesigned by rapid approximate method three centrifugal impellers with parabolic circular and skewed parabolic blading were modified by a recently developed design procedure to reduce the velocity gradients along the hub from inlet to outlet all original dimensions except the shroud contours were retained experimental investigation showed that the modified impellers had better performance characteristics than the original impellers at all speeds investigated the greatest gains occurring at speeds of 1300 feet per second and higher these large gains probably resulted primarily from more favorable velocity gradients and from designing these impellers further away from the condition necessary for eddy formation the modified impellers were thus able to operate over a wider range of weight flows at high speeds the modified impellers were investigated over a range of equivalent speeds of 900 to 1500 feet per second and flow rates from maximum to the point of incipient surge at 1300 feet per second the peak pressure ratio and maximum adiabatic temperature rise efficiency for the parabolic bladed impeller were 3 07 and 0 825 respectively for the same conditions the circular bladed impeller and the skewed parabolic bladed impeller had pressure ratios of 3 13 and 3 15 and efficiencies of 0 737 and 0 805 respectively of the three the parabolic bladed impeller had the highest maximum efficiencies 0 854 to 0 800 and the best weight flow range over the speed range tested on the basis of the parameters investigated it appears that parabolic blading is superior to circular blading the experimental results indicate that the design method of naca tn 3399 is a reliable method for use in designing centrifugal impellers
CRAN	a general theory of three dimensional flow in subsonic and supersonic turbo machines of axial radial and mixed flow types a general theory of three dimensional flow in subsonic and supersonic turbo machines of axial radial and mixed flow types a general theory of steady three dimensional flow of a nonviscous fluid in subsonic and supersonic turbomachines having arbitrary hub and casing shapes and a finite number of blades is presented the solution of the three dimensional direct and inverse problem is obtained by investigating an appropriate combination of flows on relative stream surfaces whose intersections with a z plane either upstream of or somewhere inside the blade row form a circular arc or a radial line the equations obtained to describe the fluid flow on these stream surfaces show clearly the several approximations involved in ordinary two dimensional treatments they also lead to a solution of the three dimensional problem in a mathematically two dimensional manner through iteration the equation of continuity is combined with the equation of motion in either the tangential or the radial direction through the use of a stream function defined on the surface and the resulting equation is chosen as the principal equation for such flows the character of this equation depends on the relative magnitude of the local velocity of sound and a certain combination of velocity components of the fluid a general method to solve this equation by both hand and high speed digital machine computations when the equation is elliptic or hyperbolic is described the theory is applicable to both irrotational and rotational absolute flow at the inlet of the blade row and at both design and off design operations
CRAN	nonviscous flow through a pump impeller on a blade to blade surface of revolution nonviscous flow through a pump impeller on a blade to blade surface of revolution the nonviscous incompressible flow through a typical pump impeller is analyzed on a blade to blade surface of revolution solutions are obtained for a variety of inlet conditions including several with prewhirl of the assumed location of the rear stagnation point comparison of results from two approximate methods of analysis showed good agreement for the zero angle of attack case and reliable indication of the existence of an eddy on the driving face at a large positive angle of attack
CRAN	incompressible nonviscous blade to blade flow through a pump rotor with splitter vanes incompressible nonviscous blade to blade flow through a pump rotor with splitter vanes the nonviscous flow through a mixed flow pump impeller having one splitter vane between adjacent main blades has been analyzed on a blade to blade surface of revolution using a previously reported analysis method solutions were obtained for a variety of flow conditions including several cases in which whirl is imparted to the flow upstream of the impeller the velocity distributions on the main blade surfaces and on the splitter vane surfaces in the region of the splitter vane were strongly dependent on the assumed location of the rear stagnation points solutions were obtained by assuming values of slip factor and of division of flow around the splitter in addition to assuming the location of the rear stagnation points these solutions indicated that the velocity distributions in the splitter vane region are largely determined by the division of flow around the splitter vane and that only the region in the immediate vicinity of the trailing edge is affected by the slip factor blade surface velocities were obtained from two approximate methods by specifying flow division and slip factor and these results are compared with the more exact solutions of the analysis
CRAN	a rapid approximate method for determining velocity distribution on impeller blades of centrifugal compressors a rapid approximate method for determining velocity distribution on impeller blades of centrifugal compressors a rapid approximate method of analysis was developed for both compressible and incompressible nonviscous flow through radial  or mixed flow centrifugal compressors with arbitrary hub and shroud contours and with arbitrary blade shape the method of analysis is used to determine approximately the velocities everywhere along the blade surfaces but no information concerning the variation in velocity across the passage between blades is given in eight numerical examples for two dimensional flow covering a fairly wide range of flow rate impeller tip speed number of blades and blade curvature the velocity distribution along the blade surfaces was obtained by the approximate method of analysis and compared with the velocities obtained by relaxation methods in all cases the agreement between the approximate solutions and the relaxation solutions was satisfactory except at the impeller tip where the velocities obtained by the approximate method did not in general become equal on both surfaces of the blade as required by the joukowski condition
CRAN	wing flow study of pressure drag reduction at transonic speed by projecting a jet of air from the nose of a prolate spheroid of fineness ratio 6 wing flow study of pressure drag reduction at transonic speed by projecting a jet of air from the nose of a prolate spheroid of fineness ratio 6 a study was made at transonic speeds by the naca wing flow method of the pressure drag reduction obtained by projecting a high energy jet of air from the nose of a prolate spheroid supplementary information was obtained by taking shadowgraphs of the model mounted in a small supersonic tunnel at a constant mach number of 1 5 the high velocity jet was observed to alter the pressure distribution over the body in such a way that the pressure drag of the body was reduced thus in a restricted sense the nose jet produced a thrust on the body under the conditions investigated the thrust produced by the nose jet was never so large as that which would be expected from a conventional rearward jet for example under the best conditions tested mach number of 1 07 the reduction in body pressure drag caused by the nose jet more than compensated for the negative thrust of the jet itself however the magnitude of the net reduction in drag change in body pressure drag with jet on and jet off minus the adverse thrust of the jet was only about one half of the thrust which would be produced by the same jet exhausting rearward the appearance of such an unexpectedly large effect in the first trial indicated the phenomenon to be worth further study
CRAN	the effects of a small jet of air exhausting from the nose of a body of revolution in supersonic flow the effects of a small jet of air exhausting from the nose of a body of revolution in supersonic flow an investigation has been made at a mach number of 1 62 to determine the effects of a small jet of air exhausting from the nose of an elliptical body of revolution upon boundary layer transition and the viscous pressure and total drag of the forebody at three body stations body nose were also obtained the tests were conducted at reynolds numbers of 2 13 x 10 and 7 66 x 10 based on body length the maximum range of thrust coefficients for the small jet was from 0 to about at the lower test reynolds number for which the boundary layer was laminar over the entire body in the jet off condition a very small flow from the jet moved the point of transition forward to the vicinity of the 20 percent body station as the jet flow was increased the transition point moved abruptly to the nose at a thrust coefficient of about gardless of the type of boundary layer at the higher test reynolds number for which the boundary layer was largely turbulent in the jet off condition the total drag including skin friction was reduced somewhat by the action of the jet although the forward exhausting small jet was found to have the above favorable effects upon the drag these findings are not believed too important since the question arises as to the benefits of the same small jet exhausting from the rear of the body in the conventional manner no attempt was made to establish geometric optimums in the present investigation yet from a general consideration of the benefits indicated by the present results and the phenomena known to occur in the vicinity of rearward exhausting jets the benefits of a small jet exhausting rearward would appear to exceed those of the same small jet exhausting forward particularly so when the flow over the body is laminar in the jet off condition
CRAN	the extent of the jet interference flow fields jet effects on cylindrical afterbodies housing sonic and supersonic nozzles which exhaust against a supersonic stream at angles of attack from 90degree to 180degree the extent of the jet interference flow fields jet effects on cylindrical afterbodies housing sonic and supersonic nozzles which exhaust against a supersonic stream at angles of attack from 90degree to 180degree an investigation has been made to determine jet effects on cylindrical afterbodies housing sonic and supersonic nozzles which exhaust against a supersonic stream at angles of attack from 90 to 180 the tests were conducted at a free stream mach number of 2 91 and at free stream reynolds numbers based on body diameter of 0 15x106 and stream static pressure investigated was from jet off to about 400 the data presented herein showed that in general variation of the ratio of jet total pressure to free stream static pressure jet exit mach number and ratio of jet exit diameter to body diameter had large influences on the body pressures on the windward halves of the after bodies and negligible influences on the leeward pressures there was a negligible effect of reynolds number on the body pressures the ratio of jet total pressure to free stream static pressure also had a large influence on the base pressures at all angles of attack schlieren studies showed details of the shock wave structure caused by the jet and the extent of the jet interference flow fields
CRAN	investigation of a retrocket exhausting from the nose of a blunt body into a supersonic free stream investigation of a retrocket exhausting from the nose of a blunt body into a supersonic free stream the pressure distribution and pressure drag of a blunt body with a supersonic jet issuing upstream from its center were determined at free stream mach numbers of 1 60 2 00 and 2 85 the thrust of the jet issuing from the model nose was varied to study its effects on flow around the model and to determine variation of pressure distribution and pressure drag of the model with the thrust at all mach numbers investigated the pressure drag decreased with increasing retrorocket thrust until a minimum value was reached further increases in retrorocket thrust resulted in increases in the pressure drag the resultant drag pressure drag plus retrorocket thrust but excluding base and skin friction drag of the model was reduced by retrorocket operation below the drag for a jet off condition except at very low retrorocket thrust coefficients the flow about the nose of the blunt body was very unstable throughout the range of mach numbers and retrorocket thrust coefficients investigated
CRAN	investigation of a retrocket exhausting from the nose of a blunt body into a supersonic free stream investigation of a retrocket exhausting from the nose of a blunt body into a supersonic free stream the pressure distribution and pressure drag of a blunt body with a supersonic jet issuing upstream from its center were determined at free stream mach numbers of 1 60 2 00 and 2 85 the thrust of the jet issuing from the model nose was varied to study its effects on flow around the model and to determine variation of pressure distribution and pressure drag of the model with the thrust at all mach numbers investigated the pressure drag decreased with increasing retrorocket thrust until a minimum value was reached further increases in retrorocket thrust resulted in increases in the pressure drag the resultant drag pressure drag plus retrorocket thrust but excluding base and skin friction drag of the model was reduced by retrorocket operation below the drag for a jet off condition except at very low retrorocket thrust coefficients the flow about the nose of the blunt body was very unstable throughout the range of mach numbers and retrorocket thrust coefficients investigated
CRAN	extension of boundary layer separation criteria to a m 6 5 utilizing flat plates with forward facing steps extension of boundary layer separation criteria to a m 6 5 utilizing flat plates with forward facing steps an experimental investigation has been made of the separation phenomena on a flat plate to which forward facing steps were attached to force separation both laminar and turbulent flows were investigated over a mach number range of approximately distributions shadowgraph and chemical film techniques the pressure rise at separation the laminar plateau pressure and the turbulent peak pressure were determined boundary layer surveys were made on a smooth flat plate and on a flat plate with roughness to force transition examinations of the separated flow showed that the predominant variable in the determination of the pressure distribution was the location of transition relative to the separation point and reattachment pure laminar transitional and turbulent types of separation were found in this mach number range the peak static pressure rise ratios for identical forward facing steps at a mach number of 6 25 were approximately 1 5 and 5 0 respectively for pure laminar and turbulent separation the effect of reynolds number on the peak pressure rise for turbulent separation for the lower mach number range was found to be very minor provided the step height was of the order of the boundary layer thickness as the mach number is increased the peak pressure coefficient for turbulent separation decreased from approximately 0 18 at a mach number of 4 to about 0 13 at a mach number of 6 25 the pressure coefficient at the separation point for laminar separation decreases from approximately 0 014 at a mach number of value at a mach number of 6 5 the results obtained with forward facing steps agree with the trends predicted based upon lower mach number studies
CRAN	experimental and theoretical studies of axisymmetric free jets experimental and theoretical studies of axisymmetric free jets some experimental and theoretical studies have been made of axisymmetric free jets exhausting from sonic and supersonic nozzles into still air and into supersonic streams with a view toward problems associated with propulsive jets and the investigation of these problems for jets exhausting into still air consideration is given to the effects of jet mach number nozzle divergence angle and jet static pressure ratio upon jet structure jet wavelength and the shape and curvature of the jet boundary studies of the effects of the ratio of specific heats of the jets are included as are observations pertaining to jet noise and jet simulation for jets exhausting into supersonic streams an attempt has been made to present primarily theoretical curves of the type that may be useful in evaluating certain jet interference effects and in formulating experimental studies the primary variables considered are jet mach number free stream mach number jet static pressure ratio ratio of specific heats of the jet nozzle exit angle and boattail angle the simulation problem and the case of a hypothetical hypersonic vehicle are examined
CRAN	equations tables and charts for compressible flow equations tables and charts for compressible flow this report which is a revision and extension of naca tn useful in the analysis of high speed flow of a compressible fluid the equations provide relations for continuous one dimensional flow normal and oblique shock waves and prandtl meyer expansions for both perfect and imperfect gases the tables present useful dimensionless ratios for continuous one  dimensional flow and for normal shock waves as functions of mach number for air considered as a perfect gas one series of charts presents the characteristics of the flow of air considered a perfect gas for oblique shock waves and for cones in a supersonic air stream a second series shows the effects of caloric imperfections on continuous one dimensional flow and on the flow through normal and oblique shock waves
CRAN	static aerodynamic characteristics of short blunt cones with various nose and base cone angles at mach numbers of 0 6 to 5 5 and angles of attack to 180 static aerodynamic characteristics of short blunt cones with various nose and base cone angles at mach numbers of 0 6 to 5 5 and angles of attack to 180 wind tunnel tests have been performed at mach numbers from 0 6 to 5 5 to determine coefficients of normal force axial force and pitching moment for short blunt cones as affected by changes in nose and base cone angles models with nose half angles of 10 and 20 were investigated the 10 nose half angle models were tested with a flat base and with base cones of 50 and 70 half angle the 20 nose half angle model had a 50 half angle base cone reynolds numbers for the test ranged from about maximum diameter variations in the base cone angle resulted in significant changes in the aerodynamic characteristics with lesser effects resulting from changes in nose cone angle in particular the model with the 50 half angle conical base had only one trim angle flat base and 70 half angle conical base had two trim angles a 0 and a 180 estimated variations of the aerodynamic characteristics with angle of attack by means of a modified newtonian theory were in good agreement with the experimental results the theory however failed to predict the trim point at a 180 for the flat based model
CRAN	free flight measurements of the static and dynamic stability and drag of a 10 blunted cone at mach numbers 3 5 and 8 5 free flight measurements of the static and dynamic stability and drag of a 10 blunted cone at mach numbers 3 5 and 8 5 tests were made of a short blunt nosed without a 50 half angle conical afterbody in a pressurized ballistic range at nominal mach numbers of 3 5 and of 90 000 and 220 000 respectively it was found that the models were statically stable about the center  of gravity location tested but exhibited neutral dynamic stability for flight at constant altitude the static stability was not affected by the but was nonlinear with angle of attack and varied with mach number the nonlinear variation of the pitching moment with angle of attack was accurately approximated by a cubic polynomial the static stability was only qualitatively predicted by modified newtonian theory the drag characteristics were in good agreement with values calculated by use of modified newtonian theory calculations of the oscillatory behavior of the configurations flying an example entry trajectory through the martian atmosphere indicated the configurations to be dynamically satisfactory pitching motions should converge to a small fraction of the amplitude at entry provided the initial angle of attack and pitch rate are not large enough to cause tumbling
CRAN	wind tunnel investigation of the static and dynamic stability characteristics of a 10degree semivertex angle blunted cone wind tunnel investigation of the static and dynamic stability characteristics of a 10degree semivertex angle blunted cone the static and dynamic stability characteristics of a blunted 10degree semivertex angle cone were studied the cone which had a modified spherical segment nose was tested with a flat base and with a truncated conical base all tests were performed in air at mach numbers from 0 65 to 2 20 with the angle of attack range from  4degree to 18degree presented are measurements of the normal force axial force base pressure and pitching moment from the static tests and the damping in pitch moment from the dynamic tests both models had satisfactory stability characteristics throughout the test mach number range but the addition of the conical afterbody had a large destabilizing effect
CRAN	preliminary investigations of spiked bodies at hypersonic speeds preliminary investigations of spiked bodies at hypersonic speeds generally accepted solutions for the problems of hypersonic flight appear at the moment to be centered around the use of blunt bodies to minimize the heat transfer rates there are however several other solutions to the problem and as part of an exploratory study of these solutions a detailed examination has been made of the flow over blunt bodies equipped with a spike these tests carried out at a mach number of about 14 in the princeton helium hypersonic tunnel have investigated the effect of varying spike lengths for flat faced and hemispherically nosed axially symmetric bodies detailed pressure distributions have been obtained as well as heat transfer rates these exploratory studies have shown that the use of a spike protruding from a hemispherical nosed cylinder at m 14 decreased the pressure level by an order of magnitude and the heat transfer to a fraction of that measured on a hemisphere without a spike the general technique appears to hold considerable promise for hypersonic flight
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic the real gas hypersonic flow parameters for helium have been calculated for stagnation temperatures from 0 f to 600 f and stagnation pressures up to 6 000 pounds per square inch absolute the results of these calculations are presented in the form of simple correction factors which must be applied to the tabulated ideal gas parameters it has been shown that the deviations from the ideal gas law which exist at high pressures may cause a corresponding significant error in the hypersonic flow parameters when calculated as an ideal gas for example the ratio of the free stream static to stagnation pressure as calculated from the thermodynamic properties of helium for a stagnation temperature of 80 f and pressure of 4 000 pounds per square inch absolute was found to be approximately 13 percent greater than that determined from the ideal gas tabulation with a specific heat ratio of
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic the effects of contamination of helium by air upon static pressure total pressure heat transfer and temperature measurements have been investigated in the 2 inch helium tunnel at the langley research center within the scope of the tests even a small amount of air is shown to affect these measurements the heat transfer and temperature measurements were made on a 26 6 half angle cone and demonstrated the effects of contamination qualitatively the wall static and center line pitot pressures show that if the contaminating air is held to less than about 0 2 percent by volume the error in indicated mach number is less than 1 percent as calculated from the rayleigh pitot equation the corresponding errors in wall static and center line pitot pressures are about 1 7 and 0 4 percent respectively
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic equations based on newtonian impact theory have been derived and a computational procedure developed with the aid of several design type charts which enable the determination of the aerodynamic forces and moments acting on arbitrary bodies of revolution undergoing either separate or combined angle of attack and pitching motions bodies with axially increasing and decreasing cross sectional area distributions are considered nose shapes may be sharp blunt or flat faced the analysis considers variations in angle of attack from  90 to 90 and allows for both positive and negative pitching rates of arbitrary magnitude the results are also directly applicable to bodies in either separate or combined sideslip and yawing maneuvers
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic the inviscid flow of a perfect gas over blunt nosed axisymmetric and two dimensional bodies at zero angle of attack has been calculated numerically on an ibm 7090 computer the computation consisted of the fuller blunt body solution for the subsonic and transonic regions and the method of characteristics for the supersonic region the flow fields about a number of blunt bodies were studied and the calculated results showed good agreement with experimental shock wave shapes surface pressure distributions and flow field surveys
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic this report presents equations tables and figures for use in the analysis of helium flow at supersonic and hypersonic speeds the contents of the report and presentation of the data parallel that of a similar reference work naca rep 1135 prepared for air flow the perfect gas relations for continuous one dimensional flow normal  and oblique shock waves and prandtl meyer expansions are the same as for air but are presented here for completeness the tables present the values of useful dimensionless ratios for continuous one dimensional flow and for normal shock waves as functions of mach number the helium viscosity relation as a function of temperature mass flow rates as a function of mach number and temperature and the reynolds number as a function of mach number and stagnation temperature are plotted the oblique shock characteristics of wedges and cones in helium at mach numbers of 12 16 20 and 24 are presented in a series of plots throughout all the computations helium is considered to be a perfect gas
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic representative experimental results are presented to show the current status of the panel flutter problem results are presented for unstiffened rectangular panels and for rectangular panels stiffened by corrugated backing flutter boundaries are established for all types of panels when considered on the basis of equivalent isotropic plates the effects of mach number differential pressure and aerodynamic heating on panel flutter are discussed a flutter analysis of orthotropic panels is presented in the appendix
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic charts of thermodynamic properties for equilibrium air are presented with sufficient accuracy to permit the calculation of flow parameters in hypersonic nozzles operating at stagnation temperatures up to 4 950 r and pressures up to 1 000 atm flow parameters calculated from these charts are presented for a series of stagnation temperatures between use of these parameters it is possible to calibrate a nozzle in the conventional way a method is also presented from which the flow parameters for conditions other than those chosen herein may be calculated real gas effects on the calculation of a hypersonic nozzle contour are shown by an example calculation in which the nozzle contour for mach number 12 was determined by including real gas effects and this contour was compared with one calculated by ideal gas considerations also presented are the approximate limiting mach numbers at which equilibrium air will just condense for various combinations of stagnation temperatures and pressures
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic air flow properties in nozzles were calculated and charted for equilibrium flow and two types of frozen flows in one type of frozen flow air was assumed to be in equilibrium from the nozzle reservoir to arbitrary points where chemical reactions and molecular vibrations became frozen in the other type it was assumed that molecular vibrations were in equilibrium throughout the nozzle and that chemical reactions became frozen at arbitrary points the calculations were made for a range of stagnation pressures up to 10 000 poinds per square inch absolute and stagnation enthalpies up to 24 500 btu per pound the flow properties charted were temperature pressure density velocity dynamic pressure mach number reynolds number molecular weight fraction and mass flow equilibrium flow properties through normal shock waves were also included
CRAN	free flight measurements of the static and dynamic free flight measurements of the static and dynamic charts have been prepared relating the thermodynamic properties of air in chemical equilibrium for temperatures to 15 000 k and for pressures from 10 to 10 atmospheres also included are charts showing the composition of air the isentropic exponent and the speed of sound these charts are based on thermodynamic data calculated by the national bureau of standards
CRAN	principles of creep buckling weight strength analysis of aircraft structures principles of creep buckling weight strength analysis of aircraft structures the possibility of a gradual instability failure of a column under compressive load has been recognized for some time marin presented an analysis of creep buckling based on a theory of creep bending but did not take into account the average stress due to axial loading the theory also neglected the transient nonlinear portion of the creep curve in efficient column design the average stress should be relatively high in comparison with the bending stresses that is the column should be as straight as possible and the slenderness ratio should not be too great under these conditions marins theory is not directly applicable although it gives good agreement with tests of columns having large slenderness ratios or large eccentricities
CRAN	principles of creep buckling weight strength analysis principles of creep buckling weight strength analysis published work on creep buckling has implied that failure of columns after a critical time is caused by initial imperfections such analyses are relatively complex and ultimately leave the choice of selecting the proper value of the initial imperfection to the designer furthermore recent test results on creep buckling of columns have indicated that there is a random and relatively unimportant effect of small initial imperfections on the critical time to avoid the difficulties associated with initial imperfections a formulation of the creep buckling phenomenon in terms of classical stability theory is presented the theory permits the extension of known solutions for plastic buckling of certain thin plates and shells to creep buckling problems
CRAN	principles of creep buckling weight strength analysis principles of creep buckling weight strength analysis a problem of creep stability of columns and plates is considered in an analysis use is made of two forms of the creep theory based on the strain hardening hypothesis for a uniformly compressed palte a comparison is made between the results according to the flow theory and strain theory
CRAN	principles of creep buckling weight strength analysis principles of creep buckling weight strength analysis the determination of column deflections and column buckling loads has been considered for many years the available theories however do not provide for materials which creep with time under constant loads for the design of structural members made of these materials a consideration of creep may be of practical importance plastics concrete and some metals creep at normal temperatures while other metals creep only at high temperatures and at stress values beyond the yield point a consideration of creep in the design of some structures appears appropriate in view of the modern developments in plastics and the presence of high stress values which are sometimes beyond the yield stress this paper gives a rational theory for predicting creep deflections in columns a special case using this theory is applied to the interpretation of some preliminary tests of an aluminum alloy
CRAN	principles of creep buckling weight strength analysis principles of creep buckling weight strength analysis the relation of the time dependent tangent modulus load  as conceived by shanley  to actual column capacity is clarified it may be interpreted as a limiting case of the conservative estimate the time dependent tangent modulus load is therefore an approximation to a conservative estimate the approximation however may be either conservative or nonconservative when applied to imperfect or real columns typical cases are discussed and experimental results for two alloys are cited
CRAN	note on creep buckling of columns note on creep buckling of columns it appears from libroves interesting analysis that for the case of creep buckling of columns the initial imperfections contained in ordinary columns provide the mechanism by which failure due to creep occurs after a period of time in fact it can be concluded from this analysis that a theoretically perfect column that is initially loaded below the time independent critical load will not buckle at all this is an interesting contrast to the case of static buckling where small initial imperfections play an insignificant role since the failing load of an initially imperfect column is substantially the same as that of a theoretically perfect column it is of interest therefore to conjecture whether there is any possible mechanism by which a column containing no initial imperfections can fail as a result of creep when the initial load is less than the theoretical buckling load
CRAN	note on creep buckling of columns note on creep buckling of columns the results of short time elevated temperature creep tests of objective of obtaining procedures for predicting column lifetime semiempirical lifetime curves are obtained with the aid of a previously published column creep theory and are used for deriving column curves the semiempirical lifetime curves are also used to study the effect of varying applied stress and out of straightness in the range considered small variations in out of straightness are found to be of little practical significance whereas small stress variations change the column lifetime considerably for the range of out of straightness encountered in the tests the data can be presented in plots that do not explicitly include out of straightness and plots of this type should be satisfactory for predicting column lifetime for design purposes
CRAN	note on creep buckling of columns note on creep buckling of columns a method for estimating allowable load capacities of columns subject to creep is presented the method which utilizes approximate stress distributions derived from isochronous stress strain curves to estimate column load capacities is shown to be conservative for the time for which the estimate is made an application of the method is made to test data on as received and on stabilized 24s t4 aluminum alloy a comparison of the computed column capacities with experimental capacities indicates that the method is satisfactory for estimating the decrease in capacity with increasing time easily obtained time dependent tangent modulus loads are discussed they are interpreted as being approximations to allowable load capacity estimates a limited application is made to test data and the results appear promising it is concluded that if certain limitations are recognized the method may prove to be useful because of its simplicity a presentation of the results of an experimental investigation of the effects of column imperfection and column material variation is made it is found that column capacity variations of the order of 10 per cent can result from column imperfection differences and column material variation the results of an experimental study of the variation of column capacity with temperature of exposure are presented they indicate that column efficiency as measured by decrease in capacity can be acceptable for very short times at the higher temperatures the efficiency at these higher temperatures falls rapidly however with increasing time
CRAN	note on creep buckling of columns note on creep buckling of columns the results of short time creep buckling and creep bending tests of slenderness ratio 111 are presented the tests were performed at 600 f and strain measurements were taken with high temperature electric resistance strain gages a description of the development of the gages is given in an appendix the column tests show that the critical time decreases much more rapidly with increasing load than with increasing initial deviation from straightness the bending tests indicate that the steady creep rate of the curvature is a simple power function of applied moment these latter results together with a previously derived creep buckling theory are used to develop a semiempirical formula suitable as a guide for the determination of the critical time for columns
CRAN	note on creep buckling of columns note on creep buckling of columns this paper describes theory and tests of the creep collapse of long thin aluminum alloy cylinders under external radial pressure steady state creep is assumed in the theoretical derivation the test temperatures were between 300 and 500 f the collapse time for each cylinder was calculated theoretically agreement between theoretical and test results was fair
CRAN	note on creep buckling of columns note on creep buckling of columns forty three cylinders of 40 inch length and 16 inch diameter made of 5052 0 aluminum alloy sheets of thickness were subjected to bending moments constant along the cylinder and in time in an oven which maintained a constant temperature of 500 f during the test all the cylinders failed by buckling the time that elapsed between load application and collapse was measured
CRAN	note on creep buckling of columns note on creep buckling of columns a theory of creep buckling is presented in which the instantaneous elastic and plastic deformations following the application of a load as well as the steady creep deformations are considered in an approximate manner equations are given from which the critical time that is the time elapsing between load application and the collapse of the column can be computed
CRAN	note on creep buckling of columns note on creep buckling of columns the general dynamic equation of creep bending of a beam loaded laterally and axially was derived for a linearly viscoelastic material whose mechanical properties can be characterized by four parameters the material can exhibit instantaneous and retarded elasticity as well as pure flow the equation derived was used to obtain the creep bending deflection of a beam in pure bending and of a column with initial sinusoidal deviation from straightness as expected the ratio of the creep deflections of the beam in pure bending and the deflections of a corresponding purely elastic structure is identical to the ratio of the creep strain and the corresponding elastic strain of a bar under simple tension or compression the results of the analysis of the creep deflection of the column showed that the deflections increase continuously with time and become infinitely large only when the loading time is correspondingly large however large deflections are obtained in reasonably short periods of time if the applied load is near to the euler load of the column the deflection time curves obtained from a numerical example are of the same type as those determined by experiment with aluminum columns
CRAN	note on creep buckling of columns note on creep buckling of columns the creep of a slightly crooked section column carrying a constant load is studied theoretically the material of the column is characterized by a strain time relationship under constant uniaxial stress of the form where is the total strain is the constant stress is the time and e a b and k are material constants this form was selected because it applies to at least two alloys  75s t6 aluminum alloy at 600 f and a low alloy steel at 800 and 1 100 f however the analysis is intended for any material having creep properties of the same form and for which the material constants are known a strain time relationship under variable uniaxial stress necessary for the column analysis is formulated from the constant stress properties with the aid of shanleys engineering hypotheses of creep the analysis leads to the conclusion that the lateral deflection approaches infinity  that is the column collapses  in finite time results are given showing the maximum length of time the column can support a given load before it collapses and the growth of stresses strains and deflections prior to collapse
CRAN	note on creep buckling of columns note on creep buckling of columns this paper is concerned with the solution of the creep buckling of columns instantaneous elastic and plastic deformations as well as the transient and secondary creep are considered formulae for the critical time at which a column fails are presented for integral values of the exponents appearing in the creep law
CRAN	note on creep buckling of columns note on creep buckling of columns a phenomenological relation between stress strain rate and temperature is suggested to account for the behavior of polycrystalline metals above the equicohesive temperature the properties of the metal included in the relation are elasticity linear thermal expansion and viscosity the relation may be integrated under various conditions to provide information on creep rates creep rupture stress strain curves and rapid heating curves it is shown that for one material   7075 t6 aluminum alloy sheet   the information yielded by the relation for these four applications agrees reasonably well with test data
CRAN	note on creep buckling of columns note on creep buckling of columns the phenomenological theory previously proposed in naca technical note 4000 for the behavior of metals at elevated temperatures has been modified to yield transient creep curves by assuming that the metal consists of two phases each with its own elasticity and viscosity the extended theory satisfies the basic requirements for a theory of transient creep at elevated temperatures that the transient creep be closely connected with the subsequent steady creep and that the apparent exponent of the time in the transient region be permitted wide variations between 0 and 1 from this theory it is possible to construct nondimensional creep curves which extend continuously from the transient region into the steady state region the corresponding family of creep curves for any metal may be obtained from the nondimensional family by use of appropriate constants the constants required are those obtained from steady creep measurements together with two additional constants which represent the difference between the phases the transient creep curves resulting from this theory are compared with the experimental curves for pure aluminum gamma iron lead and agreement is found
CRAN	note on creep buckling of columns note on creep buckling of columns a variational theorem is presented for a body undergoing creep solutions to problems of the creep behavior of plates columns beams and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem the application of the theorem is illustrated for plates and columns by the solution of two sample problems
CRAN	note on creep buckling of columns note on creep buckling of columns some general topics in elastic stability are discussed in particular attention is given to the relationship between adjacent equilibrium position and energy techniques to the effects of nonlinearity and to the sensitivity of certain stability problems to the character of the loading
CRAN	note on creep buckling of columns note on creep buckling of columns a general variational theory of elastic stability that was originated by e trefftz 1 is applied to the problem of buckling of rings of rectangular cross section subjected to uniform external pressure the theory is believed to be more rigorous than previous treatments of the problem since it avoids conventional assumptions of curved beam theory such as the assumptions that plane sections remain plane and that radial stresses vanish the classical result of levy 2 is confirmed for a ring of infinitesimal thickness new results are obtained which show the effect of the finite thickness of a ring on the coefficients in the buckling formula
CRAN	on the conservativeness of various distributed force systems on the conservativeness of various distributed force systems the necessity of determining the conservativeness of force systems in instability problems is discussed in reference 1 it is shown that whereas kinetic methods are generally applicable for the determination of instability loads the statical methods usually employed are valid only for conservative and nongyroscopic systems small changes in the character of the loading could make an otherwise conservative system nonconservative and cause a large change in the magnitude of the buckling load the buckling load of the cantilever column example in reference 1 is for tangential end loading eight times that for conservative constant directional loading
CRAN	the design of tubes under uniform external pressure on the basis of assumed inaccuracies the design of tubes under uniform external pressure on the basis of assumed inaccuracies since the failure of tubes under uniform external pressure depends very much upon the various kinds of imperfections in them it seems logical to derive a design formula for such tubes in which the quantities depending on imperfections will appear explicitly the most common imperfection in tubes is an initial ellipticity the limiting value of which in each type of tube is usually well known from numerous inspection measurements the deviation of the shape of the tube from a perfect circular form can be defined by the initial radial deflections w
CRAN	note on creep buckling of columns note on creep buckling of columns a long thin walled cylindrical shell is loaded by a uniform external pressure equations are developed for the time behavior of the shape of the cross section under the following conditions formations expressible by a power creep law b the initial and subsequent mode shape of the deviations from circularity of any cross section is two lobed and c the shell construction is of the sandwich type with concentric cylindrical membranes taking normal stresses and an annular core supporting shear without deformation explicit solutions are obtained for the particular case of the cubic creep law it is shown that the nondimensional amplitude of the cross sectional mode shape briefly shape factor will become infinite in a finite time curves of shape factor versus time and of collapse time versus initial value of the shape factor are presented also given are an explicit expression for and a curve of the expected variation in collapse time owing to uncontrollable deviations from a nominal initial value of the shape factor it is shown that the expected variation is small if the nominal initial shape factor value is sufficiently large
CRAN	note on creep buckling of columns note on creep buckling of columns the stability of a compressed elastic ring has been studied by a method which can be extended to solve the problem of the stability of a flexible heavy structure spread by a system of hoops as in a crinoline skirt the original work by levy which was developed by timoshenko and love cannot be generalized to problems in which the compressing forces are affected by the deformation of the ring it is shown that the load at which a ring will buckle depends not only upon the magnitude of the load but also upon its first derivative relative to the radial distance a positive derivative causes the ring to buckle at a higher load when this result is applied to a cone of heavy and loosely draped fabric spread by a rigid hoop of radius and a larger and flexible hoop of radius below it both hoops being in horizontal planes then various modes of buckling other than oval are possible according to the relative magnitudes of and it is found that oval buckling changes to three wave buckling when three wave changes to four wave when and as and approach nearer to equality the buckled form progressively changes to more waves when applied to a structure spread by many horizontal hoops of which the top one is rigid and oval it is found that all other hoops if each is designed to the criterion will have the same absolute deviation from circularity as the rigid hoop if any one hoop is designed so that then the oval shape of the rigid hoop is magnified on all flexible hoops
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells according to marguerre proc 5th internat congress appl mech cambridge mass 1938 wiley new york shells are governed by three simultaneous differential equations in the three displacements the author has considerably simplified this theory for the case of transverse vibrations by ignoring the longitudinal inertia terms thus reducing the problem to that of solving two simultaneous differential equations in a stress function and one displacement component this simplification is justified by an order of magnitude analysis and illustrated by considering the vibrations of a paraboloidal shell with a rectangular boundary
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells it is shown that a perfectly straight bar subjected to a state of uniform shear stress will buckle in a manner similar to a column under compression if the shear stress exceeds a certain critical value the buckling equations are obtained by the newtonian approach and also by the application of the principle of minimum potential energy in order to provide additional insight into this buckling mechanism a simple model is introduced and analyzed
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells the deformation and complete stress distribution are determined for each of the following edge loaded thin shells 1 a right circular cylinder 2 a frustum of a right circular cone and 3 a portion of a sphere the locations of maximum circumferential and meridional stresses are also found equations are developed for discontinuity shear and moment at the following junctions circular cylinder 2 axial change of thickness in a cone 3 change of thickness in a portion of a sphere cylinder and a portion of a sphere
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells an experimental investigation was made 1 to evaluate previously published theoretical procedures for the prediction of stress distribution for cases of radially symmetric abrupt change in wall thickness of thin walled cylinders subject to internal pressure and 2 to investigate the significance of stresses attributable to the presence of thickness changes typical of design practice one theory was adequate in itself for solution of the case of continuous middle surface use of the second theoretical procedure was required to determine the additional stresses arising from discontinuous middle surfaces at the change in thickness comparisons were made between theoretical and experimental stress distributions for cases with continuous middle and continuous inner surfaces for radially symmetric changes in wall thickness of a cylinder subject to internal pressure for diameter to larger wall thickness ratios of 117 and 28 and for the case of a continuous outer surface for a ratio of 28 in all tests the ratio of wall thicknesses at the change in wall thickness was 0 4 there was reasonably good correlation between theoretical and experimental curves of stress distribution on the basis of this correlation it was concluded that the applicable theories were valid it was shown that inclusion of the stresses arising from the condition of discontinuous middle surfaces at a change in thickness has an important effect on stress distribution in the case of a cylinder with a continuous outer surface the maximum mean effective stress was of sufficient magnitude to indicate that this geometry should be avoided in design if possible the maximum mean effective stress was not increased to a significant degree by the presence of a change in wall thickness in the other cases
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells experimental measurements of pressures and heat transfer rates over three blunt afterbodies of small fineness ratio in fully separated wakes are presented the afterbodies are generally similar in shape but have different stepdown heights from the end of the forebody tests were made by means of a new shroud technique over a range of reynolds numbers closely corresponding to typical flight conditions at mach numbers on the order of 20 considering models on the order of 5 ft in diameter at about 120 000 ft altitude stagnation temperatures on the order of 1 300 r to strictly speaking the test flows correspond to prototype flows which would be created by a forebody consisting of a sharp or slightly blunted 54 half angle cone which turns cylindrical for a short distance and then connects with the afterbody judiciously interpreted the results may be considered to have a somewhat wider applicability for approximation purposes the results are presented and compared with each other in terms of nondimensional variables based on flow conditions at the end of the forebody the pressure distribution along an afterbody is seen to be roughly uniform in each run for a given point on an afterbody the ratio of pressure to the stagnation pressure at the forebody end or exit decreases with increasing stagnation pressure or reynolds number the present pressures and pressure reynolds number variations fig 8 are compared with values obtained from chapmans mach 2 or 3 base pressure data qualitative and some quantitative agreement is noted in the reynolds number range comparable to those of the present tests chapmans exit boundary layers were considered to be laminar an approximate check of the heat transfer rate at the forebody end in the present tests also indicates a laminar rate no information was obtained concerning the possible transition of the free mixing separated boundary layer covering the wake an adverse pressure gradient on the cylindrical end of the forebody figs 7 a and 7 c was observed heat transfer rates are seen to be roughly uniform over an afterbody in each run although some increase in the streamwise direction is noted the afterbody nusselt number n varies with the reynolds number r evaluated at the forebody end roughly in the manner n r where generally fig 13 heat rates on the rear faces of the afterbodies are almost twice the values on the sides the heat rates on the large step body are higher than those on the body of zero stepdown height in an addendum it is shown that the prandtl meyer expansion angle of the flow leaving the afterbody increases with increasing test reynolds number and that the corresponding local mach number square increases linearly with reynolds number the effect is to keep the local wake reynolds numbers virtually constant with increasing test reynolds number while the afterbody heat rates increase sharply the expansion angle on the afterbody of zero stepdown height is significantly smaller than on the stepped down bodies this may affect the decreased heat rates on this body
CRAN	analysis of stresses in the elements of shell structure analysis of stresses in the elements of shell structure the love meissner analysis for thin shells has previously been applied to cones of uniform wall thickness and solutions for the stress resultants were given in terms of kelvins functions since tabulation of these functions for large arguments is not practical considerable computation was still required in the present paper the authors define special functions which eliminate the necessity of evaluating kelvin s functions and which may be used with simple algebraic and trigonometric functions to compute the boundary forces and displacements for cones for various loading conditions these special functions also make clear the magnitude of errors which result from geckeler s and other approximate solutions
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells the report presents information on the stress problems in the analysis of pressurized cabins of high altitude aircraft not met with in other fields of stress analysis relating to aircraft the material may be roughly divided into shell problems and plate problems the former being concerned with the curved walls of the cabin or pressure vessel and the latter being concerned with small rectangular panels of its walls framed by stiffeners but not necessarily plane
CRAN	on transverse vibrations of thin shallow elastic shells on transverse vibrations of thin shallow elastic shells a numerical analysis is given for the solution of the general equations of thin shells of revolution subjected to rotationally symmetric pressure and temperature distributions the basic differential equations are in a very general form which permits the geometry of the shells considered to be specified by discrete data points the analysis determines elastic stresses strains and displacements for multi layer and multi sectional shells of revolution surface loads temperatures thicknesses and material properties may vary arbitrarily in the meridional direction temperatures and material properties can also vary through the thickness the solution is obtained by direct computation using a numerical method that employs two by two coefficient matrices and hence avoids the problems of slow convergence the solution has been programmed in a semi algebraic language which can be used on most high speed computers comparisons of numerical solutions to known exact and approximate solutions of the thin shell equations are made to demonstrate the accuracy of this method
CRAN	on the theory of thin elastic shells on the theory of thin elastic shells general equations for the symmetrical finite deflection of a rotationally symmetric thin shell are first obtained for small deflections these equations are reduced to a pair of equations for the change of slope of the shell surface and the product of the undeformed radius of the shell to the radial stress this choice of dependent variable is shown to be advantageous two cases of shallow shells give particularly simple solutions parabolic shells of nth degree and uniform thickness and parabolic shells of mth degree with thickness varying as mth power of the distance from the apex for the first case the solutions can be expressed in terms of cylinder functions for the second in powers of the paper concludes with a discussion of the asymptotic solutions for small thickness
CRAN	the bending strength of pressurized cylinders the bending strength of pressurized cylinders discussion of previously presented experimental data for the loading of pressurized cylinders in terms of membrane theory
CRAN	the bending strength of pressurized cylinders the bending strength of pressurized cylinders a theoretical solution is given for the critical stress of thin walled cylinders loaded in torsion the results are presented in terms of a few simple formulas and curves which are applicable to a wide range of cylinder dimensions from very short cylinders of large radius to long cylinders of small radius theoretical results are found to be in somewhat better agreement with experimental results than previous theoretical work for the same range of cylinder dimensions
CRAN	the bending strength of pressurized cylinders the bending strength of pressurized cylinders be described here is attributed to the russian investigator v g galerkin whose original papers are inaccessible to the present writer his knowledge of the method is derived from a description given in a paper by e p grossman grossman states that the method was given by galerkin in his treatise p 897 and that applications to oscillation problems were first made by v p lyskov it is pointed out by grossman that galerkins process in applications to mechanics leads to the same results as lagranges principle of virtual work but employs a special co ordinate system the method of galerkin belongs to the same general class as those of rayleigh and ritz for it seeks to obtain an approximate solution of a differential equation with given boundary conditions by taking a function which satisfies these conditions exactly and proceeds to specialise the function in such a manner as to secure approximate satisfaction of the differential equation the selected function is a linear combination of n independent functions and the coefficients are determined by a process of integration the galerkin process can be considered from two points of view a simply as a means for the approximate solution of differential equations and treatment of problems concerning the statics and dynamics of elastic and other deformable bodies these two aspects are treated separately in parts 1 and 2 of the paper respectively and will now be briefly discussed which satisfies the boundary conditions in the differential equation be since the result should be zero is the error in the differential equation then the galerkin process consists in choosing the n coefficients in the function in such a manner that n distinct weighted means of the error taken throughout a certain range of representation shall all be zero as a generalised force and the multipliers used to weight the errors are the virtual displacements corresponding to increments of each of the generalised co ordinates in turn thus the vanishing of the weighted mean is here interpreted as the vanishing of the virtual work in the appropriate displacement the degree of accuracy attaindd can be increased indefinitely by increasing the number of independent functions employed but this entails a great increase of labour however when the functions are well chosen an excellent approximation can be obtained by the use of a very small number as is sufficiently shown by the examples included in this paper
CRAN	a small deflection theory for curved sandwich plates a small deflection theory for curved sandwich plates a small deflection theory that takes into account deformations due to transverse shear is presented for the elastic behavior analysis of orthotropic plates of constant cylindrical curvature with considerations of buckling included the theory is applicable primarily to sandwich construction
CRAN	elastic constants for corrugated core sandwich plates elastic constants for corrugated core sandwich plates the sandwich plate consisting of corrugated sheet fastened between two face sheets is considered application of existing theories to the analysis of such a sandwich plate requires the knowledge of certain elastic constants formulas and charts are presented for the evaluation of these constants the formulas for three of these constants were checked experimentally and found to give values in close agreement with the experimental values
CRAN	compressive buckling of simply supported curved plates and cylinders of sandwich construction compressive buckling of simply supported curved plates and cylinders of sandwich construction theoretical solutions are presented for the buckling in uniform axial compression of two types of simply supported curved sandwich plates the corrugated core type and the isotropic core type the solutions are obtained from a theory for orthotropic curved plates in which deflections due to shear are taken into account results are given in the form of equations and curves
CRAN	the stability of thin walled unstiffened circular cylinders under axial compression including the effects of internal pressure the stability of thin walled unstiffened circular cylinders under axial compression including the effects of internal pressure in the design of high speed aircraft the importance of unpressurized and pressurized monocoque cylinders necessitates a reliable analysis procedure for the compressive buckling of cylindrical shells analysis by the classical small deflection theory has proved inadequate recent large deflection theoretical treatments of the problem have shown reasonable correlation with experiments but require a prior knowledge of the initial imperfections of the cylinder developed in this paper is a semiempirical procedure which permits a compressive buckling analysis of cylindrical shells with a knowledge of the cylinder geometry only this analysis is achieved by correlating experimental data statistically with theoretical parameters in order to provide data not previously available an extensive series of axial compression tests of pressurized cylinders has been performed these data together with all other known test data are analyzed semiempirically in the analysis best fit curves are presented using theoretical parameters and shapes of curves where applicable unpressurized and pressurized cylinder compressive buckling curves are then developed as 90 per cent probability curves from the test data in general these statistically defined design curves are significantly lower than previously available design curves
CRAN	recent advances in the buckling of thin shells recent advances in the buckling of thin shells the importance of the field of shell analysis is evidenced by the fact that in august 1959 the international union of theoretical and applied mechanics conducted a symposium on the theory of thin elastic shells in delft holland this special meeting was attened by approximately 65 scientists in this field from 14 countries this symposium indicated that considerable interest currently exists in such relatively new topics as the buckling of bimetallic shells pressurized shells creep buckling and dynamic buckling as well as in the more traditional problems involving isotropic shells of various geometries
CRAN	spherical cap snapping spherical cap snapping a nonlinear boundary value problem for the determination of the rotationally symmetric deformations of a clamped spherical cap under external pressure is solved by finite differences the numerical solutions are obtained by employing a previously developed iteration procedure a special case of the difference equations is solved explicitly and yields a justification of the iteration method as well as insight into the properties of the more accurate numerical solutions buckled and unbuckled equilibrium states are obtained and the shape of the pressure deflection curve which is usually assumed for these states is verified for a large class of caps close estimates are given for the upper and lower buckling loads and an intermediate buckling load  i e the dead weight load the stresses and deflections in the buckled and unbuckled states are examined and compared with an asymptotic solution valid in the interior of very thin shells boundary layers are found to develop in the buckled states both as the loading increases and as the thickness of the shell decreases
CRAN	iterative solutions for the non linear bending of circular plates iterative solutions for the non linear bending of circular plates the authors study non linear von karman equations for bending of a thin circular plate under uniform normal pressure discussion is mainly concerned with plates clamped at the edges and with zero radial displacement but analysis is valid for other edge conditions solution is by an iterative procedure whose convergence properties are studied by means of integral equations method is then applied to finite difference formulation of the differential equations in order to obtain numerical solutions numerical results are compared with previous work by other authors and the advantages of the present method are indicated
CRAN	non linear bending and buckling of circular plates non linear bending and buckling of circular plates iterative solutions of finite difference approximations of the non linear von karman plate equations are presented results are obtained for circular plates under a variety of boundary conditions subjected to either uniform lateral pressure or uniform edge thrust the solution carried out numerically on the aec univac at new york university yields a complete description of stresses and deflections for an apparently unlimited range of load parameters in addition boundary layer phenomena are discussed for computing purposes this iterative method proves to be superior to the previously used power series method and may be applicable to other non linear problems
CRAN	axisymmetric large deflections of circular plates subjected to thermal and mechanical load axisymmetric large deflections of circular plates subjected to thermal and mechanical load this paper is concerned with the nonlinear axisymmetric analysis of circular plates with in plane edge restraint both temperature and mechanical loads are accommodated as an extension of investigations performed for the isothermal mechanical loading problem an exact mathematical formulation within the framework of the v karman large strain displacement relations is developed the equilibrium equations and boundary conditions are then derived by utilizing the calculus of variations for arbitrary axisymmetrical temperatures and normal distributed loading the satisfaction of equilibrium and compatibility equations requires the solution of two simultaneous nonlinear ordinary differential equations subject to the prescribed boundary conditions analytical solutions of such equations are apparently not possible and therefore numerical procedures must be employed a finite difference procedure utilizing relaxed iterations developed by h keller and e reiss and employed by them for the solution of isothermal problems with apparently unlimited load parameter ranges is used here for combined thermo mechanical problems numerical results are presented for the special case of a simply supported circular plate with radially immovable boundaries subject to a uniform pressure and an arbitrary temperature variation through the thickness tained for a large range of temperature and load parameters however because of space limitations only a limited amount of data are presented in this paper
CRAN	the uniform section disk spring the uniform section disk spring the authors point out in this paper that initially coned annular disk springs of uniform cross section may be proportioned to give a wide variety of load deflection curves not readily obtainable with the more conventional forms of springs and that although the versatility of this type spring has long been indicated the formulas available have not been presented in a manner to disclose readily the effect of spring proportions on characteristics therefore the authors have derived the formulas presented in this paper with the intention that the formulas will aid the designer in arriving at suitable characteristics by choice of spring geometry these new formulas have been in use for several years at the general motors corporation research laboratories section and their reliability has been checked by tests of springs used in a variety of special test equipment
CRAN	the conical disk spring the conical disk spring this paper presents approximate formulas to describe the behavior of the conical disk spring it is assumed that the shallow conical shell remains conical when subjected to the axially symmetric edge loads the principle of stationary potential energy is used to derive the relations between load and deflection formulas relating the applied loads stresses and deflections are given for several types of edge constraint the analysis is essentially a refinement and extension of the previous work of almen and laszlo
CRAN	the nonlinear conical spring the nonlinear conical spring the large symmetric deformations of shallow conical shells are of interest in the design of nonlinear conical disk springs in most applications a uniformly distributed axial load acts at the inner and outer edges these edges are otherwise free several approximations have been proposed to describe the behavior of these springs a first approximation 1 is based on the assumption that meridional strains are negligible this requires that the shell remain conical after deformation and also that the extensional strain of meridional lines on the middle surface vanish another approximation 2 retains only the assumption that the shell remains conical the first assumption satisfies neither of the two boundary conditions at the free edges the latter violates the condition of vanishing moment at the free edges recently the authors presented a series solution 3 for a special case namely the case of an annular plate under similar loading numerical solutions for the shallow conical shell under these conditions of load have also been obtained 4 an examination of these results indicates that the meridional bending stresses are of much smaller magnitude than the circumferential bending stresses hence the present analysis is based on the neglect of the meridional bending moment
CRAN	buckled states of circular plates buckled states of circular plates authors discuss the thin elastic circular disk of constant thickness subjected to a constant compressive thrust applied at its edge the analysis presented is based upon the nonlinear von karman equations of plate theory and is applied to disks with completely clamped and completely simply supported edges
CRAN	turbulent mixing of a rocket exhaust jet with a supersonic stream including chemical reactions turbulent mixing of a rocket exhaust jet with a supersonic stream including chemical reactions the equations for the turbulent mixing of a two dimensional supersonic jet issuing into an ambient supersonic stream are formulated both streams consist of a mixture of chemically active and possibly reacting gases therefore any heat release by chemical reaction is included the net mass rate of production of species is obtained on the assumption that the reaction rate constant is given by an expression reducible to the classical arrhenius law the equations first given in terms of the x and y coordinates are expressed in dimensionless form and in terms of the x and coordinates where is the stream function the resulting expressions are all of the heat conduction type they are put in a finite difference form by using the crank nicolson method of substituting finite difference approximations for both the time and space derivatives the mixture is assumed to consist of six species namely h2o h2 o2 co2 co and n2 and the oxidation of h2 and co is assumed to take place according to a single step chemical reaction the solution of the problem is based on the simultaneous solution of 8n linear algebraic equations in 8n unknowns n being the number of internal grid points at every step in the x direction and 8 the total number of unknowns at each grid point namely velocity temperature and concentration for each of the six species a method of obtaining initial and boundary conditions from available inviscid jet flow solutions is discussed the equations are programed for calculation on an ibm 704 computer finally one typical case is considered and plots of velocity temperature and concentration profiles are given for the initial stages of development of the mixing layer
CRAN	an experimental and theoretical investigation of second order wing body interference at high mach number an experimental and theoretical investigation of second order wing body interference at high mach number the second order wing body interference theory of landahl and beane is used in the theoretical calculation of the pressure distributions over the wing of a wing body combination results are compared with experimental values obtained from wind tunnel tests at a mach number of 7 35 on a cone cylinder non lifting body with a triangular wing of wedge section set at incidences of 0 3 6 and 10 it is shown that interference effects can be very large and can be calculated theoretically with good accuracy
CRAN	on obtaining solutions to the navier stokes equations with high speed digital computers on obtaining solutions to the navier stokes equations with high speed digital computers the purpose of this paper is to show how to obtain steady state solutions to the navier stokes equations on a high speed digital computer first the relative merits of various finite difference formulae are discussed thereafter the main part of the paper is concerned with the methods used to solve the finite difference equations and an investigation is made of all the simpler iterative methods
CRAN	propeller slipstream effects as determined from wing pressure distribution on a large scale six propeller vtol model at static thrust propeller slipstream effects as determined from wing pressure distribution on a large scale six propeller vtol model at static thrust during static thrust tests of a large scale general research model having a tilting wing and double slotted flaps static pressure measurements were made on a wing segment behind one propeller to survey the effects of the slipstream for the conditions of highest slipstream energy the hovering end point of aerodynamic parameters for aircraft having vertical and short take off and landing capability the tilt wing configuration zero flap deflection was a 6 spanwise variation in effective angle of attack in a span of slightly less than 1 propeller diameter effective changes in camber on the tilt wing configuration as a result of slipstream rotation the radial velocity gradient and the resultant spanwise flow were negative and had a maximum magnitude of less than 2 percent chord for the deflected slipstream configuration double slotted flaps deflected effects important to the hovering performance were found including a 40 percent spanwise variation in effective thrust recovery and a 20 spanwise variation in effective thrust turning
CRAN	a free flight investigation of ablation of a blunt body to a mach number of 13 1 a free flight investigation of ablation of a blunt body to a mach number of 13 1 a five stage rocket propelled research vehicle system was flown to a maximum mach number of 13 1 at an altitude of approximately 78 000 feet to determine ablation characteristics of teflon in free flight continuous in flight measurements were made using sensors developed by the national aeronautics and space administration the sensors were located on the blunted face of a nose cone constructed from teflon with one at the stagnation point and two others at a surface distance of 0 62 radius on opposite sides of the stagnation point the ablated length measurements were in close agreement with analytical predictions the analytical predictions upon inclusion of the pertinent material property values should be applicable to other materials as well as teflon
CRAN	wind tunnel measurements of aerodynamic damping derivatives of a launch vehicle vibrating in free free bending modes at mach numbers from 0 70 to 2 87 and comparisons with theory wind tunnel measurements of aerodynamic damping derivatives of a launch vehicle vibrating in free free bending modes at mach numbers from 0 70 to 2 87 and comparisons with theory the aerodynamic damping of a flexibly mounted aeroelastic model with a blunted conical nose and a cylindrical afterbody was measured at mach numbers from 0 70 to 1 20 at several levels of dynamic pressure and two weight conditions and at mach numbers from 1 76 to 2 87 at one weight condition the first two free free flexible modes of vibration were investigated also investigated at mach numbers from 0 9 to 1 2 was the aerodynamic damping in the first free free modes of a model which had a hammerhead nose the base diameter of the blunted cone was greater than the diameter of the afterbody which necessitated a reflex angle downstream from the cone base two basically different methods the electrical power input and the decaying oscillations methods were used to determine the damping and frequencies the experimentally determined values are compared with some applicable theories the results of the investigation indicate that the aerodynamic damping in the elastic modes of vibration was small for all configurations tested the maximum aerodynamic damping measured in the first mode was on the order of damping the aerodynamic damping was found to be even less for vibration modes higher than the first reduced frequency effects were found to be negligible for the range investigated agreement of calculated aerodynamic damping derivatives with the experimental results was not good generally the experimentally determined derivatives were larger than those predicted by the various theories used the bond packard theory appeared to give the best agreement for the first free free vibration mode but gave the worst agreement for the second mode measurements made on the configuration that had a hammerhead nose indicated small negative aerodynamic damping in the mach number range from 0 95 to 1 00 aerodynamic stiffness effects were found to be small and within the experimental scatter wind on frequency determination was accurate only to approximately 1 percent
CRAN	plastic stability theory of geometrically orthotropic plates and cylindrical shells plastic stability theory of geometrically orthotropic plates and cylindrical shells a linear eighth order equilibrium differential equation for plastic buckling of geometrically orthotropic thin cylindrical shells is derived this equation is used to obtain explicit solutions for long flat plates and wide columns under axial compression and moderate length cylinders under external pressure torsion and axial compression
CRAN	instability analysis of cylindrical shells under hydrostatic pressure instability analysis of cylindrical shells under hydrostatic pressure to determine the elastic buckling pressure of simply supported cylindrical shells subjected to lateral and axial hydrostatic forces various versions of linear bending theories have been employed in the past for certain shell dimensions however the expressions commonly used may yield substantially differing results in what follows recent work on this problem by a e armenakas and the writer is briefly reviewed this work consisted primarily in employing a general bending theory of circular cylindrical shells under the influence of initial stress developed earlier by the same authors to re examine the problem mentioned and compare the results with those of previous investigations the outcome was the establishment of a simple but accurate expression for the buckling pressure applicable to a wide range of shell dimensions
CRAN	design and testing of honeycomb sandwich cylinders under axial compression design and testing of honeycomb sandwich cylinders under axial compression experimental results for 36 diameter honeycomb cylinders fabricated with thin 0 010 aluminum faces and cores prove that it is quite feasible to stabilize thin faces so they can be loaded beyond the yield point the effect of initial imperfections and the various modes of failure are discussed
CRAN	buckling of orthotropic and stiffened conical shells buckling of orthotropic and stiffened conical shells donnell type stability equations for thin circular orthotropic conical shells are presented and solved for external pressure axial compression and combined loading the solution is likewise applied to stiffened conical shells correlation with equivalent cylindrical shells yields a simple approximate stability analysis for orthotropic or ring stiffened conical shells under hydrostatic pressure the general instability of stiffened conical shells under hydrostatic pressure is also analysed by a more accurate approach preliminary experimental results for buckling of ring stiffened conical shells under hydrostatic pressure are presented and discussed
CRAN	stability of thin torispherical shells under uniform internal pressure stability of thin torispherical shells under uniform internal pressure the stability of the toroidal portion of a torispherical shell under internal pressure is considered from the point of view of the linear buckling theory a detailed stress analysis of the prebuckled shell is made employing asymptotic integration the change in potential energy of the shell is then minimized using a rayleigh ritz procedure for actual computation of the critical pressure numerical results reveal that elastic buckling may occur for very thin shells whose material has a relatively high value of the ratio of yield stress to elastic modulus
CRAN	ignition and combustion in a laminar mixing zone ignition and combustion in a laminar mixing zone the analytic investigation of laminar combustion processes which are essentially two  or three dimensional present some mathematical difficulties there are however several examples of two dimensional flame propagation which involve transverse velocities that are small in comparison with that in the principal direction of flow such examples occur in the problem of flame quenching by a cool surface flame stabilization on a heated flat plate combustion in laminar mixing zones etc in these cases the problem may be simplified by employing what is known in fluid mechanics as the boundary layer approximation since it was applied first by prandtl in his treatment of the viscous flow over a flat plate physically it consists in recognizing that if the transverse velocity is small the variations of flow properties along the direction of main flow are small in comparison with those in a direction normal to the main flow the analytic description of the problem simplifies accordingly the present analysis considers the ignition and combustion in the laminar mixing zone between two parallel moving gas streams one stream consists of a cool combustible mixture the second is hot combustion products the two streams come into contact at a given point and a laminar mixing process follows in which the velocity distribution is modified by viscosity and the temperature and composition distributions by conduction diffusion and chemical reaction the decomposition of the combustible stream is assumed to follow first order reaction kinetics with temperature dependence according to the arrhenius law for a given initial velocity composition and temperature distribution the questions to be answered are 1 does the combustible material ignite and 2 how far downstream of the initial contact point does the flame appear and what is the detailed process of development since the hot stream is of infinite extent it is found that ignition always takes place at some point of the stream however when the temperature of the hot stream drops below a certain value the distance required for ignition increases so enormously that it essentially does not occur in a physical apparatus of finite dimension the complete development of the laminar flame front is computed using an approximation similar to the integral technique introduced by von karman into boundary layer theory
CRAN	a practical method for numerical evaluation of solutions of partial differential equations of the heat conduction type a practical method for numerical evaluation of solutions of partial differential equations of the heat conduction type three approximate methods for the solution of the nonlinear equation of heat flow in a medium where heat is being generated by a chemical reaction are compared the equations are where subscripts indicate partial differentiations and q k a are
CRAN	theoretical and experimental investigation of second order supersonic wing body interference theoretical and experimental investigation of second order supersonic wing body interference approximate second order solutions for the supersonic flow around wing body combinations are calculated using two different theoretical models small and the wing sweep small in comparison with that of the mach cone are considered the analysis is restricted to such high mach numbers that m 2 1 and an approximate formula common to the two models is then found for the second order interference term this formula can also be used to correct experimental pressure distributions for the effect of nonuniformities in the wind tunnel flow in order to test the theory wind tunnel experiments on non lifting cone cylinder bodies in combination with wings of simple shapes were performed pressure distributions were measured at m 3 and m 4 both around the bodies and on the wings separately as well as in combination and it was found that the second order interference was predicted reasonably well by the simplified theory
CRAN	an experimental and theoretical investigation of second order supersonic wing body interference for a non lifting body with wings at incidence an experimental and theoretical investigation of second order supersonic wing body interference for a non lifting body with wings at incidence pressure distributions on the wing of two wing body combinations are measured experimentally at mach numbers 3 and 4 with the wing at various incidences in the range 0degree to 10degree the results are compared with theoretical results which include interference effects calculated according to the second order supersonic wing body interference theory due to landahl and beane 1 this theory having been tested previously for non lifting wing body combinations is thus tested also for wings at incidence the agreement between theory and experiment is found to vary with mach number and wing sweepback for the higher mach number and moderate sweepback the theory gives a good prediction of pressure distribution but for the most adverse condition of low mach number and large sweepback the theory is found to overestimate the interference effects this is expected as the theory assumes the sweepback of the wings is small compared with that of the mach line an empirical guide to the limit of application of the interference theory is given within this limit the agreement between theory and experiment is found to deteriorate only a little with increase of incidence over the range tested
CRAN	an approximate method for determining the displacement effects and viscous drag of laminar boundary layers in two dimensional hypersonic flow an approximate method for determining the displacement effects and viscous drag of laminar boundary layers in two dimensional hypersonic flow a simplified approximate theory is presented by means of which the laminar boundary layer over an insulated two dimensional surface may be calculated a linear velocity profile being assumed and an estimate made of its effect in changing the pressure distribution over the profile upon which the boundary layer is formed skin friction is also determined comparisons of results from this theory are made with experimental results at a mach number of 6 86 and a reynolds number of
CRAN	a method of solution with tabulated results for the attached oblique shock wave system for surfaces at various angles of attack sweep and dihedral in an equilibrium real gas including the atmosphere a method of solution with tabulated results for the attached oblique shock wave system for surfaces at various angles of attack sweep and dihedral in an equilibrium real gas including the atmosphere a new method is derived for solving the attached oblique shock wave system for surfaces at various angles of attack sweep and dihedral in any real gas in equilibrium results are tabulated for the following ranges angle of attack 0degree to 65degree angle of sweep 0degree to 75degree angle of dihedral 0degree to 30degree mach number 3 to 30 and effective specific heat ratio parameter 1 10 to 1 67 both the method and tabulated solutions are easily adaptable to flight in any gas or in the atmosphere of any planet an illustrative example is presented based on the ardc 1956 model atmosphere
CRAN	the steady flow of a viscous fluid past a circular cylinder at reynolds numbers 40 and 44 the steady flow of a viscous fluid past a circular cylinder at reynolds numbers 40 and 44 this paper describes the numerical solution of the complete navier stokes equations for the steady flow of an incompressible viscous fluid of unlimited extent past a circular cylinder at reynolds number 40 a new device developed for the numerical solution is described the results of the investigation are good agreement with experimental results higher reynolds numbers even though they may not exist in nature a solution has been obtained at reynolds number 44 but it has not been carried to the same accuracy as the solution at reynolds number 40 portion of the cylinder continues to increase with reynolds number in such steady state solutions up to a reynolds number 44 and no indication has been found that this process will not continue as the reynolds number is increased beyond 44
CRAN	finite difference formulae for the square lattices finite difference formulae for the square lattices the paper gives approximate formulae for derivatives including combinations like and and integrals of a function of two independent variables in terms of its values at nodes of a square lattice primarily for use in the numerical solution of partial differential equations consideration is given to the form as well as to the magnitude of the leading terms in the error and what is believed to be for most purposes optimum combinations are thus selected for the simpler compact sets of nodes
CRAN	viscous flow round a sphere at low reynolds numbers l40 viscous flow round a sphere at low reynolds numbers l40 relaxation methods are outlined and the present problem formulated in modified spherical polar co ordinates the results of calculations made for r 5 10 20 40 are presented in the form of stream function and vorticity distributions and further results of pressure distributions velocity distributions and drag coefficients calculated from them these results are shown to compare favourably with experimental work showing a steady trend from symmetrical stokess flow towards boundary layer flow the phenomenon of separation of the forward flow and development of a circulating wake is explained and illustrated the first formation of a wake being at r 17
CRAN	numerical solution of the navier stokes equations for the flow around a circular cylinder at reynolds number 40 numerical solution of the navier stokes equations for the flow around a circular cylinder at reynolds number 40 the steady two dimensional flow around a circular cylinder submerged in a viscous fluid for the case r 40 is investigated integrating numerically the exact navier stokes equations the main results are as follows i the steady flow solution exists even for the reynolds number as high as 40 moreover it seems that the solution goes over smoothly to the solution of the kirchhoff discontinuous flow theory which seems to be the limiting flow for the case r ii the flow pattern and the coefficients of pressure and drag are in good agreement with the experimental data
CRAN	the flow past pitot tube at low reynolds numbers part 1 dash the numerical solution of the navier stokes equations for steady viscous axisymmetric flow part 2 dash the effects of viscosity and orifice size on a pitot tube at low reynolds numbers the flow past pitot tube at low reynolds numbers part 1 dash the numerical solution of the navier stokes equations for steady viscous axisymmetric flow part 2 dash the effects of viscosity and orifice size on a pitot tube at low reynolds numbers in this report numerical methods used to solve the navier stokes equations for steady viscous two dimensional flow are extended to include the case of axial symmetry the equations and their finite difference approximations are derived working in cylindrical polar co ordinates with the stokes stream function and the vorticity as variables a new method of dealing with the boundary conditions is given the effects of viscosity and orlfice size on a blunt nosed pitot tube have been theoretically investigated up to a reynolds number of ten where the reynolds number has been based on the radius of the tube results are expressed in terms of a pressure coefficient where p is the pressure measured in the tube p the density of the fluid and p and u the static pressure and velocity in an undisturbed flow at the position of the tube the values of c for a blunt nosed tube are found to be less than those for tubes with hemispheroidal heads but always greater than unity in the range considered the effect of the orifice size is to decrease c as the orifice size increases this decrease is very small but increases with the reynolds number at a reynolds number of ten the decrease is at most five per cent of the value of c when there is no orifice it is suggested that the decrease of c below unity found in some experimental investigations at a higher reynolds number could be due to the effects of orifice size
CRAN	an investigation of fluid flow in two dimensions an investigation of fluid flow in two dimensions flow of an inviscid fluid  dash there are in existence several methods of obtaining numerical solutions to the two dimensional flow of a perfect fluid for given boundary conditions part 2 of the present paper gives a method of obtaining a numerical solution for viscous steady flow solution of the simpler problem illustrating it with examples bearing on the experimental work described in part iv
CRAN	the flow past circular cylinders at low speeds the flow past circular cylinders at low speeds this paper deals chiefly with calculations and experiments on the flow past circular cylinders but the arithmetical methods of solution of the equations of steady viscous flow proposed and used in section i are applicable to other equations and may be of interest
CRAN	note on the convergence of numerical solutions of the navier stokes equations note on the convergence of numerical solutions of the navier stokes equations a criterion is given for the convergence of numerical solutions of the navier stokes equations in two dimensions under steady conditions the criterion applies to all cases of steady viscous flow in two dimensions and shows that if the local mesh reynolds number based on the size of the mesh used in the solution exceeds a certain fixed value the numerical solution will not converge
CRAN	a note on the numerical solution of fourth order differential equations a note on the numerical solution of fourth order differential equations an old numerical method of solving fourth order differential equations is put in relaxation form the higher order correction terms are included and the technique is illustrated by an example the method has the advantage of being more rapidly convergent than the usual relaxation procedure for fourth order equations some comments are made on the numerical solution of the viscous flow equation
CRAN	convergence rates of iterative treatments of partial differential equations convergence rates of iterative treatments of partial differential equations the development of high speed digital computers has made feasible the numerical solution by iterative methods of some partial differential equations the convergence rates of several such iterative methods are estimated here it is found that with the familiar elementary iterative methods some quite simple problems require prohibitive computational labor the iterative methods here considered are related to the various forms of the southwell relaxation method in that they involve successively applied local corrections to improve an approximate solution however these iterative methods are routinized in conformity with the requirements of automatic computers while the relaxation method is flexible and depends in an essential way on the skill of its practitioners
CRAN	iterative methods for solving partial difference equations of elliptic type iterative methods for solving partial difference equations of elliptic type this paper considers linear systems 1 where a includes matrices of a sort frequently occurring in the solution of elliptic partial differential equations by difference methods in particular a o rewriting superscript is number of iteration cycle are used to compute u when u are used also one may over relax ser a 210 307 357 1910 who suggested changing from time to time to speed up convergence in the present paper over relaxation with fixed w is combined with immediate introduction of newly computed us a la gauss seidel various theorems on convergence are proved in particular it is shown that there exists an ordering of the equations and an optimum value wb such that in general 3 converges much more rapidly than the gauss seidel method w 1 means are suggested for estimating wb the sensitivity of the rate of convergence to the choice of w is studied the paper concludes with a theoretical comparison of gauss seidel and the method proposed successive over relaxation for solving dirichlets difference problem over a square using a high speed computing machine
CRAN	aerodynamic characteristics of propeller driven vtol aircraft aerodynamic characteristics of propeller driven vtol aircraft this paper discusses the two major configurations that are usually considered for achieving vtol while keeping the fuselage essentially horizontal   that is the tilt wing and the deflected slipstream configurations because of the high turning losses incurred by deflected slipstream configurations in hovering and because of the wing stalling problem of the pure tilt wing configurations during the transition it appears that a combination of the two principles should be used this tilt wing and flap configuration should make use of a programed extensible chord slotted flap together with a leading edge high lift device in order to avoid the performance and handling qualities problems associated with wing stalling during the transition while keeping the wing area as low as possible for efficiency in cruising flight
CRAN	pressure distribution and force measurements on a vtol tilting wing propeller model pt ii analysis of results pressure distribution and force measurements on a vtol tilting wing propeller model pt ii analysis of results this report presents in graphical form the results presented in reference 1 from pressure distribution and force measurements on a half wing model of a twin engined tilt wing vtol configuration the profound influence of the slipstream on these results is discussed in some detail
CRAN	data from a static thrust investigation of a large scale general research vtol stol model in ground effect data from a static thrust investigation of a large scale general research vtol stol model in ground effect the model was tested at two different elevations with the wing pivot at 1 008 and 2 425 propeller diameters above the ground the slipstream of the propellers was deflected by tilting the wing and propellers by deflections of large chord trailing edge flaps and by combinations of flap deflection and wing tilt tests were conducted over a range of propeller disk loadings from 7 41 to 29 70 pounds per square foot force data for the complete model and pressure distributions for the wing and flaps behind one propeller were recorded and are presented in tabular form without analysis
CRAN	wing nacelle propeller interference for wings of various spans force and pressure distribution tests wing nacelle propeller interference for wings of various spans force and pressure distribution tests an experimental investigation was made in the n a c a full scale wind tunnel to determine the effect of wing span on nacelle propeller characteristics and reciprocally the lateral extent of nacelle and propeller influence on a monoplane wing the results provide a check on the validity of the previous research on nacelles and propellers with 15 foot span wings tested in the the scale propeller and the n a c a cowling used in the former researches were tested in three typical tractor locations with respect to a thick wing of 5 foot chord and 30 foot span the span was progressively reduced to 25 20 and 15 feet and the same characteristics were measured in each case the efficiency factors  propulsive efficiency nacelle drag efficiency and net efficiency  were obtained for each wing length by means of force tests and the values are compared to determine the effect of span pressure distribution measurements show the lateral extent of the nacelle interference and the propeller slipstream effect on the span loading for the various conditions complete polar curves and curves showing the variation of nacelle drag with lift coefficient are also included force and pressure distribution tests concur in indicating that for engineering purposes the influence of a nacelle and of a propeller in a usual combination may be considered to extend laterally on a wing the same maximum distance or about five nacelle diameters or two propeller diameters outboard of their common axes all important effects of scale nacelle propeller combinations may be measured within practical limits of accuracy by tests of a 15 foot span wing
CRAN	induced interference effects on jet and buried fan vtol configurations in transition induced interference effects on jet and buried fan vtol configurations in transition recent investigations of some jet and buried fan configurations have indicated that in the transition speed range configurations with considerable area surrounding the jet or buried fan can encounter large losses in lift and nose up pitching moments due to the pressures induced on the lower surfaces by the interaction of the jet and free stream flow the obvious way of minimizing these effects is to reduce the surface area surrounding the jets or buried fans that is to consider these effects in the preliminary stages of the airplane design
CRAN	investigation of the effects of ground proximity and propeller position on the effectiveness of a wing with large chord slotted flaps in redirecting propeller slipstream downward for vertical take off investigation of the effects of ground proximity and propeller position on the effectiveness of a wing with large chord slotted flaps in redirecting propeller slipstream downward for vertical take off an investigation of the effects of ground proximity and propeller position on the effectiveness of a wing equipped with large chord slotted flaps in redirecting the slipstreams from large diameter propellers downward for vertical take off has been conducted in a static thrust facility at the langley aeronautical laboratory the results indicate that with the propeller thrust axis on the wing chord plane both the angle through which the slipstream is deflected and the ratio of resultant force to thrust are reduced as the ground is approached at positions nearest the ground some of the loss in resultant force is regained lowering the thrust axis below the wing chord plane reduces the adverse effects of the ground and also reduces the large diving moments associated with the slotted flap arrangement the static thrust efficiency of the propellers is slightly reduced by the ground effect
CRAN	investigation of effectiveness of large chord slotted flaps in deflecting propeller slipstreams downward for vertical take off and low speed flight investigation of effectiveness of large chord slotted flaps in deflecting propeller slipstreams downward for vertical take off and low speed flight an investigation of the effectiveness of a wing equipped with large chord slotted flaps in rotating the thrust vector of propellers through the angles required for vertical take off and for flight at very low speeds has been conducted in the facilities of the langley 300 mph 7  by 10 foot tunnel under conditions of static thrust and with zero incidence between the thrust axis and the wing chord plane the slotted flaps were effective in rotating the thrust vector upward about than 10 percent of the thrust when an auxiliary vane was added above the wing the thrust vector was rotated upward configuration vertical take off could be achieved with an initial attitude of 16 and at airplane weights up to 90 percent of the total propeller thrust the addition of 10 incidence between the thrust axis and the wing increased the upward rotation of the thrust vector about 10 for the same turning angle the diving moments associated with the slotted flap configurations were approximately twice as large as the diving moments of the configurations with plain flaps and two auxiliary vanes
CRAN	qualitative measurements of the effective heats of ablation of several materials in supersonic air jets at stagnation temperature up to 11 000 f qualitative measurements of the effective heats of ablation of several materials in supersonic air jets at stagnation temperature up to 11 000 f the effective heats of ablation of a number of materials were derived from tests in supersonic air jets at stagnation temperatures ranging from 2 000 f to 11 000 f the materials included the plastics teflon nylon lucite and polystyrene the inorganic salts ammonium chloride and sodium carbonate several phenolic resins of varied resin content and type of reinforcement and a melamine fiber glass laminate
CRAN	experimental ablation cooling experimental ablation cooling this paper presents the results of an experimental investigation on the ablation of a number of promising materials for heating conditions comparable to those which may be encountered by unmanned reentry satellite vehicles as well as for higher heating conditions comparable to those associated with reentry ballistic missiles materials tested included the plastics teflon nylon and lucite the inorganic salts ammonium chloride and sodium carbonate graphite a phenolic resin and fiber glass composition and the commercial material haveg rocketon results of these tests indicated heat absorption capabilities which are several times greater than those of current metallic heat sink materials the results with teflon showed that for hemispherical noses there was no apparent effect of size or stagnation point pressure on ablation rate for the range of variables covered in the tests for flat faced configurations however there was a definite increase in the ablation rate with increased stagnation point pressure the results for the several materials tested at heating rates associated with reentry ballistic missiles showed considerable increase in the effective heats of ablation over the results obtained at lower heating rates this trend of increased effectiveness with increased heating potential is in agreement with the predictions of ablation theories comparisons of the results for several materials tested at the higher heating rates showed graphite to have the lowest ablation rate of all materials tested
CRAN	an experimental investigation of ablating material at low and high enthalpy potentials an experimental investigation of ablating material at low and high enthalpy potentials the ablation performance characteristics of a number of materials were derived from tests conducted in a mach number 2 0 ethylene heated high temperature air jet having a maximum stagnation enthalpy potential of approximately 1 200 btu lb the tests were conducted with 6  inch diameter blunt nose shapes the surface of most of the materials after testing was generally smooth and the unablated portions of the specimens were in appearance the same as before testing in all cases the back or inside surface of the specimens exhibited no evidence of heating an evaluation of the enthalpy potential effect was obtained by comparison of the present data with previous tests conducted on the in a subsonic arc heated air jet the stagnation enthalpy potential of this facility was approximately 7 000 btu lb for teflon the effective heat of ablation increased from approximately 1 250 btu lb to enthalpy potential was increased from
CRAN	a theoretical study of stagnation point ablation a theoretical study of stagnation point ablation a simplified analysis is made of the shielding mechanism which reduces the stagnation point heat transfer when ablation takes place at the surface the most significant result of the analysis is that the effective heat capacity of the ablation material increases linearly with stream enthalpy the automatic shielding mechanism is discussed and the significant thermal properties of a good ablation material are given parameters
CRAN	an analytical investigation of ablation an analytical investigation of ablation an analytical procedure is described which enables the derivation of effective heat of ablation relationships for any type of boundary layer from transpiration cooling results the procedure enables the inclusion of such effects as the ratio of wall temperature to local stream temperature surface radiation and surface combustion the predicted effective heats of ablation for a three dimensional laminar stagnation boundary layer for teflon material were in agreement with those derived from tests conducted at boundary layer enthalpy potentials of 800 and approximately 7 000 btu lb the predicted equilibrium surface temperatures on nonablating surfaces behind an ablating material were in agreement with the values derived from tests conducted with inconel cylinders having teflon hemispherical nose pieces
CRAN	a sensor for obtaining ablation rates a sensor for obtaining ablation rates a variable capacitance ablation rate sensor which allows continuous measurements of ablation rates for teflon and similar polymers has been developed and tested in an ethylene heated high temperature jet at stagnation temperatures ranging from 2 400degree to 3 800degree f the data length changes were measured by using the same telemeter equipment as that used in rocket propelled flight vehicles test results indicate measurement error to be a maximum of 4 percent between the telemetered length changes and the length changes that were obtained from photographic records of the test
CRAN	a five stage solid fuel sounding rocket system a five stage solid fuel sounding rocket system a five stage solid fuel sounding rocket system which can boost a payload of 25 pounds to an altitude of 525 nautical miles and that of 100 pounds to 300 nautical miles is described data obtained from a typical flight test of the system are discussed
CRAN	pressures densities and temperatures in the upper atmosphere pressures densities and temperatures in the upper atmosphere averaged and internally consistent values of atmospheric pressure density and temperature from the ground to an altitude of 219 km have been determined and compiled by the united states groups active in upper atmospheric research by rockets additional relevant data by similar groups engaged in research on meteors and on the anomalous propagation of sound are also included particularly in a brief discussion of variations with time and with place of these three atmospheric parameters
CRAN	aerodynamic heating of blunt nose shapes at mach numbers up to 14 aerodynamic heating of blunt nose shapes at mach numbers up to 14 results are presented from recent investigations of the aerodynamic heating rates of blunt nose shapes at mach numbers up to 14 data obtained in flight and wind tunnel tests have shown that the flat faced cylinder has about 50 percent the stagnation point heating rates of the hemisphere over nearly the entire mach number range tests made at a mach number of 2 on a series of bodies made up of hemispherical segments of varying radius of curvature showed that slight amounts of curvature can decrease the local rates at the edge of the flat faced cylinders with only a slight increase in the stagnation rate the total heat transfer to such slightly curved bodies is also somewhat smaller than the total heat transfer to flat faced cylinders comparison of several tests with theoretical heating rate distributions showed that both laminar and turbulent local rates can be predicted by available theories given the pressure distribution about the body reasonably well although the scatter of the available data still leaves open the choice between the theories at the edge of the bodies where they usually differ tests on a flat faced cylinder at a mach number of 2 49 and at angles of attack up to 15degree showed the movement of the apparent stagnation point from the center of the body to the 50 percent windward station at creased about 30 percent while that near the leeward edge decreased about 20 percent at 15degree angle of attack preliminary results on a concave nose have indicated the possibility that this type of design may be developed to give heating rates significantly lower than even the flat faced cylinder rates the test results have also shown however the existence of an unsteady flow phenomenon which can increase the heating rates to extremely high values
CRAN	numerical solutions for supersonic flow of an ideal gas around blunt two dimensional bodies numerical solutions for supersonic flow of an ideal gas around blunt two dimensional bodies the method described is an inverse one the shock shape is chosen and the solution proceeds downstream to a body bodies blunter than circular cylinders are readily accessible and any adiabatic index can be chosen the lower limit to the free stream mach number available in any case is determined by the extent of the subsonic field which in turn depends upon the body shape some discussion of the stability of the numerical processes is given a set of solutions for flows about circular cylinders at several mach numbers and several values of the adiabatic index is included
CRAN	free flight observation of a separated turbulent flow including heat transfer up to mach 8 5 free flight observation of a separated turbulent flow including heat transfer up to mach 8 5 a turbulent boundary layer separated by a forward facing step was observed on the cylindrical portion of a hemisphere cone cylinder test vehicle tip blunting producing a shear flow was found to induce higher pressures on the cylindrical portion than were predicted from ballistic tunnel data of unblunted projectiles an approximate method for predicting this blunt body pressure distribution was hypothesized these findings along with the hypothesis were substantiated by a wind tunnel test of a similar body the peak pressure ratios of the separation were smaller in magnitude than flat plate theory predicted because of the effect of the shear flow the decrement in heating of the separated flow relative to the corresponding attached flow was found to compare well with the expected results
CRAN	the flow field over blunted flat plates and its effect on turbulent boundary growth and heat transfer at a mach number of 4 7 the flow field over blunted flat plates and its effect on turbulent boundary growth and heat transfer at a mach number of 4 7 surface pressures impact and static pressure distributions in the flow field over the plate and local heating rates were measured on a flat plate with various leading edge diameters the tests were conducted at a mach number of 4 7 and a free stream reynolds number of 3 8x10 per foot it was found that the shape of the shock wave indicated the existence of an outward deflection of the flow over the plate the flow deflection caused an outward deflection of the shock wave asymptote of approximately the shock wave angle calculated including boundary layer growth the mach number distributions in the shear layer evaluated from pitot and static pressure surveys agreed with predictions based on shock wave shape the predicted turbulent heat transfer coefficients for the blunted flat plates agreed with the measured heat transfer coefficients a comparison between the measured heat transfer coefficients for the blunted flat plates and the calculated coefficients for a sharp leading edged plate indicated that the coefficients were highest near the leading edge of the most blunted plate the measured heat transfer coefficients dropped to approximately 80 percent of the sharp plate values at a considerable distance from the leading edge for all of the blunted flat plates
CRAN	a study of second order supersonic flow theory a study of second order supersonic flow theory an attempt is made to develop a second approximation to the solution of problems of supersonic flow which can be solved by existing first order theory the method of attack adopted is an iteration process using the linearized solution as the first step for plane flow it is found that a particular integral of the iteration equation can be written down at once in terms of the first order solution the second order problem is thereby reduced to an equivalent first order problem and can be readily solved at the surface of an isolated body the solution reduces to the well known result of busemann the plane case is considered in some detail insofar as it gives insight into the nature of the iteration process again for axially symmetric flow the problem is reduced to a first order problem by the discovery of a particular integral for smooth bodies the second order solution can then be calculated by the method of von karman and moore bodies with corners are also treated by a slight modification of the method the second order solution for cones represents a considerable improvement over the linearized result second order theory also agrees well with several solutions for other bodies of revolution calculated by the numerical method of characteristics for full three dimensional flow only a partial particular integral has been found as an example of a more general problem the solution is derived for an inclined cone the possibility of treating other inclined bodies of revolution and three dimensional wings is discussed briefly
CRAN	unsteady laminar compressible boundary layers on an infinite plate with suction or injection unsteady laminar compressible boundary layers on an infinite plate with suction or injection this study deals with unsteady compressible laminar boundary layers on an infinitely extended porous plate an integral solution based on two types of assumed velocity and temperature profiles is presented for the general case where the unsteady free stream velocity and rate of surface suction or injection are both arbitrary also indicated is an exact solution applicable however only to certain specific unsteady free stream and surface suction or injection variations the reliability and range of validity of the integral solutions is then established on the basis of numerical results from the exact solution finally several general qualitative conclusions of the unsteady effects of free stream velocity and surface suction or injection on laminar boundary layer behavior are made
CRAN	on supersonic flow past a slightly yawing cone on supersonic flow past a slightly yawing cone this paper is concerned with the motion of a circular cone of not too blunt an angle through air at high speed if the direction of motion of the cone coincides with its axis of symmetry the resulting air flow is well known here we consider the perturbation produced by a small yaw   i e the case in which the cone is moving not quite in the direction of its axis the results are confirmed experimentally and have applications to ballistics though we are not concerned with the latter here they may also be useful as providing a check on various approximate methods of wider applicability the square of the yaw is neglected  an approximation of which the validity is discussed similar methods can be applied to the second order effects of the yaw which are also of ballistic significance but the computations have not yet been completed it should be observed that because of the lack of symmetry the flow will be neither irrotational nor isentropic
CRAN	some research on high speed flutter some research on high speed flutter paper presents brief discussions of many topics currently of interest in the flutter field these include a the sonic speed case b oscillating pressure field of propellers c wing flutter with various configurations including effects of body modes and d propeller stall flutter
CRAN	unsteady aerodynamic forces on a slender body of revolution in supersonic flow unsteady aerodynamic forces on a slender body of revolution in supersonic flow linearized slender body theory is applied to the computation of aerodynamic forces on an oscillating or deforming body in supersonic flow the undeformed body is a body of revolution and the deformed body is represented by movement of a line through the centers of the cross sections which are assumed to remain circular the time dependence is based on sinusoidal motion for a body of vanishing thickness the slender body theory yields the apparent mass approximation as it is obtained for incompressible crossflow around a cylinder both linearized slender body theory and the apparent mass approximation are used to calculate the pitching moment coefficients on a rigid slender body with a parabolic arc nose cone and these coefficients are compared with some experimental results
CRAN	an electronic apparatus for automatic recording of the logarithmic decrement and frequency for oscillations in the audio and subaudio frequency range an electronic apparatus for automatic recording of the logarithmic decrement and frequency for oscillations in the audio and subaudio frequency range an electronic apparatus for automatic evaluation of the damping of a harmonic oscillation has been designed and constructed the apparatus is based on the idea of representing the harmonic damped oscillation by a rotating vector on the screen of a cathode ray tube in such a way that the rate of decrease of the length of the vector is a measure of the damping the results are obtained simultaneously with the oscillation test as two numbers in decimal digits which are inversely proportional to the logarithmic decrement and the frequency respectively the apparatus which is named the dampometer has been used for some time for free oscillation measurements of the dynamic stability derivatives of aeroplane models in windtunnels and has proved to be very satisfactory it gives results of usually higher accuracy than evaluation methods in common use and permits a most considerable saving of time
CRAN	steady and fluctuating pressures at transonic speeds on two space vehicle payload shapes steady and fluctuating pressures at transonic speeds on two space vehicle payload shapes steady and fluctuating pressures have been measured at mach numbers which were varied from 0 6 to 1 2 on two bodies of revolution typical of two space vehicle payload shapes the centaur and the able v the results of the investigation showed that significant fluctuations of pressure occurred on both bodies between mach numbers of 0 75 and 1 00 the maximum fluctuations measured at any mach number and angle of attack occurred in the region of the normal shock wave as a result of shock wave motion large regions of unsteady pressure also occurred as a result of separation on the converging afterbody of the able v model the maximum pressure fluctuations occurring on the bodies increased with increasing angle of attack for angles other than are indicated since pressure fluctuations were larger on the upper half of the bodies than on the lower half no definite conclusions could be drawn regarding the form of the spectral densities of pressure fluctuations in the region of the shock wave the spectral densities in regions of separation following the shock wave appeared flat except for some increase in energy level below due to slight model motions
CRAN	measurements of aerodynamic forces for various mean angles of attack on an airfoil oscillating in pitch and on two finite span wings oscillating in bending with emphasis on damping in the stall measurements of aerodynamic forces for various mean angles of attack on an airfoil oscillating in pitch and on two finite span wings oscillating in bending with emphasis on damping in the stall the oscillating air forces on a two dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at mach numbers of 0 35 and 0 7 the magnitudes of normal force and pitching moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions large regions of negative damping in pitch were found and it was shown that the effect of increasing the mach number from 0 35 to 0 7 was to decrease the initial angle of attack at which negative damping occurred measurements of the aerodynamic damping of a 10  percent thick and of a 3 percent thick finite span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered the damping measured at high angles of attack was generally larger than that at low angles of attack
CRAN	general instability of stiffened cylinders general instability of stiffened cylinders theoretical buckling stresses are determined in explicit form for circular cylinders with circumferential and axial stiffening the loadings are axial compression radial pressure hydrostatic pressure and torsion analyses were confined to moderate length and long cylinders the investigation was based upon the use of a form of donnells equation derived by taylor which is applicable to orthotropic cylinders the derivation of this equation is presented in this report
CRAN	stability of orthotropic cylindrical shells under combined loading stability of orthotropic cylindrical shells under combined loading the increasing use of fiber and whisker reinforced materials makes necessary the availability of methods of analyzing cylinders and cones composed of an orthotropic material this paper treats the buckling of such shells under a combination of axial compression and uniform external pressure the differential equation approach of flugge is used and the resulting buckling equation is presented in terms of axial and circumferential bending rigidities shear rigidity poissons ratio geometry parameters and mode shapes design curves are presented which allow quick determination of critical loads on cylinders and by using the equivalent cylinder concept on conical shells of small included angle the curves also lend themselves to tailoring of materials to fit the load carrying requirements of the structure
CRAN	elastic stability of orthotropic shells elastic stability of orthotropic shells a small deflection theory for general instability of orthotropic circular cylindrical shells has been derived for external pressure torsion and axial compression for the first two types of loading comparison of the theory with experimental data for orthotropic cylinders reveals agreement comparable with that obtained for isotropic shells for axial compression experimental data have been found to agree reasonably well with theory for orthotropic cylinders in contrast to the agreement usually obtained for isotropic cylinders
CRAN	plastic stability theory of thin shells plastic stability theory of thin shells considerable interest is currently centered on the role of deformation and flow types of plasticity theories in the solution of stability problems for thin flat plates deformation theory combined with classical stability theory appears to yield results which are in substantially good agreement with test data on the other hand flow or incremental theories appear to require the introduction of initial imperfections in order to obtain a satisfactory degree of correlation with tests thus in view of the current state of development of plastic stability theory it appears fruitful to exploit the mathematical simplicity inherent in deformation theory in the investigation of the plastic stability of thin shells although there may be theoretical objections to deformation theories as a class test data on flat plates do suggest the predictive value of the results obtained from this theory in this paper a set of equilibrium differential equations for the plastic buckling of thin shells of constant unequal radii is derived this set of three equations applies to flat plates cylinders and spheres under any loading system leading to buckling for particular problems such as buckling of cylinders under axial compression torsion or lateral pressure and spheres under external pressure the set of equations can be reduced to a single eighth order partial differential equation of the donnell type in terms of the radial displacement only these donnell type equations are used to obtain solutions for plastic buckling of spheres under external pressure and long and moderate length cylinders under lateral pressure or torsion loads the limiting cases of a simply supported flat plate under compression or shear represent the solutions for short cylinders under lateral pressure or torsion respectively
CRAN	a unified theory of plastic buckling of columns and plates a unified theory of plastic buckling of columns and plates on the basis of modern plasticity considerations a unified theory of plastic buckling applicable to both columns and plates has been developed for uniform compression the theory shows that long columns which bend without appreciable twisting require the tangent modulus and that long flanges which twist without appreciable bending require the secant modulus structures that both bend and twist when they buckle require a modulus which is a combination of the secant modulus and the tangent modulus
CRAN	compressive and torsional buckling of thin wall cylinders in the yield region compressive and torsional buckling of thin wall cylinders in the yield region based on assumptions which have led to the best agreement between theory and test data on inelastic buckling of flat plates a general set of equilibrium differential equations for the plastic buckling of cylinders has been derived these equations have been used to obtain solutions for the compressive and torsional buckling of long cylinders in the yield region test data are presented which indicate satisfactory agreement with the theoretical plasticity reduction factors in most cases where a difference in results exists test data are in substantially better agreement with the results obtained by use of the maximum shear law rather than the octahedral shear law to transform axial stress strain data to shear stress strain data
CRAN	on the role of initial imperfections in plastic buckling of cylinders under axial compression on the role of initial imperfections in plastic buckling of cylinders under axial compression in a recent paper lee treated the complex problem of the plastic buckling and postbuckling behavior of an axially compressed cylindrical shell containing initial imperfections representing an important step forward in our understanding of this common yet perplexing structural element lee drew two major conclusions a even with initial imperfections the incremental theory of plasticity considerably overestimates the buckling strength as compared with the deformation theory which is in substantially good agreement with experiments and strength of cylindrical shells subject to axial compression are significant it is the purpose of this note to discuss the second conclusion in terms of lees experimental and theoretical results other experimental data on inelastic buckling of 7075 t6 aluminum alloy cylinders and recent theoretical results on the inelastic buckling of cylinders in the axisymmetric and circumferential modes in particular this writer does not believe that lee has proved that initial imperfections are important for the group of cylinders that he has tested on the contrary it is believed that initial imperfections are completely insignificant for this group of cylinders although of probable significance in other cases
CRAN	an extension of donnells equation for a circular cylindrical shell an extension of donnells equation for a circular cylindrical shell in 1933 donnell succeeded in simplifying the equations of equilibrium for a circular cylindrical shell he obtained simple relations between the critical buckling shearing stress and the physical properties of a thin circular cylinder under pure torsion his approach reduces the tedious computations involved in the classical solutions and is still in good agreement with them furthermore it is easy to show that the well known classical solution for critical compressive stress of the cylinder under axial compression can readily be obtained from donnells equation
CRAN	design of missile bodies for minimum drag at very high speeds   thickness ratio lift and center of pressure given design of missile bodies for minimum drag at very high speeds   thickness ratio lift and center of pressure given newtonian flow theory has been used to develop a procedure for the design of minimum drag bodies of revolution having a given thickness ratio and center of pressure it is shown that the optimum body shape is independent of lift center of pressure location however exerts a powerful influence on both the shape of the body and on the drag coefficient at zero lift
CRAN	collapse by instability of thin cylindrical shells under external pressure collapse by instability of thin cylindrical shells under external pressure this paper discusses the collapse by instability of thin walled cylindrical vessels subjected to external pressure the most important of the theoretical and empirical formulas that apply to this subject are presented in a common notation a new and simple instability formula is developed three classes of tubes are considered tubes of infinite length tubes of finite length with uniform radial pressure only and tubes of finite length with both uniform radial and axial pressure collapsing pressures calculated by the various formulas are presented in tabular form as a means of comparing the formulas the formulas are discussed briefly and checked against the results of tests conducted at the u s experimental model basin for the bureau of construction and repair navy department this paper is a sequel to one previously published as a part of the work of the a s m e special research committee on the strength of vessels under external pressure
CRAN	an engineers conceptual approach to the buckling of cylindrical shell axial loading an engineers conceptual approach to the buckling of cylindrical shell axial loading by using the well known analogy between the bending of a beam on an elastic foundation and the axial symmetric displacement of a cylinder a physical insight is obtained for the buckling of cylindrical shells under axial compression the technique is equivalent to classical small deflection theory and provides good agreement with the more elaborate solutions for the buckling strength of various sandwich multi layered and orthotropic cylinders including the effects of internal pressure or an elastic core
CRAN	the buckling of sandwich type panels the buckling of sandwich type panels fifty one flat rectangular sandwich type panels were tested in edgewise compression with the unloaded edges of the panels restrained by v grooves the sandwich consisted of papreg faces and a cellular cellulose acetate core the thickness of the faces varied from 0 00675 to 0 02025 in the core from 0 066 to 0 741 in the width of the panel from 4 to 11 in the length of the panel was always 10 5 in the buckled shape consisted of a ripple of short wave length across the panel it was either symmetric the two faces bulging out symmetrically according to sine curves or skew the two faces deflecting in the same sense according to sine curves having a phase angle of 90 a strain energy theory of buckling is presented for both the symmetric and the skew cases and the buckling load in the symmetric case is also calculated by integration of the differential equation the agreement between the theoretic and the experimental buckling stress is reasonable that between the predicted and actual buckled shape good a simple formula is developed which permits a choice of the most suitable core material when the mechanical properties of the face material are given
CRAN	face wrinkling and core strength in sandwich construction face wrinkling and core strength in sandwich construction the effect of initial waviness on the wrinkling of faces in sandwich construction is studied formulae are derived to determine the failing stress when the faces wrinkle due to failure of the core in tension compression or shear the importance of core strength requirements in maintaining surface smoothness is noted a comparison of theory with experiments is made and the agreement between the two is found to be reasonably good the strength of the core williams has related the strength of the core in tension and shear to an arbitrarily assumed initial irregularity which to ensure laminar flow in a wing is assumed to have a maximum admissible value initial wave amplitude critical wavelength 0 0005 to 0 001
CRAN	general instability of a ring stiffened circular cylindrical shell under hydrostatic pressure general instability of a ring stiffened circular cylindrical shell under hydrostatic pressure the general instability load of a ring stiffened circular cylindrical shell under hydrostatic pressure is determined by analyzing an equivalent orthotropic shell a set of differential equations for the stability of an orthotropic shell is derived and solved for the case of a shell with simple end supports the solution is presented in terms of parameters of the ring stiffened isotropic shell and a relatively simple expression for the general instability load is obtained some numerical examples and graphs of results are presented in addition an energy method solution to the problem is outlined and the energy and displacement functions that could be used in carrying out a rayleigh ritz approximation are indicated
CRAN	handbook of structural stability pt vi strength of stiffened curved plates and shells handbook of structural stability pt vi strength of stiffened curved plates and shells a comprehensive review of failure of stiffened curved plates and shells is presented panel instability in stiffened curved plates and general instability of stiffened cylinders are discussed the loadings considered for the plates are axial shear and the combination of the two for the cylinders bending external pressure torsion transverse shear and combinations of these loads are considered general instability in stiffened cylinders was investigated for bending and torsion loads test data and theory were correlated for external pressure several existing theories were compared as a result of this investigation a unified theoretical approach to analysis of general instability in stiffened cylinders was developed
CRAN	the effect of axial constraint on the instability of thin conical shells under external pressure the effect of axial constraint on the instability of thin conical shells under external pressure author considers elastic axial restraint which may be 1 active from the beginning of loading and 2 active only at the onset of buckling buckling loads for the two cases are related by a simple conversion factor effect of the restraint on the axisymmetric type buckling is negligible but the amplification of the critical load for the nonaxisymmetric type buckling may be very large for type 1 restraint design curves are included for a range of l d and restraint stiffness results are of doubtful value considering the known inadequacy of the linear theory of buckling under axial compression
CRAN	general instability of ring stiffened cylindrical shells subject to external hydrostatic pressure   a comparison of theory and experiment general instability of ring stiffened cylindrical shells subject to external hydrostatic pressure   a comparison of theory and experiment tests are described of a number of machined stiffened cylinders subjected to external hydrostatic pressure and the observed general instability strengths compared with predictions from theories of kendrick and nash agreement with kendrick was found rather good results also are presented from electrical strain gages which show in detail the growth of embryonic lobes and nonlinear characteristics of deformation at the threshold of buckling weakening effects of imperfect circularity are discussed
CRAN	a simple extension of southwells method for determining the elastic general instability pressure of ring stiffened cylinders subject to external hydrostatic pressure a simple extension of southwells method for determining the elastic general instability pressure of ring stiffened cylinders subject to external hydrostatic pressure a simple extension of southwells method is presented whereby the elastic general instability pressure of ring stiffened cylindrical shells subject to external hydrostatic pressure may be determined an actual application of the method is illustrated in the paper and the results of several other examples are summarized
CRAN	torispherical shells   a caution to designers torispherical shells   a caution to designers it has recently become apparent through a rigorous stress analysis of a specific case that designing torispherical shells by the current edition of the asme code on unfired pressure vessels can lead to failure during proof testing of the vessel the purpose of the present paper is to show in what respects the code fails to give accurate results as an illustrative example a hypothetical pressure vessel with a torispherical head having a diameter thickness ratio of 440 was selected the supports of the vessel were considered to be either on the main cylinder or around the torus the vessel was subjected to internal pressure and the elastic stresses in it were determined rigorously and by the code a comparison of the two revealed that the code predicted stresses in the head which were less than one half of those actually occurring furthermore the code gave no indication of the presence of high compressive circumferential direct stresses which exceeded 30 000 psi for practically the entire torus if the head had been fabricated using a steel with a yield point of would have failed or undergone large deformations whereas the code would have predicted that it was safe the codes rules for torispherical heads are thus in need of revision for certain geometries the implications of the foregoing results are currently being studied by the asme in the interim however designers should exercise care in applying the code to torispherical shells it is also shown in the paper that the use of the membrane state as a particular solution of the differential equations is not a good approximation for toroidal shells of the type considered
CRAN	limit analysis of symmetrically loaded thin shells of revolution limit analysis of symmetrically loaded thin shells of revolution the yield surface for a thin cylindrical shell is shown to be a very good approximation to the yield surface for any symmetrically loaded thin shell of revolution hexagonal prism approximations to this yield surface appropriate for pressure vessel analysis are described and discussed in terms of limit analysis procedures suitable for finding upper and lower bounds on the limit pressure for the complete vessel are developed and evaluated they are applied for illustration to a portion of a toroidal zone or knuckle held rigidly at the two bounding planes the combined end force and moment which can be carried by an unflanged cylinder also is discussed
CRAN	design of thin walled torispherical and toriconical pressure   vessel heads design of thin walled torispherical and toriconical pressure   vessel heads the failure under hydrostatic test of a large storage vessel designed in accordance with current practice stimulated earlier analytical studies this paper gives curves and a table useful for the design and analysis of the knuckle region of a thin torispherical or toriconical head of an unfired cylindrical vessel a simple but surprisingly adequate approximate formula is presented for the limit pressure np at which appreciable plastic deformations occur where p is the design pressure is the yield stress of the material and n is the factor of safety the thickness t of the knuckle region is assumed uniform upper and lower bound calculations were made for ratios of knuckle radius r to cylinder diameter d of 0 06 0 08 0 10 0 12 0 14 and 0 16 and ratios of spherical cap radius l to d of 1 0 0 9 0 8 0 7 and 0 6 toriconic1a heads may be designed or analyzed closely enough by interpreting in table 1 as the complement of the half angle of the cone
CRAN	on the theory of thin elastic toroidal shells on the theory of thin elastic toroidal shells the author obtains asymptotic solutions to the problem of rotationally symmetric small deflection of thin toroidal elastic shells he first reduces the problem to that of integrating a single linear nonhomogeneous ordinary differential equation involving two parameters asymptotic formulae for the complementary function are obtained by applying the general method of langer trans amer math soc 33 advantage of yielding results valid near the points where the tangent plane is perpendicular to the axis of revolution where the methods of asymptotic integration customary in shell theory fail see the preceding review for two problems in which only the complementary function is required the authors results are compared with those obtained by wissler dissertation zurich 1916 by a method of power series expansion the agreement is within 4 or better the author observes that the usual method of obtaining asymptotic expressions for a particular integral being based on using as an approximation the complementary function obtained from the membrane theory will fail near points where the tangent plane is perpendicular to the axis of revolution he therefore introduces a new method which he states was developed jointly with e reissner he applies his results to the cases of an joint loaded symmetrically and parallel to its axis a corrugated pipe subject to axial load and a corrugated cylinder subject to axial pressure many numerical calculations are involved and there are two tables of functions occuring in the solutions
CRAN	asymptotic solutions of toroidal shell problems asymptotic solutions of toroidal shell problems method of asymptotic integration developed by e reissner and author is refined and solutions previously obtained for problems of bending of curved tube and of a toroidal expansion joint subject to an axial force are generalized and extended results are compared to those obtained by l beskin for large values of a certain parameter agreement is good
CRAN	the effect of entrance velocity on the flow of a rarefied gas through a tube the effect of entrance velocity on the flow of a rarefied gas through a tube the flow of a rarefied gas through a circular tube is considered molecules entering the tube have a mass velocity directed down the tube as well as a randomly directed thermal velocity it is assumed that the conditions for free molecule flow hold and that molecules striking the tube wall are reflected diffusely the mass velocity and tube dimensions are restricted only by the limitation to free molecule flow the theory is illustrated by an example of the effect of an entrance tube on the measurement of pressure and density by a gage placed on a satelite
CRAN	shock standoff distance for spherical bodies at high mach numbers shock standoff distance for spherical bodies at high mach numbers usaf sponsored development of a simple expression for shock standoff distance by consideration of an apropriate specific heat ratio behind the shock the theory gives predictions which are almost as accurate as those of the van dyke and hays methods
CRAN	the wake behind an oscillating vehicle the wake behind an oscillating vehicle the incompressible laminar far wake behind an oscillating vehicle is analyzed with the use of the oseen linearization and the assumption that the wake cross section is axisymmetric time wise drag variations are thus represented as changes in the wake diameter and velocity defect it is shown that the unsteadiness in this flow can be predicted by a quasi steady theory
CRAN	effect of wall divergence on sonic flows in solid wall tunnels effect of wall divergence on sonic flows in solid wall tunnels the effect of wall divergence in excess of the normal value given for compensating the boundary layer growth on the tunnel walls on the simulation of sonic flows in solid wall wind tunnels is presented in this note which is a condensed version of ref 1
CRAN	a one foot hypervelocity shock tunnel in which high enthalpy real gas flows can be generated with flow times of about 180 milliseconds a one foot hypervelocity shock tunnel in which high enthalpy real gas flows can be generated with flow times of about 180 milliseconds a shock tunnel is described in which high enthalpy real gas air flows can be generated with flow times of about 180 milliseconds this shock tunnel is operated with a combustion heated driver gas and consists of a combustion chamber shock tube supersonic nozzle test section and vacuum tank an essential feature of this shock tunnel is a means for achieving a constant pressure air reservoir for the duration of the test air streams with velocities in excess of achieved at a mach number of about 10 the corresponding stream total enthalpy is about 4 500 btu lb and the stagnation pressure is 3 25 psia
CRAN	slipstream flow around several tilt wing vtol aircraft models operating near the ground slipstream flow around several tilt wing vtol aircraft models operating near the ground a collection of data from a number of brief investigations made with three different models to determine the character of the slipstream flow along the ground is presented for multiple propeller tilt wing vtol aircraft configurations operating near the ground in general the tests involved tuft surveys and slipstream dynamic pressure measurements for several tilt wing vtol models a more extensive series of tests including some measurements of the erosion of gravel by the slipstream and some measurements of the unsteady rolling yawing and pitching moments was also made on one of the models operating in the hovering condition near the ground the results of the flow studies indicated the presence of a stronger and deeper slipstream flow along the center line of the aircraft and to some extent along parallel planes between adjacent propellers on one wing than to the side of the aircraft this effect is caused by an intensification of the individual slipstreams as they meet at the planes of flow symmetry the intensified flow along the center line of the aircraft is amplified by the presence of the fuselage and causes the dynamic pressure to be greater in front of the aircraft than would be expected on the basis of the slipstream of the individual propellers in the erosion tests it was found that gravel if sufficiently small was rapidly eroded by the slipstream and that this gravel could be thrown high into the air if it struck even very small fixed obstacles on the ground obstacles with a height less than the diameter of the gravel results of the investigation of moment fluctuations indicated that there are large erratic variations of rolling yawing and pitching moments and that the propellers reacting to an erratic inflow from the recirculating slipstream are the primary source of these moments
CRAN	buckling of core stabilized cylinders under axisymmetric external loads buckling of core stabilized cylinders under axisymmetric external loads an equation is derived for the elastic stability of a circular cylindrical shell which is filled with a soft elastic core and is subjected to general axially symmetric lateral pressure combined with a central axial force numerical results are given for three lateral pressure distributions of interest in rocket motor case analysis uniform pressure linearly varying pressure and a circumferential band of pressure located at an arbitrary distance from one end of the cylinder comparison is made with results of previous theoretical and experimental investigations where available
CRAN	thermal buckling of cylinders thermal buckling of cylinders several theoretical and experimental investigations on the buckling of cylinders due to both axial and circumferential thermal stresses are reviewed differences that exist among the various results are discussed and areas of future work are indicated
CRAN	heat transfer to bodies traveling at high speed in the upper atmosphere heat transfer to bodies traveling at high speed in the upper atmosphere a general method has been developed using the methods of kinetic theory whereby the surface temperatures of bodies can be calculated for steady flight at any speed in a rarefied gas the particular solution was made for a flat plate however the calculations can be easily extended to bodies of arbitrary shape it was found that the aerodynamic heating problem in the absence of solar radiation that is for the case of nocturnal flight becomes of negligible importance at altitudes of 125 miles and higher and up to steady flight speeds of 36 000 feet per second the effect of solar radiation for the case of daytime flight becomes increasingly important as the flight altitude is increased at an altitude of 150 miles and higher solar radiation is the predominating factor that determines skin temperature owing to the strong effect of solar radiation on skin temperatures at high altitudes the desirability of nocturnal flight is indicated in order to minimize skin temperatures in order to maintain low skin temperatures it was found that the angle of inclination of the body with respect to the flight path should be kept as small as possible this may be accomplished in practice by designing the body to be finely tapered and by flying the body at small angles of attack it is pointed out that skin temperatures may be reduced by insuring thermal contact between portions of the skin inclined at positive and negative angles with respect to the flight path as much surface as possible should be inclined at negative angles practically this may be accomplished by boattailing the body in the event that an internal skin cooling system is employed it is shown that the rate of internal cooling must be of the same order of magnitude or greater than the rate at which heat is lost naturally by emitted radiation if the cooling rate is below the natural radiation rate cooling has little effect upon skin temperatures it is shown that in the case of a missile designed to fly over a wide range of altitudes and speeds it is desirable to make the emissivity of the skin as high as possible this conclusion however is based upon a skin surface for which the emissivity is independent of the wave length of the emitted and absorbed radiant energy a possible method of reducing surface temperatures is indicated by the decrease in skin temperature which accompanies a decrease in thermal accommodation coefficient this phenomenon may be used to advantage if it is possible to decrease the accommodation coefficient by altering the surface characteristics of the skin
CRAN	knudsen flow through a circular capillary knudsen flow through a circular capillary the problem of knudsen flow through a circular capillary has been often discussed usually by the momentum transfer method however p clausing gave a rigorous formulation for the problem and obtained an integral equation for which he gave an approximate solution from time to time the accuracy of clausings solution has been questioned and since clausing did not give a rigorous estimate of his error we have reinvestigated the problem
CRAN	similar temperature boundary layers similar temperature boundary layers conditions for the existence of similar solutions are known for a two dimensional incompressible steady and nonsteady laminar boundary layers and b three dimensional incompressible steady laminar boundary layers for a body of revolution rotating in a fluid at rest or a body of revolution in a rotating fluid flow corresponding conditions for the existence of similar temperature boundary layers in both cases are given for constant and variable wall temperatures the general conclusion is that in all these cases with or without viscous heating and with constant wall temperature conditions for the existence of similar velocity boundary layers are at the same time the conditions for the existence of similar temperature boundary layers if the wall temperature is variable the conditions for the existence of similar velocity boundary layers are at the same time the conditions for the existence of similar temperature boundary layers if the wall temperature varies as a power of the local free stream velocity or surface velocity numberical solutions are given for the nondimensional temprature distributions function and the nondimensional temperature gradient at the wall for several prandtl numbers in the case of a rotating flow over an infinite plate at rest
CRAN	preliminary results of density measurements from an air force satellite preliminary results of density measurements from an air force satellite atmospheric density was determined from a singly mounted ionization gauge flown on an air force satellite included is a brief description of the experiment and theory as well as a discussion of some of the problems involved in performing these measurements density data are given for the altitude range of 370 to 400 km during early morning hours for the two days 17 and 18 june 1961 results are compared with those of the 1961 revised u s standard atmosphere
CRAN	experiments on supersonic blunt body flows experiments on supersonic blunt body flows recently progress has been made in the theoretical calculation of the inviscid flow between the detached shock wave and the surface of a blunt body travelling at supersonic speed detailed experimental data are needed for comparison experiments have been made in the supersonic wind tunnels of the jet propulsion laboratory on spheres disks and blunted cones over the mach number range 1 8 to 5 0 in air surface pressures shock wave shape and detachment distance certain velocity gradients the sonic line location and some streamline paths were determined the sonic line is found as the trace of the termination point of a weak shock generated by a probe ahead of the model for a sphere good agreement between theory of van dyke and experiment is found
CRAN	on periodically oscillating wakes in the oseen approximation on periodically oscillating wakes in the oseen approximation studies in maths and mechs the oscillating vortex wake behind an obstacle at reynolds numbers of order 10 is studied by means of the oseen approximation
CRAN	a study of the simulation of flow with free stream mach number 1 in a choked wind tunnel a study of the simulation of flow with free stream mach number 1 in a choked wind tunnel the degree to which experimental results obtained under choking conditions in a wind tunnel with solid walls simulate those associated with an unbounded flow with free stream mach number 1 is investigated for the cases of two dimensional and axisymmetric flows it is found that a close resemblance does indeed exist in the vicinity of the body and that the results obtained in this way are generally at least as accurate as those obtained in a transonic wind tunnel with partly open test section some of the results indicate however that substantial interference effects particularly those of the wave reflection type may be encountered under certain conditions both in choked wind tunnels and in transonic wind tunnels and that the reduction of these interference effects to acceptable limits may require the use of models of unusually small size
CRAN	on the influence of wall boundary layers in closed transonic test sections on the influence of wall boundary layers in closed transonic test sections the boundary layers at the test section walls of a transonic wind tunnel are known to reduce the wall interference in the present paper this effect is studied by means of small perturbation theory assuming viscosity to be negligible when perturbing a turbulent boundary layer an approximation for thin boundary layers leads to a modified boundary condition at the wall of the test section expressing the normal streamline slope induced by changes in mass flow density and crossflow within the boundary layer this boundary condition is applied to the linearized equations of subsonic flow and to the non linear transonic equations at choking the cases of plane and circular test sections only being treated in detail the results of linear theory show that all corrections except the three dimensional angle of attack correction are considerably reduced by the presence of the boundary layers at mach numbers greater than 0 9 the essential part of their influence being due to the change of mass flow density with pressure in the case of choking the analysis indicates that the presence of boundary layers will increase the maximum model size for which the flow can be interpreted as corresponding to mach number one in free flight finally the technique of using artificial thickening of the wall boundary layers for a reduction of wall interference is considered though without reaching a definite conclusion as to its value as compared to other techniques
CRAN	some experimental investigations on the influence of wall boundary layers upon wind tunnel measurements at high subsonic speeds some experimental investigations on the influence of wall boundary layers upon wind tunnel measurements at high subsonic speeds pressure distribution measurements and drag determination by means of balance measurements have been carried out for a number of models at high subsonic velocity in wind tunnels where the boundary layer of the walls has been varied within the investigated range it appeared that a thickening of the boundary layer reduced the disturbing influence of the walls which also caused an increase of the choking mach number the phenomenon described should be of a certain importance from the point of view of wind tunnel technique since it is possible to increase the choking velocity for a given model by means of thickening the boundary layer
CRAN	experimental investigation of attenuation of strong shock waves in a shock tube with hydrogen and helium as driver gases experimental investigation of attenuation of strong shock waves in a shock tube with hydrogen and helium as driver gases an experimental investigation has been made of the attenuation of strong shock waves in air in a shock tube time history measurements were made of the static pressure at several stations in the wall of the tube the internal diameter of the tube is 3 75 inches shock  wave velocity data were taken for a distance along the tube of about 120 feet the range of the shock wave mach number covered was from 5 to 10 and the initial pressure ahead of the shock wave varied from 5 to 100 millimeters of mercury hydrogen and helium were used as driver gases a helium driven shock wave was found to decay only about one half as rapidly as a hydrogen driven shock wave the pressure level had little effect on the attenuation rate of a shock wave of given strength for the pressure range investigated the static pressure measurements indicated that a severe pressure gradient existed in the latter portion of the air flow this gradient limits the testing time useful for obtaining reliable aerodynamic data
CRAN	hypersonic shock tunnel hypersonic shock tunnel a hypersonic shock tunnel has been developed for obtaining fluid mechanic information at the high mach numbers and corresponding stagnation temperatures encountered in flight by long range ballistic vehicles and satellites this report describes the hypersonic shock tunnel and presents some of the results obtained in the driven tube and in the nozzle helium is ignited in the driver to produce strong shock waves in air a shock velocity in air as high as 55 000 fps with a calculated equilibrium temperature of 16 000 k has been produced in the driven tube the effects of high stagnation temperatures upon the detached shock wave and the pressure distribution for blunt bodies have been observed in the nozzle test section the detachment distance devreased greatly at high temperatures the pressure distribution for the hemisphere was found to be less than that predicted by the modified newtonian theory shock wave boundary layer interaction at the leading edge of a flat plate was observed and the results agreed with the analytical prediction a detached shock wave was observed for a blunt two dimensional body at very low densities in the test section with a flow mach number of 19 6
CRAN	the tailored interface hypersonic shock tunnel the tailored interface hypersonic shock tunnel the tailored interface hypersonic shock tunnel provides a means for producing the high mach number high stagnation temperature flow conditions encountered in hypersonic flight various gasdynamic phenomena associated with shock tunnels are discussed and experimental evidence of the successful application of this technique is presented as an indication of its research application the results of heat transfer experiments on a hemisphere cylinder model are presented and compared with theory
CRAN	experimental investigation of the effect of yaw on rates of heat transfer to transverse circular cylinders in a 6500 foot per second hypersonic air stream experimental investigation of the effect of yaw on rates of heat transfer to transverse circular cylinders in a 6500 foot per second hypersonic air stream a technique has been developed by which air can be shock compressed by helium to 3660 degrees rankine to generate a 6500 foot per second air stream with a flow duration of 40 milliseconds the resulting equipment is described experiments were conducted to determine rates of heat transfer to transverse circular cylinders of 0 003  greater than 100 the cylinders were tested at a nominal mach number of 11 with a stagnation reynolds number evaluated with free stream mass flow and stagnation viscosity of 4 00 times 10 to the 4th power per foot
CRAN	recent advances in gaseous detonation recent advances in gaseous detonation a review of recent work in gaseous detonation is presented early work is briefly mentioned and treatises listed theoretical calculations of chapman jouguet detonations are reviewed compared and the ambiguity concerning the speed of sound in a reacting gas mixture discussed experimental chapman jouguet measurements are reviewed recent studies of the interior of a detonation wave are presented standing detonation wave research detonation limits two dimensional detonations spectra ionization and magnetohydrodynamic treatments are brought to the readers attention a qualitative description of the development of a flame to a detonation is presented experimental observations are examined and recent theoretical attempts to explain these observations are reviewed
CRAN	stagnation point heat transfer measurements in dissociated air stagnation point heat transfer measurements in dissociated air the results of an experimental investigation of the laminar heat transfer at the stagnation point of a blunt body in partially dissociated air are presented and are compared to the theoretical treatment of fay and riddell heat transfer results are presented for air temperatures as high as 8 000 k where more than periments were performed in a shock tube and the new experimental techniques and principles are discussed briefly simulation of flight stagnation conditions at velocities up to satellite velocity of 26 000 ft sec is shown to be possible in shock tubes and data has been obtained over a large altitude range at these velocities
CRAN	force test investigation of the stability and control characteristics of a 1 8 scale model of a tilt wing vertical take off and landing airplane force test investigation of the stability and control characteristics of a 1 8 scale model of a tilt wing vertical take off and landing airplane a force test investigation has been made to determine the aerodynamic characteristics of a scale model of a tilt wing vertical take off and landing airplane in the short  and long wing configurations the model had two 6 blade dual rotating propellers that were not interconnected mounted on a wing that could be tilted up to an incidence angle of about 90 for vertical take off and landing the investigation included measurements of both the longitudinal and lateral stability and control characteristics in the normal  forward flight transition and hovering ranges tests in the forward flight and transition conditions were made at various wing incidences and power conditions tests in the hovering condition were made in the presence of the ground the data are presented without analysis
CRAN	force test investigation of the stability and control characteristics of a scale model of a tilt wing vertical take off and landing aircraft force test investigation of the stability and control characteristics of a scale model of a tilt wing vertical take off and landing aircraft a wind tunnel investigation has been made to determine the aerodynamic characteristics of a scale model of a tilt wing vertical  take off and landing aircraft the model had two 3 blade single rotation propellers with hinged flapping blades mounted on the wing which could be tilted from an incidence of 4 for forward flight to 86 for hovering flight the investigation included measurements of both the longitudinal and lateral stability and control characteristics in both the normal forward flight and the transition ranges tests in the forward flight condition were made for several values of thrust coefficient and tests in the transition condition were made at several values of wing incidence with the power varied to cover a range of flight conditions from forward acceleration or climb conditions to deceleration or descent conditions the control effectiveness of the all movable horizontal tail the ailerons and the differential propeller pitch control was also determined the data are presented without analysis
CRAN	effect of ground proximity on the aerodynamic characteristics of a four  engined vertical take off and landing transport airplane model with tilting wing and propellers effect of ground proximity on the aerodynamic characteristics of a four  engined vertical take off and landing transport airplane model with tilting wing and propellers an investigation has been made to study the effect of ground proximity on the aerodynamic characteristics of a four engine vertical  take off and landing transport airplane model with tilting wing and propellers tests were made with the wing at an angle of incidence of 90 the position used for vertical take off or landing with the model at various heights above the ground the lift drag and pitching moment were measured and tuft studies were made to determine the flow field caused by the propeller slipstream data were obtained for the complete model for the model with horizontal tail removed and for the wing propeller combination alone the results of the investigation showed that when the model was hovering near the ground there was a strong upwash in the plane of symmetry and also an increase in lift of about 10 percent of the propeller thrust about one half of this lift resulted from an increase in propeller thrust and one half resulted from an up load on the fuselage induced by the upwash as the model approached the ground it also experienced an increasing nose down pitching moment that evidently resulted from the up load on the fuselage the rear part of which was longer than the front part the addition of the horizontal tail which was located about halfway up the vertical tail did not increase the nose down pitching moment because the fuselage decreased the energy of the upwash before it reached the tail
CRAN	an investigation of the effect of downwash from a vtol aircraft and a helicopter in the ground environment an investigation of the effect of downwash from a vtol aircraft and a helicopter in the ground environment dynamic pressure measurement in ground effect have been obtained about a single rotor helicopter and a dual propeller vtol aircraft the results indicate that the slipstream dynamic pressure along the ground some distance from the center of rotation is not a function of disk loading but merely a function of the gross weight or thrust of the aircraft furthermore for a given gross weight the thickness of this outward flowing sheet of air is less for a small diameter propeller higher disk loading propeller the variation of the dynamic pressure flow field for single and dual propellers or rotors is significantly different in the plane of symmetry between the two rotors than in a direction normal to this plane the interaction of the two flows produces a region of upflow in this plane where the fuselage is located and the decay of the maximum dynamic pressure with distance ahead of the fuselage is slower
CRAN	an investigation to determine conditions under which downwash from vtol aircraft will start surface erosion from various types of terrain an investigation to determine conditions under which downwash from vtol aircraft will start surface erosion from various types of terrain results of an investigation with small scale equipment of the conditions under which the downwash from a hovering vertical take off  and landing vtol aircraft will start surface erosion indicate that the onset of erosion depends only on the dynamic pressure of the outward flow of air near the surface for a rotor or propeller at a height of about 1 slipstream diameter above the surface this surface dynamic pressure was found to be equal to the disk loading for the vtol aircraft supported by a ducted fan the surface dynamic pressure with the ducted fan exit at a height of about one half the exit area loading the surface dynamic pressure decreases rapidly with increasing height of the vtol device erosion of sand and loose dirt started at surface dynamic pressures of 1 to 3 lb sq ft which is in general agreement with helicopter experience thoroughly soaking the sand and loose dirt surfaces increased the resistance to erosion to surface dynamic pressures of 30 to 50 lb sq ft spray from water started at surface dynamic pressures of 1 5 to pressures up to about 1 000 lb sq ft
CRAN	an experimental study of the effect of downwash from a twin propeller vtol aircraft on several types of ground surfaces an experimental study of the effect of downwash from a twin propeller vtol aircraft on several types of ground surfaces a full scale twin propeller vtol aircraft with a maximum gross weight of 3 400 pounds has been operated on the ground to study the effect of downwash on several types of ground surfaces static operation over loose snow indicated a zone of obliterated vision ahead of the pilot in an arc of approximately 10 on each side of the plane of symmetry an arc 10 to 45 each side of the center line was found to be an area of fair visibility while the arc from 45 to 90 was an area of poor visibility static operation in the presence of loose surface material indicated that the downwash cleared the area near the aircraft of these particles without recirculation or damage to any components short time operation at moderate forward speed over loose gravel with the thrust axis at an angle of in propeller blade erosion and numerous small dents and fabric punctures in the sides of the fuselage the propeller blade erosion was superficial except for the leading edges where several layers of glass fiber were eroded
CRAN	damage incurred on a tilt wing multipropeller vtol stol aircraft operating over a level gravel covered surface damage incurred on a tilt wing multipropeller vtol stol aircraft operating over a level gravel covered surface a summary is presented of the damage experienced by a tilt wing vtol stol aircraft as a result of operating from a level surface covered with loose gravel the damage was inadvertently incurred as the aircraft was performing a taxiing turn maneuver over an area of level macadam surface containing loose and embedded crushed stone observers from a chase aircraft commented that the wing was tilted at approximately 76 with respect to the ground when the damage occurred deposits of stone in the open fuselage punctures in the rotor blade skin and damage to the compressor blades of the engine occurred due to the circulation of the crushed gravel
CRAN	hangling qualities experience with several vtol research aircraft hangling qualities experience with several vtol research aircraft all of the vtol research aircraft discussed in this paper have successfully demonstrated conversion from hovering to airplane flight and vice versa however control about one or more axes of these aircraft has been inadequate in hovering flight furthermore ground interference effects have been severe in some cases and have accentuated the inadequacy of control in hovering and very low speed flight stalling of wing surfaces has resulted in limitations in level flight deceleration and in descent particularly for the tilt wing aircraft which in this case is a very rudimentary type minor modifications to the wing leading edge have however produced surprisingly large and encouraging reductions in adverse stall effects height control in hovering and in low speed flight has proved to be a problem for the aircraft not having direct control of the pitch of the rotors the other systems have shown undesirable time lags in development of a thrust change
CRAN	structural loads surveys on two tilt wing vtol configurations structural loads surveys on two tilt wing vtol configurations the results of two structural loads surveys are summarized the first loads program discussed concerns the airframe vibratory loads encountered during flight tests of the vz 2 tilt wing vtol aircraft throughout the operational range from hover to cruise flight the primary sources of airframe vibration were wing stall buffeting and tail buffeting in descents the second loads program discussed concerns the initial results of a structural loads survey conducted as part of the wind tunnel test of a large scale tilt wing research model this loads program deals with the steady wing loads measured throughout simulated transition from hover to cruise
CRAN	the stability under axial compression and lateral pressure of circular cylindrical shells with a soft elastic core the stability under axial compression and lateral pressure of circular cylindrical shells with a soft elastic core the stability under axial compression and lateral pressure of a finite circular cylindrical shell with an elastic core is treated by means of donnells equations the stability criterion is investigated in detail for the general cylinder under axial compression or lateral pressure and for a particular cylinder under combined loading comparisons are made with available experimental data
CRAN	elastic stability of circular cylindrical shells stabilized by a soft elastic core elastic stability of circular cylindrical shells stabilized by a soft elastic core the effect of a soft elastic core upon the buckling strength of a thin circular cylindrical shell is investigated experimentally two types of loading are considered a axial compression and b uniform radial band loading where the width of the band is small compared to the length of the shell for each type of loading it is shown that the strengthening effect of the elastic core becomes more significant with the increasing values of the radius thickness ratio for example it is shown that for the geometric and elastic constants considered it is possible with the presence of the core to increase the axial buckling stress by as much as 65 percent over the values found for those without an elastic core the elastic core is even more effective in stabilizing the shell against buckling due to band loading the peak pressure required to buckle the filled specimen being 7 30 times that required to buckle the unfilled shell
CRAN	the buckling of cylindrical shells under longitudinally varying loads the buckling of cylindrical shells under longitudinally varying loads two problems illustrating the effect of nonuniformity of loading on the buckling characteristics of circular cylinders are investigated the first problem deals with the effect of linearly varying axial compressive stress such as would be produced by the weight of the propellant in a solid propellant engine case the results indicate that the ratio of the maximum critical compressive stress induced by the shear load to the critical uniform compressive stress varies from 1 9 for the curvature parameter z equal to 1 6 as z becomes infinite in particular the increase in stress is less than 20 per sq ft for z greater than 100 the stability of thin cylinders loaded by lateral external pressure varying linearly in the longitudinal direction is also investigated the results indicate that for z greater than 100 the buckling coefficients are proportional to square root z
CRAN	general theory of buckling general theory of buckling various aspects of the theory of buckling are expounded in many treatises 1 to 15 the books of bleich 2 and salmon 3 contain large bibliographies goodier developments in buckling theory numerous references are appended to hoffs article nearly all publications on buckling of shells available in the u s a to 1956 are listed in the bibliographies on shells by nash 18 the section ready guide to recent literature
CRAN	stresses from local loadings in cylindrical pressure vessels stresses from local loadings in cylindrical pressure vessels a short discussion is given of the possible methods for computing the stresses caused in cylindrical shells by local loadings it is concluded that the method of developing the loads and displacements into double fourier series leads to formulas which are best suited for numerical evaluation with this method the pertinent expressions for the displacements caused by radial loads are found by reducing the three partial differential equations of the shell theory to an eighth order differential equation in the radial displacements which is similar to but not identical with those derived by donnell and yuan insertion of the fourier series for the radial displacements and the external loading in this equation leads directly to a double series expression of the radial displacement w in terms of the load factors of the radial load this results in the pertinent expressions for the other displacements and for the bending moments and membrane forces the cases of radial loading considered here and those which can be reduced to it are a a load uniformly distributed within a rectangle tion uniformly distributed over a short distance in the circumferential direction d a moment in the circumferential direction uniformly distributed over a short distance in the longitudinal direction for all these loadings the load factors which have to be used in the pertinent formulas for the displacements bending moments and membrane forces are computed for the case of tangential loading an eighth order differential equation is derived in terms of the radial displacement and the tangential load using this equation formulas for the displacements bending moments and membrane forces for tangential loading within a rectangle are found
CRAN	bending tests of ring stiffened circular cylinders bending tests of ring stiffened circular cylinders twenty five ring stiffened circular cylinders were loaded to failure in bending the results are presented in the form of design curves which are applicable to cylinders with heavy rings that fail as a result of local buckling
CRAN	effects of rapid heating on strength of airframe components effects of rapid heating on strength of airframe components results of several experimental investigations are presented which indicate the effects of rapid heating on the bending strength of multiweb beams and ring stiffened cylinders it is shown that thermal stresses reduce the bending load carried at buckling by both beams and cylinders the influence of thermal stress on maximum load is found to depend largely on the mode of buckling for beams that buckle locally no apparent effect of thermal stress on the maximum load has been found a reduction in maximum load has been observed for beams that buckle in the wrinkling mode and for cylinders
CRAN	buckling of ring stiffened cylinders under a pure bending moment and a nonuniform temperature distribution buckling of ring stiffened cylinders under a pure bending moment and a nonuniform temperature distribution thirteen stainless steel ring stiffened cylinders were subjected to a pure bending load and heated rapidly until buckling occurred for most of the cylinders the heating was not uniform around the circumference so that appreciable axial thermal stresses were present elementary thermal stress theory was found to be inadequate for the prediction of these thermal stresses but a method was developed that would give satisfactory thermal stress results by properly accounting for the thermal stress the buckling load could be correlated with a theory for the buckling of an axially compressed ring stiffened cylinder that is uniformly heated
CRAN	a theory of asymmetric hypersonic blunt body flows a theory of asymmetric hypersonic blunt body flows two dimensional asymmetric and three dimensional inviscid blunt body flows are analyzed using a new method the method is inverse that is the shock wave shape and freestream conditions are taken as known and the body shape and flow field are to be determined results at zero angle of attack are obtained as a special case of the general problem solutions at zero angle are calculated for a variety of body shapes at freestream mach numbers ranging from infinity to 1 85 the ratio of specific heats is taken as 1 4 comparison with results obtained using van dykes and garabedians numerical solutions indicates that the method under consideration is more accurate than the van dyke method for determining stand off distance solutions are obtained for parabolic and paraboloidal shock waves at small angle of attack and infinite freestream mach number assumes the values 1 4 1 2 1 1 and 1 05 for all cases the streamline that wets the body passes through the shock wave slightly above the point where the shock is normal and thus does not possess maximum entropy these results provide counter examples to the conjecture that any isolated convex body in a supersonic stream is wetted by the streamline of maximum entropy
CRAN	approximate analysis of the slot injection of a gas in laminar flow approximate analysis of the slot injection of a gas in laminar flow the laminar diffusion and combustion of a gas injected into a high speed uniform stream by means of a wall slot are considered the dorodnitzin howarth transformation is employed to reduce the boundary layer equations to incompressible form the nonsimilar flow field is treated by a modified oseen approximation in conjunction with the integral method thermal boundary conditions corresponding to an adiabatic wall and to constant wall enthalpy are discussed the injection of homogeneous heterogeneous nonreactive and reactive gases is treated for the latter case the models usually employed for chemical behavior namely frozen and equilibrium flow are considered the analysis is applicable to a wide variety of laminar flows e g those involving cooling thermal protection skin friction reduction and supersonic deflagration a numerical example of practical interest in connection with the venting of gaseous hydrogen boiloff from a rocket booster is presented
CRAN	steady magnetohydrodynamic flow past a non conducting wedge steady magnetohydrodynamic flow past a non conducting wedge this paper presents a study of the steady two dimensional magnetohydrodynamic flow of an infinitely conducting fluid past a nonconducting wedge with nonaligned flow and magnetic field the flows considered are in the superfast or fully hyperbolic regime the flows consist of several regions of uniformity connected by shocks and expansion waves because of the boundary condition on the magnetic field the magnetic field must be the same in the regions above and below the wedge thus the flows in these regions are coupled unlike in the case of ordinary supersonic gasdynamics only small wedge angles and weak waves characteristics are considered the problem thus is linearized and explicit solutions are obtained which are qualitatively similar to the nonlinear solutions some interesting and unexpected features arise and they are discussed in detail
CRAN	an approximate solution for laminar boundary layer flow an approximate solution for laminar boundary layer flow this paper presents an approximate solution for two dimensional incompressible laminar boundary layer flow with arbitrary pressure gradient von mises form of the boundary layer equation is linearized by making a change in the coefficient of one of the terms the linearized equation yields a solution that is accurate for the outer portion of the flow but inaccurate near the surface a separate inner solution then is developed which is accurate at the surface and which joins with the outer solution at some point within the boundary layer the method may be considered a major modification of one developed earlier by von karman and millikan with changes in both outer and inner solutions and the point at which the two solutions are joined the changes improve the accuracy of the method and in some respects simplify the calculations as examples results are presented for flow with a linear variation of velocity including flat plate and stagnation point flow as special cases flow with sinusoidal variation of velocity flow past a circular cylinder heimenz velocity distribution and flow past an ellipse schubauers data agreement with theoretically exact solutions is good and better than results obtained using the pohlhausen method
CRAN	laminar hypersonic trail in the expansion conduction region laminar hypersonic trail in the expansion conduction region the usual procedure in calculating the cooling process in a wake behind a blunt object is to assume a region of pure expansion up to a distance where the pressure has reached its ambient value followed by a region where the mechanism of pure heat conduction is operative in the present paper both mechanisms are assumed to be valid simultaneously and the result is compared with previous calculations the following criterion is established the minimum radius of a hemisphere cylinder configuration above which a simultaneous conduction expansion calculation is not needed is given by the approximation where is the nondimensional value of the enthalpy at the axis of the wake below which the two methods of computation give the same result and m is the flight mach number
CRAN	three dimensional effects in viscous wakes three dimensional effects in viscous wakes three dimensionality in wakelike or jetlike free mixing may stem from initial geometric configurations nonuniformities in flow variables over a cross section or boundary conditions along the flow these may be generated by bodies at angle of attack nonaxisymmetric bodies mixing of nonaxisymmetric jets with an outer flow finite wings or more artificial means this paper is devoted to studies bearing on such configurations the first section deals with the general mathematical model in which the boundary layer approximations are used and with methods of solution laminar and turbulent flow compressibility unsteadiness and streamwise pressure gradients are admitted initially the flux forms of the equations are given algebraic integrals of the energy equations and the diffusion frozen flow equations are obtained a simplification of the convective terms roughly corresponding to the oseen approximation is used in the asymptotic downstream region the second section contains explicit solutions for specific configurations in particular for flows whose initial isovels are of elliptic shape these flows may be wakelike or jetlike compressibility is admitted however the flows must have uniform pressure and must be steady the final section deals with interpretation and evaluation of the results
CRAN	an integral method for calculating heat and mass transfer in laminar boundary layers an integral method for calculating heat and mass transfer in laminar boundary layers an integral method previously used successfully in several kinds of boundary layer problems has been extended to treat simultaneous heat and mass transfer in a binary mixture laminar boundary layer when the pressure is uniform the principal results are two pairs of dual integral relations arising from solutions to the integral concentration and energy equations one pair connects the surface mass transfer rate and surface concentration of injected gas the other relates surface temperature and heat transfer rate in the presence of mass transfer only the cases of helium and air injection into an undissociated air stream are discussed in detail but the method can be applied to problems involving other gases the approximate results agree quite well with some numerical solutions and with recent experimental results for which no numerical solutions are available
CRAN	lift of slender delta wings according to newtonian theory lift of slender delta wings according to newtonian theory an approximate system of equations is derived to describe the inviscid flow past a flat slender wing at angle of attack in the limit and the aspect ratio is required to approach zero at the same rate as the mach angle in the flow behind the shock wave only a single parameter appears in the resulting equations and a similarity law therefore can be written expressing a correction to the newtonian normal force coefficient for the delta wing a correlation of experimental data according to the similarity law is shown and the first terms of the solution are derived under the assumption that the similarity parameter is small vertex angle much smaller than mach angle
CRAN	shock induced boundary layer separation in overexpanded conical exhaust nozzles shock induced boundary layer separation in overexpanded conical exhaust nozzles the flow in overexpanded supersonic nozzles is reviewed although five essentially different flow regimes can be discerned depending on the nozzle pressure ratio the regime of most interest to the engine designer is the one characterized by oblique shock patterns in the nozzle and flow separation from the nozzle wall it is shown that the pressure rise associated with the separation correlates well with the mach number at the separation point a simple analytical formulation for the pressure rise required to separate the flow provides excellent agreement with experimental data over a wide range of nozzle operating conditions and allows prediction of overexpanded nozzle performance
CRAN	factors affecting lift drag ratios at mach numbers from 5 to 20 factors affecting lift drag ratios at mach numbers from 5 to 20 yawed cone working charts and an engineering method are presented and used to calculate lift drag ratios of flat top conical wing body arrangements at mach numbers from 5 to 20 viscous interaction effects are considered but bluntness effects are neglected correlations of wind tunnel data in the range show that boundary layer displacement corrections to surface pressure and skin friction are required to calculate lift drag ratios by this method whenever is greater than 0 2 is the freestream mach number and is the freestream reynolds number based on body length double  and single type shock patterns transition from one pattern to the other and the variation of inner shock position with angle of attack are described lift drag ratios are calculated at selected flight design points for flat top conical body arrangements with triangular and hyperbolic wing planforms the hyperbolic wing arrangement offers a potential l d benefit at mach 5 but not at mach 10 or above
CRAN	nonequilibrium flow past a wedge nonequilibrium flow past a wedge an exact numerical solution is obtained for the chemically reacting flow past a wedge the freestream is either in equilibrium or out of equilibrium but nonreacting the attached shock wave is shown to be either concave convex or straight depending on the values of the amount of dissociation in the freestream and a parameter describing the amount of energy contained in the freestream relative to the gas dissociation energy numerical examples are presented illustrating these regimes the flow field is characterized by the presence of an entropy layer and a relaxation layer both easily identifiable in the presentation of the numerical results
CRAN	flow of a gas near a solid surface flow of a gas near a solid surface the state of a gas near a solid surface is investigated it is assumed that at a sufficiently large distance from the surface the particle distribution function is of the chapman enskog form the half range analysis previously employed for parallel plate geometrics symmetric problems can be adapted to the single plate problem although the mathematical analysis differs the slip coefficients are essentially identical with those obtained from the parallel plate problem e g couette flow detailed calculations are presented for both hard sphere and maxwellian molecules the recent work of bakanov and deryagin for hard sphere molecules which is based on incorrect approximations is discussed
CRAN	heat transfer to a hemisphere cylinder at low reynolds numbers heat transfer to a hemisphere cylinder at low reynolds numbers measurements of the local heat flux to hemisphere cylinder models in a supersonic rarefied air stream are presented two different steady state methods were developed and five individual models were used data were obtained throughout the mach number range of 2 to 6 with reynolds numbers based on conditions behind the bow shock and model diameter varying from 38 to 1730 the stagnation point data indicated a gradual increase from continuum boundary layer theory at the higher reynolds numbers to about 10 above at the lower end of the range investigated pressure distribution measurements on cooled and uncooled models were found to agree well with modified newtonian theory local recovery factor measurements showed a small rarefaction effect at the lowest reynolds numbers
CRAN	an integral method for calculation of supersonic laminar boundary layer with heat transfer on yawed cone an integral method for calculation of supersonic laminar boundary layer with heat transfer on yawed cone an integral method for calculating the three dimensional boundary layer over the surface of a cone at angle of attack is investigated the numerical procedure of integration for that method on the basis of a simplifying assumption concerning the boundary layer development along the cone generator is developed and illustrated by applying the method to find the solutions of integral equations for a specific example the results obtained for the example for the range of circumferential angle of 40 investigated are summarized and given as heat transfer coefficients coefficients of friction and other friction parameters the distribution of heat transfer coefficients checked with available experimental data fairly well
CRAN	some exact solutions for cavitating curvilinear bodies some exact solutions for cavitating curvilinear bodies a special case of cavitating flow solutions is postulated and transformed to a semi infinite plane the complete exact solution then is synthesized by superposition of singularities the solution is relevant to a general two parameter family of curvilinear bodies the parameters are the flow angles at the two points of flow separation the body reduces in the special case to the rayleigh solution for a flat plate the equations of the cavity boundaries are given in explicit form the body form and the stagnation streamline are given as the locus of the roots of a cubic equation local static pressures and hence lift and drag also may be calculated the generated solutions constitute a technique involving simple computation for exact solutions of a special family of cavitating curvilinear bodies at finite angles of attack
CRAN	magnetohydrodynamic flow past a thin airfoil magnetohydrodynamic flow past a thin airfoil the steady flow of a perfectly conducting magnetohydrodynamic fluid past a thin nonconducting airfoil is studied with the usual model in which the fluid variables obey the lundquist equations linearized about a constant unperturbed flow hyperliptic flows in which hyperbolic and elliptic fields are superimposed are considered results of grad mccune and resler and sears and resler are extended and considered in detail for the case of an arbitrarily inclined unperturbed field the general solution contains four line singularities along the characteristics through the ends of the body and has two arbitrary constants by a generalized kutta joukowski condition these constants are fixed so that two of the line singularities disappear specifically it is required that the solution be locally square integrable behavior of the exponents of the singularities is investigated by numerical computation and in limiting cases analytically the singular parts of some flows are investigated numerically
CRAN	experiments with two dimensional transversely impinging jets experiments with two dimensional transversely impinging jets experiments on the interaction of transversely impinging two dimensional jet flows were performed in which a low pressure control jet flow interacted with a relatively high pressure power jet flow the ratio of the control jet to the power jet supply chamber gauge stagnation pressure was adjusted at 0 10 and 15 shadowgraphs of the power jet alone as well as the corresponding interacting jet flows were recorded to establish the nature of and changes in the shock structure the jet flows were traversed by a pitot tube to record the pitot pressure distributions at various locations downstream of the power jet exit it was discovered that with the addition of only a small percent control jet flow the normal shock front of the highly underexpanded power jet flow changed to an oblique shock structure and downstream of the previous location of the normal shock which appeared in the power jet flow alone the maximum recovery stagnation pressures were proportionally much higher the mechanism for this behavior of the normal shock is proposed possible practical importance of this behavior of interacting jet flows with reference to aerodynamic noise supersonic diffuser losses etc is also pointed out for the power jet flow alone it was found that by considering the actual jet boundaries as simply an extension of the actual nozzle the average axial flow quantities computed from the area mach number relation using the observed cross sectional area of the jet flow agreed quite favorably with the experimental results
CRAN	growth of the turbulent wake behind a supersonic sphere growth of the turbulent wake behind a supersonic sphere experimental data are presented on the growth of turbulent wakes up to 8000 calibers behind and spheres traveling at supersonic velocities experimental determination of the exponential coefficient in the growth law is very difficult if not impossible data are presented in the form of both in the representation two regions of different wake growths are observed by means of a quasi steady state assumption the effect of drag deceleration is eliminated and growth of the far wake compared with theoretical predictions the agreement with the lees hromas theory in this region was found to be quite good
CRAN	unsteady aerodynamic forces on slender supersonic aircraft with flexible wings and bodies unsteady aerodynamic forces on slender supersonic aircraft with flexible wings and bodies the present paper derives generalized aerodynamic forces for slender supersonic aircraft on the basis of slender body theory particular consideration is given to configurations which are spanwise flexible to treat configurations with flexible wings and bodies the slender wing body problem is first reduced to a simple body problem whose solution is well known and a solution of the latter is obtained utilizing the circle theorem or method of images and a known solution of the airfoil equation for a double interval with this approach it is not necessary to apply conformal mapping techniques and the solution so obtained is valid for arbitrary spanwise downwash distributions on the basis of slender body theory the velocity potential and subsequently the generalized aerodynamic forces are derived for a general class of spanwise flexible wing body configurations
CRAN	the blunt leading edge problem in hypersonic flow the blunt leading edge problem in hypersonic flow the present paper is mainly concerned with the hypersonic flow over a flat plate with a blunt nose the analysis is based on the flow model in which the flow field behind the shock wave may be divided into two regions the inviscid hypersonic flow region and the entropy layer across which the pressure has no appreciable change the equations for the entropy layer can be reduced to those of the usual boundary layer problem with the exception that the outer edge of the entropy layer as well as the pressure remain unknown these unknowns are determined so as to approximately match the entropy layer solution with the inviscid hypersonic solution in which the shock wave has the shape of the power law of the distance from the leading edge the assumed flow model is shown to be valid over a restricted range depending on the wall to stagnation temperature ratio and where is the reynolds number based on half the thickness of nose t m the freestream mach number and c the chapman rubesin constant actual calculations have been carried out for the case with typical values of and the wall to stagnation temperature ratio the calculated values for both the surface pressure and heat transfer rate are compared with the experimental data as regards surface pressure in particular a satisfactory agreement with the data is obtained the validity of the assumptions upon which the present analysis is based has been examined from the numerical results and the region of the validity has been found to extend over a certain large range of the nondimensional distance from the leading edge
CRAN	theoretical investigations of a supersonic laminar boundary layer with foreign gas injection theoretical investigations of a supersonic laminar boundary layer with foreign gas injection the phenomena arising from the uniform injection of helium air argon and iodine into the laminar boundary layer of a supersonic stream of air in a tube were investigated theoretically the partial differential equations describing the energy mass and momentum transfers through the boundary layer were obtained and a series solution was found for the case of uniform injection through the tube wall the results of the analysis are in the form of axial distributions of wall temperature and recovery factor and of radial distribution of concentration velocity static and stagnation temperatures the gas mixture was assumed to be a perfect gas properties of the mixture were calculated in accordance with the gibbs dalton rule and the mixing rules based on the kinetic theory of dilute gases transport properties for pure air were taken from the n b s tabulations transport properties for the other gases were calculated by kinetic theory methods employing a lennard jones 6 12 model for the interaction potential the theoretical predictions for the recovery factor along the tube with air or argon injection agree with experimental data to within one percent the theoretical predictions for helium injection indicate an 8 percent rise in the recovery factor along the tube while experiments have shown only a 1 percent rise these differences between theory and experiment are attributed to inaccuracies in the approximations to the transport properties of the binary mixtures
CRAN	hypersonic viscous flow over a sweat cooled flat plate hypersonic viscous flow over a sweat cooled flat plate this paper presents a theoretical analysis of the hypersonic viscous flow over a sweat cooled flat plate the physical system under consideration is the hypersonic laminar boundary layer over a porous flat plate with homogeneous normal injection of a coolant into the external stream a heat balance at the porous surface is made between the heat transferred to the surface and the heat absorbed by the coolant the existence of similar solutions requires a nonuniform distribution of coolant injection the method of solution consists of the integration of three simultaneous first order equations the momentum and the energy integral equations in the boundary layer and the tangent wedge approximation in the inviscid layer first order asymptotic formulas are given in both the strong and the weak pressure interaction regions for the induced surface pressure the skin friction coefficient and the nusselt number numerical results for three specific cases are presented and discussed
CRAN	a study of slender shapes of minimum drag using the newton busemann pressure coefficient law a study of slender shapes of minimum drag using the newton busemann pressure coefficient law the problem of minimizing the drag of a slender two  dimensional or axisymmetric body in hypersonic flow at zero angle of attack is considered under the assumption that the pressure coefficient law is newtons impact law as modified by busemann in order to include centripetal acceleration effects after the condition that the pressure coefficient be nonnegative is accounted for and after arbitrary conditions are imposed on in addition to the thickness and the length the enclosed area and the moment of inertia of the contour in the two dimensional case and the wetted area and the volume in the axisymmetric case the minimal problem is formulated as a problem of the mayer type and solved by the combined use of the euler lagrange equations the transversality condition the erdmann weierstrass corner condition and the properties of the switching function particular attention is devoted to the class of problems such that among the four quantities being considered two are prescribed while the remaining are free for these problems the extremal arc is composed of two subarcs one is characterized by a positive pressure coefficient and is called the regular shape the other is characterized by a zero pressure coefficient and is called the free layer in this connection the analysis shows the existence of two different types of solutions depending on whether the thickness is given or free if the thickness is given the expression for the regular shape is a power law and the transition from the regular shape to the free layer occurs in the second half of the body in the two  dimensional case the exponent of the power law is 1 if the length is given if the enclosed area is given and 3 if the moment of inertia of the contour is given the transition point from the power body to the free layer is located at 50 percent of the length if the length is given at 66 percent if the enclosed area is given and at the axisymmetric case the exponent of the power law is if the length is given 1 if the wetted area is given and if the volume is given the transition point from the power body to the free layer is located at 60 percent of the length if the length is given at 70 percent if the wetted area is given and at 80 percent if the volume is given on the other hand for problems where the thickness is free the equation governing the regular shape is not that of a power body and the point of transition to the free layer is located in the first half of the body in the two dimensional case the transition point is at 28 percent of the length if the length and the enclosed area are given at 32 percent if the length and the moment of inertia of the contour are given and at 45 percent if the enclosed area and the moment of inertia of the contour are given in the axisymmetric case the transition point is located at 35 percent of the length if the length and the wetted area are given at 39 percent if the length and the volume are given and at 46 percent if the wetted area and the volume are given for all of the cases considered analytical expressions are obtained for the optimum shapes the thickness ratios and the drag coefficients
CRAN	uniformly valid second order solution for supersonic flow over cruciform surfaces uniformly valid second order solution for supersonic flow over cruciform surfaces considered is the second order supersonic flow over a cruciform configuration consisting of two intersecting rectangular wings of high aspect ratio the practical interest is in application to supersonic inlets wing body junctions and vehicle fins the fundamental interest centers about identification and adjustment of the severe local failures of the ordinary second order theory for wings with discontinuous slopes discontinuous potentials occur across the planar shock and square root singularities in the velocities occur at the intersection of these shocks with the cruciform surfaces the problem is simple enough so that these interesting features stand out clearly a second order solution uniformly valid to first order is constructed by adjustment of the ordinary second order solution obtained first the uniformly valid solution has two different series representations in the thickness parameter one is the ordinary second order series in ascending integral powers of the thickness parameter which is valid in the interior of the vertex centered undisturbed mach cone and the other is a series containing fractional powers which is valid adjacent to and upstream of this mach cone the uniformly valid solution gives the detailed wave structure and shows a flow regime upstream of the vertex centered undisturbed mach cone not predicted by the ordinary theory the two solutions are otherwise identical the wave structure consists of a pyramidal arrangement of planar shocks adjacent to and upstream of the above cone followed by weaker oblique expansion fans and finally by two extremely weak shocks coincident with the vertex centered undisturbed mach cone as an example of the above detailed results are presented for the case of two intersecting wedges application of the techniques to other quasi cylindrical problems is discussed
CRAN	the propagation of a nonuniform magnetohydrodynamic shock wave into a moving monatomic fluid the propagation of a nonuniform magnetohydrodynamic shock wave into a moving monatomic fluid an initially uniform magnetohydrodynamic shock wave of arbitrary strength propagates through a channel which consists of two portions of which one has uniform cross sectional area while the other is of varying cross sectional area it is assumed that the flow in the nonuniform section in front of the shock is initially a uniform state and no perturbations due to the area variations of this flow reach the shock until the area variation is encountered when the shock enters the nonuniform section it is perturbed the shock strength altered and the subsequent flow is nonisentropic in addition to the perturbation due to the effect of the area variations on the initially uniform upstream flow there are two further contributions  viz a permanent perturbation caused directly by the area changes and a transient disturbance  which propagates with true sonic speed with respect to the flow behind the shock due to reflections of the permanent perturbation at the shock expressions for these various contributions are obtained the results presented include as special cases propagation of a nonuniform conventional gas dynamic shock into a moving nonconduction fluid and propagation of a nonuniform hydromagnetic shock wave into a stationary fluid
CRAN	experimental effect of bluntness and gas rarefaction on drag coefficients and stagnation heat transfer on axisymmetric shapes in hypersonic flow experimental effect of bluntness and gas rarefaction on drag coefficients and stagnation heat transfer on axisymmetric shapes in hypersonic flow inverted hemispheres circular discs normal to stream spheres 26 total angle 0 368 blunt hemisphere cones 18 total angle sharp cones and other axisymmetric shapes were run in a hypervelocity wind tunnel hypersonic drag coefficients at zero angle of attack were measured in the air velocity range 7 000  efficient is defined as drag force knudsen number is defined as mean free path behind shock sphere shock detachment distance in the case of nonsphere shapes the knudsen number is defined as the knudsen number of a sphere with the same base diameter these drag coefficients cover the range of gasdynamics to free molecule flow and are given in graphical form the drag coefficients were measured by means of a ballistic balance in millisecond intervals and referenced to the drag coefficient of a sphere in the gasdynamics region for a gamma of 1 4 of 0 92 tunnel stagnation conditions of pressure temperature density and pressure drop with time were measured directly in the tunnel test section velocity q density total pressure and static pressure were measured directly these experimental curves have been found useful in the analysis of complex shapes if the complex shapes can be easily broken down into simple components with small interactions between components heat transfer distributions have also been obtained on these and other complex shapes in the hypervelocity wind tunnel by means of a special paint which changes through several visible spectral orders within a heat transfer range of x10 for a single application heat transfer rates so obtained have been performed in the hypersonic gasdynamic and slip flow regions and are presented for spheres these data in the vorticity interaction region agree with the data of ferri and zakkay
CRAN	effects of cooling on boundary layer transition on a hemi  sphere in simulated hypersonic flow effects of cooling on boundary layer transition on a hemi  sphere in simulated hypersonic flow an experimental investigation of the effects of cooling on boundary layer transition on a 9 in diameter hemisphere in simulated hypersonic flow is reported the newtonian pressure distribution was obtained by use of a shroud and boundary layer cooling was achieved by internally cooling the model transition was detected with hot wires and with a pitot tube at the surface attained transition was observed in the subsonic and near sonic flow region at and upstream of n 45 in this region the stagnation reynolds number at which transition occurred when the surface was highly polished was only slightly affected by cooling within the temperature range thus transition reversal does not occur on a polished spherical surface within the range of these tests and we therefore conclude that the cooling did not cause the linear stability of boundary layer to decrease significantly an essential feature of transition studies with boundary layer cooling is the close control of surface roughness in the present experiments this control required in addition to a highly polished surface the necessity for low water vapor dewpoint the avoidance of carbon dioxide condensation and the utilzation of every available means for removing the dust from the airstream
CRAN	magnetohydrodynamic mach cones magnetohydrodynamic mach cones features of the surfaces of main disturbance created by a small object in steady motion through a conducting fluid are examined these surfaces are found by drawing tangent cones from the object to the relevant wave front diagrams the outer wave cone when present is smooth but the two inner cones have cross sections similar to the cusped figures of the inner wave front diagram it is conjectured that the disturbance may be concentrated along such line cusps this has particular relevance in the application of known two dimensional results to three dimensional problems say in the well known techniques of aerodynamics in mhd the omission of the large disturbance characteristics implicit in a two dimensional solution may invalidate its use in any practical three dimensional problem
CRAN	supersonic airfoil performance with small heat addition supersonic airfoil performance with small heat addition an analytical method is presented which permits a very rapid evaluation of the acrodynamic effects arising from the addition of small amounts of heat near supersonic two dimensional airfoils this method applies to shockless inviscid flow without heat conduction also the mechanism by which the sesired heat addition is achieved is not considered it is shown that even small amounts of heat generate a substantial pressure rise and thus cause appreciable changes in the acrodynamic coefficients the results of this analysis compare favorably with those obtained by a more accurate but also more tedious graphical method of characteristics two possible modes of application to an airplane design are considered from the energy requirements standpoint in this connection it is shown that the decrease of the required wing area resulting from heat addition may in some cases lead to savings in the rate of the fuel consumption in general however one should not expect any substantial reduction in energy requirements resulting from the application of the wing heat addition
CRAN	a linearized analysis of the forces exerted on a rigid wing by a shock wave a linearized analysis of the forces exerted on a rigid wing by a shock wave solutions are obtained in closed form for the pressures exerted on a rigid half plane by an incident plane acoustic shock wave the angle of incidence of the wave front is arbitrary and the half plane is considered to be traveling at constant velocity subsonic of supersonic with respect to the acoustic medium a closed form solution is obtained also for a rigid wedge which is motionless with respect to the acoustic medium the analysis is carried out by transforming the wave equation to laplaces equation by the busemann conical transformation and then applying conformal mapping
CRAN	aerodynamic processes in the downwash impingement problem aerodynamic processes in the downwash impingement problem theoretical and experimental data relating to the downwash impingement problem are examined in order to arrive at a coherent understanding of the process of entrainment of ground particles in the flow it is demonstrated that a key mechanism in the process is the interaction of nonuniform flow in the ground boundary layer with bluff ground particles this interaction produces a lift force which under typical conditions equals or exceeds the particle weight in the interest of quantitative prediction of the conditions necessary for particle entrainment four subsidiary problem areas in the impinging jet are examined these are the viscous decay the inviscid flow field the ground boundary layer and the forces on a bluff body in nonuniform flow applicable theories are used in conjunction with experimental data to assess the accuracy and range of validity of the theories and to define the stream conditions which will cause particle entrainment available data are applied to the establishment of criteria for particle entrainment in the vicinity of the impinging jet stagnation point these criteria show that entrainment occurs in a finite annular region on the ground plane and that the particles most readily entrained are those with a diameter equal to about two thirds the thickness of the ground boundary layer the configuration size is shown to influence the process in that the onset of entrainment is fixed by the jet diameter and velocity and the size of the ground particles the criteria established provide a quantitative estimate of the conditions causing entrainment and provide a basis for scaling experimental results to a variety of full scale situations
CRAN	on slender airfoil theory for nonequilibrium flow on slender airfoil theory for nonequilibrium flow an exact linear theory for nonequilibrium flow past a thin airfoil is given greens function technique is used to solve the boundary value problem for the governing third order equation upon satisfying the boundary condition on the airfoil surface an integral equation is obtained which has an exact solution the final expression for the velocity potential given as an integral over the source strength times the greens function shows that the solution is dependent not only on the slope variation of the airfoil but also on its curvature variation this turns out to be the case for all free stream mach numbers as an example the supersonic flow past a wedge is considered
CRAN	boundary layer transition at supersonic speeds three dimensional roughness effects spheres boundary layer transition at supersonic speeds three dimensional roughness effects spheres further experiments carried out in the 12 in supersonic wind tunnel of the jet propulsion laboratory of the california institute of technology to investigate the effect of three dimensional roughness elements spheres on boundary layer transition on a the local mach number for these tests was 2 71 the data show clearly that the minimum effective size of trip required to bring transition to its lowest reynolds number varies as the one fourth power of the distance from the apex of the cone to the trip use of available data for other mach numbers indicates that the mach number influence for effective tripping is taken into account by the simple expression some remarks concerning the roughness variation for transition on a blunt body are made
CRAN	effect of uniformly distributed roughness on turbulent skin friction drag at supersonic speeds effect of uniformly distributed roughness on turbulent skin friction drag at supersonic speeds an experimental program was carried out in the 18 in by 20 in supersonic wind tunnel of the jet propulsion laboratory to determine the effect of uniformly distributed sand grain roughness on the skin friction drag of a body of revolution for the case of a turbulent boundary layer the mach number range covered was 1 98 to 4 54 and the reynolds number varied from about 3 x 10 to 8 x 10 some data were also obtained at a mach number of 0 70 at speeds up to a mach number of 5 and for roughness sizes such that the quadratic resistance law holds the compressibility effect is indirect and the skin friction drag is a function of only the roughness reynolds number exactly as in the incompressible case it is shown that the entire compressibility effect is a reduction of the fluid density at the surface as the mach number increases the critical roughness below which the surface is hydraulically smooth is this is equal to the thickness of the laminar sublayer for a smooth surface for both compressible and incompressible flow over the range of roughness sizes considered here there appears to be no wave drag associated with the drag due to roughness the shift in the turbulent veocity profile for a rough surface at supersonic speeds is a function of only the roughness reynolds number and quantitatively follows exactly the same law as that for the incompressible case
CRAN	heat transfer to slender cones in hypersonic flow including effects of yaw and nose bluntness heat transfer to slender cones in hypersonic flow including effects of yaw and nose bluntness as part of a general study of the aerothermodynamic characteristics of flight of hypersonic vehicles an investigation of laminar heat transfer to slender yawed cones has been conducted experiments have been made in the cal 11  by 15 in shock tunnel at mach numbers from 11 to 13 and at yaw angles up to were tested the heat transfer rates are compared with theoretical predictions the effects on the local heat transfer rates of the boundary layer displacement thickness transverse curvature yaw nose bluntness and the entropy sublayer are discussed it is shown that at zero yaw the experimental data for the sharp cone are in good agreement with theory when boundary layer displacement and transverse curvature effects are included for the yawed sharp cone the heat transfer rates along the most windward streamline are in good agreement with reshotkos theory for yaw angles up to 3 at larger yaw angles the experimental heat transfer was found to be greater than that predicted theoretically however at these yaw angles the heat transfer distribution on the windward side was in good agreement with laminar boundary layer calculations based on an assumption of local similarity the zero yaw tests of the blunted cones showed qualitative agreement with chengs shock layer theory for slender blunt nose bodies
CRAN	the drag of elongated bodies over a wide reynolds number range the drag of elongated bodies over a wide reynolds number range the resistance of bodies in motion through an incompressible viscous fluid is predictable from stokes  or oseen type solutions in the creeping motion range while some test information is available in the boundary layer range with the exception of experimental results for spheres or circular cylinders and analytical and experimental results for flat plates almost no information is available on other bodies particularly in the intermediate range of reynolds numbers extending from unity to a million experimental results as obtained from hydroballistic studies in water and glycerin water solutions are presented for finned ellipsoids of fineness ratio 4 over a 20 000 fold range and are correlated with available information on other bodies although results do not extend down to the creeping motion region where analytical predictions are available comparison with the drag coefficient trends for spheres and flat plates indicates that an appropriate curve for the ellipsoid could be extended so as to cover the entire laminar viscous range less extensive results are presented on the drag of fineness ratio 8 ellipsoids and on laminar turbulent transition occurrences
CRAN	the effect of slip particularly for highly cooled walls the effect of slip particularly for highly cooled walls it is found that for boundary conditions on the velocity slip and on the temperature jump which are not oversimplified in an unrealistic way the effect of these phenomena on the heat transfer and the shear at a stagnation point is of the order of the ratio of the mean free path outside the boundary layer to the boundary layer thickness even for highly cooled walls a simplified theory of this effect is given which puts the physical reasons for the results in evidence and agrees closely with the more accurate calculations it is concluded that the effects of slip and jump are not negligible in comparison with other low reynolds number corrections even for very cold walls
CRAN	pressure distribution in regions of step induced turbulent separation pressure distribution in regions of step induced turbulent separation an analysis is made of the pressure distribution in the separated flow region ahead of a step using the concept of the turbulent mixing coefficient of crocco and lees and the jet flow model of chapman with some modification on the basis of a variable mixing coefficient a differential equation for the pressure distribution is derived which gives the pressure rise as a function of the distance from the separation point this equation contains the separation length as an unknown a second equation is obtained by making a mass balance of the air entering and leaving the dead air region ahead of the step the pressure rise and the separation distance for a given mach number are determined by solving the two equations simultaneously the analysis yields results which are in close agreement with the experimental data on steps obtained at princeton particularly for m 3 85 for lower mach numbers a maximum variation of 5 percent is found between theory and experiment use of the velocity profiles of jets as required by the jet flow model necessarily restricts the applicability of the present study to flows with thin boundary layers at the separation point
CRAN	application of inequality constraints to variational problems of lifting re entry application of inequality constraints to variational problems of lifting re entry inequality constraints are introduced into the variational formulation of the optimum re entry problem for a lifting vehicle to prevent human and or structural tolerances from being exceeded these constraints consist of minimum and maximum angle of attack maximum load factor and maximum convective heat transfer equilibrium temperature the equations have been programed for the ibm 704 computer and sample trajectories are presented for which the total heat transferred to certain critical areas on the windward surface of the vehicle is minimized these trajectories indicate the dominant effect of the constraints on the optimum flight path which is shown to consist of both unconstrained and constrained arcs
CRAN	experimental lift and drag of a series of glide configurations at mach numbers 12 6 and 17 5 experimental lift and drag of a series of glide configurations at mach numbers 12 6 and 17 5 a series of semiballistic type bodies consisting of three half sphere cones of 0 3 bluntness ratio with half cone angles of 8 6 laboratory hypersonic shock tunnel at m 17 5 and 12 4 in addition a representative winged glide configuration consisting of a sharp edged 60 swept delta wing with cone segment the range of angle of attack for the half sphere cone tests was the technique for force coefficient determination consists of analyzing high speed motion pictures of the motion of very light balsa and isofoam plastic models which are literally free flown for several milliseconds in the test section of the shock tunnel because of viscous effects the newtonian prediction of half sphere cone drag is consistently less than but generally parallel these bodies is generally well predicted by the newtonian theory except at small and moderate positive angles of attack where it is generally less than newtonian this lift deficiency appears to increase with cone half angle maximum lift drag ratios fall considerably short of the newtonian predictions several exploratory tests at mach 11 7 and low reynolds number approximately reduction in on the 13 model produced an approximate doubling of minimum drag and a 35 percent decrease in l d max this demonstrates the importance of viscous effects for blunt bodies in the reynolds number range of these tests the sharp leading edge 60 sweep delta wing body configuration exhibited the same l d max as the wing alone about 2 80 at both positive and negative angles of attack
CRAN	determination of lift or drag programs to minimize re entry heating determination of lift or drag programs to minimize re entry heating a study of single pass re entry from escape speed and from circular satellite speed is made to determine the lift program for a hypersonic glider and the drag modulation program for a non lifting vehicle that minimize the heating of the vehicles within acceleration or range constraints a new method of numerical solution is used similar to kelleys method of gradients that permits rapid convergence to the optimum lift program starting with an original good estimate this method avoids the two point boundary value problem of the calculus of variations formulation and is applicable to any optimum programing problem an acceleration tolerance limit is introduced which describes the human pilots capability to withstand acceleration more accurately than a simple acceleration limit
CRAN	boundary layer transition in the presence of streamwise vortices boundary layer transition in the presence of streamwise vortices results of an experimental investigation of instability leading to transition in the subsonic boundary layer flow along a flat plate are presented a series of wings was placed outside the boundary layer to produce streamwise vortices which in turn made the boundary layer three dimensional  i e periodic in thickness in the spanwise direction hot wire measurements were made to trace the downstream development of the disturbance or wave created by the vibrating ribbon as the wave travels downstream it is deformed into a three dimensional configuration by the three dimensionality of the boundary layer flow but it is eventually damped out so long as it remains small in intensity it is only after the wave intensity exceeds a certain amount which depends on the degree of boundary layer three dimensionality that the nonlinear effect manifests itself by the rapid amplification of wave intensity the rapid increase in wave three dimensionality and the distortion in mean velocity profile the appearance of nonlinear development inevitably leads to the breakdown of laminar flow and hence the onset of turbulence there is present a mechanism by which the energy is transferred from one spanwise position to another so that the breakdown of laminar flow occurs as a consequence of three dimensional development of the wave as a whole
CRAN	steady flow of conducting fluids in channels under transverse magnetic fields with consideration of hall effect steady flow of conducting fluids in channels under transverse magnetic fields with consideration of hall effect an approximate method of solution based on a minimum principle is presented for the steady laminar incompressible flow of an electrically conducting fluid through a straight channel of arbitrary cross section with conducting or nonconducting walls in the presence of a uniform transverse magnetic field the hall effect is taken into account by making simplifying assumptions that the gas is fully ionized and that both reynolds number and magnetic reynolds number are small numerical calculations are carried out for the case of a rectangular channel
CRAN	axisymmetric magnetohydrodynamic channel flow axisymmetric magnetohydrodynamic channel flow the axisymmetric subsonic and supersonic flow fields and the skin friction and heat transfer of an electrically conducting compressible fluid flowing in a channel of constant circular area through a magnetic field are investigated when the magnetic reynolds number is small the inviscid flow field for flow through a dipole field is solved by the method of characteristics in the supersonic case for the subsonic case linearized equations are derived for small values of the magnetic interaction parameter numerical results are obtained by the relaxation method the inviscid flow field solutions are used as boundary conditions for the laminar boundary layer along the wall in which axial pressure gradients form an important feature the exact continuum flow equations are reduced by an order of magnitude analysis to the boundary layer equations which are solved numerically by an integral method using a fourth degree velocity profile and a fifth degree stagnation enthalpy profile pressure temperature and heat transfer measurements are made with a shock tube under supersonic flow conditions closely approaching those used in the numerical computations general agreement is found between the theoretical and the experimental results
CRAN	inviscid incompressible flow theory of static two dimensional solid jets in proximity to the ground inviscid incompressible flow theory of static two dimensional solid jets in proximity to the ground the inviscid incompressible flow theory of static two  dimensional solid jets impinging orthogonally on the ground is presented using conformal mapping methods it is shown that the thrust of a solid jet at constant power initially decreases as the ground is approached the magnitude of the thrust out of ground effect is regained only at a very low height to jet width ratio approximately 0 55 the maximuin decrease is about 6 percent the ground effect on solid jets is thus largely unfavorable
CRAN	on the plk method and the supersonic blunt body problem on the plk method and the supersonic blunt body problem detailed analysis of the subsonic and transonic portious of the flow field about either very blunt or asymmetric configurations requires successive approximations these can be carried out in a systematic fashion only when an appropriate convergent perturbation procedure is available the problem of producing successively refined sets of initial conditions for either direct or inverse analysis of the flow is formulated in the following terms given reasonable estimates for shock shape and pressure distribution on the body can one determine the flow field of interest to any desired degree of approximation by a perturbation approach qm a procedure to this effect is developed which involves stretching of coordinates in the spirit of the poincare lighthill kuo are transformed along body shock and intermediate lines so as to annul perturbations of the local resultant velocity b for the integral method the coordinate along the boundary of each strip is shifted so as to control perturbations of the velocity component that determines the critical point the approach is justified by a study of the equations governing the direct method and by consideration of model transonic flow problems for which closed form solutions are available the range of validity of the proposed procedure is assessed by practical application and comparison with experiment results are presented for a disk set normal to a low termperature air stream at m 4 76 and for a highly asymmetric two dimensional configuration at m 8
CRAN	the effect of adverse pressure gradients on the characteristics of turbulent boundary layers in supersonic streams the effect of adverse pressure gradients on the characteristics of turbulent boundary layers in supersonic streams tests were conducted at mach numbers from 2 0 to 3 5 to determine the thickness and profile shape characteristics of turbulent boundary layers on two dimensional and axisymmetric curved surface models having adverse pressure gradients the magnitude of the gradients relative to the boundary layer thickness at the beginning of the gradient was varied by employing models having different radii of curvature and by changing the boundary layer thickness at the beginning of the gradient the overall pressure rise in most cases was greater than the value which would cause a turbulent boundary layer to separate if the pressure rise were created by an oblique shock wave an analytical investigation was also conducted so that the results of the experimental investigation could be applied to the prediction of cases outside the range of the experiments it is shown that boundary layer momentum thickness can be predicted from the von karman boundary layer momentum equation but that measured values of boundary layer profile shape are in poor agreement with values computed from procedures derived by extending conventional methods for predicting profile shape in subsonic flow a new procedure for calculating boundary layer profile shapes developed in this paper is shown to provide a good correlation between experimental and calculated values of boundary layer profile shapes in adverse pressure gradients created by curved surfaces this procedure is based on the experimental observation that the station at which high energy free stream flow actually mixes into a turbulent boundary layer in an adverse pressure gradient is well downstream of the station at which flow would have to mix in order to maintain a flat plate profile
CRAN	heat transfer in the laminar boundary layer with ablation of vapor of arbitrary molecular weight heat transfer in the laminar boundary layer with ablation of vapor of arbitrary molecular weight the reduction of heat transfer in the laminar boundary layer under the condition of vaporizing ablation is analyzed for arbitrary molecular weight of the vapor primary assumptions are that the pressure gradient is zero the individual components of the binary system are perfect gases the prandtl number is constant and the viscosity is proportional to temperature variations through the boundary layer of the schmidt number for binary diffusion and the density viscosity product are included in the analysis the wall temperature is held constant numerical results are obtained for prandtl numbers of 0 75 and varying from 0 25 to 4 00 wall concentration of the foreign gas as high as 0 9 corresponding to the high heat rates encountered during re entry and ratio of specific heats of foreign gas equal to that of air kinetic theory is used to obtain schmidt number as a function of molecular weight and concentration the departure of schmidt number and prandtl number from unity and the variation of reynolds analogy factor with prandtl number blowing parameter wall concentration and molecular weight ratio are found to have relatively minor influence on the heat block ratio at high rates of ablation the primary factor governing the influence of molecular weight ratio on the heat block ratio is the variation of across the boundary layer little loss of accuracy is incurred in the range of molecular weight ratios considered here by assuming schmidt and prandtl numbers of unity as long as the variation is properly taken into account
CRAN	pressure gradient effects on the preston tube in supersonic flow pressure gradient effects on the preston tube in supersonic flow this paper is concerned with an experimental investigation of the effects of a longitudinal pressure gradient in a supersonic stream of air over a bounding surface on the performance of a preston or impact pressure tube at the surface evidence is presented which indicates that for the mach number considered and for the range of pressure gradients covered the preston tube functions in a completely satisfactory manner for the determination of local shear stress
CRAN	leading edge separation of laminar boundary layers in supersonic flow leading edge separation of laminar boundary layers in supersonic flow a brief description of the flow field is given for the interaction of shock wave and laminar boundary layer on a compression corner in supersonic flow a special sub case  that of leading edge laminar separation  is analyzed by extension of chapmans laminar mixing layer theory results are tabulated for ranges of mach number and compression corner angle a limited region of possible leading edge laminar separation with an attached leading edge shock or in certain cases an expansion followed by a second shock due to the reattachment flow is found to exist comparison with existing experimental data is found to be satisfactory in several cases
CRAN	the effect of sweep angle on hypersonic flow over blunt wings the effect of sweep angle on hypersonic flow over blunt wings a series of tests were carried out in the princeton university helium hypersoule wind tunnel on blunt two dimensional wings at zero angle of attack with sweep angles up to 70 at mach numbers from 7 to 15 the leading edge reynolds number varied from 3 000 to 25 000 the measured pressure distributions were compared with the simple summation of the theoretical inviscid effect based on blast wave theory using the normal mach number added to the viscous effect calculated as if no sweep were present for the unswept wing the slope of the pressure decay was reasonably well predicted by the theoretical calculations the viscous theory reasonably predicted the variation in the pressure distribution due to changes in leading edge reynolds number by subtracting the theoretical viscous effects an inviscid mach number dependence of the 2 2 power was found as compared to the value of 2 0 predicted by the inviscid theory the same approach for the swept wing did not give consistently satisfactory results deviations avove and below the calculated value by as much as 40 50 percent were measured and there seemed to be no systematic variation with either mach number or reynolds number at a constant high reynolds number it was found that the pressure distribution varied with the distance along the wing with an exponent between about  0 53 and  0 58 except for a rather sharp decrease which occurred for the 70 sweep case the pressure at a given station for a fixed mach number and given leading edge thickness varied as the cosine of the sweep angle to the 1 1 power as compared to the 1 3 power predicted from general geometrical considerations
CRAN	hypersonic nozzle expansion of air with atom recombination present hypersonic nozzle expansion of air with atom recombination present an experimental investigation on the expansion of high  temperature high pressure air to hypersonic flow mach numbers in a conical nozzle of a hypersonic shock tunnel has been carried out the equilibrium temperature and pressure ranges after the reflected shock wave were 1400 to 6000 k and 100 to 1000 psia static pressure measurements which are sensitive to the state of the gas were made along the axis of the nozzle for different reservoir conditions these results are compared with the calculated equilibrium and frozen data for the same geometry and initial reservoir conditions for reservoir pressures greater than 500 psia the expansion of the air in the nozzle is essentially in equilibrium up to reservoir temperatures of about 4 500 k for temperatures greater than almost frozen at a given area ratio for the nozzle and reservoir pressure the expansion process remains in equilibrium up to a certain reservoir temperature and beyond this temperature the flow expansion deviates rapidly from the equilibrium process and approaches the frozen case
CRAN	hypersonic flow over an elliptic cone theory and experiment hypersonic flow over an elliptic cone theory and experiment by applying hypersonic approximations to ferris linearized characteristics method simple results were obtained for the shock shape and surface pressure distribution for an unyawed conical body of arbitrary cross section calculations were carried out for an elliptic cone having a ratio of major to minor axes of and a semivertex angle of about 12 in the meridian plane containing the major axis an experimental investigation of the flow over this body conducted at a mach number of 5 8 in the galcit hypersonic wind tunnel showed that the surface pressure distribution at zero angle of attack agreed quite closely with the theoretical prediction on the other hand the simple newtonian approximation predicts pressures that are too low surface pressure distributions and schlieren photographs of the shock shape were obtained at angles of attack up to 14 at zero yaw and at angles of yaw up to 10 at zero pitch at the higher angles of attack the newtonian approximation for the surface pressures is quite accurate
CRAN	the curtain jet the curtain jet a detailed analytic study is made of the curtain jet the two dimensional fluid wall used to contain support pressure on the underside of ground effect machines two variations of the jet are studied in detail  the bifurcated jet in which a portion of the flow streams into the support pressure region and the deflected jet in which none of the flow penetrates into the support pressure region kirchhoff helmholtz free steamline analysis is used to construct the flow field and quantitative results are presented for the effect of nozzle inclination and detailed geometry on flow requirements and support pressure differential at varying altitudes
CRAN	supersonic shear flow past an airfoil between two parallel walls supersonic shear flow past an airfoil between two parallel walls the supersonic flow with assigned mach number gradient in the span direction past a straight wing between two parallel walls is studied using the small disturbance theory the governing equation for the disturbance pressure on the airfoil together with the boundary conditions on the airfoil and at the walls is solved by the method of separation of variables upon separation the problem is reduced to a sturm liouville eigenvalue problem and to the solution of the telegraph equation as an application a certain mach number profile is selected and the resulting pressure distribution on a parabolic arc airfoil is computed
CRAN	direct calculation of pressure distribution on blunt hypersonic nose shapes with sharp corners direct calculation of pressure distribution on blunt hypersonic nose shapes with sharp corners the method of belotserkovskii for calculating hypersonic flow fields past a circular cylinder is extended to deal with axially symmetric flow past sharp cornered nose shapes in particular spherical segments and flat headed cylinders results on spheres are also included in the present paper belotserkovskiis first approximation is considered and comparison of calculated pressure distribution and shock shape with experimental results shows very good agreement
CRAN	a theory of the two dimensional laminar bounary layer over a curved surface a theory of the two dimensional laminar bounary layer over a curved surface the purpose of this paper is to present a theory to account for surface curvature effects on the two dimensional boundary layer flow which approaches a potential flow at free stream the problem of two dimensional viscous flow is first formulated by using the streamlines and their orthogonal trajectories as the generalized coordinates a boundary layer approximation is applied to the navier stokes equations and the gauss equation in the generalized coordinates to yield the boundary layer equations the conditions under which similar solutions of the boundary layer equations exist are determined by a simple transformation the governing differential equation can be expressed in a form which reduces to the falkner skan equation for zero surface curvature numerical results for a similar solution which corresponds to a flow over a curved surface with zero surface pressure gradient have been obtained the velocity profiles in the boundary layer and the wall skin friction distribution for concave and convex surfaces are presented the wall skin friction for a convex wall is found to be higher than the blasius value for a flat plate on the other hand for a concave wall the skin friction will drop below the blasius value as the curvature increases but it appears to reach a minimum and beyond this minimum point it will increase again the same flow problem was treated by murphy by a different method of analysis comparison of murphys results with those obtained by the present method reveals some basic differences in the boundary layer characteristics in particular murphys results indicate that the wall skin friction for a convex surface is smaller than the blasius value while for a concave wall it is higher
CRAN	the stagnation point boundary layer in the presence of an applied magnetic field the stagnation point boundary layer in the presence of an applied magnetic field similarity equations for axisymmetric compressible flow are obtained assuming that the magnetic field is uniform normal to the surface and unaffected by the flow and that the conductivity varies as the nth power of the enthalpy numerical solutions are given for a number of values of n and of the field strength and are used to modify the estimates of heat transfer made by the author using inviscid theory title source 26 536 537 1959
CRAN	foreign gas injection into a compressible turbulent boundary layer on a flat plate foreign gas injection into a compressible turbulent boundary layer on a flat plate the distributed injection of a foreign gas into a compressible turbulent boundary layer in the absence of a pressure gradient is considered the analysis is performed within the framework of the binary mixture concept that is the primary fluid flowing over the surface represents one component while the injected species represents the second calculations have been performed for the injection of helium into undissociated air the results indicate an effect of mach number on surface shear and energy transfer when distributed light gas injection normal to the surface exists a comparison with experimental data indicates reasonable agreement over a range of mach numbers
CRAN	the newtonian approximation in magnetic hypersonic stagnation point flow the newtonian approximation in magnetic hypersonic stagnation point flow the hypersonic flow of an electrically conducting fluid around the stagnation region of a sphere carrying a radial magnetic field is examined by assuming a newtonian pressure distribution and constant density the differential equation of the inviscid flow is integrated and a simple closed form solution is obtained it is found that the ratio of the stand off distances of the shock wave for the magnetic and nonmagnetic cases does not depend explicitly on the magnetic parameter s ratio of the ponderomotive force to the free stream inertia force nor on the density ratio the value at the free stream divided by the value behind the shock wave but on the product s at least for values of between and the velocity gradient on the body is also calculated and the ratio of the magnetic to the nonmagnetic case is shown to depend on the parameter the case of cylindrical shocks is also examined the same general conclusions are drawn
CRAN	body under lifting wing body under lifting wing an investigation is made of supersonic aircraft configurations composed of a cambered body positioned a certain distance beneath an arbitrary lifting wing the geometry of the wing is regarded as given and the geometry of the body may be given or optimum expressions for the drag and lift are obtained from reverse flow considerations these greatly implement such a study when interference cross flows must be cancelled the drag advantage to be gained when a given body and wing assume a given orientation is studied treated more extensively is the variational problem of determining the optimum wing incidence and optimum body shape for the given volume and length to yield the minimum drag for prescribed lift numerical results are provided to indicate the significance of the large number of parameters appearing in the problem of these the gap between the wing and the body is found to be particularly important it is found that at low gap moderate body distortions have a significant influence on the drag drag reductions of up to 44 relative to the case of no interference have been found at a mach number of 2 24 in a configuration having a gap approximately equal to the maximum diameter of the body and a wing chord of about three eighths of the length of the body comparison is made with the conventional wing body combination including the effects of skin friction and it is concluded that the advantage suggested by the preceding considerations is not appreciably diminished finally it is shown that the configurations studied lead to bodies of fineness ratios much lower than are appropriate to conventional wing body combinations tests were made on an arrangement consisting of a scars haack body located under a lifting rectangular diamond profile wing the mach number was 1 6 and the reynolds number was 9 17 x 10 based on the body length it was found that the measured lift developed on the wing due to the flow field of the body agrees very well with the theoretical value downstream of the impinging shock from the wing flow separation was observed on the exterior of the body but not in the interior the separation is attributed not to the pressure rise across the shock but to the pressure field arising from the reflection from the body of the shock induced cross flow further observations suggest that the separation can be avoided by pitching the body or by kinking the body at the shock wave to accommodate the shock induced cross flow
CRAN	nonsimilar solutions of the compressible laminar boundary layer equations with applications to the upstream transpiration cooling problem nonsimilar solutions of the compressible laminar boundary layer equations with applications to the upstream transpiration cooling problem a new method is presented for predicting the boundary layer characteristics downstream of the porous region of an injection cooled surface the method consists of a general scheme for obtaining nonsimilar solutions of the compressible  laminar boundary layer equations and is formulated along the following lines the viscous domain is divided into n curvilinear strips the governing equations are then integrated along the coordinate normal to the body from the surface to the boundary of each strip as a result one obtains a set of independent integro differential relations the integration is carried out by expressing the integrands as polynomials the coefficients of which are functions of the unknown values of the velocity and temperature on the strip boundaries as well as of the imposed boundary condition at the wall and at the outer edge after the integration is performed a set of ordinary first order differential equations is obtained the set of equations may be solved for given initial conditions by a numerical integration scheme such as the runge kutta method several numerical examples of interest are presented
CRAN	the turbulent boundary layer on chemically active ablating surfaces the turbulent boundary layer on chemically active ablating surfaces incompressible turbulent boundary layer analysis is extrapolated analytically to the case of a compressible turbulent boundary layer with ablation or mass injection at the surface the effects of chemical reactions such as dissociation and recombination as well as combustion are included the analysis applies to blunt as well as sharp bodies which are either axisymmetric or two dimensional when the turbulent lewis and prandtl numbers are unity it is found that as in the laminar case little detailed knowledge of the chemistry inside the boundary layer is required in most instances the conditions at the surface and the outer edge of the boundary layer are often sufficient for prediction of heat and mass transfer comparison is made with experiments on the combustion of graphite under turbulent flow conditions prediction of ablation rates within about 30 percent accuracy is obtained when empirical constants obtained from incompressible velocity profiles with no mass injection are used
CRAN	some considerations on the laminar stability of time dependent basic flows some considerations on the laminar stability of time dependent basic flows as a stability criterion for infinitesimal disturbances in an incompressible parallel but time dependent basic flow it is proposed to introduce the concept of momentary stability which is said to prevail at the instant if the kinetic energy of the disturbances as a fraction of the kinetic energy of the basic flow tends to decrease the significance of such a criterion is briefly discussed for special time dependent basic flows which are described by similar velocity profiles at all times except for changes in amplitude in the inviscid limit only a change of the time scale is needed to reduce the solution essentially to that for the steady case the disturbances may be of either the transverse wave or the longitudinal vortices type the result indicates a very strong destabilizing influence of deceleration which is likely to overshadow that of the velocity profile under normal circumstances the observations of fales rotating cylinders are believed to be largely due to the deceleration at finite reynolds numbers the usual procedure of calculating the stability solution on the basis of the instantaneous profile is further shown to be valid only for extremely slow acceleration or deceleration even when the solution is acceptable the condition for neutral stability may not be used without reservation to calculate momentary stability properly a procedure for a slowly varying but more general profile is also described
CRAN	supersonic boom of wing body configurations supersonic boom of wing body configurations the supersonic boom in steady level flight of a wing body configuration is due to the effects of body volume wing volume wing incidence or lift and wing body interference the contribution in the far field of each of these factors can in any given azimuthal plane be represented as that of an equivalent body of revolution this concept is developed to investigate the possibilities of using interference among the components of a wing body configuration to reduce or suppress the boom due to lift results of wind tunnel experiments are also presented and discussed in light of the theoretical indications
CRAN	on the aerodynamic noise of a turbulent jet on the aerodynamic noise of a turbulent jet a new model is advanced for analyzing the broad spectrum noise of a turbulent jet the shear layer bounding the turbulent jet is assumed to play an important role in modifying the quadrupole sound radiation from the interior to the sound  emitting small scale turbulent eddies with frequencies much higher than those of large scale eddies the laminar shear layer has an irregular contour as if the large scale turbulent motions were frozen the linearized analysis is then applied to the laminar shear layer to relate the acoustic oscillations across it the concept of geometrical acoustics is generalized to represent the passage of an acoustic ray through a laminar shear layer acoustic rays may be traced across the shear layer as transmission and refraction but they may also be apparently absorbed or generated by the laminar layer this generation is visualized as the schematic representation within the framework of geometrical acoustics of the action of the reynolds stress in transferring energy from the shearing mean flow to the acoustic waves such action of the reynolds stress can be neglected in ordinary acoustics when the acoustic medium is not moving at speeds comparable to the speed of sound in the medium however this action is of crucial importance in the aerodynamic noise of high speed turbulent jets where the reynolds stress is the fundamental element of the radiating quadrupoles according to lighthill those acoustic waves that become stationary with respect to the local mean flow somewhere in the interior of the shear layer are significantly modified by the viscous action through the critical layer the shear layer therefore serves as a selective amplifier of the acoustic waves passing through it kinematically the shear layer brings about the preferred downstream emission dynamically the shear layer augmentation significantly increases the polar peak noise level the acoustic power output per unit solid angle for such downstream emissions augmented by the shear layer including the polar peak varies as predicted by lighthill but without lighthills convective corrections on the other hand the acoustic power output per unit solid angle nearly normal to the jet due to the transmitted downstream propagating waves varies roughly as heating the jet gas increases the shear layer augmentation and may increase the polar peak noise level by several db the silencing action of the edge notches and edge teeth may also be interpreted as due apparently to the result of possible distortion of the shear layer profiles
CRAN	some aspects of nonequilibrium flows some aspects of nonequilibrium flows in this paper are discussed some of the general features of nonequilibrium flow in particular vibrational relaxation is discussed in detail this case is somewhat simpler than dissociation and ionization but it illustrates some of the main new features of nonequilibrium flow those aspects of two dimensional and axisymmetric flow behind shock waves are examined analytically which yield significant information without requiring numerical solution of the governing equations the thermodynamics of a vibrational relaxing gas are discussed the conditions for simulating flows are noted croccos theorem and the characteristic equations are derived then a simple method of obtaining the initial gradients of the flow variables behind a shock is shown these gradients are used in discussing two particular flows an exact solution for flow over a cusped body is obtained flow over a wedge near the tip and far from the tip is considered it is found that far from the tip a boundary layer type phenomenon occurs
CRAN	solution of subsonic nonplanar lifting surface problems by means of high speed digital computers solution of subsonic nonplanar lifting surface problems by means of high speed digital computers the method proposed in this paper is based on an approximate solution of the integral equation which represents the potential flow about a finite wing with no restrictions beyond those necessary for linearization after assuming the usual series representation of the wing surface vorticity distribution the solution is achieved by approximating portions of the kernels of the transformed integral equation by single and double fourier series and performing termwise integrations analytically this is followed by the routine inversion of the aerodynamic influence coefficient matrix after satisfying appropriate boundary conditions at selected control points in this procedure the number of control point used is limited only by the storage capacity of the computer control points may be located so as to cover the entire wing surface with due regard to certain physical requirements permitting the accurate representation of complicated mean surface shapes an evaluation of the proposed method is included comparisons with other theoretical methods and electrical analogy tank results are used to substantiate the accuracy of the proposed method when applied to plane wings a final evaluation involves a comparison of calculated surface pressure distribution with wind tunnel measurements on a swept tapered wing with a cambered and twisted mean surface the agreement evidenced in the latter comparison has the same order of overall accuracy as similar comparisons on plane wing planforms in either case the results given by the proposed method are within the accuracy requirements for most aircraft design studies
CRAN	the supersonic boom of a projectile related to drag and volume the supersonic boom of a projectile related to drag and volume the whitham theory predicting the far flow field around a projectile is used to derive body shapes which produce extreme bow shock wave pressure jump or boom subject to constraining conditions regarding the drag due to the bow shock and fineness ratio of the bodies it is found that the minimum drag body is also the minimum boom body the body volume effect and the effect of discontinuities in slope of the body meridian section on the boom intensity is investigated as a general result of the investigation it can be said that the boom of a projectile for given mach number and flight altitude is primarily determined by its length and fineness ratio the maximum variation in the boom intensity for pointed bodies with given length and fineness ratio is of the order of 10 per cent the geometry of the bodies is thus found to play a minor role
CRAN	an analytic extension of the shock expansion method an analytic extension of the shock expansion method the problem is considered of calculating approximately the inviscid rotational flow field and pressure distribution about a smooth two dimensional airfoil with sharp leading and trailing edges in a uniform supersonic or hypersonic stream the assumption of a perfect gas is made and the basic flow pattern for the analysis is taken to be given by the simple isentropic shock expansion method with straight characteristics an elementary characteristics treatment is discussed to show when the simple shock expansion method should be satisfactory for computing the surface pressure distribution and under what circumstances it may be expected to break down by utilizing characteristic variables the isentropic shock expansion method is then formulated analytically and an analytic result is obtained for the shock shape corresponding to this zero order approximation in the special case where hypersonic similitude is applicable that is for slender bodies and high mach numbers the shock shape expression for large distances is found to reduce to the result previously given by mahony which for weak shocks and slender bodies in turn reduces to the simple wave result first given by friedrichs employing the analytic form of the isentropic shock expansion method as a zero order approximation an analytically consistent perturbation method is developed by expanding the dependent flow variables in the exact partial differential equations in powers of the reflection coefficient for simple waves interacting with an oblique shock the scheme by its nature helps to define those regions in which shock expansion can be used in addition to taking into account in a perturbation sense the factors neglected in simple shock expansion theory namely the curvature and reflection of the mach waves and the correct boundary conditions at the shock wave analytic solutions are obtained for the first order corrections including the surface pressure distribution the necessary numerical computation of the integrals involved is considerably simpler than a direct application of the method of characteristics to illustrate the method and its accuracy the zero order shock shape and first order pressure distribution are calculated for a family of parabolic arc airfoils at an infinite free stream mach number these results are compared with rotational characteristic solutions where available and the present method is found to be in excellent agreement
CRAN	plasma flow over a thin charged conductor plasma flow over a thin charged conductor the flow of a dense plasma over a wavy conducting wall of small amplitude is investigated where magnetic effects are negligible these results are then used to analyze the flow over a thin conductor with cusped edges it is found that the coulomb drag vanishes identically while the fluid pressure drag corresponds to the ackeret value for a neutral particle gas at the reduced plasma mach number
CRAN	high speed viscous corner flow high speed viscous corner flow a boundary layer integral method analysis is set up for compressible laminar flow in a symmetric corner with varying angle and streamwise pressure gradient it represents an extension and modification of the constant density analysis of loitsianskii and bolshakov the analysis is applied to the case of constant pressure constant corner angle and isothermal surfaces for which the crocco velocity enthalpy relation holds although simplifying assumptions limit the quantitative accuracy outside the 60 to 120 angle range some qualitative trends are probably correct outside this range the limiting cases near 0 and 180 are not considered favorable agreement between some results obtained by the integral method and by other methods is demonstrated for the isothermal constant density case results show an increasingly sharp merger of the outermost isovels of streamwise velocity as the mach number increases this sharp merging of the outer isovels is increased by increasing corner angle and by insulation of heating of the surfaces within the interior of the viscous layer the spreading or contraction of the disturbed region of merging is influenced by surface heat transfer conditions surface shear and heat flux are decreased in the disturbed region and are zero at the apex for cases corresponding roughly to the higher mach numbers of wider corner angles the specific momentum area exhibits the same decrease with mach number as its two dimensional counterpart whereas the specific displacement area a measure of stream tube dilation increases more rapidly with mach number than the comparable two dimensional parameter
CRAN	viscous flow past a quarter infinite plate viscous flow past a quarter infinite plate a study is made of the motion of an incompressible viscous fluid past a quarter infinite plate whose leading edge is perpendicular to and whose side edge is parallel to the undisturbed direction of the stream it is assumed that the kinematic viscosity is small the first approximation is taken to be the undisturbed motion and successive approximations are obtained by iferation the second approximation is the blasius shear layer necessary to satisfy the boundary conditions on the plate in turn this layer leads to a velocity component normal to the plate which needs a potential solution in which the velocities are 0 to match with the conditions at infinity further the match at the edge of the blasius shear layer must be completed to 0 by introducing a secondary shear layer the regions near the leading and side edges are considered separately in particular the neighborhood of the side edge needs special care because the determination of the chief terms is complicated by the presence of powers of log in particular it is shown that the effect of the edge is to change the skin friction coefficient by a factor
CRAN	on the approach to chemical and vibrational equilibrium behind a strong normal shock wave on the approach to chemical and vibrational equilibrium behind a strong normal shock wave the concurrent approach to chemical and vibrational equilibrium of a pure diatomic gas passing through a strong normal shock wave is investigated it is demonstrated that the equilibrium degree of dissociation behind the shock front and hence the density for the case where the vibrational degrees of freedom are frozen out can exceed the degree of dissociation and hence the density for the case where all degrees of freedom are in equilibrium thus the necessary condition for a maximum of the density between the shock front and the position of full equilibrium flow downstream of the shock front is established the sufficient condition that such a maximum be observable is shown to be that the approach to equilibrium of the vibrational degrees of freedom or any other internal degrees of freedom must lag the approach to dissociation equilibrium by a significant amount that is there must be at least an order of magnitude difference in the respective relaxation times before such a maximum might be observed an example calculation for a mach 13 strong shock wave in oxygen illustrates the appearance of such a maximum of the density and its dependency upon the relative values of the vibration and dissociation relaxation times
CRAN	hypersonic viscous flow near the stagnation point in the presence of magnetic field hypersonic viscous flow near the stagnation point in the presence of magnetic field the present study investigates the hypersonic viscous flow past blunt nosed bodies with hydromagnetic interaction local similarity solutions of flow field and temperature distribution are near the stagnation point region the discussions may be grouped into two parts the two dimensional problem circular cylinder and axisymmetric problem sphere numerical computations have been carried out for the sphere problem for the viscous layer regime with various magnetic field strengths and electrical conductivities
CRAN	combustion in the boundary layer on a porous surface combustion in the boundary layer on a porous surface the position of the diffusion flame in a boundary layer with uniform mixture injection from a porous wall parallel to a uniform air stream is determined under the conditions of laminar steady flow with zero streamwise pressure gradient under the assumption of fast forward reaction rate solutions of the boundary layer forms of the conservation laws of acrothermochemistry are obtained leading to a formula for the downstream velocity at the flame in terms of composition and flow variables the rates of change of conditions at the wall in the streamwise direction are assumed to be relatively small methods of treating complex reaction systems are described and generalized form of the reynolds analogy is developed
CRAN	the flow about a charged body moving in the lower atmosphere the flow about a charged body moving in the lower atmosphere the flow about an electrically charged body traveling at high speeds through the lower ionosphere is analyzed a simple gas model composed of electrons ions and neutral particles is used and the hydrodynamic description given is based on maxwells transfer equations for a mixture the conditions under which local statistical equilibrium can be assumed are discussed and different approaches to determine the gasdynamic force in the subsonic supersonic and hypersonic cases are indicated the reciprocal action of the electric field of the flow on the body is also analyzed and a formula for the resultant electric force is given the total force on the body is equal to the sum of the gasdynamic force and the electric force the negative potential acquired by a plane body is also calculated finally the lack of validity of debyes linearization in this case and the solution of the exterior nonlinear problem which characterize the electric potential and the electron distribution are discussed
CRAN	fluctuating lift and drag acting on a cylinder in a flow at supercritical reynolds numbers fluctuating lift and drag acting on a cylinder in a flow at supercritical reynolds numbers the fluctuating lift and drag acting on a circular cylinder in a flow of an incompressible fluid at large reynolds numbers were measured data on the root mean square values of the lift and drag coefficients the extreme values of these coefficients and their power spectra at various reynolds numbers are presented
CRAN	an optical boundary layer probe an optical boundary layer probe the applicability of the schlieren photomultiplier technique to obtain quantitative density measurements in the laminar boundary layer induced by a traveling shock wave in a shock tube is investigated tests were conducted at a mach number of 1 58 so that the data could be compared with the exact theoretical solution tabulated by mirels the data obtained are in good agreement with the theory if the distance of the light beam above the floor of the shock tube is adjusted to fit the theoretical curve this would not be necessary if a larger shock tube were used values of the transition reynolds number were also determined which are slightly less than those found by martin using an interferometer it is shown that this technique is sensitive enough to detect changes in density that are only 0 000 per cent of atmospheric density
CRAN	heat transfer recovery factor and pressure distributions around a circular cylinder normal to a supersonic rarefied air stream heat transfer recovery factor and pressure distributions around a circular cylinder normal to a supersonic rarefied air stream measurements of the heat transfer recovery factor and pressure distributions around a circular cylinder normal to a supersonic rarefied air stream total temperature 300 k are described for the mach number range of 1 3 to 5 7 the reynolds number range of 37 to 4 100 and at cylinder wall average temperature levels of 90 k and 210 k study of the results yielded 1 a correlation equation for the stagnation point nusselt number as a function of the reynolds number just after the normal part of the detached bow shock wave and 2 fourier series expressions for the heat transfer coefficient and pressure coefficient distributions in terms of the stagnation point values in comparing these measurements with predictions based on recent analytical studies exceptionally good agreement for the heat transfer coefficient distribution was obtained with lees theory in the mach number range of 3 55 to 5 73 the pressure decreased less rapidly with distance from the stagnation point than predicted by the modified newtonian theory
CRAN	second order theory for unsteady supersonic flow past slender pointed bodies of revolution second order theory for unsteady supersonic flow past slender pointed bodies of revolution an analysis is made of the second order effects of thickness on the unsteady aerodynamic forces on a slender pointed body of revolution in supersonic flow the theory is restricted to harmonic oscillations for small angles of attack the solution is obtained by approximating the nonlinear terms in the second order potential equation by their first order values and solving the resulting inhomogeneous partial differential equation subject to more refined boundary conditions the pressure equation is likewise refined and integrated to give the second order corrections to lift and pitching moment coefficients the analysis can be considered as an extension of the second order slender body theory of lighthill to the case of unsteady flow the results indicate appreciable reductions in unsteady lift and damping moment coefficients when applied to slender cones the present theory is estimated to be reliable provided that is less than 0 7
CRAN	on the response of the laminar boundary layer to small fluctuations of the free stream velocity on the response of the laminar boundary layer to small fluctuations of the free stream velocity the linearized treatment of small time dependent disturbances of a laminar boundary layer initiated by lighthill is extended in several ways in particular the high frequency expansion is continued beyond the leading stokes term several interesting questions of joining occur which are discussed but left unresolved in addition a practical method for obtaining the response to the laminar boundary layer to an impulsive change in velocity is presented the methods are applied to the case in which the basic steady flow belongs to the falkner and skan family of similarity solutions
CRAN	a method of calculating velocity distribution for turbulent boundary layers in adverse pressure distributions a method of calculating velocity distribution for turbulent boundary layers in adverse pressure distributions a new method of calculating the behavior of turbulent boundary layers in adverse pressure distributions is developed which permits direct determination of the velocity profile rather than the gross integral parameters normally used to infer the general character of the boundary layer the method offers the simplicity of algebraic equations coupled with the use of charts rather than the laborious simultaneous solution of coupled differential equations required by existing methods the method also affords for the first time a means of determining the total boundary layer thickness thus allowing calculation of the absolute as well as the nondimensional velocity distribution the velocity profile is considered to be composed of two regions  an inner region which is described by the law of the wall and an outer region which is described by a function depicting the deviation from that law the deviation function involves two parameters which are uniquely dependent upon the skin friction coefficient and a third parameter which for practical purposes can be considered a constant since the entire velocity distribution was found to be almost uniquely dependent upon the local skin friction serious doubt is cast upon the generally accepted history concept which considers the outer region of the boundary layer to be dependent on integrated upstream conditions agreement between experimental velocity distributions and those calculated by the method presented here is generally very good the analysis and calculation procedures which are presented are applicable to two dimensional pseudo two  dimensional and axisymmetric conical flows
CRAN	an extension of the linearized characteristics method for calculating the supersonic flow around elliptic cones an extension of the linearized characteristics method for calculating the supersonic flow around elliptic cones the method of linearized characteristics as applied by ferri to the flow about elliptic cones can be used to determine the surface pressure distribution even when only linear terms are kept in the boundary conditions provided an area rule requirement is satisfied in addition the method can be applied for angles of attack provided the elliptic body geometry is specified in a manner that does not distort the cross section the surface pressure distribution obtained by this modified method is in reasonable agreement with experiment over the range of mach numbers and semidiameter ratios considered experimental results for several conical bodies are presented
CRAN	turbulent heat transfer through a highly cooled partially dissociated boundary layer turbulent heat transfer through a highly cooled partially dissociated boundary layer the problem of heat transfer from high temperature air through a turbulent boundary layer to a cold surface is considered both analytically and experimentally heat transfer data obtained in shock tubes are presented and correlated by a semiempirical theory which includes the effect of atomic diffusion the distinguishing characteristics of turbulent boundary layers with dissociation and large cooling are considered it is shown that the equations governing such flow after certain approximations can be represented in a form similar to the classical equations for a turbulent boundary layer an approximate theory is proposed for turbulent heat transfer for a highly cooled boundary layer on portions of the body where the pressure gradient is negligible in the case of blunted bodies of revolution in high speed flight experimental results obtained on the cylindrical portion of a hemisphere cylinder model are presented for conditions simulating flight speeds to 21 350 ft sec where up to 30 per cent of the molecules are dissociated reynolds numbers of 2 5 x 10 based on local fluid properties external to the boundary layer were achieved the larger values of reynolds number and flight speed were not obtained simultaneously due to structural limitations of the shock tubes however the experiments were conducted in such a way that the important effects of each could be determined in the experiments the mach number external to the boundary layer varied between 1 7 and 2 2 the corresponding mach number for blunted nonslender bodies in flight would have a maximum value between 2 5 and 4 however it is shown that these differences in mach number are not important for such bodies
CRAN	boundary layer transition and heat transfer in shock tubes boundary layer transition and heat transfer in shock tubes an experimental study is made of the wall boundary layer in a shock tube operated over a wide range of shock mach numbers and pressure levels in air including those for which real gas effects exist transition distances are determined and correlated in terms of the transition reynolds number based on a characteristic length for this boundary layer data from independent shock tube studies are also included in this correlation the results indicate a weak dependence of transition reynolds number on shock strength up to moderate values of shock mach number followed by a larger stabilizing tendency comparison of these data with transition data obtained in the same manner in argon indicate that the increased cooling rates are largely responsible for the stabilization a dependence of transition reynolds number on the unit reynolds number is found at the lower shock strengths specifically higher transition reynolds numbers are achieved at larger unit reynolds numbers the phenomenon of transition reversal does not appear within the range of the experiments reported laminar  and turbulent flow heat transfer rates to the walls of the shock tube are determined experimentally the results of the heat transfer measurements substantiate existing theories in both the laminar  and turbulent flow regimes
CRAN	on the thrust hypothesis for the jet flap including jet mixing effects on the thrust hypothesis for the jet flap including jet mixing effects this paper is concerned with the thrust generated by a jet flap it is shown that a linear thrust hypothesis can be obtained provided linearized potential flow is assumed in fact the linearized problem of a jet flap system is found to be the linear combination of a lift problem and a thrust problem the lift problem gives all the lift generated but it is of interest to note that the thrust problem would yield all the thrust developed by the jet flap within the limitation of the linearized theory the mixing of the jet flap with the surrounding fluid is analyzed by the momentum integral method the analysis substantiates stratfords suggestion for obtaining an increase of thrust by causing the jet to mix with the main stream in a region of high suction finally some approximate formulas relating the thrust and the jet angle are derived the drag of the airfoil section and other viscous effects are however not considered
CRAN	minimum wing wave drag with volume constraint minimum wing wave drag with volume constraint a numerical method is developed for calculating the minimum thickness drag for a given wing planform and volume using linearized supersonic flow theory the corresponding optimum volume distribution is also determined the results show that considerable drag reduction is possible by improved volume distribution
CRAN	on supersonic flow past thick airfoils on supersonic flow past thick airfoils the inviscid rotational supersonic flow behind the shock wave attached to the sharp leading edge of an airfoil is studied by a transformation of coordinates which introduces the crocco stream function as an independent variable using expansions in the power series of an iterative process is developed for the determination of pressure distribution along the airfoil surface
CRAN	stable combustion of a high velocity gas in a heated boundary layer stable combustion of a high velocity gas in a heated boundary layer it is generally recognized that stable combustion processes in heated boundary layers may be achieved by either of two conceptual mechanisms in one mechanism it is pictured that the heat transfer to the wall quenches the propagating flame at a certain distance from the surface the equality between the flow velocity and the normal burning velocity at this quenching distance determines the position of the propagating flame in the second mechanism it is conceived that the hot surface provides a continuous source of ignition in much the same manner that the hot recirculation zone of a bluff body flame holder provides continuous ignition to the gas flowing around it in this case it is the characteristic time during which the gas must be heated that determines the position of the flame all experimental work reported to date has been concerned with conditions where the first picture has apparently been applicable in the present paper experiment and analysis are given that show under what conditions the continuous ignition mechanism provides the appropriate model and also how the two models are related to differentiate the two mechanisms an experiment was set up to study flame stabilization in high velocity boundary layers over a wall heated in the form of a step function with a turbulent boundary layer and a wall temperature above 1 700f the characteristic time was found to be a systematic and reproducible variable these observations led to the conclusion that a continuous ignition mechanism governs stabilization in heated turbulent boundary layers a rational explanation is made for the transition from the low speed mechanism known to be applicable in unheated turbulent boundary layers and heated laminar boundary layers to the ignition mechanism applicable in heated turbulent boundary layers as a further verification of the continuous ignition mechanism an apparent ignition energy was found the logarithm of the heat added at the lower stability limit was found to be a linear function of the reciprocal of the limiting wall temperature the activation energy derived from this arrhenius type of relation agreed reasonably well with the estimated value for the fuel used
CRAN	a study of supersonic combustion a study of supersonic combustion steady stable plain and oblique detonation waves were created in a high temperature steady flow supersonic tunnel ignition conditions and properties across the wave were measured the local wave fluid dynamic properties agree well with detonation theory experimental data are presented in detail and compared with other studies and theory experimental behavior of these detonations and their possible utility are discussed
CRAN	supersonic inlet dynamics supersonic inlet dynamics an approximation of the differential equation for compressible duct flow is presented the equation is linear and of the second order the duct transfer function and response characteristics are obtained by applying small perturbation theory to the differential equation the resulting equations describe duct natural frequency as a function of duct areas and volumes and damping ratio as a function of the slope of the steady state mass flow pressure recovery curve the calcualted response agrees to a first approximation with measured response as obtained from tests of a fixed geometry sugar scoop inlet model with hypass for matching airflows testing was done in the 10 x 10 and 8 x 6 ft supersonic tunnels at nasa lewis flight propulsion laboratory further agreement was obtained during flight tests of the f8u 3 airplane
CRAN	theory of supersonic propeller aerodynamics theory of supersonic propeller aerodynamics a supersonic propeller with blades attached to an infinite cylinder as a hub is studied the forward speed may be subsonic but the relative speed at each section is supersonic the lightly loaded blades are represented by a surface distribution of appropriate modified sources in a fashion similar to ordinary supersonic thin wing theory these sources are found by approximating the exact potential for a constant strength compressible source traveling along a helical path the usual relationship between the source strength and boundary condition is found and subsequently the source distribution is given to the appropriate order in terms of the blade geometry tip effects are considered by extending the theory of evvard and krasilshchikova the present investigation however is restricted to those planforms for which no vortex sheet appears off the tip for points in the tip region the potential is obtained through the appropriate distribution of modified sources in the upwash region off the tip by transforming to a curvilinear nonorthogonal coordinate system coincident with the modified mach lines described by the infinities of the potential an integral equation for the required source distribution in the upwash region is derived without having to solve this equation it is shown that the potential for a point in the tip region can be obtained in terms of an integration of known source distributions over the blade surface only the case of a twisted flat plate of particular planform is treated and a sample calculation is made of the pressure distribution at selected radial positions within the noncommunicating portion of the blade as well as over the entire tip region though this analysis is carried out explicitly for the supersonic propeller it could also be extended to calculate various rotary derivatives for highspeed flight vehicles
CRAN	oscillatory aerodynamic coefficients for a unified supersonic hypersonic strip theory oscillatory aerodynamic coefficients for a unified supersonic hypersonic strip theory this investigation presents a derivation of the oscillatory aerodynamic coefficients for wings with supersonic leading edges from the second order nonlinear unsteady supersonic flow theory of van dyke the theory is considered applicable throughout the supersonic hypersonic regime at mach numbers normal to the leading edge and reduced frequencies for which the coefficients are modified for sweep and a finite span correction is suggested to increase the accuracy of strip theory flutter analyses the limiting values of the coefficients in steady flow are also discussed
CRAN	magnetohydrodynamic effects on the formation of couette flow magnetohydrodynamic effects on the formation of couette flow this paper is concerned with the problem of the formation of couette flow  i e the problem of how the velocity profile varies with the time tending asymptotically to that of the steady flow of an electrically conducting viscous fluid in the presence of a magnetic field the governing equations and boundary conditions are established and discussed the cases of both vanishing and nonvanishing mean induced electric field strengths are solved in terms of complimentary error functions as well as some elementary functions it is shown that the solutions are reducible to that of the steady case as the time approaches infinity and to that of the nonmagnetic field as the hartmann number becomes zero some numerical calculations are given the results indicate that in the presence of a magnetic field the flow rate is reduced depending on the magnitude of the hartmann number and that the magnetic field assists the flow to reach its steady condition
CRAN	real gas effects in flow over blunt bodies at hypersonic speeds real gas effects in flow over blunt bodies at hypersonic speeds a hypersonic shock tunnel has been developed to investigate the aerodynamic characteristics of flow over bodies at conditions comparable to those encountered by ballistic missiles and satellites re entering the atmosphere some results for a shock velocity of over 50 000 ft per sec in the shock tube portion of the facility are presented static pressure investigations were made in the nozzle to determine the flow condition and the expansion process the results of the investigation of representative blunt bodies at hypersonic mach numbers and nozzle stagnation temperatures up to approximately 6 000degreek are presented these include body pressure distributions shock wave shapes detachment distances and photographs of the luminous gas region in the shock layer it is seen that the shock detachment distance is smaller at higher stagnation temperatures due to the real gas effects for the hemisphere the pressure distribution was less than that predicted by the modified newtonian theory for all stagnation temperatures for a 50degree cone hemisphere the pressure distribution and the shock detachment distance were appreciably affected by the real gas effects the observed shock wave shape and the approximate boundary layer on a flat plate are compared with the analytical prediction some preliminary results for the detached shock wave produced by a blunt two  dimensional body in a low density flow at a mach number of 19 6 are presented
CRAN	flow about an unsteadily rotating disc flow about an unsteadily rotating disc an analysis is made of the unsteady laminar flow about a rotating disc whose angular velocity may vary with time the deviation of the actual instantaneous state of the flow from the quasi steady state instantaneous steady state is determined from this a simplified criterion is derived to define the conditions under which the flow can be considered as quasi steady for the purposes of shear stress and torque computations since a turbulent flow responds more rapidly than a laminar flow the quasi steady criterion found here should also serve for the turbulent situation
CRAN	a three dimensional linearized analysis of the forces exerted on a rigid wing by a shock wave a three dimensional linearized analysis of the forces exerted on a rigid wing by a shock wave the pressure distribution on a moving flat plate induced by an acoustic shock front striking the edge of the plate obliquely has been found in terms of the two dimensional solution of the authors
CRAN	a study of vortex cancellation a study of vortex cancellation the cancellation of a vortex by means of another concentric vortex of equal strength but opposite spin is investigated when such a cancellation occurs there is a recovery of static pressure the vortices are generated by means of two three dimensional airfoils cantilevered from the duct wall one being situated in the wake of the other the airfoils have opposite effective angles of attack and therefore have trailing vortices of opposite spin as required it is demonstrated experimentally that there exists an optimum angle of attack for the second airfoil which cancels the vortex from the first airfoil and restores uniform flow downstream of the two airfoils a theoretical solution of this optimum angle of attack is presented and it is found to depend upon the angle of attack of the first airfoil and upon the geometrical properties of the wings the pressure recovery accompanying the vortex cancellation is also studied theoretical considerations based on the model of a vortex filament in the center of a circular tube show that a maximum of 62 per cent of the static pressure drop across the first airfoil can be recovered this maximum is imposed irrespective of skin friction and separation losses by the irreversibility associated with establishing a vortex field experimental pressure recoveries of 50 per cent are realized perhaps the primary value of the present study is the opportunity it provides to verify certain of the fundamental concepts of fluid mechanics which are brought into play when the trailing vortex system of a lifting wing is cancelled by a second wing
CRAN	transition in a separated laminar boundary layer transition in a separated laminar boundary layer transition to turbulence was studied in a separated laminar boundary layer on a flat plate 24 in long and thick steps with a height of to were provided at a distance of 4 to transition was observed through a hot wire anemometer the author concludes that transition was always initiated by tollmien schlichting waves two types of transition were observed in one type bursts suddenly appeared in the wavy flow the other type consists of amplification distortion and breaking up of the waves which type of transition occurs depends on the value of the following parameter boundary layer displacement thickness times step height times free stream velocity squared divided by kinematic velocity squared the burst type has been observed for values of this parameter larger than 4 2 x 10 the separated laminar boundary layer becomes unstable and develops waves when the critical reynolds number based on boundary layer displacement thickness at the step location exceeds a value of 350 some conclusions on the development of separation bubbles on air foils are drawn from the present studies
CRAN	sublimation in a hypersonic environment sublimation in a hypersonic environment a priori knowledge of the response of materials subjected to a severe aerothermal environment is essential in the space age the successful design of space and re entry vehicles demands that the fundamental problem of the interaction between a material and dissociated air be properly formulated and solved in this paper the problem of sublimation in a hypersonic environment is considered in this study of hypersonic ablation the pertinent conservation equations are derived and the simultaneous processes of diffusion convection and thermal exchange are analyzed for the vaporization of a refractory material which is subjected to the environmental conditions encountered during hypersonic reentry for simplicity only the forward stagnation point of an axially symmetric body is treated it is shown that the quantity called the effective heat of vaporization which includes all heat absorbing or heat blocking effects is an increasing function of flight speed independent of body size except where nonequilibrium vaporization effects or radiative effects appear
CRAN	wings with minimum drag due to lift in supersonic flow wings with minimum drag due to lift in supersonic flow it has been shown by r t jones that in order to produce minimum drag the given lift must be distributed over the wing surface in such a way that the sum of the downwash induced by this distribution and the downwash induced in reversed flow is constant over the wing surface this combined downwash can be expressed by an integral which contains the load as a function of the spanwise and chordwise coordinate the problem of finding the appropriate load distribution is thus reduced to the problem of finding the solution of a rather cumbersome integral equation the severe spanwise singularity of the kernel function is handled most easily as in corresponding subsonic problems by an approximate integration over interpolation polynomials the chordwise load distribution is represented by a limited series development in legendre polynomials the sigularity of the kernel function along the mach lines through any pivotal point can be avoided by a similar legendre development of the combined induced downwash which is constant the integral equation is thus converted into a system of linear equations for the unknown coefficients of the legendre functions of the load distribution at a limited number of spanwise stations practical calculations are carried out on an electronic computer the solutions yield the optimum load distribution and the local incidence twist camber etc necessary to realize this distribution for many wing plan forms considerable gains over a plane wing appear possible
CRAN	turbulent heat transfer on blunt nosed bodies in two dimensional and general three dimensional hypersonic flow turbulent heat transfer on blunt nosed bodies in two dimensional and general three dimensional hypersonic flow recent results obtained for three dimensional laminar boundary layers are extended to the turbulent case it is shown that in the presence of highly cooled surfaces and of moderate mach numbers of the outer stream the crossflow and the pertaining reynolds stresses in a general three dimensional turbulent boundary layer are negligible even for large transverse pressure gradients a correlation due to mager between two  dimensional compressible and incompressible turbulent boundary layers is extended to the problem in question from a study of the transformation and of its implications a rapid method for the analysis of the boundary layer flow under the subject conditions is established in the absence of general three  dimensional data a comparison with experiments and with the predictions of other known analyses is carried out for several axisymmetric configurations the results of the method presented here exhibit good agreement with the data the range of validity of the cold wall approximation for general three dimensional problems is estimated qualitatively on the basis of recent measurements in laminar flow the argument being that for either zero or favorable streamwise pressure gradients smaller three dimensional effects are to be expected in a turbulent boundary layer as compared to a laminar layer
CRAN	compressible flat plate boundary layer flow with an applied magnetic field compressible flat plate boundary layer flow with an applied magnetic field the laminar boundary layer equations are formulated and solved for a flat plate in high speed compressible air flow where equilibrium dissociation and ionization are assumed and where there is an applied magnetic field having its component normal to the plate proportional to the skin friction and heat transfer characteristics are determined for free stream velocities of up to 17 500 meters sec and magnetic fields of up to about the results show that the skin friction and heat transfer at a given free stream velocity decrease with increasing magnetic field strength and the percentage reduction is constant along the length of the plate they also exhibit the same hysteresis behavior as was first found in the case of magnetoaerodynamic couette flow however for the flat plate the hysteresis effect disappears at a higher mach number furthermore it was found that the reduction in heat transfer with increasing field strength is opposite in behavior from that for couette flow
CRAN	on shearing flow between porous coaxial cylinders on shearing flow between porous coaxial cylinders the flow between concentric porous cylinders in relative axial motion with a pressure gradient is considered the analysis is restricted by the assumption that the velocity distribution is a function of the radial coordinate only so that there is no net injection or withdrawal of fluid at any station this assumption reduces the problem to a soluble system of ordinary differential equations an associated heat transfer problem is also discussed briefly
CRAN	the transition to tubulence in a boundary layer on a blunt cone in supersonic flow the transition to tubulence in a boundary layer on a blunt cone in supersonic flow experiments were made with a series of cones each having an included angle of 15 degrees and having different tip radii sharp to blunt nose the cones were tested in streams undisturbed mach numbers of 3 12 and 3 81 and the position of transition to turbulence was observed with a shadowgraph technique for each mach number the distance to transition distance downstream from the tip of the cone increased with increase in tip radius reached a maximum at a certain tip radius and then decreased with increase in tip radius a study indicates that a reynolds number based on the momentum thickness instead of the length from tip to transition is a more appropriate parameter for correlating the data the research scientist active in this field probably would derive the most benefit from the original paper
CRAN	experiments at hypersonic speeds on circular cones at incidence experiments at hypersonic speeds on circular cones at incidence pressure distribution measurements on five circular cones with total apex angles ranging from 25 to 45 degrees are described the tests covered a range of angles of incidence from 0 to and 8 60 the extent to which various analytical and empirical theories predict the measured pressures is assessed
CRAN	equilibrium real gas performance charts for a shypersonic shock tube wind tunnel employing nitrogen equilibrium real gas performance charts for a shypersonic shock tube wind tunnel employing nitrogen charts are presented covering a wide range of reflected shock wind tunnel operating conditions using nitrogen as the working gas a statistical mechanical model of the gas is assumed which takes account of molecular vibration electronic excitation and dissociation the gas is assumed to be constantly in equilibrium that is the reaction rates are taken to be infinitely fast the equations of motion are solved with the aid of a digital computer previously reported results for the state of the shock processed gas in the shock tube being used
CRAN	progress report on an experiment on the effect of surface flexibility on the stability of laminar flow progress report on an experiment on the effect of surface flexibility on the stability of laminar flow this paper describes the flexible surfaces whose properties have been examined and which have been tested on an aerofoil in a wind tunnel the experiment has been rather inconclusive as no drag reductions have been found in turbulent flow whilst the only rearward movements of transition occurred in conditions where the alteration has been inhibited by the onset of laminar separation the limitations of the experiment are discussed carefully in order to clarify the next steps which are to be taken with more flexible surfaces with less damping
CRAN	analysis of the fluid mechanics of secondary injection for thrust vector control analysis of the fluid mechanics of secondary injection for thrust vector control an analysis is made of the interaction of an injected gas or liquid with a supersonic stream and the force induced on an adjacent wall is predicted the study deals only with the freestream injectant interaction the modifications to the flow introduced by the boundary layer are not considered in the case of liquids it is shown that the momentum deficit of the injectant relative to the freestream may play a larger part in producing the side force than the volume generation by vaporization and reaction the analytical results are compared with those obtained from experiments in a wind tunnel and in nozzles
CRAN	numerical technique to lifting surface theory for calculation of unsteady aerodynamic forces due to continuous sinusoidal gusts on several wing planforms at sobsonic speeds numerical technique to lifting surface theory for calculation of unsteady aerodynamic forces due to continuous sinusoidal gusts on several wing planforms at sobsonic speeds a numerical lifting surface method has been used to calculate direct gust forces and moments on wings of several planforms the gust velocities are continuous and vary sinusoidally in the stream direction and are also uniform across the wing span the procedure has the advantage of rapid machine calculation and includes the effects of wing planform nonsteady subsonic flow and induced flow effects the method provides for calculation of gust forces on a basis consistent with that for the calculation of forces due to motion and deformation the results include the in phase and quadrature components of the following quantities a spanwise distribution of section lift coefficient b total lift coefficient and c total pitching moment coefficient in addition generalized gust forces on approximate fundamental cantilever bending modes parabolic are also included results have been obtained for 60 and 75 delta wings ratio 11 60 and an unswept wing of aspect ratio 6 00 conditions for which calculations were made include two mach numbers reduced frequency range of 0 to 1 0 the direct gust forces and moments are in forms suitable to be inserted in equations of motion used in the calculation of the dynamic responses of flexible lifting vehicles to random turbulence and to be compared with results from other methods
CRAN	measured and calculated subsonic and transonic flutter characteristics of a 45 sweptback wing planform in air and in freon 12 in the langley transonic dynamics tunnel measured and calculated subsonic and transonic flutter characteristics of a 45 sweptback wing planform in air and in freon 12 in the langley transonic dynamics tunnel in order to investigate the reliability of flutter data measured in the langley transonic dynamics tunnel an experimental and theoretical subsonic and transonic flutter study has been conducted in air and in freon 12 in this facility the wing planform employed had an aspect ratio of 4 0 a taper ratio of 0 6 and 45 of quarter chord sweepback a sting mounted full span model was tested in addition to three sizes of wall mounted semispan models a wide range of mass ratio was covered by the tests in air and by flutter calculations made by the modified strip analysis method of naca research memorandum l57l10 a limited amount of data was obtained in freon 12 results of the tests in air and in freon 12 are in good agreement with the flutter calculations at all mach numbers the test data compare favorably with previously published transonic flutter data for the same wing planform the results indicate that flutter characteristics obtained in freon 12 may be interpreted directly as equivalent flutter data in air at the same mass ratio and mach number
CRAN	atmosphere entries with spacecraft lift drag ratios modulated to limit decelerations atmosphere entries with spacecraft lift drag ratios modulated to limit decelerations an analysis has been made of atmosphere entries for which the spacecraft lift drag ratios were modulated to limit the maximum deceleration the parts of the drag polars used during modulation were from maximum lift coefficient to minimum drag coefficient five drag polars of different shapes were assumed for the spacecraft the entries covered wide ranges of initial velocity initial flight path angle initial and maximum lift drag ratio two dimensional trajectory calculations were made for a nonrotating spherical earth with an exponential atmosphere the results of the analysis indicate for four of the five drag polars that relative to the maximum deceleration of an unmodulated entry at maximum lift drag ratio the greatest reduction in maximum deceleration obtainable by modulation depends upon a single parameter this parameter is the ratio of the value of the aerodynamic resultant force coefficient at minimum drag coefficient to the value at maximum lift coefficient thus the reduction in maximum deceleration is independent of initial velocity initial flight path angle initial maximum lift drag ratio and the shape of the drag polar for the fifth drag polar the reduction in maximum deceleration was found to depend upon the maximum lift drag ratio also relative to the depth of a given deceleration limited corridor the greatest increase in corridor depth obtainable by modulation for four of the five drag polars depends upon the same ratio of aerodynamic resultant force coefficients the fractional increase in corridor depth can be expressed as an empirically determined analytical function of this ratio
CRAN	effect of jet pluming on the static stability of cone cylinder flare configurations at a mach number of 9 65 effect of jet pluming on the static stability of cone cylinder flare configurations at a mach number of 9 65 the effects of jet pluming on normal force and pitching moment of have been measured at a free stream mach number of 9 65 with reynolds numbers based on model length of 500 000 to 600 000 geometric variables included nose bluntness flare half angle and nozzle geometry and exit displacement two test nozzles with design mach numbers of 3 74 and 4 60 were operated with compressed air to simulate the initial jet boundary shape of a particular solid propellant rocket motor operating between altitudes of 165 000 and 215 000 feet the ratio of the jet pressure to free stream static pressure varied from a jet off condition to approximately 1 300 for the nozzle with design mach number of 3 74 and from a jet off condition to approximately 280 for the nozzle with design mach number of 4 60 the angle of attack range was from 0 to approximately 6 the results indicate that as the jet pressure ratio was increased the size of the jet plume increased and as a result the model static stability was decreased increasing the angle of attack resulted in a reduction in static instability during the jet on condition increasing nose bluntness resulted in a more forward movement of the center of pressure when jet plume interference was not present and a rearward movement in the center of pressure when jet interference was present increasing the nozzle area expansion ratio and displacing the nozzle exit downstream of the flare base resulted in a more rearward location of the center of pressure
CRAN	design of stiffened cylinders in axial compression design of stiffened cylinders in axial compression the problem of optimum design of axially compressed cylinders stiffened by rings and stringers is discussed particular attention is devoted to configurations suitable for large launch vehicles consideration is given to the analytical techniques for determining strength as well as the procedures for optimization
CRAN	non linear shallow shell analysis by the matrix force method non linear shallow shell analysis by the matrix force method the matrix force method of redundant structure analysis is currently being extended by various users to cover a number of non linear problems one of these is the non linear analysis of heated cambered wings such as might be used in advanced flight vehicles in this case the approach used by the present authors is equally applicable to shallow shells the formulation of the strain displacement and equilibrium relations being a finite element equivalent to that used by marguerre the solution is obtained by a combined iteration and step by step procedure utilizing a tangent flexibility matrix divergence in the calculations indicates that the range of stable configurations has been exceeded cambered plates subjected to several loadings are given as examples for one an exact solution is available for comparison it is believed that the basic concepts involved in this shallow shell analysis can be extended to apply to other more general shell instability problems and that useful solutions to the latter are probably within the capability of present day digital computers
CRAN	recent advances in nonequilibrium dissociating gasdynamics recent advances in nonequilibrium dissociating gasdynamics the purpose of this paper is to review some recent advances in the study of gasdynamic problems including effects of chemical reactions to provide a background for the study the general concepts shall be outlined briefly the discussions of the recent developments are restricted to inviscid flow problems only neglecting viscosity heat conduction and diffusion particular attention is directed to recent advances in analyses of nonequilibrium dissociating gas flows in the hypersonic flight regime high stagnation enthalpies sufficient to cause dissociation are realized when the time to reach equilibrium is comparable with the time it takes for a fluid particle to pass through the flow then there exist regions of the flow field where nonequilibrium states are encountered a brief survey of both the linear and the nonlinear methods of treatment of these nonequilibrium flows including some new developments that have not appeared elsewhere will be presented
CRAN	non equilibrium expansions of air with coupled chemical reactions non equilibrium expansions of air with coupled chemical reactions analysis and solutions of the streamtube gas dynamics involving coupled chemical rate equations are carried out results are presented for airflows along the surface of blunt bodies and through hypersonic nozzles speeds and altitudes corresponding to re entry were selected to obtain initial conditions for the external flow calculations conditions appropriate to hypersonic tunnel testing were chosen for the nozzle flow calculations composition histories are shown for a kinetic mechanism including 6 species and 14 reactions gas dynamic effects of nonequilibrium processes qualitatively resemble those reported earlier however the freezing process is complicated by the coupling of the nitric oxide shuffle reactions with the dissociation recombination reactions in many cases of hypersonic nozzle flows where the energy in nitrogen dissociation is significant the fast shuffle reactions prevent nitrogen atom freezing which would otherwise occur if three body recombination were the only process operating nitric oxide concentrations undershoot the equilibrium values if the ratio of nitric oxide to oxygen molecule concentrations exceeds unity in the freezing region this depletion of nitric oxide leads to nitrogen atom freezing
CRAN	ionization nonequilibrium in expanding flows ionization nonequilibrium in expanding flows approximate methods are developed for solving the electron ion kinetic equations in expanding quasi one dimensional airflows results are obtained for inviscid nozzle flows at conditions appropriate to shock tunnel testing and are compared with exact numerical solutions effects on rf transmission and d c conductivity are examined since two body deionization never fully freezes in the flows considered here the assumption of sudden freezing gives an upper bound on the residual ionization at large area ratios the use of an asymptotic form of solution with the freezing criterion provides an improved estimate for such cases ionization nonequilibrium is also considered for the plasma sheath associated with blunt hypersonic bodies flying at high altitudes the influence of atomic ions is examined for typical re entry conditions
CRAN	theory of radiation from luminous shock waves in nitrogen theory of radiation from luminous shock waves in nitrogen the physical properties behind a normal shock in nitrogen are calculated as a function of time these include the variation of temperature composition ionization and the intensity of radiation from the n first negative band system this calculation incorporates a rate equation for the dissociation of nitrogen the conservation laws an equation describing vibrational relaxation and a method of coupling the vibrational relaxation with the dissociation rate the n radiation is computed assuming excitation of the radiating state by collision with vibrationally excited nitrogen molecules a particular case is considered for which experimental data are available and regions sensitive to particular rates are indicated
CRAN	hypersonic viscous shock layer hypersonic viscous shock layer a decade ago tsien 1 as well as others and more recently adams and probstein 2 have attempted to define the different regimes of gaseous interactions during high altitude flight in this note some results are presented which are pertinent to the flight of hypersonic lifting vehicles composed of axially symmetric and two dimensional elements sec fig 1
CRAN	some effects of bluntness on boundary layer transition and heat transfer at supersonic speeds some effects of bluntness on boundary layer transition and heat transfer at supersonic speeds large downstream movements of transition observed when the leading edge of a hollow cylinder or a flat plate is slightly blunted are explained in terms of the reduction in reynolds number at the outer edge of the boundary layer due to the detached shock wave the magnitude of this reduction is computed for cones and wedges for mach numbers to 20 concurrent changes in outer edge mach number and temperature occur in the direction that would increase the stability of the laminar boundary layer the hypothesis is made that transition reynolds number is substantially unchanged when a sharp leading edge or tip is blunted this hypothesis leads to the conclusion that the downstream movement of transition is inversely proportional to the ratio of surface reynolds number with blunted tip or leading edge to surface reynolds number with sharp tip or leading edge this conclusion is in good agreement with the hollow cylinder result at mach 3 1 application of this hypothesis to other mach numbers yields the result that blunting the tip of a slender cone or the leading edge of a thin wedge should produce downstream movements of transition by factors ranging from 2 at mach 3 0 to 30 at mach the possible reduction in over all heat transfer rate and friction drag for aircraft flying at high supersonic speeds mach number profiles near the surfaces of blunted cones and wedges are computed for an assumed shape of the detached shock wave at flight mach numbers to 20 the dissipation and stability of these profiles are discussed and a method is described for estimating the amount of blunting required to produce the maximum possible downstream movement of transition
CRAN	compressible boundary layers on bodies of revolution compressible boundary layers on bodies of revolution in a former paper 1 it has been shown that the behaviour of the laminar boundary layer on a body of revolution can be described mathematically by the same equations which are also applied to the processes in the laminar boundary layer in the two dimensional flow along a body contour the form of which is determined by the shape of the body of revolution a simple relation exists between the two dimensional boundary layers and the axially symmetrical ones the flow had been assumed to be incompressible in this report it shall be shown that this relation is still valid when the compressibility is taken into consideration the distribution of velocity as well as that of temperature in the laminar boundary layer of a body of revolution can be calculated by solving the corresponding problem for the two dimensional flow around a suitable contour the method is made clear by the example of the supersonic flow towards a cone tip this example has already been treated by another method by hantzsche and wendt 2
CRAN	the development of the boundary layer in supersonic shear flow the development of the boundary layer in supersonic shear flow the development of the boundary layer in a velocity shear layer is discussed for two dimensional flow and for axisymmetric flow of both compressible and incompressible fluids it is shown that the solutions obtained by li and glauert for the two dimensional flow of an incompressible fluid are applicable in the more general case after suitable transformations of coordinates have been made new definitions are shown to be necessary and are given for the displacement and momentum thicknesses of such a boundary layer reynolds numbers based on these thicknesses are given and it is shown that any phenomenon which occurs at a constant value of such a reynolds number will occur at a point which as the length scale of the flow increases first moves down stream and then moves slightly upstream this is shown to be in qualitative agreement with experimental results on a blunt cone in a supersonic flow a quantitative comparison of the theoretical and experimental values of displacement and momentum thicknesses is attempted and no disagreement is obvious unfortunately the accuracy of the experiments so far available is insufficient to give positive confirmation of the theory of this note
CRAN	air pressure on a cone moving at high speeds air pressure on a cone moving at high speeds the cone is considered to be moving at a velocity higher than that of sound so that there is in front of it a shock wave moving with the same speed as the cone itself in the first part of the paper the case is investigated mathematically where the flow is irrotational and the pressure velocity and density of the air stream are each constant over the surfaces of cones coaxial with the moving solid cone the complete solution is obtained in numerical form for cones of semi vertical angle of the paper the results are compared with experiment both in respect of pressure distribution as measured in a wind tunnel and also for the 30 cone by comparison with photographs of bullets in flight in the latter case the theory should only be applicable if the speed is 1 46 or more times the velocity of sound and it is in fact found in the photographs that the nature of the wave alters at about this velocity the exact solution found is compared with an approximation given recently by v karman and moore this should be valid for thin spindle shaped bodies and does in fact agree well in the case of the cone of 10 semi vertical angle but diverges increasingly from the truth as the angle is increased
CRAN	newtonian flow over a surface newtonian flow over a surface a general method is presented for the study of a three dimensional hypersonic flow about a body of arbitrary shape when the manner of constructing a double asymptotic development in and is shown formulae are given which enable the first three terms of this development to be obtained while neglecting the theory is then applied to the case of a body of circular cone shape the pressure is given as a triple development in accordance with the preceding parameters and the angle of attack this development neglects a ferris vortical layer is brought into evidence a second application is devoted to calculation of the total forces acting upon bodies of revolution at angles of incidence while neglecting general formulae are established for the coefficients of axial force normal force and moments the formulae are developed according to the powers of incidence the first terms of each formula being of very simple form
CRAN	a proposed programme of wind tunnel tests at hypersonic speeds to investigate the lifting properties of geometrically slender shapes a proposed programme of wind tunnel tests at hypersonic speeds to investigate the lifting properties of geometrically slender shapes a programme of tests at hypersonic speeds on slender bodies is described which has the aim of investigating how lift is generated and the compromises that may be enforced by aerodynamic heating the programme is based on models of simple geometric shape from which lifting configurations will later be built up
CRAN	experiments on circular cones at yaw in supersonic flow experiments on circular cones at yaw in supersonic flow pressure measurements made in the fort halstead supersonic tunnel on two circular cones of semiapex angles 15 and coefficients are compared with corresponding values calculated by theoretical methods and the relative merits of these methods are then discussed
CRAN	laminar heat transfer and pressure measurements at a mach number of 6 on sharp and blunt 15 half angle cones at angles of attack up to 90 laminar heat transfer and pressure measurements at a mach number of 6 on sharp and blunt 15 half angle cones at angles of attack up to 90 two circular conical configurations having 15 half angles were tested in laminar boundary layer at a mach number of 6 and angles of attack up to 90 one cone had a sharp nose and a fineness ratio of blunted nose with a bluntness ratio of 0 1428 and a fineness ratio of 1 66 pressure measurements and schlieren pictures of the flow showed that near conical flow existed up to an angle of attack of approximately near the base and the bow shock wave was considerably curved comparison of the results with simply applied theories showed that on the stagnation line pressures may be predicted by newtonian theory and heat transfer by local yawed cylinder theory based on the yaw angle of the windward generator and the local radius of the cone base effects increased the heat transfer in a region extending forward approximately circumferential pressure distributions were higher than the corresponding newtonian distribution and a better prediction was obtained by modifying the theory to match the pressure at 90 from the windward generator to that on the surface of the cone at an angle of attack of 0 circumferential heat transfer distributions were predicted satisfactorily up to about 60 from the stagnation line by using lees heat flux distribution based on the newtonian pressure the effects of nose bluntness at large angles of attack were very small in the region beyond two nose radii from the point of tangency
CRAN	a guide to the use of the m i t cone tables a guide to the use of the m i t cone tables the second and third volumes of the m i t cone tables have been found to be unsatisfactory in two respects they have been criticized because of their inconvenient tabulation and because the theory on which they are based is inadequate near the cone surface the former is climinated by means of a coordinate transformation empirical evidence is presented to show that the latter may be ignored in practice the exact nature of certain numerical errors in the table is also pointed out
CRAN	hypersonic flows past a yawed circular cone and other pointed bodies hypersonic flows past a yawed circular cone and other pointed bodies a detailed treatment of inviscid hypersonic flow past a circular cone is given for small and moderate yaw angles within the framework of shock layer theory the basic problem of non uniform validity associated with the singularity of the entropy field is examined and a valid first order solution is obtained which provides an explicit description of a thin vortical layer at the inner edge of the shock layer analytic formulas for pressure and circumferential velocity are given consistent to the second order approximation including the non linear yaw effect the study of the entropy field which is not restricted to the hypersonic case also provides corrections to previous work on the yawed cone and confirms the validity of the linear yaw effect on pressure field in the stone theory a related investigation of three dimensional flow fields is presented with special reference to the flow structure near the surface of a pointed but otherwise arbitrary body the inviscid streamline pattern on the surface is given by the geodesics originting from the pointed nose as a leading approximation of shock layer theory associated with this streamline pattern is a vortical sublayer which exists generally at small as well as at large angle of attack at the base of the sublayer enthalpy and flow speed remain essentially uniform
CRAN	survey of inviscid hypersonic flow theory for geometrically slender shapes survey of inviscid hypersonic flow theory for geometrically slender shapes a survey is made of existing theories for the calculation of pressure distributions on slender bodies at hypersonic speeds no account is taken of boundary layer displacement effects which are expected to become important above a mach number of about 10 for a slender body first the breakdown of linearised supersonic theory is demonstrated as mach number increases above about 5 and this is followed by a derivation of the hypersonic similarity rule this section includes a description of the piston analogy next a physical interpretation of hypersonic flow is outlined and a simple derivation of the modified newtonian pressure formula is given the equations of flow through an oblique shock wave are simplified by assuming a strong shock and various results are thereby derived these include the tangent wedge and tangent cone formulae this is followed by a description of the newtonian approximation for slender bodies including the effect of centrifugal forces and the connection with newtonian flow theory is emphasized for the shock expansion method is described in some detail for both two and three dimensional bodies and finally some remarks are made about the available data sheets and tables for estimating pressures on cones and ogive cylinders in yaw the note does not claim to be original even in presentation the aim has been to prepare a reasonably complete survey of available theory for hypersonic flow over slender bodies excluding viscous and explicit real gas effects this will provide the background for further work in which experimental data will be analysed and in conjunction with which it is hoped to produce accurate design methods for estimating pressures and forces on shapes intended for sustained flight at hypersonic speeds
CRAN	some simple solutions to the problem of predicting boundary layer self induced pressures some simple solutions to the problem of predicting boundary layer self induced pressures simplified theoretical approaches are shown based on hypersonic similarity boundary layer theory which allow reasonably accurate estimates to be made of the surface pressures on plates on which viscous effects are important the consideration of viscous effects includes the cases where curved surfaces stream pressure gradients and leading edge bluntness are important factors
CRAN	tabulated solutions of the equilibrium gas properties behind the incidents and reflected normal shock wave in a shock tube tabulated solutions of the equilibrium gas properties behind the incidents and reflected normal shock wave in a shock tube tabulated solutions are presented for the equilibrium gas properties behind the incident and reflected normal shock waves in the shock tube for nitrogen and oxygen they cover the range of shock wave mach numbers up to 12 at intervals of undisturbed gas pressure between 1 and the thermodynamic model of the gas used in the calculations is described in some detail as is the method of solving the equations the limitations of the assumption of thermodynamic equilibrium are discussed with regard to shock tube applications and the estimated accuracy of the tables is indicated
CRAN	on the flow in a reflected shock tunnel on the flow in a reflected shock tunnel the performance of a shock tunnel operated by the reflected shock technique is examined theoretically neglecting viscous effects and high temperature real gas effects particular attention is given to disturbances to the flow at the nozzle entry caused by waves reflected from the contact surface when the operating conditions depart from those for that the first disturbance reflected from the contact surface is weak enough to be tolerated only within a small range of primary shock mach number m e g 5 7 m 6 3 if the pressure at entry to the nozzle is to remain constant to 10 per cent within this range running times much longer than those obtained in straight through shock tunnels are predicted the limitation usually being imposed by the arrival of the expansion wave originating at the diaphragm outside this range of mach number the uniform flow duration between the arrival at the nozzle entry of the primary shock and the first disturbance reflected from the contact surface is shown to be approximately equal to the time between the arrival of the primary shock and the contact surface in a straight through shock tunnel at first sight it appears therefore that the advantages of reflected shock operation are confined to a very narrow range of shock mach number unless a heated driver gas is used in order to vary the mach number for further analysis suggests however that subsequent disturbances in the multiple wave reflection process between the contact surface and the end of the tube are relatively weak over a useful range of shock mach number thus if the flow after the arrival of the early reflected disturbances is used for test purposes long running times seem possible in theory without severe restrictions to the shock mach number experiments have been made in a shock tube and a shock tunnel to provide data for comparisons with the results of the simple theory if allowance is made for viscous effects on the motion of the contact surface fair agreement is found for the disturbances reflected and transmitted by the contact surface and for the arrival of the expansion wave reflection process increases when the shock mach number is raised substantially above the tailored value and a limit to the usable flow duration may result a striking feature of the results is a fall of pressure at the end of the tube immediately after reflection of the primary shock this is attributed to attenuation of the reflected shock resulting from its interaction with the boundary layer on the wall of the tube further research is required to check this explanation and to investigate the effects of reynolds number and of the cross sectional shape and size of the tube the effects of the tail and reflected head of the expansion wave originating at the main diaphragm are discussed it is shown that the arrival of the reflected head at the nozzle entry may impose a severe limitation to the duration of uniform conditions at low shock mach number and that the arrival of the tail may limit the flow duration at high shock mach number unless means can be devised to suppress the expansion wave it is demonstrated that it is desirable to have alternative diaphragm positions in a tube required to operate over a range of shock mach number it is concluded that running times of order 10 milliseconds at a shock mach number of 4 falling to perhaps 1 millisecond at a shock mach number of 8 seem possible in a shock tunnel of reasonable size by using reflected shock operation with unheated hydrogen driving air because of the simplifying assumptions of the theoretical investigations and the deficiencies of the apparatus used for the experiments the present investigation must however be regarded as preliminary in character further research is required to check and extend the findings and topics particularly requiring investigation are listed in the paper
CRAN	production of high temperature gases in shock tubes production of high temperature gases in shock tubes this paper is intended to set forth aerodynamic and thermodynamic calculations which are useful in the production of strong shock waves the experimental production of strong shock waves is discussed comparison of the experimental shock strengths with the theoretical calcualtions is made and finally some preliminary results of shock tube studies in high temperature gases up to 18 000k are briefly surveyed
CRAN	performance estimates for the rae 6in high pressure shock tube performance estimates for the rae 6in high pressure shock tube estimates are made of the performance of the rae 6 high pressure shock tube with various driver gases over a range of pressure ratios giving shock mach numbers from 6 to 22 the calculations are based on a simplified model of shock tube flow in which the working fluid argon free air is assumed to be always in chemical equilibrium and the driver gas either hydrogen or the products of combustion of a hydrogen oxygen mixture is assumed to behave as an ideal gas with constant specifiic heats the results are presented in graphical form and comprise charts normal shock waves in argon free air shock wave mach number and diaphragm pressure ratio under various initial conditions and of the shock induced flows both in the uniform sectioned shock tube and when expanded in a divergent nozzle
CRAN	temperature measurements of shock waves by spectrum line reversal ii a double beam method temperature measurements of shock waves by spectrum line reversal ii a double beam method the sodium line reversal method as previously described using a photomultiplier and oscillograph has been modified two light beams are now employed and interference filters are used in front of the photomultipliers instead of a spectrograph in one beam the background source is viewed directly through the shock tube and in the other beam the background source is viewed through the shock tube by a mirror system with a neutral filter interposed to reduce its effective brightness temperature with a suitably chosen temperature for the background one oscillograph trace indicates absorption and the other indicates emission of the sodium lines it is thus possible from the records of a single shock to determine the temperature history behind the shock wave to about 20degreec nitrogen and oxygen again show relaxation effects near the front temperatures in argon tend to come low owing to radiative disequilibrium excitation processes in argon are discussed with this system it is possible to determine temperatures rather higher than that of the background source some work has also been done with a single beam method using a carbon arc as background and following reversal of the indium blue line temperatures up to 3600degreek have been measured in shocks through nitrogen but the time resolution is not so good
CRAN	shock tube testing time shock tube testing time in a theoretical investigation of attenuation effects of the shock wave the conservation of mass equation led to an explanation of the difference between the ideal theoretical test time and the experimentally obtained time a numerical example is given
CRAN	stagnation temperature measurements in a hypersonic gun tunnel using the sodium line reversal method stagnation temperature measurements in a hypersonic gun tunnel using the sodium line reversal method the sodium line reversal s l r method has recently been used to measure transient temperatures in the 1400degreek to 3000degreek range for example ref 6 reports measurements of gun flash temperatures in the gun tunnel stagnation temperatures in the above range can be generated flow between a blunt body and its bow shock wave the gas temperature in this zone is close to the stagnation value
CRAN	real gas effects in flow over blunt bodies at hypersonic speeds real gas effects in flow over blunt bodies at hypersonic speeds a hypersonic shock tunnel has been developed to investigate the aerodynamic characteristics of flow over bodies at conditions comparable to those encountered by ballistic missiles and satellites re entering the atmosphere some results for a shock velocity of over 50 000 ft sec in the shock tube portion of the facility are presented static pressure investigations were made in the nozzle for different stagnation conditions in order to determine the flow condition and the expansion process the results of the investigation on representative blunt bodies at hypersonic mach numbers and nozzle stagnation temperatures up to approximately 6000degreek are presented these include body pressure distributions shock wave shapes detachment distances and photographs of the luminous gas region in the shock layer it is seen that the shock detachment distance is smaller at higher stagnation temperatures owing to the real gas effects for the hemisphere the pressure distribution was less than that predicted by the modified newtonian theory for all stagnation temperatures for a 50degree cone hemisphere the pressure distribution and the shock wave detachment distance were appreciably affected by the real gas effects the experimentally obtained shock wave shape and the approximate boundary layer on a flat plate are correlated with the analytical prediction some preliminary results for the detached shock wave produced by a blunt two dimensional body in a low density flow at a mach number of 19 6 are presented
CRAN	divergence of plate airfoils of low aspect ratio at supersonic speeds divergence of plate airfoils of low aspect ratio at supersonic speeds in part 1 as a first approach to a theoretical investigation of low aspect ratio rectangular plate wings of constant thickness the two assumptions are made that a the spanwise form of the structural distortion is known leaving the chordwise distortion arbitrary and b the aerodynamic forces are approximations of the supersonic linearized theory the form of the chordwise distortion is then deduced from the differential equation representing the state of neutral equilibrium for small displacements at the critical divergence speed secondly this problem is investigated using measured structural flexibility coefficients together with theoretical aerodynamic coefficients thirdly the usual series solution based on the rayleigh ritz approach is discussed using the same assumptions as in the first method all the results of these methods are consistent and indicate that the transonic regime at m 1 is the most critical for divergence in part 2 it is established that sweeping the leading edge of a plate airfoil of constant thickness increases its stability for angles of sweep less than 30 the critical conditions occur when the leading edge is sonic but for angles greater than 30 the critical conditions occur when m 1
CRAN	effects of a flexible boundary on hydrodynamic stability effects of a flexible boundary on hydrodynamic stability purpose of paper is to examine theoretically the use of coatings of elastic materials to prevent transition from laminar to turbulent flow theory is extension to flexible boundary of the small disturbance tollmien schlichting stability theory and makes use of tietjens function and other functions that occur in solution of orr sommerfeld equation it is shown how solutions for flexible wall can be obtained from solutions for rigid boundary outline and discussion is given first for tollmien schlichting stability theory for rigid wall then for theory for flexible boundary theory is given both for a nondissipative and a dissipative flexible boundary behavior of flexible medium itself is also examined practical requirements are discussed for example a conclusion is that to avoid tollmien schlichting instability the wave velocity of surface waves in absence of flow should coincide with tollmien schlichting wave velocity at wavelength of most dangerous tollmien schlichting waves moreover damping should be large enough to prevent surface waves from developing but not so large that tollmien schlichting waves are permissable author states that a boundary that is both soft and light one whose elastic constants are of same order as the dynamic pressure of the flow may be practical for use at high speeds this surface should have a small damping to avoid tollmien schlichting type of instability and a large enough wave speed without flow to avoid surface wave instability although paper is somewhat sketchy in places it gives comprehensive coverage of stability of laminar flow over a flexible wall
CRAN	qualitiative solutions of the stability equation for a boundary layer in contact with various forms of flexible surface qualitiative solutions of the stability equation for a boundary layer in contact with various forms of flexible surface an appropriate form of the boundary layer stability equation is developed for the condition where the fluid is in contact with an isotropic and homogeneous elastic medium and various approximate analytical solutions obtained for certain types of surface so as to reveal at least qualitatively the origin and characteristics of neutral oscillations in the worked solutions the elastic medium is treated as nondissipative and the interior boundary is supposed either fixed or free of stress or exposed to fluid the boundary layer also is treated as that over a flat plate in an incompressible fluid the results obtained show that the presence of such a resiliant surface introduces the possibility of a number of other modes of oscillation schlichting waves most of these modes have speeds of propagation determined largely by the properties of the elastic material and their presence may well be effectively a matter of non viscous flow stability  dash a subject not treated here the tollmien schlichting mode has its minimum reynolds number increased by the presence of the surface but if the interior boundary is free there may be an upper limit as well indeed a sufficiently thin free surface or one of low rigidity apparently eliminates neutral oscillations of this mode altogether only at the expense however of the introduction of a mode of flexural waves
CRAN	an investigation of the use of an auxiliary slot to re establish laminar flow on low drag aerofoils an investigation of the use of an auxiliary slot to re establish laminar flow on low drag aerofoils the use of an auxiliary slot on a laminar flow aerofoil has been investigated to check whether laminar flow can be re established by suction at the rear of the region of deposited dirt flies etc results indicate that in the absence of unfavourable pressure gradients it is possible to re establish a laminar boundary layer by removing a little more than the whole turbulent layer reaching the slot and preliminary estimates suggest that with efficient ducting it should be possible to achieve a reduction in overall effective drag coefficient by this means
CRAN	the effect on transition of isolated surface excrescences in the boundary layer the effect on transition of isolated surface excrescences in the boundary layer the effect of isolated surface excrescences in a laminar boundary layer in producing disturbances which may lead to turbulent flow has been examined experimentally by several methods photographs of some of the flow patterns visualised by smoke and china clay techniques are given the critical heights of pimple which just give rise to spreading wedges of turbulent flow have been measured on a flat plate and on two aerofoils at several angles of incidence the results are analysed and are presented in a form which enables approximate estimates to be made of the protuberances permissible on laminar flow surfaces at full scale flight reynolds numbers the estimates suggest that at an altitude of 30 000 ft the critical pimple height is 0 004 in for a speed of 350 m p h whilst 0 002 in may be permissible at all subsonic speeds at sea level however the tolerances are approximately halved
CRAN	experiments on the use of suction through perforated strips for maintaining laminar flow transition and drag measurements experiments on the use of suction through perforated strips for maintaining laminar flow transition and drag measurements wind tunnel tests are described in which suction is applied at perforated strips as an alternative to porous strips or slots in order to maintain a laminar boundary layer a test was first carried out on a single row of perforations on a cambered plate as a preliminary to the main tests which were performed on strips of multiple rows of perforations drilled through the surface of a low drag type aerofoil 13 per cent thick and of 5 ft chord up to a wind speed of 180 ft sec it has been ascertained that suction may be safely applied to extend laminar flow provided the ratio of hole diameter to boundary layer displacement thickness is less than 2 the ratio of hole pitch to diameter is less than 3 and there are at least three rows of holes in the strip with less than three rows the criteria are much more restrictive it is possible to extend laminar flow by suction through perforations whose diameters and pitches exceed these values slightly but only with the risk that excessive suction quantities will produce wedges of turbulent boundary layer originating at the holes a uniform distribution of suction through the holes was necessary this was successfully obtained by two methods the use of cells and throttle holes and with tapered holes in particular tests were carried out on some panels supplied by handley page ltd in which the cells and tapered holes had been constructed by commercial methods and the suction distribution proved satisfactory the resistance of some of the cellular arrangements was measured it was found that when the suction quantities were the minimum required to maintain laminar flow the additional losses in total head of the sucked air due to the resistance of the throttle holes could be made small compared with the loss in total head of the sucked boundary layer
CRAN	interaction of secondary injectants and rocket exhaust for thrust vector control interaction of secondary injectants and rocket exhaust for thrust vector control tests were conducted with 1300  to 1500 lb thrust solid rocket motors in order to investigate the side force generation mechanisms associated with the injection of a secondary fluid into the expansion cone of a solid propellant rocket nozzle for thrust vector control the nozzles were 15 conicals with a nominal expansion ratio of all firings were conducted in zero flow ejectors freon 12 water and gascous nitrogen were used as the injectant nozzle wall pressure profiles side thrust and the nozzle wall shock interface were recorded the general character of the pressure disturbance was defined the major portion of the side force was generated by the pressure disturbance downstream of the injector the axial thrust augmentation generated by the injectant was calculated the effects of nozzle expansion ratio and injector location on the side force were clearly illustrated
CRAN	on the propagation and structure of the blast wave on the propagation and structure of the blast wave concerning blast waves with front surfaces of plane cylindrical and spherical shape the propagation velocity u and the distribution of hydrodynamical quantities are discussed the solutions are constructed in the form of power series in c u where c is the sound velocity of undisturbed fluid especially r the distance of shock front from the charge is represented as where r is the characteristic length related to the energy of explosion j and are constants and a 0 1 2 correspond to plane cylindrical and spherical case respectively in this paper the first approximations for a 0 1 are discussed the case a 2 has been discussed by g i taylor the solution is obtained numerically for the case of the adiabatic index the approximate solution is also considered using these solutions is found to be the second approximation will appear in part 2 to be published subsequently
CRAN	the production of aerodynamic forces by heat addition on external surfaces of aircraft the production of aerodynamic forces by heat addition on external surfaces of aircraft within the framework of linearized flow theory an equivalence between a fluid mass source a heat source and streamwise body forces is developed the equivalence between the fluid mass source and heat source was first noticed by hicks 2 and later by chu 3 using the equivalence the flow field produced by heat addition and by magnetohydrodynamical body forces can be computed examples for a two dimensional flat plate a delta wing an axially symmetric slender body and a wedge shaped afterbody are computed at subsonic and supersonic speeds the efficiency of lift or thrust production by surface heat addition is very low at subsonic speeds at supersonic speeds the efficiency is compared with the efficiency of a conventional turbojet powered aircraft configuration it is found that the efficiency of lift or thrust production by heat addition on two dimensional bodies is approximately the same as that for a turbojet powered two dimensional body the efficiency is somewhat higher at low supersonic mach numbers and behaves as decreasing to a constant value as increases on the other hand the efficiency of thrust production by heat addition increases linearly with mach number when heat is added on the rear surface of an axially symmetric afterbody of parabolic shape
CRAN	some aspects of non stationary airfoil theory and its practical application some aspects of non stationary airfoil theory and its practical application this paper consists of three notes on the theory of two  dimensional thin airfoils in non uniform motion oscillating airfoil are collected from an earlier paper and are presented in convenient forms for practical application rigid airfoil passing through a vertical gust pattern having a sinusoidal distribution of intensity the lift is determined as a function of the reduced frequency which in this case is proportional to the ratio of the airfoil chord and the wave length of the gust pattern and is presented in the form of a vector diagram it is shown that the lift acts at the quarter chord point of the airfoil at all times calculation of the amplitude of torsional oscillation of a fan blade operating in the wake of a set of pre rotation vanes in a numerical example the amplitude is found to be small even when the vanes are spaced so that the exciting frequency coincides with the natural frequency of the fan blade
CRAN	on some fourier transforms in the theory of non stationary flows on some fourier transforms in the theory of non stationary flows the growth of lift on a airfoil starting impulsively from rest to a uniform velocity has been given by wagner 1925 the steady state lift due to circulation on an airfoil oscillating sinusoidally and moving with uniform velocity has been given by theodorsen the present paper based essentially on the material of n a c a report no 629 by the author discusses some reciprocal relations of the nature of fourier transforms existing between the functions of wagner and theodorsen kussner 1936 has already shown that wagners function may be derived from theodorsens function by means of a superposition principle it is possible to utilize these fundamental functions to treat general problems in transient expression which is accurate to within 2 percent is given for wagners function this expression leads to a good approximate expression for theodorsens function in terms of the exponential integral instead of hankel functions an analogy is drawn between transient hydrodynamic flows and transient electrical flows kussner 1936 has introduced a function describing the growth of lift on an airfoil entering a sharp edged vertical gust region this function bears a certain relation to wagners function which is briefly discussed
CRAN	calculated responses of a large sweptwing airplane to continuous turbulence with flight test comparisons calculated responses of a large sweptwing airplane to continuous turbulence with flight test comparisons calculated responses of symmetrical airplane motions wing deformations and wing loads due to gusts are shown to compare favorably with available flight test results these calculated responses are based on random process theory five degrees of freedom lifting surface aerodynamics and one dimensional vertical turbulence the extent to which various degrees of freedom contribute to the responses is examined and in this connection the relative effects of static and dynamic aeroelasticity are determined
CRAN	calculated spanwise lift distributions influence functions and influence coefficients for unswept wings in subsonic flow calculated spanwise lift distributions influence functions and influence coefficients for unswept wings in subsonic flow spanwise lift distributions have been calculated for nineteen unswept wings with various aspect ratios and taper ratios and with a variety of angle of attack or twist distributions including flap and aileron deflections by means of the weissinger method with eight control points on the semispan also calculated were aerodynamic influence coefficients which pertain to a certain definite set of stations along the span and several methods are presented for calculating aerodynamic influence functions and coefficients for stations other than those stipulated the information presented herein can be used in the analysis of untwisted wings or wings with known twist distributions as well as in aeroelastic calculations involving initially unknown twist distributions
CRAN	aerodynamic forces on wings in non uniform motion aerodynamic forces on wings in non uniform motion the problem of determining the aerodynamic forces acting on wings of finite span in non uniform motion in an incompressible inviscid fluid is investigated the underlying theory is outlined in 2 and some known results for the case of an aerofoil of infinite span are included in 3 it is shown in 4 by the use of operational methods that the growth of lift function k s corresponding to a sudden unit change of incidence can be derived from the lift function corresponding to simple harmonic translational motion from results given by the writer for rectangular wings 1943 and tapered wings 1945 in simple harmonic motion the corresponding values of k s are determined the growth of lift function k s for a wing penetrating a uniform vertical gust can then be estimated as shown in 4 and 5 by the use of approximate formulae for the growth of lift curves given in fig 2 the aerodynamic forces corresponding to damped and growing translational oscillations are derived certain integrals involved in the theory are evaluated in appendix 1 and in appendix 2 the method of determining k s when k s is known is discussed in detail it is suggested that the aerodynamic forces acting on wings of finite span for any type of motion can best be derived from a knowledge of the forces corresponding to purely divergent motion which can be calculated by the methods outlined in this report
CRAN	calculated spanwise lift distributions and aerodynamic influence coefficients for swept wings in subsonic flow calculated spanwise lift distributions and aerodynamic influence coefficients for swept wings in subsonic flow spanwise lift distributions have been calculated for 61 swept wings with various aspect ratios and taper ratios and with a variety of angle of attack or twist distributions including flap and aileron deflections by means of the weissinger method with eight control points on the semispan also calculated for these plan forms were aerodynamic influence coefficients which pertain to a certain definite set of stations along the span the information presented herein can thus be used both in the analysis of untwisted wings or wings with known twist distributions and in aeroelastic calculations involving initially unknown twist distributions this paper supplements and is intended to be used in conjunction with naca tn 3014 where the same type of information calculated in the same way is presented for 19 unswept wings
CRAN	use of freon 12 as a fluid for aerodynamic testing use of freon 12 as a fluid for aerodynamic testing the thermodynamic properties of freon 12 have been investigated to determine the possibilities of the use of this gas as a fluid for aerodynamic testing the values of velocity of sound in freon 12 which are less than one half those in air are presented as functions of temperatures and pressure including measurements at room temperature the density of freon 12 is about four times that of air changes in state of freon 12 may be predicted by means of the ideal gas law with an accuracy of better than 1 percent at pressures below freon 12 is shown not to condense during an adiabatic expansion from normal conditions up to a mach number of 3 the values of the ratio of specific heats for freon 12 are lower than that for air and therefore an additional parameter is introduced which must be considered when comparisons are made of aerodynamic tests using freon 12 with those using air the time lag of the vibrational heat capacity of freon 12 to a change in temperature has been measured and found to be of the order of 2 x 10 second at atmospheric temperature and pressure this time is so short that no important energy dissipations should result in most engineering applications
CRAN	studies of the use of freon 12 as a wind tunnel testing medium studies of the use of freon 12 as a wind tunnel testing medium a number of studies relating to the use of freon 12 as a substitute medium for air in aerodynamic testing have been made the use of freon 12 instead of air makes possible large savings in wind tunnel drive power because of the fact that the ratio of specific heats is approximately 1 13 for freon 12 as compared with 1 4 for air some differences exist between data obtained in freon 12 and in air methods for predicting aerodynamic characteristics of bodies in air from data obtained in freon 12 however have been developed from the concept of similarity of the streamline pattern these methods derived from consideration of two dimensional flows provide substantial agreement in all cases for which comparative data are available these data consist of measurements throughout a range of mach number from approximately 0 4 to 1 2 of pressure distributions and hinge moments on swept and unswept wings having aspect ratios ranging from 4 0 to 9 0 including cases where a substantial part of the wing was stalled the freon charging and recovery system used for the langley low turbulence pressure tunnel is described
CRAN	study of effects of sweep on the flutter of cantilever wings study of effects of sweep on the flutter of cantilever wings an experimental and analytical investigation of the flutter of sweptback cantilever wings is reported the experiments employed groups of wings swept back by rotating and by shearing the angle of sweep ranged from 0 to 60 and mach numbers extended to approximately 0 85 a theoretical analysis of the air forces on an oscillating swept wing of high length chord ratio is developed and the approximations inherent in the assumptions are discussed comparison with experiment indicates that the analysis developed in the present report is satisfactory for giving the main effects of sweep at least for nearly uniform cantilever wings of high and moderate length chord ratios a separation of the effects of finite span and compressibility in their relation to sweep has not been made experimentally but some combined effects are given a discussion of some of the experimental and theoretical trends is given with the aid of several tables and figures
CRAN	investigation to determine effects of center of gravity location on the transonic flutter characteristics of a 45degree sweptback wing investigation to determine effects of center of gravity location on the transonic flutter characteristics of a 45degree sweptback wing an experimental investigation has been conducted in the 26 inch langley transonic blowdown tunnel to determine effects of center of gravity location on the transonic flutter characteristics of a 45degree swept back wing plan form of aspect ratio 4 0 and taper ratio 0 6 solid construction models of the plan form with streamwise naca 65a004 airfoil sections and center of gravity locations at approximately 34 percent chord 46 percent chord and 58 percent chord respectively were fluttered at several mach numbers between 0 8 and 1 35 it was found that for streamwise mach numbers from 0 8 to 1 0 the variation with mach number of the ratio of experimental flutter speed to a calculated incompressible flutter speed was not affected by center of gravity location however for mach numbers from 1 0 to 1 35 there was an increase in flutter speed ratio with mach number which was different for each center of gravity position data from wings with successively more forward center of gravity locations showed successively larger values of flutter speed ratio at mach numbers from 1 0 to
CRAN	calculation of flutter characteristics for finite span swept or unswept wings at subsonic and supersonic speeds by a modified strip analysis calculation of flutter characteristics for finite span swept or unswept wings at subsonic and supersonic speeds by a modified strip analysis a method has been developed for calculating flutter characteristics of finite span swept or unswept wings at subsonic and supersonic speeds the method is basically a rayleigh type analysis and is illustrated with uncoupled vibration modes although coupled modes can be used the aerodynamic loadings are based on distributions of section lift curve slope and local aerodynamic center calculated from three dimensional steady flow theory these distributions are used in conjunction with the effective angle of attack distribution resulting from each of the assumed vibration modes in order to obtain values of section lift and pitching moment circulation functions modified on the basis of loadings for two dimensional airfoils oscillating in a compressible flow are employed to account for the effects of oscillatory motion on the magnitudes and phase angles of the lift and moment vectors flutter characteristics have been calculated by this method for 12 wings of varying sweep angle aspect ratio taper ratio and center  of gravity position at mach numbers from 0 to as high as 1 75 comparisons of the results with experimental flutter data indicate that this method gives generally good flutter results for a broad range of wings
CRAN	method of controlling stiffness properties of a solid construction model wing method of controlling stiffness properties of a solid construction model wing a simple method is presented for controlling the bending and torsional stiffnesses of a solid construction model wing the method consists of weakening the wing by drilling holes through the wing normal to the chord plane aerodynamic continuity is maintained by filling the holes with a relatively soft material the important parameters controlling the stiffnesses are the amount of material removed by drilling the ratio of hole diameter to wing thickness and the plan form pattern of the holes data are given which may be used for predicting the stiffness of a model wing weakened in this manner
CRAN	investigation of wing flutter at transonic speeds for six systematically varied wing plan forms investigation of wing flutter at transonic speeds for six systematically varied wing plan forms an investigation of the effects of systematic variations in wing plan form on the flutter speed at mach numbers between 0 73 and 1 43 has been conducted in the 26 inch langley transonic blowdown tunnel the angle of sweepback was varied from 0degree to 60degree on wings of aspect ratio 4 and the aspect ratio was varied from 2 to 6 on wings with experimental flutter speed and the reference flutter speed calculated on the basis of incompressible two dimensional flow this ratio designated as the flutter speed ratio is plotted as a function of mach number for the various wings it is found that the flutter speed ratio increased rapidly past sonic speed for sweep angles of 45degree and less indicating a favorable effect of mach number for sweepback of mach number range of the tests reducing the aspect ratio had a favorable effect on the flutter speed ratio which was of the order of 100 percent higher for the aspect ratio 2 wing than for the aspect ratio 6 wing this percentage difference was nearly constant throughout the mach number range indicating that the effect of mach number was about the same for all aspect ratios tested
CRAN	the calculation of aerodynamic loading on surfaces of any shape the calculation of aerodynamic loading on surfaces of any shape the object of the report is to establish a routine method for the calculation of aerodynamic loads on wings of arbitrary shape the method developed is based on potential theory and uses a general mathematical formula for continuous loading on a wing which is equivalent to a double fourier series with unknown coefficients in order to evaluate the unknown coefficients the continuous loading is split up into a regular pattern of horseshoe vortices the strengths of which are proportional to the unknown coefficients and to standard factors which are given in a table the total downwash at chosen pivotal points is obtained by summing the downwashes due to the individual vortices a process which is simplified by the use of specially prepared tables of the properties of the horseshoe vortex by equating the downwash to the slope of the wing at each pivotal point simultaneous equations are obtained the solution of which defines the unknown coefficients the first layout involves a total of 76 vortices over the wing and a second layout involving a total of 84 is shown to be of superior accuracy the effect on the solution of the number of pivotal points is investigated and it is concluded that by a suitable choice it is unnecessary to use a large number results for a rectangular wing at with those obtained by other workers and it appears that there may be errors in published results in at least one of these cases immediate development includes the application to the calculation of the characteristics of actual sweptback wings including rotary derivatives and future development includes also applications in wind tunnel design and technique
CRAN	formulas for the supersonic loading lift and drag of flat swept back wings with leading edges behind the mach lines formulas for the supersonic loading lift and drag of flat swept back wings with leading edges behind the mach lines the method of superposition of linearized conical flows has been applied to the calculation of the aerodynamic properties in supersonic flight of thin flat swept back wings at an angle of attack the wings are assumed to have rectilinear plan forms with tips parallel to the stream and to taper in the conventional sense the investigation covers the moderately supersonic speed range where the mach lines from the leading edge apex lie ahead of the wing the trailing edge may lie ahead of or behind the mach lines from its apex the case in which the mach cone from one tip intersects the other tip is not treated formulas are obtained for the load distribution the total lift and the drag due to lift for the cases in which the trailing edge is outside the mach cone from its apex supersonic trailing edge the formulas are complete for the wing with both leading and trailing edges behind their respective mach lines a degree of approximation is necessary it has been found possible to give practical formulas which permit the total lift and drag to be calculated to within 2 or 3 percent of the accurate linearized theory value the local lift can be determined accurately over most of the wing but the trailing edge tip region is treated only approximately charts of some of the functions derived are included to facilitate computing and several examples are worked out in outline
CRAN	atmospheric entries with vehicle lift drag ratio modulated to limit deceleration and rate of deceleration vehicles with maximum lift drag ratio of 0 5 atmospheric entries with vehicle lift drag ratio modulated to limit deceleration and rate of deceleration vehicles with maximum lift drag ratio of 0 5 an analysis has been made of atmosphere entries for which the vehicle lift drag ratio was modulated to maintain specified maximum decelerations and or maximum deceleration rates the part of the vehicle drag polar used during modulation was from maximum lift coefficient to minimum drag coefficient the entries were at parabolic velocity and the vehicle maximum lift drag ratio was 0 5 two dimensional trajectory calculations were made for a nonrotating spherical earth with an exponential atmosphere the results of the analysis indicate that for a given initial flight path angle modulation generally resulted in a reduction of the maximum deceleration to 60 percent of the unmodulated value or a reduction of maximum deceleration rate to less than 50 percent of the unmodulated rate these results were equivalent for a maximum deceleration of 10g to lowering the undershoot boundary 24 miles with a resulting decrease in total convective heating to the stagnation point of 22 percent however the maximum convective heating rate was increased 18 percent the maximum radiative heating rate and total radiative heating were each increased about 10 percent
CRAN	the use of aerodynamic lift during entry into the earths atmosphere the use of aerodynamic lift during entry into the earths atmosphere by employing aerodynamic lift during entry into the earths atmosphere at either orbital or escape velocity the range of allowable entry angles for a prescribed peak deceleration is greatly increased while the total heat energy transferred to the vehicle can be held to about the same value as for a nonlifting vehicle only modest lift drag ratios are required beyond peak g to prevent the deceleration from exceeding the peak value or to prevent the vehicle from skipping out of the earths atmosphere thus the difficult guidance and control problem is greatly alleviated in particular for return from the moon or other planets the necessity for multiple pass drag braking is eliminated
CRAN	modulated entry modulated entry the technique of modulation or variable coefficients is discussed and the analytical formulation is reviewed representative numerical results of the use of modulation are shown for the lifting and nonlifting cases these results include the effects of modulation on peak acceleration entry corridor and heat absorption results are given for entry at satellite speed and escape speed the indications are that coefficient modulation on a vehicle with good lifting capability offers the possibility of sizable loading reductions or alternatively wider corridors thus steep entries become practical from the loading standpoint the amount of steepness depends on the acceptable heating penalty the price of sizable fractions of the possible gains does not appear to be excessive
CRAN	approximate analysis of atmospheric entry corridors and angles approximate analysis of atmospheric entry corridors and angles a simple closed form solution for the achievable corridor depths and entry angles as a function of g load limit entry velocity and vehicle aerodynamics and thermodynamics is developed for two modes of vehicle operation constant angle of attack and modulated angle of attack for constant angle of attack operation at maximum negative lift coefficient on the overshoot bound and at an angle of attack between zero and that for maximum lift drag ratio on the undershoot bound gives the deepest corridor for modulated angle of attack operating at maximum negative lift coefficient on the overshoot bound and modulating the angle of attack from maximum positive lift coefficient to zero on the undershoot bound give the deepest corridor the modulated angle of attack gives corridor depths two to four times larger than the fixed angle of attack for both cases the corridor depth is increased by increasing maximum lift drag ratio increasing g limit and decreasing entry velocity consideration of hot gas radiation places a limit on the maximum angle of attack for either mode of operation if a maximum free stream reynolds number limit must be placed on the vehicle to ensure a laminar boundary layer the deep atmospheric penetrations associated with configurations with high lift drag ratio may be ruled out both of these thermodynamic considerations reduce the acceptable corridor depth below the value calculated from aerodynamic considerations alone
CRAN	radiative heat transfer during atmosphere entry at parabolic velocity radiative heat transfer during atmosphere entry at parabolic velocity stagnation point radiative heating rates for manned vehicles entering the earths atmosphere at parabolic velocity are presented and compared with corresponding laminar convective heating rates the calculations were made for both nonlifting and lifting entry trajectories for vehicles of varying nose radius weight to area ratio and drag it is concluded from the results presented that radiative heating will be important for the entry conditions considered
CRAN	effects of simulated rocket jet exhaust on stability and control of a research type airplane configuration at a mach number of 6 86 effects of simulated rocket jet exhaust on stability and control of a research type airplane configuration at a mach number of 6 86 an investigation has been undertaken in the langley 11 inch hypersonic tunnel at a free stream mach number of 6 86 to determine the jet interference effects at high jet static pressure ratios on the stability and control of a research type airplane configuration compressed air tests with a jet exhausting from the base of the fuselage were conducted over a reynolds number range of 0 57 x 10 to and over a jet static  pressure ratio range of 0 to 1460 the results of these tests indicated that the operation of the jet induced a sizable separated flow region over the vertical  and horizontal tail surfaces which could be approximately duplicated at low angles of attack by use of metal jet boundary simulators the results of force tests during which these metal jet boundary simulators were used indicated that this separated flow region caused a large reduction in the longitudinal stability and control and a smaller reduction in the lateral and directional stability and control by extending the divergent section of the nozzle and thus reducing the jet static pressure ratio these losses were diminished
CRAN	effects of jet billowing on stability of missile type bodies at mach 3 85 effects of jet billowing on stability of missile type bodies at mach 3 85 the interference effects of a billowing jet on the forces and moments of two missile type bodies were investigated in the nasa lewis 2 by 2 foot mach 3 85 wind tunnel to simulate a rocket jet pressurized nitrogen was exhausted from an annular sonic nozzle the results indicate that for both models the stability parameter moment coefficient with angle of attack in the region of zero angle of attack was favorably influenced by the interference resulting from separation due to jet billowing schlieren photographs are presented that show the separation due to the jet billowing at various pressure ratios and angles of attack
CRAN	exploratory tests of the effects of jet plumes on the flow over cone  cylinder flare bodies exploratory tests of the effects of jet plumes on the flow over cone  cylinder flare bodies schlieren photographs have been taken of the flow over cone cylinder flare bodies to study the extent of boundary layer separation due to the presence of rocket jet plumes tests were made of three cone cylinder flare configurations in the langley 11 inch hypersonic tunnel at a mach number of 9 65 and in the langley unitary plan wind tunnel at a mach number of 4 65 with two additional configurations the stream reynolds number varied from approximately 317 000 to 582 000 based on model length the conical flares had half angles of 7 or 13 and contained one of two test nozzles with a design mach number of 3 72 or 4 53 the test nozzles were operated with compressed air and were designed to simulate a solid propellant rocket motor operating at altitudes between to free stream static pressure ratio varied from jet off to 1 150 for the test nozzle with a design mach number of 3 72 and from jet off to mach number of 4 53 for most of the tests the angle of attack range was 0 to  4 some additional tests were made at 2 and 4 measurements taken from flow pictures indicated that at zero angle of attack on all configurations tested with jet on the boundary layer separates ahead of the flare cylinder juncture and the separation point moves toward the cone cylinder juncture with an increase in pressure ratio increasing angle of attack reduced the extent of boundary layer separation on the windward side as did increasing the stream mach number from 4 65 to 9 65 other parameters which tended to reduce the extent of boundary layer separation were number b decreasing stream reynolds number and c displacing nozzle exit rearward
CRAN	aerodynamic investigation of a parabolic body of revolution at mach number of 1 92 and some effects of an annular supersonic jet exhausting from the base aerodynamic investigation of a parabolic body of revolution at mach number of 1 92 and some effects of an annular supersonic jet exhausting from the base an aerodynamic investigation of a parabolic body of revolution was conducted at a mach number of 1 92 with and without an annular supersonic jet exhausting from the base measurements with the jet inoperative were made of lift drag pitching moment radial and longitudinal pressure distributions and base pressures with the jet in operation measurements were made of the pressures over the rear of the body with the primary variables being angle of attack ratio of jet velocity to freestream velocity and ratio of jet pressure to stream pressure the results with the jet inoperative showed that the radial pressures over the body varied appreciably from the distribution generally employed in most approximate theories the linearized solutions for lift pitching moment and center of pressure gave relatively poor predictions of the experimental results an analysis of several theoretical methods for calculating pressure distribution and wave drag showed that some methods gave results in considerable disagreement with experimental values maximum effects of the jet were obtained at the lower ratio of jet velocity to stream velocity and the highest ratio of jet pressure to stream pressure these effects amounted to a slight decrease in fore drag a reduction in lift and a shift of center of pressure in a destabilizing direction
CRAN	investigation of a two step nozzle in the langley 11in investigation of a two step nozzle in the langley 11in hypersonic tunnel flow surveys have been made in the first of several nozzles to be investigated in the langley 11 inch hypersonic tunnel the nozzle was designed by the method of characteristics for a mach number of 6 98 two step expanded the air in the horizontal plane to a mach number of 4 36 and the second in the vertical plane to a mach number of 6 98 the test results showed that although a maximum mach number of about 6 5 was obtained the flow in the test section was not sufficiently uniform for quantitative wind tunnel test purposes deviations from the design flow were traced to the presence of a thick boundary layer which developed in the first step along the parallel walls
CRAN	investigation of the flow through a single stage two dimensional nozzle in the langley 11in hypersonic tunnel investigation of the flow through a single stage two dimensional nozzle in the langley 11in hypersonic tunnel flow surveys have been made in the second of several nozzles to be investigated in the langley 11 inch hypersonic tunnel the single stage two dimensional nozzle was designed by the method of characteristics for a mach number of 7 08 without boundary layer corrections the test results show that reasonably uniform flow at an average mach number of about 6 86 was obtained in a central region of the stream at the test section this region had a cross section nearly 5 inches square and had a deviation from uniform flow of less than 1 percent in mach number and 0 3 in flow angle an increase in mach number of about 3 percent occurred during test runs of about 60 seconds duration because of distortions of the boundaries at the first minimum due to nonuniform heating of the nozzle blocks during the tests
CRAN	boundary layer displacement effects in air at mach numbers of 6 8 and 9 6 boundary layer displacement effects in air at mach numbers of 6 8 and 9 6 measurements are presented for pressure gradients induced by a laminar boundary layer on a flat plate in air at a mach number of 9 6 and for the drag of thin wings at a mach number of about 6 8 and zero angle of attack the pressure measurements at a mach number of 9 6 were made in the presence of substantial heat transfer from the boundary layer to the plate surface the measured pressure distribution on the surface of the plate was predicted with good accuracy by a modification to insulated plate displacement theory which allows for the effect of the heat transfer and temperature gradient along the surface on the boundary layer displacement thickness the total drag of thin wings with square and delta plan forms was measured at a nominal mach number of 6 8 over a reasonably wide range of reynolds numbers the total drag was found to be greater than can be explained by adding a classical value of laminar skin friction to the estimated pressure drag the difference is in general explained by the increase in skin friction 20 to 40 percent caused by the boundary layer induced pressures
CRAN	secondary flow fields embedded in hypersonic shock layers secondary flow fields embedded in hypersonic shock layers when a ramp or other compression surface is located in a locally supersonic region behind a hypersonic bow shock wave it generates a secondary shock wave the ramp flow disturbance may be viewed as an embedded newtonian impact flow if the embedded shock layer is thin examination of the applicability of newtonian flow theory to cones and wedges in uniform streams suggests that this theory can be expected to give a useful approximation to the surface pressures a pressure equation based on this concept predicts a number of interesting things first pressures can differ from simple newtonian theory by factors of 1 5 to 3 for example on flare stabilizers on blunt nosed bodies of revolution pressures are lower than newtonian and diminish with increasing flight speed in the hypersonic speed range the calculated pressures vary over the flare surface as a result of the nonuniformity of its incident stream and depend on the axial location of the flare in the case of a flap mounted on a large angled blunt nosed cone the pressure coefficients vary from 1 to 5 through the variable entropy layer a pressure coefficient of 5 greater than the maximum possible in newtonian flow can occur because the compression process is more efficient than a single shock wave process on areas of the flap that protrude through the main bow wave the pressure coefficient should revert to the simple newtonian value equations are developed for the initial slopes of the normal force and pitching moment curves of a flare stabilizer in the simplest case these differ from conventional newtonian theory by the ratio of local dynamic pressure to free stream dynamic pressure this ratio takes values as low as 0 1 in some of the examples considered
CRAN	compressive buckling of simply supplorted plates with longitudinal stiffeners compressive buckling of simply supplorted plates with longitudinal stiffeners charts are presented for the analysis of the stability under compression of simply supported rectangular plates with one two three and an infinite number of identical equally spaced longitudinal stiffeners that have zero torsional stiffness
CRAN	compressive buckling of simply supported plates with transverse stiffeners compressive buckling of simply supported plates with transverse stiffeners charts are presented for the analysis of the stability under longitudinal compression of simply supported rectangular plates with several equally spaced transverse stiffeners that have both torsional and flexural rigidity
CRAN	compression tests on circular cylinders stiffened longitudinally by closely spaced z section stringers compression tests on circular cylinders stiffened longitudinally by closely spaced z section stringers six circular cylinders stiffened longitudinally by closely spaced z section stringers were loaded to failure in compression the results obtained are presented and compared with available theoretical results for the buckling of orthotropic cylinders the results indicate that the large disparity that exists between theory and experiment for unstiffened compression cylinders may be significantly smaller for stiffened cylinders
CRAN	simplified analysis of general instability of stiffened shells in pure bending simplified analysis of general instability of stiffened shells in pure bending although much work has been done to develop a theory for the failure of shells by general instability there is at present no simple method by which the size of the frames may be determined for any given diameter bending moment and frame spacing such a method is needed in determining the optimum design for stiffened shells to be used as a basis for weight analysis of fuselages and other shell structures in an extension of the work done for the rand corporation a simple coefficient has been determined for this purpose since it appears that this method may also be useful in design calculations a brief description is presented below
CRAN	large deflections of structures subjected to heating and external loads large deflections of structures subjected to heating and external loads the method of direct formulation of the stiffness matrix is extended to include the effects of nonuniform heating and large deflections the purpose is to develop an analytical tool for the treatment of actual structures in the solution of aeroelastic problems the relations between forces and deflections must be determined the usual stiffness matrix formulation of this relationship is limited to small temperature changes and small deflections for large temperature changes additional terms are required also the problem becomes geometrically nonlinear when large deflections are involved to overcome the inherent difficulties of the nonlinear problem for practical structures either an iterative or a step  by step procedure must be used the force deformation relations necessary for this step by step or iterative approach are derived for an axially loaded member and for a plate element including the effects of thermal strains
CRAN	non linear analysis of heated cambered wings by the matrix force method non linear analysis of heated cambered wings by the matrix force method various extensions of the matrix force method for complex structure analysis are presented and illustrated with the objective of expanding its range to handle the problems likely to be encountered in advanced vehicle wing design methods are covered in detail for 1 determining the change in flexibility that occurs when thermal stresses are present and also how large these stresses must be to cause buckling 2 including the non linear effect of large deflections by an iterative procedure and 3 analyzing a wing that is initially slightly cambered and warped with either or both of the aforementioned effects present formulas are given for calculating the input matrix terms as are the matrix equations and supporting theoretical discussion an example illustrates the nature and magnitude of the effects being examined
CRAN	a characteristic type of instability in the large deflections of elastic plates a characteristic type of instability in the large deflections of elastic plates part 1 from a general equation governing the bending of thin elastic plates into certain types of surfaces of revolution are derived expressions for the behaviour of rectangular plates with initial curvatures subjected to pure bending about one axis it is found that such plates exhibit the type of instability characteristic of thin walled structures which depend for their stiffness on curvature curves are drawn showing the deformation suffered by such plates and an expression for the critical bending moment at which instability occurs is obtained experimental results show satisfactory agreement part 2 the analysis of part 1 is extended to deal with the case of flat square or rectangular plates loaded by distributed bending moments applied to all four edges curves are drawn to describe their behaviour and they are found to exhibit the characteristic instability displayed by thin walled curved structures experimental verification is satisfactory
CRAN	an experimental investigation of the interaction between shock waves and boundary layers an experimental investigation of the interaction between shock waves and boundary layers an account is given of an investigation into the interaction between the boundary layer on a flat plate and a shock wave produced either externally by a wedge in the supersonic mainstream or from within the boundary layer by a wedge held in contact with the plate a wide range of free stream mach numbers boundary layer reynolds numbers and shock strengths has been covered shock strength being defined as the ratio of the static pressure downstream of the shock to the static pressure upstream of it variations in these parameters can have large effects on the interaction and there are also large differences between cases with externally generated shocks and cases where the shock is generated from within the boundary layer the investigation has thrown light on the physical mechanisms involved it is found that many of the major features of the interaction arise because the boundary layer separates from the surface ahead of the shock wave the conditions under which separation occurs and the behaviour of the separated boundary layer thus have important effects in terms of which for example the differences between the interactions observed with laminar and with turbulent boundary layers may be explained
CRAN	approximate calculation of the laminar boundary layer approximate calculation of the laminar boundary layer after analyzing a large class of boundary layer velocity profiles the author discovered that the functions l m and h m for all such cases differ only slightly from each other over the whole range of positive and negative pressure gradients here l m and h are defined by being the velocity component in the x direction and u the value of u at the edge of the boundary layer and and the displacement and momentum thickness respectively based on this discovery an approximate method is proposed by constructing two universal curves l m and h m for all conceivable boundary layer flows found in practice once these are chosen karmans momentum integral can be written in the form v being the kinematic viscosity coefficient and can be integrated numerically as examples both howarths and hartrees tained is considered good for practical purposes
CRAN	the compressible laminar boundary layer with heat transfer and arbitrary pressure gradient the compressible laminar boundary layer with heat transfer and arbitrary pressure gradient an approximate method for the calculation of the compressible laminar boundary layer with heat transfer and arbitrary pressure gradient based on thwaites correlation concept is presented the method results from the application of stewartsons transformation to prandtls equations which yeilds a nonlinear set of two first order differential equations these equations are then expressed in terms of dimensionless parameters related to the wall shear the surface heat transfer and the transformed free stream velocity thwaites concept of the unique interdependence of these parameters is assumed the evaluation of these quantities is then carried out by utilizing exact solutions recently obtained with the resulting relations methods are derived for the calculation of the two dimensional and axially symmetric laminar boundary layer with arbitrary free stream velocity distribution mach number and surface temperature level the combined effect of heat transfer and pressure gradient is demonstrated by applying the method to calculate the characteristics of the boundary layer on thin supersonic surfaces and in a highly cooled convergent divergent axially symmetric rocket nozzle
CRAN	a theoretical investigation of the effects of mach number reynolds number wall temperature and surface curvature on laminar separation in supersonic flow a theoretical investigation of the effects of mach number reynolds number wall temperature and surface curvature on laminar separation in supersonic flow laminar separation in supersonic flow is investigated by an extension of stratfords method it is assumed that separation is of the usual practical type taking place upstream of the shock wave or other agency provoking it the results of the analysis agree well in most respects with experiment
CRAN	three dimensional viscous wakes three dimensional viscous wakes the velocity fields of three dimensional viscous wakes are examined with the use of the boundary layer approximations osoens linearization of the convective terms and the assumption of constant fluid properties transform methods yield solutions for general types of initial conditions as an illustration the axial velocity distribution of a wake whose initial isovels lines of constant velocity are of elliptic shape and their decay to axial symmetry are demonstrated both laminar and turbulent flows are considered
CRAN	steady motion of a sphere oseens criticism and solution steady motion of a sphere oseenss criticism and solution the formula of stokes for the resistance experienced slowly moving sphere has been employed in physical researches of fundamental importance as a means of estimating the size of minute globules of water and thence the number of globules contained in a cloud of given mass consequently the conditions of its validity has been much discussed both from the experimental and from the theoretical side
CRAN	some remarks on the flat plate boundary layer some remarks on the flat plate boundary layer the authors discuss the solutions for the flow of a viscous incompressible fluid near the leading edge of a semi infinite flat plate without pressure gradient the oseen linearization is employed which approximates the equations of motion and continuity by where are the coordinate directions the corresponding velocity components and the uniform free stream velocity which is parallel to the plate defining a perturbation stream function by the differential equation to be solved is with boundary conditions far from the plate and when y 0 and the authors discuss the problem by applying the two dimensional fourier transform and obtain an explicit solution for the velocity gradient at the plate which is in disagreement with the result of the blasius solution from this the authors conclude that it would be more appropriate to use a velocity other than in the linearization of the equations of motion and suggest replacing by where this choice does not affect the solution far from the plate but gives on the plate and in comparison with blasius solution indicates that c 0 35 the solution of the modified oseen equation with this value of c then seems acceptable as the approximate solution in the region intermediate between the stokes flow and the free stream on the basis of these considerations the authors suggest an iteration procedure for obtaining the exact solution for the above problem as well as a solution for the plate of finite length
CRAN	axisymmetric free mixing with swirl axisymmetric free mixing with swirl viscous laminar axially symmetric free mixing with small moderate and large swirl is investigated by a boundary layer type of analysis with integral methods moderate and small swirls are formally the same differing only in the order of their associated radial pressure gradients neither induces significant axial pressure gradients consequently their effect on the axial flow is negligible for moderate and small swirl an interesting feature is the swirl decay in both compressible and incompressible flow it is shown that jet swirl decays more rapidly than wake swirl whereas both swirls decay more rapidly than the non uniformity in axial velocity large swirl generates axial pressure gradients as well as large radial pressure gradients and therefore alters the streamwise flow examples calculated for incompressible flow show that the wake is lengthened by large swirl it is expected that this effect will be diminished in the presence of higher free stream mach numbers which lead to decreased densities due to decreased centrifugal effects decreased radial pressure gradients and decreased axial pressure gradients
CRAN	on axially symmetric turbulent compressible mixing in the presence of initial boundary layer on axially symmetric turbulent compressible mixing in the presence of initial boundary layer recent experimental results have shown that the mixing of heterogeneous gases having an initial velocity ratio close to unity occurs faster than is predicted by classical eddy viscosity theory the theoretical analysis of two uniform streams of different gases but of nearly equal velocity performed with the usual assumptions for eddy viscosity and prandtl number equal to a constant shows that mixing will take place very slowly i e at the rate corresponding to laminar diffusion it has been suggested that the difference between analysis and experiment could be attributed to the presence of a boundary layer in the experiments it is the purpose of this note to show that the use of the classical eddy viscosity law admitting the existence of a boundary layer is not sufficient to explain the rapid mixing that is observed physically instead it is shown that rapid mixing can be explained on the basis of a different eddy viscosity law as was suggested in ref 1 these conclusions are obtained through application of the analysis presented briefly below
CRAN	nose drag in free molecule flow and its minimization nose drag in free molecule flow and its minimization the superaerodynamic nose drag of a body in a free molecule flow involves two parameters the speed ratio s between ordered and random molecular motions modified mach number and the temperature ratio between the solid surface and undisturbed gas simplifications of the drag formula are obtained at hypersonic as well as low subsonic extremes to minimize the drag on a nose of specified length and base radius the ordinary method of calculus of variation was found inadequate a generalized approach has accordingly been developed and the specification of end conditions is discussed at length results of the present investigation indicate that in all cases an optimum nose requires a flat tip the optimum nose curve for the hypersonic extreme does not depend on the temperature ratio but that for the low subsonic extreme varies in the following manner for a hot body the curve is convex for a cold body concave an optimum solution exists in a restricted range of specification only with prescribed tip and base radii the admissible nose length is bounded below for the cases of hypersonic and low subsonic hot body and bounded above for the case of low subsonic cold body a vanishing tip radius leads to an infinitely long nose in the former and a vanishing nose in the latter case optimum nose curves for several temperature ratios at the low subsonic extreme as well as the one for hypersonic extreme are presented it is observed that at the low subsonic extreme with the hot body solution asymptotically approaches the hypersonic solution  i e a slender conventional warhead with a flat tip whereas with the cold body solution asymptotically approaches the minimal surface solution  i e tip radius a flat disc
CRAN	theoretical analysis of turbulent mixing of reactive gases with application to supersonic combustion of hydrogen theoretical analysis of turbulent mixing of reactive gases with application to supersonic combustion of hydrogen the turbulent mixing of an axisymmetric jet of a reactive gas is considered by assuming a convenient model for the compressible eddy viscosity the momentum equation is reduced to a form amenable to approximate solution the resulting velocity distribution in both incompressible and compressible flows is in reasonable agreement with experiment the usual assumptions with respect to chemical behavior namely either frozen or equilibrium flow and to unity lewis numbers and prandtl number are employed the theoretical results for chemical equilibrium are shown to be in reasonable agreement with experimental data from low speed hydrogen flames a numerical example of interest in connection with a hypersonic air breathing vehicle is carried out in detail
CRAN	an approximate solution for the axisymmetric jet of a laminar compressible fluid an approximate solution for the axisymmetric jet of a laminar compressible fluid an extension of the modified oseen method of carrier based on the linearization of the viscous term of the von mises transformation is presented the method is employed to determine the velocity field associated with the laminar axisymmetric jet flow of a compressible gas with an arbitrary but constant external flow the approximate solution is shown to be in good agreement with the exact numerical calculation of pai in many boundary layer problems it is not possible to make the assumption of flow similarity the solution in these cases can be obtained either by laborious finite difference techniques or by resort to approximate solutions carrier and lewis 1 and more recently carrier 2 have suggested a method of obtaining approximate solutions to problems involving convection and diffusion this method termed by carrier the modified oseen method overcomes an essential difficulty of integral methods namely the generation of reasonable profiles it is well known that the integral method gives accurate results only if the analytical profiles represent closely the true profiles according to the modified oseen method the convective operator in the original partial differential equation is replaced by a linear one the resulting equation for the boundary layer problem is the heat conduction equation which can be treated by well known techniques it is the purpose of this paper to indicate a modification of this procedure and to demonstrate its simplicity and accuracy by treating the axisymmetric laminar flow of a compressible gas with arbitrary but constant external flow the modification is based on the use of the von mises transformation with a subsequent linearization of the viscous term rather than the linearization of the convective term pais problem 3 originally treated by a finite difference technique is considered to illustrate the effectiveness of this method
CRAN	some applications in physics of the p function some applications in physics of the p function the mathematical background and typical applications in physics are presented for a recently tabulated function because of its properties the p function should prove to be a useful aid in the solution of certain problems in applied mathematics involving surface integrations in cylindrical coordinates a tabulation of the function in its normalized form is appended particular attention is paid to the application of the p function to multiple scattering problems involving circular symmetry
CRAN	theoretical investigation of the flow field about blunt nosed bodies in supersonic flight theoretical investigation of the flow field about blunt nosed bodies in supersonic flight a numerical method ofr obtaining the solution to the inverse problem of the flow behind a given detached shock to any desired accuracy is presented the cases of zero and small incidence are considered the combination of sets of such solutions satisfying prescribed boundary conditions body shapes is described particular attention is devoted to the analysis of the sonic and subsonic region of the flow field convergence and stability of the stepwise integration from the shock in the elliptic region are discussed numerical examples are also included
CRAN	blunt cone pressure distributions at hypersonic mach numbers blunt cone pressure distributions at hypersonic mach numbers the static pressure distributions on the surface of a blunted 7 5 degree half angle cone have recently been experimentally determined in the cal 48 inch hypersonic shock tunnel this facility and the associated instrumentation are described in detail in ref 1 these tests covered a mach number range of 8 to 18 at a reynolds number per foot of approximately 1 times 10 to the 5th power the models included one flat faced cone and two hemispherically blunted cones
CRAN	hypersonic flight and the re entry problem hypersonic flight and the re entry problem paper reviews the possibilities and some of the main problems of three types of long range vehicle the ballistic the glide and the skip rocket performance assessments are made on the basis of an ingenious if debatable conversion of the vehicle characteristics to the breguet formula the problems of aerodynamic heating aerodynamic loads and stability are briefly discussed and other aspects of hypersonic flight free molecule flow dash are touched upon the results on the whole favor the glide vehicle for manned flight the subsequent discussion on the paper includes references to multistaging and the use of high energy fuels
CRAN	the problem of obtaining high lift drag ratios at supersonic speeds the problem of obtaining high lift drag ratios at supersonic speeds the importance of the lift to drag ratio is well known to all aircraft designers since it gives to a great extent the aerodynamic efficiency of the airplane aerodynamic efficiency however is only one component of the grand compromise that a completed airplane represents at subsonic speeds lift drag ratios of well over 200 have been measured in wind tunnels on airfoil sections but few powered aircraft have attained lift to drag ratio value of 20 it is invariably true that the requirements of stability and control structure and flight operation all contribute to reducing the design lift to drag ratio considerably below those exotic values which can be predicted from unrestricted aerodynamic theory if however a certain range or operating efficiency is required there is most certainly a minimum if we examine the range equation we see that range is proportional to the lift drag ratio the thermopropulsive efficiency and the logarithm of the initial to final weight ratio the appearance of the lift drag ratio as a linear factor in the range equation indicates that every attempt should be made to increase lift to drag ratio however the search for higher lift to drag ratio may lead to strange and unorthodox configurations most frequently such configurations are ruled out by the adverse effects of their geometry on the weight ratios in the present paper we will deal with the maximum lift drag ratio problem for conventional configurations having a wing and a body in close proximity to each other no attempt will be made to select a particular configuration as being the best however the promising direction to go from the aerodynamic view will be stressed with the understanding that the other factors may outweight the aerodynamics
CRAN	effect of mach number on boundary layer transition in the presence of pressure rise and surface roughness on an ogive cylinder body with cold wall conditions effect of mach number on boundary layer transition in the presence of pressure rise and surface roughness on an ogive cylinder body with cold wall conditions the effect of mach number variation from 1 8 to 7 4 on boundary layer transition was investigated on a slender fin stabilized ogive cylinder body in free flight at a constant length reynolds number of 13 8 million the wall to free stream temperature ratio was constant at a value of 1 0 below mach number 4 5 and at a value of of the test showed that increasing mach number had a very favorable effect of increasing the extent of the laminar boundary layer for a given surface roughness the transition data when plotted as a function of a factor indicative of heat transfer showed that heat transfer was possibly responsible for a good deal of the increase in transition reynolds number with mach number transition was found to occur farther forward on the sheltered side of the body than on the windward side for angles of attack as low as 0 4 and for all mach numbers the pressure rise along sheltered side stream lines was examined and it was found that the pressure rise coefficient at the transition point showed no variation with mach number data from other sources for different test conditions when reduced to values of pressure rise coefficient were also found to correlate well with that of the present investigation with the exception of data at low subsonic mach numbers these present results also show that mach number surface roughness pressure rise and length reynolds number all affected boundary layer transition in the region of theoretical infinite laminar stability to small two dimensional disturbances as calculated for a flat plate with zero pressure gradient
CRAN	the solution of the equations of the laminar boundary layer for schubauers observed pressure distribution for an elliptic cylinder the solution of the equations of the laminar boundary layer for schubauers observed pressure distribution for an elliptic cylinder the solution of the equations of the laminar boundary layer has been carried out for the pressure distribution for an elliptic cylinder of axial ratio 2 96 1 with its major axis in the direction of the incident stream the solution has been obtained by the method of hartree and womersley in applying this method the derivatives parallel to the boundary are replaced by finite differences so that the partial differential equation of the boundary layer is replaced by an ordinary equation relating the velocity distribution through the boundary layer at one section to that at another at an interval upstream by two independent integrations covering the same range by finite intervals of different sizes it is possible to estimate the errors involved in replacing the derivatives by finite differences and so to correct for these errors the process of solution requires the values of the pressure gradient along the solid boundary and there is a certain tolerance in the derivation of the pressure gradient distribution from a limited number of observed values of pressure an analysis of schubauers pressure distribution is outlined and the results were used for the main solution calculated it is found that the solution for the distribution of pressure gradient so derived does not give separation of the boundary layer from the solid boundary whereas the actual flow does separate it is found that the calculated solution is very sensitive to the pressure distribution and a comparatively small modification of the pressure distribution gives a solution which does indicate separation close to the point at which separation is observed to occur the solution with this pressure distribution also gives very good agreement with the observed velocity distribution through the boundary layer at points upstream from separation
CRAN	on the theory of laminar boundary layer involving separation on the theory of laminar boundary layer involving separation the paper presents a mathematical discussion of the laminar boundary layer which was developed with a view of facilitating the investigation of those boundary layers in particular for which the phenomenon of separation occurs the treatment starts with a slight modification of the form of the boundary layer equation first published by von mises two approximate solutions of this equation are found one of which is exact at the outer edge of the boundary layer while the other is exact at the wall the final solution is obtained by joining these two solutions at the inflection points of the velocity profiles the final solution is given in terms of a series of universal functions for a fairly broad class of potential velocity distributions outside of the boundary layer detailed calculations of the boundary layer characteristics are worked out for the case in which the potential velocity is a linear function of the distance from the upstream stagnation point finally the complete separation point characteristics are determined for the boundary layer associated with a potential velocity distribution made up of two linear functions of the distance from the stagnation point it appears that extensions of the detailed calculations to more complex potential flows can be fairly easily carried out by using the explicit formulae given in the paper
CRAN	a theoretical calculation of the laminar boundary layer around an elliptic cylinder and its comparison with experiment a theoretical calculation of the laminar boundary layer around an elliptic cylinder and its comparison with experiment the author in conjunction with th von karman has recently given a new method of approximate integration of the prandtl boundary layer equations which was developed in order to treat cases in which separation of a laminar boundary layer might be expected the method was developed because some doubt was felt as to the accuracy with which the well known pohlhausen analysis would describe conditions in the neighborhood of such a separation point numerical calculations were carried out for certain cases involving theoretical simplifications and very considerable discrepancies were found between the results of the new and pohlhausen methods the method was also used in developing a theory for the maximum lift coefficient of certain classes of airfoils this theory gave satisfactory agreement with experiment but no direct experimental check on the boundary layer analysis itself has been given up to the present
CRAN	air flow in a separating laminar boundary layer air flow in a separating laminar boundary layer the speed distribution in a laminar boundary layer on the surface of an elliptic cylinder of major and minor axes 11 78 and 3 98 inches respectively has been determined by means of a hot wire anemometer the direction of the impinging air stream was parallel to the major axis special attention was given to the speed distribution in the region of separation and to the exact location of the point of separation an approximate method developed by k pohlhausen for computing the speed distribution the thickness of the layer and the point of separation is described in detail and speed distribution curves calculated by this method are presented for comparison with experiment good agreement is obtained along the forward part of the cylinder but pohlhausens method fails shortly before the separation point is reached and consequently cannot be used to locate this point the work was carried out at the national bureau of standards with the cooperation and financial assistance of the national advisory committee for aeronautics
CRAN	analysis and calculation by integral methods of laminar compressible boundary layer with heat transfer and with and without pressure gradient analysis and calculation by integral methods of laminar compressible boundary layer with heat transfer and with and without pressure gradient a survey of integral methods in laminar boundary layer analysis is first given a simple and sufficiently accurate method for practical purposes of calculating the properties layer in an axial pressure gradient with heat transfer at the wall is then presented for flow over a flat plate the method is applicable for an arbitrarily prescribed distribution of temperature along the surface and for any given constant prandtl number close to unity for flow in a pressure gradient the method is based on a prandtl number of unity and a uniform wall temperature a simple and accurate method of determining the separation point in a compressible flow with an adverse pressure gradient over a surface at a given uniform wall temperature is developed the analysis is based on an extension of the karman pohlhausen method to the momentum and thermal energy equations in conjunction with fourth  and especially higher degree velocity and stagnation enthalpy profiles from the equations derived here conclusions regarding the effect of pressure gradient mach number and wall temperature on the boundary layer characteristics are derived and illustrated in particular the effects on skin friction heat transfer coefficient separation point in an adverse pressure gradient and stability of the laminar boundary layer are analyzed
CRAN	the buckling of a square panel under shear when one pair of opposite edges is clamped and the other pair is simply supported the buckling of a square panel under shear when one pair of opposite edges is clamped and the other pair is simply supported reasons for investigation   for an efficient design of spar with thin sheet web it is important to know the load which will just cause the web to buckle as stiffeners divide the web into panels it is required to find the buckling stress of rectangular panels bounded on two sides by spar flanges and on the other two sides by stiffeners boundary conditions which represent closely this type of edge fixing are clamping along the flanges and simple support critical shear stress for a square panel held in this way conclusions and further development   it is found that the value of the critical shear stress is almost midway between its values when all four edges are clamped and all four edges are simply supported the method of solution developed in this report is of very general application and can be used to investigate the stability of rectangular panels when the loading is any combination of shear and compression or tension and the edges are clamped or simply supported and not necessarily all clamped or all simply supported by an easy extension the method of solution can also be used to find the periods of transverse vibration of rectangular panels for the same types of loading and edge fixing
CRAN	a process for the step by step integration of differential equations in an automatic digital computing machine a process for the step by step integration of differential equations in an automatic digital computing machine it is advantageous in automatic computers to employ methods of integration which do not require preceding function values to be known from a general theory given by kutta one such process is chosen giving fourth order accuracy and requiring the minimum number of storage registers it is developed into a form which gives the highest attainable accuracy and can be carried out by comparatively few instructions the errors are studied and a simple example is given
CRAN	numerical construction of detached shock waves numerical construction of detached shock waves this article proposes a new method for solving the problem of the detached shock wave if the shock wave is assumed known a cauchy problem for a system of partial differential equations arises this has been solved by several authors in the region where the system is elliptic near the peak of the shock wave considering the plane stationary case the author seeks an analytic continuation of the propagation function x y in the complex plane y y1 y2 x real in the plane x y2 the propagation function satisfies a hyperbolic equation near the peak of the shock wave a new cauchy problem is solved and the solution of the original problem obtained by analytic continuation a numerical example is treated with many details
CRAN	on the numerical calculation of detached bow shock waves in hypersonic flow on the numerical calculation of detached bow shock waves in hypersonic flow a method is described for calculating examples of hypersonic flow with a detached bow shock wave past a bluff axially symmetric body the form of the shock wave is assumed and the analysis is based on a cauchy problem for the stream function in the subsonic region where the motion is governed by a partial differential equation of elliptic type through analytic continuation into the complex domain the cauchy problem is reformulated in such a manner that it becomes properly set in the subsonic region this leads to a stable scheme for computation of the flow by finite differences numerical examples at freestream mach number 5 8 are presented in which the flow is determined throughout the subsonic region and in particular the detachment distance the location of the sonic line and the pressure distribution along the body are calculated these results are in excellent agreement with experimental data obtained at the california institute of technology
CRAN	shock wave and flow field development in hypersonic re entry shock wave and flow field development in hypersonic re entry a study is made of when and how a shock wave and continuum type flow field develop in the nose region of a highly cooled blunt body re  entering the atmosphere at hypersonic speed and in a free molecular flow regime the various types of flow regimes encountered down to low altitude conditions are delineated and the nature of the flow field and behavior of some of the aerodynamic characteristics are discussed it is shown that for a highly cooled body free molecule flow conditions occur at a higher altitude than previously indicated based on available evidence it is suggested that kinetic theory solutions which are essentially modified free molecule results along with the navier stokes equations with no surface slip serve to define all of the flow regimes except for a narrow transitional layer regime which has a height of less than one factor of 10 in free stream density change it is also suggested that the appearance of a definable shock wave occurs very rapidly in terms of density change near the beginning of the transitional layer regime and that its location as in continuum flow is governed principally by the body geometry whereas its thickness is determined by a local mean free path
CRAN	the solution of small displacement stability or vibration problems concerning a flat rectangular panel when the edges are either clamped or simply supported the solution of small displacement stability or vibration problems concerning a flat rectangular panel when the edges are either clamped or simply supported this report describes an energy method for the exact solution of problems concerning the small displacements stability or vibration of a flat rectangular panel when the edges are either clamped or simply supported the influence of stiffeners which are parallel to one pair of edges and situated in pairs on opposite sides of the panel so that the neutral axis of each stiffener pair lies in the middle surface of the panel is taken into account the method is not only applicable to isotropic panels but also to aeolotropic panels when the material of the panel has two directions of elastic symmetry parallel to the edges the final solution of the problems depends on an infinite set of linear equations for small displacement problems or on an infinite determinantal equation for stability and vibration problems the important feature of the analysis given is that it enables a direct approach to be made to these equations in any particular problem it is not in general possible to obtain a direct solution of the final equations and it is necessary to approximate and consider a finite set of linear equations or a finite determinantal equation derived from the more important terms in the analytical expression for the transverse displacement of the panel here physical intuition and if available experimental data serve as a guide and the accuracy of the final results so obtained is gauged by the rate of convergence with the increase in the number of terms considered the general method of solution is applied first to the free vibration of a square panel when all the edges are clamped and second to the buckling of a square panel under shear when three edges are clamped and one edge is simply supported
CRAN	heat transfer near the forward stagnation point of a body of revolution heat transfer near the forward stagnation point of a body of revolution in order to determine the temperature distribution over a body moving through the atmosphere a knowledge of the local heat transfer coefficients is required for slender sharp nosed bodies the heat transfer coefficients are frequently approximated by using the comparable flat plate values however for blunt nosed bodies flat plate solutions are not applicable near the forward stagnation point since the greatest rate of heat transfer may occur at the forward stagnation point its value should be investigated in this note a theoretical solution is given for the heat transfer near the forward stagnation point of a body of revolution assuming laminar incompressible low speed flow the comparable solution for two dimensional flow has been given by squire in the case of a blunt nosed body moving with supersonic velocity the flow behind the central portion of the bow wave is subsonic and it is possible that a low speed solution using as free stream conditions those behind the center of the bow wave will apply near the stagnation point
CRAN	stagnation point heat transfer measurements in hypersonic low density flow stagnation point heat transfer measurements in hypersonic low density flow in hypersonic low reynolds number flow around a blunt body the boundary layer thickness approaches the shock layer thickness shock standoff distance within the region of continuum flow in this instance the customary boundary layer approximations no longer apply hoshizaki and probstein have obtained solutions to the incompressible navier stokes equations in the stagnation region of a blunt body in this hypersonic low reynolds number flow the results indicate that heat transfer rates are substantially higher than those predicted by incompressible boundary layer theory probstein indicated that the actual heat transfer rates would be correspondingly higher than the predictions of fay and riddell these findings are of particular importance in the atmospheric entry phase of recoverable satellites
CRAN	low density stagnation point heat transfer measurements in the hypersonic shock tunnel low density stagnation point heat transfer measurements in the hypersonic shock tunnel presents absolute heat transfer measurements using resistance thermometer for hemisphere cylinder at mach numbers 9 2 to 11 2 results show vorticity interaction and viscous layer effects increase heat transfer above values predicted by boundary layer theory data are correlated using chengs reynolds number  dependent parameter investigation covers vorticity interaction to incipient merged layer regimes free stream unit reynolds numbers
CRAN	shear buckling of clamped and simply supported infinitely long plates reinforced by transverse stiffeners shear buckling of clamped and simply supported infinitely long plates reinforced by transverse stiffeners the paper presents a solution to the buckling of infinitely long plates clamped along the edges together with an extension of the solution obtained by stein and fralich for the case when the edges are simply supported it is shown that as a consequence of increasing the edge support from that of a simple support to one in which both deflection and rotation are prevented the rigidity which an intermediate transverse stiffener must possess in order to support the plate effectively is much reduced agreement between the theoretical relationships and existing experimental data is good
CRAN	critical shear stress of an infinitely long simply supported plate with transverse stiffeners critical shear stress of an infinitely long simply supported plate with transverse stiffeners a theoretical solution is given for the critical shear stress of an infinitely long simply supported flat plate with identical equally spaced transverse stiffeners of zero torsional stiffness results are obtained by means of the lagrangian multiplier method and are presented in the form of design charts experimental results are included and are found to be in good agreement with the theoretical results
CRAN	stability of rectangular plates under shear and bending forces stability of rectangular plates under shear and bending forces the author first discusses the problem of a plane simply supported rectangular plate loaded by shearing forces in the plane of the plate on all four edges there are two stiffeners attached one third and two thirds of the way along the plate the critical load is calculated for various stiffener rigidities also the rigidity necessary to keep the stiffeners straight when the plate buckles is found this stiffener rigidity is found to be slightly larger than that necessary for a plate with one stiffener and the same panel dimensions as the plate with two stiffeners the second problem discussed by the author is that of a plane simply supported rectangular plate loaded by uniformly distributed edge shearing forces in the plane of the plate and linearly distributed tension and compression in the plane of the plate at the ends the end forces vary from tension at one corner to at the other corner so that their resultant is a bending moment the presence of the edge shearing forces is found to diminish the critical bending stress in this case calculations are made for various magnitudes of bending and shearing forces for plates of various proportions
CRAN	buckling of transverse stiffened plates under shear buckling of transverse stiffened plates under shear this paper presents an analysis of buckling of simply supported rectangular plates reinforced by any number of transverse stiffeners and subjected to shearing forces uniformly distributed along the edges two cases are considered a the case of a plate with a finite length ing stresses in both cases are expressed in similar forms that is in equation 13 and k in equation 24 respectively design curves are drawn as shown in figs 2 3 and 5
CRAN	the buckling shear stress of simply supported infinitely long plates with transverse stiffeners the buckling shear stress of simply supported infinitely long plates with transverse stiffeners this report is an extension of previous theoretical investigations of the elastic buckling in shear of flat plates reinforced by transverse stiffeners the plates are treated as infinitely long and simply supported along the long sides stiffeners are spaced at regular intervals dividing the plate into a number of panels of uniform size the effect ob bending and torsional stiffnesses of the stiffener upon the buckling shear stress is calculated for the complete range of stiffnesses for panels with ratios of width to stiffener spacing of graphical forms
CISI	18 editions of the dewey decimal classifications the present study is a history of the dewey decimal classification the first edition of the ddc was published in 1876 the eighteenth edition in 1971 and future editions will continue to appear as needed in spite of the ddcs long and healthy life however its full story has never been told there have been biographies of dewey that briefly describe his system but this is the first attempt to provide a detailed history of the work that more than any other has spurred the growth of librarianship in this country and abroad
CISI	use made of technical libraries this report is an analysis of 6300 acts of use in 104 technical libraries in the united kingdom library use is only one aspect of the wider pattern of information use information transfer in libraries is restricted to the use of documents it takes no account of documents used outside the library still less of information transferred orally from person to person the library acts as a channel in only a proportion of the situations in which information is transferred taking technical information transfer as a whole there is no doubt that this proportion is not the major one there are users of technical information   particularly in technology rather than science   who visit libraries rarely if at all relying on desk collections of handbooks current periodicals and personal contact with their colleagues and with people in other organizations even regular library users also receive information in other ways
CISI	two kinds of power an essay on bibliographic control the relationships between the organization and control of writings and the organization and control of knowledge and information will inevitably enter our story for writings contain along with much else a great deal of mankinds stock of knowledge and information bibliographical control is a form of power and if knowledge itself is a form of power as the familiar slogan claims bibliographical control is in a certain sense power over power power to obtain the knowledge recorded in written form as writings are not simply and not in any simple way storehouses of knowledge we cannot satisfactorily discuss bibliographical control as simply control over the knowledge and information contained in writings
CISI	systems analysis of a university library final report and research project the establishment of nine new universities in the 1960s provoked a highly stimulating re examination of the nature purpose and management of academic libraries long established attitudes and methods were questioned but although changes were made the basic difficulty remained   a lack of objective information about the best ways of providing a library service in a university the report of the ugc committee on libraries the parry repot 267 which in general endorsed these changes also stressed the need for research into all aspects of academic library provision
CISI	a library management game a report on a research project although the use of games in professional education has become widespread only during the last decade the method has been used in a number of fields for many hundreds of years its origins have been traced to simple war games used in military training when the real thing was either unavailable or too dangerous in more recent times these games have become more and more sophisticated and many now use large electronic computers to handle the complex calculations involved since 1956 when the first well developed management game was introduced the technique has spread rapidly into a wide variety of disciplines and today it is used at all levels of education from primary school classes to courses for experienced professional men and women one of the main causes of this game explosion has been the rapid development of sophisticated management techniques such as simulation and mathematical modelling which have been made possible by rapid advances in computer technology
CISI	abstracting concepts and methods graduate library school study of abstracting should be more than a how to do it course it should include general material on the characteristcs and types of abstracts the historical development of abstracting publications the abstract publishing industry especially in the united states and the need for standards in the preparation and evaluation of the product these topics we call concepts the text includes a methods section containing instructions for writing various types of abstracts and for editing and preparing abstracting publications these detailed instructions are supplemented by examples and exercises in the appendix there is a brief discussion of indexing of abstract publications research on automation has been treated extensively in this work for we believe that the topic deserves greater emphasis than it has received in the past computer use is becoming increasingly important in all aspects of librarianship much research effort has been expended on the preparation and evaluation of computer prepared abstracts and extracts students librarians and abstractors will benefit from knowing about this research and understanding how computer programs were researched to analyze text select key sentences and prepare extracts and abstracts the benefits of this research are discussed abstracting is a key segment of the information industry opportunities are available for both full time professionals and part time or volunteer workers many librarians find such activities pleasant and rewarding for they know they are contributing to the more effective use of stored information one chapter is devoted to career opportunities for abstractors
CISI	academic library buildings a guide to architectural issues and solutions this book attempts to present representative examples of successful architectural solutions to the important problems librarians and architects face in planning new college and university library buildings or in remodeling and enlarging existing structures it does not attempt to make case study evaluations as was done by ellsworth mason for brown and yale nor does it present examples of unsuccessful solutions except to show how to avoid mistakes and in these cases the libraries will not be identified
CISI	the academic library essays in honor of guy r lyle as important for staff members individual development as was the apprenticeship in administration perhaps the most significant attitude one acquired while working for guy was engendered by his insistence that librarians must be interested in and knowledgeable about the content of the materials with which they dealt his love of literature his respect for scholarship his admiration for good writing and reading were manifested in many ways but most notably in his admonition that though we were primarily a research library we must constantly keep in mind our obligation to collect contemporary poetry fiction and belles letters it was primarily up to the library staff he felt to be responsible for these as well as for general books which crossed disciplinary lines or fell between the disciplines those books which a faculty mostly concerned with research materials is apt to overlook and in building this portion of the collection there is no substitute for a thorough acquaintance with books through a reading of critical reviews and the books themselves this counsel is from the president the professor and the college library but the importance of its thrust  the need to keep up with the world of books and publishing  was continually impressed upon us
CISI	access to libraries in college this study assumed that an additional use study held less promise than an analytical consideration of concepts the basic approach was a survey comparing traditional and current professional ideas on direct access principal data gathering instruments were documentary analysis and opinion questionnaire findings of the documentary analysis included the following research from 1890 to 1970 on the direct shelf approach and browsing left the problems largely unresolved and evidently resistant to established methods of use and user research the need for an exhaustive study of concepts was confirmed open shelf libraries  organized through shelf classification and relative location  were meant to arouse the intellectual social and political interest of the average citizen and affect his democratic self realization definitions of browsing varied greatly self indulgence by the untutored in objectionable works beneficial self education for the general reader valuable guidance for the scholar in his research
CISI	access to periodical resources the purpose of this study was to develop evaluate and recommend a national plan for improving access to periodical resources about 48 percent of all academic interlibrary loans are for periodical materials with the bulk of the loans being satisfied in the form of photocopies a major consideration in the long range improvement of the interlibrary loan system is the possible augmentation with a national system for acquiring storing and satisfying loan requests for periodical materials this study focused on the physical access to the periodical literature based on the needs of the library community design features were developed and included the following service should be made available to all users without any restriction other than access through a library initially the service should be confined primarily to rapid dependable delivery of photocopies of journal articles the collection of a center should be comprehensive in subject coverage excluding only medicine all worthwhile journals should be collected irrespective of language
CISI	the acquisition of library materials the scope of acquisitions work outlined in the introduction acknowledges the importance of selection policy serials recording and other topics kindred to acquisitions these topics are discussed in this book only as they relate to obtaining library materials they are examined thoroughly in books and papers that are cited in the references and the bibliographic note centralized acquisitions and automation of order routines are of major importance in order work and they are reviewed as chapters in this book these chapters are introductions to the concepts and problems of centralization and automation not manuals of practice for treatment of these topics in particular and in depth the reader is referred to the references cited for automation these references are only a modest selection from an enormous literature
CISI	acquisition from the 3rd world the ligue des bibliotheques europeennes de recherche liber was set up in 1971 as an international non governmental organization with the aim of establishing close collaboration between the general research libraries of western europe particularly national and university libraries and in particular to help in finding practical ways of improving the quality of the services these libraries provide at the second meeting of its general assembly held in luxembourg in 1972 liber decided to hold a seminar on the acquisition of materials from the third world and i was charged with the intellectual organization of this seminar the purpose of the meeting would be to examine the problems of acquisition the availability of materials in european libraries both for reference and for lending and the feasibility of setting up a european centre for the collection of such material to be available for loan the provision of bibliographic information preferable in machine readable form was to be a basic consideration whatever means were proposed for acquiring publications from those areas the council of europe made a generous grant towards the cost of the seminar which was held at the university of sussex from 17 to 19 september 1973
CISI	ad695049 i am not nor have i ever pretended to be an expert on microfiche nevertheless when i was invited to address the third annual northeastern ddc industry users conference in waltham massachusetts in april of 1968 i had the temerity to attempt to describe what i as a user would like to have in a fiche reader towards a uniform federal report numbering system and a cuddly microfiche reader  two modest proposals revised september 1968 ad 669204
CISI	the administration of the college library if this book has a central thesis it rests upon the simple but frequently neglected principle that college library service goes beyond the commonly accepted functions of book circulation and storage the college library exists not merely to house and circulate library materials but to supplement and extend the teaching process with reference service to afford faculty members library opportunities for improving instruction and to encourage students to read more and better books administration is essentially a service activity a tool through which library functions are more fully and efficiently realized the present work retains most of the material of the first edition but includes substantial revision in each chapter the book was planned not only as a text in the teaching of college library administration but also for independent professional reading because readers have found the footnotes and chapter bibliographies useful for reference purposes they have been brought up to date and in some cases extended
CISI	information flow in research and development laboratories technical communication patterns in two research and development laboratories were examined using modified sociometric techniques the structure of technical communication networks in the two laboratories results from the interaction of both social relations and work structure the sociometric stars in the technical communication network who provide other members of the organization with information either make greater use of individuals outside the organization or read the literature more than other members of the laboratory
CISI	adopting the library of congress classification system this manual is designed to make it possible for any library to change efficiently to the library of congress classification system detailed procedures are outlined which may serve as exact models or as a series of suggested steps which have proven effective in actual use most of the text deals with the necessary criteria for effecting the planning making the preparations selecting the tools and establishing the procedures which are essential for a reclassification project beyond this considerable attention has been given to many of the problem areas of the lc classification series biography bibliography law pz3 and pz4 in addition the literature tables viiia and ixa two of the most frequently used tables throughout the entire class system have been thoroughly explained and their application illustrated by a series of comprehensive examples since the mechanics production and cost of catalogue card copy can significantly affect the flow of books to users a chapter has been devoted to describing the use of xerox copying machines in library operations finally an annotated bibliography of books and articles judged to be helpful in deciding to reclassify is included for those readers who wish to delve more deeply into the tortuous and frustrating 50 year history of the concept of centralized cataloging and classification the numbers enclosed in parentheses throughout the text refer to sources in the bibliography which relate to or support the arguments being advanced in any particular case
CISI	adventures in librarianship there has long been a need for a continuing series to provide scholarly reviews of the rapidly changing and advancing field of librarianship a series which would select subjects with particular current significance to the profession and provide an analysis of the advances made through research and practice advances in librarianship is planned and designed to fill this need it will present critical articles and surveys based on the published literature research in progress and developments in libraries of all types mechanization may appear to be the most obvious of the advancing fronts of librarianship for automation has caught the enthusiastic support of all librarians who can visualize its potential advances in this field will certainly be found in every volume of this series as the first group of articles in this volume demonstrate technological change has an obvious and direct implication for libraries but the problem has been found to be much more complex than the simple inventory problem many experts expected advances in librarianship is dedicated to presenting the realities of automation assessing where we are where we are going and how fast we can hope to get there the machine and cataloging reviews the current status of the machine produced book catalog and what lies ahead as we enter the age of marc where business methods have greater applicability progress is easier as reported in mechanization of acquisition processes even in this area generally acceptable practices and standardization are in the future not the past one of the problems of major and immediate importance in computerization of catalog information is that discussed in filing systems for computer manipulation this detailed review presents the complexity of the problems and suggests possible solutions for many years technical service costs have been defended without adequate knowledge of the facts as automated procedures are proposed standards are determining costs of traditional operations become essential the article on standards for such costs shows why the problems have been difficult and reviews the significant advances of the past few years the school library has widened its dimensions in materials and services much more rapidly than other libraries as reflected in its new name the instructional media center here technical change together with new teaching methods has made possible major developments in library service in schools as well as for children in the public library two articles make clear that what can be done has been demonstrated and that what remains is to make this the rule rather than the exception bibliotherapy is an example of a field in which progress has been slow articles which illustrate the potential which systems theory and managerial planning theory have for libraries the articles on the application of these concepts which come from research in administration are provocative and may appear controversial to some the article on library development in developing countries provides an analysis in depth of our efforts and degree of success in assisting other countries in providing the library service which is so important in the modern world
CISI	selective dissemination of information the present contribution does not duplicate previous studies but complements the earlier publications and closes the few gaps that exist in the literature prior to 1966 and after 1971 additionally it is a bold attempt to evaluate critically and objectively the history of the mechanized selective dissemination of information sdi as reflected in the literature from the initial description by luhn 1958 1961b c to the post 1970 period when the sdi boom began losing ground to the more popular on line interactive systems the review therefore questions and interprets the concept of sdi its implementation and its evolution in the light of work performed by many companies government agencies universities societies and libraries during the last fourteen years
CISI	adventures in theory of languages in trying to give an account of the statistical properties of language one is faced with the problem of having to find the common thread which would show the many and multifarious forms of language statistics   embodied in scattered papers written by linguists philosophers mathematicians engineers each using his own professional idiom as belonging to one great whole quantitative linguistics the book stresses the peculiarity of statistics of language structure as against just conventional statistics to put the difference between two types of statistics briefly the latter comprises the methods and parameters of general number statistics as applied e g in economics and demography the former has its own methods and characterising parameters particularly useful for describing and evaluating language structure the idea of statistical linguistics as using concepts and methods of its own which was adumbrated in the authors language as choice and chance 1956 has now taken definite shape of this development i shall try to give a brief account in my book language as choice and chance the foundation was laid for a truly sensible application of statistics to language by my interpretation of the langue parole dichotomy as being essentially that between statistical universe and sample
CISI	the age of jewett charles coffin jewett and american librarianship 1841 1868 most librarians mark the beginning of modern librarianship from the founding of the american library association in 1876 and the appearance on the national library scene of such dynamic and controversial figures as melvil dewey and charles ammi cutter but in doing so they overlook an extremely significant era in the history of our profession for the quarter century preceding the 1876 meeting in philadelphia was one characterized by great advances in the field of american librarianship this period of growth was to have considerable influence on the course of library development in america after 1876 to ignore the third quarter of the nineteenth century is to risk misinterpreting the pivotal post 1876 era and in this time of reappraisal it seems particularly appropriate and useful to focus our attention on the years preceding the founding of the american library association
CISI	on aggression in this book lorenz deals with the evolution of aggression in vertebrates he points out that aggressivity is totally different from predation that it is a biological necessity for defence of territory and for a cornered animal and that it becomes mixed up with other innate drives thus leading up towards reduction of intraspecific damage this be it noted is most evident in fiercer social predators like wolves where escape from the pack is virtually impossible and where co operation without fighting is necessary for survival whereas in the non social but proverbially peaceful dove prevention of escape leads to violent and often fatal attacks on the weaker mate in a final chapter he advances some suggestion as to how in the human species where evolution is primarily cultural and not guided by darwinian selection in the strict sense the aggressive drive may be canalized into less dangerous channels man has innumerable ways of adaptively ritualizing his behavior many of them analogous if not homologous to those found in animals in any event on aggression is a fascinating book by a master of his subject
CISI	education and manpower for librarians this paper is not an official policy statement of the american library association nor of the office for library education it is simply an exploration an outline of possibilities for consideration by the profession its purpose is to generate discussion that will lead eventually to a statement of association policy that the profession will support and make effective a basic assumption on which the statement rests is this that the library occupation is much broader than that segment of it which is the library profession but that the professional segment has responsibility for the definition and supervision of the training and education required by the complete range of activities encompassed by the occupation librarians are not the only persons who work in libraries but librarians are the ones who are concerned with the advancement and improvement of the library profession it follows then that it is the obligation of the professionals to engage actively in the establishment and maintenance of standards and norms governing the preparation of people who work at any level in libraries they should define and guide the kinds of preparation most useful at the pre professional level and not merely the education of those who will hold positions at the level we now call professional
CISI	pilot inventory of library holdings this project was undertaken because of the high degree of uncertainty among the library staff regarding the extent of the problem of missing books the findings of this study gave the ohio state university libraries concrete evidence as to how many books are missing and indicated the areas in which book losses are the greatest these figures also provide information which can be conveyed to the faculty or administration when they voice complaints about the unavailability of library books the areas where losses are high also tend to indicate the areas of most frequent use
CISI	libraries and technological forces affecting them 1 what do we mean by technology and what kind of technological forces are we concerned with 2 why is it important to be concerned with technology in thinking about the future of libraries 3 what kinds of technology are particularly important for libraries 4 how can this technology be applied today 5 what can we foresee for the future as we move toward the year 2000 6 what if anything should we do tomorrow to try to get from here to here
CISI	algebraic systems as far back as the 1920s algebra had been accepted as the science studying the properties of sets on which there is defined a particular system of operations however up until the forties the overwhelming majority of algebraists were investigating merely a few kinds of algebraic structures these were primarily groups rings and lattices the first general theoretical work dealing with arbitrary sets with arbitrary operations is due to g birkhoff 1935 during these same years a tarski published an important paper in which he formulated the basic principles of a theory of sets equipped with a system of relations such sets are now called models in contrast to algebra model theory made abundant use of the apparatus of mathematical logic the possibility of making fruitful use of logic not only to study universal algebras but also the more classical parts of algebra such as group theory was discovered by the author in 1936 during the next twenty five years it gradually became clear that the theory of universal algebras and model theory are very intimately related despite a certain difference in the nature of their problems and it is therefore meaningful to speak of a single theory of algebraic systems dealing with sets on which there is defined a series of operations and relations algebraic systems the formal apparatus of the theory is the language of the so called applied predicate calculus thus the theory can be considered to border on logic and algebra
CISI	indexing and abstracting by association this article discusses the possibility of exploiting the statistics of word co occurrence in text for purposes of document retrieval co occurrence is defined and related to the mental processes of authors and readers several means of quantitative measurement of word co occurrence are then scrutinized it is shown that the most strongly co occurring word pairs which are therefore associated in a statistical sense can be represented in the form of an association map the last half of the article presents two modes of use of association maps in literature searching
CISI	cost analysis and simulation procedures for the evaluation of large information systems a computer program has been written and used which simulates the several year operation of an information system and computes estimates of the expected operating costs as well as the amount of equipment and personnel required during that time period the program has been used for the analysis of several large systems and has proven itself to be a useful research tool for the study of systems with so many components and interrelated operations that an equivalent manual analysis would be extremely cumbersome and time consuming and perhaps even impractical this paper describes this program and shows as an example some of the results of a simulation of two of several suggested designs for a specific information system
CISI	a note on the pseudo mathematics of relevance recently a number of articles books and reports dealing with information systems i e document retrieval systems have advanced the doctrine that such systems are to be evaluated in terms of the degree or percentage of relevancy they provide although there seems to be little agreement on what relevance means and some doubt that it is quantifiable there is nevertheless a growing agreement that a fixed and formal relationship exists between the relevance and the recall performance of any system thus we will find in the literature both a frankly subjective notion of relevance as reported by individual users and equations curves and mathematical formulations which presumably provide numerical measures of the recall and relevance characteristics of information systems this phenomenon of shifting back and forth from an admittedly subjective and non mathematical term to equations in which the same term is given a mathematical value or a mathematical definition has its ancient parallel in discussions of probability one cannot of course legislate the meaning of a term it all depends as alice pointed out on who is master the user or the term on the other hand the use of a single term in the same document to cover two or more distinct meanings especially when such a usage is designed to secure the acceptance of a doctrine by attributing to it mathematical validity which it does not have represents a more serious situation than merely careless ambiguity
CISI	some questions concerning information need the expression satisfying a requesters information need is often used but its meaning is obscure the literature on information need in relation to retrieval suggests three different though not inconsistent possible interpretations however each of these interpretations is itself fundamentally unclear the various obscurities involved are indicated by critical questions which those who write of information need are invited to answer
CISI	vocabulary building and control techniques the rationale is given for creation and maintainance by an information center of a controlled indexing and retrieval vocabulary basic vocabulary principles are 1 use of natural language 2 development of hospitality to new concepts 3 provision of adequate cross referencing and 4 formatting for easy use terminalogical conventions necessary for development and control of a useful vocabulary are summarized and the techniques for applying these conventions to construct a thesaurus are described computerized editing techniques and updating techniques are briefly set forth
CISI	attendance and use of the science library at m i t this is an interim report on continuing studies of library operations at massachusetts institute of technology being made by members of the institutes operations research project in cooperation with the librarians and library staff in this report which is based on actual observations of on the premise use made of the science library various statistics measuring the kind degree and intensity of use are tabulated in addition there are some suggested measures of effectiveness of the library a unique outcome of the survey has been the construction and verification of a mathematical model employing probability theory to measure rate and kind of use of library material together with length of stay of library patrons such models characteristic of an operations research approach give promise of furthering the goal of effective library management and planning
CISI	information gathering patterns and creativity a study of research chemists in an industrial research laboratory a comparison of creative and noncreative research chemists with respect to the ways in which they use their professional and technical literature the creative chemists differ from the noncreative in that the former read more technical literature on the job are less reluctant to use literature of greater reading difficulty are less influenced in their independence of thought read more extensively and consult more frequently the older material are more inquisitive and have broader cultural interests the findings of the study are believed to be helpful in planning library and information services in refining future inquiries into the ways in which scientists use recorded information and in improving tests for the identification of creative ability among chemists
CISI	the half life of some scientific and technical literatures a consideration of the analogy between the half life of radioactive substances and the rate of obsolescence of scientific literature the validity of this analogy suggest the possibility of more accurate prognostications concerning the period of time during which scientific literature may by used and hence might help to guide the planning of library collections and technical information services
CISI	keyword in context index for technical literature kwic index a distinction is made between bibliographical indexes for new and past literature based on the willingness of the user to trade perfection for currency indexes giving keywords in their context are proposed as suitable for disseminating new information these can be entirely machine generated and hence kept up to date with the current literature a compatible coding scheme to identify the indexed documents is also proposed in it elements are automatically extracted from the usual identifiers of the document so that the coded identifier yields a maximum of information while remaining susceptible to normal methods of ordering
CISI	comparisons of four types of lexical indicators of content an experiment was conducted to determine which of four types of lexical indicators of content could be utilized best by subjects to determine relevant from irrelevant documents and to answer a set of 100 questions the results indicate that there were no major differences between the groups using complete text and abstracts to select relevant documents but the group utilizing the complete text obtained a significantly higher score on the examination
CISI	recorded use of books in the yale medical library explores the amount of use of books by categories of borrowers in the yale medical library with a view to discovering the proportion of the catalogue which should be put in machinable form
CISI	the worlds technical journal literature an estimate of volume origin language field indexing and abstracting a quantitative estimate is made of the magnitude of the worlds scientific and technical journal literature problem using a number of basic sources of statistical information a composite picture is established to show such things as the total volume linguistic and national origins breakdown by subject field and degree of coverage by the abstracting and indexing services
CISI	machinelike indexing by people a study of several thousand entries in a classified bibliography of article titles the index medicus revealed that a large proportion of the title entries contained words identical to or synonymous with words of the corresponding subject heading it is inferred that a major part of the bibliography studied could have been compiled by a machine procedure operating on titles alone provided the machine was supplied with a suitable synonym dictionary
CISI	bibliographic coupling between scientific papers this report describes the results of automatic processing of a large number of scientific papers according to a rigorously defined criterion of coupling the population of papers under study was ordered into groups that satisfy the stated criterion of interrelation an examination of the papers that constitute the groups shows a high degree of logical correlation
CISI	worldwide census of scientific and technical serials results of the census of the worlds scientific and technical serial literature within the limits defined and based on an examination of published source material from countries throughout the world reflect a total title population much lower than estimated before distribution of this population by country showing better than 50 of the total divided among six major countries is included and discussed together with a broad subject distribution of serials for certain countries
CISI	new factors in the evaluation of scientific literature through citation indexing more than one million citations from the scientific literature have been processed by the citation index project at the institute for scientific information the project sponsored by nsf and nih will be described briefly and new methods of using citation data for evaluation of publications will be discussed summaries of statistical data compiled by computer methods such as the following will be given 1 frequency of citation of one journal by another 2 frequency of current citations to the past literature 3 frequency of self citation by journals and authors 4 number of source citations per cited paper 5 number of references per source paper 6 number of papers published per journal
CISI	the notion of relevance analysis of the problems of defining the mutual relevancies of queries and document collections indicates that they essentially involve the problem of conceptual relatedness in order to consider the later problem the question of concept formation is first discussed which in turn requires a definition of concept an extensional interpretation is suggested whereby a concept is associated with a class of conceptually similar documents users similarity  judgments then provide the empirical data for formal definitions of concept and conceptual relatedness it is found however that certain very general difficulties rule out the possibility of defining concepts and their relatedness by the method proposed since this method is based on human relevance judgments it seems a natural one to adopt so that its collapse has serious practical and theoretical consequences an alternative approach is therefore proposed whose elaboration will form part ii of this article
CISI	the consistency of human judgments of relevance a comparison of the ability of humans to consistently judge the relevance of documents to their general interests from bases of citations abstracts keywords and total text was made under controlled experimental conditions the results showed that 1 humans are able to make such judgments consistently and 2 the consistency of the judgment is independent of the particular base from which it is made apparent inconsistency arising from judgments made on the basis of abstracts remains unexplained this experiment as well as others concerned with human evaluations of text material leave unexplored the basic problem of providing a metric scale on which such evaluations can be measured
CISI	the distribution of term usage in manipulative indexes a semi empirical correlation based on data from nine indexes permits the prediction of the percentage of terms in a manipulative index vocabulary which will be used to index any given number of documents this is a function of the total number of index entries in the system a log normal relationship similar to zipfs law exists between total index entries and distribution of term usage based upon the correlation optimum vocabulary size and growth rate can inferred as well as the most efficient arrangement of index entries in a storage medium the results agree well with published data and appear to be particularly useful for designers of mechanized retrieval or publication operations
CISI	measuring the reliability of subject classification by men and machines procedures for measuring the consistency of document classification are described three subject specialists classified 997 abstracts of psychological reports into one of eleven categories these abstracts were also mechanically classified by a computer program using a factor score computational procedure each abstract was scored for all categories and assigned to the one with the highest score the three manual classifications were compared with each other and with the mechanical classifications and a series of contingency coefficients was computed the average reliability of manual classification procedures was equal to 870 the correlation between automatic and manual classification was 766
CISI	a quantitative measure of user circulation requirements and its possible effect on stack thinning and multiple copy determination the strategy outlined in this article describes a possible aid to the librarian for thinning a librarys stack according to the criterion of user needs the method uses the last circulation date as a parameter of user circulation requirements the resulting stack collection would by design satisfy over 99 percent of the user circulation requirements and yet be of minimum size preliminary but not yet fully validated research indicates that the number of volumes in a librarys holdings may be reduced by 60 to 70 percent and yet satisfy well over 99 percent of the user requirements it may also be possible to determine which books should have multiple copies in order that user disappointment can be minimized the effective result of this approach is that there now may be a quantitative method of maintaining the librarys holdings at a reasonable level and in addition a reduction in the disappointment of the user who is unable to find the book he wants because of use by another
CISI	improvement of the selectivity of citation indexes to science literature through inclusion of citation relationship indicators citation indexes to large bodies of science literature can often list far more citing references under the known cited reference than the user can afford the time to look up by providing some additional information beyond the minimal association of the citing reference with the cited reference a citation index could provide the means of the user to select from a long list those citing references which are most relevant to his immediate search requirement means of providing this selectivity are discussed particular attention is given to the possibility of adding short codes to the citation entries which would be informative of the way in which the citing publication is operationally related to the cited one this method is an integral feature of the shepards legal citations a scheme of citation relationships of potential value to users of science literature is presented these relationships were tested on a sampling of physics literature the suggested categories include indicators of the relation of the citing reference to the scientific process in general as well as indicators of its relationship to the cited reference in particular assignment of the categories to a citation requires the exercise of judgment as in subject indexing but does not involve the use of subject terminology an illustration is provided of the application from a citation index to physics literature
CISI	the norms of citation behavior prolegomena to the footnote the publication explosion has focused renewed attention on the lowly footnote while we are all at least partially aware of the technical functions of the citation for both the writer and the reader of the scientific paper little is known about the norms operating in actual practice even less is known about the operating norms with respect to the more sociological functions including the acknowledgement of intellectual debts or the conferral of recognition upon the works of others this paper reviews the state of our knowledge raises questions and proposes suggestions and hypotheses for studying the relationships between footnoting practices among scientists and the social system of science
CISI	adaptive information dissemination computer dissemination of information offers significant advantages over manual dissemination because the computer can use strategies that are impractical and in some cases impossible for a human this paper describes the ames laboratory selective dissemination of information system with emphasis on the effectiveness of user feedback the system will accept any document abstract keyword etc in a kwic or science citation index source format user profiles consist of words or word clusters each with an initially assigned significance value these values are used in making the decision to notify a user that he may be interested in a particular document according to responses the significance values are increased or decreased and quickly attain an equilibrium which accurately describes the users interests the system is economical compared to other existing sdi systems and human intervention is negligible except for adding and deleting profile entries
CISI	comparison of the results of bibliographic coupling and analytic subject indexing a detailed comparison of how 334 papers in volume 112 of physical review form related groups according to two criteria of relatedness the criteria are 1 the analytic subject index as used by the editors of the physical review and 2 the method of bibliographic coupling the similarities and differences between the groups thus formed are illustrated and discussed
CISI	an experiment in automatic indexing this report describes a method of indexing documents which is based on the assumptions 1 that a subset of the words in a document can be an effective index to that document and 2 that this subject can be approximated by selecting those words from the document whose frequencies are statistically unexpectedly high the results of the experiment are encouraging although not definitive because any index set chosen must be tested by using it for retrieval from a large collection
CISI	comparative indexing terms supplied by biomedical authors and by document titles the original aim of this study was to obtain objective data bearing on the much argued question of whether author indexing is good author indexing of 285 documents reporting biomedical research was scored by comparing the author  supplied terms author set for each paper with a criterion set of terms that was established by asking a group of 12 potential users to describe the same document terms in the document title title set were scored similarly the average author set contained almost half of all the terms employed by more than one member of the user group and scored 73 of the maximal possible score as compared with 44 for the average title set when judged by the method and criterion employed here author indexing is substantially better than indexing derived from document titles the findings suggest that indicia supplied by an author should serve scientists in biomedical disciplines other than his own about as well as they serve his disciplinary colleagues the general method developed for measuring indexing quality may represent a practical yardstick of wide applicability
CISI	the kwic index concept a retrospective view this paper defines and describes the kwic keyword in context index concept providing a history of the concept and of its literature it discusses variations of the index such as the bell telephone index kwoc indexes and the wadex the paper discusses improvements and variations to the kwic index such as manipulation of the index line variations of the code addition of classification information combination of author index and title index and improvements to the preparation of the kwic indexes such as improvement of titles and use of a thesaurus and discusses improvement of the use of the kwic index the paper discusses the usage of the kwic index and comments on the future of kwic indexes of the kwic concept
CISI	simulation of boolean logic constraints through the use of term weights the evolution described below of one aspect of the nasa system and technical information facilitys machine search system may be of general interest to the documentation profession
CISI	bradfords law and the keenan atherton data bradfords methods are applied to the keenan atherton data the results do not fit bradfords law
CISI	computer produced micro library catalog the philosophy production and cost effectiveness of a computer generated library catalog is described this catalog is unique in that it utilizes direct computer to microfilm composition techniques employing the stromberg carlson 4020 cost user acceptance and by product capabilities are stressed
CISI	distribution of indexing terms for maximum efficiency of information transmission a function was developed for the optimum distribution of indexing terms by the number of postings this makes it possible to transmit information with maximum efficiency the comparison of the actual distribution of the term groups with the calculated optimum distribution provides an objective measure for evaluating any indexing system with respect to its efficiency as information transmission channel
CISI	relevance disagreements and unclear request forms disagreements about the relevance of documents to retrieval requests occur because relevance judges differently interpret requests of documents requests may be differently interpreted because they are unclear well known types of request obscurity are reviewed less well known is that a request may be unclear because its form   documents about subject s document answering question q etc   is unclear explications are developed of the meanings of the request forms just given and several others a request of any of the forms discussed is interpreted to be for documents which support statements of a specified kind in a specified way examples are given which suggest that some perhaps all about s requests are unclear some ways of formulating clear question requests are given various ways in which documents may support statements are distinguished these depend on on such factors as parts of a document use inference strength and background knowledge permitted some possible clear support specifications are indicated
CISI	opinion paper although a large number of selective dissemination of information sdi systems have been planned implemented and tested over the past few years insufficient attention has been given to the collection and interpretation of important data needed for evaluation we describe some of the defects common to almost all of the reported systems single out one recent report for detailed discussion and argue in favor of collection and correct interpretation of data on one important and frequently overlooked evaluation factor
CISI	information science what is it in seeking a new sense of identity we ask in this article the question what is information science what does the information science do tentative answers to these questions are given in the hope of simulating discussion that will help clarify the nature of our field and our work
CISI	expected search length a single measure of retrieval effectiveness based on the work ordering action of retrieval systems a measure of document retrieval system performance called the expected search length reduction factor is defined and compared with indicators such as precision and recall that have been suggested by other workers the new measure is based on calculations of the expected number of irrelevant documents in the collection which would have to be searched through before the desired number of relevant documents could be found its advantages are 1 it provides a single index of the property it attempts to measure 2 it allows for gradations of retrieval status through the mathematical concept of a weak ordering 3 it evaluates retrieval performance relative to random searching and 4 it takes into account the amount of relevant material desired by the requester
CISI	a literature search and file organization model a principle of sequential optimization in search theory distributes the search effort at each stage so as to maximize the probability of target detection with the effort expended thus far as an application of this principle to the search of pertinent items in a literature file the file items should be arranged in decreasing order of the probability that an item will yield the information sought complete ordering in this manner may not be feasible and it is proposed that the files be partially ordered in search zones with some loss in search efficiency a model for assessing the relative efficiency for partial ordering is developed and used to determine optimal zone sizes under an assumed target distribution pattern in this way trade off between file organization effort and search effort can be meaningfully evaluated a representative target distribution function for search literature appears to follow the bradford law of scattering this function is used to demonstrate the application of the model over a meaningful range of parameters obtained from empirical studies it is shown that a good two zone search plan to scientific literature is one in which 15 20 of the most useful documents are examined first only about one of three searches should have to go on to a search over the remainder of the file
CISI	the publication inflation the much vaunted information explosion seems to be the manifestation of a rather generalized publication inflation multipublication and pretentious writing have become obstacles to communication between human minds to counteract their harmful effects it will be necessary to reduce the quantity and improve the quality of the printed records by filtering the material before it is stored for retrieval
CISI	a computer based serials control system for a large biomedical library rather than reiterate the obvious purposes and procedures involved in creating a computer system for control of serials in this paper the author deals with the concept upon which the ucla system is based and the manner in which the system is maintained in day to day operations of the ucla biomedical library the paper deals with some of the points made in an earlier publication from the ucla serials project the attempt is to show how the theory of publication pattern discussed in the earlier article has been used to produce a different idea in computer control of serials publication pattern information which is entered into the master record for each title causes check in cards for the next expected issue of each title to be generated by the computer regardless of when this text issue is expected   next week next month next year this is departure from most systems which attempt to predict a certain number of issues which should arrive during a given time period the information which must be a part of the computer record is described as are library procedures in maintaining the system
CISI	a study of searching the eye research literature the paper is a report of most of the major findings of a study in searching the periodical eye research literature questions were collected from eye researchers and a selected group of these were searched in nine different secondary sources articles thought to be relevant were xeroxed and sent to the eye researchers who subsequently rated the articles articles of eye research interest are found in a wide variety of journals but a small number of journals carry a large proportion of the articles judged valuable by the eye researchers approximately a fourth of eye research articles are in foreign languages translations are not readily available despite a delay of more than 15 month between the original appearance of article in journals and the mailing of photocopies about half of the articles of interest to the researchers were not known to them previously for extensive retrospective searches more than one secondary service must be used index medicus and excerpta medica section 12 or ophthalmic literature would be good sources medlars demand searches were not shown to be clearly superior to manual searches of index medicus titles abstracts and full text were shown to be equally effective in permitting searches to retrieve references that were subsequently rated as relevant by the researchers a searcher with a background in ophthalmology was able to retrieve more articles of research interest than other non ophthalmologist searchers
CISI	psychology and information an aspect of the human use of information that has generally been overlooked in the automation in information services is the human tendency to locate information spatially computer based systems do not necessarily assign any unique role to spatial tags and so a feature of considerable importance for the organization of the users memory seems to have been largely overlooked the spatial dimension of human memory is discussed and some suggestions are offered for exploiting it more effectively in the context of information retrieval services
CISI	the use of simulation in studying information storage and retrieval systems previous applications of simulation to information storage and retrieval systems isrs have been overly restrictive in their scope and have failed to consider the environment within which such systems operate this paper considers the isrs as a subsystem within a larger system which includes the users and the funders of the retrieval system the three components form a closed loop information feedback system in which user response influences both the funding and operation of the isrs as it attempts to satisfy user needs within a finite budget allocation reward cost theory provides the basis for describing user behavior an industrial dynamics model has been developed to simulate isrs user funder behavior where a university departmental library is the isrs component the results which such an analysis can produce are discussed
CISI	retrieval of answer providing documents i better understanding of subject document retrieval might result if different functions of subject document retrieval system are studied separately this paper is concerned with retrieval of documents in response to a question from which answers to that question can be inferred answer providing documents answer can be inferred from document has many possible meanings one of which must be selected an inference specification inasmuch as scientists in a field disagree about the correctness of inferences have somewhat different background knowledge etc any inference specification can only approximate scientific inference practices two sources of systematic knowledge of document statement inference practices in a scientific field are described ii if a content word occurs in a question then it occurs in any answer to that question with some apparently tractable exceptions an indexing procedure based on that fact is described which would permit retrieval of all answer providing documents for a question however because the indexing is nonrelational it could cause false retrievals as well various ways of dealing with such false retrievals are briefly indicated and a study is sketched that would provide data for helping selection among them two special point concerning indexing for retrieval of answer providing documents are discussed separately
CISI	statistical generation of a technical vocabulary the results of an experiment in the use of statistical techniques for extracting a technical vocabulary from document texts are presented and discussed
CISI	on understanding user choices textual correlates of relevance judgements an empirical investigation of the role of documents in relevance judgements is reported abstracts previously judged relevant partially relevant and nonrelevant to each of 61 questions were compared to see whether textual differences could be found which might reasonably account for the rating differences the results of this comparison were fairly clear cut characterizations in each case of relevant and partially relevant abstracts these characterizations were found to be expressible largely as meaningful co occurrences of terms closely related to the question it is suggested that the textual bases of user choices may be more understandable than has been supposed
CISI	word word associations in document retrieval systems the smart automatic document retrieval system is used to study association procedures for automatic content analysis the effect of word frequency and other parameters on the association process is investigated through examination of related pairs and through retrieval experiments associated pairs of words usually reflect localized word meanings and true synonyms cannot readily be found from first or second order relationships in our document collections there is little overlap between word relationships found through associations and those used in thesaurus construction and the effects of word associations and a thesaurus in retrieval are independent the use of associations in retrieval experiments improves not only recall by permitting new matches between requests and documents but also precision by reinforcing existing matches in our experiments the precision effect is responsible for most of the improvement possible with associations a properly constructed thesaurus however offers better performance than statistical association methods
CISI	a comparison between manual and automatic indexing methods the effectiveness of conventional document indexing is compared with that achievable by fully automatic text processing methods evaluation results are given for a comparison between the medlars search system used at the national library of medicine and the experimental smart system and conclusions are reached concerning the design of future automatic information systems
CISI	effectiveness of information retrieval methods results of some 50 different retrieval methods applied in three experimental retrieval systems were subjected to the analysis suggested by statistical decision theory the analysis validates a previously proposed measure of effectiveness and demonstrates its several desirable properties the examination of a wide range of data in relation to this one metric provides a clear and general assessment of the current state of the retrieval art
CISI	managerial cost accounting for a technical information center the purpose of this paper is to describe a research project conducted at a technical center to test the hypothesis that a theoretically sound managerial cost accounting system can be designed to meet the specific characteristics of a technical information center by revising and innovating systems utilized by other enterprises a computerized cost system was developed and operated for a three month period to test this hypothesis the results of the study indicate that effective managerial cost accounting is possible for a technical information center relevant cost information was generated periodically to measure the operating performance of the centers production process a summary of the data that were reported regularly to management is presented in this paper
CISI	medlars report on the evaluation of its operating efficiency a comprehensive program to evaluate the performance of medlars was conducted by the national library of medicine in 1966 and 1967 this report describes the methodology used and presents a summary of the principal results conclusions and recommendations
CISI	biomedical literature analysis of journal articles collected by a radiation  and cell biologist the authors journal reference cards for 1965 and 1966 were analyzed according to three interest patterns i the total collection of 1469 article titles a potentially useful set ii a subset concerning only his research speciality and iii a subset of articles defined as useful for each pattern journals were ranked by frequency of use and a scatter diagram was drawn patterns i and ii largely resembled patterns obtained by counting citations in basic journals or by counting publications of selected researchers pattern iii was more widely scattered it is concluded that access to diverse journals is needed by researchers to supply new ideas and that this diversity of reading is not reflected adequately by citation counting or other indirect means current contents used by the author for current awareness purposes in building his card file generated 88 of all articles scatter diagrams indicated the decreased scatter predicted from its use the 30 most important journals in this collection including about 80 of titles are ranked for each pattern
CISI	the effectiveness of automatically generated weights and links in mechanical indexing work concerned with the statistical evaluation of the output of the medico automatic indexing method is described the statistical test were designed primarily to examine the validity of the assumptions which formed the basis of the algorithms developed for the automatic computation of weights and for the automatic generation of links between index terms and modifiers this evaluation also includes a comparison of the output generated from full text and from the processing of the abstracts or summaries of the same articles
CISI	on line access to information nsf as an aid to the indexer cataloger when adding a document to a collection an indexer should choose a representation which makes evident both the content of the document and its relation to other documents already in the collection toward this end the negotiated search facility nsf makes possible indexer controlled retrieval of information from a collection data base using tools beyond those available in a traditional bibliographic catalog the design philosophy of nsf is to offer a framework to guide the indexer while allowing him freedom to retrieve any data which he judges will help him make indexing decisions an example which indicates how an indexer might use the facility also shows how the display formats and command language promote interaction while the discussion is directed toward indexing it should be clear that the facility would be equally useful to the searcher
CISI	computer selection of keywords using word frequency analysis a statistically based method for automatically identifying keywords in machine readable text has been developed which produces keyword lists that agree better with composite lists produced by panels of human indexers than do lists produced by five statistical criteria previously suggested and also better than lists produced by most of the individual panel members the method makes use of both the in document word occurrence frequency and the in corpus relative occurrence frequency as measures of word importance each statistical criterion was compared with the performance of human indexers by the use of rank correlation statistics the simple word count was found to be superior to the other four previously suggested criteria   all of which made use of the in corpus relative occurrence frequency the test were conducted over 19 documents dealing with the subject of information science a total of over 66 000 word occurrences seventeen indexers representing eight different information centers participated in experiments
CISI	a graphic catalog card index to improve accessibility and maintenance of art slides in the united states military academy library at west point a model card with a graphic image of the slide was designed with pertinent identifying information displayed directly above a black and white opaque photo and also key punched into it the card serves for ample comparison reference previous to handling the slides and can produce a subject arranged permuted index in book form the later permits access from the approach of form geographic area name time of origin artist school or style etc some added advantages common to other kinds of graphic collections are detailed estimated costs of photo reproduction of original cards various kinds of copies and computer time and materials are listed future benefits from a consistent unified cataloging system for graphic objects and the dissemination of this kind of information in a network structure are indicated as major goals
CISI	indexing consistency and quality a measure of indexing consistency is developed based on the concept of fuzzy sets it assigns a higher consistency value if indexers agree on the more important terms measures of the quality of an indexers work and exhaustivity of indexing are also proposed experimental data on indexing consistency is presented for certain categories of indexers and consistency quality and exhaustivity values are compared and analyzed the analysis of indexing exhaustivity leads to the conclusion that the increase of information as a result of group indexing is a process analogous to bradfords law of information scattering lotkas law of scientific productivity and zipfs law of vocabulary distribution
CISI	is interindexer consistency a hobgoblin it is often assumed that the amount of interindexer consistency experienced under a given method of indexing is somehow indicative of the quality of the indexing to explore this assumption two hypotheses are stated concerning the possible connection between interindexer consistency and indexing quality a specific counter example is then exhibited which shows both hypotheses to be invalid although a mathematical analysis of the counterexample yields certain insights the general relationship between interindexer consistency and successful retrieval is more subtle than might have been expected it is concluded that until equations describing this relationship have been derived measurements of inter indexer consistency will have little meaning as clues to indexing quality
CISI	the cost analysis of document surrogation a literature review a state of the art literature review on the cost of classification cataloging indexing and abstracting has been included it was found that while some data on specific costs are available the literature is generally found lacking from the point of view of accuracy completeness consistency and availability
CISI	some independent agreements and resolved disagreements about answer providing documents eighty two documents and 30 questions in documentation and related areas was compared to find answer providing documents documents from which answers to questions can be inferred two judges documentation experts made comparisons independently they discussed their disagreements attempting to resolve them in each case the positive judge was first asked to indicate what answer he inferred and from what document passage s the further discussion depended on the details of each case in general the resolution procedures used will resolve a disagreement about whether a document is answer providing or reduce it to a familiar kind of scientific disagreement about a passages meaning a statements correctness or an inferences correctness this seems better than treating relevance judgements as subjective and not open to rational discussion
CISI	information science toward the development of a true scientific discipline it is pointed out that if information science is to be considered a true science similar to physics or chemistry then it must have a set of concepts and analytical expression which apply to the flow of information in a general way in several previous papers the author and a colleague have described a model of a generalized information system which has wide and perhaps universal applicability this paper elaborates on this model and indicates the range of its applicability several fundamental quantities are defined specifically in a way which allows for quantification it is pointed out in this paper that this model can be the basis for the development of a true science of information with all of the necessary requirements for a science by the use of this model and the definition of a true science the goals and requirements for a curriculum in information science are thus established within this context information is defined as data of value in decision making quantitative measures of information can be obtained by relating information to specific observable actions which can be measured physically
CISI	a comparison of a keyword from title index with a single access point per document alphabetic subject index two indexes to a collection of 3 204 documents in the field of chemistry were test searched the indexes are a keyword from title index without added keywords and a single access point per document alphabetic subject index the indexes were searched by 13 graduate chemistry students using 55 questions search results are characterized in terms of recall precision and search time there is no statistically significant difference in recall and precision search result between the multiple access points per document keyword from title index and the single access point per document alphabetic subject index search time was significantly better for the alphabetic subject index for all but those questions having only one relevant document
CISI	a core nursing library for practitioners the following books and journals for the core nursing library suggested reference materials and supplementary books and journals were selected by experts in nursing from all parts of the united states the purpose is to let practitioners and community hospitals know which books and journals from a wealth of printed material would in the opinion of experts be most useful especially where funds and space are limited
CISI	patterns of name ordering among authors of scientific papers a study of social symbolism and its ambiguity with increasing scientific collaboration visibility of individual role performance has diminished ordering of author names as an adaptive device which symbolizes their relative contributions to research interviews with nobel laureates and comparisons of their name order practices to those of other scientists suggest that this symbol is ambiguous and makes evaluation of individual role performance difficult a probability model of expected distribution of name orders is used in measuring preferences for particular sequences and these preferences vary with the authors eminence on the assumptions that authors names are listed in order of the value of their contributions laureates should be first authors more often than other scientists in fact they are not instead they exercise their noblesse oblige by giving credit to less eminent co workers increasingly as their eminence grows they do so more often after the prize and eminent laureates to be forego first authorship more often than those as yet unrecognized the noblesse oblige however has its limits laureates contributions to prize winning research are more visible than contributions to their other research
CISI	professional standing and the reception of scientific discoveries the matthew effect occurs when scientists receive differential recognition for a particular scientific contribution depending on their location in the stratification system merton originally introduced the concept to explain the allocation of credit among authors of multiple discoveries or collaborators in this paper the concept is generalized to apply to all scientific work if the matthew effect were to operate the reception of papers of equal quality should be influenced by the location of their authors in the stratification system to test this hypothesis data are drawn from several studies of similar design in each study we control for the number of citations papers received at time 2 this enables us to look at groups of papers that were judged to be roughly equal in quality at time 2 we then see whether there were any differences in the reception of these papers at time 1 depending upon various aspects of the authors location in the stratification system all the data indicate that assessed quality of papers at time 2 is a more important determinant of a papers initial reception than any of the stratification variables however the speed of diffusion of papers of equal quality is influenced by the reputation of the author based on past work that is being heavily utilized at the time of a new discovery the matthew effect also operates for those scientists located at prestigious points of the social system of science all other stratification variables including eminence as measured by receipt of awards did not influence the speed of diffusion data are presented that indicate that top papers written by high ranking scientists are no more likely to be widely diffused early than are top papers by low  ranking scientists the matthew effect also serves to focus attention on the work of little known men who collaborate with scientists of high repute and to increase retroactively the visibility of the early work of scientists who go on to greater fame a discussion is included of the relevance of these data for the study of resistance to scientific discoveries
CISI	involving computerizing personalizing in most libraries most users face a complex monolithic arrangement of entries in catalogs and books on shelves in classical librarianship no effort can be made to personalize the listing of titles or arrangement of volumes for an individual user a user is unidentified and except for that small fraction of a percent who consult reference librarians users remain nameless the computer however with its superb ability to treat users as individual persons and events as individual events possesses the potential for enabling big libraries to recapture the human qualities of which classical librarianship has deprived them since their days as one librarian libraries however rehumanization is not the only contribution computerization will make to libraries developments in modern society are forcing libraries to establish new objectives contemporary living is information based a phenomenon that is outmoding the venerable concept of library function as small special libraries already do all libraries must participate in the cultural activities of the individuals in their communities rather than merely make available a torpid service libraries must look forward to supplying information to a user when and where he needs it   an objective impossible to attain with classical library techniques
CISI	williams wilkins   the great leap backward this article contains a call for active participation by all segments of the library and educational community in the williams and wilkins controversy and in the effort to achieve appropriate copyright revision
CISI	oclc for you   and me sometimes it seems as if the library world has divided into two camps those who seem to know all about this thing called oclc and who keep popping that rounded acronym into their conversation with a certain bromidic effervescence and the other camp   plain folk who are happy to take library life one acronym at a time as they need it and who if pressed might guess that oclc has something to do with oh optical codes at the library of congress only in ohio   where the ohio college library center began and where this national computerized bibliographic data exchange continues to grow   is oclc universally a library household term even among computer phobes in ohio most librarians already realize the kind of thing going on at oclc is not simply the building up of someone elses data base in little bits and bytes but perhaps the biggest revolution in access to library collections since books were unchained from the shelves
CISI	the american occupational structure this book is the result of a collaborative effort extending over seven years we have tried hard to make the book a genuine joint product to which each of us made the contributions he is best qualified to make there is no senior author the sequence of name is simply alphabetical and we have reversed it in signing the preface and elsewhere to emphasize this fact our collaboration was motivated by our shared interest in social stratification our common concern with advancing scientific social theory on the basis of systematic research and the conviction that the inquiry would benefit from the different qualifications and viewpoints the two of us represent there can be no doubt that our interests in and approaches to sociological problems differ to a considerable degree although we agree that refining research methods and advancing social theory are both important for example it is only fair to state that duncan lays more stress on deriving theoretical generalizations
CISI	american overseas library technical assistance 1940 1970 the united states has been engaged in activities known variously as technical assistance technical cooperation or development assistance for the past twenty five years this form of foreign aid either government sponsored or privately supported is a twentieth century phenomenon the broader concept foreign aid or foreign assistance means providing another country with any kind of goods whether financial commodity or manpower to almost any purpose and extends to antiquity technical assistance which may be defined on the other hand as the supplying of techniques is an outgrowth of the industrial revolution and parallels americas rise in the nineteenth century to world recognition as an important industrial and trade power government use of such aid as an instrument of foreign policy as well as the integration of these private and public efforts in the foreign assistance field began to develop under president roosevelts good neighbor policy this integration soon expanded under the new cultural relations program which the united states implemented during world war ii to offset the nazi propaganda and cultural offensive in latin america
CISI	scientific communication five themes from social science research the recent upsurge of interest in the behavioral aspects of scientific and technical communication and information flow has two distinct sources a theoretical one in the development of communication research and a practical one in the concerns of policy makers in scientific organizations and information services for some time past the attention of sociologists and social psychologists studying communication processes once focused on so called mass phenomena and mass publics has turned to the interplay of communication processes with more and more definitely delineated and mapped aspects of social structure one aspect of this shift in interest has been the increasing attention paid by behavioral scientists to the systems supplying information of a specialized sort and to the publics which are consumers of this specialized information the scientific and applied professions have been most prominent among the publics so studied
CISI	communication patterns in applied technology the preceding papers have addressed themselves to the study of information flow in a particular stream of human activity which has been variously called science pure science basic research or fundamental research and which is only secondarily if at all concerned with the practical utilization of its products at this point it is appropriate to note that there is a parallel activity which includes applied research exploratory development and engineering development this second stream of research we will call technology far more is known about the flow of information among scientists than among technologists from the knowledge that is available however we are led to conclude that the communication patterns in the two areas of activity are not only largely independent of one another but qualitatively different in their nature this difference is reflected most clearly in the mechanisms by which information is diffused within the two sets of practitioners the present paper is addressed to these differences and to a discussion of the nature of the communication process between science and technology
CISI	bibliographical citation characteristics of the psychological journal network in 1950 and in 1960 the aforementioned studies are related to the problem of information exchange in psychology journals are a part of the formal channel of scientific communication as well as storage elements for the summary accounts of research undertakings analysis of bibliographical citations thus can reveal certain characteristics of the pattern of information flow created by scientists in their work the potential usefulness of this type of investigation is increased when it becomes possible to examine the trends through time of the communication network under consideration and also when different communication networks can be compared the present paper deals with some of the characteristics of bibliographical citations in the same 21 psychological journals published both in 1950 and in 1960 the list of journals used along with the abbreviations to be used here is given in table 1 it includes 8 journals published by the american psychological association and 13 journals published by other organizations
CISI	scientific communication its role in the conduct of research and creation of knowledge there is considerable apprehension today within the scientific community over the communication crisis in science the present article which attempts to clarify certain aspects of the problem overviews the data collected by the apa project on scientific information exchange in psychology together with data which we have more recently obtained relative to other disciplines such a reexamination of the data should help to clarify apas relationship to the many information media involved in the communication process which begins with research and ends with the incorporation of research findings into psychological knowledge
CISI	ecological correlations and the behavior of individuals an individual correlation is a correlation in which the statistical object or thing described is indivisible the correlation between color and illiteracy for persons in the united states shown later in table 1 is an individual correlation because the kind of thing described is an indivisible unit a person in an individual correlation the variables are descriptive properties of individuals such as height income eye color or race and not descriptive statistical constants such as rates or means in an ecological correlation the statistical object is a group of persons the correlation between the percentage of the population which is negro and the percentage of the population which is illiterate for the 48 states shown later as figure 2 is an ecological correlation the thing described is the population of a state and not a single individual the variables are percentages descriptive properties of groups and not descriptive properties of individuals
CISI	priorities in scientific discovery a chapter in the sociology of science we can only guess what historians of the future will say about the condition of present day sociology but it seems safe to anticipate one of their observations when the trevelyans of 2050 come to write that history   as they well might for this clan of historians promises to go on forever   they will doubtless find it strange that so few sociologists and historians of the twentieth century could bring themselves in their work to treat science as one of the great social institutions of the time they will observe that long after the sociology of science became an identifiable field of inquiry it remained little cultivated in a world where science loomed large enough to present mankind with the choice of destruction or survival they may even suggest that somewhere in the process by which social scientists take note of the world as it is and as it once was a sense of values appears to have become badly scrambled
CISI	social factors in the origins of a new science the case of psychology the uninterrupted growth of a scientific field depends upon the existence of a scientific community permanently devoting itself to the field therefore the new idea is not sufficient to start the take off into sustained growth in a new field a new role must be created as well in scientific psychology this occurred in the late nineteenth century in germany using germany as a positive case and france britain and the united states as negative cases it is shown that the new role resulted from academic career opportunities favoring the mobility of practitioners and students of psychology into other fields and from the relatively low academic standing of speculative philosophy and its consequent receptivity to persons and ideas which promised to turn the study of the human mind into an experimental science
CISI	scientific output and recognition a study in the operation of the reward system in science the relationship between the quantity and quality of scientific output of 120 university physicists was studied although these two variables are highly correlated some physicists produce many papers of little significance and other produce a few papers of great significance the responses of the community of physicists to these distinct patterns of research publication were investigated quality of output is more significant than quantity in eliciting recognition through the receipt of awards appointment to prestigious academic departments and being widely known to ones colleagues the reward system operates to encourage creative scientists to be highly productive to divert the energies of less creative physicists into other channels and to produce a higher correlation between quantity and quality of output in the top departments than in the weaker departments
CISI	nobel laureates in science patterns of productivity collaboration and authorship nobel laureates in science publish more and are more apt to collaborate than a matched sample of scientists interviews with 41 of 55 laureates and comparison of their research output with the output of the matched sample indicate that these patterns hold at every stage of the life work cycle as laureates report and as their publications collaborate they exercise noblesse oblige in arranging co authorship in collaborative publications receipt of the nobel prize is followed by declining productivity and changed work practices as a result of changed role obligations and activities reductions in productivity are more severe for laureates who experience comparatively large increments in prestige through the prize than for those who were already eminent the prize generates strain in collaborative associations so that most of these terminate soon after the award
CISI	visibility and the structural bases of awareness of scientific research the paper contains an analysis of several aspects of the communication process in science using data obtained from printed sources and questionnaires mailed to university physicists the conditions making for high visibility of a scientists work are studied four strong determinates of visibility were found the quality of work as measured by citations the honorific awards received for work in physics the prestige of the physics department to which the scientist belong and speciality quantity of output age and name ordering patterns on collaborative papers have no independent effect on visibility just as some physicists may be easily seen i e have high visibility other are in positions where they may easily see this latter characteristic is called awareness the data indicate that awareness is high in all sectors of the population studied variables such as age rank of department and quality of work made for only minor differences in awareness we conclude that the communication system in physics operates efficiently
CISI	social structure in a group of scientists a test of the invisible college hypothesis the existence of social organization within a research area may be inferred a if scientists who have published in the area have more social ties with one another than with scientists who have not published and b scientists who have published in the area can be differentiated by degree od social participation within the area using the mail questionnaire sociometric data on different types of scientific relationships were obtained from scientists all of whom had published in a particular problem area respondents chose scientists who had not published in the area as often as they chose scientists within the area analysis of direct and indirect ties using clemans method for analysis of sociometric connectedness revealed that a tie with one or more of the highly productive scientists brought other scientists of less productivity into a large network of influence and communication similarities between this type of social organization and that of the social circle are discussed
CISI	growth and decay curves in scientific citations in a rapidly advancing scientific discipline new contributions will supersede older ones this selection in favor of recent literature should be observable in the distribution of footnote citations in a given discipline by age of article cited however the age distribution of citations also depends on the rate of growth of the disciplinary literature the effect of growth of the literature and of selection favoring recent articles can be separated if certain assumptions hold by use of an exponential model that expands and clarifies earlier findings by price this model provides a reasonably good fit to age distributions of footnotes in several disciplines and its application suggest that citations in sociology tend to refer to older articles than those in the natural sciences a parameter in the model measuring the degree of selectivity in favor of recent articles can be estimated and may be useful in comparative studies of the communication systems of various disciplines
CISI	the structure of scientific fields and the functioning of university graduate departments kuhns concept of paradigm suggests that academic disciplines could be viewed as technologies involving degree of task predictability a series of hypotheses were developed in which relatively high paradigm development in a discipline was predicted to facilitate research and teaching through improved processes of communication and access to stored information using questionnaire data collected from 80 university graduate departments physicists and chemists were found to exhibit more agreement over field content and to be more willing and satisfied to spend time with graduate students than sociologists and political scientists in addition chemists were found to collaborate with larger numbers of graduate students in research than scientists in the other fields two other aspects of scientific structure are discussed the level of innovation being pursued within a field of a given time and the degree of institutionalized differentiation of the field into subdisciplines
CISI	productivity differences among scientists evidence for accumulative advantage the highly skewed distributions of productivity among scientists can be partly explained by a process of accumulative advantage because of feedback through recognition and resources highly productive scientists maintain or increase their productivity while scientists who produce very little produce even less later on a major implication of accumulative advantage is that the distribution of productivity becomes increasingly unequal as a cohort of scientists ages cross sectional survey data support this hypothesis for chemists physicists and mathematicians who show strong linear increases in inequality with increasing career age this increase is highly associated with a changing distribution of time spent on research another implication of accumulative advantage is also corroborated the association among productivity resources and esteem increases as career age increases
CISI	the distribution of social and cultural properties in informal communication networks among biological scientists informal communication among biological scientists forms a discernible social structure this research analyzes the relation of that structure to 1 scientists descriptions of their research and the orientations that underlie those descriptions 2 social status in science and 3 the formal social categories of science i e discipline department and research organization each of the observed structures is contrasted with a random model neither social status nor the formal social categories show greater association on the social structure than to the random model the culture of science on the other hand as represented by description of research and the orientations underlying those descriptions shows very strong associations with the discerned network structures
CISI	the gatekeepers of science some factors affecting the selection of articles of scientific journals the norms of scientific behavior as described by merton include the prescription that scientific achievements are to be judged without reference to scientists social characteristics this article will attempt to assess the extent to which this norm is followed with respect to the evaluation of articles by scientific journals
CISI	bibliographical reference patterns in core sociological journals 1965 1966 the present study attempted to extend previous work on bibliographical reference patterns in sociological journals in the following ways 1 by selecting for study those journals to which american sociologists prefer to submit their work 2 by including over a two year period all bibliographical references journals books technical reports etc and 3 by including for initial comparison a journal from the physical sciences such a study it was hoped would yield data concerning similarities and differences among the sociological journals and between the sociological journals and the physical science journal
CISI	sociology today lacunae emphases and surfeits in sociology today as in other sciences the professional journals serve as major channels for the dissemination of ideas and information the papers presented in the principal periodicals reach a wide audience among sociologists are acknowledged as the best work and stand as models for all who aspire to success the viewpoints conceptual schemes interests and methodologies reflected in these articles are therefore significant influences on both the current character and the future development of our discipline
CISI	measuring the quality of sociological research problems in the use of the science citation index the problem of assessing the quality of scientific publications has long been a major impediment to progress in the sociology of science most researchers have typically paid homage to the belief that quantity of output is not the equivalent of quality and have then gone ahead and used publication counts anyway coler 1963 crane 1965 price 1963 wilson 1964 there seemed to be no practicable way to measure the quality of large numbers of papers or the lifes work of large numbers of scientists the invention of the science citation index sci a few years ago provides a new and reliable tool to measure the significance of individual scientists contributions starting in 1961 the sci has listed all bibliographic references appearing in an increasingly large number of journals the number of citations an individual receives may be tabulated and used as an indicator of the relative scientific significance or quality of that individuals publications
CISI	the analysis of information systems this book is intended to supply the background needed for participation in the analysis and design of information handling systems and for understanding the literature in the field i have tried to present a unified approach to the subject and to the relation of information retrieval to other disciplines and an appreciation of the importance of this interdisciplinary relationship i hope that the scientist or computer programmer newly interested in information retrieval problems as well as the librarian will find the book of value
CISI	analysis of library user circulation requirements this research study is concerned with the use of the last circulation date as a statistic to help describe library user circulation requirements some decision rules were developed to use this parameter as an aid in determining the number of copies of books to be held in the library and as an aid in the weeding of books from the librarys holdings the effect of these decision rules on the circulation requirements of users as well as on library operations are described the method of data collection is described in detail and is applicable at libraries having comparable charging systems cumulative distribution functions of last circulation date at two large college libraries and a public library were prepared and have been plotted for both circulation data and stack holding data this same data has also been plotted by subdivided subject category circulation operating characteristics were prepared for all three libraries
CISI	the documentation of chemical research due to the fact that scientific technical research is constantly increasing it is becoming more and more difficult to retrieve the published results of research a new field of science documentation has been developed as a contribution to the removal of this difficulty depending on the type and extent of the subject different methods for its documentation will be followed methods and possibilities for the comprehensive documentation of chemistry and its related fields are explained
CISI	tosar   a topological method for the representation of synthetic and analytical relations of concepts in mechanized systems used for searching in literature stores there is a steadily growing necessity not only to be able to formulate concepts as a search condition but also the characteristic connections under which these concepts appear in the inquiry in this way the precision of the mechanized literature search is considerably increased tosar has been developed in order to improve computerized literature searching in this respect
CISI	animal dispersion in relation to social behavior the theory presented in this book links together the subjects of population and brhavior it applies to animals in general which gives it an exceedingly wide scope
CISI	information networks in the literature active network plans and developments appear to cluster in three main areas 1 education 2 libraries and 3 government industry and professional societies these network groupings are described in this chapter following a discussion of network definitions concepts and current impetus references to information systems are included when there is an indication that a particular system will probably be transformed into a network
CISI	design and evaluation of information systems in corresponding chapters of earlier volumes of this review may be discerned a trend toward progressive broadening of content coverage the initial emphasis was on design and evaluation concepts and on techniques that were rather closely   and narrowly   connected with information storage and retrieval systems it is becoming increasingly clear however that there are many activities and ideas outside of this context that have or can have a very important bearing on the work of systems analysts designers and evaluators working on library and documentation systems this chapter attempts to continue enlarging our perception of the range of reported activities that can help to improve the kinds of systems in which our readers are chiefly interested
CISI	document dissemination this chapter is directed to those whose vocation or avocation is information while we may call ourselves librarians information scientists or technologists abstractors and indexers documentalists is r specialists literature searchers and so forth we all have one thing in common we are either directly or indirectly involved in the dissemination of information as disseminators we are interested in far more than the techniques for transmission of information from one point to another despite mcluhans 93 statement that the medium is the message we must concern ourselves with not only the means of document dissemination but also the content and value of the documents we disseminate this idea is prevalent throughout most of the papers reviewed in this chapter a disseminator should think of himself as a selective switching center inputting data evaluating them selecting worthy items and directing and controlling their transmission to a target the reader
CISI	information networks the rapidly growing rate at which information is produced and used in our complex society has presented us with major problems in information transfer we encounter these problems not only in libraries information centers and schools but also in many of the operations of government and business the handling of large amounts of information is becoming a dominant theme in the management of our way of life we are a technologically oriented society and we have naturally turned to our communications technology to help us perform our enormous information transfer task beginning with the telegraph and continuing through the telephone through radio and television to the communications satellite the methods of electrical signal transmission have served to distribute information to its ultimate users
CISI	annual reviews of information science and technology in spite of concerns expressed in the literature about the health and vigor of the field of information science and of its service oriented institutions   libraries and information centers   the progress reviews in this volume provide grounds for optimism some of the trends that were commented on in volume 6 have proved to be solid and important for example the movement toward rapid interactive access to major public and commercial data bases is not very strong and it will probably not be many years before satisfying experience with this new mode of information access will help it become not merely an experimental innovation but the standard means of searching and using centrally or regionally held data three chapters in this volume touch on related aspects of the movement bennetts review of the user interface in interactive systems gechmans report on machine readable bibliographic data bases and brandhorst and eckerts review of document retrieval and dissemination systems this volume also introduces a new annual review topic of potentially great importance for future libraries video cartridges and cassettes it is widely accepted that libraries and information centers will in the coming years shift the balance of their holdings in the direction of some of the newer media and the chapter by kletter and hudson helps to define the potential and problems of some of the promising new media other new areas of interest are information system applications in the criminal justice system and information system applications in the humanities in addition to these topics this volume covers three of the core areas of information science which we attempt to review on as close to an annual basis as possible information needs and uses document description and representation and organization of information this coverage is consistent with a newly developed annual review master plan for cyclic but flexible coverage of some 40 major areas of interest in library and information science
CISI	the user interface in interactive systems the digital computer has been used as a problem solving tool for only two decades during most of this time computer scientists have concentrated on learning how to build the tool applying electronic technology arranging for data flow between components and manufacturing the hardware now we are entering a new stage in which computing power is made available through interactive terminals to people who are not computer scientists this is possible on a large scale only because design and marketing innovators now have confidence in their ability to provide reliable cost effective service to less sophisticated users in this new stage the natural behavior patterns of users become an important element in the design of the interface to the tool
CISI	machine readable bibliographic data bases the advent of machine readable data bases is one of the most significant forward steps in information retrieval currently the creation and application of these data bases are in a period of very rapid growth this reviewer sees a great need for a review of what is going on because there is so much going on it is the goal of this chapter to fulfill that need even though it is difficult to hold this dynamic field static for a good meaningful look
CISI	annual reviews of information science and technology the major trends of the 1970s in information system planning and services are becoming clear as indicated in this years annual review chapters the movement toward inter institutional operations or networking began gaining force in the 1965 1970 period through the establishment of many new library consortia and there were some tentative efforts to use computers for nationwide bibliographic information utilities these movements are now more vigorous and are showing signs of being cost effective productive ventures inter institutional cooperation not only promises service improvements and cost reductions but also poses new problems and demands formalized cooperation among different institutions requires agreement about needs and priorities and gives special importance to a clear understanding of the information needs of specific user subgroups it also requires more careful and productive system planning and design including intelligent consideration of the make versus buy issue several chapters in this volume touch on these problems and considerations one of the most significant developments in 1973 was the rapid growth in the use of on line information retrieval services   both those operated by the federal government and those operated by the private sector the apparent cost effectiveness of these services is raising some of the same problems for data base producers that inter institutional cooperation among library and information facilities is raising for the publishers of printed materials namely how to cover rising costs in the face of declining or less rapidly growing sales of individual units of the product   monographs serials secondary information publications or magnetic tapes the inclusion of a chapter on copyright   the first in the annual review series   reflects the importance of this topic in the growing controversy over the ownership and distribution of information another aspect of that controversy   the role of government and non profit information services in relation to those of private industry   is explored in this years chapter on document retrieval systems and techniques
CISI	use of machine readable data bases this is the first annual review chapter entitled use of machine  readable data bases therefore the coverage provided is for more than a one year period a chapter by gechman 79 on machine readable bibliographic data bases included literature from 1969 through 1971 a chapter by housman 100 covered the use of data bases for selective dissemination of information sdi and a chapter by parkins kennedy 153 has previously reviewed secondary information services this chapter will cover the 1973 literature on data bases as well as earlier data base papers not treated in prior chapters for purposes of this chapter a data base is considered to be an organized set of machine readable records containing bibliographic or document related data
CISI	design and evaluation of information systems the co joining of design with evaluation that is called for by this chapter posed organizational and inclusion exclusion problems for the author in part design and evaluation prescribe two separate sets of activities the former pertaining to the planning development and testing of new information system structures and modification of existing structures the latter to appraisals and assessments of operational systems and system components however design includes not only the formulation of goals and objectives for systems but also provisions for evaluation in accordance with expectations evaluation applies to testing design concepts and to trying out preliminary implementations for the purpose of improving initial designs as well as to the appraisal of operating systems appraisals at any stage of system operability may yield data that indicate the need for system modifications that require redesign and assessment thus portions of design and evaluation are closely interrelated as katter demonstrated in his 1969 review design and evaluation may be examined methodologically or with respect to outcomes of the application of methodologies increasingly designers and evaluators have been acknowledging the dependence of outcomes on sound procedural conceptualizations the current literature discloses research on the processes of design and evaluation as well as on their products
CISI	generation and uses of machine readable data bases this chapter continues the coverage of the generation and use of machine readable data bases inaugurated in volume 9 by williams 178 it is therefore an update consisting primarily of 1974 material and is prepared in general accordance with williamss initial compilation the same definition of data bases and the boundaries of their applications used in volume 9 are continued this year a data base is considered to be an organized collection of machine readable records containing bibliographic and or document related data e g index information the data bases that we will consider are used for information storage and retrieval and or research in information storage and retrieval or data base generation the choice of these constraints precludes coverage of several areas first data bases primarily concerned with numerical or other nonbibliographic information such as chemical structures milen et al 112 are excluded thus even though the chemical abstracts service cas registry number is a data element common to many bibliographic data bases papers such as that by cas regarding progress in building the registry system itself 39 are excluded similarly though some textual and bibliographic material is included in the systems consultants inc report 156 to the navy most of the information retrieval is concerned with miniaturized hardware in a shipboard environment and thus is not considered within the scope of this chapter finally though many of the data bases are used for generation of publications via phototypesetting we are not considering that production operation
CISI	cooperation in information activities through international organizations international cooperation in the processing sharing and transfer of scientific and technical information takes many forms and can be accomplished through many agencies this chapter proposes to review the role played by international organizations in stimulating and providing channels and mechanisms for such cooperation the international organizations to be discussed are of two types intergovernmental organizations igos in which member nations participate through their governments under formal treaties or agreements and nongovernmental organizations ngos where with some exceptions participation is through national professional societies or nongovernmental institutions the specialized agencies of the united nations including unesco fall in the first category organizations such as the international federation for documentation fid are in the second
CISI	introduction to the adi annual review over the past 15 or 20 years a new and growing field of inquiry has begun to take shape this field which will be referred to as information science and technology draws on fragments and fringes of a number of sciences technologies disciplines arts and practices the element that provides whatever degree of cohesiveness now exists in the field is a shared deep concern with information   its generation transformation communication storage retrieval and use because of the universality of information processes and also because of the variety of backgrounds of those concerned with them there is very little agreement about the boundaries of information science and technology or about its parentage its essential nature or its future to put it simply at the present time there is no clearly defined and well understood field of information science and technology there is not truth to tell even clear agreement on what the word information itself means and particularly on whether it implies a creative act of the intellect or a commodity that can be embodied in documents transported and exchanged distressing as this ambiguity and lack of agreement may be they need not and do no preclude a constructive review of topics of current interest to users designers and students of information systems and services the purpose of the adi annual review series initiated in this volume is to provide such a review
CISI	information needs and uses in science and technology the way in which scientists and engineers make use of the information systems at their disposal the demands that they put to them the satisfaction achieved by their efforts and the resultant impact on their further work are among the items of knowledge which are necessary for the wise planning of science information systems and policy besides these matters can be of great significance to the behavioral scientist interested in human organization and communication while user studies have not yet gone very far in serving either of these functions the end of 1963 seems to have been something of a take off point for empirical research on the information needs and uses of scientists and technologists for this first volume of the annual review we shall therefore cover studies that made their appearance as far back as the last month of 1963 to give the reader a rounded picture of a period during which this area of research has witnessed progress along the following lines substantial advances in the more systematic and fruitful application of a technique critical incidents that had made its appearance in this field earlier in less rigorous forms the introduction of at least two very promising approaches solution development records comparison of research teams working on identical tasks quite different from any that had been applied to this field before and an increase in the number of efforts at comprehensive study of the information flow situation in given disciplines one of which american psychological association 3 has become the model and envy of research in this area
CISI	the annual review of information science and technology this volume is the second in a series of annual reviews of progress in the field of information science and technology like its predecessor it attempts to describe compare and evaluate the most significant work that has been reported in the field during the past year the effort has been undertaken in the belief that such taking stock of accomplishments provides a valuable service to the specialists in the information science field the chapters on new techniques for publication and distribution of information on new developments in chemical documentation and on applications in medicine
CISI	evaluation of information systems and services this chapter summarizes and discusses the present state of the art in testing and evaluation three tasks will be undertaken to outline in some detail the few substantive research projects involving testing and evaluation to describe a number of research projects in areas cognate to testing and evaluation and finally to provide some general conclusions with respect to past and future activity although a distinction is made in this review between laboratory based experimentation and tests of operational systems the methodology used in each instance is substantially the same as yet no full scale and elaborate field approach has been attempted
CISI	design of information systems and services this review has selected for emphasis reports on concepts of systems analysis and on the procedures for applying these concepts to the design of information systems literature dealing with the automation of libraries and information centers has been explicitly excluded while material on user studies file organization evaluation etc is only mentioned briefly since it is covered more thoroughly in other chapters the selected relevant and available literature that has been published in the last year or so is organized into four groups as follows 1 articles that help define the process of systems analysis and the relationship to information science 2 articles that describe the concepts of systems analysis as applied to the analysis and design of information systems 3 articles primarily concerned with the design of document storage and retrieval systems
CISI	the annual review of information science and technology the annual review of information science and technology is now in its third year like its two predecessors this volume attempts to describe and evaluate the most significant work that has been reported in the field during the past year with the ultimate aim of improving both our standards and our means of professional communication the field of information science and technology continues to evolve and grow as it does new areas of interest emerge and established areas of interest change in importance accordingly our pattern of coverage changes the single chapter on automation in libraries and information centers in volume 2 has been expanded into two chapters one covering automation of technical processes and the other covering document networks and a new chapter has been added on information system applications in education such applications are important not just because they involve in part libraries and other information facilities but because they highlight innovative ideas and techniques that should be of value to anyone interested in the total communication process at the same time core chapters of the review are continued information needs and uses content analysis specification and control file organization and search publication and distribution techniques automated language processing man machine communication information system design and evaluation and professional aspects of information science these topics are of continuing and vital interest to our readers and their annual literature is significant large and growing
CISI	information needs and uses information science meets behavioral science in the study of information needs and uses at first the meeting of these fields was inconclusive until the mid 1960s there were only a few substantial studies of information needs and uses since about 1963 however a significant literature has grown rapidly there is evidence now of a productive entente between the fields when information scientists see reliable valid and nontrivial data on users behavior they begin to use behavioral criteria in evaluating information system performance when behavioral scientists glimpse the full complexity of dissemination documentation storage and retrieval processes they offer fewer naive solutions to the information problem this mutual education and accommodation will undoubtedly continue information science and behavioral science need each other big science needs them both
CISI	the annual review of information science and technology this the fourth volume of the annual review of information science and technology is both like and unlike its predecessors the basic objective   to provide the most comprehensive and technically sound progress review ever prepared in the information science field   remains the same as do the basic areas of interest and coverage too the primary emphasis continues to be on published literature and reports to permit the reader to identify locate and examine interesting and important sources of information about various aspects of our technical progress some new areas of growing importance are introduced this year for the first time a chapter on reprography and microfilm technology and one on the international aspects of information transfer have been included also the topics of document dissemination and the secondary services usually covered in parts of other chapters have full and separate chapters this year another change made in response to suggestions from readers for better signposts within each volume is the division of the book into several major segments each introduced by a short description of the contents of the section the relationships among the chapters within it and in some instances one or two highlights of the years technical progress
CISI	information needs and uses previous authors in this series writing on this subject have usually felt it necessary to begin with a statement concerning the state of the methodology of user studies they have for the most part found it improved over the past and this year is no exception in that regard there remains however the tendency on the part of many who are untrained in social science methodology to assume that the art of questionnaire design and administration is a very simple one that anyone with intelligence can master in a single attempt one never realizes how truly wrong this view is until he finds himself the author of a review chapter and is then confronted with the sort of trivia that many authors submit as research papers
CISI	annual review of information science and technology the field of information science and technology continues to grow and as it grows to show new emphases and explore new areas of interest volume 5 reflects these changes the increasing interest in and movement toward library networks and other cooperative technology supported information activities have helped to focus special attention not only on data processing and microfilm technology the two traditional mainstays of library and document handling systems but also on the rapidly developing capabilities in modern tele communications thus a chapter on communication technology has appeared for the first time to bring readers up to date on changes in the communications industry that have had or will have a great impact on how we design and use information handling systems two other first time chapters cover management information systems and information systems in state and local government while the intent behind the development of such systems and the kinds of services they provide is peripheral to the purposes and services of library and document handling systems one often sees in these peripheral areas some information parallels indeed one of the reasons for the annual reviews covering one or more of these areas each year is to help its readers exploit more fully the thinking and the problem solving techniques they are fostering
CISI	application of computer technology to library process a syllabus the application of computer technology to library and network processes and services is not an end in itself but rather a means of narrowing the gap between the demand for library services and the ability of libraries to provide those services libraries have assumed the active role of serving the informational educational and recreational needs of the population the size of that population grows constantly its educational level keeps climbing and its percentage of leisure time is increasing the application of computer technology to libraries especially to the manipulation of bibliographic records in the performance of library functions is a complex process and demands the highest level of talent of both the library and computer professions for its accomplishment it cannot be accomplished by either profession alone rather the design of a library system is a team effort between librarians computer system analysts and programmers even a limited effort demands careful long term planning if it is to fit with later efforts into a cohesive whole the smallest project will affect nearly all operations of the library for these reasons it is necessary that all library staff have at least a general overview of what library automation is all about
CISI	archives and library relations a distinct characteristic of man is the need to communicate and record knowledge the tools of communication have ranged from clay to satellites civilized societies have taken great pains to place recorded knowledge in safe places and create archives and libraries for this purpose the importance of recorded knowledge for survival and progress is constantly being elevated as more and more information is presented without information and its necessary control a society is not only stagnant but regressive with social memory preserved and controlled by archives and libraries a society is able to evolve to whatever future it is destined to experience in an ever changing environment archives were the forerunners of libraries the ancient archives contained the best of societys accumulated knowledge and as nations grew in wealth and security archives and libraries become symbols of a countrys aspiration to create a better society today archives and libraries are necessities these cultural institutions pass information to succeeding generations in a variety of forms of distributable media in this way archives and libraries preserve the memory of civilization and pass this memory on to living individuals the materials in these institutions contain the written and graphic record of social memory and human heritage and provide society with information on which to base actions develop policies ascertain rights educate and entertain
CISI	the area specialist bibliographer an inquiry into his role it is the intent of this volume to develop a model designed to eliminate present difficulties and ambiguities and to improve administrative procedures for future development of area programs this will be accomplished by giving some indication of the climate of opinion toward area specialist bibliographers and by isolating factors which influence these opinions these attitudes will be presented by the perceptions of area bibliographers toward their role and the expectations of faculty and library administrators toward that role the bibliographers academic professional and educational experience will be examined in this framework
CISI	the art of computer programming the process of preparing programs for a digital computer is especially attractive because it not only can be economically and scientifically rewarding it can also be an aesthetic experience much like composing poetry or music this book is the first volume of a seven volume set of books that has been designed to train the reader in the various skills which go into a programmers craft
CISI	asidic survey of information center services the data in that survey covered the year 1971 many recipients of the 1972 document have requested updated information accordingly the asidic cooperative data management committee initiated a new survey the questionnaires were mailed out in january of 1975 and responses came in throughout the year questionnaires were sent to all member organizations of asidic and eusidic questionnaires were also sent to individual members of asis sig sdi and sig uoi responses received throughout 1975 were checked and tabulated in 1976 because of the time delay in producing the final compilation the reader is warned against using this survey as an up to date source for information as to which centers are processing which data bases of the 116 responding organizations 75 process data bases and 41 use data base services either as end users or as brokers of the 75 that process data bases i e spin tapes 51 68 are members of asidic and or eusidic this survey provides representative data for data base processing organizations the use of online search services was relatively new in 1974 hence data regarding online users would not be representative of the 1976 online situation
CISI	the testing of index language devices in this paper we set out the fundamental operations involved in compiling and using an index show how the various factors can influence the operating efficiency and consider the methods to be used in the present aslib cranfield investigation
CISI	research on users needs where is it getting us since bernal made his pilot survey of the use of scientific literature for the 1948 royal society scientific information conference at least three dozen other investigations have been reported of the needs of scientists and engineers for information of their information gathering habits and the use to which they put information some of these have been concerned with the people in individual organizations but have implications elsewhere others including aslibs own investigations have had wider aims some have been based upon observations and records of what the scientists and engineers themselves did or said and some upon records of the demands they made upon libraries there have been both surveys of opinions and collections of facts
CISI	fair fast access information retrieval project aims and methods i am going to describe in general terms a research project which has been established to explore some of the problems of the use of the literature particularly in the field of biomedical engineering of the national institute for medical research hampstead laboratories the project is scheduled to last for three years and like most research consists of a number of overlapping stages we have reached the stage now of having acquired sufficient equipment and data to start trying out some of our ideas
CISI	the cranfield tests on index language devices the investigation dealt with the effect which different devices have on the performance of index languages it appeared that the most important consideration was the specificity of the index terms within the context of the conditions existing in this test single word terms were more effective than concept terms or a controlled vocabulary
CISI	current awareness searches on ct cbas and asca during the past year we have been one of the organizations participating in the chemical societys experiment on the use of routine computer searches of chemical titles ct and chemical  biological activities cbac for current awareness for some time we have also been subscribing to the automatic subject citation alert asca which is produced by the institute for scientific information as a by product of the science citation index these three sources differ in their scope and methods but share the same ultimate objective of providing a computer based current awareness service ct covers journals in all branches of chemistry but provides only authors and titles the latter translated into american and edited by breaking down complex words so that word fragments can be retrieved cbac covers only papers on the interaction of chemical compounds with biological systems but provides abstracts which are available for computer search the computer can also search for molecular formulae and for chemical abstracts registry numbers of all compounds included in the abstracts asca in its original form was based on citations the search profile can consist of a list of references to older work and the output is then a list of new papers citing this work last spring asca introduced a term search which is a search for words in the titles of current papers and is therefore analogous to a ct search this paper discusses and compares the results we have obtained so far with these three services and the potential use of systems of this type
CISI	thesaurus compilation methods a literature review this review has been sponsored by the office for scientific and technical information and the end product of the complete research will be a thesaurus of management terms parallel research in the business management area and also supported by osti is being conducted by david dews librarian of the manchester business school and k d c vernon librarian of the london graduate school of business studies as mr vernon is at present engaged in the construction of a faceted classification scheme for management this investigation has concentrated on the possibility of utilizing faceted techniques to construct such a thesaurus a study of existing information retrieval systems in the management field has already been made so a decision to adopt some form of post co ordinate indexing was assumed thus a comparative study of other systems will not be attempted a decision has also already been made that a controlled vocabulary i e a thesaurus was eventually going to be developed despite the latest cranfield results that appear to provide evidence of the superiority of natural language over controlled vocabularies this was primarily because these results were restricted to tests on an aeronautical collection and it may well be that the natural language of this discipline is in itself a fairly controlled one which is certainly not the case with the rather soft language of management this is borne out to some extent by halkin who quotes relevance figures for coordinate indexing applied to organic chemistry 55 percent engineering 35 percent and social science 20 per cent machine methods of term generation as described by ovchinnikov mastermann and luhn will not be considered as there is no equipment available to prepare thesauri on the lines these authors suggest
CISI	organizational aspects of information flow in technology for about five years now a small group of us at mit have been conducting a series of investigations into the information needs of technologists the manner in which these needs are presently met the relation between various ways of fulfilling information needs and technological performance and the nature of factors which determine the ways in which information needs will be fulfilled
CISI	criteria for evaluating technical library effectiveness in july 1966 john i thompson company accepted a contract with the picatinny arsenal us department of the army to perform a study aimed at developing criteria for evaluating the effectiveness of library operations and services under the atlis program army technical library improvement studies the study was divided into three phases aimed at i a literature search to reflect the current state of the art covering library standards and the methods of evaluating libraries developed up to the present ii a phase in which to gather and evaluate any data required from army technical libraries from available surveys already published or from any other sources by which to develop criteria iii a phase in which to establish and validate the criteria phases i and ii of the study are now complete phase iii is in progress and is expected to be completed by the late fall of 1968 the reports of phases i and ii are already available for detailed study and that of phase iii will be available soon the purpose of this paper is to present some of the findings of the study
CISI	the udc in its international aspects universal decimal classification   dying duck or live bird   or some such title   was suggested to me but this is highly debatable and there will hardly be time for the duck shooters to develop a concerted onslaught in the half hour or so allowed us for discussion besides i hope to be able to convince you   if the bsis fine efforts have not already done so   that the udc is by no means the dying duck   certainly not the dead duck   that some of its severest critics seem to imagine perhaps the bird has ceased to soar as it once did in the times of otlet la fontaine bradford and donker duyvis but that it is still viable in the turbulent air of current documentation may be gauged from a recent fid inquiry aimed at obtaining figures for the distribution of udc editions and an approximate estimate of the number of users throughout the world
CISI	subject relations in science technology literature the analysis of citations has often been employed to indicate the use of the literature of science and technology citation is only an indicator of use not an accurate measure and like all such indicators has defects differences between indicators have been discussed elsewhere despite these defects an examination of citations does enable one to sample acts of literature use within a large community the study reported here was directed in fact to all united kingdom authors of science technology publications in a given year and because of its width and the type of analysis performed is considered to be worth reporting the study was primarily undertaken to obtain comparable information about social science literature and this has been reported elsewhere
CISI	letter to the editor assessment of information services may we please raise four questions which are important at the present time when government policy on information retrieval is being considered these arise from results recently produced by sdc which are germane to dr somerfields paper on computer based information services aslib proceedings 20 12 542 50 1968 and to ostis work in this field the sdc is making comparisons of the efficiency of various published indexes and other sources of scientific information and the first results of rigorously checked comparisons are becoming available for a case study on the subject of computers related to mass spectrometry this results from an extensive literature search prepared by combining and collating results of searches in twelve of the worlds major indexes to chemistry and spectroscopy including searches of sdcs own data bank files nearly two hundred unique references on computers related to mass spectrometry were found and are being checked individually for relevance going back to the original paper or asking expert opinion where necessary
CISI	on the design of information systems for human beings planning of any kind can be motivated by a pressing practical problem which has to be solved   for example an increasing number of people may have to be housed in the same area or by a long term idealistic vision or by both the idealist seeing the long term implications of an immediate problem in short term planning the danger exists that the more technical problems may be solved without attention to their implications for human beings to take my housing example higher and higher flats may be built without considering the possible effects e g the effect on social groupings in long term planning utopian or ideological blueprints may be produced
CISI	standard costing for information systems background to a current study for some time past interest has been developing within the aslib research department in the problems of establishing standard costs for information systems a literature search recently conducted by the department r reynolds has revealed a scarcity of usable information on this subject such data as is available is difficult to evaluate comparatively because of the differing definitions of the operations costed and of the terms used to describe them it would seem therefore that a first step towards developing a costing method of widespread application would be the establishment of standard conventions for the analysis of information systems one might postulate two possible ways of arriving at comparative costs for these systems namely a general survey method the overall costs of a large number of information systems are broken down into a small number of categories and analysed for correlation see for example c j wessel et al b in depth study a small number of systems are studied in detail in an attempt to establish the true sources of the costs and factors affecting them in a current project we are attempting to apply method b to the production of current awareness bulletins an outline of some of the preliminary work in this project follows
CISI	an information retrieval language for marc i see from the programme that i am supposed to talk on an information language for marc and it is true that the work i have been doing for the past year or so has been under the auspices of the marc project but the subject indexing system we have developed is concerned as much with bnbs plans for computer production from 1971 as with the marc tapes as such and i hope to show that we have also gone some way towards developing a compatible general system with even wider application before coming to this however it is necessary to describe briefly some of the day to day pressures of work which caused bnb to look to the computer for help from this we can see how the computer forced us to reconsider our whole approach to subject indexing
CISI	analysis and organization of knowledge for retrieval in a university the mode of research is usually what is called pure or basic research since i am keeping in mind primarily the applications of information science i will prefer the word basic although there is not so much difference in such research and really in any good research one should not be collecting data haphazardly one must isolate and define a problem and as far as possible control other conditions so that interfering factors are eliminated preferably one will narrow down the problem to manageable proportions it is then essential to approach the problem with some sort of hypothesis or theory of the situation and to concentrate on obtaining evidence for or against that hypothesis the important task is to devise just that crucial experiment which will give the answer as efficiently as possible if the answer disproves the hypothesis one has at least further evidence upon which to construct a different hypothesis if it confirms the hypothesis one is ready for a further step forward and so on research is easier in a fully controlled and reproducible situation in a biological or human situation one must often have recourse to statistical methods but this does not alter the general methodology on the whole i find a clear methodology lacking in much that is being done in the field of information science today
CISI	user studies a review of the literature from 1966 to 1970 my terms of reference when asked to prepare this review of user studies were to bring fishendens work up to date this was published in the journal of documentation in september 1965 and in his paper he looks at a limited number of british use studies and draws some broad general conclusions relating to the development of a national information service the present paper which covers the literature back to the beginning of 1966 is somewhat more detailed it considers a wide range of investigations into the information gathering habits of scientists engineers social scientists and others and reports results which it is hoped will provide managers with information on which to develop policies regarding library and information services at all levels although an increasing number of studies is being carried out in eastern europe and in the ussr there has been no major work reported and consequently the review considers mainly british and american investigations
CISI	library and information science abstracts the first two years with the thirteenth issue affected by the recent postal strike now seems an opportune moment to take a look at the performance of lisa in its first two years this bi monthly abstracts service succeeded the former library science abstracts in 1969 as a joint venture between the library association and aslib a recount of its birth and a brief report on early progress both appeared in 1969
CISI	the information uses and needs of social scientists an overview of infross when infross began in the autumn of 1967 although a large number of studies had been conducted into the requirements of scientists for information very little had been done in the field of social science information there are a number of possible reasons for this social scientists faced with a much smaller total volume of information were much less information conscious and less inclined to seek for solutions there are very few specialist libraries in the social sciences and few librarians were therefore confronted with social scientists information needs in the same way as librarians in scientific libraries were confronted with users and their problems finally until osti came along there was little in the way of funds to support this kind of research this almost total absence of previous research had its disadvantages and advantages there were very few clues to guide us and we were therefore working to a certain extent in the dark on the other hand we had a clean and open field uncorrupted by confusing and non comparable studies there is something to be said for being one of the first in a field
CISI	sdi some economic and organizational aspects in the context of the present symposium it would seem appropriate that i should deal specifically with the economic aspects of selective dissemination of information sdi operation and use in my opinion the technical feasibility and merits of sdi have been adequately demonstrated the main barriers hindering general use however tend to be of an economic nature at shell research in sittingbourne we have been operating since 1967 an sdi service for the research staff and it has grown rapidly particularly since we started to use the ca condensates tapes early in 1969 in addition to these tapes we are currently using the ba previews tapes agdoc tapes prepared by ourselves using punched card input received from derwent and on an experimental basis toxitapes produced by biosis philadelphia all these tapes are searched locally involving the running of around five hundred profiles weekly
CISI	the theoretical foundation of the idc system six postulates for information retrieval successful delegated searching for publications relevant to the topic of an inquirer obeys rules whose relations to thermodynamics are unmistakable by the continuous growth of a documentation system in the physical and conceptual respect steadily increasing demands are made on the degree of order which prevails in the system or can be established at the specific request of an inquirer if the order in a system cannot keep pace with the increasing requirements its working capability will continuously decrease because the searcher is becoming more and more overburdened in relation to his available search time search patience and search memory the degree of order attainable in a growing literature collection can be estimated on the basis of six postulates the better the requirements imposed by these postulates are approximated in a practical documentation system the higher are its working capability and life expectancy but the expenditure to be made on the literature analyses must also inevitably be higher the establishment of these postulates originated from practical experience with the idc system and its precursors these postulates form the basis of this system and of its further development
CISI	the future of scientific and technological publications i am sure you do not need reminding of the flood of scientific information that is available today and the estimates of its growth in the next two decades in 1967 olaf helmer then senior mathematician at the rand corporation forecast that scientists and engineers would increase from five million in 1967 to twenty five million by the year 2000 and their total productivity would go up by a factor of ten he declined to assess the associated growth of and need for scientific information but merely stated that there would be substantial changes in the way in which science would actually be transacted it is these substantial changes that concern the publisher editor information scientist and librarian because if we do not anticipate   or at least keep pace with these changes   then we will not be able to meet the information needs of our readers and we will become redundant scientific information is a growing industry and it would be ironic if we could not survive amid an abundance of information i regard the chance to do something about the flow of information as a response to opportunity not as an act of desperation the big problem is to sort out what is pertinent among this information and in this world of rapid change select and develop the technological devices that will match the needs of the scientist to this mass of information
CISI	rationalization of serial holdings in special libraries this paper describes progress which has been made toward the development of a procedural model intended as a code of good practice to enable special librarians to effect economies in their journal holdings by systematically planned use of the bll a theoretical model suggested by b c brookes was tested on various sets of usage data from seven special libraries but the results proved to be unrealistic in terms of immediate provision to the user a new experimental approach has now been developed based on the total use versus total cost of a journal collection
CISI	aspects of the theory of syntax the idea that a language is based on a system of rules determining the interpretation of its infinitely many sentences is by no means novel well over a century ago it was expressed with reasonable clarity by wilhelm von humboldt in his famous but rarely studied introduction to general linguistics humboldt 1836 his view that a language makes infinite use of finite means and that its grammar must describe the processes that make this possible is furthermore a outgrowth of a persistent concern within rationalistic philosophy of language and mind with this creative aspect of language use for discussion see chomsky 1964 forthcoming what is more it seems that even paninis grammar can be interpreted as a fragment of such a generative grammar in essentially the contemporary sense of this term this monograph is an exploratory study of various problems that have arisen in the course of work on transformational grammar which is presupposed throughout as a general framework for the discussion what is at issue here is precisely how this theory should be formulated this study deals then with questions that are at the border of research in transformational grammar for some definite answers will be proposed but more often the discussion will merely raise issues and consider possible approaches to them without reaching any definite conclusions
CISI	the assault on privacy the genesis of this book can be traced to a telephone call i received during the fall of 1966 from dr james g miller then director of the university of michigans mental health institute and currently vice president for academic affairs of cleveland state university he asked what i am sure he thought was a relatively straightforward and easily answered question what are the legal consequences of computerizing copyrighted materials on closer inquiry i discovered that dr miller was exploring the possibility of using computer technology to develop a national multi media information network that would electronically integrate our colleges and universities eventually providing each of them a comprehensive and easily accessible pool of scholarly works and educational services he subsequently sought to breathe life into this idea of promoting the formation of an organization called the interuniversity communications council educom
CISI	an assessment of quality in graduate education before this study was begun in the spring of 1964 serious deliberation was given to the question of american council of education sponsorship of an evaluation of selected graduate programs of major universities that comprise an important segment of the councils membership there was never any question about the need for doing in a systematic and objective way what necessarily goes on continually in any event though usually in a piecemeal and more impressionistic way our commission on plans and objectives for higher education and other leading educators consulted concluded that a thoroughgoing study should be made and that the councils aegis was a suitable one
CISI	the association of american library schools 1915 1968 an analytical history the growth of professions has been one of the sociological phenomena of the past century as the strength of national professional associations of practitioners has increased concern with education for the professions has prompted schools to develop standards and curricula to support the preparation of practitioners during the half century spanning 1900 the schools in many professions formed national associations the association of american medical colleges for example was established in 1876 other professional school associations followed engineering 1893 law 1900 librarianship 1915 theology 1918 and social work 1919 these associations to cite a few have developed in different ways while conforming to general patterns and have reached various lvels of influence in affecting professional education
CISI	as we may think as director of the office of scientific research and development dr vannevar bush has coordinated the activities of some six thousand leading american scientists in the application of science to warfare in this significant article he holds up an incentive for scientists when the fighting has ceased he urges that men of science should then turn to the massive task of making more accessible our bewildering store of knowledge for years inventions have extended mans physical powers rather than the powers of his mind trip hammers that multiply the fists microscopes that sharpen the eye and engines of destruction and detection are new results but not the end results of modern science now says dr bush instruments are at hand which if properly developed will give man access to and command over the inherited knowledge of the ages the perfection of these pacific instruments should be the first objective of our scientists as they emerge from their war work like emersons famous address of 1837 on the american scholar this paper by dr bush calls for a new relationship between thinking man and the sum of our knowledge   the editor
CISI	authoritarian personality this is a book about social discrimination but its purpose is not simply to add a few more empirical findings to an already extensive body of information the central theme of the work is a relatively new concept   the rise of an anthropological species we call the authoritarian type of man in contrast to the bigot of the older style he seems to combine the ideas and skills which are typical of a highly industrialized society with irrational or anti rational beliefs he is at the same time enlightened and superstitious proud to be an individualist and in constant fear of not being like all the others jealous of his independence and inclined to submit blindly to power and authority the character structure which comprises these conflicting trends has already attracted the attention of modern philosophers and political thinkers this book approaches the problem with the means of socio psychological research
CISI	automated language processing the idea for automated language processing was suggested in 1964 at a time when the research efforts in information storage and retrieval were expanding at system development corporation many people in the company were directly interested in this area and an even larger group had interests that were tangentially related a quick and effective means of acquainting them with the state of the art was needed but no convenient compilation of relevant material was available it was agreed that a book on the theory and techniques of information storage and retrieval procedures would be a worthwhile project for the language processing staff to undertake although no one member could reasonably be expected to cover the entire range of technical developments in this field the staff as a whole is concerned with most phases of the work this is attested by the fact that all but one of the chapter authors were connected with sdc either as employees or consultants the single exception is pendergraft for sdc has had no sustained project in machine translation sdc management was enthusiastic in its support of the new project
CISI	automatic information organization and retrieval information retrieval is a field concerned with the structure analysis organization storage searching and retrieval of information this book deals with the computer processing of large information files with special emphasis on automatic text handling methods described in particular are procedures for dictionary construction and dictionary look up statistical and syntactic language analysis methods information search and matching procedures automatic information dissemination systems and methods for user interaction with the mechanized system as such the text includes elements of linguistics mathematics and computer programming
CISI	automated keyword classification for information retrieval this book is primarily a research monograph in which the discussion of the main topics has been broadened so that they are related to their surrounding context in information retrieval as a whole it is not a textbook and no attempt has therefore been made to justify the choice of topic or account for the use of certain concepts or to provide an elementary description of either for instance in chapter 1 it is assumed that the reader is familiar with the idea of using keywords in information retrieval i have not considered the relation between this kind of retrieval device and a controlled thesaurus or descriptor set or that between the use of simple class lists as document descriptions and the use of descriptions with a syntactic structure for example equally in chapter 2 i have made use of recall precision ratios as a means of characterising retrieval performance without justification or argument but this does not mean that i am unaware of the difficulties of doing this or of the attention which has been devoted to and controversy which has raged round this subject it is simply that from the point of view of my main purpose it is reasonable to use these ratios
CISI	automation in libraries my purpose in writing this book has been to try to give an understanding of what automated systems can do in libraries today i have limited myself strictly to those areas which are commonly termed library housekeeping   the processes of book ordering and cataloguing periodicals accessioning and circulation control whose purpose is to make a library into an efficient machine for acquiring storing and disseminating knowledge and information these are the processes which can be automated here and now to improve the quality of service which a library can give to its readers i hope that the descriptions and explanations given here will be of assistance to librarians in developing appropriate automated systems in their own libraries
CISI	the automation survey background and conclusions during the past decade the library of congress in common with many other research libraries has become increasingly aware of pressures and strains in many of its operations these areas of concern well known to librarians include mounting arrearages in cataloguing and other processing activities increasing complexity of manual inventory control files increasing difficulty in keeping card catalogues reasonably current and accurate and increasing demands for a wide variety of services for a clientele whose needs for information have grown tremendously since world war ii and many of whom have only recently turned to large research libraries for help five years ago an internal committee of the library of congress was charged to study potential applications of electronic data processing equipment to library procedures subsequently representatives of three computer firms made brief studies of library operations which intimated that certain areas could benefit substantially by automation
CISI	automatic information organization and retrieval this book deals with the computer processing of large information files with special emphasis on automatic text handling methods described in particular are procedures for dictionary construction and dictionary look up statistical and syntactic language analysis methods information search and matching procedures automatic information dissemination systems and methods for user interaction with the mechanized system as such the text includes elements of linguistics mathematics and computer programming
CISI	automated information retrieval systems irs it is easiest of all to apply mechanization and automation to the transmission accumulation and search of information automation can also be extended to cover some more complicated functions in all of these cases the results supplied by automatic devices are analysed and decisions are taken usually by man thus the role of machine is to considerably extend mans capabilities rather than to completely replace man the automated systems intended to accumulate and search for information have come to be called information retrieval systems irs these systems can also perform the simpler forms of data processing the physical facilities of these systems are communications equipment punched card computers microfilming equipment and electronic computers the latter playing the most prominent part
CISI	medical school library statistics at the june 1962 convention of the medical library association in chicago illinois mr stanley truelson now librarian of the university of rochester school of medicine and dentistry circulated a petition requesting the collection and publication of medical school library statistics forty eight medical school head librarians signed the petition indicating their approval and a committee for this purpose was formed by dr vilma proctor chairman of the medical school libraries group of the medical library association this committee composed of mr truelson dr proctor and myself studied the questionnaires already in use such as that of the u s office of education these were rejected as not meeting the needs of our specialized group of libraries as a guide for selecting the terminology in the questionnaire we used the american library associations definitions for library statistics a preliminary draft chicago 1961 after several drafts a sample questionnaire was approved by the committee and distributed to all the medical school libraries in the united states and canada the canadian medical school libraries were included as a result of communications with miss doreen fraser librarian of the bio medical library of the university of british columbia and dr j wendell mcleod of the association of canadian medical colleges
CISI	the contemporary medical society library four hundred sixty eight medical societies in the united states were surveyed to determine those which sponsor libraries seventy eight libraries were identified of which eighteen are marginal and nine are jointly supported by a medical school and a society leaving fifty one relatively substantial libraries whose major support is through society membership characteristics measured include size of collection types of media staff budget services and sources of support questions are raised concerning the role of the medical library as one institution which participates in the continuing education of the physician
CISI	analysis of one years circulation at the downstate medical center library a survey of the circulation of books and journals at the downstate medical center library was conducted based on cancelled circulation cards accumulated during a one year period analysis of the results shows the frequency of use of various materials by several groups of borrowers and brings out important differences between circulation of books and that of journals one of the result was the compilation of a list of most frequently used journals the findings are graphically represented by several tables and charts
CISI	how biomedical investigators use library books relatively few studies have been concerned with the use of biomedical books this paper reports an investigation into use made of library books by biomedical investigators based on cancelled charge slips collected at the yale medical library circulation desk telephone appointments were made to interview those research investigators whose books has been returned the previous day the interviewer obtained answers from the investigator to a questionnaire to discover how the investigator had learned of a book if the book had been useful and if useful how it had been used during the six month study period 30 4 percent of researchers volumes returned were monographs almost four fifths of books borrowed supplied information wanted and about four fifths of books used had been printed in the previous decade nine tenths of the use of books was research related the other tenth being for lecture preparation
CISI	an investigation of the educational needs of health sciences library manpower i definition of the manpower problem and research desing in order to plan adequately for education in health science librarianship and to be able to project future demands and needs we need to know a great deal more about existing manpower in health science libraries this paper the first in a series of reports on an investigation to gather this data discusses the research methodology and the development of an inventory of the institution program population upon which the survey is based an analysis in terms of geographic location type educational research etc administrative control and primary cognate area of these institutions is presented and their distribution through the various regional medical library areas is noted preliminary estimates are made based on questionnaire to the libraries on the size of the library population their relationship to reporting programs or institutions exclusive of the hospital population which is being covered in an independent survey a questionnaire to library personnel is underway which will establish along with the other questionnaires a basis for exploring the relationships which exist between institutions or programs libraries and manpower
CISI	an investigation of the educational needs of health science library manpower ii health related institutions and their library resources as part of an investigation of health sciences library manpower the universe of health related institutions and programs excluding hospitals was surveyed by postcard questionnaire to produce an inventory and description of libraries providing services to these institutions reported access to library resources indicating usage of some 2 207 non hospital libraries eighty percent 2 431 of the institutions reported that the library used was within their own institution 20 percent 608 noted that the library was outside of their institution the distribution of health related institutions and libraries is shown by rml districts together with relevant census data a classification of libraries based on the degree of involvement of the libraries facilities resources and personnel in supplying services to health related institutions was developed it is concluded that projections of manpower needs should take into account institutions and programs not at present possessing health sciences libraries as well as documented demand in existing health sciences libraries
CISI	an investigation of the educational needs of health sciences library manpower iii manpower supply and demand in health sciences libraries an investigation of the manpower requirements of health sciences libraries and of educational programs appropriate to these manpower needs was begun in march 1968 to data 4 727 libraries have been identified as being used by 14 000 health sciences institutions and programs of this total 2 628 are hospital libraries 1 328 are health sciences libraries and 771 are academic or public libraries within these libraries some 14 938 persons are directly involved either full  or part time in the delivery of health sciences library services of the total work force 5 861 persons are employed in hospital libraries and 9 077 are employed in health sciences libraries and collections the ratio between professional and nonprofessional employees is 1 2 professional and nonprofessional status was assigned by the chief librarian survey data indicate a 7 percent manpower shortage in positions classified as professional and a 3 percent shortage in positions classified as nonprofessional
CISI	an investigation of the educational needs of health sciences library manpower iv characteristics of manpower in health sciences libraries a statistical description based on a mail survey of personnel in 2 099 health sciences libraries located outside of the hospital setting is reported respondents to the survey were divided into three groups professionals those possessing a graduate library degree nonprofessionals those not possessing graduate library degree and chief librarians those responsible for a librarys operations survey items dealt with education sex age salary job mobility and preference for continuing education programs some 60 percent of the respondents were professionals 40 percent were nonprofessionals seven hundred and twenty eight chief librarians were identified in the population 57 percent were professional librarians while the remainder were without a graduate library degree approximately 1 5 of all survey respondents were men the age distribution for the work force tended to be bimodal reflecting the career patterns of women and the later entry of men into librarianship the annual salary for male professionals was calculated at 12 732 for female professionals at 10 044 for male nonprofessionals at 7 878 and for female nonprofessionals at 6 313 male professionals were found to have the highest rates of job and geographic mobility conversely female nonprofessionals were lowest in mobility in expressing a preference for continuing education programs in library science professionals tended to request courses dealing with the organization of libraries health sciences institutions and their relationships while nonprofessionals inclined towards courses in technical processing
CISI	selected list of books and journals for the small medical library this updated list of 410 books and 136 journals is intended as a selection aid for the small library of a hospital medical society clinic or similar organization books and journals are arranged by subject with the books followed by an author index and the journals by an alphabetical title listing items suggested for first purchase by smaller libraries are noted by an asterisk to purchase the entire collection of books and to pay for the annual subscription costs of all the journals would require an expenditure of about 12 000 to acquire only those items suggested for first purchase approximately 3 250 would be needed
CISI	medline evaluation study medline medlars on line is the new on line interactive bibliographic searching system which was recently developed by the national library of medicine the system provides users with lists of bibliographical citations and other information from a three year file of over 1 250 biomedical journals a survey testing user reactions was conducted at the university of virginia medical library the results of the survey are based on replies by 246 users who requested one or more medline searches between september 1972 and march 1973 the findings indicate that over 93 believe that medline is a substantial improvement over the traditional methods of searching through the printed indexes these respondents also stated that the results of medline searches had assisted them in their clinical or research work or both asked whether they would continue to use medline after the imposition of user charges on july 1 1973 about 75 said that they would the remaining 25 expressed some reservation and doubts the survey gives reason to believe that with the imposition of user charges the use of medline will decline
CISI	medlearn an orientation to medline medlearn an orientation to medline was developed to educate members of the biomedical community to become competent on line searchers it appears in two complementary forms an interactive terminal presentation available on the tymshare network and a supporting hard copy manual which contains the didactic portions of the computer program as well as additional items which are not suitable for on line presentation medlearn a flexible instruction tool is divided into forty sections which may be selected in various sequences depending on the users previous experience two medline simulations and feedback sections after practice on medline provide motivation for continued learning the orientation program was evaluated at several medical centers with uniformly favorable results
CISI	a cooperative serial acquisition program thoughts on a response to mounting fiscal pressures a regionally cooperative method of distributing responsibility for every serial title in a region is outlined the system assures the equitable distribution of the number of titles for which each library is committed later refinements suggest an equalization of cost commitments on the basis of fiscal resources available for serial purchases it is pointed out that fiscal realities will force some sort of serial acquisition cooperation for all viable medical libraries
CISI	use of medical and biological journals in the yale medical library this paper presents data for the end of 1960 on recorded use of some two hundred of the most often used scientific and medical journals in the yale medical library the investigation was designed to identify the most abundantly used titles of recent date of publication to guide the acquisition of multiple subscriptions at the same time data was collected to distinguish heavily used back sets
CISI	the evaluation of published indexes and abstract journals criteria and possible procedures this paper describes possible criteria by which the effectiveness of a published index may be evaluated and suggest procedures that might be used to conduct an evaluation of a published index the procedures were developed for the national library of medicine and relate specifically to the recurring bibliographies produced by medlars in various specialized areas of biomedicine the methods described should however be applicable to other printed indexes and abstract journals factors affecting the performance of a published index are also discussed and some research projects relevant to the evaluation of published indexes are reviewed
CISI	world biomedical journals 1951 60 a study of the relative significance of 1 388 titles indexed in current list of medical literature this study is an application of the relationship of serial articles published to serial articles cited developed in theory in the authors statistical bibliography in the health sciences bulletin 50 450 461 july 1962 a ranked list of the indexes of significance of most of the serials indexed in current list of medical literature was derived and erected from 21 000 citations secured in a random sampling of 1962 and 1961 biomedical journals regularly received in the yale medical library the author measures the gross indexing effectiveness of current list against his indexes of significance offers his method and results as means to reach objective standards for indexing and abstracting and projects his results as measures of general value of the serials analyzed
CISI	basic journal list for small hospital libraries this basic journal list of forty eight journal titles is intended as a selection guide for the librarian of the small hospitals it is based on a survey of physicians in virginia who were asked to review journal titles contained in the 1967 edition of a list compiled by mr alfred n brandon the list is designed for the library in a hospital of from 100 to 300 beds and for the active clinician
CISI	aim twx service at the university of virginia a review and evaluation the paper reviews the highlights of a four week trial period november 19   december 18 1970 during which the medical library of the university of virginia experimented with a new remote access bibliographical control and retrieval system via its twx machine the system called aim twx was sponsored by the lister hill national center for biomedical communications and utilized a time shared ibm 360 67 computer in santa monica california citations from 109 clinically oriented journals from 1966 to date including those currently included in the abridged index medicus may be retrieved either on  or off line various aspects of this service are described including problems of staffing training and record keeping as well as the role of the mesh vocabulary which is the principle language of the man computer dialog the statistical results indicated that the system was used for approximately 200 minuted on nineteen days and that an average of sixteen searches were run on any given day or about 4 6 searches per hour of use in spite of an inexperienced staff who had little knowledge of the mesh vocabulary and whose training schedule was limited to one four hour session the experiment was highly successful in terms of searches and citations at the end of the period 298 searches had been run for 114 requestors and 5 343 citations had been produced only fifty five searches yielded no citations the experiment generated a great deal of excitement and interest among the staff of the library and of the medical center moreover a large number of medical practitioners in large and small communities of virginia participated in this experiment indicating that there exists a great demand for this type of literature searching which aim twx is able to provide with great rapidity
CISI	choosing physiology journals for many years administrators of library collections have sought objective criteria for assembling well rounded periodical collections in the subject fields represented by their collections the nearest approach to any criterion which does away with the a priori knowledge of the specialist was first suggested by gross and gross in 1927 this method consists essentially of counting the bibliographic citations at the conclusions of the articles in a basic periodical of the field under consideration and of arranging the journals cited in order of the frequency of their citation thus in the field of chemistry the references in the journal of the american chemical society are counted and a list is made of the most frequently cited journals according to gross and gross the journals which are cited most frequently in the journal of the american chemical society are the most valuable journals for a library to purchase in order to possess a well rounded collection in chemistry although the gross and gross method has been in use for almost twenty years the fundamental assumptions upon which the method is based have never been examined these assumptions are 1 the value of a periodical to a professional worker is in direct proportion to the number of times it is cited in the professional literature 2 the journal or journals used as the base for the tabulation are representative of the entire field 3 if more than one journal is used as a base all of them can be weighted equally
CISI	statistical bibliography in the health sciences the sustained interest in documentation as a key to the retrieval of information in the literature of the sciences has obscured largely the potential utility of statistical bibliography as a method of analyzing information needs in the belief that a discussion of the latter may be of value to interested biomedical librarians and scientists a review of investigative methods and results in the health sciences is offered here statistical bibliography may be defined as the assembling and interpretation of statistics relating to books and periodicals it may be used in a variety of situations for an almost unlimited number of measurements within the last forty years bibliographical statistics have been collected and explained in several fields of science for these main purposes to demonstrate historical movements to determine the national or universal research use of books and journals and to ascertain in many local situations the general use of books and journals
CISI	mechanization of library procedures in the medium sized medical library mechanical means for expediting library work have been considered for many years as an examination of the early pages of library journals bears out the very first volume of the forerunner of the bulletin the medical library and historical journal moreover contained an article on the use of the typewriting machine in cataloging telephones have long been accepted as library machines and except for unusual items hand bookbinding has given way to machine bound books nevertheless when the term machine methods is used for libraries today the prevailing idea is that expensive and complicated electronic equipment must be employed and since few libraries are able to afford such equipment for themselves it is generally assumed that none but the largest libraries the library of congress or the national library of medicine for example will be able to employ already existing mechanical methods or devise systems specifically applicable to their own situations
CISI	moderately and heavily used biomedical journals the purpose of this investigation was to produce a title list of current journals suppling upwards of 75 percent of demand at the columbia and yale medical libraries columbia received nearly 2 000 journals and yale over 1 500 findings are based upon an analysis of canceled charge slips for issues published from 1959 through june 1962 this combined study of recorded usage for six months in the columbia medical library 12 9 percent of circulation during january through june 1962 and for one year in the yale medical library 12 5 percent of 1961 62 circulation revealed that a core of 262 journals supplied 80 percent of use of titles published in the 1959 to mid 1962 period however it is probable that current issues of all titles received were used at least once within the libraries titles of sixty seven journals which supplied slightly more than 50 percent of use are listed
CISI	medical libraries and the assessment of user needs users of information in science and technology have been studied in great detail with respect to material read amount of time spent in reading and searching the literature categories of questions asked an so on probing for this information has been undertaken by means of structured and unstructured interviews diaries surveys and questionnaires although a large amount of data has emerged on information usage and flow the subjective response of scientists furnishes comment only on the satisfaction produced by present information services and does not yield insight into the extent to which needs remain unsatisfied relevance figures based upon the response of systems to questions cannot be equated with satisfaction of needs since questions constitute in most cases inadequate representations of underlying information needs assessment of the needs of users of medical libraries and information system must in fact be made in relation to the observed behavior and experience of biomedical scientists there is room for well designed experimentation which can explore the interaction of both psychological and environmental factors significant differences in information needs exist among and between individuals such as researches and clinicians in the same environment with respect to environment it is hypothesized that the information needs for medical practitioners in remote areas might differ significantly from those of their colleagues working in large metropolitan centers in close proximity to medical schools research institutions and other rich sources of information fallout it is anticipated that experimentation will eventually result in a methodology which will permit the determination and prediction of the information needs of any identified groups of users in a specific environment
CISI	analysis of recorded biomedical book and journal use in the yale medical library part i date and subject relations analysis of book and journal circulation is based on cancelled charge slips collected over a one year period in the yale medical library about two fifths of material circulated were monographs books and journals in seven subject fields provided over half of the circulation approximately two thirds of both books and journals used had been published during the most recent nine years a subject by subject examination of the ratio of books to journals circulating revealed that in subject where proportionally more journals than books were taken out of the library books were of more recent imprint dates than were journals contrary to the overall pattern date distribution of books and journals by subject was also studied results are illustrated with graphs and tables
CISI	analysis of recorded biomedical book and journal use in the yale medical library part ii subject and user relations cancelled charge slips collected over a one year period supply the data for this analysis of circulation in the yale medical library full time teacher faculty are the heaviest users of journal literature and students of monograph literature faculties of medical school departments are compared in terms of their use of material in individual subjects subject literatures are analyzed in terms of groups of users borrowing from them the extent to which journal titles used by medical students are also used by medical school faculty is examined one of the products of the study is a rank list of journal titles used in the library results are presented in several tables
CISI	the circulation analysis of serial use numbers game or key to service the conventionally erected and reported circulation analysis of serial use in the individual and the feeder library is found to be statistically invalid and misleading since it measures neither the intellectual use of the serials contents nor the physical handlings or serial units and is nonrepresentative of the in depth library use of serials it fails utterly to report or even to suggest the relation of intralibrary and interlibrary serial resources the actual mechanics of the serial use analysis and the active variables in the library situation which affect serial use are demonstrated in a simulated analysis and are explained at length a positive design is offered for the objective gathering and reporting of data on the local intellectual use and physical handling of serials and the relating of resources data gathering in the feeder library and implications for the extension of the feeder librarys resources are discussed
CISI	development of methodologic tools for planning and managing library services i project goals and approach in july 1966 the institute for advancement of medical communication began work on a project aimed at developing methods for collecting objective data suitable for planning and guiding local regional and national programs to improve biomedical libraries and the biomedical information complex this article constitutes an introduction to a series of reports on the methodologic tools that have been developed it describes the overall purpose and initial goals of the project gives the general plan of the work and presents five basic concepts that underlie the projects approach and structure the entire effort
CISI	development of methodologic tools for planning and managing library services ii measuring a librarys capability for providing documents a method of measuring a librarys capability for providing the documents its users need has been developed the library is tested with representative sample of such documents to determine how long would be required for users to obtain these documents test results are expressed in terms of a capability index which has a maximal value of 100 only if all the sample documents are found on shelf specific tests employing samples of 300 documents have been developed that are appropriate for academic an for reservoir biomedical libraries realistic field trials have demonstrated that these two tests are practical to administer and that test results are adequately reproducible when strict comparability is not important a library can test itself in assessing a reservoir library test results are supplemented by data on its typical processing time for interlibrary loan requests currently these tests are being used in a national survey the general method is applicable to other types of libraries provided appropriate test samples are established if their limitations are clearly understood these document delivery tests can be valuable tools for planning and managing library services
CISI	development of methodologic tools for planning and managing library services iii standardized inventories of library services a standardized procedure was developed for eliciting those details for a librarys service policies that are important to its users and for recording the data by checking appropriate categories on a form this inventory procedure covers the entire spectrum of user services and accommodates a wide range of policies the inventory was originally designed for use by trained interviewers in large scale surveys of academic medical libraries however it is also suitable for other kinds of libraries and the interview guide and checklist can be used for a self survey by library stuff in addition to survey use the inventory has a variety of educational administrative managerial and research applications a methods for weighting the categorical inventory data to reflect the relative desirability of different policies makes it possible to calculate scores indicating how a librarys policies compare with those of an optimal library an analogous inventory of the services a library provides to other libraries was developed for surveying major backup resources in the medical library system
CISI	survey of the card catalog in medical libraries a survey of present uses and arrangement of medical library card catalogs was made in order to determine current practices and trends attention was focused on the influences of mesh on the card catalog the results indicate that the prevalent type of card catalog found in medical libraries is the divided catalog in addition it appears that this catalog arrangement is gaining acceptance and the trend is toward division mesh has an effect on the organization of the card catalog libraries indicate that it is an influential factor in the decision to divide the catalog
CISI	survey of medical literature borrowed from the national lending library for science and technology this paper reports the results of a four week questionnaire survey carried out at the national lending library n l l great britian to discover which types of organizations were the principal users of medical literature what types of literature were used and which were the main sources of references to medical publications industrial organizations and universities accounted for the majority 62 percent of the loans most of which were english language periodicals published since 1960 for the whole sample citation list in periodical articles were the principal sources of references although for literature published in the last fifteen months abstracting and indexing journals were the main sources of the latter index medicus proved to be the most fruitful source of references by asking whether the item requested was really useful to their work a measure of the reliability of the different sources of references was obtained appendixes include the questionnaire a list of the most frequently borrowed journals and a list of abstracting and indexing journals used as sources of references
CISI	a regional medical library network the raison detre for cooperative networks is discussed and the development of the suny biomedical communication network is traces briefly a description of the system and its products is given the cooperative cataloging program engaged in with the francis a countway library of medicine and the national library of medicine is described as are the efforts of the network in the production of regional and state wide union lists of serials
CISI	thesaural problems in an on line system this paper describes the construction of a synonym thesaurus or entry vocabulary for the suny biomedical communication network which will permit the user greater ease of access to mesh indexed material without previously consulting a printed list of indexed terms in order to discover the actual terminalogy used by a researcher words were extracted from titles of articles appearing in index medicus and compared with the subject heading under which they appeared as well as strict synonyms grammatical variants were also included work is continuing on relating other indexing vocabularies such as excerpta medica and current medical terminalogy used in the biomedical world to mesh terms
CISI	the role of the medical librarian in sdi systems many ongoing selective dissemination systems designers assume that the librarian can be omitted from active participation in execution of the master plan isis four years of experience with asca service have shown that librarians must be an integral part of the system and engage in a active dialogue between users and the machine specific examples of how librarians can best serve the information needs of scientists using sdi systems are examined it is the basic contention of this paper that the librarian should serve as an intermediary between users and the numerous new information media in this manner the librarian can filter and translate the requirements of individual scientists to conform with the inherent limitations of all machine systems while exploiting their capabilities to the fullest
CISI	library participation in a biomedical communication and information network the experience of two libraries participating in the suny biomedical communication network is described the history of the network if briefly given together with its original aims and their current status use of the terminals and formulation of queries are explained figures are given for total costs number of searches performed and cost per search there is a account of the internal structure of the administration of the network
CISI	selected reference aids for small medical libraries this annotated list of 178 items is compiled as a guide to the development of the reference collection in a small medical library arrangement following the pattern of the previous revision is by broad subject groups titles are chiefly in english textbooks in subject fields have been omitted since these are covered adequately in several comprehensive guides to the literature
CISI	coordination of regional libraries with regional medical program projects the medical library assistance act authorized the regional medical library program to improve information services in health fields as well as other programs designed to help the health worker both the rmlp and the regional medical program are based on regional cooperation to enhance the value of available resources and to enable health workers away from main centers to use them services with regional medical libraries must supply are described as this program develops more than conventional library services will be provided regional medical programs stress the continuing education of health related personnel and their need for health information libraries are necessarily involved in such programs the regions of the rmp are smaller than those of the rmlp and the smaller regional focus may be an advantage specific examples of the coordination of library services and library  oriented programs are given
CISI	user services offered by medical school libraries in 1968 results of a national survey employing new methodology the breadth and depth of services that ninety two medical school libraries offer to individual user were ascertained by interviewing the heads of these libraries employing a standardized inventory procedure developed earlier bulletin 56 380 403 oct 1968 selected aspects of the descriptive data obtained on services to faculty and to medical students are presented and commented upon comparisons with the findings of earlies surveys suggest that increases in the stuffs and budgets of medical school libraries over the past two decades have gone largely to supporting a rapidly increasing volume of service rather than to any striking increase in the breadth and depth of services to facilitate summarization and comparisons among libraries the descriptive data were weighted and converted to quantitative measures the weighting scheme was established by a group of five academic medical librarians to reflect the relative values the group assigned to different services one these quantitative measures the percentage score for overall services relative to the optimal library summarizes a library s services in a single figure on this measure medical school libraries ranged from 38 percent to 87 percent the median overall score was 63 percent results of some exploratory analysis are described these analyses attempted ti find explanations for the observed differences among libraries and among geographical regions on the quantitative measures present and potential uses of the survey data for managerial and research purposes are discussed one of the most important of these uses is in establishing and implementing standards   activities which should be carried out by the library profession itself   and recommendations are made for a program of such activities that is appropriate for the medical library association
CISI	the national biomedical communications network as a developing structure the national biomedical communications network has evolved both from a set of conceptual recommendations over the last twelve years and an accumulation of needs manifesting themselves in the requests of members of the medical community with a short history of three years this network and its developing structure have exhibited most of the stresses of technology interfacing with customer groups and of a structure attempting to build itself upon many existing fragmentary unconnected segments of a potentially viable resource  sharing capability in addition to addressing these topics the paper treats a design appropriate to any network devoted to information transfer in a special interest user community it discusses fundamentals of network design highlighting that network structure most appropriate to a national information network examples are given of cost analyses of information services and certain conjectures are offered concerning the roles of national networks
CISI	selected lists of journals for the small medical library a comparative analysis the results of a survey and weighted summary of all major suggested journal subscription lists for hospital libraries are described a total of ninety one titles taken from 225 titles examined is listed under thirty three subject headings contrasts are made for the titles and subject headings employed by others and the potential of stearns core collection concept for small medical libraries is dealt with in detail
CISI	the medical library assistance act an analysis of the nlm extramural programs 1965 1970 the imbalance between medical library resources and information needs of the health professional led to a reexamination of the mandate for the national library of medicine legislation known as the medical library assistance act mlaa was passed in 1965 which enabled the nlm to 1 initiate programs to assist the nations medical libraries and 2 develop a medical library network with the establishment of regional medical libraries to link the nlm with local institutions the national library of medicine through the mlaa has made available 40 8 million to the medical library community under a competitive grant and contract mechanism for the period july 1965   june 1970 a total of 604 projects has been executed in resources research and development training construction regional medical libraries publications and special scientific projects an assessment is given of each of these programs and their impact on both the national library of medicine and individual medical libraries in the aggregate these programs have significantly improved library and information services to the professional health user the principal limitation has been inadequate funding to accomplish the level of originally stated objectives
CISI	a bookshelf in public health medical care and allied fields this bibliography of nonserial publications consists of 610 annotations it is intended as a guide to the development of a collection for librarians and for health professionals in research and education references are mostly to publications from 1960 titles are in english both primary and secondary sources are cited
CISI	review of criteria used to measure library effectiveness this article reports the results of survey of literature on measures of library effectiveness this survey led to the formulation of six criterion concepts accessibility cost user satisfaction response time cost benefit ratio and use the advantages and disadvantages of each method of measurement are discussed several points which became clear during the analysis are discussed first there is a relative lack of concern with the rationale behind the evaluation process although the results invariably lead to a confused interpretation when there is no clear understanding of the purpose of an evaluation second the total library system is rarely considered instead each evaluation criterion is taken in isolation rather than as part of the whole third the librarys preservation function has not been considered at all
CISI	document delivery capabilities of major biomedical libraries in 1968 results of a national survey employing standardized tests the standardized document delivery tests ddts developed earlier bulletin 56 241 267 july 1968 were employed to assess the capability of ninety two medical school libraries for meeting the document needs of biomedical researchers and the capability of fifteen major resource libraries for filling i l requests from biomedical libraries the primary test data are summarized as statistics on the observed availability status of the 300 plus documents in the test samples and as measures expressing capability as a function of the mean time that would be required for users to obtain test sample documents a mathematical model is developed in which the virtual capability of a library as seen by its users equals the algebraic sum of the basic capability afforded by its holdings the combined losses attributable to use of its collection processing relative inaccessibility and housekeeping problems and the gain realized by coupling with other resources i l borrowing for a particular library or group of libraries empirical values for each of these variables can be calculated easily from the capability measures and the status statistics regression equations are derived that provide useful predictions of basic capability from collection size the most important result of this work is that cost effectiveness analyses can now be used as practical decision aids in managing a basic library service a program of periodic surveys and further development of ddts is recommended as appropriate for the medical library association
CISI	the implementation evaluation and refinement of a manual sdi service the missouri institute of psychiatry library has implemented an inexpensive manual sdi selective dissemination of information service based upon the monthly issues of index medicus the implementation and refinement of the system are documented and the very favorable response to the system is examined the sdi service is compared to current contents with the finding that 60 percent of the sdi participants prefer it to current contents for this select portion of researchers the index medicus sdi is the more suitable mode of current awareness for a significant portion of the mip staff however the score of index medicus is too restricted to suitable replace current contents all sdi users find it highly acceptable curent awareness service for use in addition to current contents and have indicated the desire to continue participation in the service
CISI	a method of estimating the in house use of the periodical collection in the university of minnesota bio medical library during two one week periods in april 1972 information on periodical title and date was gathered from periodicals collected from study and reshelving tables of the university of minnesota bio medical library it was determined that 1 a few titles accounted for most of the total use 2 the relationship between age and amount of use of a journal may be described by the equation y ke  bx and 3 the last five years of publication accounted for 58 of the total use
CISI	a behavioral approach to historical analysis to issue a clarion call for historians to adopt a behavioral approach to their subject may seem as up to date and exciting as last months newspaper for it is the academic fashion today to argue the utility of social science theory in the writing of history books and articles issue forth from the presses in seeming profusion advocating and even occasionally demonstrating such an approach yet these many pages fail in three significant ways to accomplish the end they nominally espouse and which i urge
CISI	a behavioral theory of the firm this book is about the business firm and the way it makes economic decisions we propose to make detailed observations of the procedures by which firms make decisions and to use these observations as a basis for a theory of decision making within business organizations our articles of faith are simple we believe that in order to understand contemporary economic decision making we need to supplement the study of market factors with an examination of the internal operation of the firm   to study the effects of organizational structure and conventional practice on the development of goals the formation of expectations and the execution of choices
CISI	a mathematical theory of communication the recent development of various methods of modulation such as pcm and ppm which exchange bandwidth for signal to noise ratio has intensified the interest in a general theory of communication a basis for such a theory is contained in the important papers of nyquist and hartley on this subject in the present paper we will extend the theory to include a number of new factors in particular the effect of noise in the channel and the savings possible due to the statistical structure of the original message and due to the nature of the final destination of the information the fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point frequently the messages have meaning that is they refer to or are correlated according to some system with certain physical or conceptual entities these semantic aspects of communication are irrelevant to the engineering problem the significant aspect is that the actual message is one selected from a set of possible messages the system must be designed to operate for each possible selection not just the one which will actually be chosen since this is unknown at the time of design
CISI	a mathematical theory of communication in this final installment of the paper we consider the case where the signals or the messages or both are continuously variable in contrast with the discrete nature assumed until now to a considerable extent the continuous case can be obtained through a limiting process from the discrete case by dividing the continuum of messages and signals into a large but finite number of small regions and calculating the various parameters involved on a discrete basis as the size of the regions is decreased these parameters in general approach as limits the proper values for the continuous case there are however a few new effects that appear and also a general change of emphasis in the direction of specialization of the general results to particular cases we will not attempt in the continuous case to obtain our results with the greatest generality or with the extreme rigor of pure mathematics since this would involve a great deal of abstract measure theory and would obscure the main thread of the analysis a preliminary study however indicates that the theory can be formulated in a completely axiomatic and rigorous manner which includes both the continuous and discrete cases and many others the occasional liberties taken with limiting processes in the present analysis can be justified in all cases of practical interest
CISI	between mls and phd a study of sixth year specialist programs in accredited library schools the intent of this survey is to describe educational practice to spring 1969 in the emerging sixth year specialist programs in library schools accredited by the american library association
CISI	bibliographic control of nonprint media educational systems specialists lament the deplorable lack of organization of nonprint media for utilization in the learning process audiovisual personnel have out of despair made a painful entry into the world of bibliography while librarians long experienced in the bibliographic control of printed matter still appear preoccupied with more conventional forms of information and reluctant to turn their expertise to the organization of nonprint media
CISI	bibliographic control of microforms bibliographic control of microforms is a foremost need in todays library world despite the rapidly increasing quantity of materials and their bibliographic complexity the methods for controlling microforms on all levels   local national and international   are inadequate
CISI	on a class of skew distribution functions it is the purpose of this paper to analyse a class of distribution functions that appears in a wide range of empirical data   particularly data describing sociological biological and economic phenomena its appearance is so frequent and the phenomena in which it appears so diverse that one is led to the conjecture that if these phenomena have any property in common it can only be a similarity in the structure of the underlying probability mechanisms the empirical distributions to which we shall refer specifically are a distributions of words in prose samples by their frequency of occurrence b distributions of scientists by number of papers published c distributions of cities by population d distributions of incomes by size and e distributions of biological generally by number of species
CISI	book availability and the library user the essentially logistical problem of making library books physically available when wanted by library users is central to librarianship this book is a tentative attempt to provide a treatise on this problem as such it has to deal with both theoretical analysis and the practicality of solutions no apology is made for the attention devoted to theoretical analysis because the author believes that a clear conceptual understanding of the factors involved is important for improved librarianship the fact that analytical models are not always usable does not mean that the insight that can sometimes be derived from such analyses will not lead to a better understanding of the problems and thereby to improved library services
CISI	book catalogs in the intervening years since the appearance of the first collection of papers concerning book catalogs kingery robert e and tauber maurice f book catalogs n y the scarecrow press 1963 attention has been concentrated on the book catalog as a substitute for or an auxiliary to the card catalog this selection of papers has identified some of the efforts to solve particular problems concerned with book catalogs the published papers as well as those which have been written specifically for this volume bring additional observations concerning the place of the book catalog in library services
CISI	book publishing what it is what it does we speak of book publishing as an industry and as a profession both designations are certainly appropriate book publishing is a business conducted for the most part for profit but its practitioners   at least those who do it honor   have motivations that transcend their profit interest they know that books are no mere commodity no mere items for consumption that leave their readers much as they find them books like other vehicles of information and sources of entertainment can change influence elevate demean exalt or depress those who expose themselves to them what books are and can be depends heavily on the judgement integrity taste and acumen of those who select and produce them   their publishers
CISI	book selection of censorship the key question was whether restrictions are being imposed on librarians or whether they are imposing restrictions on themselves that threaten the citizens right to easy access to as adequate a collection of books and periodicals as his community his country or his state can afford readers of this report may come to different conclusions about the right answer to this question but whether they conclude that librarians are or are not being as forceful as they might be in developing and upholding freedom to read principles it should not be forgotten that it is librarians themselves who have had the courage to provide the evidence
CISI	book selection and censorship when is a librarians decision not to include a book in his library collection an act of book selection and when is it censorship is there in fact any discernible difference in the two terms book selection and censorship this topic was discussed so lucidly and ably long ago by lester asheim in what has become a classic essay in the literature of librarianship not censorship but selection that raising it again may appear to be an exercise in redundancy
CISI	buyers and borrowers this is the second book based on studies into social aspects of book reading the present book is largely a report on work which was carried out in 1967 68 but either not analysed or written up in time for the first book or work actually carried out and analysed during the second years research the reader of this book will find it useful to have read the first book but the present book is self contained and does not require reference to the first one
CISI	books for junior college libraries the primary purpose of this publication is to serve as a book selection guide for junior and community college libraries whether long established newly established or in the planning and preinstruction stage the need for a new and authoritative book list has long been expressed by administrators faculty members and librarians it is hoped that the present list will meet this need and that it will also be useful in four year colleges with special reference to their lower division work in secondary schools especially where accelerated and honors programs or courses for advanced college placement are offered and in public libraries seeking to satisfy the demands of high school and college students
CISI	a brief guide to sources of scientific and technical information this guide is a recapitulation and refinement of the substantive content of a one and a half day course which was given before three groups of federal scientists and engineers during the fall of 1967 its purpose was to train and inform working scientists and engineers as to the most direct and efficient means of seeking and acquiring work related information the impetus for the course was the recognition of the growing need for working scientists and engineers to share and participate in the existing and emerging information tools and mechanisms and to avail themselves of the opportunities afforded by the newer approaches to information collection organization and dissemination a further related purpose of the course was to facilitate the fullest possible participation of the working scientist and engineer in the evolution of information services and mechanisms which are likely to have a greater and greater effect on his professional activities
CISI	building library collections each year thousands of books are published by the general the technical the governmental and the university presses in this and other countries from this overwhelming mass of new publications every library must within the limit of its funds select that small part which will be most beneficial to the community it serves this is properly an awesome responsibility to the young inexperienced librarian to the competent veteran it is a task which though carried on week after week never can approach the ease of a well mastered routine each book examined requires the exercise of careful judgement integrity emotional control at times and scrupulous honesty guided always by a sense of purpose
CISI	can di system user reaction to a computer and information retrieval system for canadian scientists and technologists in april 1970 the can sdi project developed by the canadian national science library completed its first year of operation at that time the project designed as a national service to alert scientists and technologists to current information in specific fields of research was serving over six hundred and fifty subscribers requiring a total of more than three thousand five hundred individual computer queries over one thousand personalized bibliographies are prepared each week from commercially available data bases purchased from chemical abstracts service the institute for scientific information isi and the british institution of electrical engineers a detailed description of the service was given in a paper by j e brown published in october 1969
CISI	case studies in library computer systems case studies in library computer systems does not follow the mode of the other volumes in this series because none of the persons libraries or systems is disguised neither has information been withheld to force readers tp explore alternative choices as in the usual case method rather all systems are identified and described as accurately as possible descriptive case studies are problem oriented however because they analyze a situation in which a librarian had to decide if a computer could be successfully utilized to solve the problem at hand the descriptive case method rather than the problem case method was chosen because it seemed important to describe each system in detail and to evaluate its performance in the context of a real library environment and against the background of particular institutional service objectives
CISI	case studies in systems analysis in a university library the marriage between the university of michigan library and community systems foundation seemed like a sensible step at the time too often library administration found it necessary to choose between alternate courses of action without having adequate information in addition overburdened department heads rarely found time to alter their systems substantially to accommodate demands on the library and their departments let alone time to make these changes in a systematic manner which considered the impact on other departments and carefully weighed alternative solutions as a consequence of this situation the library administrators were considering ways of providing staff assistance to themselves and the department heads so that alternate courses of action could be designed and properly evaluated
CISI	cataloging rules ad principles the present study was undertaken pursuant to an assignment by the library of congress the author was directed to prepare for the board on cataloging policy and research of the a l a division of cataloging and classification a general analysis of the ala cataloging rules for author and title entry with special consideration of the rules for corporate authors and a discussion of the objectives and principles which should underlie a revision of the rules the first three parts of the report are directed respectively to the three aspects of this assignment the fourth part of the report was added to deal with general questions raised by readers of a preliminary draft of this report
CISI	cataloging u s a the book deals almost entirely with theory and principles only now and then if it seems necessary to a complete understanding of the implications of theory is some detail of practice briefly described it follows that the work is not a substitute for rules of entry and description subject headings rules and lists classification schemes or other similar reference books instead it is only a commentary on such works and it does not profess to comment on more than a few of what seem to be the most important aspects of each comments are made only on cataloging in the united states many interesting practices have always been part of cataloging abroad but to write of these practices also would have taken several books this work looks at the foreign scene only when it seems necessary to understand fully some procedure in this country if a reader in some other country finds anything in this book helpful that will be i hope good for him and for his countrys cataloging i am not at all sure however that what we do and think in this country will be of value in other countries with other conditions in no sense is this a book of american intellectual imperialism
CISI	catv and its implication the papers in this publication represent the edited oral presentations of the speakers at the conference the conference theme centered on the implications of cable television for libraries the general purpose of the institute was to foster greater understanding about the subject of cable television in the conference participants more specifically the planning committee for the conference enumerated the following objectives 1 to provide an atmosphere of inquiry focused on the implications of cable television for libraries 2 to provide consultants and resource people who have knowledge and experience related to the potential of cable television and its implications for libraries 3 to expand the participants understandings and perceptions of the technology of cable television and its related equipment as they affect the libraries communications responsibilities 4 to suggest some techniques for utilizing cable television in originating local programs and to explore the possibilities for the varieties of services cable television can offer the profession 5 to aid librarians in all types of libraries to become aware of the unique possibilities for the utilization of cable television in their specific types of libraries and also to suggest the importance of cable television in a systematic approach to library and information networks and 6 to create a growing and continuing consciousness of the problems and opportunities for the utilization of cable television in libraries
CISI	centralized book processing this report summarizes the results of the fourteen month feasibility study    the colorado academic libraries book processing center project calbpc the report is organized under nine major sections i background ii participating libraries    operational characteristics iii cost analysis iv business office procedures v the book processing center vi approval plan utilization vii mathematical model simulation viii attitude survey ix conclusions and recommendations
CISI	centralized processing for academic libraries final report of the colorado academic libraries book processing center the first six months of operation this is the final report of the colorado academic libraries book processing center calbpc project the calbpc project was begun in 1965 by nine academic libraries in colorado in an effort to establish a centralized acquisition and processing center the report of phase i ii completed in june 1968 dealt primarily with a general feasibility study the design of the central system costs of acquiring and processing in nine libraries and a number of related concerns such as accounting the congruence of approval plans and user attitudes toward library services this report focuses on the experimental operations which were concluded officially on september 30 1969 whereas the phase i ii study dealt with the theory and principles upon which a system might be based we are presently concerned with the pragmatics of book processing the obstacles encountered and the solutions achieved although this report deals primarily with cooperative acquisitions and processing we believe it also contributes to a better understanding of cooperative programs the experiment was designed to monitor operations throughout the acquisition cataloging cycle performance and cost measurements were made on most internal and external aspects of the system monitoring also extended into the participating libraries where a product acceptance study was conducted a secondary objective of the project was to observe the relationships which formed between the participants and the central agency such as the interface of systems and the human interaction of participants and the center
CISI	carl h milam and the american library association carl hastings milam spent the most productive years of his life in the positions with which his name is most closely associated those of secretary and later executive secretary of the american library association ala from 1920 to 1948 when he became secretary the association had already been in existence for forty  four years what kind of association was it that claimed milams allegiance what experience had he had with ala before becoming its secretary the answers to these questions lead to better understanding of milam the association and their close relationship
CISI	chemical and engineering news chemical abstracts service along with the entire acs publications program is converting to a computer base this change in our basic method of handling information will provide powerful new tools for chemists and chemical engineers to meet their information needs our goal is a unified system that will produce both a full printed record of chemical and chemical engineering knowledge and a variety of timely special subject alerting services simultaneously providing a mechanized match and retrieval system that is sufficiently flexible to meet the varied needs of information users the output will be supplied in whatever form best suits the users needs   printed pages microfilm or computer searchable tapes tapes and search programs will be usable on the customers computer or cas will provide custom matches of its own computer files
CISI	worlds chemical literature continues to expand abstracts of scientific papers from journals and other serial publications which now make up about 85 of the abstracts in ca increased at an average annual rate of 8 4 between 1961 and 1970 compared with 8 2 in the previous decade the number of such abstracts published annually now is doubling every 9 years the number of patent abstracts increased at an average rate of 5 per year in the 1960s compared with 11 7 in the 1950s however the total number of patents covered by ca either by actual abstracts or through the ca patent concordance grew at an average rate of 10 9 from 1961 through 1970
CISI	chemical information systems the purpose of a chemical information system must not be restricted to the storage and retrieval of facts it is equally important that the system shall provide methods which enable a scientist to assemble and to correlate the facts chemical information systems are required primarily as a service to research chemists to enable them to keep up to date with current developments in their fields of interest and the establishment of information services has relieved the chemist of many of his problems of literature searching and information storage and organization
CISI	what do chemists read most british universities are spending at least 3000 pounds per year on chemical journals alone and this does not include any administration or binding costs which may be as much again are the universities getting their moneys worth out of these journals this survey of one particular chemistry department suggests that they are not
CISI	the civic culture we are concerned in this book with a number of classic themes of political science with what the greeks called civic virtue and its consequences for the effectiveness and stability of the democratic polity and with the kind of community life social organization and upbringing of children that fosters civic virtue in using survey research to study these classic themes we are also following the traditional practice of relying on the most precise methods available to us for the investigation of these problems perhaps tocqueville and bryce were they living today would have relied somewhat on the cross section survey in their comparative studies of democratic attitudes
CISI	classification for a general index language the role of classification schemes in libraries and information services has probably caused more argument than any other professional activity this would be surprising if classification were no more than a fairly convenient way of arranging books on shelves some librarians think it is and support their view by heaping scorn on the heads of those who like the classification research group actually spend years of their time in theoretical discussions that seem to result in more and more abstruse and difficult complications to what ought to be a straightforward exercise yet today we can see clearly two relatively new spectacles on the library scene on the one hand some librarians are criticizing the decimal classification especially as used in the british national bibliography for being too detailed and unwieldy on the other hand some librarians and still more information officers are busy revising the universal decimal classification in order to make it more detailed in the next field as it were computerized indexing and retrieval systems are pounding away at the ever growing masses of literature producing results that impress computer specialists but not information users who are so deafened by the noise that they cannot hear what is new
CISI	classification and indexing in science the first problem that of learning of a publications existence is tackled by a multiplicity of abstracting and indexing journals and other bibliographies and at local levels by library catalogues and unnecessary overlapping among these services while ensuring adequately comprehensive coverage are very great but even if these were overcome problems of the internal arrangement of these bibliographical aids would still remain it is not enough for them collectively to record every scientific publication the user must be able to find every such record starting only with a subject on which he wants information
CISI	classification and indexing in science the preface to the first edition of this book   which is reproduced following this   shows that in 1958 the classification ideas in it were felt to be controversial needing to be championed a few years before the classification research group had issued a memorandum proclaiming the need for a faceted classification as the basis of all methods of information retrieval  as part author of this memorandum i must now judge the claim to have been too bold even brash but it has been vindicated to an extent for both in theory and practice the value of facet analysis in the organization of subject vocabularies for indexing and search has been widely accepted   whether these vocabularies are classified or alphabetical and whether used in pre  or post coordinate fashion
CISI	classification practice in britain report on a survey of classification opinion and practice in great britain with particular reference to the dewey decimal classification the objectives of the sub committee in starting their enquiries were basically three fold 1 to gather a reasonable collection of statistics relating to the general practice of classification in this country 2 to gather information on th actual use of the dewey decimal classification in this country 3 to provide a basis for the recommendations which are provided periodically for the dewey editorial policy committee from the library association library research committees sub committee on dewey decimal classification revision to this end a questionnaire was sent out to over 1100 libraries of all types throughout the country and after six months reminders sent to librarians to ensure they had received them and that none had been overlooked the result of this was very pleasing 716 were returned the vast majority completed correctly the actual figures of type and size of library are given in the body of the report but no type of library is completely omitted and a significant proportion of the larger libraries returned the questionnaire
CISI	classification scheme for law books an examination made over a period of years of the principles of classifying law books for use in libraries and of their treatment in many general and specialized classification schemes convinced me that no scheme existed which was generally suitable for libraries in english  speaking countries outside the united states law collections in academic libraries in the united kingdom and the commonwealth were in a particularly difficult position they had the choice of adopting one of the good american schemes which generally make inadequate provision for the needs of overseas commonwealth libraries or of adopting one of the english schemes each of which is virtually tailored to a particular library and several of which are even less well suited to overseas libraries or of devising new schemes for themselves there seemed to be an urgent need for a practical law classification scheme capable of being used in a variety of libraries large and small general and special academic and professional in these countries
CISI	classification and subject index for a library the plan of the following classification and index was developed early in 1873 it was the result of several months study of library economy as found in some hundreds of books and pamphlets and in over fifty personal visits to various american libraries in this study the author became convinced that the usefulness of these libraries might be greatly increased without additional expenditure three years practical use of the system here explained leads him to believe that it will accomplish this result for with its aid the catalogues shelf lists indexes and cross references essential to this increased usefulness can be made more economically than by any other method which he has been able to find the system was devised for cataloguing and indexing purposes but it was found on trial to be equally valuable for numbering and arranging books and pamphlets on the shelves
CISI	classification catalogue code the author the dictionary and the classified catalogues represent three successive stages in the order of evolution of the internal form of the library catalogue the classified form being the latest to evolve the literature relating to it is comparatively scanty it is strikingly so in the form of a systematic code of rules for cataloguing while the number of codes for the author catalogue is fairly large and the number for the dictionary catalogue is also respectable there appear to be few systematic and complete codes published in book form for the classified catalogue hence this little venture which is based on twenty five years of experimentation and on the valuable reciprocal influence gained by its being taught to students of library science during the last twenty years while the call numbers occurring in the examples given are constructed by the colon classification the rules of this code are not necessarily dependent on that scheme for their applicability they are all of general application irrespective of the scheme of classification in use
CISI	cleaning and processing bindings and related materials the destructive effects of air pollution in the modern city upon the health of its people its trees and its gardens even its buildings and statues are well known and are being increasingly fought against but the public generally and even many librarians and book collectors who should know better are apparently unaware of the rapid deterioration of the worlds libraries under these conditions in libraries museums and private homes preventive care is regularly given to pictures and sculpture fine furniture silver and brass but the gradually deteriorating volumes on the shelves are given no more attention than an occasional dusting which abrades the books more than it protects them i would judge that more than 90 percent of the books and documents that come to my bindery for repair or restoration are in a condition that could have been avoided by regular and appropriate preventive care unfortunately even when the custodians of books become aware of the problem they my be handicapped by the relative unavailability of expert advice on what procedures to follow in conserving their libraries the present essay is intended to meet this need
CISI	code of cataloging rules the following rules represent a system designed to produce an instrument essential to the operations and services of a library    its catalog to understand the rules and to apply them properly it is necessary to comprehend the objectives which the catalog is to serve the method by which these objectives are to be achieved the basic aspects of the problem of cataloging and the general principles which underlie the rules objectives the objectives which the catalog is to serve are two first to facilitate the location of a particular publication i e of a particular edition of a work which is in the library second to relate and display together the editions which a library has of a given work and the works which it has of a given author
CISI	quantitative criteria for adequacy of academic library collection the authors challenge accepted doctrine which asserts that the adequacy of an academic library cannot be measured by the number of books which it contains out of their feeling that the standards for college libraries and the standards for junior college libraries are inadequate for estimating the size in volumes required for minimum adequacy by libraries of institutions of higher education of widely differing characteristics they developed new formulas for this purpose these formulas attempt to identify the principal factors affecting academic needs for books and to ascribe suitable to each factor the authors then illustrate the application of the formulas to specific institutions and conclude that while the results are useful further research in needed they end by suggesting specific topics for such research
CISI	system analysis in university libraries a comprehensive enginnering approach to the analysis and functional design of library systems is described in terms of fundamental space time relationship which characterize university libraries long run trends in aquisitions and circulation are related to the relative obsolescence of stored materials and the uncertainty of short run demand pattern is related to the need for excess service capability the spatial dispertion of library resources among specialized information centers and central depositories is considered with respect to availability retrieval duplication and efficient storage
CISI	subject specialists in a university library in an attempt to supply in other disciplines the bibliographical expertise traditionally furnished by university library systems to departments with departmental libraries indiana university has over the past three years established ten subject specialist positions in the social sciences humanities and area studies programs these librarians select materials render reference service to faculty members and graduate students give instruction in library use and serve generally as the main channel of communication between the library and the academic departments to which they are allied
CISI	sampling and short period usage in the purdue library several possible methods of sampling of social science monograph titles in the general library of purdue university were considered and a good method was used to obtain estimates of their usage in the library and at home during the period july 1   august 4 1964 the term relative usage was defined and used to study the effect of 1 language 2 country of publication 3 year of publication and 4 year of accession of a monograph title an attempt was made to fit a regression model for titles in english by quantifying the last three independent variables with relative usage as the dependent variable functions based on the above variables have been developed to identify monograph titles for storage a questionnaire was employed to stady the usage of library facilities and to gather opinions of library patrons purpose of visiting the library reason for checkout of library material reason for preferring library or home for the use of library material etc were analyzed on the basis of the replies received
CISI	conflict in libraries intergroup conflict in libraries is explored including conflict between departments between professionals and bureaucracy and between older and newer staff members other special interests such as informal power holders and the subprofessional are identified this analysis shows that existing organizational relationships in libraries let means become ends strong forces toward conformity hamper desirable growth and change a restructuring of libraries is proposed along the lines of professional rather than semiprofessional organizations principal changes to be made are in existing processing service relationships and administrative professional relationships
CISI	determining and allocating book funds for current domestic buying a device is outlined to help formulate the annual book budget request courses described in the college catalog are matched with the books listed in the american book publishing record bpr cumulative 1965 courses treated as if monographes are designed dewey classification numbers and arranged in decimal sequence by groups books in bpr falling into the groups are tallied the dc groups are then rearranged by departments and the number and cost of books in each are totaled results are sound estimates of each departments probable current domestic book needs for that year and may be applied to the subsequent year as an estimate of what will probably be needed they may be used as factors in an allocation formula
CISI	professionalism reconsidered the question of librarianship as a profession is considered here in terms of the three key relationships of a professional client organizational and professional professional practice in this field is thus cast against accepted norms and standards of professional behavior this critical assessment suggests that librarianship falls far short of the professional model major shifts in the nature of the services performed by librarians and in their bureaucratic relationships will be required if librarianship is to advance the contributions of the professional associations and of library schools to the advancement of the process of professionalization is also analyzed progress in the field is viewed to be inextricably tied to the success or failure which librarianship achieves in its quest for true professional attainment
CISI	the bottomless pit or the academic library as viewed from the administration building library administrators could adjudge their likely fortunes in the academic tug of war for funds if they understood more clearly the attitudes of institutional administrators toward libraries some view the library as a bottomless pit all recognize that the library is unlikely to generate much political pressure for its own aggrandizement many young institutional administrators are coming to apply more sophisticated measures to their funding formulas than have been utilized in the past librarians therefore would be well advised to become more proficient in modern management techniques and program budgeting concepts
CISI	question negotiation and information seeking in libraries seekers of information in libraries either go through a librarian intermediary or they help themselves when they go through librarians they must develop their questions through four levels of need referred to here as the visceral conscious formalized and compromised needs in this pre search interview with an information seeker the reference librarian attempts to help him arrive at an understanding od his compromised need by determining 1 the subject of his interest 2 his motivation 3 his personal characteristics 4 the relationship of the inquiry to file organization and 5 anticipated answers the author contends that research is needed into the techniques of conducting this negotiation between the user and the reference librarian
CISI	measuring classified circulation according to curriculum circulation statistics can be precise reflections of library use according to the curriculum the statistics can help the librarian decide how to allocate the budget to departments traditional counts by department personnel or by broad dewey or lc classes are imprecise an analogy between curriculum and circulation can be constructed by classifying courses in the college catalog by dc or lc rearranging the numbers thus generated by department and then counting circulation within those groups the analogy is thus a quantitative measure and a precise reflection of library use according to curriculum
CISI	the title catalog a third dimension the accessibility of the card catalog seems to be inversely proportional to the complexity of its arrangement a catalog divided into author title and subject sequence simplifies the filing order of cards and facilitates the use of each catalog it is argued here that a three way division into author title and subject catalogs will further augment these advantages in this paper a separation of the title catalog at the university of wisconsin milwaukee library is described and evaluated
CISI	an allocation formula derived from a factor analysis of academic department the authors derive a book fund distribution formula from a factor analysis of twenty two variables which measure and quantify academic departments the analysis generates a 22 x 22 matrix of correlations a few of the significant correlations are discussed e g those between books published and books circulated high correlation and circulation by subject and circulation by person low correlation the factor analysis sorts out the complex relationships between the twenty two variables and reduces them to three main factors   two of which seem to describe materials used and users the third may describe needs the three factors are the chief elements in the formula each factor can be represented by any one or more of the variables in that factor
CISI	random sampling a tool for library research questions about the accuracy of library records the behavior or attitudes of patrons or the conditions of the books in the collection can often be answered by a random sampling study use of this time and money saving technique requires no special mathematical ability or statistical background the concept of accuracy is discussed and a table is provided to simplify the determination of an appropriate sample size a method of selecting a sample using random numbers is shown three examples illustrate the application of the technique to library problems
CISI	program budgeting and cost benefit analysis in library libraries in academic institutions have traditionally prepared annual budgets based either upon subjective judgments or upon oversimplified formulas two budgeting techniques recently introduced into universities from the defense establishment are program budgeting and benefit analysis properly applied they can be utilized to gain better decisions in problems facing academic library managers and improved allocation of library resources
CISI	user circulation satisfaction vs size of holdings at three academic libraries in an effort to determine certain facts concerning the relation of circulation satisfaction to collection size the author sampled the last circulation date of stack books and of circulated books in three considerably different kinds of academic libraries the experience of these three libraries proved to be surprisingly similar the author speculates concerning potential uses to which such data might be profitably applied
CISI	the economic goal of library automation a steadily increasing rate of productivity should be the economic goal of library automation such productivity will be achieved only by development of a new library technology thereby rise in library costs which are going up exponentially at a frightening rate will be brought into line with cost rises in the economy as a whole
CISI	classifying courses in the university catalog the authors contrast the university catalog and the card catalog and conclude that the university catalog is the best guide to the universitys current scholarly interest they urge that librarians study and classify courses therein such as books using the library of congress or dewey decimal schemes so that specific class number are grouped by academic department and become substantial spans the profile can be used as a selection tool as a correlating tool between curriculum circulation and publishing and as a device to aid weeding and shelving general and specific quidelines for classifying including a method for resolving apparent duplication of courses in different departments are presented time and unit figures are tabulated specific steps in classification and editing are described
CISI	academic status for college and university librarians   problems and prospects academic librarians will archive and deserve full academic status only after they cause changes in the bureaucratic structure of libraries and in library education and when they provide professional service on a scholarly level
CISI	automation stops here a case for man made book collections the following paper was read at the second international seminar on approval and gathering plans for large and medium size academic libraries kalamazoo michigan october 31 1969 we print it here because its dissenting viewpoint is a timely as it is provocative
CISI	modernizing the university library structure among the several kinds of change that appear to be in order in personnel management in university libraries some have been described others have not there has perhaps been a super abundance of attention devoted for example to the inadequate treatment of librarians within the university community as a whole but little discussion has thus far appeared in print concerning their treatment within the library itself this paper will attempt to define certain progressive changes that it is possible and probably desirable for the library to implement internally regardless of the universitys willingness to consider improving the librarians lot in the larger community
CISI	users reaction to microfiche a preliminary study recent emphasis placed on the use of microfiche by large government agencies has increased the pressure in libraries supporting government research to make greater use of microfiche negative and apathetic user attitudes expressed by researchers indicate that expanded efforts to overcome resistance if the great potential of microfiche is to be realized efforts in microphotography expended on technical achievement in the past should be directed toward understanding the user and his needs to discover why he avoids microforms and how to overcome his resistance to them
CISI	major decision points in labrary automation this article is based on a longer more detailed paper prepared for the 1970 midwinter meeting of the association of research libraries readers interested in the complete test with bibliography are referred to the minutes of the arl meeting the author discusses automation in the context of the management facilities and system requirements for large research libraries
CISI	an approach to performance budgeting at the florida atlantic university library the article summarizes the problems encountered at the fau library in the 1967 and the librarys subsequent reorganization a detailed cost study is analyzed and the clapp jordan and university of washington formulae for budgeting are described as well as a modified formula the resulting program performance budgeting system is now in use by the state university of florida
CISI	the great gas bubble prickt or computers revealed   by a gentleman of quality in which are exposed the delicious delusions of those will o the wisps the echoes is computerization of phrenology haruspication and other discredited ancient sciences and the moral and mental decline of our profession
CISI	correlation the subjects of books taken out of and books used within an open stack library the traditional over the counter circulation count is not always considered a reliable indicator of total library use to test this assumption the author hypothesized that no correlation exists between the subjects of books taken out of the library and those used within the library counts were made of books left on tables chairs desks and other surfaces and correlated to books charged out two studies were made in the first books were counted within finely delineated lc and dewey class spans relating to academic departments in the second books were counted within the broad lc first and second letters and the dewey tens in the first case the overall correlation was 86 in the second with less data 84 the author concludes that out of library circulation totals can be reliable indicators of in library use for predicting in library use and thus total use two methods are cited simple ratio of out to in and the regression equation
CISI	a generalized methodology for library systems analysis this article is directed toward the service in systems work its purpose is to generalize at a very elementary level a methodology or approach which can be used in conducting a systems study systems work is discussed here as a point of view a logical coherent from the top down preface to decision making and resource allocation which utilizes a very powerful body of sophisticated techniques the approach and techniques reviewed in this paper however will be those on the most elementary level no attempt will be made to discuss the techniques of queueing inventory management linear programming simulation marginal analysis game theory statistical inference or any of the other highly sophisticated techniques available to the operations research systems analysis or sa analyst when the systems approach is clearly understood and properly used it becomes a potent weapon in the arsenal of the administrator rather than a review of the tools themselves a delineation of this systems methodology and point of view will be considered in this article the methodology discussed here embraces a number of standard techniques used by the systems engineer time and motion analyst operations researcher and occasionally even the librarian
CISI	cost accounting and analysis for university libraries the approach to library planning studies in this paper is the use of accounting models to measure library costs and implement program budgets a cost flow model for a university library is developed and tested with historical data from the general library at the university of california berkeley various comparisons of an exploratory nature are made of the unit costs and total costs for different parts of the berkeley system
CISI	change in academic libraries never noted for their willingness to accept innovative suggestions and implement change from outside sources academic libraries have remained institutions in which changes in service policies and programs originated from internal sources only in order to shift to an orientation that seeks to develop new and expanding service programs the establishment to research groups could do much to improve both the services offered by a library and its role in the academic community while certain constraints always limit modification or the initiation of services a properly constituted research group could do much to generate a climate for change provide feedback to the library and successfully continue to develop new and more effective library and information services
CISI	key factors of circulation system analysis and design librarians must frequently judge circulation systems on the basis of widely disparate descriptions that make comparisons difficult a way is needed to place various systems into a common perspective framework so that their similarities and differences can be readily understood this paper explains basic and largely familiar concepts and components that are common to manual machine aided and computer based systems and documents their significance as key factors in the analysis and design of academic library circulation systems cost factors are not discussed
CISI	an approach to the measurement of use and cost of a large academic research library system a report of a study done at columbia university libraries a description of the methodology used in collecting performance data in a large academic research library is given twelve types of surveys used to measure and evaluate users services and materials were developed and conducted during the period 1968 69 at columbia university libraries and later evaluated sample results are included costs of providing research services were found to be 64 percent versus 36 percent for instructional services
CISI	participative management in relation to library effectiveness this paper reviews a recent study on the influence of participative management on library performance because most of the recent theoretical and empirical research being done in this area is ignored and an invalid measure of participation in decision making is used the study provides no basis for the generalization that in increase in the library staffs participation in decision making will increase the librarys effectiveness
CISI	the evaluation of campus library document delivery service a campus delivery service is one way to increase accessibility of library materials this report provides an overview of such a service evaluates its performance notes the economic implications and concludes that the service can solve some of the problems of decentralized collections
CISI	the changing role of directors of university libraries the role of the university library director has changed markedly in the last decade the position of library director has become a difficult role to serve directors has been subjected to pressures from different quarters five sources are identified by the authors including pressures from the presidents office library stuff faculty and students these difficulties coupled with a declining ability to meet user needs the lack of cohesive library planning and an institutional inability to accommodate change have all contributed to the declining status of the library director recommendations as to ways to ameliorate the problem are offered among the suggestions included are better planning improved budgeting techniques and the introduction of new organizational patterns
CISI	an approach to developing computer catalogs a method of developing computer catalogs is proposed which does not require unit card conversion but rather the accumulation of data from operating programs it is proposed that the bibliographic and finding functions of the catalog be separated with the latter being the first automated such automation is seen as being advantageous on a cost basis
CISI	faculty awareness and attitudes toward academic library reference services a measure of communication a survey of the faculties at six colleges was undertaken to measure the degree to which the libraries of those institutions were communicating with the faculty concerning the availability of various references services the results demonstrated that the average faculty member was aware of barely half the services actually available variables of academic rank length of teaching and amount of library and reference use were some of the factors shown to affect faculty awareness of library service
CISI	staff participation in management in large university libraries a clr fellowship in 1971 72 enabled the author to examine staff participation in the management of large academic libraries the report considers the climate of participation preparation given the staff areas of decision making the role of the professional staff association and the reaction of staff to such participation
CISI	applying management by objectives to the university library many methods of library management are no longer sufficient to meet the more sophisticated demands of today a promising management technique for librarians is managements by objectives which helps to establish library goals measure performance objectively and to identify factors affecting an operations final results
CISI	reference bibliographers in the college library one approach to making college library more relevant dynamic and intelligible is to employ specialists with broad subject competence throughly familiar with the terminology bibliographic tools and major writings of several related disciplines these subject specialists or reference  bibliographers provide reference and institutional services and serve as coordinators between academic departments and the library a significant increase in the quality of library service is attained with reference  bibliographers both building and interpreting the collection the reference  bibliographer concept is examined from several perspectives historical antecedents relationship to the academic setting and the authors experience with a staff of subject specialists at a predominantly undergraduate college library during 1969 1972
CISI	the management review and analysis program an assisted self study to secure constructive change in the management of research libraries the management review and analysis program mrap designed tested and operated by the association of research libraries office of university library management studies oms is an assisted self study strategy intended for use by large academic and research libraries the program assists libraries in reviewing and analyzing their current management policies and practices and provides guidelines for the application of contemporary principles of management for the improvement of library programs
CISI	allocating the book budget a model inflation is currently affected library book budgets particularly with respect to the acquisition of serials a model is proposed which would balance the purchase of serials against the purchase of monographs by individual funding units within the academic library special consideration is given to inflation as a cost factor affected by both the form of publication and the subject matter applying the model to a specific example demonstrates its use in providing control over collection development and allowing for equitable distribution of book funds among funding units
CISI	from economic to political analysis of library decision making in general the more critical the decision the less useful a cost benefit analysis is to library decision makers political analysis is required and eastons conceptual framework is presented to suggest the utility of political analysis a list of normative issues is derived from raising descriptive questions about the politics of university libraries
CISI	providing access to externally available bibliographic data bases in an academic library the ready availability of externally processed bibliographic data based has made it possible for an academic library to provide computerized searches on a large number of data bases with a very small initial investment and utilizing its own personnel the experience of the university of pennsylvania libraries has confirmed that such an approach is indeed feasible this article discusses the approach questions and problems encountered and the factors considered in their resolution also discussed are the role of the data services librarian the cost incurred and some observations as to the philosophy of the approach with particular attention to the integration of the service into the reference department
CISI	the coming crisis of western sociology the criticism and transformation of society can be divorced only at our peril from the criticism and transformation of theories about society yet the gap between theory and practice so common in the history of american radical movements is in some quarters growing wider some of the most militant of american radicals in the new left or in the movement for black liberation have at least temporarily avoided any serious concern with social theory this neglect of theory doubtless has various origins in some part it is due to the fact that these social movements are still new and their political activism consumes their necessarily limited energies and resources the new radicalisms will in short need time to produce their new theories although the neglect of theory is scarcely peculiar to americans it is in part also due to the fact that american radicals are often more american than they know and may prefer the tangible outcomes of pragmatic politics to the intangible outputs of theory again part of their neglect of theoretical problems is probably due to the close links that some young radicals have with the hippie contingent of their generation whose more expressive and aesthetic styles of rejecting american culture dispose them to avoid what they take to be the sterile hassles of intellectual confrontation there is also a vocal minority who as has been said feel personally excluded when they hear an appeal to reason
CISI	the smart automatic document retrieval system   an illustration a fully automatic document retrieval system operating on the ibm 7094 is described the system is characterized by the fact that several hundred different methods are available to analyze documents and search requests this feature is used in the retrieval process by leaving the exact sequence of operations initially unspecified and adapting the search strategy to the needs of individual users the system is used not only to simulate an actual operating environment but also to test the effectiveness of the various available processing methods results obtained so far seem to indicate that some combination of analysis procedures can in general be relied upon to retrieve the wanted information a typical search request is used as an example in the present report to illustrate systems operations and evaluation procedures
CISI	a relational model of data for large shared banks future users of large data banks must be protected from having to know how the data is organized in the machine the internal representation a prompting service which supplies such information is not a satisfactory solution activities of users at terminals and most application programs should remain unaffected when the internal representation of data is changed and even when some aspects of the external representation are changed changes in data representation will often be nedded as a result of changes in query update and report traffic and natural growth in the types of stored information existing noninferential formated data systems provide users with tree  structured files or slightly more general network models of the data in section 1 inadequacies of these models are discussed a model based on n ary relations a normal form for data base relations and the concept of a universal data sublanguage are introduced in section 2 certain operations other than logical inference are discussed and applied to the problems of redundancy and consistency in the users model
CISI	communication among scientists and engineers since 1966 the johns hopkins university center for research in scientific communication has been conducting studies of the information flow process   the production dissemination and assimilation of information   associated with nine scientific and engineering disciplines this process in most disciplines appears from the dissemination point of view to consume about five years   from the time a scientist begins his research until reports of his findings are cited in a review to date we have conducted over sixty studies of this process and since one of the main goals of our program is to make genuine comparisons of the scientific communication associated with the disciplines being studied we have standardized the procedures instruments and analyses in those of the major studies which were conducted for all disciplines we will present findings from the major studies conducted to date in order 1 to indicate the types of data we have collected on approximately 30 000 scientists and engineers during the past three years 2 to indicate some of the goals of our program and 3 to suggest a preliminary picture of the communication structure of science as our program has led us to perceive it
CISI	communication of innovations a cross cultural approach in the present edition we have to a far greater extent integrated diffusion research with the scientific study of human communication diffusion researchers have long been aware that they were investigating a special type of communication behavior in this book we stress communication concepts and frameworks in our analysis of the diffusion process we feel this provides an advantage of conceptual clarity as well as ease of wide expression our adoption of the communication viewpoint is reflected in the addition of several chapters the complete reorganization of all chapters and the frequent inclusion of new concepts
CISI	communication among scientists and engineers in the course of collecting data on nine scientific and technological disciplines it has become obvious to us that in their communication activities some disciplines behave quite differently from others recently we have reanalyzed our data for the physical the engineering and the social sciences we do not have time to discuss differences among all three groups so we have decided to compare only the physical and social sciences we have included data pertaining to the engineering sciences on the graphs however so you can get some idea of how they differ from the other two groups before discussing these differences we should like to emphasize that there are similarities that there are of major importance and that they in fact make genuine comparisons among the groups feasible we will discuss differences between the physical and the social sciences in terms of three major communication characteristics associated with science
CISI	citation measures of hard science soft science technology and nonscience perhaps the fundamental problem of those that work in the scientific information industry is that it is not just that special part of an information industry that happens to deal with material having a scientific content technical librarianship involves much more than librarianship applied to books with an esoteric vocabulary and much mathematics my reason for choosing this problem as a contribution for such a strategic conference is that i know well as an historian of science that the greatest and most useful advances in our technologies have not come from the applied research of trained people trying to make themselves useful to society but rather from basic research aimed at furthering understanding and curiousity and powered by the latest instrumentation that the useful people have devised i suspect that all the new indexing tools and computer handlings will be more useful to basic research in understanding scientists than they will to solving practical problems for which they are designed it seems clear however that it is only such new understanding that can bring success whatever solutions ultimately emerge
CISI	automatic abstracting and indexing   survey and recommendations in preparation for the widespread use of automatic scanner which will read documents and transmit their contents in automatic analysis the relative  frequency approach to measuring the significance of words word groups and sentences the relative frequency approach is discussed in detail as is its application to problems of automatic indexing and automatic abstracting included in the report is a summary of automatic analysis studies published as of the date of writing conclusions are drawn that point toward more sophisticated mathematical and linguistic techniques for the solution of problems of automatic analysis
CISI	scatter storage techniques scatter storage techniques as a method for implementing the symbol tables of assemblers and compilers are reviewed and a number of ways of using them more effectively are presented many of most useful variants of the techniques are documented
CISI	natural language question   answering system 1969 recent experiments in programming natural language question answering system are reviewed to summarize the methods that have been developed for syntactic semantic and logical analysis of english strings it is concluded that at least minimally effective techniques have been devised for answering questions from natural language subsets in small scale experimental systems and that a useful paradigm has evolved to guide research efforts in the field current approaches to semantic analysis and logical inference are seen to be effective beginnings but of questionable generality with respect either to subtle aspects of meaning or to applications over large subset of english generalizing from current small scale experiments to language processing systems based on dictionaries with thousands of entries   with correspondingly large grammars and semantic systems   may entail a new order of complexity and require the invention and development of entirely different approaches to semantic analysis and question answering
CISI	a formal system for information retrieval from files a generalized file structure is provided by which the concepts of keyword index record file directory decoding and record retrieval are defined and from which some of the frequently used file structures such is inverted files index sequential files and multilists files are derived two algorithms which retrieve records from the generalized file structure are presented
CISI	inefficiency of the use of boolean functions for information retrieval systems in this note we attempt to point out why boolean functions are in general not applicable in information retrieval systems first we wish to stress that a system which supposedly is to serve a certain purpose has to try to optimize some overall performance rather than certain detailed parts of it this situation is of course well known saying that a system should cater to an optimal performance implies that the reward varies with different circumstances that is there may always be some customers who will not agree that the systems output is satisfactory however these should be relatively few in the case of an information retrieval system let us consider one whose function is to furnish a reference list as a reaction to a question so if we have a set of documents s and a set of questions q the system has to assign to each question q an answer a q which is a subset of s naturally this answer cannot be chosen arbitrarily it should reflect a relation between the question and the resulting reference list usually one says that the documents in the list are relevant to the question more precisely stated we assume that the enquirer expects a certain reference list namely the one he would have procured had he himself probed the documents in the set
CISI	the teachable language comprehender a simulation program and theory of language the teachable language comprehender tlc is a program designed to be capable of being taught to comprehend english text when text which the program has not seen before is input to it it comprehends that text by correctly relating each explicit or implicit assertion of the new text to a large memory this memory is a semantic network representing factual assertions about the world the program also creates copies of the parts of its memory which have been found to relate to the new text adapting and combining these copies to represent the meaning of the new text by this means the meaning of all text the program successfully comprehends is encoded into the same format as that of the memory in this form it can be added into the memory both factual assertions for the memory and the capabilities for correctly relating text to the memorys prior content are to be taught to the program as they are needed tlc presently contains a relatively small number of examples of such assertions and capabilities but within the system notations for expressing either of these are provided thus the program now corresponds to a general process for comprehending language and it provides a methodology for adding the additional information this process requires to actually comprehend text of any particular kind the memory structure and comprehension process of tlc allow new factual assertions and capabilities for relating text to such stored assertions and capabilities for relating text to such stored assertions to generalize automatically that is once such an assertion or capability is put into the system it becomes available to help comprehend a great many other sentences in the future
CISI	an information theoretic approach to text searching in direct access systems using direct access computer files of bibliographic information an attempt is made to overcome one of the problems often associated with information retrieval namely the maintenance and use of large dictionaries the greater part of which is used only infrequently a novel method is presented which maps they hyperbolic frequency distribution of text characteristics onto a rectangular distribution this is more suited to implementation on storage devices this method treats text as a string of characters rather than words bounded by spaces and chooses subsets of strings such that their frequencies of occurrence are more even than those of word types the members of this subset are then used as index keys for retrieval the rectangular distribution of key frequencies results in a much simplified file organization and promises considerable cost advantages
CISI	the community college library this study deals with the learning resources programs of the public two year colleges in former years these institutions were commonly called junior colleges and the college departments or divisions that assembled organized and interpreted the learning resources mainly books were commonly called libraries in keeping with traditional terminology i could have chosen the junior college library as the title for the study however i decided to modify the title to make it correspond more closely to prevailing current terminology
CISI	comparative and international librarianship essays on themes and problems in this decade professionals in the field of librarianship and the information sciences will continue to be faced with most of the problems that have haunted libraries for generations problems that can be best summed up as the attempt to reduce the anonymity of information there will also be many new problems some of these are already becoming apparent while others are still unknown but librarians need not despair the past record is clear through the use of sophisticated electronic machines we have begun to master the bibliographical control and retrieval of information we have improved the communication between librarians and the consumers of information on a national and international basis and we have refined the many problems concerned with cataloging and classifying information in addition library education has been on the front line in trying to educate people to understand the complexities of organizing and disseminating information of all types
CISI	computational analysis of present day american english readers can expect to find many parts of this volume tantalizing the definiteness of the answers to certain questions irresistibly provokes more questions the happy feature is that the book provides information required to limit the effect to that of tantalizing rather than frustrating for there is given here a wholly adequate description of the nature of the corpus of present day edited american english on which this study is based the details of its constituents and the modes of its transfer to tape a replica of that tape is available at a small cost in money which is minuscule compared to the cost in time needed to produce a like corpus accordingly any reader who seriously wants answers to further questions can set about getting those answers
CISI	computer based library and information systems this book describes some of the various ways in which a computer could be used as part of a library system in doing so it aims to bridge the gap between librarian and computer specialist by introducing computers to those involved in library work especially students of librarianship and at the same time helping to make those interested in the computer applications field aware of the potential and problems of the library environment
CISI	computer filing of index bibliographic and catalog entries the need to establish a filing code for computer arrangement has become increasingly apparent as more and more book catalogs and indexes have been prepared mechanically many of the difficulties in manual filing as shown in the a l a rules for filing catalog cards become even more intricate to cope with when computers are used of course if cost is not an object the theoretical potentialities for computer programming are practically limitless however modifications in rules and procedures can make the alphabetic arranging or merging of index catalog or bibliographic entries by computer more readily possible and these modifications are made in this proposed code for computer filing of complex alphabetic entries
CISI	computer handling of chemical structure information far reaching changes in the patterns of communication in science are at present in motion which seem likely to have fundamental effects on scientistss use of and access to existing knowledge these changes derive from the increasing involvement of computer techniques in the publication dissemination and retrieval of scientific and technical information many of the implications of the changes are not yet clear information handling is rapidly changing from a labour intensive industry to a capital intensive one as soaring man power requirements reflect the increasing flow of information and increasing demands for timeliness accuracy and improved access but the changes to be effected also have major social implications the reasons for publication and use of information are complex reflecting the factors of a sociological nature which are still imperfectly understood the rate at which innovations in information  handling win acceptance from scientists is determined partly by their appreciation of the greater flexibility which the novel methods offer but also by the sensitivity on the part of the designers and operators of information systems to the needs and habits of users and to their perception of the usefulness of the newer methods
CISI	current approaches to classification and clump finding at the cambridge language research unit computer programs for automatic classification are a desideratum in many fields work on suitable procedures for handling large bodies of object property descriptions has been in progress at the cambridge language research unit for some years this paper describes the current series of general purpose programs which have been developed there in which classes or clamps of objects are obtained using a similarity matrix by a simple iterative scan of the universe of objects distributing them in such a way that an appropriate cohesion function is minimized this actual clump finding process is embedded in a overall package in which the information given by a classification is manipulated in a variety of ways the current applications of the programs especially for information retrieval are described
CISI	the identification of variable length equifrequent character strings in a natural language data base the words of natural language texts exhibit a poisson or zipfian rank  frequency relationship i e a small number of common words accounts for a large proportion of word occurrences while a large number of the words occur as singletons or only infrequently inverted file retrieval systems using free text data bases commonly identify words as the keys or index terms about which the file is inverted and through which access is provided they therefore involve large and growing dictionaries and many entail inefficient utilization of storage because of the distribution characteristics an alternative approach may be based on the analysis of text in terms of sets of variable length character strings the frequency distributions of which are much less disparate than those of words this could lead to substantial reductions in dictionary size and increased efficiency both in dictionary look up times and storage utilization
CISI	computer readable bibliographic data bases    a directory and data sourcebook this document computer readable bibliographic data bases    a directory and data sourcebook not only updates the 1973 publication which included information on 81 data bases but expands the coverage to 300 data bases and includes considerably more information about the data bases methodology used to obtain data involved 1 consulting published and unpublished sources 2 design of a 13 page questionnaire 3 mail survey and 4 telephone follow up and verification the sources consulted were 1 the survey of commercially available computer readable bibliographic data bases 2 m e williams personal data base files which include information from the open literature news releases and personal contacts 3 newsidic april 1975 issue number 16 the quarterly newsletter produced by eusidic which included a survey of computer readable bibliographic files 4 the world inventory of abstracting and indexing services  data elements definition list and 5 the asidic survey of information center services
CISI	computerized library catalogs their growth cost and utility this book is a slightly modified form of a report on computerized library catalogs prepared for the office of education of the united states department of health education and welfare contract oec 1 7  071182 5013 it consists of seven chapters the first poses the problems that have been studied introduces background material to facilitate an understanding of their significance and presents our conclusions and general recommendations the remaining chapters belong to one of two parts depending on whether their principle concern is the utility or the cost of computeerized library catalogs because the problem of utility is the more speculative of the two it has been placed in the second part
CISI	on line text editing a survey this paper is a survey of current methods of the on line creation and editing of computer programs and of ordinary manuscript text the characteristics of on line editing systems are examined and examples of various implementations are described in three categories program editors text editors and terminals with local editing facilities
CISI	the concept of main entry as represented in the anglo american cataloging rules the work published here is rather like those conclusive statements of renaissance science that located the soul not in the human frame but in the human spirit the author of this work may face the wrath of the medievalists among our fellow professional catalogers at the least the publication of this book should encourage a complete reappraisal of our cataloging methods because the difference between title unit entry and author equivalent unit entry a confabulation of main and unit entry arising from tradition rather than practicality can be clearly seen not only in the job classifications and job descriptions of cataloging departments but also in our philosophy of librarianship
CISI	concepts and subject headings librarians are known for their organizational work with recorded knowledge information storage and retrieval are two well known basic functions associated with this work a search of the literature of library science reveals that these functions have not been examined to any significant degree from the users point of view this is true in regard to library catalogs and library subject headings
CISI	conceptual basis of the classification of knowledge as far as philosophers are concerned the conference seems to be justified precisely because of the present state of the classification of knowledge for two thousand years the classification of knowledge has been a major philosophical problem lately it has evolved from a philosophical preoccupation into a specialized technique a species of the general techniques of classification far removed from philosophical preoccupations and equally ignored by philosophers at the present time there exist powerful technical models of classification and highly developed classifications of various branches of knowledge what is lacking is a satisfactory general classification of knowledge and an adequate clarification of the philosophical problems underlying such classification the need for clarification is important from the theoretical as well as practical point of view because the general systems of classification of knowledge depend on theories of knowledge it is therefore highly desirable that philosophers and specialists in classification get together and discuss problems of common interest
CISI	conceptual design of an automated national library system this work describes a conceptual design of an automated national library system the design is conceptual in that it is intended to show the feasibility of a system concept rather than provide a detailed engineering design the design concerns an automated national library system but does not attempt to automate all parts of the system it is primarily concerned with the functions of bibliographic searching acquisition circulation and cataloging if these functions can be economically automated the major problems associated with our information explosion will be solved
CISI	conservation library this volume provides an introduction to the various facets of conservation as well as bibliographical data of permanent value in addition to being a critical description of the literature on the historic and technical aspects of the care repair and restoration of books prints maps and manuscripts and other important records it is a manual of practical guidance for librarians archivists curators conservators restorationists and bookbinders
CISI	contemporary problems in technical library and information center management a state of the art the review papers included in this volume represent one of the valuable products of the american society for information science the original draft papers were sponsored by the tisa technical information support activities project of the army corps of engineers as indicated on the reverse title page the basic objective of this tisa project was to improve the efficiency and effectiveness of department of defense dod technical libraries information centers and information analysis centers the establishment of priorities for tisa sponsored research was undertaken by the graduate library school of the university of indiana
CISI	continuing library and information science education this report and its recommendations are in response to the commissions request for a nationwide program of continuing education for personnel in the library and information science field while it is offered as only the start of an on going process of developing a nationwide program its recommendations are the result of an intensive nine month project involving hundreds of persons in the library and information science fields many of these persons participated in mini charettes in a written survey or in personal interviews which addressed major issues such as certification organizational and individual incentives for continuing education educational methods and continuing education needs the contribution of these library personnel cannot be overstated their collective wisdom and perspective have led the project team to many of its major recommendations however as would be expected when such a large number of people are involved there were differences of opinion even as there are many differences of opinion reflected in the literature of continuing education emanating from the various professions in the present study most of these differences related to the input into and control over the policies of the national structure three alternative models which have been considered are outlined in appendix d alternatives to several specific features of the recommended model are presented at the end of chapter 4 throughout the text when issues are presented on which there is uncertainty because of the intensity of opinions expressed these areas are identified
CISI	cooperation between types of libraries this bibliography uses the traditional typology of libraries as its starting point   public school academic research and special libraries this classification is most commonly used and provides a sufficiently clear distinction for the purposes of this work public libraries are those which are free to all residents of the librarys district and supported primarily from general public funds or taxes levied for library purposes local public libraries systems of public libraries and state library agencies are included in this category school libraries are those maintained by the governing boards of schools whether they be public private or parochial school libraries at the elementary junior high school and senior high school level are included academic research libraries include the libraries of institutions of higher education both public and private as well as libraries which while they might be defined as either public or special are widely known for their research resources junior college libraries college libraries university libraries and technical school libraries are included as academic libraries the library of congress the newberry library and linda hall library are examples of nonacademic research libraries special libraries are those directed toward making information available to people within a particular organization with fairly well defined information needs business and industrial libraries and the libraries of nonprofit organizations are common examples while distinctions between research and special libraries are not always easily made it is felt that in the case of this bibliography no serious problems are created
CISI	copying methods manual the current need for a manual of copying methods dealing with the processes methods techniques and types of equipment which can be used for reproducing documents of a great many different kinds arises from two factors 1 the great importance of document reproduction processes in the acquisition preservation dissemination and communication of information vital to the conduct of research work in all fields of human endeavor and on an international scale 2 the complexity of the field of document reproduction today which has resulted from the enormous technical advances made in the past fifteen years the need for the coining of the new class word   reprography an unfortunate graft of a latin fragment on a greek root   is in itself indicative of the great changes that have come about processes and methods which formerly were discrete and distinctive have now become intricately interrelated new processes and combinations of processes with different and astonishing capabilities continue to appear this revolution in the document copying field has been powerfully augmented by intensive competition on the part of manufacturers for a share of the vast and lucrative office records copying field the results however have led to highly important applications in the reproduction of research materials as well
CISI	corporate headings their use in library cataloguing and national bibliographics a comparative and critical study this study is an attempt to submit to a critical analysis the main problems related to corporate headings the difficulties raised by them and the solutions which now prevail in various countries in order to make the differences existing between the various solutions and the unsatisfactory character revealed by many of them more evident a great number of examples in a variety of languages extracted from cataloguing codes national bibliographies printed lists of corporate headings have been added these examples are also intended to draw attention to differences existing with regard to various technical details such as punctuation capitalization transliteration etc in addition many of these examples will clearly prove that certain solutions which may be considered to be suitable for one country or one language would not satisfy the requirements of another country or another language in the study examination and analysis of codes has been complemented by references to professional literature on the subject available to the author and by an analysis of opinions expressed there special attention has been paid to comparisons of cataloguing practices and citation usages and to investigations of the users approach to corporate headings it is well understood and appreciated that for the catalogue user the identification of and search for corporate headings present more problems than any other type of heading unfortunately however professional literature has as yet paid insufficient attention to these problems
CISI	a criticism and the growth of knowledge on almost all the occasions when we turn explicitly to the same problems sir karls view of science and my own are very nearly identical we are both concerned with the dynamic process by which scientific knowledge is acquired rather than with the logical structure of the products of scientific research given that concern both of us emphasize as legitimate data the facts and also the spirit of actual scientific life and both of us turn often to history to find them from this pool of shared data we draw many of the same conclusions both of us reject the view that science progresses by accretion both emphasize instead the revolutionary process by which an older theory is rejected and replaced by an incompatible new one and both deeply underscore the role played in this process by the older theorys occasional failure to meet challenges posed by logic experiment or observation finally sir karl and i are united in opposition to a number of classical positivisms most characteristic theses we both emphasize for example the intimate and inevitable entanglement of scientific observation with scientific theory we are correspondingly sceptical of efforts to produce any neutral observation language and we both insist that scientists may properly aim to invent theories that explain observed phenomena and that do so in terms of real objects whatever the latter phrase may mean
CISI	current problems in reference service current problems in reference service is a collection of thirty five new problem case studies intended for instructional use in both formal and informal teaching learning situations in the field of librarianship
CISI	data bases computers and the social sciences this book was written with several diverse audiences in mind 1 social and behavioral scientists and their students 2 librarians and library science students who are favorable about employing computers and computer usable information in their work and classes and 3 archivists and their employees who desire to have more than a current overview of the problems and their tentative solutions because of the diversity of material it is not expected that all readers will use the book in the same way rather it is assumed that readers will supplement a subset of the book with bibliographical materials from the reference sections
CISI	data study information whose handling is the topic of this book is generated by change and whatever is our unit of change is our unit of information in a situation in which only three possible moves can be made only three fundamental units of information can be found no matter how complex a structure we may build upon them our topic is therefore a special sort of change the change brought about in acquiring or keeping or transmitting elements of knowledge
CISI	cas computer based information services this paper describes the key points that characterize cas approach to large scale scientific technical information systems that must handle over 100 000 documents per year the first of these points is the single analysis multiple use concept intellectual ability is a rare commodity and essential to an information service therefore it makes sense to conserve that commodity and not use manpower to perform repetitive jobs or to waste effort analyzing information
CISI	a regional network   ohio college library center the ohio college library center is developing a computerized user oriented library system that will improve efficiency of library use and operations that will increase availability of library resources within a region and that will facilitate evolution of new and easier accesses to information in libraries the center does not conceive of its task as being merely the mechanization of library procedures of the past for the immediate future the principal academic objective of the center is to increase the availability of library resources for use in educational and research programs in colleges and universities throughout ohio a more distant objective is to enable libraries to participate actively in the programs of instruction and research in their institutions the passive service functions that libraries have developed during the past century are proving inadequate to meet the present demands made of libraries and will be increasingly inadequate in the future the per student costs of libraries are rising somewhat more than twice as rapidly as unit cost rises in the general economy therefore the principal economic goal of the ohio college library center is to decelerate the rate of rise of per student costs so that the rate of increase will approximate that of the economy as a whole
CISI	decision analysis introductory lectures on choices under uncertainty these lectures do not present a descriptive theory of actual behavior neither do they present a positive theory of behavior for a superintelligent fictitious being nowhere in our analysis shall we refer to the behavior of an idealized rational and economic man a man who always acts in a perfectly consistent manner as if somehow there were embedded in his nature a coherent set of evaluation patterns that cover any and all eventualities rather the approach we take prescribes how an individual who is faced with a problem of choice under uncertainty should go about choosing a course of action that is consistent with his personal basic judgements and preferences he must consciously police the consistency of his subjective inputs and calculate their implications for action such an approach is designed to help us reason and act a bit more systematically   when we choose to do so
CISI	the design of inquiring systems design is used throughout in its most generic sense to include planning operations research engineering design architectural design programming budgeting and all the other activities in which we consciously attempt to change ourselves and our environment to improve the quality of our lives so the book could be read as a philosophy of organization theory or of architectural or engineering design or of operations research or of planning the word inquiry suggests that the audience includes persons interested in the philosophy of science this is true so long as the interest is a very broad one concerned with the meaning of science with respect to other social institutions health education morality and so on inquiry is by no means restricted to the disciplines of science i could have called the book the design of systems but this would not adequately reflect my style which is to proceed from the more specific problem of inquiry to the whole system
CISI	deterioration and preservation of library materials the deterioration of library materials constant since libraries began has accelerated to alarming proportions in 1969 researchers have predicted that all paper based records of this century as well as those of earlier years face imminent ruin without new and effective efforts for their preservation most will not be usable in their present form in the next century the danger of destruction threatens not only research library collections but also the world of knowledge and scholarship that they support for not only paper is involved similar dangers of destruction confront other cellulosic products such as film which may substitute for paper as the material base of records and not only research libraries are involved the surprisingly rapid deterioration of printed materials even those that have been produced with some eye to permanence creates problems and expenses for other libraries as well
CISI	developing multi media libraries this book presents the concept of the modern library as a comprehensive resource center the philosophy and objectives of the center are clarified and desirable practices in the selection and acquisition of nonbook or audiovisual materials   interchangeably defined as those materials that communicate primarily through aural and visual stimuli   are recommended along with information pertinent to facilitating these tasks their organization in general in discussed with emphasis on the necessity for basic decisions and policies cataloging and physical processing are treated in particular demonstrating that accepted library practices can be flexible enough to allow adaptation for both the individual library and its specific clientele realistic methods of handling the many different kinds of nonbook materials are demonstrated by treating each type separately many easy to  follow cataloging examples are presented and consistent with established library routine practical information is provided on selection acquisition physical processing storage and equipment work flow charts are included to present a graphic demonstration of efficient procedures
CISI	the development of reference services through academic traditions public library practice and special librarianship modern american library history has received only sporadic attention as a subject for investigation though we have now accumulated an adequate supply of source materials to draw upon in the form of annual reports service studies biographical accounts and chronicles of individual libraries no one has yet fashioned out of these materials a critical history of american librarianship to paraphrase leo lamontagne we have salvaged remnants from the past but we have yet to convert them into history the lack has cost the profession dearly even a casual survey of the literature of librarianship reveals the shocking degree of duplication and naivete that stem from an insufficient awareness of previous efforts there is clearly room and need for a series of evaluative studies of the development of american library services which could eventually be put together to form the desired definitive history of american librarianship the present dissertation is intended as a contribution toward that end it undertakes to furnish the historical background for one of the continuing problems of american librarianship   the provision of reference services in research libraries
CISI	dewey decimal classification the schedules of edition 18 like those of 17 are based on the principle of subject integrity both the subject matter and the notation are hierarchical so that what is true of a given whole is true of all its parts the schedules are developed according to logical principles so that the classifier is guided to make correct decisions the terminology of the classification scheme reflects the terminology used by the literature being classified for ease of use this edition includes many more example notes more detailed and precise instructions and freer use of laymans terminology than did its immediate predecessor since this edition is intended for use as a shelf arrangement system for general libraries of all sizes its fulness is based upon the number of titles that large libraries may be expected to acquire in various fields since it is also intended for use in classified catalogs and bibliographies for which the dewey decimal classification is increasingly in demand in many countries it contains an increased number of provisions for number building
CISI	diffusion of abstract and indexing services for government   sponsored research during the last several decades science and technology have undergone a drastic transformation the enormity and depth of this transformation can be measured in many ways it can be measured in terms of the number of students enrolled in graduate and undergraduate schools offering degrees in the physical and applied sciences in terms of the number of new devices products and innovations introduced into the military establishment and into the civilian sector of our economy in terms of the number of scientists and engineers employed by industry and public and private institutions in terms of the amounts of money expended annually on research and development in terms of the number of technical reports books journals papers reprints and conference proceedings stemming from these expenditures and in many other ways
CISI	diffusion of innovations this book is directed both to advanced college students enrolled in sociology courses and to students of the other social sciences such as anthropology economics history and psychology who are concerned with diffusion for this reason sociological concepts are defined when they are introduced more than five hundred publications on the diffusion of innovations are reviewed here the innovations studied range from new drugs among physicians to hand tools among primitive tribes and from driver training among public high schools to hybrid corn among farmers although a generally consistent set of findings has emerged from these studies a search of the literature shows little attempt to summarize and evaluate available results and theories on the spread of ideas this volume synthesizes these findings and theories
CISI	directory of data base in the social and behavioral sciences as one of the early members of the computer community i have been keenly interested in the development of quantitative methodologies in the social and behavioral sciences and their encouragement by the data processing environment the economists with an already established mathematical orientation were among the earliest beneficiaries of the machine technology that enhances their ability to construct the test models of economic behavior today statistical methods have so affected many disciplines that it is not unusual for doctoral programs to accept statistical techniques as a substitute for one foreign language similarly the ability to program in an appropriate language is also frequently as acceptable as french or german in providing the research skills needed by doctoral students at the city university of new york and at other universities the chief function of this directory in terms of academic supplies of data is not to reinventory the social science data archives that are well known to the academic community not to duplicate the announcements of holdings that they themselves make available to their members the reason for mentioning them and indicating the nature of their holdings is to make this kind of data resource known to those researchers either in or out of the university who are not sufficiently aware of these important resources
CISI	the disadvantaged and library effectiveness the report is concerned with the social utility of libraries and with the factors that appear to be requirements for effective programs in the absence of established standards or criteria for measuring program effectiveness we have substituted a comparative analysis of a number of programs based on detailed observation of the program process a survey of needs and interests of the target groups both users and nonusers and an assessment of the librarys role in the target neighborhood as it is perceived by other community institutions serving the same groups thus a basis for comparisons and for judgements has been introduced which provides a foundation for suggestions as to the direction in which programs of service to the disadvantaged might move to achieve the study objectives library programs and practices in low income neighborhoods were examined in a number of cities in each of fifteen cities data were collected through interview and observation in four subject areas 1 the needs and interests of the community residents 2 library services in relation to other available community resources 3 the nature and scope of the neighborhood library program and its relation to the rest of the library system and 4 available measures of the impact or effectiveness of the program
CISI	documentation more than half a century ago la fontaine and otlet started their lives work which at first was connected with the term bibliography but to which gradually the work documentation was attributed what they developed was of a far wider scope than the establishment of a new technique dealing with printed and non printed documents the great deal which inspired them and those who worked side by side with them was to render accessible the totality of what is crystallized from human thought and to make of it a common treasure of mankind serving to bring mutual comprehension and to build for peace by the co operation of all men of goodwill of all nations it was in this spirit that my friend bradford joined those men whose noble faces have passed and to whom it never was given to see the achievement of the work to which they devoted their lives and it was in this spirit that bradford thanks to his knowledge and experience as scientist as well as librarian not only gave his strong and valuable support to the common work but added to it fundamental and constructive new elements just for this reason the present book we owe to him gives far more than a mere compilation of facts and experiences such a compilation would indeed be welcome because curiously enough up to now there is no good general treatise on documentation available but his book gives us before all things an abundance of original ideas and creative thoughts
CISI	documentation the current need for a manual of copying methods dealing with the processes methods techniques and types of equipment which can be used for reproducing documents of a great many different kinds arises from two factors 1 the great importance of document reproduction processes in the acquisition preservation dissemination and communication of information vital to the conduct of research work in all fields of human endeavor and on an international scale 2 the complexity of the field of document reproduction today which has resulted from the enormous technical advances made in the past fifteen years
CISI	documentation since the first publication of this work dr bradford has died and a further edition now being called for an attempt has been made to recognize if not to deal with some criticisms expressed on the first edition the principal one was that whereas the book was entitled documentation it dealt in the main with the universal decimal classification which bradford did much to develop but that it neglected other aspects and instruments of the subject of which the udc is only one even if an important one of various techniques
CISI	document information analysis this book considers nature and properties of document information information characteristics of documents the types and functions of constituents of traditional auxiliary apparatus discusses formalization of document information considers continuous classificatory rank of formalization document sequences from questionnaire distribution to matrix documents
CISI	dynamic information and library processing among the various information processing tasks which may be carried out with computing equipment a special class exists for which the term information takes on the literal and direct sense of recorded knowledge or intelligence the elements being transformed are then no longer restricted to mathematical symbols alone but they may be words and phrases books documents pictures and other information carriers it is that more restricted interpretation of an information process which gives rise to the field of information science concerned with the collection analysis classification storage retrieval transmission and dissemination of recorded data and intelligence
CISI	economic analysis of the public libraries this study addresses itself to several questions important to all public libraries how should the library allocate its book budget what kinds of books should it tend to buy what types of households use the library why do some households not use the library what is the cost of the various services provided by the library what specific steps can the library take to improve its services what are the librarys options in choosing among the different circulation systems for how long should the library allow books to be checked out how frequently should overdue notices be sent out is an investment in a security system worthwhile we have studied these questions in the context of one public library   the beverly hills california public library   and have developed a methodology for determining answers to them as well as to other questions that arose during our investigation although answers will vary from library to library our methodology is quite general and should prove useful at many public libraries
CISI	economics of the academic libraries this volume represents what we believe to be as complete and thorough an analysis as possible of the available economic data on college and university libraries in the course of our study we have examined the data for comprehensiveness and consistency we have investigated their intertemporal behavior both as a basis for projection and as an instrument for long range planning and we have constructed a set of analytic interrelationships which permit us to derive statistical estimates of the interrelations of some of the most critical economic variables relating to library operations in particular in the course of this last step we have provided relationships explaining statistically the determination of such variables as the size of libraries budgets and the magnitude of their professional staffs
CISI	economics of approval plans current budget strains on college and university libraries require a stepped up search for operating economies the timely topic of economics of approval plans of the third international conference on approval and gathering plans for large and medium size academic libraries held at the ramada inn west palm beach florida february 17 19 1971 has thus generated considerable interest the papers published here constitute by and large original research in this area the importance of these contributions can hardly be overestimated since they will no doubt mold and influence collection development practices in the current imprint area
CISI	economics of book storage this report attempts to present and interpret current winter 1968 69 information on the economics of book storage in relation to the other factors a university administrator must consider in developing a program for housing an ever growing book collection when there are present or future limitations on space and money the study will attempt to answer two specific questions 1 is it economical for colleges and universities to select so called little used books from the regular bookstacks and store them elsewhere 2 is the cost factor the only one a university need consider in adopting a storage program and if not how is cost related to the others the facts and conclusions in this report are based on the library book storage situation as of 1969 innovations in computer applications and other technologies could presumably change the nature of some of the cost factors but it is the authors opinion that these changes unlikely to occur within the next 5 to 10 years
CISI	economies and computers it is not a simple matter to describe this book briefly it attempts to provide and apply a set of concepts from economic theory that may prove valuable to those who are now or may become decision  makers in the selection financing and or use of computers only theory relevant for such decision makers is presented here this means that the effects of computers on the economy as a whole lie outside the scope of this book as do a number of related issues we deal thus with microeconomic not macroeconomic theory our focus is on the small industry firm computer and not the large gross national product consumer price index unemployment
CISI	economics of defense in the nuclear age the purpose of this book is to explain a way of looking at military problems which we and others with whom we have been associated have found fruitful in insights and productive of solutions essentially we regard all military problems as in one of their aspects economic problems in the efficient allocation and use of resources we believe that this way of looking at military problems goes far toward reconciling the apparent conflict of views between the officers and officials who are responsible for defense and the officials and congressmen whose primary interest is economy   except in determining the over all size of the military budget where conflict between these points of view is inevitable
CISI	educating the library user educating the library user is a collection of original essays case studies and research reports on the problems hopes and techniques of instructing library users and nonusers from the kindergartener to the preschool adult in the effective use of libraries and their resources merging the library use teachings of school public and academic libraries this book demonstrates the need for a consistent sequential plan of library use instruction that crosses traditional library boundaries
CISI	education and training for scientific and technological library and information work the exponential growth of the literature of science and technology is a phenomenon which scientists have been living with for the past 300 years it is in the nature of such growth that its effect is recognized only slowly but when a critical point is reached its consequences can be overwhelming in science information this point has now been reached to take but one field chemistry it took well over two centuries for the first million papers to be published and over 30 years from 1907 to 1938 for the first million to be abstracted in chemical abstracts we are now at the stage where one million papers have been abstracted in a five year period   1962 1967   and before 1975 the point will have been reached where one million papers equal to the output of the whole pre war generation of chemists will be published and abstracted in a single year the first scientific serial began publication in 1665 some 290 years later in 1956 the science museum library was receiving 9 000 current scientific serials within only a further 11 years the national lending library for science and technology n l l was receiving over three times this number the growth in the use of scientific literature is no less spectacular thus for example in 1930 the number of loans by the science museum library was 10 000 in 1967 the n l l which had taken over the national lending function of the science museum library lent well over half a million items a total exceeding that of all the loans by the science museum library between 1929 and 1947 a period which itself saw the discovery of nuclear fission and its application for peaceful uses enormous progress in antibiotics developments in synthetic materials and great advances in all branches of science and technology there are some signs that the rate of increase implied in these examples may not be maintained but any flattening out that may develop will be at a very high level indeed
CISI	efficiency of the scientific information this book considers basic tendency of the development of information science theoretically proves necessity and feasibility possibility of determining the economical effectiveness of scientific technical information
CISI	some user requirements stated quantitatively in terms of the 90 percent library librarians publishers and information system engineers have very little verified information and few guidelines to describe the users specific requirements for information such information is needed to properly design or evaluate the information systems to date most of the statements of requirements have been rather subjective and often reflect opinion rather than actual fact relatively little objective data have been obtained this is probably due in large part to the fact that there are extremely difficult methodological problems in trying to determine and state user requirements in a meaningful manner this paper suggests an approach or point of view that might help this situation by providing a method of phrasing the statements of user requirements in a more convenient and meaningful manner this paper also furnishes several examples of such statements and discusses the techniques and data that support these statements in this paper attention is initially focused on the information requirements of workers in the field of science and technology with no serious attempt made to include workers in other fields however it seems quite likely that the approach and perhaps even the stated principles could be extended and generalized to cover other fields of knowledge
CISI	electronic data processing in the university library following five years of experience with the mechanization of procedures using data processing equipment the university library in bochum is attempting to summarize its findings a comparison with earlier publications about the use of electronic data processing equipment shows in what measure the original plans have actually been affected by the experience that has been gained this summary also serves as a report for the wider public that may be interested in technical questions of library processing
CISI	encyclopedia of information systems and services the processing and transfer of information is an important activity of many thousands of libraries research institutes educational institutions professional and trade associations non profit organizations publishing houses government agencies and others all of these groups are already listed in a variety of existing directories this publication on the other hand has selected from the above groups those organizations and services which are principally concerned with storage retrieval and dissemination of information and in addition are innovative experimental or non  conventional a major emphasis is on computerization micrographics networks advanced reference services information centers and data banks the encyclopedia of information systems and services includes descriptions of the following types of services and facilities information centers computerized systems and services networks and cooperative programs data banks documentation centers information storage and retrieval systems micrographic systems and services research centers and projects clearinghouses and referral centerss consulting and planning organizations and services information offices industrial research information centers professional associations specialized library reference services
CISI	encyclopedia of information systems and services this publication describes and analyzes approximately 1750 organizations concerned with new forms new media and new methods for providing information services among these organizations are publishers computer software and time  sharing companies micrographic firms libraries information centers and consultants the common interest of these diverse organizations is in service based on storage and representation of structured information with output on a recurring or demand basis the concept of information as used throughout this book is defined as data organized into a collection of facts and most often recorded in two basic forms 1 textual data or literature and 2 numeric data roles played by the organizations described on the following pages vary but include one or more of the following functions data base creation data base publishing data transmission data manipulation and analysis and data storage and retrieval emphasis in this publication is on organizations involved in computerized services micrographic applications selective dissemination of information sdi and networking not included in the encyclopedia of information systems and services are printed commercial and legal services traditional academic and special libraries public information offices hardware manufacturers and distributors within the computer and micrographic field conventional indexing and abstracting services and most library automation programs which are limited to such housekeeping functions as circulation serials control and acquisitions
CISI	citation indexes citation indexing is a relatively new method of organizing the contents of a collection of documents in a way that overcomes many of the shortcomings of the more traditional indexing methods the primary advantage of citation indexing is that it identifies relationships between documents that are often overlooked in a subject index an important secondary advantage is that the compilation of citation indexes is especially well suited to the use of man machine indexing methods that do not require indexers who are subject specialists furthermore citations which are bibliographic descriptions of documents are not vulnerable to scientific and technological obsolescence as are the terms used in subject indexes
CISI	dialog interactive information retrieval system dialog is the name given to an interactive computer based information retrieval language developed at the lockheed palo alto research laboratory the dialog systems consists of a series of computer programs which have been designed to make full use of direct access memory devices in which data located anywhere on the device can be accessed in approximately the same amount of time and video display units to provide the user a rapid and powerful means of identifying records within a file which satisfy the particular information need by providing the user full display access to the indexing vocabulary and the ability to modify search expressions dialog becomes a data processing extension of the human operator who directs and controls the process according to his own personal needs
CISI	sources of information on specific subjects an alternative hypothesis to be investigated is that to a considerable extent the references are scattered throughout all periodicals with a frequency approximately related inversely to the scope on this hypothesis the aggregate of periodicals can be divided into classes according to relevance of scope to the subject concerned but the more remote classes will in the aggregate produce as many references as the more related classes the whole range of periodicals thus acts as a family of successive generations of diminishing kinship each generation being greater in number than the preceding and each constituent of a generation producing inversely according to its degree of remoteness the investigation covered in the first place the references quoted in the course of four and two and a half years respectively by the current bibliographies of applied geophysics and lubrication which are prepared in the library the source of each reference being given it was possible to arrange the sources in order of productivity the results being set down in columns a and b of the table in the previous column
CISI	error correcting codes several major developments have contributed to the rapid emergence of the field of error correcting codes over the past two decades externally the cost of solid state electronic devices has decreased almost as dramatically as their size this has stimulated the development of digital computers and peripheral devices and this in turn has caused a dramatic increase in the volume of data communicated between such machines the intolerance of computing systems to error and in some cases the inherently critical nature of the data demand the use of either error free facilities or some type of error detecting or correcting code in the terminal devices in many cases the latter approach is the more economical
CISI	the evaluation of information services and products the continuing need to put scientists in contact with the research of others coupled with the rapidly expanding volume of published material during the past several decades has placed new emphasis on the old arts of assembling coding and disseminating recorded knowledge in some instances the emphasis has manifested itself in research on improvement of traditional library systems in other instances it has resulted in the assembly of specialized collections and their intensive indexing for access in a variety of ways still other systems have progressed from the passive role of responding to requests to the active role of supplying documents or references to them to researchers as the documents become available for lack of a more descriptive terminology all of these activities are referred to in this book as document transfer systems implying that the product being retrieved or disseminated is a document rather than the information if any in it that is intelligence systems or fact retrieval systems if facts are indeed retrieved are excluded from our concern the document of course may be a book a journal article a drawing an abstract a piece of film or a piece of magnetic tape
CISI	evaluation of medlars documentation this report presents the results of a detailed analysis by the national library of medicine of the performance of medlars its medical literature analysis and retrieval system in relation to 300 actual requests made to the system in 1966 and 1967 thanks to this study we now know considerably more about the requirements of medlars users how well the system is meeting these requirements and what we must do to improve the overall performance level the investigation is timely the library is now planning a second generation medlars and the design of medlars ii should benefit greatly from our knowledge of factors affecting the performance of the present system
CISI	evaluation of micropublishing micropublishing as it pertains to library materials is essentially a form of the republishing of materials no longer in print the need for such materials of many kinds   monographs serials newspapers reference works   has grown greatly during the past quarter century and this need is reflected in the growth of the micropublishing industry as new colleges and junior colleges are founded and established colleges and universities continue to expand to meet growing educational needs both groups of institutions find that in more and more instances the materials they need are available only in microform as a result the ratio of microforms to books in college and research libraries has been steadily rising
CISI	evaluation of the world food literature this publication presents the culmination of a concerted international effort to survey the relevant worlds scientific and technological literature for its food science and technology content as a preliminary step towards the establishment of a comprehensive abstracting and documentation service in this field
CISI	evaluative research principles and practice in public service and social action programs in these days of large government programs intended to reduce poverty develop communities prevent delinquency and crime control disease and reconstruct cities the predominant rhetoric is that of planning pilot projects experimental and demonstration programs   and evaluation those who seek to select for support the more promising plans and projects submitted to funding agencies have become habituated to the ritualistic inclusion in the proposal of a final section on evaluation in most cases this section consists of sometimes grandiose but usually vague statements of intent and procedure for assessing the impact of the proposed action in some cases there is an elegant highly academic and impractical scheme worked out in meticulous detail by an obviously talented research consultant in a few treasured instances there is a well considered realistic and workmanlike plan for getting some fairly reliable answers to the questions of what worked and why
CISI	informal communication in science its advantages and its formal analogues formal and informal scientific communication are complementary they must not be thought of as alternatives in the sense that perhaps certain messages are obtained exclusively through the printed word the library and the mechanized search and retrieval system whereas others are obtained by the exclusive use of word of mouth and the telephone the much more typical event is one in which the receipt of a single message is secured by the successive interplay of these two kinds of communication for any given transaction between a scientist as a receiver of information and the channel that brings him that information usually has a history behind it and a future ahead of it that may be very relevant to the evaluation of the success of that transaction and to the prognosis of whether this kind of transaction will happen again with similar results
CISI	the foundations of education for librarianship the study is a result of a theory of librarianship which has been in the process of maturation for more than a quarter century of teaching and administration first at the university of chicago and subsequently at western reserve university now case western reserve university and which has been elaborated in essays and addresses as the inquiry progressed my purpose has been to explore the role of the library as it contributes to the total communication system in society and the meaning of that role for the library profession and having determined the requirements of that role to identify those which are appropriately met by graduate professional education therefore the inquiry begins with a consideration of the communication system within the individual as related to his physiological neurological and psychological structure and its meaning for learning and reading patterns and characteristics the study then progresses to an exposition of the cultural environment and its communication system in society together with the place of the library in it
CISI	a guide to the construction and use of special schemes the use of classification in libraries is traditional and its value is appreciated for documentation and information retrieval in general other techniques such as alphabetical indexing and machine selection are also available that classification is of value in information retrieval as well as in book arrangement is however made evident in two ways first to achieve consistency and subtlety in alphabetical indexing and machine selection designers of such retrieval systems find the need to introduce classificatory techniques second there is a continuing demand for the construction of special classifications for detailed arrangement and cataloguing of documents in restricted but intensively cultivated fields of knowledge it is to help meet these demands particularly the second that this guide has been prepared the techniques of detailed depth classification have been greatly developed during the past decade and instruments of much greater subtlety and efficiency than the traditional tree of knowledge schemes can now be designed these developments have been reported mainly as research papers in a variety of library journals and are often made unnecessarily difficult to follow by the use of unfamiliar terminology there is a need for a more simply written and more readily available practical guide to the use of the newer techniques of classification
CISI	factors determining the performance of indexing systems the original aslib cranfield investigations on the efficiency of indexing systems references 1 2 and 3 did not by itself produce firm answers to what is one of the basic problems in information retrieval namely the decision as to which index language should be used certainly it did not as some people had anticipated demonstrate that one system was better than another either generally or in any given situation
CISI	factors determining the performance of indexing systems the test results are presented for a number of different index languages using various devices which affect recall or precision within the environment of this test it is shown that the best performance was obtained with the group of eight index languages which used single terms the group of fifteen index languages which were based on concepts gave the worst performance while a group of six index languages based on the thesaurus of engineering terms of the engineers joint council were intermediary of the single term index languages the only method of improving performance was to group synonyms and word forms and any broader groupings of terms depressed performance the use of precision devices such as links gave no advantage as compared to the basic device of simple coordination
CISI	factors in the transfer of technology the strong correlation between the scope and depth of this countrys research and development activities and the vigor and the growth of its industrial plant is today a widely accepted fact government expenditures for research and development have increased from a modest annual rate of 200 million some thirty years ago to 17 billion today the research budgets of the private sector of the economy which were almost miniscule in the 1930s total approximately 8 billion today these expenditures have had their many tangible and visible results ranging from nylon and antibiotics to radar and solid state electronics but what is not so generally appreciated is the additional product represented by the increasing inventory of ideas and new knowledge whose application for the most part is still a potential one the sophisticated and often urgent nature of some of the larger products in which we engage today which require vast research expenditures to find the efficient way or the economical way or the safe way or the most accurate way to accomplish some end purpose also produces an increase in the national level of scientific and technological competence that has not yet been transferred into the civilian economy the value of the technical ideas now stored and awaiting application can be estimated as a value many times larger than the annual rate of billions of dollars invested in the effort it took to develop this increased technical capability as a national resource for underwriting further economic and industrial development this technical inventory is a factor of major importance
CISI	faculty status for librarians the purpose of this study is 1 to review the history of the struggle for faculty status for librarians and some of the arguments advanced in support of that objective and 2 to gather information on the similarities and differences between librarians and faculty members in the broad areas of preparation contributions and rewards with detailed information on such matters as education salaries professional experience tenure sabbaticals participation in academic government and scholarly activity of librarians and faculty members one should be able to judge whether librarians receive unfair or unequal treatment
CISI	farewell to alexandria solution to space growth and performance problems of libraries the publication of this collection of essays opens a new era for libraries taking the first departure in 2 300 years from that durable model conceived by the librarians of alexandria and endlessly replicated by every succeeding generation of librarians right down to the present day the alexandrian model persists through the unexamined faith that to be good a library must be vast and always growing the papers presented here examine that faith scientifically demonstrate that it rests on nothing more solid than mistaken intuition and consign it to the limbo of outworn dogmas
CISI	a feasibility study of centralized and regionalized inter library loan centers the two major problems of the present system are 1 the unequal distribution of lending with a few of the largest libraries handling a large proportion of the requests and 2 the difficulty of filling requests which are incomplete incorrect or inadequately checked solutions proposed for these two problems have been 1 compensation to the largest libraries for each transaction and 2 better bibliographic checking of requests before they are forwarded to the lending library
CISI	biomedical literature volume growth and other characteristics this studys aim was to gather and analyze reliable data on the quantifiable characteristics of the biomedical literature that affects communication problems within the research community previous studies and standard bibliographic compilations were critically reviewed particularly for data that could be used to determine changes with time in addition all publications generated during 1961 1962 by the extramural and intramural research programs of the national institutes of health nih were analyzed as samples of the current document output of us research
CISI	formal languages this book develops a theory of formal languages from the point of view of generative devices mainly grammars recognition devices automata are introduced only as a secondary tool and are themselves presented within the framework of rewriting systems the main emphasis is on mathematical aspects of formal languages rather than application people interested only in applications to programming languages resp natural languages would certainly prefer a more comprehensive discussion on topics such as lr k grammars resp transformational grammars such discussions lie outside the scope of this book
CISI	formal languages and their relation to automata this book presents the theory of formal languages as a coherent theory and makes explicit its relationship to automata the book begins with an explanation of the notion of a finite description of a language the fundamental descriptive device   the grammar   is explained as well as its three major subclasses   regular context free and context sensitive grammars the context free grammars are treated in detail and such topics as normal forms derivation trees and ambiguity are covered four types of automata equivalent to the four types of grammars are described these automata are the finite automaton the pushdown automaton the linear bounded automaton and the turing machine the turing machine is covered in detail and unsolvability of the halting problem shown the book concludes with certain advanced topics in language theory   closure properties computational complexity deterministic pushdown automata lr k grammars stack automata and decidability
CISI	informal channels of communication in the behavioral sciences their relevance in the structuring of formal or bibliographic communication what are the needs being served by informal communication what can be done about giving informal communication without destroying its function for the active researcher certain of the advantages of formal communication such as general accessibility permanence etc how can formal channels be manipulated to take on the characteristics of informal communication to cast light on these questions the present paper examines the role of informal and formal channels within the overall system of scientific dissemination in psychology considers the special advantages of informal communication and outlines certain relations between informal and formal channels in a final section of the paper two experiments in scientific communication are described one experiment being built about an innovation that attempts to informalize formal channels while the other is built about another innovation that in general attempts to formalize an informal channel
CISI	functional approach the present book sums up a certain stage in the research on algebraic linguistics being pursued at charles university prague it is based mainly on p sgalls book 1967a in czech which represents the first attempt at a systematic formulation of the conception of generative description that has gradually been elaborated by our research group we do not claim that any particular question has been answered here in a definitive way but the conception of a generative system based on an articulation of the semantic relation see section 1 3 4 may perhaps be interesting in connection with the present development of algebraic linguistics this conception originated in 1963 1964 mainly as a reaction to the existing form of transformational description it has not yet been possible to take the more recent impulses into account to an extent that would be adequate to their scope and theoretical significance only some aspects of these impulses are commented on in the relevant parts of the present book we do not present a complete characterization of a system that could be regarded as a counterpart to the new version of transformational grammar we have simply tried to formulate a conception that can serve as a starting point for the development of a new alternative
CISI	future developments in telecommunications communication technology has entered a period of revolutionary change the last decade has brought new inventions of enormous potential it will probably be two decades before we fully grasp the shattering effect they will have on society these inventions include the communication satellite suddenly this has provided telephone and television links to the underdeveloped world much larger satellites will be built and will have an enormous impact on education and communications both in the united states and throughout the world the satellite antennae in some underdeveloped countries stand next to fields ploughed by oxen the helical waveguide a pipe now operating that can carry 250 000 simultaneous telephone calls or equivalent information over long distances the laser this means of transmission still in the research laboratory has the potential of carrying many millions of simultaneous telephone calls or their equivalent large scale integration lsi a form of ultraminiaturized computer circuitry that probably marks the beginning of mass production of computers and computerlike logic circuitry it offers the potential of extremely reliable extremely small and in some of its forms extremely fast computers if large enough quantities can be built this circuitry can become very low in cost on line real time computers computers capable of responding to many distant terminals on telecommunication lines at a speed geared to human thinking they have the potential of bringing the power and information of innumerable computers into every office and eventually every home picturephone a public dial up telephone system in which subscribers see as well as hear each other large tv screens tv screens that can occupy a whole wall if necessary cable tv provides a cable into homes with a potential signal carrying capacity more than one thousand times that of the telephone cable it could be used for signals other than television voice answerback computers can now assembly human voice words and speak them over the telephone this fact coupled with the touchtone telephone set makes every such telephone a potential computer terminal millimeter wave radio radio at frequencies in the band above the microwave band can relay a quantity of information greater than all the other radio bands combined chains of closely spaced antennas will distribute these millimeter wave signals pulse code modulation all signals including telephone picturephone music facsimile and television can be converted into digital bit stream and transmitted along with computer data over the same digital links major advantages accrue from this computerized switching computerized telephone exchanges are coming into operation and computer like logic can be employed for switching and concentrating all types of signals data banks electronic storage for huge quantities of information that can be manipulated and indexed by computers and that can be accessed in a fraction of a second
CISI	future shock this is a book about what happens to people when they are overwhelmed by change it is about the ways in which we adapt   or fail to adapt   to the future much has been written about the future yet for the most part books about the world to come sound a harsh metallic note these pages by contrast concern themselves with the soft or human side of tomorrow moreover they concern themselves with the steps by which we are likely to reach tomorrow they deal with common everyday matters   the products we buy and discard the places we leave behind the corporations we inhabit the people who pass at an ever faster clip through our lives the future of friendship and family life in probed strange new subcultures and life styles are investigated along with an array of other subjects from politics and playgrounds to skydiving and sex
CISI	the government of the american public library the major purpose of this study is to describe analyze and evaluate the position of the public library in the structure of government in the united states the use of the word government in the title therefore is deliberate we are here concerned with the legal forms and types of governmental organization of the public library and with its relation to the city or other political unit to which it is attached or which it serves
CISI	government publications a guide to bibliographic tools the expansion of government at all levels   international national provincial or state and local   has resulted in increasing government influence on the life of each citizen concomitant with this development is the proliferation of published directives regulations reports technical studies and other informational issuances in such volume that no one engaged in a business or profession no financial tycoon educator researcher farmer housewife welfare recipient or unemployed person can function without some reference to government publications yet in few areas of recorded human knowledge have control and bibliographic aids been so little systemized the present work designed to provide the prospective user as well as the trained researcher and librarian with a guide to the maze is a direct descendant of the childs essay the extent to which the mass of published material has grown is underscored by the contrasting physical size of the two publications childs was a 78 page pamphlet containing approximately 400 entries whereas this book of over 400 pages cites more than 3 000 titles
CISI	a guide to the library of congress classification this guide is an introduction to the library of congress classification as such it does not include instructions for every subclass or table but attempts to provide the reader with an understanding of the characteristics of the classification the arrangement within the classes the format of the schedules and tables and special problems of use and notation the reader should trace the analysis of each example of classing through the pages from the l c schedule provided in the guide it is important to remind the reader that a thorough study of each class schedule in addition to the recommended readings is essential the author realizes that many imperfections may be present in this guide and will appreciate suggestions for changes from readers
CISI	guide to reference books the fundamental principles of reference work remain more or less constant through the years but the rapid expansion of the publication of reference books in all fields makes essential a careful selection to fit the needs of each library the purpose of this volume is to list reference books basic to research   general and special   and thus to serve as 1 a reference manual for the library assistant research worker or other user of library resources 2 a selection aid for the librarian and 3 a textbook for the student who either in library school training class or college course in bibliography is pursuing a systematic study of reference books the needs of these types of users have influenced the organization and make up of this volume in that the requirements of the first two groups have made the manual more comprehensive than it might have been if intended for a textbook only while the introductions to sections and many of the annotations have been provided particularly for the library school student
CISI	guidelines for library automation a handbook for federal and other libraries this book is one of the products of a contract initiated by the automation task force of the federal library committee sponsored and monitored by the u s office of education and carried out by the system development corporation the project included a questionnaire survey of all federal libraries 2104 as of december 1970 to gather systems planning data and to identify federal libraries with operational or planned automated systems respondents in the latter group were sent a federal library automation survey questionnaire requesting specific details about existing and planned systems from these sources amplified by visits to federal libraries and an extensive review of the automation literature information was distilled for use in this handbook
CISI	handbook of comparative librarianship the first part written by myself deals with comparative librarianship and comparative method and is intended for both teachers of comparative librarianship and their students it can be approached in a number of ways the first three chapters outline comparative librarianship and the theoretical basis of its methodology against the wider background of other comparative sciences and the scientific method the three chapters following are purely practical and explain the various steps of writing a comparative study the last chapter is intended for teachers the second part compiled by mrs mackee is a bibliographical guide to the main sources on librarianship throughout the world it draws on the bibliographies collected by comparative librarianship students in the course of their project work on replies to a questionnaire sent to the various library associations of the world and on mrs mackees own collection of references gathered over a number of years
CISI	handbook of data processing for libraries the purpose of this book therefore is to assist libraries and librarians in resolving some of the problems faced in utilizing this new technology the intent is to provide a concrete factual guide to the principles and methods available for the application of modern data processing to library operations for the operating librarian it should be considered a handbook a tool to guide him in decisions concerning the introduction of data processing techniques into his own library for the student it should be a textbook educating him not only in methodology but also in the interrelationships between data processing and the library for the system designer it should be a summary of the state of the art serving as a bridge between library objectives and the technology the book throughout lays special stress on the library and particularly on the significance of library values and policies for determining the choice of system the book gives emphasis to the computer but always in the context of applying this technology to the solution of operating problems as an addition to resources for information service as a tool of good management and not as an end in itself at most therefore the book aims to educate the profession in the use of these tools and in the special problems of applying them to libraries in this respect much of the groundwork has already been done   the profession has been educating itself has carried out analyses of library operations has experimented with mechanization and is developing better concepts of cost control the book merely continues a process that is already underway
CISI	hdb of data processing for libraries the four years since the first edition of this book was published have been a period of exceptional advance in the usage of computers in libraries where one or two examples were all that were available at that time to illustrate each kind of application now there are five to ten where the cadre of knowledgeable people in libraries at that time was small now virtually every major library has some kind of systems department where the efforts at that time were largely experimental and developmental now there is a wealth this second edition has therefore been written in a context totally different from that of the first but its aims are the same to ensure that practicing librarians and that students in library schools approach the world of automation with knowledge of its capabilities and limitations and with the techniques of systems analysis by which to analyze and evaluate alternative answers to the librarys processing problems the changes from the first edition therefore represent not a departure from that purpose but simply an updating of its content to reflect the advances and experience gained and an opportunity to correct the errors hopefully minor that have been found through use of the first edition
CISI	handbook of medical library practice the medical library association has long been aware of the need for a third edition of the handbook changes in library practices proliferating demands upon established libraries and the development of new ones created the need of an up to date tool like the earlier editions this handbook is such a tool a manual not a survey of the state of the art it offers practical advice to all   fledgling librarians starting their careers experienced librarians transferring to the field of health sciences established medical librarians refreshing memories or adopting procedures unfamiliar to them and specialists in related fields
CISI	handbook of the national and international libraries two methods were used 1 a thorough search of professional literature principally since 1965 with exceptions in cases where no later information was available and 2 direct communication with associations through a questionnaire and consultation of supplementary material provided by the associations the final result of the authors search was a total of 319 library associations 33 international in scope and 286 national see statistical data
CISI	the hidden dimension generally speaking there are two types of books of interest to the serious reader today those that are content oriented designed to convey a particular body of knowledge and those that deal with structure the way in which events are organized it is doubtful if an author has any control over which of these two types of books he writes though it is desirable that he be aware of the difference the same applies to the reader whose satisfaction depends largely on his unstated expectations in todays world when all of us are overwhelmed with data from many sources it is easy to understand why people are apt to feel that they are losing touch with developments even in their own field one senses that there is also a growing awareness of a loss of relatedness to the world at large this loss of relatedness leads to an increased need for organizing frames of reference to aid in intergrating the mass of rapidly changing information with which man must cope the hidden dimension attempts to provide just this
CISI	historical introduction to library school this is a revision and enlargement of origins of the american library school someone has observed that the roots of the present lie deep in the past and must be uncovered to understand fully how the present came to be what it is this study is less a descriptive history of library schools and their work than a search for perspective within which major problems as well as the course pursued in resolving them can be more fully understood the original study begun in 1941 42 sought to throw light on how library education at that time came to be what is was the present study continues beyond the early forming of the american library school to the reforming of basic lines of policy and organization a new title is used to reflect the broadened scope
CISI	the history of libraries in the western world the present work is an attempt to trace the history of libraries in the western world to indicate how libraries developed and how they influenced the social and cultural history of our civilization the book is intended for the student of library science or of cultural history and for the general reader interested in the development of western civilization much has been omitted concerning libraries and librarians that could have been included conversely some facts could have been omitted without seriously detracting from the story as a whole but have been included to illustrate how library history developed they point out the high spots and indicate trends
CISI	90 recommended journals for the hospitals health science library choosing from the growing number of medical and paramedical journals is becoming increasingly difficult for the health science librarian the author states she describes a survey of librarians and directors of medical education to obtain recommendations on titles to form a core journal collection and lists in order of preference the 90 top ranking titles
CISI	human behavior and the principles of least effort an introduction to human ecology nearly twenty five years ago it occurred to me that we might gain considerable insight into the mainsprings of human behavior if we viewed it purely as a natural phenomenon like everything else in the universe and if we studied it with the same dispassionate objectivity with which one is wont to study say the social behavior of bees or the nestbuilding habits of birds the present book reports the results of the extended inquiry that ensued in the course of those years and which led to the disclosure of some fundamental principles that seem to govern important aspects of our behavior both as individuals and as members of social groups
CISI	human problem solving the present study is concerned with the performance of intelligent adults in our own culture the tasks discussed are short half hour moderately difficult problems of a symbolic nature the three main tasks we use   chess symbolic logic and algebra like puzzles called cryptarithmetic puzzles   typify this class of problems the study is concerned with the integrated activities that constitute problem solving it is not centrally concerned with perception motor skill or what are called personality variables the study is concerned primarily with performance only a little with learning and not at all with development or differences related to age finally it is concerned with integrated activities hence deemphasizes the details of processing on the time scale of elementary reactions that is half a second or less similarly long term integrated activities extending over periods of days or years receive no attention
CISI	the human side of enterprise this volume is an attempt to substantiate the thesis that the human side of enterprise is all of a piece   that the theoretical assumptions management holds about controlling its human resources determine the whole character of the enterprise they determine also the quality of its successive generations of management of course the process is circular and herein lies the possibility and the hope of future progress the key question for top management is what are your assumptions implicit as well as explicit about the most effective way to manage people from the answer to this question flow the answers to the questions mr sloan raised in our discussion about the making of managers as well as answers to many other questions which perplex and confound management as it seeks to achieve more successfully the economic objectives of enterprise it will be clear to the reader that i believe many of our present assumptions about the most effective way to manage people are far from adequate
CISI	a statistical approach to mechanized encoding and searching of literary information written communication of ideas is carried out on the basis of statistical probability in that a writer chooses that level of subject specificity and that combination of words which he feels will convey the most meaning since this process varies among individuals and since similar ideas are therefore relayed of different levels of specificity and by means of different words the problem of literature searching by machines still present major difficulties a statistical approach to this problem will be outlined and the various steps of a system based on this approach will be described steps include the statistical analysis of a collection of document in a field of interest the establishment of a set of notions and the vocabulary by which they are expressed the compilation of a thesaurus type dictionary and index the automatic encoding of documents by machine with the aid of such a dictionary the encoding of topological notations such as branches structures the recording of the coded information the establishment of a searching pattern for finding pertinent information and the programming of appropriate machines to carry out a search
CISI	the automatic creation of literature abstracts experts of technical papers and magazine articles that serve the purposes of conventional abstracts have been created entirely by automatic means in the exploratory research described the complete text of an article in machine  readable form is scanned by an ibm 704 data processing machine and analyzed in accordance with a standard program statistical information derived from word frequency and distribution is used by the machine to compute a relative measure of significance first for individual words and then for sentences sentences scoring highest in significance are extracted and printed out to become the auto abstract
CISI	a business intelligence system an automatic system is being developed to disseminate information to the various sections of any industrial scientific or government organization this intelligence system will utilize data processing machines for auto  abstracting and auto encoding of documents and for creating interest profiles for each of the action points in an organization both incoming and internally generated documents are automatically abstracted characterized by a word pattern and sent automatically to appropriate action points this paper shows the flexibility of such a system in identifying known information in finding who needs to know it and in disseminating it efficiently either in abstract form or as a complete document
CISI	on some clustering techniques the problem of organizing a large mass of data occurs frequently in research normally some process of generalization is used to compress the data so that it can be analyzed more easily a primitive step in this process is the clustering technique which involves gathering together similar data into a cluster to permit a significant generalization this paper describes a number of methods which make use of ibm 7090 computer programs to do clustering a medical research problem is used to illustrate and compare these methods
CISI	r and d project selection where we stand a review of the literature on r and d project selection and an analysis of interview data suggest that there is a lack of testing and use of the methods proposed several or ms methods are identified and their current status is indicated three representative procedures are examined in some detail it is argued that both a lack of testing concerning feasibility and shortcomings of the models themselves help to explain why the methods have not been used some of these shortcomings are identified and discussed implications for future research are presented
CISI	a method for allocating r d expenditures the analytical problems of developing quantitative techniques for r d investment management are often complicated by the existence of conflicting goals corporate goals may require the r d manager to simultaneously seek the highest probable profits the largest probable number of successes and the greatest probable profit per dollar spent departmental goals may restrict the manager to some maximum budget a minimum number of projects to be worked on and minimum levels of accomplishment on specific projects in a sense then the research manager is faced with a constrained multiple output production problem how much to spend on which project and how much to spend overall this paper shows how a slight modification of hess approach to project selection and an analogy to the theoretical economics of a multiple product factory have been used to help our research management simultaneously solve these project selection resource allocation and budget determination problems most approaches in the literature have treated these three problems separately
CISI	the selection of r d program content survey of quantitative methods this paper presents a summary of methods of evaluating and selecting r d projects approximately thirty methods which have appeared is scattered places in the literature are described briefly and a bibliography is provided for further information the various methods are compared and contrasted with each other relative to a standard set of features which they may possess to a standard set of characteristics relating to ease of use and to scientific or technological area of applicability
CISI	the effects of perceived need and means on the generation of ideas for industrial research and development projects a flow model is presented which identifies some of the organizational factors influencing idea generation behavior in industrial r d laboratories the model is constructed from literature based propositions which make explicit the role played by several organizational factors identified in the model data were collected on about 300 ideas created in a divisional laboratory of a major u s corporation in general these data support the a priori propositions further data analysis suggests that two pieces of information are required before an idea is generated 1 knowledge of a need problem or opportunity relevant to the company and 2 knowledge of a means or technique for satisfying the need solving the problem or capitalizing on the opportunity these results are discussed with respect to the stage of creative thought proposed by other investigators finally the organizational events which were associated as needs events or means events for the ideas studies are identified and analyzed with respect to both quantity and quality of ideas
CISI	the validity of subjective probability of success forecasts by r d project managers models and techniques to aid management in planning controlling r d projects frequently use subjective probability of success forecasts as one of the major inputs an experiment was conducted at the research laboratories of monsanto company to measure the predictive validity and consistency of such forecasts the results indicate that the eventual success or failure of certain types of r d projects can be predicted by measuring the time shape of polled probability of success forecasts probability of success forecasts appear to yield more valid advance warning indicators than several commonly used project status measures these results tend to support the hypothesis that r d planning and control models that are based on subjective probability estimates may reliably be used by management to aid in early identification of eventually failing projects as well as to aid in project selection and project funding
CISI	analysis of some portfolio selection models for r d this paper presents the analytical review of mathematical programming models that have been proposed as aids to the related problems of resources allocation and project selection in r d the models are classified according to whether they are based on linear integer chance constrained or dynamic programming representative examples from these classes are described and evaluated in detail the evaluation is on terms of data requirements built in assumptions ease of computation usefulness of outputs versatility of application
CISI	the information content of titles in engineering literature since many alerting and information services rely very heavily on the use of titles to transfer information to the potential user it is essential that he be aware of the proportion of the information contained in the complete document which will not be deducible from the title and which he will therefore miss methods will be discussed for analyzing the relative information content of the titles of engineering paper and results presented for the amount and type of information lost through scanning title listing only between one third and one half of indexable terms are not retrievable from article titles even if all possible synonyms and related terms are used if all synonyms are used instead of one keyword the amount of information retrieved is increased by about 70 percent the problems of dealing with synonyms and with syntactical variants in searching titles indexes are discussed the possibility of using keywords in journal titles as supplementary retrieval tags is suggested since they were deemed useful in nearly one third of the sample of papers analyzed
CISI	on fuzzy mapping and control a fuzzy mapping from x to y is a fuzzy set on x y the concept is extended to fuzzy mappings of fuzzy set on x to y fuzzy function and its inverse fuzzy parametric function fuzzy observation and control set theoretical relations are obtained for fuzzy mappings fuzzy functions and fuzzy parametric functions it is shown that under certain conditions a precise control goal can be attained with fuzzy observation and control as long as the observations become sufficiently precise when the goal is approached
CISI	cooperation between types of libraries an annotated bibliography 1969 1971 supplement this bibliography is designed to supplement capitalize between types of libraries 1940 1956 an annotated bibliography by ralph h stenstrom the staff of the library research center at the university of illinois in cooperation with the illinois state library plans to issue an annual supplement which will appear in illinois libraries each year it is hoped the supplements issued in this manner can be cumulated periodically and issued in monograph form
CISI	illustrative computer programming for libraries illustrative computer programming is intended as a graded workbook or text supplement containing typical practical problems suggested solutions and tried analyses which emphasize programming efficiency and some of the major features of pl i programming language one as such it can be used alone or in combination with established pl i textbooks such as those listed in the selected bibliography programmers with knowledge of other languages will not be bothered by excessive introductory material while beginners can learn much by looking at the solutions to the problems and their accompanying analyses
CISI	improving access to library resources the motivation for this investigation derived from a series of visits to institutions which were deeply committed to the design development and operation of non traditional automated information systems at the time of the visits the systems seemed to be working technically but paradoxically they did not appear to have made a significant impact on the respective user communities although few people associated with the systems openly expressed concern there were non verbal indicators which suggested that some people were becoming nervous since all of the systems represented high expenditures of time and money a feeling of uneasiness seemed quite appropriate
CISI	indexing languages and thesauri construction and maintenance this book has two objectives first to reassess thoroughly the functions of an indexing language or thesaurus in a information storage and retrieval system and in the light of this reassessment to analyze the structure of indexing languages and thesauri most importantly this reassessment is based on a unified view of indexing languages classification schemes and thesauri as information storage and retrieval systems on the other it results in general principles that are applicable to a wide range of situations
CISI	industrial dynamics this book is intended for the student of management whether he is in a formal academic program or in business it treats the central framework underlying industrial activity the goal is enterprise design to create more successful management policies and organizational structures
CISI	industrial research and technological innovation an econometric analysis after many years of neglect technological change is receiving the attention from economists that it deserves the 1960s being a time of a enormous interest in this area in academic government and business circles central to the economics of technological change is the manner in which new processes and products are conceived developed commercialized and accepted to help promote a better understanding of this process i have been engaged for a number of years in a series of related econometric studies of industrial research and technological innovation the purpose of this book is to bring together the results of these studies
CISI	industry and technical progress this book is written in the belief that the full and speedy application of science in industry is necessary to economic progress and should indeed be one of the most important objectives of national policy this being so it is important to identify the hindrances to speedy application many people have already drawn attention to particular hindrances but the three bodies which have sponsored this report did not consider that there was any up to date assessment of the problem which attempted to look at it as a whole in all its variety and complexity hence the investigation which they undertook and largely entrusted to us an investigation which through the great goodwill of many people in british industry has yielded so much material that this book can only be a first impression and summary
CISI	inequality a reassessment of the effect of family and schooling in america this book summarizes the results of three years of research at the center for educational policy research the eight coauthors were all research associates at the center and our work there was a collaborative effort we plagiarized both ideas and data from one another most of us also spent a good deal of time criticizing one anothers work while each of us took primary responsibility for certain lines of inquiry and this responsibility is recorded in appropriate footnotes we see our research as an integrated effort which should bear all our names
CISI	research studies in patterns of scientific communication i general description of research program this article is the first in a series which described the general procedures and some findings of over seventy studies which we conducted from 1966 to 1971 on the information exchange activities of over 12000 scientists and engineers in a sample of nine physical social and engineering sciences we designed the studies so that a the full spectrum of scientific communication media could be explored b the various studies were coupled in order that data obtained from one study could be directly related to those obtained from other studies c the scheduling of the studies was conducted in real time in order that the same body of information could be followed from its inception to its final integration into the general body of scientific knowledge and d the same studies were conducted for all nine disciplines being studied in order that genuine comparisons could be made among them the data are now stored on machine readable magnetic tapes and will be made available to scholars in the field of information science
CISI	research studies in scientific communication iv the continuity of dissemination of information by productive scientists this article is the last in series which describes a set of studies which were conducted over a 4 5 year period 1966 1971 the series of articles sought to describe a comprehensive picture of the dissemination and assimilation of scientific information as it flows through various informal and formal media from the time a scientist initiates his work until it is published the present article examines the continuity of scientific work and information exchange by productive scientists two years after the publication of their articles in 1968 1969 the results indicate that about half of the authors had changed to a subject matter area which differed from that of their earlier articles however such shifts did not decrease authors productivity nor greatly increase their information needs
CISI	inference and disputed authorship we apply a 200 year old mathematical theorem to a 175 year old historical problem more to advance statistics than history though problems of disputed authorship are common in history literature and politics scholars regard their solutions as minor advances for us the question of whether hamilton or madison wrote the disputed federalist papers has served as a laboratory and demonstration problem for developing and comparing statistical methods while we help solve this historical problem our practical application of bayes theorem to a large analysis of data is a step in testing the feasibility of a method being explored with fresh attitudes and fresh mathematics furthermore large practical applications have until now been few and our work helps fill that gap
CISI	storage analysis of a compression coding for document data bases analysis is made of the effect of using an efficient code of compression of terms within a document data base the storage efficiency is expressed in terms of the vocabulary length and the values of certain parameters which describe the structure of the code for vocabularies of up to 100 000 terms the average code length is approximately twelve bits no information is lost through term truncation or abbreviation the tables required for coding and decoding may be ordered for rapid access without reduction in the ease of update
CISI	quantitative fuzzy semantics the point of departure in this paper is the definition of a language l as a fuzzy relation from a set of terms t x to a universe of discourse u y as a fuzzy relation l is characterized by its membership function ml t u   0 1 which associates with each ordered pair x y its grade of membership ml x y in l given a particular x in t the membership function ml x y defines a fuzzy set m x in u whose membership function is given by mm x y ml x y the fuzzy set m x is defined to be the meaning of the term x with x playing the role of a name for m x if a term x in t is a concatenation of other terms in t that is x x1 xn xi t i epsilon 1 n then the meaning of x can be expressed in terms of the meanings of x1 xn through the use of a lambda expression or by solving a system of equations in the membership functions of the xi which are deduced from the syntax tree of x the use of this approach is illustrated by examples
CISI	on relevance as a measure relevance is defined as a measure of information conveyed by a document relative to a query it is shown that the relationship between the document and the query though necessary is not sufficient to determine relevance
CISI	a definition of relevance for information retrieval the concept of relevance sometimes also called pertinence or aboutness is central to the theory of information retrieval unfortunately however there is at present no consensus as to how this notion should be defined the purpose of this paper is to propose and defend a definition of what it means to say that a piece of stored information is relevant to the information need of a retrieval system user the suggested definition explicates relevance in terms of logical implication for one yes or no question answering system which operates with one of the standard formalized languages the definition provides a mathematically precise criterion of relevance for other types of fact retrieval systems and reference retrieval systems including all systems whose stored information is expressed in natural language the definition is not mathematically precise but is nevertheless still helpful on a conceptual level
CISI	computer assisted indexing the paper describes a technique which enables an on line computer based information retrieval system to aid the indexers by selecting possible index terms to be assigned to a new document entering the system the method analyses the index terms assigned to the references cited by the new article this produces a list of index terms weighted according to their expected correlation with the subject matter of the new article thus the indexer is presented with the weighted list of proposed indexing terms as an aid an evaluation is made of the results produced by the technique for a trial set of documents these documents have already been indexed for the medlars system the list of actual index terms for this trial set of documents is compared with the set of index terms proposed by the technique for each document the results of this comparison are encouraging and they are discussed in the paper the economic aspects of implementing the technique in a working information retrieval system is considered this included the expected benefits and an estimate of the cost of using the technique as an aid in terms of computer time and indexer time
CISI	a note on the concept of relevance two recent articles in this journal konigova 1 cooper 2 have gone beyond the usual slapdash use of the words relevant and relevance and have attempted to explicate the concept further both attempts only partially succeed konigova proposes three types formal relevance subject content relevance and subjective relevance or pertinency this classification has validity but is not further elaborated and indeed she reverts to a less precise language for example in defining second order noise she uses the ambiguous phrase a formally relevant document which is not really relevant   presumably meaning not subjectively relevant according to the real need of the enquirer and in her mathematics as she admits no account is taken of the subjective relevance pertinence yet this is surely the true aim of the system
CISI	an evaluation of query expansion by the addition of clustered terms for a document retrieval system an evaluation of graph theoretical clusters of index terms which can be extracted from an automatically indexed document collection and the effects of employing such cluster in automatic document retrieval is described the graph theoretical cluster which were developed from six data base under two different cluster definition were analyzed for average size and related data the clusters were also used to expand the queries in each of six data bases to determine the effect of the expansions on the document retrieval results although a large variety of clusters and associated query explanations were obtained no significant improvements in the document retrieval performance were achieved in some cases however significant degradations in the retrieval performance occurred although seemingly meaningful clusters can be obtained the results indicate that the effort involved in finding clusters and adding the clustered terms to queries is far to great to warrant their use in an operational system the data bases employed were relatively small and the authors caution against generalizing these results to large data bases or other situations
CISI	situational relevance the concept of situational relevance is introduced based on w s coopers definitions of logical relevance on the notion of evidential relevance drawn from inductive logic on the notions of a personal stock of knowledge and a set of personal concerns the latter explained in terms of preferences over ranges of alternatives situationally relevant items of information are those that answer or logically help to answer questions of concern significant situationally relevant information is explained in terms of changes of view in relation to questions of concern it is claimed that situational relevance is an explication of the ordinary notion of practical relevance and that it is the appropriate relevance concept to use in evaluation of systems supplying practically relevant information
CISI	selection of equifrequent word fragments for information retrieval the design of programs to research large document data bases is discussed with regard to the use of compression coding combined with adoption of word fragments as the basic language elements an algorithm is described for determination of a set of almost equifrequent fragments its efficiency is tested for a sample data base formed from the marc tapes a certain threshold frequency acts as a parameter whose value determines the number of distinct fragments the selection algorithm is designed to give some preference to choice of the longest fragments and hence allow compact coding of the data base by concatenation of non overlapping fragments
CISI	interaction between requesters and a large mechanized retrieval system in a large mechanized retrieval system a certain proportion of the search failures are likely to be directly attributable to inadequate user system interaction request statements may be only distant approximations of actual information requirements this paper discusses some of the problems of the user system interface and suggests methods whereby these problems may be alleviated
CISI	the u s national library of medicine and international medlars cooperation the u s national library of medicine nlm initiated its computer based bibliographic information storage and retrieval system medlars in 1964 currently the nlm has eight international medlars quid pro quo arrangements with the united kingdom sweden france west germany japan australia canada and the world health organization the policy aspects of the arrangements are discussed as well as the organizational and operational characteristics of these non u s medlars centers
CISI	information in 1985 a forecasting study of information needs and resources the primary purpose of this study is to estimate the supply of and above all the demand for scientific and technical information its secondary objective is to make a long term assessment of qualitative and quantitative requirements for information specialists in both instances of course future technical developments as far as they can be foreseen must be taken into account at the same time like most work sponsored by the oecd its aim is to identify significant criteria for defining a policy   in this case an information policy which is greatly needed in all oecd countries
CISI	information analysis and retrieval therefore the purpose of this book remains the same as that of textbook on mechanized information retrieval   to teach basics to those who have had no previous exposure either to the field or to computers or both therefore the action is slowed to the point where the logical principles of information retrieval systems are laid bare other books have been published that emphasize computer programming   this one does not
CISI	fuzzy sets a fuzzy set is a class of objects with a continuum of grades of membership such a set is characterized by a membership characteristic function which assigns to each object a grade of membership ranging between zero and one the notions of inclusion union intersection complement relation convexity etc are extended to such sets and various properties of these notions in the context of fuzzy sets are established in particular a separation theorem for convex fuzzy sets is proved without requiring that the fuzzy sets be disjoint
CISI	information and its user in science and technology user studies are numerous and have a history of some twenty years the relevance of the methodology of science user studies to the social sciences is considered in chapter 2 the pressing need in user studies in science as well as social science is for a general body of theory about the flow of information in research and teaching communities some of the fundamental characteristics of social science research and its literature which have a bearing upon investigations of information needs and requirements are considered in the first part of chapter 3 and the second part is devoted to a review of empirical studies in the social sciences other relevant material about the use made of information is discussed in chapter 4 on systematic approaches
CISI	information mechanism and meaning in a day when it is hard enough in most fields of science to keep abreast of new and non redundant literature the publication of collected papers like the estate of holy matrimony is something not to be undertaken unadvisedly lightly or wantonly in the present case it would not have been considered at all but for the kindly initiative of my respected friend professor roman jakobson whose persistent encouragement alone overcame that distaste which most of us feel for our ten  to twenty year old productions and brought this first volume to the point of no return it is true that these exploratory papers were scattered among an unconscionably awkward selection of publications for anyone wanting to follow them up on the other hand as most of them were written for specific occasions each of which demanded some rehearsal of points covered in earlier essays the resulting repetitiveness presented a special problem with occasional exceptions redundancy could have been eliminated only at the cost of mutilating individual papers the solution adopted has been to leave almost all repetitive passages intact offsetting in small print those that can be skipped without loss by readers of the earlier chapters where some comment has seemed necessary by way of foreword or postscript to the original papers the passages added have been italicized
CISI	information retrieval systems this book is concerned primarily with those intellectual factors that significantly affect the performance of all information retrieval systems namely   indexing policy and practice   vocabulary control   searching strategies   interaction between the system and its users my viewpoint is that of the evaluator of information systems i have therefore paid considerable attention to a discussion of the requirements of users of information systems and the measurement of system performance in terms of the efficient and economical satisfaction of these requirements the book does not concern itself except indirectly with equipment for the implementation of retrieval systems a topic that is adequately covered by other volumes in this seris moreover it is my contention that the importance of hardware and data processing aspects of information systems has been exaggerated in the united states with some detriment to the performance of many systems
CISI	information retrieval on line this book deals with on line systems for bibliographic search and retrieval the literature on this subject is increasing rapidly and new systems are appearing all the time we have attempted to provide a broad survey of the characteristics capabilities and limitations of present systems our emphasis is on the design evaluation and use of on line retrieval systems primarily from the viewpoint of the planner and manager of information services it is oriented toward the intellectual aspects of information retrieval rather than the hardware or programming aspects we hope that this book may have some value for all students of library and information science
CISI	information retrieval and documentation in chemistry for several years we have thought that greater effort should be expended to create more understanding of the processes involved in information storage retrieval and dissemination too often concepts deriving from science and technology are made to seem unnecessarily abstruse either inadvertently or deliberately to preserve some sort of mystique this book is intended to explicate if not popularize major aspects of i s r processes as they are exemplified by the field of chemical documentation to the extent that this work is found useful by chemists information specialists and all individuals interested in scientific documentation we shall be gratified
CISI	information retrieval and processing the present book embodies a change in structure and focus to reflect the fact that the reader of todays book is much more likely to be an interested college student with a great awareness of the current information revolution than was the case ten years ago thus hardware materials and processes used in connection with information systems are discussed first in chapters two through four the subject of information retrieval per se begins with chapters five and six which have to do with librarianship and documentation because of their somewhat historical slant these chapters along with seven are the only ones taken from the 1963 book which adhere to their original character chapter seven presents a simplified concept of an information system and its components and paves the way for discussion of computerized retrieval in the chapters to follow especially for data retrieval in chapter eight and document retrieval in chapter nine chapters ten through twelve on language processing evaluation and user studies describe important facets of the information retrieval field that have developed strongly since 1963
CISI	information retrieval the material of this book is aimed at advanced undergraduate information or computer science students postgraduate library science students and research workers in the field of ir some of the chapters particularly chapter 6 make simple use of a little advanced mathematics however the necessary mathematical tools can be easily mastered from numerous mathematical texts that now exist and in any case references have been given where the mathematics occur
CISI	information retrieval british and american 1876 1976 of eight chapters this first one deals with principles and definitions and then with the slow development of information retrieval through about 5 000 years until the introduction of printing in europe less than 500 years prior to our period of principal coverage 1876 1976 this latter period coincides with the second century of the united states of america during which were intensified earlier efforts to carry out one of washingtons urgings in his farewell address promote then as an object of primary importance institutions for the general diffusion of knowledge
CISI	similarity relations and fuzzy orderings the notion of similarity as defined in this paper is essentially a generalization of the notion of equivalence in the same vein a fuzzy ordering is a generalization of the concept of ordering for example the relation x y is a fuzzy linear ordering in the set of real numbers more correctly a similarity relation s is a fuzzy relation which is reflexive symmetric and transitive various properties of similarity relations and fuzzy ordering are investigated and as an illustration an extended version of szpilrajns theorem is proved
CISI	using commercially available literature tapes for a current awareness service the paper reviews the need for current awareness services and describes the basic characteristics of sdi indicating its advantages details are given of the problems that have arisen in providing an sdi service based on chemical titles tapes at aldermaston with particular reference to program limitations data on operating costs and on use assessments of the service are given the pros and cons of title only alerting systems are discussed
CISI	the university of sheffield biomedical information project an outline is given of the history of the project and the development with osti support of an information service in intestinal absorption which is intended to become self supporting results of an evaluation of computer based current awareness techniques including journal scanning is discussed with reference to cost completeness and minimum delay a simple technique is suggested for profile construction e g for chemical titles computer search based on frequency and specificity of words in a sample of relevant titles
CISI	exploitation of literature on tape experience of the use of a number of commercially available magnetic tapes for a current awareness service is described difficulties encountered in the assimilation of various types of tape format into the system developed for the unilever research laboratory are discussed and problems in the retrospective searching of tapes are outlined
CISI	analysis of on line searching costs a project was undertaken to discover the major determinants of the costs of searching on line on a practical reference retrieval system scisearch the methodology and some results of this project are reported controlled searches were undertaken to isolate the effect of each of a number of variables a model involving several of the major variables was then developed the general approach proved to be in this case both feasible and useful
CISI	the phenomena of interest to information science discusses the various explicit and implicit definitions of information and information science against a view of their historical development shows how the various views of information science overlap with other disciplines and concludes with a proposal for a definition of information science based on social need a schema of information sciences is put forward with the plea that any discussion of information and information science should first declare the definitions to be used
CISI	information service in libraries the two studies presented here represent efforts to measure the performance of library staffs in an unobstrusive fashion that is to apply certain tests generally similar to portions of the normal workload without drawing attention to the fact that a test is being carried out the two projects were rather different as to purpose method and reliability of result that is statistical significance dr crowleys investigation the first in point of time arose partly from his experience in a county library his curiousity about the real result of the reference activities as different from merely counting the questions answered led him to ask is there substantial difference between the claims made by librarians for reference work and the actual result as observed in a number of different situations by individuals posing as clients the study which followed from this question was then exploratory and necessarily less rigidly controlled than was the second study of this pair
CISI	information storage and retrieval tools elements theories this textbook grew out of some discussions between the authors about the interdisciplinary character of the field of information storage and retrieval we both felt that the need existed to show what each professional group concerned with the solution of information storage and retrieval problems could contribute a university level course was developed based on the concept that each person should be made aware of how others could help him the course was presented about a dozen times over the ensuing years and this book is based on it
CISI	information storage and retrieval systems for individual researchers this book deals with the simplest of the three corrective measures   the improvement of the document retrieval system there are different ways and means of accomplishing this and these methods of improving the organization and retrieval of personal document collections are the principal topics to be covered the book is addressed primarily to the researcher in any subject field who desires to improve the index to his document collection or start an index to his document collection but does not quite know how to go about it an index is herein defined as a systematic organization of a collection of documents or data there are indexes to various types of document and data collections and there are various types of indexes examples of familiar indexes are indexes to individual books to collections of books the card catalog in a library to the contents of journals or periodicals for example the readers guide to periodical literature to collections of facts for example a telephone directory or to numeric data such as physical constants of a group of compounds or numeric data collected in a questionnaire study
CISI	bibliographic coupling extended in time ten case histories the methods of bibliographic coupling were applied to 8186 papers in thirty  five volumes of the physical review vol 77 1950 to vol 111 1958 the results are reported in the form of ten case histories each case was chosen to illustrate a problem in information retrieval
CISI	a methodology for test and evaluation of information retrieval systems a recognition of the importance of useful evaluative techniques is an indirect or secondary result of the hugely expanded national investment in scientific research such recognition has followed the expenditure of much time and money on the development of information systems which utilize advances in information handling and data processing primarily computer oriented to handle the explosion of recorded information information scientists from a typically diverse group of parent disciplines are now cooperating not only to develop methodologies of evaluation of such systems but to apply them
CISI	factors affecting the preferences of industrial personnel for information gathering methods a structured questionnaire was administered to professional personnel in industrial and government organizations asking the subjects to rank eight information gathering methods according to their preference in given hypothetical situation the subjects were then asked to rate the methods on a seven point scale according to a ease of use and b amount of information expected the subjects were divided into two groups determined by their time spent in research or research related activities the groups were designated research and nonresearch a statistical analysis of the data from 96 subjects 52 in research 44 in nonresearch showed that no statistically significant differences were present in either the rankings or ratings between research and nonresearch personnel the results of the study infer that the ease of use of an information gathering method is more important than the amount of information expected for information gathering methods in industrial and government regardless of the research orientation of the users
CISI	on the articulation of surrogates an attempt at an epistemological foundation there are two major purposes in mind for this gathering the first is the most general that can be proposed for any gathering the simple advantage of bringing together those who have been at work on a single problem or at least a small class of problems   especially when this problem has not previously benefited from exclusive and thematic collaboration among its investigators to further such thematic collaboration the formal presentations have been scheduled no more than three each day with time left after each presentation for formal discussion here in the conference room and with as much time as possible   given the number of presentations   left free for informal discussion the second purpose is one of even greater necessity in my opinion though one not so obvious as the first over and above the hope for interchange of what has already been thought out   in the form of personal contact where the presence of the originator of the system or theory can reinforce the printed word in its usual and ineffable way   it is my hope that we will all be able especially in our informal discussions to penetrate beyond mere similarity and difference to the underlying philosophical bases of syntactic relationship
CISI	some remarks on information languages their analysis and comparison the machine language information language in our terminology d s should not be confused with the machine code upenskii 59 357 in ranganathans more general terms there should be no confusion between the idea plane and the notational plane many difficulties in classification arise from this confusion this paper is devoted mainly to problems on the idea plane the ir language i want to talk about is the language in which the information to be retrieved is formulated i e a declarative sentence language not the imperative sentence language of the programmer retriever bohnert in samet 62 1 10 that is the information language should not be confused with the programming language to avoid misunderstandings it would perhaps be better to say descriptive instead of declarative and to state explicitly that in a descriptive sentence an imperative may be described which is however not to be executed by the system but to be retrieved by appropriate searches
CISI	concept organization for information retrieval all analysis of information for storage and of questions for effecting retrieval must be in terms of concepts and the relations between them the concepts may be just words descriptors as in simple post co ordinate keyword indexing systems or they may be class terms or other idea groupings as in classifications the relations between concepts often appear to be absent but if more than one word is used in indexing or in a search there is clearly an implicit relation between them in the mind of the indexer or questioner and other relations possible between the words would lead to false drops classification has traditionally been a method of organization of concepts in which the relations between concepts are ostensibly displayed in the form of groupings called classes
CISI	automatic term classifications and retrieval recent research at the cambridge language research unit has been concerned with the application of the automatic classification techniques associated with the theory of clumps to document description obtained from the aslib cranfield project and with the use of the resulting term classifications in retrieval a substantial program engine has been developed which computes similarities between pairs of terms on the basis of their occurrences and co occurrences in document descriptions and finds classes of terms with strong similarity connections by minimizing the cohesion between a potential clump and its complement and which retrieves using single terms and or term classes according to specification and calculates recall and precision ratios for sets of requests serious tests with different similarity and clump definitions and with different modes of using term classes are still in progress so on definite conclusions about the value of this kind of classification are presented
CISI	some structural characteristics of articulated subject indexes an articulated subject index is one in which logical transformations of natural language phrases containing prepositions or connectives are employed to organize the noun phrases as subject headings with subordinate displays of the remainder of the phrases the best known example of the articulated subject index is that to chemical abstracts it has been shown that a well defined transformation links the entry as it appears in the index with the original phrase in natural order as it was first compiled by the indexer a reverse transformation can be used to generate potential index entries from indexing phrases containing one or more prepositions or connectives a simple model has been devised for the generation of articulated subject index entries from natural language indexing phrases which exclude infinitives or words acting as gerunds or participles a sorting algorithm has also been developed the purpose of which is to select those entries which lead to greatest organization in the index display deviations from the model in manually produced indexes are described the potential value of certain of these characteristics in information retrieval is examined
CISI	integrated information processing and the case for a national network the various premises which need consideration when developing a realistic and flexible information storage retrieval and dissemination isrd system are discussed their implication is illustrated with some examples from the development of the system at shell research sittingbourne one of the factors which will affect the satisfactory performance of an isrd system is the ease with which relevant literature information not held in the system can be provided the later part of the paper is developed to a discussion of this problem and of a possible means of dealing with it in the not too distant future
CISI	some experiments in the selective dissemination of information in the field of plasma physics a small scale computer based sdi system in plasma physics and the related subjects is described briefly the system serves about 100 research scientists and engineers and uses title input only in order to minimize input costs the implications of this approach and its effect upon the system parameters is discussed some comparison of the costs of the computer based system with those of a manual system is made further experiments are described in which the service is expanded to external users on a world wide basis the aim being to compare under controlled conditions the parameters of the small scale internal service with those of an external service on a wide scale the paper concludes with some observations on the future development and organization of computer assisted services their possibilities and the main problems which are likely to arise
CISI	performance of automatic information systems the smart document retrieval system is used to investigate algorithms for text analysis and request searching results from three document collections indicate that word normalization is efficiently performed by automatic thesaurus lookup while phrase matching procedures statistical association methods and concept hierarchies are useful for special applications automatic document clustering schemes and use interactive feedback methods permit rapid searches of large collections abstracts are found to be superior to titles as a base for content analysis in a document retrieval system and almost as good as complete texts proper procedures for designing dictionaries and searching requests are discussed the practicality of large scale document centers and their proper design are considered in light of these results
CISI	negotiation of inquiries in an on line retrieval system the focus of discussion is a prototype retrieval system with three major components for text processing connectivity and decision operations each of these components is based on a distinguishable subtheory computer programs for the first two components have been written for a ge 225 computer the complete prototype system is now being programmed for operation in a time shared environment it is a user oriented system with planned capabilities for the browsing and man machine interaction a major goal is to develop procedures whereby research workers can conduct an on line dialog via terminals with a body of scientific information each user submitted inquiry is a set of sentences without restriction as to vocabulary or form the system converses with the user to obtain source derived phrases that elaborate and refine the initial inquiry the use is led to browse in the general area of his inquiry and to broaden or narrow it as a further aid to request formulation evaluation of system performance is described
CISI	a clustering experiment first step towards a computer generated classification scheme a document collection consisting of 240 articles on theoretical high energy physics is analyzed by an empirical clustering procedure in which bibliographic coupling obtained by computer is used to measure the relatedness of articles meaningful groups of documents were produced the clustering process ia adapted to future use in the computer generation of a classification scheme
CISI	relevance assessments and retrieval system evaluation two widely used criteria for evaluating the effectiveness of information retrieval system are respectively the recall and the precision since the determination of these measures is dependent on a distinction between documents which are relevant to a given query and documents which are not relevant to that query it has sometimes been claimed that an accurate generally valid evaluation cannot be based on recall and precision measures a study was made to determine that effect of variations in relevance assessments on the average recall and precision values used to measure retrieval effectiveness using a collection of 1200 documents in information science for test purposes it is found that large scale differences in the relevance assessments do not produce significant variations in average recall and precision it thus appears that properly computed recall and precision data may represent effectiveness indicators which are generally valid for many distinct user classes
CISI	an indirect method of information retrieval the information retrieval process treated strictly as a matching procedure has the defects that tha whole file must be probed for each query and that it overlooks the fact that the relevance of the information from one document depends upon what is already known about the subject and in term affects the relevance of other documents subsequently examined a mathematical model of a search technique in which the defects of the direct method are taken into account is demonstrated by an experiment in which a given paper is treated as an enquiry and the references cited in the paper are treated as relevant answers the results in two tests show much better results than those achieved by the direct method no spurious material was retrieved by either method
CISI	the use of automatically obtained keyword classifications for information retrieval this report summarizes the work carried out on the automatic construction of keyword classifications and their use in information retrieval that we have carried out in the last eighteen months it discusses the possible characteristics of such classifications and potential ways of using them and described the various approaches to classification we have considered in terms of an overall frame of reference in which several types of classification are distinguished the results of experiments using a collection of documents and test requests obtained from the aslib clanfield project are presented from which it can be conclude that automatic classifications which lead to noticeable improvements in retrieval performance over those obtainable with unclassified terms can be set up
CISI	experiments in book indexing by computer the most challenging task in preparing an index to a book is to select all and only those terms that are related to the text and are useful for relevance purposes while a knowledgeable human can make the selection on an intuitive basis automatic indexing requires a precise operational criterion for defining and selecting good and useful index terms two principles of selection are proposed specification and selection of useful terms and specification and exclusion of useless terms because of the nebulous nature and meaning of good index terms and the difficulties involved in devising machine algorithms for their selection this research in automatic indexing is based on the principle of excluding useless terms even so fully automatic indexing was not achieved in this study single words proved to be little value as index terms multiple word terms were generated by the computer but no algorithm could successfully eliminate the useless phrases final selection had to be made by the experimenter a comprehensive and useful book index was achieved by using machine aided rather than fully automated indexing techniques
CISI	computer use in information and data handling an appraisal of its economic aspects the economic merits of applying computers in information storage retrieval and dissemination have usually been considered with respect only to the cost of operating the information services concerned this had tended to indicate that computer use is economically justified mainly for housekeeping operations in the large scale organizations the present paper takes a wider view and included in its appraisal the costs involved in information gathering and dissemination for the total system representing the information services and its users it is suggested that the inclusion of cost elements associated with user time devoted to information gathering tends to shift the economic appraisal in favor of computer application in information work in fact such computer use appears to find its main stimulus and economic justification in an environment that provides strong incentives to minimize the total cost of the system whilst maximizing its benefits to the users to illustrate this some example are given based on experience gained in research data handling and the operation of sdi services in an industrial research establishment
CISI	the unilever research sdi system the research sdi system has now been in operation for one year using the isi source tapes as a data base tapes are received weekly from isi philadelphia and are run against approximately 20 000 search terms representing about 350 profiles the computer system and search programs will be described together with costs for the operation user reaction will be commented upon within the context of future developments of sdi
CISI	performance and cost of free text search systems the purpose of an information retrieval system is to provide the user with citations relevant to his query since the user is the only person competent to make the final judgement of relevance it is natural to suppose that the selection of items from a data base will lead to two kinds of retrieval error the extent of these errors is expressed by the familiar measures of performance precision and recall precision measures the failure of the system to retrieve only relevant documents while recall measures its failure to retrieve all relevant documents actually present in the data base it is difficult to visualize a situation in which a user would find advantage in being provided with irrelevant citations from the users point of view therefore a system which offers less than 100 per cent precision is a deficient system
CISI	experimental use of a program for computer aided subject index production stages in the development of a program for the production of articulated subject indexes are described the preparation of an index to the third edition of the smre bibliography has enabled the technique to be assessed in a practical situation titles from 1700 documents included in the bibliography were edited to provide input to the program and the output recorded on a micro film hard copy recorder in upper case alone further developments now in hand are indicated and criteria for assessing the suitability of the technique relative to other index production techniques are discussed
CISI	the design of cost effective hierarchical information systems the provision of periodicals and bibliographic aids for the three levels of the hierarchy is considered viability analysis establishes minimum operating scales and bradford zipf analysis optimizes the selection
CISI	optimum procedures for economic information retrieval computer searches on chemical titles tapes for current awareness at the university of alberta since may 1968 have provided sufficient data to allow formulation of a cost function based on the number of titles searched the length of questions the extent to which questions may be batched and certain details regarding the allowed forms of question with different choice of parameters the cost function could be adapted to apply to searches of other data bases an attempt to make retrospective searching economically feasible has led to formulation of different search techniques it is suggested that the search procedure should be designed to minimize computation time at the expense of convenience in the form of output but that facilities should be included so that the user who is willing to play the additional cost may receive output in a more convenient form in recognition of the fact that the form of search question should be dependent on the vocabulary of the data base a program has been developed to modify a question so that it is optimal for searches on the given data base
CISI	the cost and costing of information storage and retrieval this presentation on economic aspects of information retrieval is based on data gathered by project urbandoc during the course of four years in developing documentation services for the literature of urban planning and renewal it was a substantial effort   half a million dollars is no small sum in the social sciences   made possible by an urban renewal demonstration grant from the u s department of housing and urban development hud to the city university of new york the proposal that initiated the project in 1965 grew out of the extensive dissatisfaction with bibliographic services in planning librarianship at a time when both planners and librarians were looking to data processing to solve a variety of information problems urbandoc was to apply the techniques of scientific documentation to a body of literature which had been neglected by the information science community before the advent of computerization and completely by passed by it afterwards
CISI	some cost estimates for bibliographical searching in a large scale social sciences information system many of the large scale mechanized information systems in operation today grew up because of the need of the military and para military establishments to have rapid access to large quantities of scientific and technological information this paper will deal with two complementary efforts in the field of social sciences where an awareness of the information problem is acute and the global needs staggering the target audiences for these two systems are on the one hand social science researchers and on the other policy planners and makers in the broad field of economic and social development an operational system in the international labour office will be described and an array of figures representing actual or theoretical operating costs will be given as could be expected however these figures relate only to costs of systems development input preparation file maintenance and retrieval no attempt can be made to evaluate in other than general terms the economic impact that the existence of such a system may have it can be readily demonstrated however that computer assisted information systems may make sense within individual institutional environments and make greater sense when on line systems linking various collaborating institutions can result in enabling each to operate more efficiently and at lower cost the existence of such on line networks would make the greatest sense for users because of the possibility of having access at a reasonable price to large information stores
CISI	mechanized searching of acts of parliament this paper reports the results of a practical study of the application of digital computers to the storage analysis and retrieval of the full text of acts of parliament and associated delegated legislation dealing with automatic energy a total of some 140 000 words a suite of computer programs has been prepared in a high level language for generating a dictionary and concordance to the full text and organizing the search process the interrogation language quest is described and its application to full text searching discussed
CISI	experiments in automatic extracting and indexing this article reports on several experiments in automatic extracting and one experiment in automating indexing nine chapters each from a different technical book were used as a text corpus for all the experiments in the first experiment an attempt was made to construct a sentence dictionary of syntactic sentence types for distinguishing extract worthy sentences but it proved unrewarding nevertheless the results indicated that sentence typing might be used in a screening process in conjunction with other extracting techniques the later attempts to combine synactic and statistical criteria in the choice of extract sentences and index phrases proved more rewarding the sentences selected by the extracting algorithm were representative and are presented for the reader to peruse the noun phrases selected by the indexing algorithm compared favorably with the back of the book index phrases there is every indication that satisfactory back of the book indexes could be produced automatically with post editing to delete superfluous items
CISI	cost effectiveness as a guide in developing indexing rules to date the many decisions among alternatives that are required in the course of developmental efforts to improve indexing have with few exceptions been guided primarily by criteria related to effectiveness as measured by some objective method or as judged subjectively although effectiveness type criteria may be adequate for work intended solely to advance the state of the art when the goal is to develop indexing techniques appropriate for operating services it seems highly desirable to employ some criterion that takes cost as well as effectiveness into consideration the central problem of operating services can be reduced to either that of producing the best indexing possible at a given cost or that of producing indexing of a given level of effectiveness at least cost in our current effort to develop rules for human machine and man machine indexing we employ a cost effectiveness type of criterion in making the critical developmental decision the general approach is described and illustrated with examples of how measures of cost and of effectiveness were considered jointly in decision making primarily for how to reduce cost of indexing at a given level of effectiveness problems of defining cost are also discussed such as how to divide indexing into discrete steps the effects of long term vs short term activity in humans and small batch vs large batch considerations for machines
CISI	compilation of thesauri for use in computer systems a thesaurus can be defined as a structured vocabulary for use in information storage and retrieval systems three parts of this definition need further elaboration 1 a vocabulary is a collection of terms 2 the structure of a vocabulary can be described as a set of relationships between terms 3 utilization of a thesaurus in an information system involves a set of rules which take into account the characteristics of the system
CISI	information seeking behavior of catalog users this study is based on the data from a survey of catalog use at three university libraries and one public library both known item searches and subject searches were analyzed the characteristics of the user population were examined and methodological problems of the survey were discussed a relation was found between the academic rank of the catalog users and type of search that they carry out some of the factors influencing the success or failure of the search were analyzed and the meaning of success for the two types of search was discussed the study investigated tends in search strategies as well as degree of perseverance of catalog searchers implications for the design of modern information retrieval systems were pointed out
CISI	automatic classification and retrieval of documents by means of a bibliographic pattern discovery algorithm we present completely automatic procedures for the self generation of meaningful groups among the members of a document collection and for the classification according to these groups of subsequent documents these procedures operate on large document collections with reasonably short computation times thus far in our experiments on the physics literature automatic classification has proven to be as good as or better than manual indexing and in addition potentially less expensive empirically derived our method is based upon a pattern discovery algorithm which use only the citation content of a document and with operates on the bibliographic links among papers the self generated groups correspond to very specific subject headings retrospective bibliographies generated in the procedures allow one to classify the subsequent literature with remarkably high recall and relevance ratios close to 100
CISI	columbia university school of library service system for thesaurus development and maintenance a system for computer based thesaurus production and maintenance has been developed at columbia university school of library service the system is highly flexible providing for all the types of data elements which have been used in both thesauri and subject heading lists with additional features found to be useful as a result of the ongoing research program at columbia three thesauri in widely varying subject fields are in the final stages of production under the system as a result of the simultaneous development of the thesauri based on actual indexing universes and of the production system which is part of a larger program of research in information handling problems a variety of new techniques and procedures have been developed as their usefulness became evident
CISI	five years five volumes and 2345 pages of the annual review of information science and technology the annual review of information science and technology arist is now 5 years old in these 5 years arist became not only a very much used and quoted tool but also an established institution this is testified by the fact that each of the five volumes was the years most frequently and most comprehensively reviewed book in the field the arist effort is unparalleled in great many fields currently we are entering an era of intense concern about and reactions to science and technology all sciences and technologies are subject to questioning scrutiny and evaluation both inside and outside of their subject areas scrutiny of a field may be attempted by a scrutiny of its important literature items with 5 years and five volumes arist invites and affords a perspective this review is attempting in broad brushstrokes to be a critical examination of the underlying structure and literature base as well as the achievements of the arist effort as a whole
CISI	a technique for the evaluation of a commercial information service and some preliminary results from the drugdoc service of the excerpta medica foundation the selectivity timeliness and quality of indexing of a commercial service may be assessed by comparing the journal articles chosen by an organization as relevant to its interests with those subsequently reported by the service these aspects were evaluated with respect to drugdoc which scans over 3400 biomedical journals the results showed that the selection criteria laid down by drugdoc are strictly adhered to the mean time of alerting of an article was 11 3 weeks after receipt of the journal at wellcome and all articles from a particular journal issue were reported by drugdoc on average within 13 6 weeks indexing was examined in detail and on average 8 1 primary thesaurus controlled indexing terms were assigned per article pilot studies were also run on sdi profiles compiled from the drugdoc thesaurus
CISI	a multidisciplinary and computerized sdi service for industry and research practical experience and costs in this paper the experiences costs price policy market sales promotion and foreign cooperation of a danish documentation department are described in relation to two databases as follows the compendex tapes are scanned in denmark whereas the inspec tapes are scanned in holland with the inclusion of danish profiles according to a bilateral agreement the total costs in connection with compendex are evaluated and divided into four main components disbursement to the supplier of the tape system working expenses of the documentation center costs of the electronic data processing and expenses connected with the procurement of the original material to the subscribers they can choose between including or deleting the compendex abstracts during sequential text scanning and printing out search profiles are formed by the terms word author journal code connected by and or not logic and weight factors the above documentation department belongs to the national technological library of denmark and also two sdi services based on tape systems from cas retrospective searches have been carried out
CISI	interactive reference retrieval in large files we express the conviction that on line reference retrieval will largely replace the present tape driven system in a few years we describe the design criteria of such an on line system based on our experience of a pilot system which has been operational for 2 years emphasizing the importance of minimizing the number of disk accesses we recommend the use of hash coding for searching in a thesaurus and point out that the user of an on line system should use the most precise terms first and the common terms last   the opposite of the procedure in a manual search
CISI	the use of hierarchic clustering in information retrieval we introduce information retrieval strategies which are based on automatic hierarchic clustering of documents we discuss the evaluation of retrieval strategies and show using a subset of the cranfield aeronautics document collection that cluster based retrieval strategies can be devised which are as effective as linear associative retrieval strategies and much more efficient finally we outline how cluster based retrieval may be extended to large growing document collections and indicate some ways in which the effectiveness of cluster based retrieval strategies may be improved
CISI	retrieval efficiency from titles and the cost of indexing by the means of the flexible machine search system three experiments have been made in order to test the retrieval efficiency of searching free text and keywords base upon the relevance judgements of the users the results indicate that titles and abstracts are good index material which can be used for machine searching without human indexing in the three fields studies
CISI	program design for retrospective searches on large data bases retrospective search of large document data bases requires development of special techniques for automatic compression of data and minimization of the number of input output operations to the computer accessible files also the computer program should be designed to require a relatively small amount of internal memory the present paper contains a description of the structure of a program that meets the above requirements the vocabulary of the data base is automatically expressed in terms of 8 16 and 24 bit codes chosen to point to the natural spelling in a dictionary thus file size is reduced without the necessity for extensive processing for decoding use of a compressed bit string inverted index greatly reduces search time and a storage management system enables long strings to be processed with use of a limited amount of internal storage creation of reduced files and tables is an important feature of a program it allows the files needed only by specific phases of the program to be designed to use a relatively small amount of internal storage and input output time
CISI	experiences of iit research institute in operating a computerized retrieval system for searching a variety of data bases the computer search center csc at iit research institute iitri provides information from computer readable data bases to users in industry government and universities the center was designed to meet user needs by providing a variety of services from multiple data bases with minimal restrictions and a high degree of flexibility a new modular machine independent pl 1 software system was developed for handling virtually any bibliographic type base csc have run at nine different computer facilities with different hardware computer models versions of os peripherals of the pl 1 compiler all data bases are converted by preprocessors to a standard iitri format which employs a directory and character string type of the structure user oriented profile features include full free form boolean logic with any degree of nesting search terms may be any data element on a data base search terms may be single words multi word terms phrases or term fragments full truncation capabilities optional sort of author citation number or weight and optional printing of output on 5x8 cards multilith masters paper or tape user aids were developed for each data base to assist in profile and monitoring they include search manuals truncation guides term frequency list and klic indexes research is conducted and statistics maintained to study monitor and improve center components including data bases user satisfaction systems personnel functions and services the many advantages of computerized retrieval which are the raison detre for the center include coverage thoroughness consistency interdisciplinariness recall speed regularity file preparation and cost effectiveness
CISI	communication and information processing within scientific disciplines empirical findings for psychology scientific disciplines can be regarded as social devices which have as one function the analysis and reduction of raw information to assimilated knowledge of a type which can be transmitted through professional training data on information flow in psychology reveal feedback to scientific workers and result in refinements of the product of research later disseminations are interwoven with processes of evaluation and selection and are directed toward the creation of an integrated and tested body of knowledge the reported data finish an empirical base for zimans consensual model of science and illuminate difficulties which have arisen in the design and implementation of information systems
CISI	evaluating the effectiveness of an on line natural language retrieval system an evaluation of an on line retrieval system known as ears epilepsy abstracts retrieval system has been performed the system which permits the free text searching of approximately 8000 abstracts drawn from epilepsy abstracts is supported by the national institute of neurological diseases and stroke ninds specialists in the field of neurology at six medical centers in the united states conducted on line searches to satisfy their own needs for information parallel searches were conducted on the same search topics by a neurologist at ninds who was highly experienced in using the system the results of the original searches were evaluated in terms of recall precision and general user satisfaction a detailed analysis of factors affecting the success and failure of the on line searches was carried out
CISI	a journal selection model and its implications for a library system the problem of selecting which journals to acquire in order to best satisfy library objectives is modeled as a zero one linear programming problem and examined in detail the model incorporates an objective function based on expected usage as a measure of journal worth and cost constraints which account for the scarcity of capital the model can be used to aid the librarian in making better selection decisions since the objective function can be shown to reflect the evaluation of the library as an information retrieval system and as a service organization moreover the model of seen to be related to inventory problems and scheduling models in industrial operations journal usage is discussed as a measure of journal worth and is contrasted to journal productivity constraints are considered for scarce resources other than capital and for journal interrelationships
CISI	problems in information retrieval logical jumps in the expression of information in a structured data base such as that obtained when information is indexed in a format including explicit relations retrieval of all relevant items in response to a question may in some cases be restricted by technicalities of the structure condensations in the form of logical jumps or the omission of a concept with one relation out of a string of three concepts with two interstitial relations have been investigated by two different methods in order to overcome one of these technicalities thirty two rules are proposed which could permit the automatic condensation of either of both the stored information and the question when the concepts and relations are in the form of linear or string display nine rules are proposed for condensation of angular structures other type of logical jump and abbreviation are discussed together with related studies of expansions and inference steps
CISI	machine aided indexing of technical literature to index successfully in the defense documentation centers environment an automated system must chose single words or phrases dependent upon context rapidly and economically the automation of ddcs indexing has been machine aided from its inception a machine aided indexing mai system is described that indexes one million words of text per hour of cpu time grammatical errors do not exceed five per cent of the output so human screening is satisfactorily low the system could potentially scale up to an operational size of 10 million words of text per year   the equivalent of a dozen bibles or a third of the encyclopedia britannica in a batch mode the programs to accomplish this indexing would require no more than fifteen minutes of cpu time per week
CISI	a bayesian approach to interactive retrieval this paper presents a probabilistic model for interactive retrieval specifically it applies the principles of bayesian statistical decision theory 1 the use of both prior subjective and sample information about the relationship of document descriptions to query relevance and 2 maximization of the expected value of a utility function to the problem of optimally restructuring a search strategy in an interactive environment
CISI	distance between sets as an objective measure of retrieval effectiveness a general measure of retrieval effectiveness having full metric properties and treating the retrieval system   arbiter of relevance situation symmetrically is the marczewski steinhaus metric d measuring the distance between the set of relevant documents a and set of retrieved documents b according to d 1   n a b n a u b d can be expressed as a function of presicion and recall or of generality fallout and recall and of other sets of traditional measures acceptance of the measure allows criteria for retrieval optimality and degeneracy to be stated defined by minimum and constant values of d respectively precision recall degeneracy curves for d are given and compared with those for another general measure the probability that a document will be correctly identified by a retrieval system statistical extensions of d are examined and these and other properties of the metric are illustrated with seven examples
CISI	ca condensates as a retrospective search tool a commentary a retrospective test search on 1 year of ca condensates was carried out in order to calculate the cost per profile and to get an impression of how ca condensates would suffice as a database for a retrospective use some means of improving the search strategy by means of the cas standard distribution format were investigated the question is raised whether the costs and efforts presently devoted to research regarding retrospective searches on large free text databases are justified in view of the low average precision ratios generally observed for free text databases and the very high number of references of potential interest retrieved
CISI	compression of bibliographic files using an adaptation of run length coding substantial degrees of compression of bibliographical data bases result from the application to them a modified form of run length coding the method involves attenuation of the zero one bit ratio of the data base this can be achieved by substitution of codes with the highest zero one ratios the most frequent symbols or by substitution of 2 bytes codes for diagrams a form of run length coding in which the run length is represented as a fixed length binary number is then applied
CISI	automatic indexing and generation of classification systems by algorithm a system of automatic indexing based on bayes theorem is described briefly in assigning 124 documents to 9 categories there were 97 cases of agreement with professional indexers using a collection factor based on 87 per cent human consistency from other courses the computer appears then to index with 90 per cent accuracy in this case the technique is then used with two randomized sample document groups drawn from nine categories each group in turn is used as the basis for indexing the other the computer knows only the number of categories after 8 cycles the computer is found to have formed 9 groups consisting of about 50 per cent of documents that were also lumped together by professional indexers on the basis of subject content a new measure of performance is proposed and some other applications of the technique indicated
CISI	the cost performance of an on line free text bibliographic retrieval system the cost performance evaluation of the supars system is reported supars was an on line free text bibliographic retrieval system cost effectiveness data of such systems are not readily available in our evaluation two measures of cost were employed a computer processing charge expressed in dollars and the number of documents retrieved a measure of work that must be expended to review the retrieved items the measure of performance was an estimate of the recall ratio to obtain the requisite measures an experimental plan was developed in which experts searched the data base of psychological abstracts forming their queries from written statements of information needs these statements along with the list of documents relevant to them were produced by people with information problems tallies were kept of the number of documents retrieved before each of the designed relevant items were found the major findings are noted below 1 queries to the system employing simple boolean operators and or have better cost performance characteristics than queries using more elegant searching operators 2 on demand access to the index or dictionary contributes sizeably to improving the cost performance of the system 3 the argument is raised that human factors such as the differences among users of a system probably should be a major factor in the design operation and evaluation of retrieval systems it appears that consideration of these factors will improve system cost performance
CISI	analysis of the microstructure of titles in the inspec data base a high degree of constancy has been found to exist in the microstructure of titles of samples of the inspec data base taken over 3 year period character and diagram frequencies are shown to be relatively stable while variable length character string characterizing samples separated by 3 years in time show close similarities
CISI	on the role of subjectivity in establishing using operating and evaluating information retrieval systems treatise ii on retrieval system theory the personal literature search of a scientist is strongly governed by subjective influences if he delegates his literature search he should always be aware of the problems necessarily emanating from his subjective view this prevents him from imposing unsatisfiable demands on the delegated search particularly with respect to its expected performance and makes him conscious of the fact that in order to satisfy his entire information need he cannot dispense with the browsing serendipity of his personal literature search he will also better understand the peculiarities of the documentary methods needed for operating large and continuously growing systems as compared with the methods sufficient for his personal file the information scientist on the other hand in charge of establishing operating and evaluating retrieval systems of high performance and survival power should take into consideration the pronouncedly subjective character of fundamental notions such as information and order this gives him a better understanding of the kind of inquiries submitted to him and of the inherently even if latently subjective character of several fundamental operations in storage and retrieval and will cause him to refrain from futile attempts to make such operations more objective and formal such a better mutual understanding will be bound to promote advance in methodology and psychology of scientific communication
CISI	on line information retrieval as a scientists tool the use of an on line information retrieval system by the scientists themselves is described medusa was designed to allow physicians to interrogate the medlars data base a brief description is given of the system and details of an experiment to test its effectiveness search formulation prepared on line by medical research workers are compared for recall and precision with the same requests formulated by search editors in the normal way the results show that physicians can use an on line system effectively
CISI	a technique for machine aided indexing subject indexing of text can in principle be accomplished in many ways the technique for machine aided indexing mai developed at the defense documentation center ddc is illustrated on a randomly chosen abstract additional text is provided in coded form so that the reader can more fully explore this technique and form his own opinion of the applicability and versatility of this particular procedure the ddc method for subject indexing is very close to operational status for a data base which grows at the rate of two million words of text per year
CISI	customized user services via interactions with leadermart leadermart is a fully operational information retrieval system featuring on line interactive service to a wide variety of user groups in business industry government and universities with the availability of many computer readable bibliographic data bases experience with users dictated the development of special purpose information products based on a thorough understanding of individual client needs and the delivery of such products in a customized form each different application required a different package with variations of both software and data base coverage these packages were developed via suitable modification of modular system software to result in products tailored to user idiosyncracies the paper describes problems associated with these repackaging procedures and discusses the changes brought about by the introduction of an on line interactive retrieval service into the operating environment of users implications for networking and resource sharing focusing upon cost effectiveness and performance measures are also discussed
CISI	a remote terminal retrospective search facility using a hybrid of microform and computer storage this paper describes a technical document center providing remote terminal retrospective search capability and shows its evolution from the traditional catalog card operation the system uses mini computers for on line input and editing of data and for production of announcements and uses a commercial computer utility communication network for retrospective searching a hybrid of microform and computer storage was designed to decrease computer and line charges and to allow for security considerations bilingual search capability in either of two models suitable for experienced users or novices is provided to a network of satellite libraries separated by as much as 3000 miles a selective dissemination of information service is provided using in house and foreign data bases and serving over 600 profiles of interest
CISI	indexing language structure for automated retrieval a proposal for a computer aided method of building up an indexing language is made the method involves linking the terms relevant to any special retrieval system into the udc preferably in the form of the standard reference code when it becomes available links between the terms are intended to be established in such a way that provided indexing input sessions are accomplished via a video terminal a hybrid thesaurus classification could be built up by a form of learning process in the course of regular indexing the proposed means of establishing links between terms are described the associated computer system is outlined and an example of indexing language built up procedure is presented possible uses for natural language search using the thesaurus classification as a switching language and for automatic classification are suggested as long term aims
CISI	index term weighting various approaches to index term weighting have been investigated in particular claims have been made for the value of statistically based indexing in automatic retrieval systems the paper discusses the logic of different types of weighting and describes experiments testing weighting schemes of these types the result show that one type of weighting leads to material performance improvements in quite different collection environments
CISI	relevance pertinence and information system development the different between pertinence and relevance is discussed other pairs of terms and the differences between their members are examined and the suggestion is made that such studies could increase our understanding of the theory of information systems and hence lead to practical improvements some examples are considered among them the use of personality profiles to improve the pertinence effectiveness of systems
CISI	the dynamic scientific information user in this article we examine the concept of the information user and attempt to describe some of the dynamics of the situation by discussing some of our data relative to intraindividual variations changes which occur within individual scientists as their scientific work progresses and interindividual variations physical vs social scientists basic vs applied scientists experienced vs inexperienced scientists and scientists working in the same subject matter area vs scientists who recently changed their areas all of these were found to produce significant variation in the information needs of scientists and in the sources they used to satisfy these needs some implications of these findings relative to information technology are discussed
CISI	project intrex a general review a comprehensive review of the experimental information storage and retrieval system developed by project intrex is presented together with a description of major results and conclusions that were derived through use of the system salient features of the intrex system included an argumented catalog stored in an online interactive computer in combination with full text storage on microfiche guaranteed access to full text at remote allocations was provided through use of an automatic fiche storage and retrieval system that was computer controlled discussed in the paper are the details of the catalog structure user experiments economic studies and information system networking
CISI	information systems services and centers this book is concerned with the practices of information transfer and use it examines information science for the purpose of control of the information flood through systems services and centers the book is designed as a text for use at the university level and as a reference source for working information scientists and specialists for documentalists for engineers and for researchers in the physical life and social sciences
CISI	information theory and reliable communication this book is designed primarily for use as a first year graduate text in information theory suitable for both engineers and mathematicians it is assumed that the reader has some understanding of freshman calculus and elementary probability and in the later chapters some introductory random process theory unfortunately there is one more requirement that is harder to meet the reader must have a reasonable level of mathematical maturity and capability for abstract thought the major results of the theory are quite subtle and abstract and must sometimes be arrived at by what appears to be rather devious routes fortunately recent simplifications in the theory have made the major results more accessible than in the past
CISI	the information sciences this book describes the results of a study which the author has carried out during the summer of 1969 in heidelberg and san francisco about the development of the information sciences in the federal republic of germany this study was conducted following an undertaking between the federal ministry for scientific research the institute for documentation questions and the study group for research in system science
CISI	information retrieval systems this book is concerned primarily with those intellectual factors that significantly affect the performance of all information retrieval systems namely   indexing policy and practice   vocabulary control   searching control   interaction between the system and its users my viewpoint is that of the evaluator of information systems i have therefore paid considerable attention to a discussion of the requirements of users of information systems and the measurement of system performance in terms of the efficient and economical satisfaction of these requirements the book does not concern itself except indirectly with equipment for the implementation of retrieval systems a topic that is adequately covered by other volumes in this series moreover it is my contention that the importance of hardware and data processing aspects of information systems has been exaggerated in the united states with some detriment to the performance of many systems
CISI	information retrieval languages this book gives classification and detailed description of different types of information retrieval languages a universal scheme served as the basis for classifying information retrieval languages the book analyses in detail universal scheme similarities and differences between natural and information retrieval languages some ways of constructing information retrieval language are discussed
CISI	information methodology this book sheds light on basic problems principles and results of philosophical methodological research in information concepts gives critical analysis of its idealistic interpretation author proves possibility more general definition of information using categories of reflectivity and inequality both mathematical variants statistical probability and nonstatistical as well as semantic concepts of information are analyzed basic information species and functions in human society are determined
CISI	isbd s and title main entry for serials at the ifla liverpool conference in 1971 a joint working group of the committees on cataloguing and on serial publications was set up to draw up an international standard bibliographic description for serials taking the isbd m as a model in so far as practicable as might be expected the special problems presented by serial publications made the task of developing an isbd s a difficult assignment which the joint working group tackled with great energy and devotion the successive drafts were prepared by the chairman and the secretary mlle m  l bossuat and mlle m pelletier probably no data element presented such a severe problem as that of serial title the seemingly countless mitteilungen memoires proceedings bulletins trudys and the like seemed to demand some useful and standardized way to be identified a solution to this problem was found in the adoption of a device which consisted of marrying the author statement to the generic title proper with a wedding ring consisting of a space hyphen  space and dubbing the happy couple the distinctive title
CISI	towards a theory of the concept a concept is regarded as the common element of both classification systems and thesauri reality and knowledge are not represented by words or terms but by the meanings behind these tokens a concept of say an object a property of an object a process etc is derived from verbal statements on these as subjects and may therefore be defined as the whole of true and possible predicates that can be collected on a given subject it is from these predicates that the characteristics of the corresponding concepts can be derived common characteristics in different concepts lead to relations between concepts which relations in turn are factors for the formation of concept systems different kinds of relationships as well as different kinds of concepts are distinguished it is pointed out that an orderly supply of the elements for propositions information statements on new knowledge requires the construction and availability of such concept systems
CISI	impact of scientific serials on the advancement of medical knowledge an objective method of analysis a common tool for the selection of serial publications for a research library is the lists of most cited serials the possibilities of this method were first studied by gross and gross who in 1927 applied a method of sample statistical investigation to the grading of scientific serials according to their relative importance based on citation counting from source journals
CISI	the nature of scientific communication and influence as the formal communication system of science has become less able to supply information with the rapidity that scientists require increasing attention has been paid to the structure of communication in science how are scientific publications utilized by scientists what is accomplished by the circulation of scientific information on an informal basis how does the social organization among scientists facilitate or inhibit these processes three types of studies have been conducted in this area a studies of the scientific literature itself b studies of how scientists obtain the information which they need for their research and c studies of the relationship between scientists who conduct research in the same areas for the most part studies of formal communication and information gathering have been conducted in the absence of all but the most rudimentary theoretical models as has been pointed out in at least three recent reviews of these studies libbey and zaltman 1967 p 64 paisley 1968 storer 1968 p 12 the lack of theory can be attributed partly to the practical orientation of many of the studies and also to the fact that an adequate model cannot be based on any one of these types of studies alone a useful theory must integrate knowledge from all three types in this article we will review these studies and will describe a teoretical model which has been designed to fill this purpose
CISI	the literature of the social sciences a survey of citation studies the great concern with scientific communication in the last few decades has produced a number of studies analyzing the use of information one approach to these matters has been via the citation study   a method often used in the physical sciences but applied less frequently in the humanities and social sciences however in the latter area enough citation studies have been completed to produce material for interesting comparisons
CISI	interactive bibliographic search the user computer interface on the 14th and 15th of january 1971 a workshop on the user interface for interactive search of bibliographic data bases was held at rickys hyatt house in palo alto california the workshop sponsored by the information systems committee of the american federation of information processing societies brought together a group of information scientists who have been directly involved with this subject area they were provided in advance with a challenge paper and with a number of papers prepared in response to that challenge the workshop sessions themselves were devoted exclusively to focussed discussions of the material and of the problems in and the prospects for more effective systems design of the user interface the content of these two days of deliberation prompted making the substance of the workshop experience available to a larger audience this book is intended to accomplish that goal
CISI	aim twx   an experimental on line bibliographic retrieval system the lister hill national center for biomedical communications of the national library of medicine in conjunction with the nlm library operations staff initiated in june 1970 a new experimental service called aim twx abridged index medicus twx to provide rapid responsive searching of the medical literature this experiment is being conducted to identify the need for and usefulness of such services to help medical practitioners situated in isolated areas to assist in undergraduate graduate and continuing medical education and to provide information precisely when and where it is needed for health care a limited group of practitioners students and librarians is being given access to the system so that it will not be overloaded and rejected because of busy signals and so that a variety of user groups can test it
CISI	the computer library interface the last five years university printing presses exist and are subsidized by the government for the purpose of producing books which no one can read and they are true to their high calling books are the sources of material for lectures they should be kept from the young for to read books and remember what you read well enough to reproduce it is called cramming and this is destructive of all true education the best way to protect the young from books is first to make them in such a way that no one can find them without several years training a lecturer is a sound scholar who is chosen to teach on the ground that he was once able to learn eloquence is not permissible in a lecture it is a privilege reserved by stature for the public orator
CISI	the intergroup conflict in one broad category of theories the problems are expressed in terms of actualities of events in group relations as they exist in everyday life on the whole theories advanced by many social scientists fall in this broad category in this concern over actualities the problem is frequently not stated and discussion not developed in a way that can be tested rigorously in the second broad category of theories problems are stated and analysis carried out in terms of more rigorous appearing concepts and units of analysis theories coming from psychologists and social scientists heavily influenced by them fall within this broad category in this line of approach theories are advanced without due regard to actualities and consequently they are plagued with serious questions of validity
CISI	interlibrary loan involving academic libraries interlibrary loan transactions involving academic libraries in the united states numbered over 800 000 items in 1963 64 this number is growing exponentially large libraries report that they cannot fill about a third of the interlibrary loan requests they receive unfilled interlibrary loans are costly to both the borrowing and the lending libraries and reduce the usefulness of the service to the reader many of these interlibrary loan failures are preventable chiefly by publishing policies of the lending libraries to prevent borrowers from requesting noncirculating materials and by determining in advance what library owns the item wanted
CISI	interlibrary loan policies directory in 1972 73 approximately 194 000 interlibrary loan requests were not filled because the borrowing library in ignorance requested non circulating material contrary to the interlibrary lending policies of the lending library these unfilled requests probably cost the borrowing and lending libraries over 400 000 in wasted manpower besides disappointing readers who waited in vain for their materials much of this waste could be prevented if borrowing libraries check in advance the lending policies before sending requests the major elements determining whether or not libraries receive requests to borrow from libraries at a distance are whether the library lists unusual materials in union lists especially the national union catalog the union list of serials and new serial titles and whether it has strong collections in a subject field listed in library directories volume of out of state lending is related to the type of lending library the size of collection budget for current acquisitions number of periodicals received photocopy charges population density in neighboring states proximity to other libraries and completeness of reporting holdings in the national union catalog or other bibliographic centers
CISI	interlibrary requests our survey in other words is offered within the bounds of descriptive or deductive statistics which seeks to analyze a group not attempt to estimate the parameters of that population of which the group has been chosen as a sample the latter role is assumed by inductive statistics which makes use of probability sampling accordingly our data are presented in those forms and with those statistical measures appropriate to the methods of descriptive statistics arrays frequency distributions breakdowns by categories which seem of optimum value to the librarian and administrator e g the frequency of requests for journals versus monographs the age of journals requested the types and ages of materials requested by the various types of libraries university pharmaceutical etc the tables are arranged to give evidence of the types of frequency distribution revealed by the survey as well as to indicate central tendency dispersion rank order and possibly correlations for significant factors
CISI	an introduction to computers in information science this book is an introduction to the field of information science and technology with particular emphasis on document organization its point of view is general in the sense that it attempts to deal with types of problems rather than particular systems when particular systems are described they are used as examples of systems rather than as models the method of presentation is expository at the introductory level while differing points of view are frequently noted this book is not intended to provide definitive critical evaluation relevant research is reviewed in order to indicate current thinking and activities in the field
CISI	introduction to information science the main emphasis of this book is on work of a theoretical and experimental nature rather than on practical applications however the articles selected are viewed as having a considerable potential in two major respects they have important implications for the practice of information handling but even more important they contain aspects of generalization the book is oriented toward basic and experimental work such as that performed by traditional sciences with the hope that a reader may find much relevant to his own interests educational level and background a bridge toward generalizations a feeling of interconnection between seemingly unrelated works either presented in the book or found in the literature an awareness of apparent gaps in knowledge and even ideas for practical solutions or further theoretical or experimental work
CISI	introduction to library science basic elements of library service librarianship classifies as a social science because the library as an institution is a creature of society and its goal is the improvement of society by helping the individual to understand himself and the world of which he is a part but the library is also concerned with man as a rational being thus it remains primarily a humanistic enterprise the traditional lines of demarcation among the disciplines are breaking down and in certain areas becoming almost obliterated and librarianship in both its technology and its services is drawing ever closer to the social and physical sciences but we would do well to remind ourselves of the librarys humanistic origins otherwise in excessive enthusiasm for the technology of science and the social action of the behaviorist we may lose sight of the individual and his needs and the humanistic values implicit in them
CISI	introduction to subject indexing a programmed text this programmed text has been developed from work initially carried out under a research project funded by the office for scientific and technical information now the british library research and development department the project designed to investigate the applicability of the techniques of programmed instruction in the teaching of practical subject indexing was conducted at the school of librarianship the polytechnic of north london in cooperation with the college of librarianship wales the programmed instruction course written during this project and used by students at both schools of librarianship forms the basis of the programmed text most of the existing programmed texts relevant to the field of practical subject indexing are concerned with the translation stage of indexing and aim to impart skills in the use of particular indexing languages our intention in the above mentioned project was to produce a course of programmed instruction which presented an integrated view of the basic principles and practices of subject indexing rather than attempting to impart to the student a high degree of familiarity with any particular system
CISI	introduction to systems philosophy the general systems theory pioneered by von bertalanffy kenneth boulding anatol rapoport and their collaborators gives us a theoretical instrument for assuring the mutual relevance of scientific information and philosophic meaning extended into a general systems philosophy this instrument can polarize the contemporary theoretical scene as a magnet polarizes a field of charged particles by ordering the formerly random segments into a meaningful pattern if made good use of this instrument could channel to us a stream of informed as well as sophisticated answers through the cross fertilization of contemporary science and philosophy this then is my credo the conviction which led to the formulation of the present introduction to systems philosophy over a period of three years of research in alternating states of euphoria and dejection
CISI	introduction to theoretical linguistics this is a introductory book in the sense that it does not presuppose any previous training in the subject but it does assume that the reader   especially the reader whose educational background like my own is more in the humanities than in mathematics and science   is prepared to make a certain intellectual effort with respect to the use of symbols and formulae few subjects suffer more than linguistics from the separation of the sciences and the humanities that is still maintained in the curricula of most of our schools ad universities for contemporary linguistic theory draws simultaneously and in roughly equal measure upon the more traditional approach to language that is characteristic of the humanities and the more scientific approach that has developed recently in connection with advances that have been made in formal logic computer science and automata theory
CISI	introduction to university library administration the last ten years have witnessed the growth of an intense public interest in university affairs almost anything to do with universities is now headline news previously such attention as they did receive was limited to brief reports in sober middle class newspapers of appointments awards and meetings leavened once a year by an obligatory account in all newspapers of the boat race all this has changed as michael befoff comments in his book the plateglass universities having made the foregoing points and more besides what were once ivory towers have now become goldfish bowls he goes on to give the obvious explanation for the change universities are of public interest because they are now almost wholly supported by the taxpayers money they represent a massive investment on the part of the government and consequently are expected to yield a vitally important return in trained and educated manpower over the last twenty years government expenditure in this country on universities has risen from four million pounds a year to more than two hundred million pounds a year the total university student population is in excess of two hundred thousand and teaching and research staff number approximately twenty five thousand
CISI	indivisible colleges diffusion of knowledge in scientific communities in the last two decades dramatic increases in the scope and volume of scientific research have occurred as may be illustrated by the fact that the amount of scientific literature is doubling approximately every ten years price 1963 for the scientist who needs to locate particular items of scientific information and for the documentation specialist who must make them readily available the organization and management of this huge and expanding store of information is a serious problem increasingly radical solutions are being proposed for example some experts would like to scrap scientific journals and distribute their contents piecemeal information retrieval and delivery systems are being developed to enable scientists to locate information quickly and effectively
CISI	a dynamic programming approach to r and d budgeting and project selection contemporary models of research and development are incomplete in that they ignore the many reappraisals and budgeting decisions that occur in the time between a projects proposal and its commercialization the sequential decision aspects of project budgeting are particularly important since 1 the research expenditure is usually an order of magnitude less than the irrevocable investment for commercialization and 2 an allocation to a project today does not presuppose continuation of the project into future periods the research and development budgeting problem is structured to take into account the sequential decision characteristic utilizing the technique of dynamic programming methods are developed to determine optimal project budgets when the aggregate research and development budget is either constrained or unconstrained these models also suggest a rational explanation of the patterns of project expenditures over time that one observes in practice finally some of the shortcomings of the developed methods which inhibit their practical application are discussed
CISI	the association factor in information retrieval this paper describes an all computer document retrieval system which can find documents related to a request even though they may not be indexed by the exact terms of the request and can present these documents in the order of their relevance to the request the key to this ability lies in the application of a statistical formula by which the computer calculates the degree of association between pairs of index terms with proper manipulation of these associations entirely within the machine a vocabulary of synonyms near synonyms and other words closely related to any given term or group of terms is derived such a vocabulary related to a group of request terms is believed to be a much more powerful tool for selecting documents from a collection than has been available heretofore by noting the number of matching terms between this extended list of request terms and the terms used to index a document and with due regard for their degree of association documents are selected by the computer and arranged in the order of their relevance to the request
CISI	a study of methods for systematically abbreviating english words and names this study investigated various techniques for systematically abbreviating english words and names most of the attention was given to the techniques which could be mechanized with a digital device such as a general purpose digital computer particular was paid to techniques that could process incoming information without prior knowledge of its existence i e no table lookups thirteen basic techniques and their modifications are described in addition most of the techniques were tested on a sample of several thousand subject words and several thousand proper names in order to provide a quantitative measure of comparison
CISI	automatic document classification starting with a collection of 405 document abstracts dealing with computers the experiment in automatic document classification proceeds to construct an empirically based mathematically derived classification system by use of a factor analysis technique the documents are then classified into these derived categories by five subjects and the resulting classification serves as a criterion against which the automatic classification is to be evaluated of the 90 documents in the validation group which contained two or more clue words and which therefore could be automatically classified 44 documents or 48 9 per cent were placed into their correct categories by use of a computer formula these results are almost identical to the results obtained by maron in a previous experiment using the same data but with a different set of classification categories and a different computational formula the experimental evidence support the conclusion that automatic document classification is possible additional experiments are described which when executed should improve the accuracy of the automatic classification technique
CISI	computer evaluation of indexing and text processing automatic indexing methods are evaluated and design criteria for modern information system are derived information retrieval indexing methods automatic retrieval information systems document retrieval text analysis document handling retrieval effectiveness smart precision recall
CISI	semantic clustering of index terms a computer procedure to recognize indexing vocabularies is described index terms are drawn from the vocabulary of a structured indexing system and may consist of single words collection of words or syntactic phrases the basic idea is that a measure of the semantic association between index terms can be determined from the structural relationships which the terms exhibit by their relative positions in the system the association measure which is based on a priori preassigned semantic relationships between terms rather than their co occurrence in a document corpus is then for grouping index terms into clusters or concepts some results of an experimental investigation are presented information retrieval clustering index terms semantic graphs clusters associations synonyms subgraphs complete maximal connected component relevance measure vocabulary indexing systems cliques
CISI	the influence of data characteristics and usage on direct access file organization memory utilization and retrieval time from direct access inverted files are investigated as a function of the data base the demands on it and a parameter which the system designer may control an analysis of the effects of data base characteristics and data base usage is also made for a linked list structure information retrieval direct access memory disk drum data base access time inverted list threaded list
CISI	the application of pattern recognition to screening prospective anticancer drugs pattern recognition has been introduced to the chemical literature as a general tool which can be used by the chemist to reduce masses of experimental data to relevant information perhaps more importantly it provides connections between raw multivariant data and sought for information without making restrictive assumptions about the underlying statistics of the data the general problem has been stated as follows given a collection of objects and a list of measurements made on each object is it possible to find and or predict a property of the objects that is not directly measurable but is known to be related to the measurements via some unknown relationship the only assumption made is that similarities and dissimilarities among objects are reflected in at least some of the measurements
CISI	stereochemically unique naming algorithm an algorithm has been developed and implemented to generate for each chemical structure a unique and invariant linear name which includes double bond and asymmetric carbon isomerism a logical proof is given for the one to one correspondence between name and structure by inspection of the linear names of two structures one can determine if the two structures are identical nonisometric constitutionally isometric diastereometric or enantiometric the algorithm determines the true stereocenters and calculates a reduced set of chiral centers src it is proven that if three are any centers in src that the compound must be chiral an a chiral compound must have src null extensions of the algorithm are outlined to allow uniquely naming conformational isomers
CISI	deriving term relations for a corpus by graph theoretical clusters we discuss how alternative methods of automatic term clustering may provide insight into how terms are related within a corpus the work reported uses a corpus of 2267 documents that contain 3950 index terms a similarity matrix is developed using the document   term matrix a threshold level t is applied to the similarity matrix entries in the matrix that are greater than or equal to the threshold level are set equal to one and the remaining entries are set to zero three definitions are applied to the corresponding graph of each threshold matrix to develop clusters these are 1 the connected components of the graph 2 the maximal complete subgraphs of the graph and 3 the combined maximal complete subgraphs of the graph as described that show how insight may be gained into the term relations by varying the threshold levels and the cluster definitions
CISI	automatic abstracting and indexing ii production of indicative abstracts by application of contextual inference and syntactic coherence criteria together with the increasing shortage of qualified abstracts the factors of time cost and value have lent impetus to a trend toward the automatic generation of abstracts and indexes this trend has caused increased emphasis to be placed on the abstract as the locus of data for automatic retrieval systems this necessitates the creating of high quality abstracts it is the purpose of this paper to report on the development of techniques for the automatic production of high quality abstracts from the full text of the original document it is necessary to analyze the conditions under which various methods of sentence selection are successful in order to develop criteria for selecting sentences to form an abstract but clearly an abstract can be produced by rejecting sentences of the original which are irrelevant to the abstract as will be seen it is this point which is perhaps the most significant contribution of this paper methods of sentence selection and rejection are discussed these include contextual inference intersentence reference frequency criteria and coherency considerations the automatic abstracting system we have developed consists basically of a dictionary called the word control list and of a set of rules for implementing certain functions specified for each wcl entry the abstracts we have obtained so far are of sufficiently good quality to indicate that large scale testing of the methods of the automatic abstracting system is warranted
CISI	linguistics and information science this paper defines the relationship between linguistics and information science in terms of a common interest in natural language the notion of automated processing of natural language   i e machine simulation of the language processing activities of a human   provides novel possibilities for interaction between linguists who have a theoretical interest in such activities and information scientists who have more practical goals e g simulating the language processing activities of an indexer with a machine the concept of a natural language information system is introduced as a framework for reviewing automated language processing effort by computational linguists and information scientists in terms of this framework the former have concentrated on automating the operations of the component for content analysis and representation while the latter have emphasized the data management component the complementary nature of these developments allows the postulation of an integrated approach to automated language processing this approach which is outlined in the final sections of the paper incorporates current notions in linguistic theory and information science as well as design features of recent computational linguistic models
CISI	ascertaining activities in a subject area through bibliometric analysis a combination of quantitative and qualitative analyses were used on the journal articles indexed in one volume of library literature findings include the dispersion of a articles among journals followed a bradford type distribution except for a collapse at the end possibly showing low level of interaction of librarianship with other fields considerable proportion of articles was of news type administration was the largest single subject covered the methodology may be appropriate for analysis of activities in other fields
CISI	information concepts and their utility the concept of information is examined within the framework of the mathematical theory of communication and semiotics the study of signs and sign systems the implications of these theories for the better understanding of information as we deal with this concept in the context of information systems are discussed
CISI	a decision theory view of the information retrieval situation an operations research approach a decision theory approach is used to model the information retrieval decision problem of which documents to retrieve from a library collection in response to a specific user query for information a thorough discussion of decision theory including the components of the alternatives states of nature outcomes and evaluations   as well as of the optimization process under the cases of certainty risk and uncertainty   is presented bayesian statistics are also discussed to show how prior information about the various documents via classification analysis can affect the decision process under risk an example problem is used to illustrate the decision theory approach and to compare tha overall performance of the retrieval system under risk with and without document classification information thus the operations research technique of decision theory is used to model the retrieval decision process illustrate how important evaluation is and to demonstrate the value of prior information via document classification analysis moreover the paper presents in a somewhat tutorial mode an overall framework for considering the information retrieval decision problem incorporating the aspects of cost effectiveness and alternative evaluation which allows one to better understand the contributions made by many researchers in this crucial area
CISI	classification of scientific documents by means of self generated groups employing free language a study was undertaken to classify mechanically a document collection using the free language words in the titles and abstracts of a corpus of 261 physics research papers using a clustering algorithm results were obtained which closely duplicated the clusters obtained by previous experiments with citations a brief comparison is made with a traditional manual classification system it is shown that the mechanical procedure is capable of achieving simultaneous average relevance and recall figures above 80
CISI	probabilistic models for automatic indexing this paper is developed in two stages the first stage describes an experiment that explores properties of the class of words that are not useful in conveying subject meaning and distinguishes them from those classes of words that do convey subject meaning to various degrees in particular we study the clustering properties of these words the analysis is based on statistical properties alone and techniques are introduced that may be of value in other areas of information science on the basis of the results of this experiment a model of word occurrences is introduced and discussed later papers by us and by harter will apply this model to indexing
CISI	terse literatures i terse conclusions terse conclusion prompt literatures of organized terse conclusions may increase ability to keep up in a subject reduce need for translation and make information available promptly
CISI	functions of a man machine interactive information retrieval system an effective man machine interactive retrieval system is not achieved by simply placing a terminal on each end of an existing machine retrieval system an interactive system requires a sequence of steps in which man and machine alternately take action it should also provide different levels of services to experienced and inexperienced searchers recognize the difference between a narrow and broad query furnish clues as to the next direction to be searched recognize the data base dynamically as the searcher changes his viewpoint provide a ranking of responses in the most likely sequence and offer the searcher the option of overriding the ranking when a particular term is of extreme significance an online interactive system meeting many of these needs has been developed and tested the objectives of the development of this system browser was to investigate the effectiveness of a free form query with a combinatorial search algorithm and the effectiveness of various techniques and components to facilitate online browsing
CISI	overlap in the lists of journals monitored by biosis cas and ei in april 1970 the biosciences information service of biological abstracts the chemical abstracts service and engineering index inc began a five part study to determine the relationships between and the overlap in coverage in their printed publications and computer readable services this study was designed to provide information needed by these three accessing services for planning future cooperative programs and for reconciling differences in policies and practices so as to make their publications and services more useful to their user communities this paper is based on the first part of the study which compared listings of the journals each service was routinely monitoring as of 1 may 1970 of the 14 592 different journals monitored 1 were monitored by all three of the services 27 were monitored by two of the three services and 72 were monitored by only one of the three services subsequent phases of the study will determine the extent to which the services cover the same articles within the journals
CISI	structure and effectiveness of the citation identifier an operational computer program for automatic identification of case citations in legal literature a computer program for automatic identification of full form case citations in legal literature e g rutherford v geddes 4 wall 220 18 l ed 343 southland industries inc v federal communications commission 1938 69 app d c 82 99 f 2d 117 has been developed by this group and is now operational the level of performance of this program known as the citation identifier is high in a recent computer run the citation identifier scanned ther full texts of 191 randomly selected decisions of u s court of appeals some 400 000 words of running text and located correctly 2 220 full form citations out of a total of 2 227 that is better than 99 of the total only seven misses and three false drops occurred of 2 220 full form citations located correctly 1944 87 were identified perfectly in addition there were 276 partial identifications containing two types of errors 1 partial identifications in which some citation terms were mistakenly lopped off by the program short hits and 2 partial identifications that contained words improperly included in the citations long hits both types of errors are for the most part easily correctible and can be largely eliminated by suitable changes in the program the citation identifier operates rather rapidly in a recent test run the total time required to process some 400 000 running words of text was approximately 15 1 2 minutes this speed could be further increased by suitable changes in the computer program an extension of the citation identifier to reduced form citations e g the geddes decision the southland industries case is now in preparation
CISI	title indexes as alerting services in the chemical and life sciences the principles underlying alerting services are discussed general alerting services as distinct from sdi systems need to transfer to their users a large quantity of current but mainly irrelevent information as speedily as possible as title indexes are the easiest to prepare and are therefore common the user needs to know how much significant information is not discernible from a documents title this is estimated to be 20 25 but can vary with subject and type of information sought if a search of say chemical titles is made ignoring synonyms but allowing for all syntactical variants only about one third of the significant information will be recovered synonyms and other nomenclature problems are discussed delay times and time of use are the two most important factors in evaluating an alerting service and are reviewed for some typical services
CISI	evaluation of a kwic index for library literature a librarian attempting to do a literature search currently faces an eight month gap in access to the literature of his field through library literature in april 1968 librarians made a rare examination of their own literature and considered this gap and other information problems in librarianship the albany conference on the bibliographic control of library science literature recommended the establishment of a fast announcement service for library schools 1 a monthly keyword in context kwic index serving the whole range of information oriented professions was a specific proposal which was favored by one conference group to meet the need for current information 2
CISI	the practice of charging users for information services a state of the art report the state of the art literature review disclosed that society has not yet come to the point that paying for library information services is a common thing it was also found that a sound basis for determining the costs of the services   let alone charge for them   does not exist while some data on specific cost for unit operations are available it is very difficult to compare the data and arrive at meaningful figures nevertheless there is an indication that large operating centers are becoming concerned with cost to the point that they are cost according their operations which would permit them to establish realistic fees for their services
CISI	towards a metascience of information informatology arguments are advanced to suggest that information and operations on information are phenomena the principles of which provide the basis for a metascience of information informatology the fundamental character of the phenomena is evidenced in the operations executed during the processing and communication functions the role of the metascience is dictated by several factors namely the need for a common basis upon which all information  oriented specialized sciences and technologies can be understood and studied a common framework and language for all scientists and technologists concerned in some form or other with information on one side and mans relationship to the phenomena on the other side the content of the postulated metascience of information is circumscribed by a list of specific questions and problems for which the science has to provide answers and solutions it is suggested that an educational concept responsive to the needs of metascience of information be developed and implemented
CISI	an evaluation of index medicus and medlars in the field of ophthalmology an evaluation of the performance of index medicus and medlars in the field of ophthalmology is presented using data generated by a separate study medlars performance figures gave a screened precision ratio of 54 and a recall ratio of 42 over the same set of questions index medicus had a screened precision ratio of 53 and a recall ratio of 46 results for index medicus alone over a large set of questions gave a 73 screened precision ratio and a 47 recall ratio a random sample of medlars and index medicus precision and recall failures showed that most of the index medicus recall failures resulted from manual searcher omission the major causes of medlars precision failures were inadequate indexing terminalogy to express concepts and attempts at providing too exhaustive a search
CISI	obsolescence of special library periodicals sampling errors and utility contours problems arising in the measurement of the rates of obsolescence of the sets of periodicals taken by special libraries are discussed the relatively large errors that arise in sampling the negative exponential distribution are analyzed because they may account for some of the discrepancies reported and because they indicate the need for firmer statistical control of work on obsolescence than has yet been generally appreciated when the rate of decline has been satisfactorily established there still remains the problem of deciding how to apply it issues of those periodicals that contribute most productively should be retained for a longer period than those of periodicals that contribute less to solve this problem the concept of utility contours is introduced and exemplified in the design of a p library it is argued that no discarding policy is likely to be generally applicable every special library must be regarded as a special case rather than suggest new measurements therefore the paper offers simple graphical techniques that are applicable to any other special case
CISI	cardiovascular serial literature characteristics productive journals and abstracting indexing coverage two groups of journals were identified as potential sources for cardiovascular c v information the first group consists of 78 c v specialty journals identified as cardiovascular from the title these 78 emanate from 24 countries with about one half of the specialty journals being published by 28 national and international societies the second group of journals is composed of those journals used by grantees of the national heart institute nhi to publish their findings in fiscal 1967 5 860 papers appearing in 789 journals were reported to nhi taking the grantees of nhi as being representative of u s c v researchers it was found that the specialty journals were not the most quantitatively fertile sources of c v information   only about 14 of american c v papers were published there the remaining 86 of the literature was widely dispersed throughout 766 nonspecialty c v journals the extent of bibliographic control by the major indexing and abstracting services was found to be more extensive for the top ranking journals in the nhi sample than for the group of c v specialty journals
CISI	are titles of chemical papers becoming more informative the efficiency of key work in context kwic permuted title indexes and their numerous variations is highly dependent upon authors choices of titles for their papers titles are important not only in commercial services such as chemical titles basic current contents and ca condensates but also in scanning primary journals and in traditional library services such as bibliographies it is generally believed and often stated that titles of chemical papers are becoming more informative as authors become increasingly aware of the importance of titles as carriers of information the present study was undertaken to test whether 1 titles of chemical papers are becoming more informative and 2 whether uninformative titles of chemical papers are being eliminated since the advent of the kwic index in 1958 the first hypothesis was tested by comparing titles published in 1948 1958 and 1968 by the following criteria 1 a count of substantive words in the title 2 a count of all word matches between title and 10 leading substantive words selected from the abstract with and without the use of a thesaurus and 3 a count of word matches between title and 10 leading substantive words selected from the abstract with and without the use of a thesaurus the second hypothesis was tested by comparing a count of short titles with 3 or less substantive words published in 1948 1958 and 1968 results confirm that uninformative titles of chemical papers are being eliminated and that informative titles are becoming more informative since the advent of the kwic index
CISI	toward a theory of indexing  ii the purpose of this paper is to present the elements of a basis for a theory of information storage and retrieval it is believed that this theory can best be formulated in terms of a general theory of indexing after stating basic premises and defining essential concepts the relationship between a theory of indexing and a theory of information storage and retrieval is considered the similarities between the indexing process and the general communication process are discussed and indexing is viewed as an order increasing i e entropy decreasing operation the concept of a theoretical index is developed and contrasted with real world indexing systems the relationship between query formulation retrieval and benefit is discussed and these notions are then related to the human performance variable it is believed that the ideas presented in this paper provide a useful framework for more detailed investigations into the indexing process
CISI	the cost effectiveness analysis of information retrieval and dissemination systems a distinction is made between cost effectiveness analysis and cost benefits analysis as applied to information systems and the relationship between costs performance and benefits is discussed some factors influencing the cost effectiveness of retrieval and dissemination systems are identified various aspects of system operation that are susceptible to cost effectiveness analysis are discussed including system coverage indexing policies and procedures system vocabulary searching procedures and mode of interaction between system and user possible tradeoffs between input and output costs and the effects of these tradeoffs on cost effectiveness are presented
CISI	some remarks on elitism in information and the invisible college phenomenon in science let me remind you of that famous place in dickins pickwick papers where we hear of a researcher who composed a copious review on chinese metaphysics with the aid only of the encyclopedia britannica which contained absolutely no information on that subject the technique used we are told with a nudge of superiority was to read for metaphysics under the letter m and for china under the letter c and to combine the information i feel that we may be performing just such a miracle of creative juxtaposition when we assume that scientific information is just some special variety of information that contains queer words like potassium permanganate pi r squared and numbers like 2 71828 we suppose too that scientific libraries are just libraries that happen to be full of scientific books and that the best possible technical librarian would be somebody who had picked up a library qualification and combined it with the appropriate sort of technical qualification there is as they used to say no mixture of ingredients but a genuine chemical compound i wish to point out two simple facts there is more to scholarship than the mere cumulation storage and retrieval of information and there is about science and technology something intrinsically different from mere scholarship
CISI	human factors in the design of an interactive library system elms experimental library management system is an experimental system for total library management operating on line with an ibm 360 through ibm 2260 and 2741 terminals the system is designed to handle large amounts of highly variable information which it processes on command giving on line computer service for all library operations at the same time it must accommodate the different needs and skills of a broad range of library users from new patrons to well trained librarians such a system presents programming problems that will be typical of large interactive computer systems in the seventies this paper discusses elms features that facilitate user interaction and may prove useful in similar systems techniques for tutoring the user display format one question one answer displays and kwic indexing adaptability for the experienced user command chains and a standard set of four letter mnemonic codes for higher level control minimization of keying line numbers one character mnemonic codes used with procedures and use of default conditions performance of clerical tasks by exception notification and collection of operational statistics to help improve the system
CISI	on line systems promise and pitfalls interactive systems in existence for nearly 15 years are becoming increasingly important both for information retrieval and library support operations the virtues of these systems are speed intimacy and   if time sharing is involved   economy the major problems are the cost of the large computers and files necessary for bibliographic data the still  high cost of communications and the generally poor design of the user  system interfaces the desirable features of on line retrieval interfaces are only now being defined and tested in a systematic way e g by the national library of medicine in its aim twx nationwide experimental retrieval service system implementers must in addition to engineering the right capabilities into on line systems also make a careful concerted effort to engineer user acceptance common pitfalls here include overselling system capabilities and failure to take into account the social context around the user terminal the major national problem is to avoid or limit wasteful and expensive duplication in providing nationwide search access to the hundreds of public and private data bases that will be readily available during the next few years we do not need technological breakthroughs to exploit the potential of on line systems but we do need breakthroughs in organizing for technological change
CISI	selected results from an inquiry into testing of information retrieval systems a variety of aspects related to testing of retrieval systems were examined a model of a retrieval system together with a set of measures and a methodology for performance testing were developed in the main experiment the effect on performance of the following variables was tested sources of indexing indexing languages coding schemes question analyses search strategies and formats of output in addition a series of separate experiments was carried out to investigate the problems of controls in experimentation with ir systems the main conclusions the human factor appears to be the main variable in all components of an ir system length of indexes affects performance considerably more than indexing languages question analyses and search strategies to affect performance to a great extent   as much if not more than indexing retrieval systems seem to be able to perform at present only on a general level failing to be at the same time comprehensive and specific it seems that testing of total ir systems controlling and monitoring all factors environmental and systems related is not possible at present
CISI	what makes an automatic keyword classification effective though the idea of constructing a keyword classification for retrieval purposes automatically is not a new one comparatively few systematic experiments have been carried out in this area and while many suggestions have been put forward not enough is known about the behaviour of automatic keyword classifications and hence about the properties such classifications should have and the ways they should be used in previous experiments we showed that some forms of classification could give good results and this paper describes a further series of tests designed to examine this sort of classification in more detail with a view to establishing the optimum forms of classification and procedures for using them in different retrieval situations these tests demonstrate that further improvements in performance over that for unclassified keywords can be obtained and that definite conclusions can be drawn about the correct approach to classification for collections like the test one the best results are given when grouping is confined to strongly connected nonfrequent keywords when the classification is used to provide additional rather than alternative indexing terms particularly for requests and when matching is controlled by keyword frequency
CISI	machine assisted approach to general reference materials a collection of 144 general reference works was analyzed and encoded according to 254 identifiable characteristics of services and contained data comprising an approach language expressing search parametrs in response to a request submitted at on line terminal the refsearch system retrieves the names of those works who profiles meet or exceed the specification the background and rationale of the system is discussed its current use in the school of librarianship university of california and its potential for direct service to library patrons
CISI	curricula in information science analysis and development the curriculum committee of the special interest group education information science of asis is charged with the responsibility for determining the scope and characteristics of information science programs in the us and canada in terms of curriculum developments and course offerings to fulfill this responsibility questionnaires were developed to elicit reliable information concerning courses being offered relating to information storage and retrieval information science and or documentation the data requested included course levels pre  and post requisite courses textbooks used topics covered frequency with which offered etc responses were received from 45 schools providing information about 185 courses and 242 topics using several methods of clustering the data it was difficult to arrive at firm results because of the diversity and scatter of the topics included in this field it was therefore decided to hold a workshop of experts which would examine the validity of the questionnaire results this workshop using the delphi technique to arrive at consensus was held at the university of pittsburgh on september 21 23 1970 sixteen specialists in the field representing universities industry and government were brought together to participate consensus was reached in identifying nine factors which contribute to the curriculum in information science and seven courses which constitute the core for the masters program the topics to be included in each of these courses were also isolated
CISI	on the evaluation of information science the emergence and development of information science within its wider disciplinary framework is interpreted information science is approached as one of a modern generation of communication or behavioral disciplines which emerged almost simultaneously around world war ii consequently an attempt is made to discern the evolution of relationship between information science and other generation disciplines the internal development of information science is first sketched second possible relationship and roles of information science within a potentially emergent suprasystem of knowledge are discussed
CISI	compound words a problem in post coordinate retrieval systems compound words cause some difficulty in post coordinate indexing systems if too many are fractured or the wrong categories are selected for fracturing noise will be produced at unacceptable levels on retrieval various prior suggestions for handling compound terms are examined which include those for pre coordinated or rotated indexes the syntactic origins are also explored and it is found that many compound words hinge on a prepositional relationship between the components and that this relationship can be applied to decision making other compound words are in effect abbreviated statements from longer phrases while some are influenced by the presence of a verb like form these syntactic influences together with some of the philosophy from earlier studies   especially that of the force required to fracture a term have been combined to produce a set of rules which have been employed at the national rubber producers research association nrpra for over two years these have greatly eased decision making and have enabled the thesaural vocabulary to be made more consistent it is also suggested that the rules have some bearing on the application of roles especially if these are employed on a pre coordinate basis
CISI	some implications of automatic recognition of bibliographic elements a theoretical approach to the problem of converting printed bibliographic records to machine readable form is developed based on principles of system analysis experience from several recent projects conducted by the institute of library research university of california are used to illustrate how this theoretical approach is currently being tested prior to implementation in a large scale conversion project
CISI	informal communication among scientists in sleep research at the frontiers of an active area of science social structure based upon communication is demonstrated using sociometric techniques an informal communication network was identified which included 73 of the scientists within the network was a core group of scientists who were the focus of a disproportionately large number of contacts and who were differentiated from others by greater productivity higher citation record and wider readership information transferred to these scientists is so situated that it could be transmitted to 95 of the network scientists through one intermediary scientist or less
CISI	the efficiency of medlars titles for retrieval previous research has indicated that the titles rather than index terms would in the standard medlars system gave lower recall but higher precision a title searching technique is described which allows the number of references retrieved to be fixed before a search commences with this technique the greater applicability of title terms offsets their relative paucity the title searching technique is tested using queries put to medlars these queries were not specially solicited for the test title searching is compared with the standard medlars index term search and with an index term search with fixed output size for equal output sizes title searching retrieves 4 relevant references for every 5 retrieved by index term searching thus the relative retrieval efficiency of title and index terms is so close that the choice of one method or the other must be primarily on economic grounds
CISI	comparison of document data bases this paper presents a detailed analysis of the content and format of seven machine readable bibliographic data bases chemical abstract service condensates chemical and biological activities and polymer science and technology biosciences information services ba previews including biological abstracts and bioreseach index institute for science information source tape and engineering index compendex selected issue test tapes of each data base were printed and checked for the types of data that were contained in the issue and the methods in which the data were formatted this paper compared the physical formats of the tapes and describes the varied treatments given to such data elements as authors titles abstracts etc comparison of data bases requires common use of terms all terms are defined at the beginning of the paper the authors found great discrepancies in the presentation of essentially similar bibliographic data and they offer some suggestions for mitigating the discrepancies by use of standards
CISI	citations references and the growth of scientific literature a model of dynamic interaction a mathematical model is presented which explains the observed exponential growth rates of citations and references in a scientific discipline the independent variables are the growth rate of the number of articles published and the decay rate of citation of old literature it is shown how the parameters of the model can be estimated
CISI	interface design for an interactive information retrieval system a literature survey and a research system description this article focuses on the human interaction characteristics of an information retrieval system suggests some design considerations to improve man machine cooperation and describes a research system at stanford that is exploring some of these techniques librarians can only be of limited assistance in helping the naive user formulate an unstructured feeling in his mind into an appropriate search query that maps into the retrieval system consequently the process of query formulation by the user interactively with the information available in te system remains one of the principal problems in information retrieval today in an attempt to solve this problem by improving the interface communication between man and the computer we have pursued the objective of displaying hierarchically structured index trees on a crt in a decision tree format permitting the user merely to point with a light pen at alternatives which seem most appropriate to him using his passive rather than his active vocabulary expands his interaction vocabulary by at least an order of magnitude moreover a hierarchically displayed index is a modified thesaurus and may be augmented by adding lateral links to provide semantic assistance to the user a hierarchical structure was chosen because it seems to replicate the structure of cognitive thought processes most closely thus allowing the simplest most direct transfer of the mans problem into the structure and vocabulary of the system
CISI	improving a field based eric like information system this is a period for rapid growth in information systems for the sciences and professions information centers are springing up across the country federal agencies and private groups are both collaborating and competing to establish comprehensive systems changing the librarys name to information center is more than linguistic faddism new active roles subordinate the librarys traditional passive role as a preserver and codifier of knowledge information center bears analogy to economic center and transportation center like these centers its significance is in transaction the significance of a transportation center lies in routes to other centers the significance of an information center lies in communication lines to knowledge producers and knowledge users information centers are judged by their information throughput not by their holdings
CISI	a new comparison between conventional indexing medlars and automatic text processing smart a new testing process is described designed to compare conventional retrieval medlars and automatic text analysis methods smart the results obtained with a collection of documents chosen independently of either smart or medlars indicate that a simple automatic extraction of keywords from document abstracts produces a 30 to 40 percent loss compared with medlars indexing a replacement of the unranked boolean searches used in medlars by the standard ranked output normally provided by smart reduces the loss to between 15 and 20 percent when automatically generated word control list or a thesaurus is used as part of the smart analysis the results are comparable in effectiveness to those obtained by the intellectual medlars indexing finally the incorporation of user feedback procedures into smart furnishes an improvement over the normal medlars output of 15 to 30 percent one concludes again that no technical justification exists for maintaining controlled manual indexing in operational retrieval environments
CISI	report on the evaluation of an experimental computer based current awareness service for chemists a selected sample of u k university industrial and government scientists were given a current awareness service for 18 months in order to investigate the practicability and problems of such a service six hundred profiles were run using the natural language data bases chemical titles and chemical biological activities produced by chemical abstracts service precision and recall were measured and correlations between profile performance and such factors as subject area and profile logic were investigated statistically precision and recall failures were analyzed and various improvements to the system were suggested as a consequence it was concluded that a viable computerized current awareness service based on searching natural language could be created
CISI	the development of a semantic differential to assess users attitudes towards an on line interactive reference retrieval system a semantic differential sd is a commonly used instrument which can be used to reliably measure attitude toward a variety of objects or concepts each sd consists of a series of bipolar adjective scales on which a respondent reacts in relation to the object or concept of interest to interpret completed sds it simplifies the procedures and aids in the development of theory if the adjective scales are grouped into one or more independent clusters the primary purpose of this study was to identify those clusters or dimensions applied by a user of an on line user oriented reference retrieval system when he reacts toward such a system seventy one who used or were familiar with a working on line reference retrieval system completed a packet of 20 sds each consisting of the same 19 adjective scales the correlations among the scales were factor analyzed three independent dimensions were identified factor i was labeled evaluative specific and accounted for over 23 of the total variance factor ii was called desirability it accounted for over 17 of the total variance and factor iii entitled enormity accounted for over 10 of the total variance another analysis showed the factor structure to be highly reliable therefore if the derived three dimensional structure underlies users attitudes toward a more general class of retrieval systems then undimensional or unstructured system evaluation of users attitudes will be simplistic and possibly misleading in order to construct a working semantic differential 10 adjective scales were identified which best represented the three dimensions brief instructions are included which outline how to use this sd the discussion is mainly concerned with the obtained factor structure and the need for a predicative replication of the study
CISI	what information dissemination studies imply concerning the design of on line reference retrieval systems the use of an on line computer system for locating bibliographic citations has been hailed as an important innovation for coping with the information explosion however on line reference retrieval is only one element in a large social system of information dissemination to have a widespread impact an on line system must compete successfully with a multitude of other sources of references this paper reviews studies of information dissemination as a basis for determining how on line retrieval can best compete it recommends the functional groups for whom an on line system should be designed and the forms of written media that should be included in the systems initial data base finally it presents criteria the system should satisfy to be as widely used and as comprehensive as other reference retrieval methods
CISI	interactive search of bibliographic data bases in an academic environment a surprising difference is found in the acceptance of on line bibliographic search between university research workers and students in the classroom the typical research worker even after careful preparation and individual help abandons the on line system in favor of more traditional searching techniques the student and the seminar participant on the other hand take to this new tool with enthusiasm and profit bibliographic data bases in physics astronomy and urban systems are available to users through on line access to the remote information query system riqs examples of introductory on line sessions are presented and a report of one of the professors participating is included
CISI	citation patterns fo the cardiovascular serial literature in an attempt to further amplify the characteristics of the cardiovascular serial literature citation patterns were studied as previously shown one third of the 5 860 papers from the national heart institute grantees for 1967 appeared within 13 journals 3 after the exclusion of the abstract journals the remaining journals were used to obtain a basic pool of 300 cardiovascular related articles science citation index was used to gather statistics relative to citing author journal and year the 300 articles in the basic pool were cited a total of 2 545 times during this four year period 1967 1970 the figures concerning citation rate by year serve to uphold the idea that journal citation reaches a peak during the third year after publication also some definite patterns of self citation were noted it was found that when analyzed on the basis of first author 15 percent of the 2 545 citations were self citations the ten basic journals tend to be cited mostly within themselves one third of the citations were found in these journals although the citations were found throughout 349 journals indicating an extensive scatter a relatively high percentage of papers were found in few journals
CISI	the use patterns of physics journals in a large academic research library the purpose of this investigation was to reveal the use of patterns of the physics journals in the m i t science library the findings are based upon an analysis of actual use data recorded from all volumes and issues left by library users on study tables and on trucks in the photocopy area from march 15 to june 31 1971 the science library contains some 220 physics journals the study reveals that only 138 journals 62 7 were used even once during the 3 1 2 month interval a core of 49 journals supplies 90 of use and these items would cost 51 1 of the total single subscription costs of the 138 used titles 52 3 of use occurs in journal volumes less than 6 years old english is the most used language of physics journals and the english journals account for 95 3 of use american journals 57 2 of which are published by the american institute of physics supply 59 4 of the total use
CISI	a cost model for evaluating information retrieval systems this paper develops a mathematical model for use in studying how to minimize the cost of operating a mechanized retrieval system through the use of cost analysis the model provides a method for comparative evaluation between information retrieval systems the cost model divides the costs of a retrieval system into two components system costs and user costs in addition it suggests that a trade off exists between the performance level of the system and the combination of user and systems time that is expended in working with the system this minimizes the total cost of operating the system the allocation is done for a given performance level and for a given cost per unit of user and system time
CISI	a bibliometric analysis of certain information science literature several bibliometric techniques previously applied to separate scientific literatures were used together in the analysis of a single corpus of journal articles relating to information science techniques included are a bradford analysis b epidemic analysis c identification of research front and d bibliographic coupling similar analysis was made of writings cited by the main corpus articles and of the literature which in turn cites the main corpus results were analyzed in terms of structure and processes observable in patterns of authorship publication and citation their significance is discussed with potential application of the method to the solution of problems in the management of large research libraries
CISI	on line serials control system in a large biomedical library 1 description of the system an on line serials control system with particular emphasis on storage and maintenance concepts is described the system operational since january 1971 has evolved from a former batch card system and remains completely compatible with it the system allows real time display and updating of all elements of the file consequently all check in bindery and claims operations as well as new entries and data field changes are accomplished on a real time basis all programs are in pl 1 required equipment is an ibm time shared facility with 100 k memory available for the applications programs and ibm 2260 display units this article is the first of three the second is concerned with an analysis of inverted file retrieval features and the third compares the operation of the on line with the batch system comparable manual operations and discusses costs
CISI	interrelationships of scientific journals a series of models of the interrelationship of scientific journals has been developed from the cross citing amongst 275 journals in mathematics physics chemistry biochemistry and biology the data source was the journal citation index jci a file derived from the science citation index the jci consists of a journal by journal tabulation of citings to and from each journal in the index a large amount of consistency was found between the citing characteristics of the journals in the different scientific fields with quite clear boundaries between fields and a few well known cross disciplinary journals as cross field information links the separate disciplines appear to relate to each other in an orderly manner with a natural sequence mathematics    physics    chemistry    biochemistry    biology within disciplines the journals form fully transitive hierarchies with very few relational conflicts
CISI	managing an uncontrolled vocabulary ex post facto initiated as an experiment supported by the division of medicinal chemistry of walter reed army institute of research the operational retrospective retrieval service offered by biosis now in its eighth year exploits a file created essentially without vocabulary control the file comprises some 40 million index access points to 1 87 million references in research biology announced in biological abstracts and bioresearch index since september 1959 a pragmatic program of file building criteria has been pursued originally with modest support from the office of science information service of the national science foundation which has provided improved retrieval and an annual summary of the vocabulary of the literature available to anyone interested 1
CISI	on line serials control system on a large biomedical library part ii evaluation of retrieval features the on line serials control system in use at ucla biomedical library utilizes an inverted file for its primary technique the correct title is reached with a entry about 80 of the time by using average of three title words a detailed profile of title structure and search scheme is given the major determinants of the scheme are evaluated on a performance and cost basis
CISI	dialectical inquiring systems a new methodology for information science a taxonomy for modeling information systems is presented the taxonomy derives from the history of modern epistemology epistemology is used as a prescriptive modeling basis because 1 the fundamental problems of epistemology are concerned with information and 2 because the history of epistemology identifies any archetypal ways that men have conceived of information and of models it is shown how the different models of epistemology can be made scientifically operational through the use of a special kind of systems analysis finally the results of a preliminary experiment based on one of the models are presented in the form of prescriptive rules for the design of future experiments
CISI	overlap among the journal articles selected for coverage by biosis cas and ei of 14 592 primary journals being collectively monitored by the biosciences information service of biological abstracts biosis the chemical abstracts service cas and engineering index inc ei on 1 may 1970 only 4081 were being monitored by two or more of the services the extent to which all three or any two of these services select the same journal article for coverage was determined by examining each services selection records for the july 1969 june 1970 issues of these 4081 overlap journals the maximum possible journal article overlap among biosis cas and ei was found to be 822 articles and between biosis and ei 1428 articles the journal article overlap between biosis and cas was found to be 48 856 articles and between cas and ei 21 583 articles
CISI	cost effectiveness of current awareness sources in the pharmaceutical industry in a previous paper from the wellcome foundation scott et al 1971 a technique was described for measuring the usefulness of a commercial data base by comparing the choice of papers and of indexing terms to those chosen as relevant to the organization in this paper we are comparing the cost effectiveness of several commercial data bases journal scanning by information scientists and the impact of private communication
CISI	clinician search for information the use of a medical library by members of the faculty of a medical school was studied by questionnaire in an effort to ascertain the part the library played among channels of communication in work related information searches the study described the population of users and the kinds of sources they utilized in an information search in an effort to identify the factors influencing their choice of kinds of sources and leading to the possibility of predicting use of kinds of source once the characteristics of the users were known it brought out a high use of sources which are accessible and easy to use the tabulations show the importance of co workers in informal communication low delegation of documentation tasks to libraries was apparent the main user of the library studied was a clinician in the area of internal medicine who used journal articles about diseases for information to use in the treatment of his patients the recommendations were made that journals should be shelved accessibly with index medicus nearby books might be shelved less accessibly telephone access to the library is of major importance as is the provision of adequate photocopying facilities
CISI	on selecting a measure of retrieval effectiveness it is argued that a users subjective evaluation of the personal utility of a retrieval systems output to him if it could be properly quantified would be a near ideal measure of retrieval effectiveness a hypothetical methodology is presented for measuring this utility by means of an elicitation procedure because the hypothetical methodology is impractical compromise methods are outlined and their underlying simplifying assumptions are discussed the more plausible the simplifying assumptions on which a performance measure is based the better the measure this along with evidence gleaned from validation experiments of a certain kind is suggested as a criterion for selecting or deriving the best measure of effectiveness to use under given test conditions
CISI	the user interface for interactive bibliographic searching an analysis of the attitudes of nineteen information scientists since little substantiated evidence exists concerning the features that should of should not be included in the man machine interface of interactive bibliographic search and retrieval ibsr systems an informal survey tapping the opinions of scientists active in this research area was conducted an analysis of the responses showed a significant level of agreement concerning interface features
CISI	theoretical foundations of thesaurus construction and some methodological considerations for thesaurus updating it was argued that the present day thesaurus construction and maintenance rules and conventions are not theoretically based for this reason there are few rules and conventions for updating a thesaurus consequently most of the thesauri adopted by operating information storage and retrieval systems are not systematically updated in order to investigate how thesauri are actually updated a survey was conducted the working hypothesis was that the communication process between authors and readers is linear in nature one way communication allowing no reciprocal feedback if a thesaurus utilized in a system is not updated by both indexers and question negotiators findings show that thesauri viewed from the communications point of view do not allow a cybernetic process of communication both way communication the survey indicated that the present practice of updating thesauri is largely done by indexers alone no attempt was made to develop a theory of thesaurus construction and updating it was however argued that such a theory if developed should at least account for the concepts of meaning and knowledge within this theoretical framework two techniques are suggested to be considered for the systematic updating of a thesaurus
CISI	the environment of classification the concept of mutual exclusivity it has been suggested that information science is still of the stage of alchemy if this is so then mutual exclusivity must form its philosophers stone mutual exclusivity appears to be alien to the observable universe that this is so is displayed through a series of examples some of these relate to everyday things like trees beaches and man himself whilst others relate to more obscure phenomena like continental drift and black holes the act of observation is also considered as this has a considerable bearing on the problem nevertheless mutual exclusivity must form part of mans mental powers and this has found expression in the relatively exclusive series of symbols used in communication the dangers of exclusive thinking in relation to environmental problems are considered and this results in a paradox which is probably unresolvable finally it is observed that out standing genius appears to pay scant regard to existing classifications and is more likely to be involved in an integrated approach to problems
CISI	promotion of information services an evaluation of alternative approaches this article deals with the promotion of information services specifically the formation and subsequent evaluation of different promotional programs for selective dissemination of information sdi services provided by the mechanized information center mic at the ohio state university three programs    opinion leadership blitz and telephone solicitation    were developed data were collected to show for each of the programs 1 the level of market penetration achieved 2 the level of user satisfaction generated from the service 3 the effect in terms of influence of the various media employed and 4 cost effectiveness data analysis focused on a determination of the most effective methods to promote sdi services
CISI	a novel philosophy for the design of information storage and retrieval systems appropriate for the 70s the philosophy of a systems approach to the design of information storage and retrieval systems is suggested in which the computer is recognized in its proper perspective as a powerful and effective alternative tool this philosophy is in contrast to a prevalent philosophy of the 60s in which many information systems designers touted the computer as the answer to all information storage and retrieval situations important principles of information system design incorporated within the framework of the novel philosophy for the 70s are presented these are the performance of users needs studies by the representative small group technique the analysis of users needs including their rank ordering by priority the selection and adaptation for a specific application of a suitable existent information storage and retrieval system from those available the involvement of potential users in the system design by establishing a model with which they can interact and provide feedback and the final design of a cost effective system a number of pitfalls arising from earlier design methodologies are pointed out and the avoidance of these pitfalls by adopting a true systems approach is discussed
CISI	a general statistical model for estimating future demand levels of data base utilization within an information retrieval organization a statistical model for characterizing the growth patterns of data base utilization and for estimating future utilization levels of demand has been developed for information retrieval organizations the model developed is y b 1   e  at where y is the number of users of a data base at time t and a and b are parameters to be estimated illustrations of the model applied to a typical information retrieval organization are given and discussed
CISI	co citation in the scientific literature a new measure of the relationship between two documents a new form of document coupling called co citation is defined as the frequency with which two documents are cited together the co citation frequency of two scientific papers can be determined by comparing lists of citing documents in the science citation index and counting identical entries networks of co cited papers can be generated for specific scientific specialties and an example is drawn from the literature of particle physics co citation patterns are found to differ significantly from bibliographic coupling patterns but to agree generally with patterns of direct citation clusters of co cited papers provide a new way to study the specialty structure of science they may provide a new approach to indexing and to the creation of sdi profiles
CISI	use of an automatic text analyzer in preparation of sdi profiles the conventional method of preparing sdi selective dissemination of information profiles often necessitates detailed interview sessions between the client and one or more information scientists this research shows that by submitting samples of the clients recent professional reading material to automatic text analysis sdi profiles can be prepared that result in significantly higher initial recall scores than do those prepared by conventional techniques relevance scores are not significantly different
CISI	on selecting a measure of retrieval effectiveness part ii implementation of the philosophy it was argued in part i see jasis march april 1973 p 87 that the best way to evaluate a retrieval system is in principle at least to elicit subjective estimates of the systems utility to its users quantified in terms of the numbers of utilities e g dollars they would have been willing to give up in exchange for the privilege of using the system and a naive methodology was outlined for evaluating retrieval systems on this basis but the impracticality of the naive evaluation procedure as it stands raises the questions how can one decide which practical measure is likely to yield results most closely resembling those of the naive methodology and how can one tell whether the resemblance is close enough to make applying the measure worth while in the present paper two kinds of solution to these problems are taken up the first answers the questions in terms of the reasonableness of the simplifying assumptions needed to get from the naive measure to the proposed substitute the second answers it by experimentation
CISI	clustering of scientific journals a cluster analysis procedure is described in which 188 journals in the discipline of physics chemistry and molecular biology are grouped into clusters most of the clusters are easily identified as subdisciplinary subject areas the data source was the cross citing amongst the journals derived from the journal citation index jci a file derived in turn from the science citation index sci the jci consists of journal by journal tabulation of citings to and from each journal processed in the sci two step citation maps linking the clusters are presented for each discipline within the disciplines the clusters of journals form fully transitive hierarchies with very few relational conflicts
CISI	text searching retrieval of answer sentences and other answer passages some new text searching retrieval techniques are described which retrieve not documents but sentences from documents and sometimes on occasions determined by the computer multi sentence sequences since the goal of the techniques is retrieval of answer providing documents answer passages are retrieved an answer passage is a passage which is either answer providing or answer indicative i e it permits inferring that the document containing it is answer providing in most cases answer sentences i e single sentence answer passages are retrieved this has great advantages for screening retrieval output two new automatic procedures for measuring closeness of relation between clue words in a sentence are described one approximates syntactic closeness by counting the number of intervening syntactic joints roughly speaking prepositions conjunctions and punctuation marks between successive clue words the other measure uses word proximity in a new way the two measures perform about equally well the computer uses enclosure and connector words for determining when a multi sentence passage should be retrieved however no procedure was found in this study for retrieving multi paragraph answer passages which were the only answer passages occurring in 6 of the papers in a test of the techniques they failed to retrieve two answer providing documents 7 of those to be retrieved because of one multi paragraph answer passage and one complete failure of clue word selection for the other answer providing documents they retrieved at all recall levels with greater precision than smart which has produced the best previously reported recall precision results the retrieval questions mostly from real users and documents used in this study were from the field of information science the results of the study are surprisingly good for retrieval in such a soft science and it is reasonable to hope that in less soft sciences and technologies the techniques described will work even better on this basis a dissemination and retrieval system of the near future is predicted
CISI	breaking the communication barrier between searcher and literature file an interactive guide the challenges of design of programming systems file organization and manipulation and user oriented query languages have held the spotlight in the development of data processing support to systems for retrieval of scientific literature at biosis development of such a system from the pragmatic viewpoint of providing viable self supporting retrieval service from a data base of more than two million references has resulted in focusing attention on supporting the formulation of the information need into an effective computer search specification developed under cps and now implemented under cics the program claims no novelty of structure or technique but constitutes an innovation in application and goal with primary emphasis on accommodating the behavior of a user not previously knowledgeable about the structure indexing language and detailed content of a machine based references file
CISI	densities of use and absence of obsolescence in physics journals at m i t chens data for the raw frequency of use of 138 physics journals in the science library at m i t are re examined and converted to densities of use per meter of shelf other units of size for obtaining densities and their measurement are discussed there is no evidence for synchronous obsolescence in the 1955 to 1968 volumes of these journals instead there is some statistically significant evidence of greater density of use with greater age similar evidence elsewhere is cited the ranking order for heaviness of use is also radically altered by converting raw frequencies to densities of use it is suggested that for comparing the relative values of different journals or age groups in library use or citation studies analyses of raw frequencies are valueless and indeed potentially dangerously misleading until they are converted to allow for the numbers of available items in each group examined
CISI	costs and effectiveness in the evolution of an information system a case study with budget constraints the problems of cost and effectiveness have advanced to the top of priority list of all information services managers determining and monitoring effectiveness should be cost effective also the author traces the cost effectiveness problems back to the genesis of an information system performance parameters and their shifting in the desired direction are briefly discussed the monthly statement is intended to assist a manager in budgeting and planning and it should also alert him to any irregularities in costs and effectiveness either in time or among individual services if adopted more widely it could even serve as a means of comparison between centers if due consideration is given to varying conditions
CISI	the scientific premises of information science throughout my years of work as an information scientist i have been plagued by a personal and professional sense of doubt with respect to the field a central theme of every conference that i have attended related to what is information science or is information science a science in this paper i hope to take these questions head on i must begin by saying that i do take information science seriously as a science i see it as the quest for understanding of the nature of information and mans interaction with it that we lack so much in this quest for understanding is the greatest challenge of the science i intend to explore the tradition or world view bearing on the scientific study of information the currently prevalent world view is the scientific tradition which extends from the enlightenment to the present i also intend to look critically at what i perceive to be te premises underlying most of our current efforts to understand the phenomenon of information the criticism will by necessity be speculative i intend to stick my neck out not because i can prove my assertions but because i believe these ideas must be discussed
CISI	representation of concept relations using the tosar system of the idc treatise iii on information retrieval theory successful information retrieval from a mechanized file is heavily dependent on the fidelity of the representation of concepts in the particular language of the system and on the predictability of this representation if an index language is employed predictability is guaranteed and the quality of the retrieval is predominantly governed by the fidelity of the representation i e by the extent to which conceptual distortion of the concepts to be represented can be avoided the various index languages vary widely with respect to their fidelity differences in their performance are correspondingly great the lack of fidelity in most of the present day indexing languages is due mainly to insufficient representation of the relationships among concepts we describe a new graphical method of storing and retrieving concept relations of various kinds the points of such a graph are occupied by concepts and the connecting lines between these points represent concept relations in a special field of chemistry these graphs also serve as a kind of presentation of the essentials of a document to the reader that is much more lucid than a natural language text
CISI	making on line search available in an industrial research environment on line interactive searching of several information bases through several service operators was introduced in an industrial research environment thorough knowledge of the information base and its structure in the search system is a major factor of successful searching and differences among search systems do not present serious barriers this new technique was most effectively used when the information specialist and the scientist searched as a team on line searching is now an established search tool at exxon research and engineering company
CISI	a theory of term importance in automatic text analysis a good deal of work has been done over the years in an attempt to use statistical or probabilistic techniques as a basis of automatic indexing and content analysis unfortunately many of these methods are lacking in effectiveness and the more refined procedures are computationally unattractive a new technique known as discrimination value analysis ranks the text words in accordance with how much they are able to discriminate the documents of a collection from each other that is the value of a term depends on how much the average separation between individual documents changes when the given term is assigned for content identification the best words are those which achieve the greatest separation the discrimination value analysis is computationally simple and it assigns a specific role in content analysis to single words juxtaposed words and phrases and word groups or thesaurus categories experimental results are given showing the effectiveness of the technique
CISI	a decision theoretic foundation for indexing the indexing of a document is among the most crucial steps in preparing that document for retrieval the adequacy of the indexing determines the ability of the system to respond to patron requests this paper discusses this process and document retrieval in general on the basis of formal decision theory the basic theoretical approach taken is illustrated by means of a model of word occurrences in documents in the context of a model information system both models are fully defined in this paper though the main purpose of this paper is to provide insights into a very complex process formulae are developed that may prove to be of value for an automated operating system the paper concludes with an interpretation of recall and precision curves as seen from the point of view of decision theory
CISI	creation and use of citation data bases a modest proposal improvement in the production and use of citations to research literature calls for coordination of activities by a number of abstracting and indexing services the ohio college library center oclc has developed a cost effective on line shared cataloging system now in widespread use by u s libraries it could readily serve as a pattern for a system to create and share descriptive indexing on line a proposed system is outlined possible developers are noted and further action is urged
CISI	performing evaluation studies in information science this paper considers conceptual and methodological components of information science evaluation studies the paper discusses the judgmental process of evaluation and the scientific nature of evaluation study in the context of purpose statements criteria the selection of variables and data collection and analysis techniques and requirements of validity reproducibility and reliability industrial value analysis engineering methodology is described and related to assessments of information products and services the state of the art of evaluation study in information science is analyzed with respect to 1 the scope of evaluation studies 2 the use of laboratory type environments 3 the use of surrogate judges 4 selection of variables 5 frequency of study and 6 comparabilty of study results evaluation study is seen as essential to the management of information centers and systems and as having approachable growth potential
CISI	optimal resource allocation in library systems a procedure is developed for optimal allocation of resources among the many processes of a library system queueing theory is used to model processes as either waiting or balking processes the optimal allocation of resources to these processes is defined as that which maximizes the expected value of the decision makers utility function an application of the procedure to a specific library system is discussed
CISI	user training for on line information retrieval systems the early 1970s have clearly shown a trend toward the use of on line systems as the ideal medium for information retrieval the emphasis placed on direct access by the practitioners in the field rather than delegated searches through information specialists leads to the growing need for an efficient design in training transient user groups printed manuals live help audiovisual presentations and on line instructions have all been used with varying degrees of success the author contends that the use of computer assisted instruction in conjunction with the on line information retrieval system is the most promising form of instruction in that the medium itself as well as the message may be used to acquaint the novice searcher with an interactive user system interface
CISI	a probabilistic approach to automatic keyword indexing part i on the distribution of specialty words in a technical literature the problem studied in this research is that of developing a set of formal statistical rules for the purpose of identifying the keywords of a document  words likely to be useful as index terms for that document the research was prompted by the observation made by a number of writers that non specialty words words which possess little value for indexing purposes tend to be distributed at random in a collection of documents in contrast specialty words are not so distributed in part i of the study a mixture of two poisson distributions is examined in detail as a model of specialty word distribution and formulas expressing the three parameters of the model in terms of empirical frequency statistics are derived the fit of the model is tested on an experimental document collection and found to be acceptable for the purposes of the study a measure intended to identify specialty words consistent with the 2 poisson model is proposed and evaluated
CISI	relative effectiveness of titles abstracts and subject headings for machine retrieval from the compendex services we have investigated the relative merits of searching on titles subject headings abstracts free language terms and combinations of these elements the compendex data base was used for this study since it contained all of the data elements of interest in general the results obtained from the experiments indicate that as expected titles alone are not satisfactory for efficient retrieval the combination of titles and abstracts came the closest to 100 retrieval with searching of abstracts alone doing almost as well indexer input although necessary for 100 retrieval in almost all cases was found to be relatively unimportant
CISI	an acquisitions decision model for academic libraries a decision model for book acquisitions has been developed to simulate the intellectual processes used in acquiring these materials in academic libraries it consists of a flow chart weighted inputs and an equation which when solved indicates whether a library should add the title to its collection refer it to a cooperative group defer the decision or drop it altogether inputs to the model need further study and development but the model is a step in defining and quantifying the decision process
CISI	relevance a review of and a framework for the thinking on the notion in information science information science emerged as the third subject along with logic and philosophy to deal with relevance   an elusive human notion the concern with relevance as a key notion in information science is traced to the problems of scientific communication relevance is considered as a measure of the effectiveness of a contact between a source and a destination in a communication process the different views of relevance that emerged are interpreted and related within a framework of communication of knowledge different views arose because relevance was considered at a number of different points in the process of knowledge communication it is suggested that there exists an interlocking interplaying cycle of various systems of relevances
CISI	thesaurus control   the selection grouping and cross referencing of terms for inclusion in a coordinate index word list the selection grouping and cross referencing of the usually single word terms are based on 1 a systematic approach to indexing in depth based on earlier work and resulting in reasonably consistent indexing 2 an analytical approach to word forms in which the following categories are distinguished action forms means material means machine and means man forms states variables and latent properties for each word those forms included in a certain category are represented by a single code the category switching caused by prepositions must be taken into account 3 criteria for term splitting with limited semantic factoring occasionally semantic integration is used 4 critera for dealing with antonyms which are classified as reciprocals complements unequivalent opposites diametrical opposites and reversals 5 introduction of conditional cross referencing 6 recognition of multiword synonyms as the major difficulty in coordinate indexing
CISI	an analytical model of a library network networks and network models of industrial and military systems have received much attention in operation research literature the extension of network modeling to library networks provides some interesting twists of the usual models a general library network is offered a mathematical statement of the network problem is given and the solution of the problem is discussed an example of the use of the model in evaluation and design situations is provided the necessity for further work in both theoretical and applied areas is cited in the summary
CISI	the potential usefulness of catalog access points other than author title and subject library patrons who wish to obtain a known document with which they have had prior personal contact often cannot remember the standard author  title subject information about it with sufficient accuracy to be able to look it up easily in present day card catalogs however they may remember a surprising amount of such nonstandard information as the color of the documents cover or its approximate length could this type of nonstandard information be profitably exploited in computerized catalogs of the future such facilities if available would surely be used for according to catalog usage surveys a majority of todays library patrons seek known documents and of these a substantial minority possess nonstandard information in this report the results of a memory experiment to test the memorability of various types of nonstandard information are described and analyzed a ranking according to relative memorability and potential retrieval usefulness of various nonstandard book features is given it is estimated that if the average patrons nonstandard information were exploited by appropriate retrieval strategies he would only have to search through roughly one five hundredth as many documents as in a random search this reduction factor is great enough to make nonstandard information potentially useful in many situations
CISI	measures of the usefulness of written technical information to chemical researchers the effective transfer of technology involves more than just distributing paper it demands that useful documents be disseminated with a minimum of useless ones for 1 month 10 researchers recorded a sample of the written technical information items that they received 4 months later they were interviewed to determine which of these items had proved useful and in what ways the results indicate that 1 a researcher will call an item useful even if it does not cause him to take some action but only has some significance for him 2 the more the source of an item knows about the needs of the researcher or the more the researcher knows about an item he seeks the more likely it is that the researcher will find the item useful 3 no strong relationships were found between certain readily observable physical arrangements and information behavior and 4 an item may prove useful not because of the information objectively contained in that item but because the item causes a cognitive restructuring of the researchers mind or a free association other studies that restrict their measures of information usefulness to externally observable behavior or that do not carefully define usefulness may not be validly representing usefulness to the researcher
CISI	standards for writing abstracts an abstract as defined here is an abbreviated accurate representation of a document the following recommendations are made for the guidance of authors and editors so that abstracts in primary documents may be both helpful to their readers and reproducible with little or no change in secondary publications and services prepare an abstract for every formal item in journals and proceedings and for each separately published report pamphlet thesis monograph and patent place the abstract as early as possible in the document make the abstract as informative as the document will permit so that readers may decide whether they need to read the entire document state the purpose methods results and conclusions presented in the document either in that order or with initial emphasis on findings make each abstract self contained but concise retain the basic information and tone of the original document keep abstracts of most papers to fewer than 250 words abstracts of reports and theses to fewer than 500 words preferably on one page and abstracts of short communications to fewer than 100 words write most abstracts in a single paragraph normally employ complete connected sentences active verbs ad the third person employ standard nomenclature or define unfamiliar terms abbreviations and symbols the first time they occur in the abstract
CISI	criteria used by research and development engineers in the selection of an information source the criteria employed by engineers in the selection of various technical information channels in problem solving endeavors are investigated the relationships of certain criteria identified in past research to such factors as frequency of channel utilization and the rate at which engineers accept or reject technical information received from specific channels are the focal points of the study a direct relationship is founded between perceived accessibility of information channels and several objective measures of utilization whereas no definite support is found for the hypothesis that the channel perceived highest in technical quality are those used most frequently
CISI	a highly associative document retrieval system this paper describes a document retrieval system implemented with a subset of the medical literature with the exception of the development of a negative dictionary all system operations are completely automatic introduced are methods for computation of term term association factors indexing assignment of term document relevance values and computations for recall and relevance high weights are provided for low frequency terms and retrieval is performed directly from highly connected term document files without elaboration recall and relevance are based on quantitative internal system computations and results are compared with user evaluations
CISI	on relevance probabilistic indexing and information retrieval this paper reports on a novel technique for literature indexing and searching in a mechanized library system the notion of relevance is taken as the key concept in the theory of information retrieval and a comparative concept of relevance is explicated in terms of the theory of probability the resulting technique called probabilistic indexing allows a computing machine given a request for information to make a statistical inference and derive a number called the relevance number for each document which is a measure of the probability that the document will satisfy the given request ranked according to their probable relevance the paper goes on to show that whereas in a conventional library system the cross referencing see and see also is based solely on the semantical closeness between index terms statistical measures of closeness between index terms can be defined and computed thus given an arbitrary request consisting of one or many index term s a machine can elaborate on it to increase the probability of selecting relevant documents that would not otherwise have been selected finally the paper suggests an interpretation of the whole library problem as one where the request is considered as a clue on the basis of which the library system makes a concatenated statistical inference in order to provide as an output an ordered list of those documents which most probably satisfy the information needs of the user
CISI	is automatic classification a reasonable application of statistical analysis of text the statistical approach to the analysis of document collections and retrieval therefrom has proceeded along two main lines associative machine searching and automatic classification the former approach has been favored because of the tendency of people in the computer field to strive for new methods of dealing with the literature  methods which do not resemble those of traditional libraries but automatic classification study also has been thriving some of the reasons for this are discussed the crucial question of the quality of automatic classification is treated at considerable length and empirical data are introduced to support the hypothesis that classification quality improves as more information about each document is used for input to the classification program six nonjudgmental criteria are used in testing the hypothesis for 100 keyword lists each list representing a document for a series of computer runs in which the number of words per document is increased progressively from 12 to 36 four of the six criteria indicate the hypothesis holds and two point to no effect previous work of this kind has been confined to the range of one through eight words per document finally the future of automatic classification and some of the practical problems to be faced are outlined
CISI	automatic indexing an experimental inquiry this inquiry examines a technique for automatically classifying indexing documents according to their subject content the task in essence is to have a computing machine read a document and on the basis of the occurrence of selected clue words decide to which of many subject categories the document in question belongs this paper describes the design execution and evaluation of a modest experimental study aimed at testing empirically one statistical technique for automatic indexing
CISI	automatic document classification part ii additional experiments this study reports the results of a series of experiments in the techniques of automatic document classification two different classification schedules are compared along with two methods of automatically classifying documents into categories it is concluded that while there is no significant difference in the predictive efficiency between the bayesian and the factor score methods automatic document classification is enhanced by the use of a factor analytically derived classification schedule approximately 55 percent of the documents were automatically and correctly classified
CISI	semantic road maps for literature searchers the retrieval of documented information is one of todays most widespread technical problems affecting almost every large professional group corporation and government bureau because document retrieval is in part an information processing problem much hope for a solution has vested in computers but large fast reliable ones have been around now for five year and people have steadily realized that the over all task of information retrieval is not one of those rote jobs for which digital computers are made to order cataloging and searching are intellectual tasks and have been thought of as rote not because they are menial and straightforward but because they are unpalatable and unwanted many people do like to use their minds yes   but not for plowing through and discarding irrelevant material many people have assumed that this would also be the case in information retrieval accordingly the rush to put computers to work in this area has led primarily to their use as searching instruments and much activity has centered around the design and operation of searching machinery boundary conditions have been assumed such as an ideal searcher who knows what he wants and who knows how to express it in terms understood by the machine and such as ideal correspondence of descriptors to the documents they describe then attention has been focused on optimizing the processes between these boundaries the resulting theories and systems in most cases seem highly adapted to the needs of machine but not adapted to the needs of humans we are after all dealing with the elemental situation of an author talking to a reader   even if by means of a buffer storage which will grow more and more mechanical the basic problem is to increase the mental contact between the reader and the information store so that the reader can proceed unerringly and swiftly to identify and receive the message he is looking for
CISI	morphology of information flow such phrases as information flow may be purely metaphorical or may refer to porterage and storage of physical documents transmission of signals power required for signaling shannons selective information changes in the state of ones personal knowledge propagation of announcements concerning messages social increase of awareness propagation of or reaction to imperatives and so on these matters are distinct and must be distinguished then conditions must be stated under which one can validly speak of and measure the appropriate flow in this paper it is shown that within the field of notification mention and delivery of recorded messages to users there are twenty basic activities formed by choosing triads from the six variables message code channel source destination and designation flow has meaning only when two such triads have two variables in common forming a tetrad then flow or correspondence between any pair of variables is inextricable from a conjugate flow or correspondence between the other pair between any pair of endpoints there are six possibly distinct types of flow according to which two of the remaining four variables are directly used to achieve the flow
CISI	new methods in automatic extracting this paper describes new methods of automatically extracting documents for screening purposes i e the computer selection of sentences having the greatest possible potential for conveying to the reader the substance of the document while previous work has focused on one component of sentence significance namely the presence of high frequency content words key words the methods described here also treat three additional components pragmatic words cue words title and heading words and structural indicators sentence location the research has resulted in an operating system and a research methodology the extracting system is parameterized to control and vary the influence of the above four components the research methodology includes procedures for the compilation of the required dictionaries the setting of the control parameters and the comparative evaluation of the automatic extracts with manually produced extracts the results indicate that the three newly proposed components dominate the frequency component in the production of better extracts key words and phrases automatic extracting automatic abstracting sentence selection document screening sentence significance relevance content words key words pragmatic words cue words title words sentence location research methodology parameterization comparative evaluation
CISI	a mathematical method for analyzing the growth of a scientific discipline the spread of ideas within a scientific community and the spread of infectious disease are both special cases of a general communication process thus a general theory of epidemics can explain the growth of symbolic logic from 1847 to 1962 an epidemic model predicts the rise and fall of particular research areas within symbolic logic a markov chain model of individual movement between research areas indicates that once an individual leaves an area he is not expected to return key words and phrases epidemic model epidemic process theory of epidemics growth of literature history of symbolic logic epidemiology of symbolic logic epidemic curve stochastic models markov chains
CISI	the automatic encoding of chemical structures many methods for the coding of chemical structures have been described in the literature some methods code the compound only partially typical of these are the methods using descriptor codes other methods among which the so called ciphers are prominent code compounds exhaustively all these methods require cerebral effort that is a chemist is needed who must have learned the rules of the code and who must known how to dismember correctly each structure to be coded a disadvantage of code designations of structures is furthermore that they are not generally understood by chemists no advantages accrue to the chemist from knowing how to generate and how to interpret a chemical code codes are needed only for the mechanical manipulation of chemical structures clearly then if the coding of chemical compounds could be accomplished automatically this automatic conversion would relieve the chemist of considerable burden
CISI	rapid structure searches via permuted chemical line notations the wiswesser chemical line notation is an unique and unambiguous method of representing chemical structures by a linear series of letters numbers ampersands and hyphens these symbols are meaningful to chemists familiar with the notation and can be processed by automatic data processing adp equipment the uniqueness of the line notation permits the use of alphanumerically arranged lists of notations for dictionary type searches this ordered arrangement permits the rapid location of a specific compound or a specific class of ring compounds other than benzenoid
CISI	a chemical structure storage and search system developed at du pont as early as 1961 we in the engineering department of du pont recognized the need for a better system for recording chemical structure information for storage and subsequent retrieval we believed that current methods and the then current development of notation systems would not completely serve our chemists long range chemical identification needs accordingly we studied and then developed a chemical structure storage and search system huber gave a good review of the various approaches and applications to use his terminology our system is topological coding our initial investigation led to singling out the following needs for such a system
CISI	the generation of a unique machine description for chemical structures   a technique developed at chemical abstracts service as part of the development of a computer based chemical information system at cas it has been necessary to devise techniques for the registration of drawings of chemical structures a major purpose of the cas registration process is to determine whether a particular structure has already been stored in the system the ability to make this determination makes it possible to utilize a computer to assign to every chemical structure a unique identifying label this identifying label referred to as a registry number is the thread that ties together all information associated with a particular compound throughout the developing cas computer system it is because of this association made possible by the registration process that cas will be able to provide multiple file correlative searches with assurance that all information on file for a particular compound has been located
CISI	esso research experiences with chemical abstracts on microfilm late in 1964 the chemical abstracts service announced that in 1965 it would lease chemical abstracts in microfilm form to subscribers to its current printed abstracts with this move microfilm entered a new stage   use in technical  information work as a publication medium for frequently employed tools rather than for largely archival documents
CISI	rapid structure searches via permuted chemical line notations iii a computer produced index the previous papers in this series have discussed the concept of a index of permuted wiswesser chemical line notations the significance of a quick scan area and simple methods for preparing this type of index for a small index file of compounds up to ca 5000 it has been pointed out that the preparation of a index for a large number of compounds would require the use of a computer this is the subject of this paper
CISI	installation and operation of a registry for chemical compounds since 1958 the chemical abstracts service has been working toward establishing a computer based system for handling chemical information briefly the concept of the cas system consists of sets of special subject files in the following categories 1 physical properties 2 chemical reactivities 3 biochemical activities and 4 applications with the importance of compounds in correlation studies and the need to interrelate compounds and the huge collections of chemical and other data a highly developed subsystem called the registry system for handling compounds must be the first step in the actual operation of an over all computer based service the registry system will include files of compounds interconnected with files of associated data that permit identifying the compounds and retrieving them from the files
CISI	atom by atom typewriter input for computerized storage and retrieval of chemical structures novel features have been added to a paper tape typewriter having a removable typing element a symbol set has been devised which requires only nine characters for typing common chemical structures the typewriter has an uncoded index key which advances the paper without carriage return a companion key back index was provided which directly retracts the paper both have been coded a tape record containing information sufficient for a computer to calculate an atom bond connection table for a chemical structure is obtained by typing the structure in any order solely from the keyboard or by use of the reader with prepunched tapes containing frequently occurring substructures cost was about one fourth that of earlier paper tape chemical typewriters
CISI	isis experiences with asca   a selective dissemination system asca automatic subject citation alert is a commercially available sdi system covering the journal literature the repertoire of questions which asca can utilize includes cited references words from titles authors organizations etc and allows for logical combinations of these questions this paper discusses differences and similarities between citations and words in retrieving and disseminating information the problem of user  system interaction is explored and some techniques for developing effective interest profiles are described although asca is a multi disciplinary system examples from fields like synthetic chemistry and biochemistry are provided
CISI	procedures for converting systematic names of organic compounds into atom bond connection tables simultaneously with its development of a computer based chemical compound registry system chemical abstracts service is devising procedures for automatically converting systematic names of organic compounds into atom  bound connection tables which can be manipulated by computer a study of systematic chemical abstracts ca index names has resulted in a dictionary of word roots used in the names and in step by step procedures for converting names to connection tables statistical studies of nomenclature in ca indexes show that these procedures are applicable not only to current nomenclature but also generally to names in past indexes procedures have been written which are applicable to the majority of names of carbon compounds and the preparation of computer programs is now under way
CISI	a chemical notation and code for computer manipulation this paper describes and specifies the rules for generating a code to represent chemical formulas it may be used either as a notation or for internal manipulation by computer for registration screening and atom by  atom search it is basically a connection table in a concise format which also contains abnormality information relating to specific atoms or relations between atoms the notation produced by these rules unambiguously defines a structure as a connection table but the notation is unique only to a given numbering or citation order of the atoms hence its uniqueness is dependent on the numbering uniqueness of the atoms in the structural formula techniques for the use of the code in registry and substructure search are also discussed
CISI	conversion of wiswesser notation to a connectivity matrix for organic compounds a computer program is described which generates a connectivity matrix using as input an unmodified wiswesser notation this program records the topology of a molecule as a statement of the atoms and their connectivity one symbol is used to represent each atom and this symbol is descriptive of the atom and its bonds the network of a complex molecule is recorded as a series of interruptions in an assumed linear path the application of this matrix to information handling of chemical structures is described in a subsequent paper
CISI	swift computerized storage and retrieval of technical information a unique method of computerized storage and retrieval of technical information is applied in the swift significant word in full title program swift chooses potential keywords from the titles compares the key words with an exclusion word glossary to remove insignificant words and an internal glossary to prevent duplication of terms the keywords may be either a full or fragmented term an option is available to index also by author indexes containing full citations are printed periodically and cumulatively the magnetic tape file is available for computer search through a sort and print program responses to inquiries conducted through the computer program are listed in full citation format
CISI	a chemically oriented information storage and retrieval system ii computer generation of the wiswesser notation of complex polycyclic structures a computer program has been written to generate the canonical wiswesser notation for complex polycyclic structures the program accepts as input the connection between all the ring atoms and then selects the path which conforms to the notation rules the operation of the program is described
CISI	substructure search in the mcc system a monitor system based upon computer produced printed indexes is described in this paper the system is intended to monitor a large scale experiment in file organization for a real time interactive chemical information system it is based upon a topological screen system that ensures the inclusion of every compound atom including h in at least one screen assignment that appears to be responsive to a broad range of query types and that is amenable to random  access techniques the monitor system is also considered in this paper as an independent interim approach toward fulfilling in an effective and economic manner the functional requirements of a small  to medium sized chemical information system thus it could be used to encode and generate structure files to assign search screens and to provide manual substructure search capability via microfilm or hard copy printed indexes
CISI	the idc system for chemical documentation after a decade of systems development firms of the european chemical industry founded a corporation idc to make the chemical journal and patent literature accessible by efficient computer methods a comprehensive and critical review of these methods accommodated to the four most important types of chemical data is given
CISI	operation of du ponts central patent index the central patent index is one of many information centers constituting du ponts information network the development of this index and its relationship with other centers in the network is followed by a description of its operation input storage and search techniques
CISI	the primary journal past present and future the historical role of the primary journal as a social institution of science as well as a communication medium is discussed with particular reference to its function as the official public scientific record and the prime mechanism for rewarding the performance of research the impact of various proposed changes in the role of the journal on these traditional function is also considered and predictions are made as to its possible future state in a more computerized world
CISI	new developments in primary journal publication the form and function of the journal as a medium of communication between scientists that is one scientist talking to another have not changed greatly these past 100 years but during that time the journal has evolved to a highly effective medium for meeting the scientists needs for publication distribution storage and retrieval of scientific information kessler describes the journal as the most successful and ubiquitous carrier of scientific information in the entire history of science and the scientific paper he adds is such a marvelous and commodating invention that we seem to take it for granted and forget that it has form and structure that fit its function
CISI	index chemicus registry system pragmatic approach to substructure chemical retrieval the index chemicus registry system icrs launched in 1968 with the support of a dozen industrial and governmental organizations is now a current operational monthly service subscribers receive magnetic tapes and printouts in which the weekly issues of index chemicus ic have been encoded in wiswesser line notations wln over 13 000 compounds per month are provided in machine language the canonical wln is also provided in alphabetized printouts encoding of over 400 000 new chemical compounds from ic has already been completed including all those reported in 1967 1968 and 1969 since the tapes also include title and other bibliographic information this paper describes the use of supporting software provided for sdi search systems employing word and other searching terms in addition to the wln fragments use of the monthly and annual printouts are illustrated for those searches which do not require computer manipulation
CISI	the multiterm index a new concept in information storage and retrieval an index not only can be a creative communication medium it needs to be in a research and development environment a creative index is achievable if the relationship and association of things and actions one to another can be communicated as a continuous function vis a vis the real world of science and technology a chemist does not think of a chemical for example ethyl alcohol in isolation ethyl alcohol is not merely a word or a term without dimensions to a chemist it is a concept that he associates with or relates to a product a reactant a solvent in a reaction a use a property etc it is within the semantics of his conceptual needs that he would like to use an index to retrieve those documents he needs he wants more than documents however from the index he wants the index to direct him to those documents which are pertinent to his problem he wants the index to help him to generate thoughts and to suggest new combinations he wants the index to help him in terms of his language logic and semantics and through a generic or specific approach whichever occurs to him first he wants the ability to browse among the terms to discover the term that is on the tip of his tongue or recessed in his memory these are the criteria an index must satisfy if it is to be a creative medium of communication
CISI	the gremas system an integral part of the idc system for chemical documentation the genealogical retrieval by magnetic tapes storage gremas system and the potential it offers for searches are described the input and retrieval procedures of the system are explained as well as the integration of the gremas system into the idc system   i e machine generation of the gremas coding from topological input and of the superimposed bit code from the gremas coding
CISI	experience with the mechanized chemical and biological information retrieval system new computer methods have been developed in associations with the drug development programs of the walter reed army institute of research experiences with these systems are recounted special input devices and computer programming have been developed for the input and retrieval of conventional chemical structural diagrams the costs operation and the advantages of this system are discussed associated files of biological properties and inventory control information have been created which are searchable the methods used in creating consolidated listings of selected chemical compounds and associated biological data are discussed
CISI	systems requirements for primary information systems a selected sample of 281 readers of the journal of organic chemistry has been interviewed personally to obtain data on their reading patterns of the november 1968 issue approximately 35 of the individual subscribers to joc had read or looked through the journal within the first seven days of receipt the average reader claims to have read part or all of 14 articles out of the 81 available at least 75 of every one of the 81 articles was read ranging from a low of 0 7 to a high of 10 2 structures or equations rated high as a noted segment of an article in addition to data on amount of reading of the issue respondents were asked about amount of time spent reading other journals read and journals subscribed to correlations have been developed between subject interest as stated by respondent and his actual reading pattern
CISI	design and operation of a computer search center for chemical information the objective of the computer search center csc of the information sciences section of iit research institute iitri is to provide a link between a wide variety of users and the rapidly expanding information resources in machine  readable form because none of the available computer search programs met the criteria of the center and because of the need to handle a variety of data bases new general purpose computer programs were written and a tape format was developed so that a wide variety of data bases can be searched by the same computer program the center was designed to provide current awareness and retrospective search services from both document type and data type computerized data files the desire to develop transferable programs for use at many installations prompted the adoption of the machine independent compiler language pl 1 and the use of ibm 360 series computers the objective of education and training led to the development of a search manual for profile preparation the development of a workbook in modern techniques in chemical information the teaching of a new academic course and the presentation of seminars
CISI	a correlative notation system for nmr data a new linear notation system which denotes carbon in terms of bounds and attached hydrogen s is used to correlate proton groups in organic molecules with chemical shifts the notation system is illustrated with acyclic and cyclic examples and the production of tables of nmr data via computer by proton group vis a vis neighboring groups is demonstrated tables of chemical shifts in ascending order is a valuable by product of the computerized system
CISI	computer generation of wiswesser line notation computer programs developed at the national institutes of health nih produce uncontracted though otherwise canonical wiswesser line notation wln for a fairly broad class of compounds an associated front end allows a chemist to communicate with the programs by drawing structures on a rand tablet the wln generation programs accept connection table input either from a previously existing file or generated from the rand tablet drawing the programs recognize situations which they cannot handle   the output is thus either correct wln or a message by which the programs acknowledge their limitations in general correct wln will be produced for any compound containing not more than one nonbenzene ring work is under way to extend this to polycyclic fused ring systems the philosophy and concepts behind these programs are explained along with the more interesting algorithmic results the role of the wln generation programs in a developing nih chemical information system is briefly discussed the wln programs are written in fortran iv and have been developed on a pdp 10 computer
CISI	interactive searching of chemical files and structural diagram generation from wiswesser line notation an interactive search and retrieval system for weswesser line notation wln has been implemented the system employs bit screens which are useful for filtering a file the user can graphically specify a search request structure and immediately receive graphic information as the result of the search four fortran iv programs were developed to prepare bit screens for wln files input the search request to generate the wln iteratively search the wln bit screen file and generate a two dimensional representation of the chemical structure directly from the wln
CISI	computerized drug information services to compare computerized services in chemistry pharmacology toxicology and clinical medicine of pharmaceutical interest equivalent profiles were run on magnetic tape files of ca condensates cbac excerpta medica medlars and ringdoc the results of these searches which covered individual chemical compounds used in pharmacology and medicine are tabulated overlap of services relative speed of citing references and unique areas of journal coverage
CISI	computer generation of wiswesser line notation ii polyfused perifused and chained ring structure the computer program for the generation of weswesser line notation wln has been extended to include polyfused rings methyl contraction rules chain of two ring systems some perifused rings some chelates and some metallocences salts and ions are also handled but in a different manner than what is normally found multipliers are not used by the program the normal input for the wln generation is an easy input program using a rand tablet however teletype and connection table input can also be used in most cases
CISI	encoding and decoding wln this paper deals with the encoding and decoding of a wiswesser line notation wln this problem so far has been addressed only from the point of human this paper discusses the encoding and decoding with exactness suitable for a computer and is an outgrowth of a computer program now in operation at nih which automatically encodes and decodes wln
CISI	search of ca registry 1 25 million compounds with the topological screens system the tss topological screens system for substructure search was applied to the cas registry file of 1 25 million compounds making it searchable on line the tss screens and the use of the screen indexes are described statistics on screen assignment are provided and the strengths and weaknesses of the system in general and in particular for a large file are discussed
CISI	strategic considerations in the design of a screening system for substructure searches of chemical structure files a major problem in the design of screening systems for substructure searches of chemical structure files is the development of a methodology for selection of an optimal set of structural characteristics to act as screens the set chosen for a particular application will depend on the characteristics of the collection as well as on its size and growth rate a strategy which takes account of the disparate frequencies of the various species of fragments in a data base by use of differential and in part hierarchical levels of description is detailed the distributions of a variety of structural characteristics including bond centered atom centered and ring fragments in a 30 000 compound sample of the chemical abstracts service registry system are summarized implementation of the approach using primarily bond centered fragments by means of simple and highly efficient computer programs is detailed
CISI	chemical abstracts index names for chemical substances in the ninth collective period 1972 1976 index names for chemical substances have been significantly revised by chemical abstracts service cas for volume 76 january june 1972 the first volume of the ninth collective period 1972 1976 and subsequent volumes of chemical abstracts while remaining generally within the framework of iupac and other existing nomenclature rules the most systematic recommended names have been chosen these names are more easily derived from molecular structural diagrams and therefore are more quickly found by index users machine editing of index names and translation of these names into structural representations in the cas computer based information system are also aided by the revisions the index name revisions include i conversion of almost all trivial or author terminology into more systematic names ii simplification of general name selection rules and iii elimination of special treatment for certain classes of substances specific identifiable alloys elementary particles enzymes and mixtures of substances are now indexed like conventional chemical substances difficulties encountered with generation of previous chemical abstracts index names and indexing rules are described and comparisons are made of new and former index names for chemical compounds and substituent radicals
CISI	the ca integrated subject file ii evaluation of alternative data base organizations the relative retrieval performances of the ca integrated subject file caisf ca condensates and a merged file created from these two data bases have been measured retrieval performance is reported in terms of recall and precision values as well as costs the precision and recall retrieval failures   i e irrelevant documents and missed documents   have been analyzed for each data base and characterized according to the five major types of failures index language indexing searching clerical and miscellaneous over all analysis of the performance suggests that an effective data base can be created by augmenting the ca condensates data base with registry numbers and some representation of the caisf general subject concept headings which results in a file approximately half the size of the corresponding caisf data base and is suitable for search using existing retrieval system software
CISI	a chemical search system for a small computer the mechanization of chemical information retrieval systems until now has been limited to those organizations that have access to extensive computer facilities now small low cost computers such as ibms 1130 or decs pdp 11 are available with input output capacities that make them suitable for sdi and retrospective searching on any of the many commercially available data bases such a machine located at the new england research application center nerac is described and the problems of using it for chemical information retrieval are discussed neracs sdi chemical search system is described and an example profile is used to illustrate its capabilities
CISI	use of the iupac notation in computer processing of information on chemical structures a computer operated storage and retrieval system for chemical structures based on the use of the iupac notation has been in operation at shell research limited sittingbourne kent england since 1965 involving a file of nearly 50 000 compounds use of the iupac cipher has proved advantageous as regards speed and cost of both input and searching for most searches scanning of the information explicit in the cipher has proved adequate our computer programs also enable conversion of ciphers into atom  connection tables and generation of fragmentation codes the integrated use of these facilities and their merits relative to other approaches are discussed
CISI	comparative searching of computer data bases methods for retrieval of information on chemical compounds utilizing several computer data bases have been compared to determine scope of data base coverage queries for a single chemical n ethyl   methyl m trifluoromethylphenethylamine fenfluramine and generic chemicals 2 pyrrolidinones were submitted to the services for searching through the recent literature data bases employed included medlars excerpta medica ca condensates cbac ringdoc current abstracts in chemistry and automatic new structure alert ansa preparation of search questions is outlined and comparative results are reported indicating the yield from each data base
CISI	a graph theoretic algorithm for matching chemical structures there are many chemical retrieval systems which process the first type of request efficiently most of these systems are also capable of handling certain fragment requests however the fragments which can be processed are frequently of a restricted nature for example in retrieval systems which are based on linear ciphers only those fragments which are explicit in the cipher are readily detected to allow a completely general specification of fragments it seems inevitable that a detailed atom by atom comparison is required of the query and library structures a technique for making such detailed comparisons is presented in this report this technique is novel in that it avoids the excessive backtracking ad restarting required by other atom by atom matching procedures before giving the details of the proposed algorithm some definitions are reviewed and a brief example is presented to illustrate the over all concepts then the flow diagram of the algorithm is explained in terms of additional examples finally the mechanization of the algorithm for a digital computer is discussed this report is a condensed version of the original which gives a generalization and comprehensive description of the algorithm proofs of convergence and related topics and applications other than chemical retrieval systems
CISI	french national policy for chemical information and the darc system as a potential tool of this policy the incentive and the main lines of french policy on chemical information as well as their implementation are described new governmental bodies have been created aiming at seting up a national network for scientific and technical information among these the cnic centre national dinformation chemique is in charge of the chemical field the darc system is being implemented as a tool of national policy for chemical information an exhaustive chemical data processing system it features topological encoding input and retrieval methods which are described in this paper
CISI	an efficient design for chemical structure searching i the screens a method has been developed for generating efficient screens for chemical structures fragments are generated by an algorithm under control of file statistics the fragments obtained are normalized by weighting their code patterns superimposition of these codes yields the screen codes for the structures
CISI	the chemical abstracts service chemical registry system i general design the chemical abstracts service cas chemical registry system is a computer  based system that uniquely identifies chemical substances on the basis of composition and structure since initial operation in 1964 as a stand alone input storage and retrieval system for structural representations of organic chemical compounds the scope of the cas registry system has steadily increased to include all types of chemical substances and the entire system has been integrated into cas indexing operations the third refinement of this system registry iii which has been in operation for over a year involves major changes in registry recods but no change in the basic algorithmic techniques for registering chemical substances the previous format for listing atoms and bonds has been modified so that each ring system is now separately identified and this ring system identifier is used in the record for each substance that contains that ring these modifications support cas nomenclature derivation and also a computer based structure output system the general design of registry iii which involves a structure record of cyclic and acyclic segments is presented
CISI	an international mass spectral search system msss v a status report the status of msss is described problems and experiences that have been encountered in three years of commmercial operation of this system are reported and discussed
CISI	development and production of chemical titles a current awareness index publication prepared with the aid of a computer the introduction of chemical titles in 1961 marked the first publication produced almost entirely by computers and other data processing equipment the success of this innovation has generated many requests for more information about it with this in mind we hope to encourage other organizations to make use of this technique for dissemination of information by presenting here a history of chemical titles development coupled with a description of its production
CISI	technical abstracting fundamentals ii writing principles and practices abstracts can serve their purpose best only if they are carefully written to transmit important information to readers quickly and accurately this requires knowledge of audience needs habits and desires ability to identify the key facts in the document ability to organize these facts to present them in the order best suited to the audience and ability to write the abstracts clearly concisely and in conformity with the style rules of the medium involved some of these abilities are inborn but all can be learned by study practice and criticism
CISI	patent citation indexing and the notions of novelty similarity and relevance the unique features of the references cited in u s patents are discussed in relation to their use in the patent section of the science citation index which adds a new dimension to patent searching citation indexing provides a new basis for clarifying the concepts of similarity coupling novelty and relevance
CISI	weighted term search a computer program for an inverted coordinate index on magnetic tape ten to 15 years ago much technical literature was accurately indexed according to strict rules of classification today because of the large amount of technical data written it is no longer practical to apply the same rigid indexing procedures we should therefore be concerned with new search techniques which will allow us to handle input at the lower level we are forced to accept this paper describes such a search technique
CISI	articulation in the generation of subject indexes by computer a simple and logical model for the automatic generation of subject indexes from title like phrases is described and its advantages and disadvantages are discussed it is based on recent studies of the structure of articulated subject indexes such as those to chemical abstracts the model employs the prepositions and connectives of phrases of simple structure as articulating points and selects from all possible forms of entries those which lead to optimal organization in an index the technique is illustrated with part of an index to a recent abstracting journal the wide variety of controls which can be exerted by the indexer and the program is discussed
CISI	reading behavior of chemists most discussions about the future design of chemical information systems emphasize the effects of computer speed on composition storage searching and retrieval little attention has been paid to the behavior of the scientist chemist toward the learning process and the role of the literature in that learning process the acs has gained some insight into this behavior and thus urges caution before one leaps to the uncritical conclusion that the literature as now constituted is dead but has not yet fallen over what seems more likely when human behavior patterns are considered is that the new and the old will co exist side by side for several generations and that the systems current emphasis on completeness will be replaced with selective compression
CISI	current information dissemination ideas and practices a detailed description and a tabulated summary of the salient feature of 17 current awareness information services are presented to illustrate various approaches to handling the current information dissemination problem
CISI	critical reviews introductory remarks critical reviews are examined in terms of the quality and quantity of their present production and the measure of their value and utility to scientists in meeting information needs the paper presented the viewpoint of user sponsor author and editor and discuss present problems and possible future solutions
CISI	critical reviews the users point of view scientists are worried about the information explosion and the amount of published literature that could have a significant impact on their work one thing that can help is a condensation and evaluation of the published material this is the task of reviews and without them the other tools for dealing with the information explosion will be inadequate suggestions are made on ways for authors and editors to make their reviews more eccessible and more useful and on the need for better education of users
CISI	a selective current awareness system using engineering indexs plastics data base ii performance the operational performance over a 17 month period of the previously described selective dissemination system is presented of the 21 000 notifications sent to about 20 users 91 were evaluated of these 14 were of document ordered interest 48 were of interest 27 were marginal and 11 were of no interest recall data obtained from about half the users over a period of eight months show the precision  factor recall factor products are generally greater than 0 5 the effect of iterative profile adjustments on precision recall performance is discussed a comparison made with four other sdi systems shows a relatively high level of performance for this system
CISI	user experiences with primary journals on 16 mm microfilm the availability of scientific journals on 16 mm film is a relatively new phenomenon user acceptance of this microfilm application has been greatly improved by loading the file into cartridges and making use of motor driven reader printers this equipment permits rapid searching of the microfilm and adds the convenience of on the spot hard copy prints as needed of prime importance are the economic advantages of these editions since they allow many special libraries to stretch greatly the space available to them for journal housing the economics of this approach are also discussed as are the reactions of the scientists and information personnel who use them
CISI	information transfer limitations of titles of chemical documents some methods of estimating the minimum amounts of information in a document not retrievable through its title are discussed an analysis of the information transferred by different types of keywords is helpful in planning search strategies e g 30 of chemical substances mentioned in journal articles are not discernable in their titles even when broad class names are used as synonyms patents have considerably less informative titles than journal articles in nuclear science report titles are also less informative than those of journal articles but the proportion of reports with completely uninformative titles is now only 10 of the 1957 value titles in chemistry are more informative than those in most other fields but the use of alerting and other services based on titles requires a good understanding of the underlying information transfer principles
CISI	the development cost and impact of a current awareness service in an industrial town the development of a current awareness system in the dow chemical company has resulted in four established services one based on internal information and the other three on chemical abstracts in addition several other services are now being tried or considered the operation of such a service is expensive but the willingness of the user to pay for it and responses to a survey indicate that it is a useful and worthwhile tool to the scientist and engineer the use of such services also has a significant effect on other established information services
CISI	document access long range copies of needed documents will be rapidly and inexpensively supplied to users in libraries or at their desks by querying an electronic network linking document sources central libraries and publishers in the interim local libraries will slowly progress through increased dependence on local holdings of microfilm to development of and dependence on regional national and discipline networks for access to most of the documents desired these developments will depend however on resolution of the copyright problem by mechanisms that will fairly remunerate the copyright owners as background and because radical change is not expected overnight the paper also reviews conventional and sophisticated storage systems including microfilm facsimile and video copyright aspects costs need for speed other user considerations and standards
CISI	an inquiry on new forms of primary publications some of the problems associated with present journal publications practices are discussed these are attributed to the fact that as the literature has expanded the needs of both authors and readers are no longer being met by printing and distributing all of the material accepted to all subscribers a two edition system is proposed with short versions of papers in a broad circulation issue and expanded versions including full details and discussion in library circulation microfilm editions reactions of chemists to such a system are discussed it is recommended that two edition journals be developed in a evolutionary way by increasing use of the acs mcirofilm editions for sections of articles and for supplementary documents to accompany communications
CISI	evaluation of the database ca condensates compared with chemical titles the performance of ca condensates and chemical titles based on analysis of precision and relative recall ct cc for a collection of 46 search profiles was studied over a period of one year special emphasis was laid on the function of the keyword phrases of cc and the users attitude towards literature categories not represented in ct the results are discussed in terms of the value of the systems for danish users seen from users and the documentalists point of view
CISI	evaluation of search time for two computerized information retrieval systems at the university of georgia two statistical models for estimating search time have been developed for the ca condensates data base using the university of georgia text search system graphs showing the effect of data base size and number of search terms on search time are presented comparative timings between the chemical abstracts service search program and the university of georgia search program are made for the ca condensates data base
CISI	user assessment of computer based bibliographic retrieval services the academic users of the bibliographic information dissemination center were surveyed to determine the ways in which the search results were being used the impact which the services had had on professional activities such as research and instruction the interface between the computer based retrieval and the traditional form of library resources and the effect of document overlap between different data bases the survey results indicate that the dissemination services are being used by a large portion of the faculty and the graduate students within the university system of georgia with an average of 3 to 5 people seeing the bibliography from each search question over 97 of the respondees indicated some or substantial contribution to their professional activities with the major contributions being a savings or more efficient use of time and broadened subject coverage the users indicated several changes in library use habits as a result of the computer based searches among them more direct access to the primary literature and increased use of library resources as they had been made aware of new sources and media   e g microforms percentage responses on these and related topics are presented
CISI	an indexing coverage study of toxicological literature a data base of 1873 citations dated 1960 1969 was obtained through an author survey of the members of the society of toxicology coverage was determined by checking the author index through a maximum of three years after publication or through the end of the decade chemical abstracts consistently provided coverage of more than two thirds of the 1960 1967 citations in the data base chemical abstracts biological abstracts index medicus and science citation index each provided coverage of 79 to 85 of the 215 citations dated 1966 and their combined coverage exceeded 98 excerpta medica section iic and chemical biological activities provided 43 and 58 coverage respectively of this same group of 215 citations
CISI	the status of chemical information this report a summary of the status of chemical information processing is the latest in the series prepared by the national academy of sciences  national research council committee on chemical information the period covered is 1969 to the present the user technological developments publications services the federal government academia and industry are the topics reviewed as related to chemical information in addition to present status trends are evaluated problems are stated and recommendations for action by appropriate bodies are included
CISI	evaluation of an sdi service based on the index chemicus registry system the index chemicus registry system icrs is the machine readable equivalent of current abstracts in chemistry index chemicus cac ic in an earlier paper we described the development of an experimental selective dissemination of information sdi service based on these tapes a detailed description of the techniques of profile construction for searching a wiswesser line notation wln structure file is given in this earlier paper the present paper describes the evaluation of the sdi service in terms both of quantitative measures of retrieval performance coverage and currency and also of user reactions to the service as expressed in their replies to a questionnaire failure analysis techniques were used to identify the reasons for retrieval failures and possible methods for improving retrieval performance a fuller description of the evaluation has been published in report form
CISI	computer search center statistics on users and data bases statistics gathered over five years of operation by iit research institutes computer search center are summarized for profile terms and lists use of truncation modes use of logic operators some characteristics of ca condensates etc
CISI	profiling the key to successful information retrieval a major tool employed to enter an information source is the search profile the development of an adequate profile depends upon the aids supplied by the data bases these aids vary in their content and depth and their proper use is essential for relevant information retrieval the data bases examined are ca condensates index medicus and ba data bases several searches are presented with a study of their comparative profiles
CISI	on line searching of computer data bases the research library of rohm and haas company has been searching a variety of bibliographic data bases on line for over one year a summary of our experiences and the merits of on line searching is presented a conference call technique for driving a remote slave terminal is described
CISI	journals most cited by chemists and chemical engineers the purpose of this paper is to present up to date material to indicate some of the changes that have taken place during and since world war ii for purposes of comparison the work of patterson and sheppard is represented in abbreviated form in tables 1 and 2 the results of our own study are presented as tables 3 and 4 the reader can draw several obvious conclusions about half of all the citations in tables 3 and 4 are to papers published in the 1950s this in part reflects the present highly vigorous state of chemical investigation and its rapid expansion in recent years another striking fact is that in the journal of the american chemical society 39 5 of the citations are to previous work published in the journal itself in industrial and engineering chemistry the percentage of self citations is 21 3 to some extent this may result from the fact that writers who habitually publish in a particular journal tend to cite their own work however it seems to reflect to a greater degree the dominance of these journals in their respective fields more than 38 of the citations in industrial and engineering chemistry are to various american chemical society publications in the journal of the american chemical society more than 45 of the citations are to society publications
CISI	overview of the nas nrc conference on large data bases in 1971 the committee on chemical information of the national academy of sciences national research council recognized the problem of large data bases and accordingly created a subcommittee to investigate the problem and its impact on chemical information the first task of the large data base subcommittee was to survey organizations that generate and or process large data bases giering has indicated several different ways in which one can view a data base as being large it can be large in terms of having a large number of entries or records or bibliographic references it can be large in the sense of having a large number of fields or data elements which implies a degree of complexity it can be thought of as large in the sense of having a large number of searchable or selectable elements and it also can be large in the most readily understandable sense of having a large number of characters in storage
CISI	the large data base file structure dilemma this paper first presents a brief tutorial on the principal random file organization methods for handling two major applications   transaction oriented systems and information storage and retrieval systems it then addresses a particular large data base dilemma not satisfactorily resolved by any of these methods and which is currently under active investigation two approaches to a solution are described one is called the hybrid inverted list the other is based upon an old technique called super imposed coding the former has been implemented and has recently been installed in an operational system some statistics related to file characteristics in this application are provided but operational cost and performance statistics are not yet available
CISI	substructure searching of computer readable chemical abstracts service ninth collective index nomenclature files the increasing availability of computer readable files of chemical nomenclature and of programs for text searching has led to the development of methods for performing substructure searches in which ca nomenclature terms are used as search terms substructure searches on ca index nomenclature can often result in very high recall relative to topological searches as is shown by experimental results achieved on a variety of searches many data bases which contain ca index nomenclature also contain nonsubstance data thus searching of substance and nonsubstance data can often be done within a single search of a file with both high recall and relevancy profile construction aids prepared by cas make it possible for persons without sophisticated nomenclature backgrounds to construct nomenclature profiles for many questions
CISI	a rapid generalized minicomputer text search system incorporating algebraic entry of boolean strategies this paper presents a rapid and efficient generalized minicomputer text searching system the system has been applied to chemical condensates and enjoys search speeds comparable to services operating on large computer systems complete boolean algebraic search strategy expressions may be used as direct entries and all forms of transaction are automatically processed benchmark search speeds and results are presented for realistic profiles serving varied research groups in a major university chemistry department
CISI	searching ca condensates on line vs the ca keyword indexes a study was conducted to compare the comprehensiveness of searches performed using systems development corporations sdc chemcon data base and keyword indexes of chemical abstracts it was concluded that in most cases a computer search yielded at least as many relevant references as did a manual search however in the case of very general search questions results from manual searches were much more satisfactory
CISI	searching chemical abstracts vs ca condensates as of march 1975 as much as four and one half years of chemical abstracts indexes and on line accessible chemical abstracts condensates can be compared although combined searches of both data bases are the most effective examples are shown in which it is more practical and efficient to search ca condensates chemcon and chem7071 the on line versions of ca condensates loaded at system development corp sdc are compared with ca indexes
CISI	searching the chemical abstracts condensates data base via two on line systems a comparison of the most used features of system development corporations orbit and lockheeds dialog systems is made especially in reference to conducting searchers of chemical abstracts condensates many of the operations are similar in nature however the capabilities are sufficiently different that an experienced searcher can select the system which gives the best results
CISI	a survey of the use of on line computer based scientific search services by academic libraries to explore their use of on line computer based bibliographic search services a one page questionnaire was sent to 100 academic libraries in the united states having separate departmental chemistry or science libraries an attempt was made to determine the background training of the persons performing the searches who the end users were the growth trend the funding the data bases used and the value to the users of the 73 replies 49 3 indicated use of such services while 24 6 were planning to use them primarily by faculty and graduate students of those reporting 83 3 used searchers with a background in library or information science 47 2 had a background in scientific discipline two or more on line services were used by 72 2 a majority of respondents stated that the use paid all expenses or a portion of the expenses the searches met the needs of the use most of the time in 83 3 of the cases and all of the time in 5 4
CISI	semiconductor journals using an on line literature searching system the number of papers in many journals dealing with semiconductors was determined the journals are ranked by the percentage of their contents devoted to semiconductors and by the total number of semiconductors papers are published only four journals devote over half of their contents to semiconductors papers approximately half of the 19 646 papers which were found in 91 journals appeared in eight journals
CISI	a fuzzy set theoretic interpretation of linguistic hedges a basic idea suggested in this paper is that a linguistic hedge such as very more or less much essentially slightly etc may be viewed as an operator which acts on the fuzzy set representing the meaning of its operand for example in the case of the composite term very tall man the operator very acts on the fuzzy meaning of the term tall man to represent a hedge as an operator it is convenient to define several elementary operations on fuzzy sets from which more complicated operations may be built up by combination or composition in this way an approximate representation for a hedge can be expressed in terms of such operations as complementation intersection concentration dilation contrast intensification fuzzification accentuation etc two categories of hedges are considered in the case of hedges of type i e g very much more or less slightly etc the hedge can be approximated by an operator acting on a single fuzzy set in the case of hedges of type ii e g technically essentially practically etc the effect of the hedge is more complicated requiring a description of the manner in which the components of its operand are modified if in addition the characterization of a hedge requires a consideration of a metric or proximity relation in the space of its operand then the hedge is said to be of type ip or iip depending on whether it falls into category i or ii the approach is illustrated by constructing operator representations for several relatively simple hedges such as very more or less much slightly etc more complicated hedges whose effect is strongly context dependent require the use of a fuzzy algorithmic mode of characterization which is more qualitative in nature than the approach described in the present paper
CISI	subject indexes and automatic document retrieval index entries from the subject indexes to ca can in general be converted to normal or title like phrases by applying simple tests to the positions of prepositions and conjunctions in the entries other more complex entries can be transformed after somewhat deeper analysis these manipulations are a necessary preliminary step to the use of the subject index language in retrieval a scheme is outlined for automatically compiling and editing subject indexes by transforming descriptive phrases with regular structure and vocabulary these transformations based on the formal structure of language are shown to be admirably suited to computer manipulation
CISI	the law of constant citation for scientific literature in listing the literature concerning the subject of vibrating plates the following law was noticed rj x aj t constant 5x6 where rj is the citation factor for the year j and aj t stands for the total number of articles that have appeared up to and including year j this citation law is based on the remarkable fact that in more than 150 years the mean number of relevant citations per article per year has remained constant viz 2x8 in spite of the fact that after 1950 three times as many articles have been published as in the period before 1950
CISI	the derivation and application of the bradford zipf distribution any statistical regularities found in documentation should be fully exploited to produce estimates or predictions and to save documentalists work but present formulations of the bradford distribution demand penetrating search for peripheral papers and tedious computation in application the present paper shows that the bradford distribution is closely related to the zipf distribution it requires data on only the most productive journals is mathematically simple and amenable to graphical methods if a proposed idea of the completeness of a search is accepted for comparability of results certain conditions which include a specified minimum level of productivity of journals need to be standardized a standard form is suggested it is found however that a modified form of the bradford distribution is required when bradford type collections of journals are merged into large collections when saturation of the most productive journals occurs
CISI	statistical bibliography or bibliometrics the term statistical bibliography seems to have been first used by e wyndham hulme in 1922 when he delivered two lectures as the sandars reader in bibliography at the university of cambridge subsequently the lectures were published as a book although the debt has never been explicitly recognized by means of citations hulme anticipated modern work on the history of science he used the term to mean the illumination of the processes of science and technology by means of counting documents hulme both summarized the results of cole and eales and produced original work on the growth of uk patents relating these to social progress in the uk and on the changes displayed in the international catalogue of scientific literature relating changes in subject and country production of literature to international developments
CISI	the effect of growth on the obsolescence of semiconductor physics literature semiconductor physics literature is studied in order to investigate recent hypotheses relating obsolescence to the growth in periodical literature and the growth in the number of contributing scientists the results indicate that obsolescence remains constant and that the two growth rates are within experimental error of equal magnitude for this subject over a five year period these results are seen to be inconsistent with the assumption that an exponentially growing literature possesses a constant utility
CISI	the ambiguity of bradfords law recent discussion of bradfords law of scatter has been founded on two formulations that are not mathematically equivalent a method of comparing the two formulations against empirical data is developed and the results using four sets of existing data are discussed the results show that one particular formulation is more consistent with the practical situation
CISI	on the inverse relationship of recall and precision it is now ten years since some slight experimental evidence was presented which appeared to support the hypothesis that there was an inverse relationship between recall and precision the idea of this was certainly not new fairthorne had more than implied it in his discussions on obna and abno systems i e only but not all high precision and all but not  only high recall however it was one of the propositions arising from cranfield i which met with strong opposition and was quite rightly attacked in reply to the critical review by swanson i had to agree that the simple hypothesis required modification by the following year test results coming from the experiments by salton and from cranfield ii made further modification necessary and the hypothesis was finally put forward to read as follows within a single system assuming that a sequence of subsearches for a particular question is made in the logical order of expected decreasing precision and the requirements are those stated in the question there is an inverse relationship between recall and precision if the results of a number of different searches are averaged this it will be noted has four qualifications to the basic statement
CISI	source of citations and references for analysis purposes a comparative assessment the uses to which analysis of bibliographical references and citations can be put are categorized five sources of references and citations are identified and their advantages and disadvantages for various purposes assessed and compared comparative studies of different sources are urged
CISI	a test for the separation of relevant and non relevant documents in experimental retrieval collections many retrieval experiments are intended to discover ways of improving performance taking the results obtained with some particular technique as a baseline the fact that substantial alterations to a system often have little or no effect on particular collections is puzzling this may be due to the initially poor separation of relevant and non relevant documents the paper presents a procedure for characterizing this separation for the collection which can be used to show whether proposed modifications of the base system are likely to be useful
CISI	the journal of documentation this paper examines the implications of the findings of evaluative tests regarding the retrieval performance of natural language in various subject fields it suggests parallel investigations into the structure of natural language with particular reference to terminology as used in the different branches of basic science the criteria for defining the terminological consistency of a subject are formulated and a measure suggested for determining the degree of terminological consistency the terminological and information structures of specific disciplines such as chemistry physics botany zoology and geology the circumstances in which terms originate and the efforts made by the international scientific community to standardize the terminology in their respective disciplines   are examined in detail this investigation shows why and how an artificially created scientific language finds it impossible to keep pace with current developments and thus points to the source of natural language
CISI	optimization of library expenditure on biochemical journals in a 1973 paper sengupta analysed references to biochemical journals in an attempt to provide a guide for librarians with a limited budget he not only ranked journals by the absolute number of citations made to 1969 volumes but related the number of citations to the number of papers and even to the number of words in each journal as perhaps a better guide to selection of journals for subscription than position in the ranking list  a similar procedure is adopted in two more recent articles by sengupta on physiology and microbiology journals
CISI	citation analyses as indicators of the use of serials a comparison of ranked title lists produced by citation counting and from use data lists of journals ranked according to number of citations received are frequently used as indicators of usefulness but little research has been carried out to test the validity of this hypothesis on comparing lists of titles of journals ranked by citation counting with lists of the same journals ranked according to frequency of use using data from a survey at the national lending library it was found that the rank order correlation between the two was low this suggestions that ranked lists produced by analyses of citations do not constitute valid guides for journal selection by libraries
CISI	a scientific theory of classification and indexing and its practical application a classification is a theory of the structure of knowledge from a discussion of the nature of truth it is held that scientific knowledge is the only knowledge which can be regarded as true the method of induction from empirical data is therefore applied to the construction of a classification items of knowledge are divided into uniquely definable terms called isolates and the relations between them called operators it is shown that only four basic operators exist expressing appurtenance equivalence reaction and causation using symbols for these operators all subjects can be analysed in a linear form called an analet with the addition of the permissible permutations of such analets formed according to simple rules alphabetical arrangement of the first terms provides a complete logical subject index examples are given and possible difficulties are considered a classification can then be constructed by selection of deductive relations arranged in hierarchical form the nature of possible classifications is discussed it is claimed that such an inductively constructed classification is the only true representation of the structure of knowledge and that these principles provide a simple technique for accurately and fully indexing and classifying any given set of data with complete flexibility
CISI	a new look at reference scattering it was first observed by bradford that for a large collection of journal references on a given subject most of the articles are derived from a small proportion of the total titles bradford listed the journals concerned in order of decreasing productivity and by plotting the logarithms of the cumulative totals of titles against the cumulative totals of relevant articles produced he obtained a straight line similar results have been obtained by many later workers the pattern is illustrated by table i which shows the distribution of references among journal titles obtained by the author during a study of literature usage in the petroleum industry on the basis of these results bradford then formulated a simple mathematical model to describe reference scattering vickery later pointed out that this law of scattering predicted not a straight line but a curve kendall has now provided a more refined statistical explanation of the straight line observed by bradford
CISI	the foreign language problem facing scientists and technologists in the united kingdom   report of a recent survey the foreign language barrier facing british scientists is a function of a the amount and value of foreign scientific literature produced b the linguistic ability of the people wishing to read it and c the availability and effectiveness of translation services to obtain quantitative data on these points the nll has recently conducted a survey amongst scientists and librarians in the united kingdom and the present paper presents the more important results the survey has shown that the language problem is of considerable magnitude and is common to the majority of scientists and technologists the languages creating the most difficulty are russian german and japanese it has also indicated that local translation facilities are not particularly effective and that as far as national facilities are concerned british scientists are largely unaware of existing services which might help them to overcome their difficulties the results of the investigation suggest a number of lines of action which the appropriate authorities might follow the most important would seem to be the publishing of a international index to translations and the creation within the united kingdom of a centralized japanese translation service
CISI	minimum vocabularies in information indexing words have no precision though in information storage and retrieval we are required to act as if they did we have therefore to impose certain arbitrary conditions to reduce the element of personal interpretation meaning must be remove from the indexing stage to that of vocabulary construction vocabularies can be reduced to a minimum first to a core of terms used in specialist science and following russel ultimately to undefined terms symbolic of sense experience basic english has shown similar minimizing to be feasible for a natural language the success of batten cards shown that the principle could be equally applicable to specialist indexing vocabularies
CISI	opening the black box of relevance the purpose of this project was to identify variables thought to affect relevance judgements and conduct a series of laboratory studies to determine the effects of these variables on relevance judgements this paper discusses the variable of implicit use orientations   the particular attitude taken by a subject judge about the intended use of a document one hundred and forty judges rated each of nine abstracts for relevance to several short information requirement statements the some judges then repeated the ratings each adopting assuming one of the fourteen use orientations described to them it was found that the particular use orientation assumed by the judge has a marked effect on relevance judgements it was also found that implicit use orientations can be analysed in terms of their underlying structure and that their study offers the possibility of discovering the conditions under which one person can accurately simulate and use the implicit use orientations of another relevance judgements have been used as a basis of measures designed to evaluate the effectiveness of information retrieval system this judgements have usually been accepted at face value and have not been subjected to critical scrutiny there is reason to believe however that as ordinarily obtained they may be unreliable and sensitive to a number of conditions of measurement that have not been carefully controlled in previous evaluation studies
CISI	current awareness needs of physicists results of an anglo american study an outline of methods and summary of findings of a study of american british and overseas physicists this project was conducted by aslib research department acting for the institution of electrical engineers and the american institute of physics it took place in 1966 the first year of publication of current papers in physics aims were to assess the need for and reactions to this new current awareness journal and suggestions for improvement and to obtain background information on the current awareness requirements of the physics community
CISI	progress in documentation the term obsolescence occurs frequently in the literature of librarianship and information science in numerous papers we are told how most published literature becomes obsolete within a measurable time and that an item receives half the uses it will ever receive half life in a few years obsolescence is however very rarely defined and its validity interest and practical value are often assumed rather than explained before reviewing studies on obsolescence therefore it is necessary to look at the concept and to identify the reasons why it should be of interest
CISI	bradfords law of scattering these authors collected a large number of references to a certain subject and arranged the periodicals in which the references occurred in order of decreasing productivity thus for applied geophysics they found loc cit p 112 1 periodical containing 93 references 1 containing 86 4 containing 16 49 containing 2 and 169 containing only 1 reference they then made cumulative totals for the two sets of figures so that in the t most productive periodicals there occurred in all r references bradford then plotted log t against r and his curves are reproduced as b and c in fig 1 an exactly similar procedure for periodical references borrowed by butterwick resulted in curve a in both a and b after an initial steep rise up to about r 500 the curves approximate to a straight line r a log t b
CISI	a national loan policy for scientific serials elsewhere 1 a survey has been reported of the use of the serials in the science museum library in brief this showed that where the science museum librarys copy of a serial was frequently used this serial was widely held and that the converse was true in fact it appears that the use of the science museums copy of a periodical is a rough measure of the national loan use of library copies
CISI	journal usage versus age of journal the effective planning of technical libraries would be greatly facilitated if there were some theoretical basis which could be used to predict the probable distribution by titles and by age of journal of future journal demand as a first step the author has recently developed a general expression for the distribution among journal titles of large groups of journal references in this present paper a relationship between usage and age of journal is established and the application of this relationship to some library planning problems is illustrated
CISI	student attitudes to the university library a survey at southampton university a good deal is now known about the use made by students of university libraries notably from the surveys carried out by leeds university library in 1957 and 1960 statistics of use however will not by themselves indicate how good a library is whether as a bookstock a building or an administrative department how adequate is the bookstock how fully is it being exploited how important are physical and personal elements these are questions librarians are continually asking themselves but they are also questions readers could be asked directly or indirectly
CISI	keywords and clumps recent work at the cambridge language research unit has been concerned with the development of automatic classification procedures for information retrieval this has taken the form of research into methods of classification of keywords extracted from documents with a view to using the classes found for co ordinate indexing of technical material we cannot claim to have solved this problem because the methods we have been able to develop so far cannot be applied on a sufficiently large scale we have however made enough progress to make us feel that this a fruitful line of research
CISI	tests on abstracts journals the amount of scientific and technical information published annually in the form of journal articles conference papers reports theses patents and books now greatly exceeds in every field of interest the amount which may be scanned by a scientist wishing to keep himself completely up to date in his own subject for a scientist wishing to inform himself of new developments in neighbouring subject fields the problem is even greater consequently either the scientist reconciles himself to the knowledge that he is not aware of all relevant information in his field or he places increasingly more reliance on such bibliographic tools as are available to guide him towards the relevant literature first among such tools is the abstracts journal
CISI	survey of information needs of physicists and chemists scientific research is expensive and the practical application of its results is even more expensive information services are relatively inexpensive and by constantly improving their scope and efficiency and encouraging the scientist to make the best use of them we can minimize duplication and inefficiency in research and development this is the justification for the present survey and for all the work on user needs which has preceded it
CISI	information use studies part 2   comparison of some recent surveys information use studies are vitally necessary in order to complement challenge and sharpen informed intuitive judgements but even the broadest conclusions drawn from such studies need to be examined critically the conclusions or their generality may sometimes be invalidated by special conditions in the survey sample by the environment having been disturbed by the survey by the interpretation given to questions or observations or by the way the data has been analyzed these same factors make direct comparison of results from different surveys difficult and make superficial comparisons misleading some comparisons and conclusions are certainly much less sound than the casual reader might suppose particularly when results have been compressed and taken out of their context in the original survey the difficulty of comparing information use surveys is well illustrated by the copious footnotes used by menzel lieberman and dulchin in order to qualify the significance of the results which they compare
CISI	a computer aided information service for nuclear science and technology the computerized information centre of the european atomic energy community has become operational a survey of its principal characteristics is given and the main problems that arose in the development phase of the system are discussed the euratom thesaurus includes graphic representation of relationships between indexing terms a dual vocabulary allows specific indexing for high relevance and generic indexing for high recall retrieval strategy involves utilization of boolean operators and frequency of occurrence tables recall ration can be determined graphically by a continuous approach method indexing consistency tests show that it pays to use subject specialists users needs are discussed in terms of subject coverage specificity rapidity and presentation the user service comprises retrospective searches on request as well as customer profile service on subscription there are three types of relevance and various ways of bringing system relevance to coincide with user relevance the centres budgetary requirements are low due to circumspect use of its computer an ibm 360 model 40 its aims are centralization of documentation in the nuclear field and international co operation
CISI	student attitudes to the university library a second survey at southampton university in may 1965 a survey into student attitudes to the library of southampton university was carried out by questionnaire with a sample of 322 undergraduates the aim was to assess the effect if any of the considerable measures taken since the 1962 survey uncontrolled factors mainly related to the rapid expansion of the university may however have effected the results it appears that except for social science students there were few improvements in attitudes and use and that seminars had little measurable effect possible explanations for this are offered and the place of reader services in a university library discussed other items covered by the survey include the use of libraries in halls of resinence and of southampton public libraries which in both cases showed a sharp decline since 1962 the number and cost of books bought by undergraduates and their use of libraries in vacations
CISI	the citation characteristics of astronomical research literature the citation characteristic of papers in the monthly notices of the royal astronomical society especially for the years 1963 5 have been examined as a means of studying the usage of astronomical literature in the united kingdom the decrease of usage with age has been investigated and the decay half life determined particular attention has been paid to the immediacy affect and to its possible variation in different sub fields of astronomy the citations have also been separated according to journal of origin as a result of this study a quantitative estimate has been made of the titles and backruns that are required to satisfy a given percentage of the demand for astronomical research literature in the country
CISI	tests on abstracts journals coverage overlap and indexing in a previous paper j doc 20 4 1964 212 35 a series of tests on the coverage overlap and indexing of abstracts journals were described briefly these were carried out by selecting recent comprehensive bibliographies on specific subjects searching the appropriate abstracts journals via the author indexes to determine the number of references given in the bibliography that were abstracted then consulting the subject indexes to try to locate those references which are known to have been abstracted a further eight bibliographies have been studied and the results are reported here our results are presented below in the following form 1 title of bibliography source content number of journal references reports etc 2 abstracts journals consulted 3 coverage and multiple coverage this is a bar chart showing number of references not abstracted those covered once twice and so on 4 coverage by each abstracts journal given as a bar chart the last column showing coverage by all services combined where bar charts are given they show coverages as percentages of the whole bibliography actual numbers of references being shown beneath the appropriate columns 5 taking each abstracts journal separately we show the headings under which references were found in the subject index some references we were unable to locate so there is often an apparent discrepancy with the figures given in 4
CISI	estimates of the number of currently available scientific and technical periodicals published estimates of the number of scientific and technical periodicals currently being published are analyzed a new estimates is put forward based on the experience of the nll in attempting to build up a comprehensive collection of the worlds scientific and technical periodical literature
CISI	the bradford distribution the distribution of references in a collection of pertinent source documents can be described and predicted by the relation f x ln 1 bx ln 1 b where the parameter b is related to the subject field and the completeness of the collection the model is used to predict the reference yield of abstracting journals in a search for thermophysical property data it is used also to explain differences among various literature studies of the past in terms of differences in subject and comprehensiveness of search the model is derived from s c bradfords law of scattering and is called the bradford distribution
CISI	evaluating the economic efficiency of a document retrieval system a retrieval system may be evaluated strictly in terms of user satisfaction operating efficiency or it may be evaluated from the point of view of efficient means of satisfying user requirements economic efficiency when we consider the relationship between operating efficiency and economic efficiency we are faced with a whole series of possible trade offs there may be several alternative paths we can follow in order to serve user needs the problem is to determine the most economical path to follow pay off factors break even points and diminishing returns must be taken into consideration this paper considers some of these factors in relation to various parts of the complete retrieval system the acquisition subsystem the indexing subsystem the index language the searching subsystem and the equipment subsystem
CISI	the measures of information retrieval effectiveness proposed by swets objective comparisons of the effectiveness of ir techniques are needed for development of ir systems the measures proposed by swets which offer important advantages are analyzed and critically discussed modifications of the swets measures designed to increase their generality and to facilitate their interpretation in terms of system variables are proposed
CISI	a study of cross referencing the problem of determining the optimal cross reference structure for a given index and for a given community of users is discussed a ross reference structure is represented as a graph in which the nodes are index terms and the links are relations between index terms in order to clarify the concept of level of cross referencing the characteristics of cross referencing structure are studied some measures of cross reference distributions are suggested as a means of comparing the cross referencing levels of subject indexes types of relations linking the terms of cross references in existing indexes and thesauri are examined the implications of the study for the construction and testing on indexes and thesauri are discussed
CISI	statistics of scientific and technical articles a new estimate of the number of currently published scientific and technical periodicals has been put forward by k p barr of the national lending library it may be of interest to supplement this with some figures on the number and distribution of articles within these periodicals these figures are derived from a survey undertaken at the nll early in 1964
CISI	author versus title a comparative survey of the accuracy of the information which the user brings to the library catalogue details are given of a survey carried out in a large scientific special library on the comparative accuracy of the author and title information which the user brings to the catalogue the sample was restricted to requests for book material the results are analyzed in detail and show the title to be more accurate some suggestions are made for extending this type of survey
CISI	documentation notes i would suggest three possible reasons for the constant average number of references per article firstly on average articles more than fifteen years old rarely get cited as they are rendered obsolete by the rate of advance the net increase per annum of citeable articles is not as large as might otherwise be expected secondly many relatively small specialized subject areas each tending to have its own literature and internal citation practices are hiving off from the classical areas because of the specialized nature of modern science thirdly it seems that the building blocks of an article can on average be adequately specified regardless of the volume of published information by reference to about eleven items of the prior art relating to the main theme associated concepts and methods and general background
CISI	the parametric description of retrieval tests part i the basic parameters some parameters and techniques in use for describing the results of tests on ir systems are analysed several considerations outside the score of the usual 2x2 table are relevant to the choice of parameters in particular a variable which produces a performance curve of a system corresponds to an extension of the 2x2 table also the statistical relationships between parameters are all important it is considered that precision is not such a useful measure of performance in conjunction with recall as fallout a more powerful alternative to cleverdons inevitable inverse relationship between recall and precision is proposed and justified namely that the recall fallout graph is convex
CISI	documentation notes a recent article by kozachkov and khursin entitled the basic probability distribution in information flow systems describes the fundamental similarity of a number of known statistical regularities in the flow of information they propose a basic model called the hyperbolic ladder and relate it in particular to work in linguistics by zipf in documentation by bradford and in the science of science by lotka the purpose of this note is to speculate further on the relevance of zipfs law in librarianship
CISI	the complete bradford   zipf bibliograph this technical note summarizes the outcome of recent analyses of empirical data which have enabled the general form of the bradford zipf distribution to be elucidated
CISI	the use of social science periodical literature the paper presents the results of a survey of the use of social science periodicals carried out at the national lending library during a period of four weeks in 1968 three quarters of the requests came from universities and industrial organizations and over 90 of the requests were for english language publications over a fifth of the requests were for seventeen titles there were marked variations in the subject matter requested by different types of organizations and although the overall half life of the literature proved to be 3 1 2 years this figure varied considerably from one subject to another concerning the sources of references it was discovered that compared with scientists and technologists social scientists make relatively little use of abstracting and indexing publications appendixes include a copy of the questionnaire used in the survey a list of title requested six or more times and a list of abstracting and indexing publications cited five or more times as sources of references
CISI	social science literature use in the uk as indicated by citations a sample of citations made in 1965 united kingdom social science literature has been analyzed according to subject bibliographic form country of origin language and date and comparisons made with citations from science and technology literature the relative size of the outputs of and demands for literature in these fields are estimated and the subject distribution of citation within social science the interrelations between source and cited subject are discussed use as indicated by citation is compared with use measured by loan demand on the national lending library
CISI	computer indexing of medical articles   project medico an automatic indexing method is described in which index tags for documents are generated by the computer the computer scans the text of periodical articles and automatically assigns to them index terms with their respective weights on the basis of explicitly defined text characteristics a machine file of document references with their associated index terms is automatically produced which can be searched on a co ordinate basis for the retrieval of specified drug related information
CISI	progress in documentation empirical hyperbolic distributions bradford zipf mandelbrot for bibliometric description and prediction since 1960 and especially during the past three years many papers have appeared about particular manifestations and applications of a certain class of empirical laws to a field that may be labelled conveniently bibliometrics this term resuscitated by alan pritchard see page 348 denotes in my paraphrase quantitative treatment of the properties of recorded discourse and behaviour appertaining to it in this field the law cited is usually that named after bradford or zipf according to whether the interest is in vocabulary or periodical literature or physical access in the rate of diminishing returns or in the cumulative yield from a given input the behaviour is hyperbolic that is the product of fixed powers of the variables is constant this type of behaviour has been observed for a century or so in fields ranging from meteorology to economics and has given rise to many particular explanations appropriate to the particular fields thus it has received many names according to its exponents in both senses of that word
CISI	photocopies v periodicals cost effectiveness in the special library evidence provided by the dainton report indicates that special libraries in the uk are far from fully exploiting the photocopying services provided by the national libraries as these photocopying services are legally obliged to operate at cost they offer significant economies to any special library which exploits them systematically this paper describes a simple graphical method of estimating the savings that can be made or the extended subject coverage that can be obtained at no additional cost by substituting photocopies for relevant papers in the peripheral periodicals relating to any well defined scientific or technical subject though photocopying charges must be realistic the confident exploitation of the national photocopying services depends on the avoidance of arbitrary jumps in photocopying charges
CISI	the half life of periodical literature apparent and real obsolescence the expression half life borrowed from physics has appeared quite frequently in the literature on documentation since 1960 when an article by burton and kebler on the half life of some scientific and technical literatures was published although it had certainly been used previously burton and kebler point out that literature becomes obsolescent rather than disintegrating as in its original meaning so that half life means half the active life and this is commonly understood as meaning the time during which one half of the currently active literature was published numerous studies have been carried out mainly by the analysis of citations to establish obsolescence rates of the literature of different subjects bourne points out that different studies have given widely different results so that many of the half life figures reported are not valid beyond the particular sample of literature or users surveyed certainly they cannot be used as accurate measures for discriminating between different subject fields
CISI	half life the first diagram below gives a schematic view of a subject literature that is growing exponentially with time   the number of items published per year doubles in five years each square of the paper represents a published item the marks on the diagram represent current uses of the literature say citations made or items borrowed this year the inked squares are actual uses the dots are hypothetical uses   those that would occur if every published item had an equal chance of being used in fact every fifth item is dotted
CISI	progress in documentation thirty years or more ago a favoured question in examination papers for librarians was some variation on the theme compare the merits of a classified catalogue and an alphabetical subject catalogue this was a subject which it was possible to write on or to discuss at great length advancing a number of theoretical arguments or opinions expressed by pundits without ever stating a single demonstratable fact when in the early 1950s various people such as taube and mooers proposed new techniques for indexing the reaction from the traditionally minded was such that it appeared there was to be a repetition of all the old arguments in an editorial in american documentation in 1955 perry expressed a viewpoint shared by many others when he wrote cautious and searching evaluation of all experimental results is essential in rating the efficiency of documentation systems may the age old controversies that arose from the conventional concepts of classification not be reborn in the mechanized searching systems of the future there is hope for the avoidance of such errors if we will but regard documentation systems as useful devices the benefits of which must be determined not by polemics but by the intelligent measurement of such benefits in relation to needs and costs the machines of the future can make us free but only if we are willing to subject them and ourselves to the most rigid intellectual discipline
CISI	switching languages for indexing the paper describes some properties of simple interconversion devices which enable material initially subject indexed by a particular indexing system to be made available to other institutions using different indexing languages in such a form as to be readily integrated into their indexes reference is made to the outline intermediate lexicon which is the germinal form of a switching language for the field of information science difficulties and problems in effecting satisfactory information transfer through such an interconversion scheme are explored and suggestions made for the lines upon which further research needs to be undertaken the author was the classification research group representative on the international working party concerned with the intermediate lexicon
CISI	progress in documentation classification is so fundamental and pervasive an activity that care is needed to define its scope when discussing a particular application such as information retrieval retrieval from an information store a library of those items relevant to a request involves locating a particular class describing what we think we want and then if necessary adjusting this class   broadening it to find more material or narrowing it if the initial response proves excessive this implies recognition of the relations between the classes and the whole operation is often referred to neatly as locating and relating assuming that we examine only a limited set of documents those most likely to be relevant the operation is entirely one of classification   the recognition of particular classes and their relations the fact that the instrument we use to assist this operation may display quasi classificatory features e g alphabetical sequence or may consist largely of our own brain box and memory store should not hide this otherwise obvious fact
CISI	the thesaurofacet a multipurpose retrieval language tool a description is given of the english electric thesaurofacet a faceted classification and thesaurus covering engineering and related scientific technical and management subjects a novel feature of the system is the integration of the classification schedules and thesaurus each term appears both in the thesaurus and in the schedules in the schedules the term is displayed in the most appropriate facet and hierarchy the thesaurus supplements this information by indicating alternative hierarchies and other relationships which cut across the classified arrangement the thesaurus also controls word forms and synonyms and acts as the alphabetical index to the class numbers the resulting tool is multipurpose as easily applicable to shelf arrangement and conventional classified card catalogues as to co ordinate indexing and computerized retrieval systems the reasons are given for modifying certain traditional facet techniques including the choice of traditional disciplines for main classes the lack of a built in preferred order and the use in certain instances of enumeration rather than synthesis to express multi term concepts methods of application of the thesaurofacet in pre coordinate and post coordinate systems are discussed and brief account is given of the techniques employed in its compilation
CISI	access and recognition from users data to cataloque entries patterns of searching in library catalogues were analysed using the data from a large survey of the use of three university library and one public library catalogues known item searches were the object of the study success or failure of the search was correlated to degree of correctness and completeness of the searchers information about title and author of the item that he wished to locate factors involved in searching strategies were discussed the double role played by both the title and the author as a way of access to the catalogue and as a means for identifying the right entry was examined
CISI	the growth utility and obsolescence of scientific periodical literature lines recently proposed technique for correcting the apparent half life to allow for the rate of growth of the literature and vickerys critical analysis of the proposal are both further analyzed using the concept of utility and considering the sampling variances involved the paper shows that lines technique is both questionable and impractical and that a further factor   the growth of the number of contributors   needs to be allowed for in vickerys analysis a collaborative empirical investigation is proposed
CISI	udc user profiles as developed for a computer based sdi service in the iron and steel industry extension of the selective dissemination of information system required the adoption of computer based techniques the indexing language adopted is udc and it was necessary to construct user profiles based on the classification profiles have been compiled for individual clients of the service for works within the british steel corporation and for broad fields of activity within the iron and steel industry use of the service has shown that udc provides a satisfactory basis for profile compilation the majority of profiles so far constructed have relevance of over 95 based on user assessment possible future developments in the compilation of the profiles are considered
CISI	feasibility study of a scheme for reconciling thesauri covering a common subject the feasibility is examined of devising a scheme for operating a joint keyword system in a given subject area using several independently compiled thesauri it is suggested that if the individual keywords of each participating thesaurus represent indentifiable concepts and these concepts are given unique code numbers then the code numbers enable the keywords of any participating thesaurus to be converted into the appropriate keywords of any other participant incompatibilities between keywords systems arise from differences in the selection and form of keywords eleven types of incompatibility are identified and a method of reconciliation is proposed for each the types of incompatibility that can arise in a single language include those that arise between one language and another so that a multilingual joint system presents no additional problems
CISI	progress in documentation the term informatics was first advanced formally by the director of viniti a i mikhailov and his colleagues a i chernyi and r s gilyarevskii in their paper informatics   new name for the theory of scientific information published at the end of 1966 an english translation was circularized in the beginning of 1967 as the authors state in this paper they are not the first to use this term and they quote a review by professor j g dorfmann of their own book fundamentals of scientific information in which dorfmann criticizes the use of other terminology such as documentation documentalistics information science and so on their definition is as stated above but they are careful to add the rider that informatics does not investigate the specific content of scientific information only the structure and properties in their paper they also advance definitions for information scientific information scientific information activity information officer and information scientist they have backed up their proposal by changing the title of their own book for its second edition and the title of the information science fascicule of the referativnyi zhurnal which is now called informatiki
CISI	several law relations in science bibliography   a self consistent interpretation several power law relations are found to occur in bibliographic studies of scientific journals articles and citations these can be interpreted in a self consistent manner in terms of growth parameters of articles journals and citations similar models have been proposed earlier in physical biological and behavioral sciences
CISI	automatic indexing using bibliographic citations bibliographic citations attached to technical documents have been used variously to refer to related items in the literature to confer importance to a given piece of writing and to serve as supplementary indications of document content in the present study citations are used directly to identify document content and an attempt is made to evaluate their effectiveness in a retrieval environment it is shown that the use of bibliographic citations in addition to the normal keyword type indicators produces improved retrieval performance and that in some circumstances citations are more effective for retrieval purposes than other more conventional terms and concepts
CISI	the extension on users literature awareness as a measure of retrieval performance and its application to medlars the performance of a retrieval system with a file of only a few hundred references can be measured by assessing the relevance of each reference to each of a number of queries a suitable measure of retrieval performance is then the recall ratio   the fraction of the relevant references that are retrieved by the system when the file is large this method of measuring performance is not practicable and recall cannot be measured although it can be estimated a number of estimation procedures are examined and found unsatisfactory another measure of retrieval performance is the extension ratio which is approximately the ratio of the quantity of known relevant references before and after putting a query to the retrieval system the properties of this measure are examined and it is applied to 315 medlars searches
CISI	free text word retrieval and scientist indexing performance profile and costs comparative performance profiles were determined by two independent scientific information centres for on line retrieval by means of a free text words and b subject indexing codes from a data base of 4 600 descriptions of in going research projects in four broad subject areas altogether thirty nine questions that users had previously asked of the science information exchange sie of the smithsonian institution and that were in the four subjects areas were employed by sie staff scientists and twelve of these were independently used by staff members of the biological science communication project bscp of the george washington university results of the two studies showed average recall values 30 40 higher and relevance values 15 20 higher for subject index code use as compared with text word use advantages and disadvantages of both approaches are discussed
CISI	the use of older literature and its obsolescence terminalogy and parameters for describing the relation between figures for the use of library literature and for its age are discussed unless a correction for growth is applied half life fails a simple test of suitability as do brookess aging and utility factors results based on cumulated data have other important disadvantages relative use per item figures are satisfactory the need to relate terminology more closely to the facts they represent is stressed item consultation decay rate and 50 consultation probability age are suggested and defined in the context of citation studies item citation decay rate and 50 citation probability age are equivalent and avoid similar objections in data from nrlsi item consultation decay rates are only approximately exponential different rates are demonstrated for updating and basic searches for academic and other types of readers and for types of literature for some historical searches negative decay rates were found in the nrlsi and bml
CISI	a single computer based system for both current awareness and retrospective search operating experience with assassin assassin as designed and operated by ici agricultural division provides from a single paper tape input a current awareness service by sdi and a retrospective search both by a weighted term machine search and printed kwoc type indexes programs for producing structured thesauri are part of the package input is in the form of abstracts from both published and internal source the system has operated for more than a year at the agricultural division and is currently in use at five other locations flexibility of the package is demonstrated by the variety of applications this paper outlines the various applications and shows how a single package may be used complete or in part or with modification machine costs are given for the major application the system was designed with the possible input of externally produced machine readable data in mind the intended application of the package in conjunction with tapes such as those of the institute for scientific information source and chemical abstracts condensates is outlined
CISI	a probabilistic search strategy for medlars one technique for searching a co ordinate index is to compare each reference with a boolean expression of index terms this divides the file into retrieved and not retrieved references an alternative is to assign each reference score calculated from its index terms and to retrieve the n highest scoring references in the file this scoring technique has several advantages in theory and it performed slightly better in a retrieval test with n equal to the number of references retrieved by the corresponding boolean search in the test a minimum value of n 10 was used and when less then this number of references matched the boolean search requirement the scoring technique successfully widened the score of the search and retrieved twice as many relevant references as the boolean searches
CISI	measuring readers failure at the shelf this paper is concerned with the availability of books known to be held by the library it outlines a simple survey method whereby readers record the non availability of books which they are looking for the survey has already been installed at four university libraries but the results from only one library are considered here these results show how a librarian can find out the degree of non availability or failure in any particular area of the library the causes of failure and even the particular items which are in heavy demand and not available they also provide information on the degree of co operation by the readers the number of titles failing once twice three times etc the overlap of demand for popular books by different groups of borrowers the waiting time for books that failed the pattern of demand for particular books over a period of time the relationship between failure and recall the correlation of failure from one term to the next and the relative use of books inside and outside the library from the results it was possible to recommend certain changes in library procedure which should have reduced failure and to compare the titles of books failing in the main library with the holdings of a departmental library the time spent on the survey and the total cost of the survey are also given
CISI	a statistical interpretation of term specificity and its application in retrieval the exhaustivity of document descriptions and the specificity of index terms are usually regarded as independent it is suggested that specificity should be interpreted statistically as a function of term use rather than of term meaning the effect on retrieval of variations in term specificity are examined experiments with three test collections showing in particular that frequently occurring terms are required for good overall performance it is argued that terms should be weighted according to collection frequency so that matches on less frequent more specific terms are of greater value than matches on frequent terms results for the test collections show that considerable improvements in performance are obtained with this very simple procedure
CISI	comparative efficiency of searching titles abstracts and terms in a free text data base the choice of the suitable data base for providing an information service is governed by factors of coverage performance and cost the cost of the data base to subscribers is a known quantity and the coverage is decided by the data base producers this paper describes an investigation into the relative performance of the four major chemical abstracts service magnetic tape data base chemical titles ct which contains the titles of citations only chemical abstracts condensates cac which contains titles enriched with keyword phrases chemical biological activities cbac and polymer science and technology post both of which contain full digests in addition to titles the performance was measured in terms of the relative currency of the four data bases on the retrieval efficiency of profiles searched against them fifty questions from industrial and government research organizations were used in the experiment search profiles corresponding to these questions were constructed for searching against each database output was assessed for relevance by users and profile performance figures precision and recall ratios were calculated for each profile the overall retrieval efficiency of profiles searched against data bases containing titles only titles plus keywords and titles plus digests was calculated and these results are presented
CISI	towards automatic profile construction this paper describes part of the chemical abstracts condensate evaluation cac evaluation carried out by the united kingdom chemical information service ukcis the work described was designed to test the feasibility of using automatic or semi automatic methods to replace or reduce the intellectual effort involved in retrieving information from machine readable stores particularly those using natural language
CISI	standard times for information systems a method for data collection and analysis with a view of obtaining a set of standard times for information system operations aslib research department is developing and testing methods for collecting and analyzing data on the time taken to perform certain operations the current state of development of these methods is described data collection is by a self recording diary method completed at the time of performing the operation the major problem is one of identifying describing and analyzing the effect of the various factors which might affect the time first results indicate that it is possible to explain a large proportion of the variations in individual times by taking account of a sufficient number of variables
CISI	measuring readers failure at the shelf in three university libraries this paper continues the reporting of the units work on a method of investigating how often readers fail to find what they are looking for on the shelves why they fail and what particular books they fail to find the method used is a slight modification of the earlier one   readers were asked to record on a slip provided the details of the book or periodical they were looking for or subject area they were looking in their academic status and the date and then to place the slip in an adjoining box fron analysis of these failure slips it was possible to determine the cause of the readers failure the individual book the reader was looking for and the pattern of failure for different groups of volumes a new development was surveys of samples of readers carried out during the fortnight of peak demand answers to these surveys provided information on the effect or failure on a readers work what action he took after failing whether he found adequate substitutes how many books he found by browsing and what proportion of the books he consulted he borrowed some of these answers could be checked by a direct count of the books used in and borrowed from the library the investigations were carried out in three university libraries each with its own characteristic library structure and teaching patterns these differences were reflected in the results obtained it is hoped that the methods of investigation used can be employed by librarians to investigate the effectiveness of some of the services in their own libraries
CISI	the aberrystwyth index languages test reports a laboratory comparision of the effectiveness and efficiency of five index languages in the subject area of library and information science three post co ordinate languages compressed term uncontrolled and hierarchically structured and two pre co ordinate ones hierarchically structures and relational indexing eight test comparisons were made and factors studied were index language specificity and linkage indexing specificity and exhaustivity method of co ordination the precision devices of partitioning and relational operators and the provision of context in the search file full details of the test and retrieval results are presented
CISI	progress in documentation research in user behaviour in university libraries the task of the librarian is to achieve his librarys objectives a simplistic statement perhaps but it is rare that a librarys objectives are defined in any terms other than the broadest   for example to meet the needs of its users in fact the definition of objectives in any service organization is likely to be an iterative process but the explicit commitment to users needs however mystical this concept may be requires the librarian to examine users behaviour as a first step to determining policy since a complete state of the art in user behaviour would fill a substantial book this survey is restricted to drawing together some threads of research of potential application in university libraries methodological problems are not discussed here since these are adequately reviewed elsewhere
CISI	document analysis and linguistic theory in this presentation i shell be concerned with only one aspect of information science and its relation with linguistics namely document analysis document analysis is here understood in following sense the extraction of meaning of documents   in the present case written documents we could define the latter without reference to the usual distinction between scientific literature the object of document analysis in information science and other kinds of texts   historical records myths folklore sacred writings etc indeed one of my theses in that there is little hope of understanding the kind of intellectual operations involved in the analysis of scientific documents or questions pertaining to them other than through a study of textual analysis in general as carried out in many disciplines   history sociology cultural anthropology exegesis etc gardin 1969 for the purpose of this presentation however i shall concentrate on the handling of scientific documents in the first narrower sense and only refer to other categories of texts in so far as they have been submitted to analytical processes of a comparable nature
CISI	studies to compare retrieval using titles with that using index terms sdi from nuclear science abstracts a selective dissemination of information service based on computer scanning of nuclear science abstracts tapes has operated at harwell since october 1968 users interest profiles are constructed using euratom index terms and nsa subject categories assigned to each item in nsa the performance of the mechanized sdi service has been compared with that of the pre existing current awareness service which is based on visual scanning of journals and reports by information staff the visual service was found to be providing an important service of good currency and high precision about 85 to a limited number of users the mechanized service is less selective and of lower precision approximately 50 but can be expanded more readily in order to compare the effectiveness of euratom index terms and words on titles for computer sdi matching an experiment was set up in which sixty users of the mechanized service assessed nsa document notifications which were generated by matching either index terms and subject categories or words in titles and subject categories without being aware of the method of matching over 10 000 document assessments fron six issues of nsa were returned the average precision was 45 6 for index terms and 47 3 for title words index terms retrieved more documents in the ratio 1 13 1 but both systems missed many relevant documents retrieved by the other index terms retrieved only 58 of the relevant documents selected by titles the converse ratio was 51 no significant effects of document types or subject on the relative effectiveness of two matching systems were found but when the results were analyzed by title length it appeared that for titles longer than about 100 characters title words gave recall equal to that of index terms though with a lower precision a detailed study of samples of items found by visual scanning but missed by computer matching or found by one computer method but not by the other was made to identify reasons for failure
CISI	recent growth of the literature of biochemistry and changes in ranking of periodicals the ideas and techniques of physics have been systematically applied to the study of living matter since the 1950s and 1960s as a result a rapid and large increase has taken place in the research activity in this field and biophysics and molecular biology have emerged as important areas of study the consequent enormous growth of literature in the field has created great difficulties in tracking out the significant literature of the subject to cope with this unprecedented growth of literature a ranking list of periodicals in this field has been prepared on the basis of citations in the annual review of biochemistry for 1968 1969 and 1970 this list is expected to reflect the impact of literature on the progress of biochemical knowledge more accurately than the list prepared by henkle in 1938 the present list brings out the predominant position of biochemical research in the total scientific effort today and the increasing bias of cognate disciplines towards biochemical methodologies a method of analysis of the number of citations in relation to size of the journal concerned and average length of the papers published has been developed and applied in this study the analysis yields three parameters which should be useful in assessing the actual scientific interest of a journal in relation to the number of paper published compactness of the information content and the scientific value of the paper in relation to compactness of presentation the results of the present study have been discussed in relation to bradfords law of scattering and an extension of the law has been suggested namely that during phases of rapid and vigorous growth of knowledge in a scientific disciplines articles of interest to that discipline appear in increasing numbers in periodicals distant from that field it is expected that the present ranking list will enable librarians and other professional workers in the field of biochemistry to select journals from the viewpoint of their significance to the active areas or present day biochemical research
CISI	a cost survey of mechanized information systems in the course of the survey covered by this paper cost data were collected by visiting eighteen operational computer based systems in europe and the usa using a structured cost analysis scheme the sample included data base producers and self contained systems that both create and provide services from a data base from the data obtained unit costs have been derived for most operations and the factors contributing to variations in the figures are discussed analysis of the data has shown that costs are affected more significantly by factors such as system management salary variations and productivity of staff than by technical factors such as depth of indexing data preparation methods or computer programming the total operating budgets of most of the systems have also been analysed to show the overall pattern of cost distribution including overheads
CISI	progress in documentation measuring the goodness of library services a general framework for considering quantitative measures the literature of the last few decades reflects a steadily increasing concern with quantitative assessment of libraries and their services this concern is both the result of and a reaction to growing pressures from within and without the library profession to adopt the tools of the management sciences the pressures are generated by many factors including the success of these tools in other fields and their adoption by the organizations supporting libraries the increasingly explicit character of competition for funds at all levels and the complexity and critical nature of decisions on the host of new options being created by technology and by formalization of library networks
CISI	on the specification of term values in automatic indexing the existing practice in automatic indexing is reviewed and it is shown that the standard theories for the specification of term values or weights are not adequate new techniques are introduced for the assignment of weights to index terms based on the characteristics of individual document collections the effectiveness of some of the proposed methods is evaluated
CISI	progress in documentation the development of precis a theoretical and technical history before starting to trace the development of precis to its theoretical beginnings i shall describe the system briefly in its present form this will serve not only as an introduction for those who are not familiar with the system but will also help to explain the relevance of some of the historical sections which follow in which we shall see how a machine produced alphabetical indexing system based on a syntax derived from a study of natural language developed out of research into principles for a new general classification precis or the preserved context indexing system differs in some respects from traditional alphabetical indexes and lists of subject headings like the system developed by coates for the british technology index precis consists essentially of a set of working procedures not a prescribed list of terms or phrases the system is firmly based upon the concept of an open ended vocabulary which means that terms can be admitted into the index at any time as soon as they have been encountered in literature once a term has been admitted its relationships with other terms are handled in two different ways distinguished as the syntactical and the semantic sides of the system
CISI	user evaluation of information retrieval systems while fairthorne may not have been the first person to recognize it certainly for this author fairthorne was the first to make explicit the fundamental problems of information retrieval systems namely the clash between obna and abno only but not all and all but not only although it was not until 1958 that the terms occur in fairthornes writings the concept had been discussed in many meetings of the agard documentation panel and elsewhere originally it was considered that to meet these two requirements it might be necessary to have two separate systems and the test of the uniterm system in 1954 was based on the hypothesis that a marshalling system e g u d c was fundamentally different from a retrieval system e g uniterm while the idea persisted in this form for some time it gradually evolved into the inverse relationship of recall and precision which is to say that while it is possible to obtain of the relevant documents all but not only or alternatively to obtain only but  not all it is not possible to obtain all and only
CISI	the evaluation of information retrieval systems methods of testing systems in practice and in theory are critically reviewed some new theoretical considerations are advanced
CISI	a study of current awareness publications in the neurosciences mailed questionnaires were used to study the use of two printed current awareness devices in specialized areas of the neurosciences one manually prepared and the other a product of medlars the study determined who uses each publication how much for what purpose and with what degree of success a major purpose was to discover how valuable the publications are to users and what impact they have had on their own research or professional practice as well as on their information seeking behaviour comparisons are made between the results for the two publications some conclusions are drawn on information seeking behaviour in the neuroscience community and on requirements for effective current awareness services in this field
CISI	foundation of evaluation the mathematical theory of measurement is used to construct a framework for the evaluation of information retrieval strategies the model arrived at is based on precision and recall after a detailed examination of the kind of conditions the model can be expected to satisfy a plausible measure of effectiveness is derived finally a number of other measures are shown to be special cases of it
CISI	progress in documentation this article reviews the state of the art in automatic indexing that is automatic techniques for analyzing and characterizing documents for manipulating their descriptions in searching and for generating the index language used for these purposes it concentrates on the literature from 1968 to 1973 section i defines the topic and its context sections ii and iii consider work in syntax and semantics respectively in detail section iv comments on indirect indexing section v briefly surveys operating mechanized systems in section vi major experiments in automatic indexing are reviewed and section vii attempts an overall conclusion on the current state of automatic indexing techniques
CISI	the effect of a large scale photocopying service on journal sales the proposition is examined that large scale photocopying such as that practised by the british library lending division affects the sales of journals there is little evidence of a reduction in journal circulation figures in spite of large increases in journal prices which have risen much faster in terms of cost per page than the retail price index university libraries have since the nllst was established devoted an increasingly high proportion of their budgets to journals though recent financial pressures are now forcing cancellation an extensive survey of demand for journals at blld shows a heavy concentration on a relatively small number of titles most of them well established journals widely held by libraries and with large circulations the demand for in print issues of the average journal is small it is concluded in the absence of any evidence to the contrary that economic difficulties experienced by journals publishers and the increased demand on the blld are unrelated though both owe something to the economic pressures on libraries
CISI	the status of practicum in graduate library schools the early schools were dedicated to practical work as a necessary component of every program this fact is heavily documented in numerous commentaries on the time as this century progressed however this pioneer preoccupation came under strong criticism and by the 1930s and in more recent decades an equally strong documentation attacks the earlier curricula now in the 1970s amid the many questions raised about the relevance of contemporary library education there appears to be a revival in the use of field experiences
CISI	a new linear notation system based on combinations of carbon and hydrogen a new linear notation system is described which was designed to have a one to one correspondence with the chemical structures represented by the notations each notation is unique and unambiguous yet simple and compatible with computer input and output characters the symbols used in the notation system denote carbon in terms of bounds and attached hydrogen s the notation system is illustrated with acyclic carbocyclic and heterocyclic examples
CISI	costs of library catalog cards produced by computer production costs of 79 831 cards are analyzed cards were produced by four variants of the columbia harvard yale procedure employing an ibm 870 document writer and an ibm 1401 computer costs per card ranged from 8 8 to 9 8 cents for completed cards
CISI	compression word coding techniques for information retrieval a description and comparison is presented of four compression techniques for word coding having application to information retrieval the emphasis on codes useful in creating directories to large data files it is further shown how differing application objectives lead to differing measures of optimality for codes though compression may be a common quality
CISI	entry title compression code access to machine readable bibliographic files an entry title compression code is proposed which will fulfill the following requirements at the library university of saskatchewan 1 entry title access to marc tapes 2 entry title access to the acquisitions and cataloguing in process file and 3 entry title duplicate order edit within the acquisitions and cataloguing in process file the study which produced the code and applications for the code are discussed
CISI	information requirements in the social sciences some preliminary considerations information requirements in the social sciences are almost entirely unexplored i shall argue that exploration is desirable discuss some of the reasons why this is so attempt an analysis of the factors to be investigated and consider some possible methods of investigation this article is an early by product of the investigation into information requirements of the social sciences being carried out by two researchers under my direction and supported by the office for scientific and technical information it is based on the report on the preliminary stage presented to osti in april 1968
CISI	prospects for a new general classification in traditional classification schemes the universe of knowledge is broken down into self contained disciplines which are further analysed to the point at which a particular concept is decated this leads to problems of a currency keeping the scheme in line with new discoveries b hospitality allowing room for insertion of new subjects c cross classification a concept may be considered in such a way that it fits as logically into one discipline as another machine retrieval is also hampered by the fact that any individual concept is notated differently depending on where in the scheme it appears the approach now considered is from an organized universe of concepts every concept being set down only once in an appropriate vocabulary where it acquires the notation which identifies it wherever it is used it has been found that all the concepts present in any compound subject can be handled as though they belong to one of two basic concept types using either entitles or attributes in classing these concepts are identified and notation is selected from appropriate schedules subjects are then built according to formal rules the final class number incorporating operators which convey the fundamental relationships between concepts fron this viewpoint the rules and operators of the proposed system can be seen as the grammar of an ir language and the schedules of entitles and attributes as its vocabulary
CISI	information services in university libraries development in university libraries in recent years in reader services instruction in library use and subject specialization go only a small way to meeting the problems created by the information explosion reasons why more dynamic and personal information services for scientists and social scientists should be developed include the limitations in researchers present use of libraries and information the preference of users for informal channels of communication increasing pressures on the time of university teachers and problems associated with computer retrieval systems specialist posts of information officer should be created as part of the library services but with functions distinct from those of the librarian difficulties that may arise with their location and operation are discussed the cost of information services in depth is heavy but it may be possible to develop them within the existing budget by a reallocation of funds and staff duties
CISI	the viability of branch libraries a simple model of a two stage hierarchical library system is described the model indicates in terms of user costs and library viability how the branch library should be stocked the most significant factor used in the analysis is shown to be the ratio of the two actual user costs rather than the actual costs themselves it is shown that the viability level of stock provision of the branch library is determined by this ratio
CISI	work study in libraries a brief review of the principal work study techniques is given it is suggested that these techniques are applicable to libraries and librarians and will become increasingly useful as the problems of increased work loads become more severe data concerning standard times and performances would be useful for system design and planning providing such data is put in its proper context and particularly if it is used to improve effectiveness as well as efficiency
CISI	administrative effectiveness times and costs of library operations the kinds of information needed by managing librarians to make correct decisions are considered with emphasis on the value of current data on the exceptional situation management information in a library is of greatest use in comparison either internally or with data from other libraries a simple standard method of recording and costing is urged so that librarians may readily identify procedures requiring improvement development of the present costing method is traced from its original state as a simple management information system based on exception reporting i e reporting the exceptions which occur in any particular survey through a pilot study in a large university library to its full installation in two further university libraries the method of analyzing the raw data is described and examples of the tables are given together with brief background information on the libraries concerned after a note on the limitations of the present costing method and of unit costs in general unit times and costs are given for numerous operations in both the libraries surveyed covering both reader and technical services there is agreement between results of several american studies and those of the present investigation for further comparison the information on times and salaries has been used in conjunction with a standard civil service costing procedure
CISI	subject specialisation in academic libraries some preliminary observations on role conflict and organizational stress the library of the university of east anglia has been organized on the basis of subject specialization a system which the author believes to be applicable to small and medium sized universities a comparison of university structure and university library structure shows how the system can bring about organizational strains and conflict situations in respect of career patterns of senior staff members the need to recognize academic considerations for library promotions is stressed and a case made out for the fullest involvement of all senior library staff in policy making
CISI	graduates in academic libraries a survey of past students of the post  graduate school of librarianship and information studies sheffield university 1964 65   1970 71 the sheffield follow up study revealed that an overwhelming majority of graduates of the post graduate school of librarianship and information science are satisfied with their work and working situations some of the factors relating to job satisfaction dissatisfaction are examined together with job mobility and drop out rates
CISI	a personalized service to academic researchers the experimental information service in the social sciences at the university of bath between 1969 and 1971 bath university library experimented with a personalized information service to social science researchers at the universities of bath and bristol the principal service offered was a manual current awareness service based mainly on the scanning of primary and abstracting journals the service was evaluated by feedback slips returned by clients for each reference notified and by a questionnaire at the end of the experiment the relevance performance was good and few references had been seen before some precision could have been sacrificed to ensure comprehensive recall the whole service was rated highly by nearly all users and considered to be a high priority among the various possible claims on university resources those who had the closest contact with the information officers had the best scores on most aspects evaluated and rated the service most highly some general observations on the place and value of an information service in a university library are given in conclusion
CISI	jesse shera and the theory of bibliography twenty years ago jesse shera suggested that there was a need for a more analytical study of bibliography which might help to bridge library and information services little note was taken of this proposal at the time but developments have since occurred and are here briefly reported it is argued that sheras macrobibliography or social epistemology provides not only a subject for theoretical study but that it will also be needed for the rational design of library and information systems and networks of the near future
CISI	library instruction and the development of the individual the purpose of a university education is defined here as the need to guide the student towards becoming a self directing individual this paper examines this purpose in terms of student needs and the awareness of both academic and library staff psychological principles of learning as applied to this purpose are considered together with the use of audio visual methods the paper ends with a consideration of some present practical constraints and the possibilities for future action
CISI	a book catalog at stanford description of a system for the production of a book catalog for an undergraduate library using an ibm 1401 computer 12k storage 4 tape drives an expanded print chain on the 1403 printer and an 029 card punch for input described are the conversion of cataloging information into machine readable form the machine record produced the computer programs employed and printing of the catalog the catalog issued annually is in three parts an author title catalog a subject catalog and a shelf list cumulative supplements are issued quarterly a central idea in the depiction of entries in the catalog is the abandonment of the main entry concept the alphabetical arrangement of entries is discussed sort keys employed filing order observed symbols employed to alter this order and problems encountered cost factors involved in the preparation of the catalog are summarized
CISI	the development and administration of automated systems in academic libraries the first part of this paper considers three general approaches to the development of an automation program in a large research library the library may decide simply to wait for developments it may attempt to develop a total or integrated system from the start or it may adopt an evolutionary approach leading to an integrated system outside consultants it is suggested will become increasingly important the second part of the paper deals with important elements in any program regardless of the approach these include the building of a capability to do automation work staffing equipment organizational structure selection of projects and costs
CISI	bell laboratories library real time loan system bellrel bell telephone laboratories has established an on line circulation system linking two terminals in each of its three largest libraries to a central computer objectives include improved service through computer pooling of collections immediate reporting on publication availability or a borrowers record automatic reserve follow up reduced labor and increased management information loans returns reserves and many queries are handled in real time input may be keyboard only or combined with card reading to handle all publications with borrower present or absent bellrel is now being used for some 1500 transactions per day
CISI	bibliographic retrieval from bibliographic input the hypothesis and construction of a test a study of problems associated with bibliographic retrieval using unverified input data supplied by requesters a code derived from compression of title and author information to four four character abbreviations each was used for retrieval tests on an ibm 1401 computer retrieval accuracy was 98 67
CISI	marc ii and cobol a description of the machine processing of marc ii records using cobol for an application on the library of congress system 360 30 emphasis is on the manipulation by cobol of highly complex variable length marc records containing variable length fields
CISI	a fast algorithm for automatic classification an economical classification process of order n log n for n elements which does not employ n square procedures conversion proofs are given and possible information retrieval applications are discussed
CISI	library network analysis and planning lib nat a preliminary report on planning for network design undertaken by the reference round table of the texas library association and the state advisory council to library services and construction act title iii texas program necessary components of a network are discussed and network transactions of eighteen dallas area libraries analyzed using a methodology and quantitative measures developed for this project
CISI	the marc sort program describes the characteristics performance and potential of sked sort key edit a generalized computer program for creating sort keys for marc ii records at the users option sked and a modification of the ibm s 360 dos tape sort merge program form the basis for a comprehensive program for arranging catalog by computer
CISI	concept of an on line computerized library catalog a concept for mechanized descriptive cataloging is presented together with four areas of research programs to be undertaken
CISI	teaching with marc tapes a computer based laboratory for library science students to use in class assignments and for independent projects has been developed and used for one year at syracuse university marc pilot project tapes formed the data base different computer programs and various samples of the marc file 48 000 records approx were used for search and retrieval operations data bases programs and seven different class assignments are described and evaluated for their impact on library education in general and individual students and faculty in particular
CISI	the recon pilot project a progress report a synthesis of the progress report submitted by the library of congress to the council on library resources under an officers grant to initiate the recon pilot project that gives an overview of the project and the progress made from august november 1969 in the following areas training selection of material to be converted investigation of input devices and format recognition
CISI	comparisons of lc proofslip and marc tape arrival dates at the university of chicago library a comparison of arrival dates of 5020 lc proofslips and corresponding marc magnetic tape records that four fifths of the marc records were received the same week as or earlier than the proofslips
CISI	standardized costs for automated library systems costs of the automated library systems as currently given in published reports tend to be misleading and confusing it is necessary to have a clear understanding of how they were derived before any comparisons can be made clearly defined costs in terms of time units are more meaningful than straight dollar costs and can be used as one means of comparison among various system designs and as guidelines for the design of new systems
CISI	the recon pilot project a progress report november 1969   april 1970 a synthesis of the second progress report submitted by the library of congress to the council on library resources under a grant for the recon pilot project an overview of the progress made from november 1969 to april 1970 in the following areas production official catalog comparison format recognition research titles microfilming investigation of input devices in addition the status of the tasks assigned to the recon woking task force are briefly described
CISI	an algorithm for variable length proper name compression viable on line search systems require reasonable capabilities to automatically detect and hopefully correct variations between request format and stored format an important requirement is the solution of the problem of matching proper names not only because both input specifications and storage specifications are subject ot error but also because various transliteration schemes exist and can provide variant proper name forms in the same data base this paper reviews several proper name matching schemes and provides an updated version of these schemes which tests out nicely on the proper name equivalence classes of a suburban telephone book an appendix lists the corpus of names used for algorithm test
CISI	recon pilot project a progress report april september 1970 a synopsis of the third progress report on the recon pilot project submitted by the library of congress to the council on library resources an overview is given of the progress made from april through september 1970 in the following areas recon production format recognition research titles microfilming and investigation of input devices in addition the status of the tasks assigned to the recon working task force are briefly described
CISI	monocle a new processing format based on marc ii and some of bnbs elaborations of marc ii it further enlarges marc ii to encompass french cataloging practices and filing arrangements in french catalogs
CISI	scope a cost analysis of an automated serials record system a computerized serials record and control system developed in 1968 69 for the technical information department of pfizer inc is described and subjected to a cost analysis this cost analysis is conducted in the context of an investment decision using the concept of net present value a method not previously used in library literature the cost analysis reveals a positive net present value and a system life break even requirement of seven years at a 10 cost of capital this demonstrates that such an automated system can be economically justifiable in a library of relatively modest size approx 1 100 serial and periodical titles it may be that the break even point in terms of collection size required for successful automation of serial records is smaller than has been assumed to date
CISI	a marc ii   based program for retrieval and dissemination subscriptions to the library of congress marc tapes number approximately sixty the use to which the weekly tapes have been put have been minimal in the area of selective dissemination of information sdi and current awareness this paper reviews work that has been performed on batched retrieval dissemination and provides a description of a highly flexible cooperative sdi system developed by the library university of saskatchewan and the national science library the system will permit searching over all subject areas represented by the english language monographic literature on marc
CISI	an algorithm for compaction of alphanumeric data description of a technique for compressing data to be placed in computer auxiliary storage the technique operates on the principle of taking two alphabetic characters frequently used in combination and replacing them with one unused special character code such one for two replacement has enabled the ilo to achieve a rate of compression of 43 5 on a data base of approximately 40 000 bibliographic records
CISI	title only entries retrieved by use of truncated search keys an experiment testing utility of truncated search keys as inquiry terms in an on line system was performed on a file of 16 792 title only bibliographic entries use of a 3 3 key yields eight or fewer entries 99 0 of the time
CISI	a truncated search key title index an experiment showing that 3 1 1 1 search keys derived from titles are sufficiently specific to be an efficient computerized interactive index to a file of 135 938 marc ii records
CISI	selective dissemination of marc a user evaluation after outlining the terms of reference of an investigation of user reaction to the selective dissemination of marc records a summary of the types of users is given user response is analyzed and interpreted in the light of recent developments at the library of congress implications for the future of sdi of marc in a university setting conclude the paper
CISI	analysis of search key retrieval on a large bibliographic file two research keys 4 5 and 3 3 are analyzed using a probability formula on a bibliographic file of 857 725 records assuming random requests by record permits the creation of a predictive model which more closely approximates the actual behavior of a search and retrieval system as determined by a usage survey
CISI	the shared cataloging system of the ohio college library center development and implementation of an off line catalog card production system and on line shared cataloging system are described in off line production average cost per card for 529 893 catalog cards in finished form and alphabetized for filing was 6 57c an account is given of system design and equipment selection for the on line system file organization and programs are described and the on line cataloging system is discussed the system is easy to use efficient reliable and cost beneficial
CISI	content designators for machine readable records a working paper under the auspices of the international federation of library associations committees on cataloging and mechanization an international working group on content designators was formed to attempt to resolve the differences in the content designators assigned by national agencies to their machine readable bibliographic records all working papers emanating from the ifla working group will be submitted to the international standards organization technical committee 46 subcommittee 4 working group on content designators prior to any attempt to standardize the content designators for the international exchange of bibliographic data in machine readable form it is necessary to agree on certain basic points from which all future work will be derived this first working paper is a statement of 1 the obstacles that presently exist which prevent the effective international interchange of bibliographic data in machine readable form 2 the score of concern for the ifla working group and 3 the definition of terms included in the broader term content designators if an international standard format can be derived it would greatly facilitate the use in this country of machine readable bibliographic records issued by other national agencies it should also contribute significantly to the expansion of marc to other languages by the library of congress
CISI	the new york public library automated book catalog subsystem a comprehensive automated bibliographic control system has been developed by the new york public library this system is unique in its use of an automated authority system and highly sophisticated machine filing algorithms the primary aim was the rigorous control of established forms and their cross reference structure the original impetus for creation of the system and its most highly visible product is a photocomposed book catalog the book catalog subsystem supplies automatic punctuation of condensed entries and contains the ability to produce cumulation supplement book catalogs in installments without loss of control of the cross referencing structure
CISI	file structure for an on line catalog of one million titles a description is given of the file organization and design of an on line catalog suitable for automation of a library of one million books a method of virtual hash addressing allows rapid search of the indexes to the catalog file storage of textual material in a compressed form allows considerable reduction in storage costs
CISI	catalog records retrieved by pesonal author using derived search keys this investigation shows that search keys derived from personal author names possess a sufficient degree of distinctness to be employed in an efficient computerized interactive index to a file marc ii catalog records having 167 745 personal author entries
CISI	comparison of marc serials nsdp and isbd s briefly characterizes and compares the specifications for serial records of the mar serials distribution service the national serials data program and the international standard bibliographic description for serials both data content and where applicable machine format are analyzed
CISI	the ad hoc discussion group on serials data bases its history current position and future the ad hoc discussion group on serials data bases was formed as a result of an informal meeting held during the american library associations conference in las vegas on june 26 1973 those in attendance were primarily interested in the generation and maintenance of machine readable union files of serials this authors involvement in that meeting and the later activities of the group stems from a contract between the national library of canada and york university concerning an investigation of the problems associated with machine readable serials files
CISI	providing bibliograhic services from machine radable data bases   the librarys role libraries will play a key role in providing access to data bases but not by subscribing to tape services and establishing local processing centers as is commonly assumed high costs and the nature of the demand will make this approach unfeasible it is more likely that the librarys reference staff will develop the capability of serving as a broker between the local campus user and the various regional or specialized retail distribution centers which exist or will be established
CISI	bibcon   a general purpose software system for marc based book catalog production the bibcon file management system designed for use on ibm 360 system equipment performs two basic functions 1 it creates marc structured bibliographic records from untagged input data 2 from these records it produces page image output for book catalogs the system accepts data from several different input devices and can produce a variety of output formats by line printer photocomposition or computer output microform com
CISI	impact of national developments on library technical services and public services several recently established national programs are evaluated from the point of view of the practicing librarian it is essential that we be aware of the consequences of adopting these programs and that planners and librarians communicate adequately
CISI	conser an update the purposes of this paper are to explain what the conser project is to answer some of the questions that have been raised concerning it and to make some general comments on the problems associated with this type of project this paper will not attempt to review in detail the history and operational facets of the project since these are available elsewhere
CISI	medlars ii a third generation bibliographic production system medlars ii the replacement for the medlars system used by the national library of medicine over the past decade incorporates a number of major advances in the state of the art for massive information retrieval systems on line access to a number of very large bibliographic files an efficient throughput figure validation and mapping of inputs against authority files and modularity and parametric programming to provide the flexibility needed to support future system enhancements major medlars ii subsystems described are 1 specification maintenance 2 input and release 3 file maintenance 4 retrieval 5 publication production and 6 management reporting the medlars ii retrieval subsystem elhill incorporated the results of the experimental aim twx service
CISI	the washington library networks computerized bibliographic system the washington library network is developing a computer assisted bibliographic system to speed and expand library operations throughout the state features include marc format with all content designators subject and name authority files sorting by lc rules and stringent quality control feature modules will add acquisition accounting and circulation support on line capabilities are currently under development this paper describes the present batch mode cataloging support subsystem its history operation impacts problems costs present developmental efforts toward on line integrated acquisitions and cataloging support are indicated
CISI	state of the nation in networking there is little so ephemeral as a current review in an area so rapidly changing as library networking yet this very characteristic of rapid change makes valid the effort of providing an overview at a point in time the first task then is network definition and description necessary because a large number of library activities have been described as networks and only a limited number are covered here the chapter on library and information networks in volume seven of the annual review of information science and technology provides a normative list of essential characteristics 1 a networks function is to marshal resources to accomplish results beyond the ability of any one of its members 2 a network has developed an organizational design and structure that allows it to establish an identifiable domain 3 it has a base in communications technology
CISI	automated alternatives to card catalogs the current state of planning and implementation the results of a study carried out under the auspices of the council on library resources are described the stated goal of this study was to determine and analyze the current state of planning and implementation for computer generated replacements for the card catalog book catalog microimage catalog on line catalog for large collections 250 000 titles or more and selected smaller libraries less than 250 000 titles that had actually implemented an alternative form of catalog
CISI	com catalog based on oclc records the production of a com catalog using oclc records on magnetic tape is outlined standards developed within the library community as represented in the mark format have made this catalog possible a brief overview of the procedures involved and of the catalog is presented
CISI	serials data control current problems and prospects this paper will describe three areas of current serials activity which are of importance to conventional libraries i would like to do this in general terms eschewing details which only seem to serve to confuse the three areas are l standards what they are what impact they can have what influence they currently are having on serials processing 2 standards setting projects i will attempt to describe and or define the almost incestuous intricacies of the national serials data program nsdp the international serials data system isds and conser conversion of serials 3 code revision activities i will outline the influence that current standards and projects are having on code revision activities my comments are to be considered within the context of conventional libraries primarily one wherein card catalogs still exist and manual processes are the rule
CISI	a comprehensive study based on physics abstracts the documentation research project of the american institute has been engaged for some years in an effort to improve the various systems available for the publication and dissemination of physics literature numerous aspects of the problem have been studied and much information has been obtained from the projects listed in the bibliography which appears on the inside cover of this report studies which resulted in the determination of the indexing requirements of research physicists new methods for the content analysis and indexing of physics research papers and better production methods for journal indexes have formed the backbone of the work which has as its ultimate objective the creation of a reference retrieval system which is adequate for the physicists who will use it
CISI	pattern recognition and structure activity relationship studies computer assisted prediction of antitumor activity in structurally diverse drugs in an experimental mouse brain tumor system this paper reports the application of pattern recognition and substructural analysis to the problem of predicting the antineoplastic activity of 24 test compounds in an experimental mouse brain tumor system based on 138 structurally diverse compounds tested in this tumor system the molecules were represented by three types of substructural fragments the augmented atom the heteropath and the ring fragments of the two pattern recognition methods used to predict the activity of the test compounds the nearest neighbor method predicted 83 correctly while the learning machine method predicted 92 correctly the test structures and the important substructural fragments used in this study are given and the implications of these results are discussed
CISI	the status and needs of medical school libraries in the united states this paper prepared at the request of the national library of medicine is the result of a study of the status and needs of the libraries of 86 medical schools and schools of basic medical sciences which are institutional members of the association of american medical libraries and are approved by the american medical association it is intended to summarize the impact of changing experiments in medical research education and practice on the collections serving housing and staffs of medical school libraries
CISI	the georgia tech librarys microfiche catalog the price gilbert memorial library of the georgia institute of technology has reproduced its entire card catalog on microfiche and is updating this basic file with a bimonthly cumulated supplement produced by the computer output microfiche com process the total catalog has been placed with in appropriate microfiche reader in every academic and research department on campus   thereby taking the chief bibliographic record of the library to the faculty user remote bibliographic access is complemented by a telephone request and delivery service which provides delivery of requested books or photocopies from the library to the faculty member
CISI	the frequency distribution of scientific productivity it would be of interest to determine if possible the part which men of different calibre contribute to the progress of science considering first simple volume of production a count was made of the number of names in the decennial index of chemical abstracts 1907 1916 against which appeared 1 2 3 entries names of firms e g aktiengesellschaft etc were omitted from reckoning since they represent the output not of a single individual but of an unknown number of persons the letters a and b of the alphabet only were covered these were treated both separately and in the aggregate with the results shown in the table and in figures 1 and 2 below
CISI	an experiment in index term frequency this paper presents an experimental study of index term frequency as a factor in retrieval performance the frequency of an index term or its breadth as it is called here is the number of postings made to the term in a given collection the question is asked of index terms assigned to documents which function most effectively in retrieval the most term or popular terms or those which are used relatively infrequently the experiment is a retrieval experiment and uses the cranfield salton data breadth of indexing is varied by nonrandomly deleting terms from documents retrieval output is evaluated using the expected search length measure of retrieval effectiveness as well as the usual precision and recall the wilcoxen test is used to determine the statistical significance of the different indexings the results show that the optimal breadth of indexing is a variable depending on user needs if a few documents are wanted or high precision is desired then narrow terms are more effective than broad ones if on the other hand all or most relevant documents are wanted then broad terms are better an argument however can be made for the quality of narrow terms since when these terms are deleted precision never improves whereas deleting broad terms always results in a higher precision a corollary experiment is carried out to compare two indexings of the same average breadth where one indexing consists of semantically appropriate terms   terms taken from the document title   and the other consists of merely reasonable index terms the result suggest that title term indexing is qualifiedly superior
CISI	design equations for retrieval system based on the swets model swetss theory of information retrieval allows the threads of document weighting formulae probabilistic measures of effectiveness and management theory to be woven into a coherent pattern benefits of the theory are the beginnings of a quantitative description of retrieval languages a clear distinction between retrieval systems and language a recognition that retrieval performance can be tailored to suit individual needs in a systematic way and confirmation that question generality is a pivotal feature of the retrieval process the hypotheses involved are still in need of rigorous experimental testing
CISI	job dimensions and educational needs in librarianship this study was undertaken to meet more fully the demands for improved and expanded training of library personnel especially at the middle and upper levels occasioned by the rapidly changing roles and functions of libraries as they try to adapt to the vast social economic and technological changes currently in progress the rise to a higher level of required skills and competencies   often new   has brought about an urgent need for improved training beyond the first professional degree at the post masters level the basic purpose of this research is curriculum development at the post masters level that will equip the middle  and upper level personnel in libraries for the changes confronting them although it would be possible to restructure the masters program and add the courses that this study shows a need for that alternative has not been pursued for two reasons a fairly stable masters curriculum is widely accepted and institutionalized and more important the new courses are designed for a different group of students   experienced librarians
CISI	shawnee missions on line cataloging system an on line cataloging pilot project for two elementary school is discussed the system components are 2740 terminals upper lower case input ibms faster generalized software package and usual cards labels output reasons for choosing faster software and hardware features operating procedures system performance and costs are detailed future expansion to cataloging 100 000 annual k 12 acquisitions on line circulation retrospective conversion and union book catalogs is set forth
CISI	classification systems the field of documentation originated from the desire of librarians to arrange the document collection by subject areas mono dicraredical classification systems were developed for this purpose which made it possible in each case to find a single clearly defined category for each bibliographic item the development of modern science has brought about two principal changes in the situation first it is no longer enough to simply provide for the retrieval of complete bibliographic items as a unit but rather one tends more and more to request informational details that may be contained in the book second modern knowledge has become too complex and interdependent that it is no longer possible to provide a single well defined category for the books or journal articles
CISI	technical scientific information and the efficient application of science the intense development of science and its immediate application in production is one of the characteristic feelings of our time the growth of the economy now depends more and more on the speed of scientific research one of the main tasks of the five year plan 1971 1975 is to develop in every possible way basic and applied scientific research and to rapidly introduce their results into the national economy the directives of the 24th congress of the cpsu emphasize the need to improve scientific technical information and to guarantee the systematic transfer to interested fields and institutions of information on scientific achievements and progressive experimentation in the areas of technology the organization of production and production management
CISI	the language barrier a study in depth of the place of foreign language materials in the research activity of the academic community this volume presents the results of a detailed study of the place of foreign language materials in university research in the course of our investigation we accumulated a large amount of data on the use of published information and of library services by research workers and academic staff our analyses have necessarily been limited by the specific aims of the project but we have been constantly aware that there are many other possible analyses of the same material for this reason we have endeavoured to include in the appendix as much of this raw data as possible and to provide in the text itself when presenting our own analyses as much detail as possible of the methodology and other background information necessary for any full evaluation
CISI	language and information selected essays on their theory and application at one time or another many authors must have faced the dilemma of whether to gather their articles published on a certain topic and republish them as a collection of essays or whether to rework them into an entirely new book i decided in favor of the first course with regard to the articles i had written during the last fifteen years on language and information in particular on the more technical and applied aspects leaving for some future occasion my papers on the philosophy of language
CISI	language and mind the three chapters of this book are somewhat elaborated versions of three lectures the beckman lectures that i delivered at the university of california at berkeley in january 1967 the first is an attempt to evaluate past contributions to the study of mind that have been been based on research and speculation regarding the nature of language the second is devoted to contemporary developments in linguistics that have a bearing on the study of the mind the third is a highly speculative discussion of directions that the study of language and mind might take in coming years the three lectures then are concerned with the past the present and the future
CISI	development of the county law library do you know that there are 3 071 counties and parishes and 59 county equivalents in the united states making a total of 3 130 do you know that only 39 states have statutory provisions for county law libraries do you know that seven states have no listing for county law libraries in the american association of law libraries 1968 directory of law libraries do you know that los angeles county california not only has the largest county law library collection in the united states but it also has seven branch law libraries these four questions readily point out the simple fact that the growth and development of county law libraries in the united states has been uneven without pattern or standards not only on a state to state basis but on a county  to county basis within a particular state a survey of the 39 state statutes relating to county law libraries reveals that there are no two states that have exactly the same method for the establishment administration financial support or maintenance of a county law library
CISI	no special rules for entry of serials one of the objectives of a library catalog is to enable one to determine what books or publications by an author are in the library establishment of special rules of entry for serial publications which preclude attribution of authorship defeats this objective the present rule 6 of the anglo american cataloging rules are the paris principles are criticized in this regard in the course of this criticism it is shown that the presence of a generic title the presence of the name of a corporate body within the serial publication are not valid criteria for determining authorship of a serial publication furthermore using the form of publication produces unpredictable entries for serials therefore it is proposed that special rules for entry of serials be abolished that a serial be treated like any other work of corporate or personal authorship including compilations and works produced under editorial direction this will have the added benefit of allowing consistent treatment of instances of corporate and personal authorship
CISI	periodicals for the small bio medical and clinical library since the advent of periodical literature in the seventeenth century well over ten thousand journals have been published in the field of bio medicine many of these have ceased publication others are only of local interest still approximately two thousand desirable periodicals in this field are being currently released as research and discovery are recorded in the journal literature the greatest asset of a scientific library is its subscription list and periodical holdings it therefore becomes a major responsibility of such libraries to make this wealth of experimental data available to their readers when funds are limited the selection of a periodical collection that will best serve the most urgent needs of the reader becomes of paramount importance a plan of highly selective purchasing must be adopted to prevent the improper use of funds actual needs of the library must be at hand to carry out such a plan
CISI	libraries and cultural change this work is a contribution to the literature of librarianship and some parts of it may interest a wider audience the chapters consist of a series of introductory explorations into several related fields some of these areas are usually included in curricula for library studies programmes under a title such as the library and the community or the social background to libraries
CISI	libraries of the future this report of research on concepts and problems of libraries of the future records the result of a two year inquiry into the applicability of some of the newer techniques for handling information to what goes at present by the name of library work   i e the operations connected with assembling information in recorded form and of organizing and making it available for use
CISI	libraries at large this book libraries at large is itself one tangible outcome of advisory commission activity representing the combined efforts of duke university the r r bowker company members of the commission and its several study groups and many other diverse individuals within and without the library world the resultant theme is the same one that characterized the work of our commission from the beginning   namely a concern that every individual in our society be provided with library and informational services adequate to his current and emerging needs confronting this goal requires a recognition of inevitable change and we have questioned status quo recognizing at the same time the differing pace and character requisite for the implementation of designs in the adaptability to change the national interest demands simultaneous sympathy with people in pockets of illiteracy and people in the vanguards of intellectual achievement
CISI	libraries and librarianship in the west a brief history this book was written in an attempt to fill a gap if one ignored the major historical resources in other languages which few united states students read notably the handbuch der bibliothekswissenschaft edited by fritz milkau and others 2d ed leipzig harrassowitz 1952 1957 registerband 1965 it was plain that the goodly company of works available did not meet all fundamental needs the most nearly comprehensive treatment was elmer c johnsons a history of libraries in the western world scarecrow 1965 which remains in its second edition scarecrow 1970 solid and attractive reading but continues as announced to cover only libraries its attention to librarianship is very limited numerous important theorists are not even mentioned furthermore the predominant organization by type of library hampers the analysis of crosscurrents between libraries and life and thought particularly the development of the image of the library and librarian the aim here has been to tie it all together in the present offering the west is used conventionally european civilization with its near eastern ancestors and its western hemisphere progeny the limitation is practical to try to cover even the west may prove to be too much for one person to go beyond would be rash yet an understanding of those lands beyond would be most valuable to us all let us hope that someone will try to provide it
CISI	libraries and neighborhood information centers it has been suggested by various librarians concerned with inner city service that the library serve as an informational and interpersonal link between community residents and social agencies the major question is whether it is necessary to add another agency to the already overburdened social service bureaucracy the rationale for envisioning the library in this role is twofold 1 the library has achieved a reputation for impartiality because it provides information on all sides of an issue and is not committed to any particular action program community service or clientele and 2 librarians are specifically trained to locate organize update and disseminate information
CISI	libraries and the organization of knowledge from time to time in the course of its historical development a professional activity enters a new stage this usually takes place as the culmination of a series of modifications to the practice of the art arising out of changes in the social situation in which the profession operates skilled workers sensitive to changing needs alter or refine their practice so that it develops in tune with the progress of society itself descriptive accounts of new or improved methods appear in the literature and from time to time a leading thinker makes a new synthesis by combining these explanations into a system or theory which gives a rational account of what is going on and so prepares the way forward this is what dean jesse h shera has set out to do in this collection of his essays and addresses
CISI	libraries in political science this study undertakes to document the process and the thinking that led leyh to his controversial professional political activities and his widely criticized writings in his later years every effort has been made to present the documentary material and to analyze leyhs reactions to political and psychological pressures without favoring any particular position neither a justification nor a critique of leyhs actions is intended
CISI	on the construction and care of white elephants although catalogue codes and standards have received much attention there has been very little fundamental questioning of cataloguing principles and practice basic questions in need of investigation include whether individual libraries need catalogues of their own stock how far printed bibliographies could serve as a substitute the functions catalogues are serving at present and the actual demands placed on them the nature of users and non users and the possible conflicts between the catalogue needs of librarians and non librarians the psychological factors of approachability and usability whether standardization should over rule local needs whether catalogues should be designed for use by readers at all the functions of printed national catalogues the implications of increased co operation and of the changing functions of libraries what a catalogue entry should contain and how it should be arranged and the possible administrative uses of catalogue data mechanization has made these questions of great urgency
CISI	library and information science abstracts a new service for librarians and documentalists a survey of the events leading to the decision to replace library science abstracts by a new service indicates the arrangement of lisa and how this will differ from lsa gives a brief account of the working routines for the new service
CISI	library research at the university of lancaster reference has been made to work done at the university of lancaster in recent issues of the record this article summarizes past present and possible future activities in this field
CISI	library automation experience methodology and technology of the library as an information system the goal of this book library automation experience methodology and technology of the library as an information system is to provide a perspective of the library functions that have been or might be mechanized or automated an outline of the methodology of the systems approach an overview of the technology available to the library and a projection of the prospects for library automation there is a concern in every library for the proper handling and control of a veritable flood of material and for the prompt and convenient fulfillment of service demands that concern is matched by excitement about the possibilities for effective use of the computers and communications network in many library functions knowledge the librarys stock in trade is being generated at an unprecedented rate and sought after with unprecedented intensity technology the driving force behind the librarys problems and one hope for future solution is being advanced to unprecedented levels
CISI	library automation systems this book is intended as a reasonably comprehensive discussion of library automation systems for the librarian without previous knowledge or experience in the field and for the intelligent layman library automation systems in the context of this work are combinations of electronic data processing machines and appropriate programs and operating procedures organized to work together in carrying out with a minimum of human intervention some well defined library process it is a field that many thoughtful observers feel has reached a certain maturity and so deserves to have its portrait made
CISI	library of congress the book was built on interviews with the librarys middle managers on discussions with working specialists in the various divisions on conversations with and questionnaires sent to out of library users and from my own observations through almost twenty five years in the librarys congressional research service after the text was completed it was read by appropriate people in each department for factual content and ultimately by the staff in the librarians office for their comment at no point was there pressure to change text or conclusions   although there were plenty of good natured suggestions on details and nearly everyone urged a fuller description of his own particular specialty
CISI	isbd s and title main entry for serials the international meeting of cataloguing experts convened in copenhagen in 1969 under the auspices of the ifla committee on uniform cataloguing rules later committee on cataloguing set in motion the first major development in continuation of the success achieved by the paris international conference on cataloguing principles 1961 in the matter of the principles and general rules for entry and heading taking under consideration the study of bibliographical data in national bibliography entries prepared by michael gorman the experts of the copenhagen meeting set up a working group with jack wells as chairman charged with drafting an international standard bibliographic description for monographic publications there was common agreement that the objective was the development of specifications for the necessary data elements their order of presentation and the punctuation to delimit them these specifications should be designed to satisfy the needs of national bibliographies and with whatever judicious trimming might be desirable the needs of the libraries of the entire world it was further agreed that these bibliographic descriptions were to be made quite independently of the heading under which they might appear in listings the working group succeeded in its task and brought forth its provisional isbd m in 1971 the first standard edition was published earlier this year the success of this standard is manifested by the continuing increase in the number of countries that have adopted it
CISI	main entry for serials the nature of serials is such that in both the ala cataloging rules for author and titles entries and the anglo american cataloging rules aacr there are special rules for choice of entry for serials that differ from the rules for monographs while the statement of principles adopted at the international conference on cataloging principles paris principles leaves much room for interpretation and controversy regarding serials it also provides for special rules for choice of entry
CISI	conser cooperative conversion of serials project the final report from the association of research libraries ad hoc committee on machine based serials written in january of this year showed that of the 86 libraries which participated in the committees survey of efforts in the area of machine readable serials files 64 had files containing a total of 1 723 568 titles twenty two libraries reported having no files and one library indicated that it was in the process of converting its file the cost of converting these files is approximately 1 500 000 not to mention the utilization of an incredible amount of duplicate conversion effort
CISI	library catalogs their preservation and maintenance by photographic and automated techniques a study the major conclusions and recommendations of the study which follows are that the catalogs of the research libraries of the new york public library be divided chronologically at the earliest possible date that the present or retrospective public catalog be reproduced photographically in book form that the future or prospective catalogs be produced in a combination of card and book form from a store of machine readable data that a central serial record be created to contain acquisition information cataloging and holdings data and bindery records for all serial publications in the research libraries
CISI	library education an introductional survey social structures have changed more quickly during the last one hundred years than during any other equivalent period in history with these changes have come alternations in the role of institutions of higher education during the centennial year we shall try to measure the need and nature of further change and to evolve ideas that may influence its direction in keeping with this idea the graduate school of library science of the university of illinois felt that this indeed was a time propitious for holding an international conference on education for librarianship the profession as a whole and library education in particular are still quite young but in less than one hundred years we have seen revolutionary changes demands have been made on the worlds libraries and in turn on the schools training personnel for these libraries almost too rapidly for them to satisfy it seemed logical for library education therefore to measure the need and nature of future change and to evolve ideas that may influence its direction
CISI	library education and training the conference on library education and training in developing countries was arranged in order 1 to examine more closely the present facilities curricula and programs for training library workers in the developing countries of the world closest to hawaii those in east and south asia 2 to determine their short  and long range needs for trained library workers and 3 to determine their needs for additional library education and training facilities and for revised curricula in the light of this information the conference proposed to evaluate the assistance given in recent years by american advisors and temporary library school faculty in these countries and then to ascertain the roles that both local library schools and their counterparts in the united states can play in serving the needs for trained library workers in these and other developing countries
CISI	library effectiveness this book is an experiment   in several respects the pressures of rising publication together with the dazzling potentialities of the electronic computer are forcing librarians to think more quantitatively about their libraries than most of them ever have before and simultaneously have aroused the interest of the computer expert and the systems analyst in information storage and retrieval systems of which the library is still the most successful exemplar
CISI	the lending of books to one another by libraries it would add greatly to the usefulness of our reference libraries if an agreement should be made to lend books to each other for short periods of time it happens not unfrequently that some book is called for by a reader or that in looking up the answer to a question a librarian has occasion to use a book which he finds in the catalogue of another library but which does not belong to his own collection the book very likely is one that can be replaced if lost but it would take time to get it through ordinary channels it might be necessary to send abroad for a copy or to wait to pick up one if the book is scarce in such a case it would be a great convenience to be able to borrow a book for a few days
CISI	personal relations between librarians and readers when scholars and persons of high social position come to a library they have confidence enough in regard to the cordiality of their reception to make known their wishes without timidity or reserve modest men in the humbler walks of life and well trained boys and girls need encouragement before they become ready to say freely what they want a hearty reception by a sympathizing friend and the recognition of some one at hand who will listen to inquiries even although he may consider them unimportant make it easy for such persons to ask questions and put them at once on a home footing
CISI	the divided catalog as early as 1905 the divided catalog was being presented as a preferable alternative to the dictionary catalog writing in 1958 dorothy grosser found that the steady stream of papers on the subject began in 1938 she reported 21 articles based on actual experience with the divided catalog a quick check of her list discloses that all divided catalogs are not represented by articles she recorded nine opponents of the divided catalog and six better known members of the profession reserving judgement lyle in his new edition of the administration of the college library considers it safer rather than wiser as in his earlier edition to await further evidence faced at central methodist college library with a dictionary catalog which had outgrown its cabinets and which was to be expanded a survey of catalog user opinion was undertaken to determine if some division of the catalog should be considered some revision of the filing would be needed anyway because of inconsistencies which had crept in largely involving the inter filing of subject and title entries the following questions were asked of all users of the catalog during hours selected at random over several weeks 1 are you looking for a particular book or for books on a particular subject were you looking under author title or subject 2 what is your greatest difficulty in using the catalog 3 how would you feel about having the subject cards in a separate file one hundred persons approximately one tenth of the campus population were questioned 93 per cent felt that they would prefer having subject cards in a separate catalog 5 per cent were opposed and 2 per cent undecided it must be admitted that the prejudice of the person asking may have influenced the way in which the question was answered   a similar survey made in 1954 by the university of toronto showed general support for the dictionary catalog
CISI	the trading stamp mentality a number of trips to the united states to teach in library schools have inculcated in me a variety of views about the present state of american library education they are personal opinions   no more   but they come from one who has seen much that he admires and who believes wholeheartedly that the american spirit includes a firm resolution to change whatever is inefficient or corrupt otherwise 1776 would have no meaning the opinions do not stem directly from my experience in the five accredited schools in which i have taught but are strongly rooted in my general observation of library education practice and my discussions with members of the library profession
CISI	top priority for cataloging in source after a century of public library service and progress public libraries attract less than a third perhaps only a quarter of the adult population either to read and borrow books or to look up information but nearly 60 per cent of the population is over 21 currently a few large city libraries show slight decreases in annual circulation the major measure of their usefulness yet nationally circulation and the informational use of public libraries have in general steadily increased especially in the last decade possibly because the number of public college university and special libraries doubled from 13 676 reported in 1960 to 27 746 in 1968 publishers weekly january 20 1969 and there are more than that many school libraries
CISI	backlog to frontlog a scheme for circulating nonfiction books without the help of the library of congress
CISI	the urban library dilemma the american urban public library is in something of a dilemma relatively secure in the affections of the populace the library is nevertheless frequently threatened by loss of income the threats are cyclical and are associated with the local tax picture which at the present time is notably obscure the abortive attempts earlier this year to reduce appropriations for the libraries in newark and new york received widespread attention both because the libraries are quite visible nationally and because the proposed cuts were preposterously unmistakable in the eye of the politician who must find that tiny bit of safe water between the shoals of economy and those of service the library appears to be expendable ballast to be dumped in heavy weather in 12 years in two city libraries i have seen almost every budget year produce a critical fight to prevent disaster from overtaking the library i think the experience is not uncommon only the most extraordinary efforts keep most urban libraries from going under libraries seldom thrive they survive periods of calm and prosperity are rare for urban public libraries in the richest nation in the world during this era of extraordinary national economic success the paradox invites some critical self analysis
CISI	the library press the deadliest disease afflicting the library press is proliferation the kindest and most conservative estimate i am able to bring myself to make is that there are at least three times as many library periodicals in this country as we can afford or are necessary perhaps the most constructive single thing that could be accomplished would be to persuade at least one in three publishers of a library periodical to cease publication one might reasonably expect that librarians who have done so much public wailing about the publication explosion would be among the chief advocates and practitioners of birth control in the world of print instead we find them cavorting as uninhibitedly in the king size bed of printed procreation as do the denizens of the sodom and gomorrah of science and technology just about every library of any consequence and some of little consequence and almost without exception every group or organization within the loose boundaries of our profession decides virtually at the moment of its birth that it cannot survive without a publication of its own   a newsletter a journal some regular calling card to announce its presence to the world at large
CISI	library education and the public library a major and largely justifiable criticism of library education has always been that it is too closely tied to present practices and that it trains for current service instead of educating for growth and change unfortunately the picture many faculty members have of what todays requirements for public library service are tends to be obsolete graduates are thus doubly handicapped not only do we fail to educate we fail even to provide realistic training at worst we perpetuate the past and train people for tasks that are no longer central to the concerns of public libraries library education like the public library itself will have to accelerate the pace of change or risk the fate of oblivion institutions that can move with the times and maintain a position of relevance to contemporary affairs will survive others will wither away disappear or be replaced by more responsive agencies there is no shortage of prophets of doom for both the public library and for graduate library education but there are plenty of signs of life yet in both an article in the june 13 1968 issue of the reporter called dust gathers on the public library summed up nicely the apparent slow decline and loss of purpose of a once revered institution however the reporter is dead   while the public library lives on
CISI	crisis in library education a battle is currently being waged at the university of maryland school of library and information services its outcome will influence the future of the library profession because of the significance of this controversy this situation at maryland is here brought to the attention of the profession at large last fall a group with funding from the office of education brought into being an educational program which is addressing the professions most critical problems those central to its survival as a viable social institution the library professions need to define and fulfill an important service function in the public arena its failure to make itself relevant to other than middle class interests in the culture and its inavailability to contribute to the alleviation of the severe social economic and other inequalities which exist in the culture and which continue to deprive black americans particularly of even minimal life opportunities
CISI	along the academic way the invitation to apply for this council on library resources fellowship stated as one aim to break administrators loose from their desk to read investigate and reach for broadening experiences that might make them administrate better the application listed seven targets of study in the working context of university research libraries 1 organizational structures 2 management techniques 3 program budgeting 4 use of machines including the computer 5 research collection development 6 non book materials in the library 7 out of  building services
CISI	the philadelphia project the objectives of the research were 1 to determine actual requirements for library resources by elementary and secondary grade students and to evaluate existing library resources in terms both of student needs and national standards and 2 on the basis of this information to outline the respective roles of the school libraries and the public libraries in providing needed resources and in developing joint planning
CISI	library cost analysis a recipe unforgivably time has passed since the days when the librarys patron was the local monarch and cost was no deterrent times passage has replaced the monarch with taxpayers or stockholders and concurrently sensitivity to cost has attained stellar importance the causes for being unaware of costs may stem from a variety of reasons but they cannot in all fairness to the profession belie an inability to perform the simple arithmetic of cost accounting what is suspected is a lack of the few simple ground rules and the logical operations that bind them together in short   a recipe for cost accounting and analysis in the following is outlined one such set of ground rules and their related procedural requirements which have evolved and been applied with success over the past few years it is stressed that since this set represents the findings of one library it may not fully satisfy the specific requirements of your own shop therefore feel free to adopt the ground rules to your immediate requirements with regard to discipline it is pretty much summed up in the six steps and five resource requirements which follow in addition to identifying steps requirements and the mysterious ways of cost analysis these ingredients are blended together in a manner which will be meaningful for your internal operations and may be significant for your librarys future
CISI	the paradoxes of library cooperation the need for libraries to cooperate has long been recognized as countless articles written within the past decade will attest moreover the necessity to combine forces has never been as apparent as it is today because the cost of self sufficiency has become undeniably prohibitive libraries can no longer afford to act as free agents voluntary library cooperation is no natural manifestation of social interaction rhetoric alone is a impotent agent of change in truth cooperative programs succeed only as long as each participant perceives the arrangement as beneficial to his institution
CISI	isbd its origin rationale and implications a proper understanding of the international standard bibliographic description isbd a standard promulgated by the international federation of library associations ifla requires some knowledge of how it came into existence what reasoning prompted its development ad what useful results can be expected from its adoption these matters will be dealt with below hopefully in sufficient detail to provide readers with a basis for teaching a sound evaluation of the effect of this standard when applied to american cataloging practice and in particular to lc cataloging and marc tapes
CISI	isbd standard or secret the controversial isbd will mean radical changes in descriptive cataloging practice if put into operation as planned by the library of congress users of lc catalog cards will require retraining all reference librarians will experience an immediate and continuing demand for explanation of the new catalog cards to users those large public and research libraries with computer based systems will require costly modifications of computer programs yet the isbd international standard bibliographic description is destined to be implemented by the library of congress with the sanction of ala but without even being considered by the recognized standards associations iso ansi to say nothing of the other professional and information industry organizations
CISI	pay libraries user charges the battle lines are being drawn for a great debate over the emotionally and politically charged issue of how library and information services are to be funded in the coming decades most librarians will be on the side of conservatism and democracy favoring the continuation of traditional modes of tax supported public library service with information freely available to all as a matter of right information industry people publishers government officials engineers and even perhaps authors will be on the side of progress and profits advocating a new concept of for profit or pay libraries user charges and information as a salable commodity
CISI	austerity technology and resource sharing research libraries face the future during the last two decades academic libraries in parallel with their parent institutions experienced the greatest period of growth and affluence that they have ever known the watchword was more   more money more books and journals more staff more space and more technology many new research libraries were created and those that already existed experienced unprecedented growth although libraries got more of everything during those years they still could not keep pace with the growth of new fields of research new doctoral programs and the increasing production of books and journals two decades of affluence not only failed to help solve the many problems that were brought on by exponential growth   they exacerbated them
CISI	the view from the tower of babel a funny thing happened on the way to the biggest building boom in library history book collections grew faster than the new space to hold them so when the boom was over the aggregate space problem of academic libraries was a little worse than it was at the beginning during the roughly eight year span of the rise and fall of the boom some 570 new or expanded library buildings sprang up on the campuses of four year and graduate institutions around the nation
CISI	a library management game a report on a research project although the use of games in professional education has become widespread only during the last decade the method has been used in a number of fields for many hundreds of years its origins have been traced to simple war games used in military training when the real thing was either unavailable or too dangerous in more recent times these games have become more and more sophisticated and many now use large electronic computers to handle the complex calculations involved since 1956 when the first well developed management game was introduced the technique has spread rapidly into a wide variety of disciplines and today it is used at all levels of education from primary school classes to courses for experienced men and women one of the main causes of this game explosion has been the rapid development of sophisticated management techniques such as simulation and mathematical modelling which have been made possible by rapid advances in computer technology
CISI	library materials the problem investigated by the research was the development of standards for reading materials that would support the adult new reader in the exercise of his new found skill and build the habit of regular use of the printed word bridging the gap between minimal literacy skills and the reading habit was proposed as essential to the purposes of the library program in helping the reader improve has basic education skills increase his employability and develop his potential as a citizen and gain personal satisfaction in his many adult roles the nature of library materials best designed for this end required study in depth the findings and conclusions derived from the research project provide basic information about the adult new reader and his reading criteria for analysis of reading materials and a bibliography of materials these products of the study constitute a series of reading selection and guidance aids for use by all persons working in this area of service    librarians community workers teachers publishers editors and reading specialists
CISI	library networks the combination of computers and communications technology is a development whose time has come for libraries in the u s and despite missteps and false starts inevitable in adapting the new technology for its use libraries are now rapidly expanding telecommunications networks to serve their need to disseminate ever expanding amounts of information in more effective ways it makes a good deal of sense when one considers that the librarys function is to parcel out information and that information can be forwarded electronically as easily as it can be mailed in fact the logic of library networks is such that everyone is hopping on the bandwagon    consultants systems analysts state agencies and a growing list of manufacturers that includes xerox and international business machines their initial efforts are concentrated on what are basically bookkeeping tasks    in particular the cataloging of new acquisitions the ohio college library center for example provides its customers with entries for their card catalog files and because oclc is the first and most extensive of the networks its approach is being closely copied by the others
CISI	library planning and decision making systems the research project which produced this book concentrated on the problem of the design and development of statistical information systems that would provide quantitative information for effective management of university and large public libraries since there is an inseparable need not only for improved library statistical data systems but also for the above mentioned frameworks for rational planning and decision making we have devoted considerable effort to the development of analytical models that might assist library administrators in making decisions that would maximize the flow of benefits imparted to the communities the library serves some of the results of this model building effort are repored in these pages
CISI	library practice in hospitals according to a national hospital panel survey conducted by the american hospital association in february 1970 4 191 72 percent of the 5 820 community hospitals in the united states operated a library this percentage falls to 60 when only hospitals of less than 100 bed capacity are considered 1 990 libraries in 3 318 hospitals in the 4 191 libraries one or more full time staff members were found in only 1 054 25 percent in even fewer 928 was there supervision of the library by a professional librarian clearly there is a massive job to be done if these libraries are to perform properly their functions of health education and patient care by community hospital we mean the nonfederal short term hospital providing general and selected special services the hospital located at some distance from a large medical center and without teaching and research programs such as a nursing school or internships though the librarians of more sophisticated teaching institutions may well profit from the study of this book it is written primarily for an audience of untrained probably newly employed individuals who find themselves supervising the hospitals library and do not know where to begin
CISI	the crisis in cataloging a wise german librarian has linked the library administrator and the cataloger as working for the common aim of economy in work and cost coupled with better utilization of a librarys resources this aim he thinks is expressed in various kinds of cooperative work of pooling interests and of setting standards it is to be developed prudently he says with the objectives setting limitations in such a way that more values will not be destroyed than are created this ideal he set out in a chapter entitled tasks for the future there was a time and not so very far back when the library administrator and the cataloger worked side by side in the more immediate past however the two have become separated so that their closer collaboration does need to be set down as a task for the future the immediate future at that many new problems of administration have served to busy the administrator and most catalogers have had more work than enough with the result that administrators have come to know less and less of cataloging and catalogers have come to know less and less about general library administration the situation now is that the administrator will be forced to pay more attention to cataloging because it has become a major problem field
CISI	the historical background of departmental and collegiate libraries in spite of the great volume of material dealing with departmental and collegiate libraries that has appeared in library periodicals and books on university and college library administration there has been relatively little original thought on the subject and virtually no historical treatment to provide an adequate background for solution of problems which have their roots in a former generation most of the literature has been either repetition of the old arguments for and against this type of library organization or statements of how this or that institution has faced its peculiar problems except for contemporary accounts of early american scholars describing the attempts to transplant the german seminar library to american soil and reports on a few large university libraries there is no account of the conditions which brought about and for many years invigorated the departmental system an evaluation of trends in the history of departmental libraries over the last three quarters of a century should prove to be a valuable supplement to other information in the hands of surveyors and administrators who are interested in abolishing establishing continuing or amalgamating departmental libraries in a given institution
CISI	characteristics of the research literature used by chemists and physicists in the united states the increasing growth and complexities of research libraries are natural consequences of the growth of knowledge and the increasing complexity of knowledge librarians have tried to amass more and more knowledge in the form of books for the benefit of the diverse interests of their clienteles their success in this activity has been reflected in the increasing difficulties of identifying satisfactorily what they have the processes of cataloging classifying and related technical routines have become increasingly complex and expensive the processes are of such a nature that the cost for adding each new item to a large library is on the average potentially if not actually higher than that for its predecessor the total proportion of the budgets of large research libraries that is spent for the processing of material as distinguished from the costs of its purchase or its direct servicing is now such as to give librarians pause for fear a day may come when nearly all the money available to large libraries will be spent in processing material and little will be left to service the collection or to buy new books
CISI	characteristics of the research literature used by chemists and physicists in the united states part ii this is the second of two papers dealing with the characteristics of the literature used by research chemists and physicists in the united states the method of the study was fully outlined in th first article and will therefore not be repeated here the previous paper was devoted to a discussion of the importance of the literature of various subject fields to research in chemistry and physics the remarks that follow are directed primarily to a discussion of the temporal span of the literature the principal forms of the literature the national origins of the literature used in the united states and some attention is devoted to the more important serial titles
CISI	the librarian from occupation to profession an industrial society has an open class stratification system it offers some an opportunity to rise but it offers no guarantee against downward social mobility compared to other types of societies this one demands a wider variety of higher level skills and thus generates much pressure against the forces that in all societies tend to keep the individual in his original caste or class much of the resulting mobility is based on a radical change which has taken place in the occupational structure of modern industrial societies one which neither marx nor orthodox economists anticipated an expansion of the demand for professional and technical skills of a high order thus not only are individuals competing with one another in their efforts to rise in the class system but occupations too are engaged in the same competition and may move up or down in power prestige or income
CISI	interrelations among special librarys the present paper will first deal with some of the objectives etiology and requirements of the library network as it overtakes and embraces co operation next in this context of network development a number of activities involving special libraries will be reviewed by way of illustration and example the greatest proportion of special library interrelationships are on the surface at least random and informal we shall therefore concentrate on such arrangements as have about them some measure of structure and intent finally we will deduce from these examples the performance and promise which special libraries may offer to a total library network or information system
CISI	the cranfield ii relevance assessments a critical evaluation the relevance assessments belonging to the cranfield ii document query collection are shown to be faulty in the sense that many relevant documents were not so identified by the cranfield judges the implications of these omissions for the evaluation of information retrieval experiments based on the cranfield collection are examined in detail it is shown that numerical measures of retrieval effectiveness may be greatly altered bu consideration of the missing relevant documents and that a ranking of retrieval methods according to order of performance may vary as well
CISI	an economic analysis of library benefits libraries find it increasingly necessary to use their limited resources in the most efficient manner this requires the use of decision rules which permit library resources to be directed to those activities which yield the highest returns an effort is made to utilize part of welfare economics to suggest which groups of library users will provide the greatest return to society an evaluation of the traditional library functions of education information and leisure suggests that libraries should direct their resources toward educational activities and not toward recreation when public monies are involved a case can be made for subsidizing the library activities of school age children other explicitly involved in education disadvantages minority groups and governmental officials and staff since public and school libraries produce and distribute essentially the same services it is an uneconomic use of the communities resources to maintain two separate institutions one of which imposes costs on the other as children are forced to use public library facilities due to school library inadequacies
CISI	the review article its characteristics and problems the characteristics and problems associated with the review literature in the sciences were examined three major classes of review articles were identified 1 the annual review which aims to provide a systematic record of the contributions made within the previous year 2 the critical review which selectively evaluates contributions to the solution of a common research problem and 3 data compilations which are concerned with facts and findings rather than the opinions of the authors of papers from which the data are taken the role and control of the review article in medicine was described over the past fifteen years the ratio of review to nonreview articles in medicine has been on the order of 1 38 possible solutions to a number of problems associated with the review literature are discussed such as the selection of articles for review further examination of some critical questions relating to the production and organization of reviews will have to be undertaken before the review as a means of bringing the most significant information to its users will be accepted as a reliable adjunct to the original publications
CISI	measures of library effectiveness mathematical models of library operations are presented allowing managers to estimate measures of effectiveness for a library these models describe the amount of use made of resources by a user in a visit the distribution of book circulation in a collection the dependence of circulation on time and the effect of multiple copies on user satisfaction predictions are made on the basis of the models of the consequence of breaking of central library into branch libraries the effect in terms of frustrated use of removing the least used books from a collection is discussed as are strategies for for duplication the emphasis is on facilitating getting results from models for this purpose graphic techniques supplement the mathematical formulas
CISI	library operations research a process of discovery and justification this article begins with a discussion of the broad role of operations research o r in a society undergoing change the nature of o r terms in a library environment is then considered the function of models in o r is analyzed the development of a model being contrasted with its formal presentation criteria for good models are suggested this article then focuses on storage models for libraries first considering the dewey classification system from this perspective and then summarizing more current research carried out under the direction of the author with a grant from the national science foundation
CISI	an operations research study of a variable loan and duplication policy at the university of lancaster the library research unit of the university of lancaster used an operations research o r approach to recommend changes in loan and duplication policies in the university library the variable loan and duplication policy which was developed is described and also the considerable impact of implementation other libraries are now adopting this kind of policy the work is presented as a case study in library o r the great importance of analyzing the structure of problems is stressed and the nature and usefulness of models is described for the most useful results suitable librarians should be included in the research team
CISI	library objectiveness and performance measures and their use in decision making for optimal allocations of limited funds it is necessary for libraries to develop measures of output various forms of user exposure to documents are discussed in an effort to develop such measures for public libraries it is suggested that the actual method of accounting be used to compare such measures with costs and an illustrative computation is presented it is shown how size of user population amount of exposure and costs for a given year can be estimated similar techniques are suggested for evaluation of library programs this approach is then compared with current concepts of library standards the paper concludes with suggestions for further research
CISI	catalog use in a large research library concern with the questions of when and how best to computerize the catalog of a large research library and how to improve an existing conventional catalog motivated a study of the utilization of the main catalog of the yale university library the study was carefully designed to provide a representative sample of catalog use traffic through the catalog area was observed over a period of more than a year a schedule of interviews with catalog users was based on observed traffic volume by hour of day day of week and time of year more than 1 000 interviews were completed using nonleading interviewing technique information was derived on the catalog users objective starting clues and university affiliation search success was determined follow up studies were performed on the catalog cards and the actual books identified in successful searches reasons for search failure were determined for know item searches availability and accuracy of different categories of search clues were ascertained published algorithms for searching computerized bibliographic files were evaluated attention is given to the feasibility of automatic construction of computerized catalogs some of the available results are presented and discussed
CISI	efficiency criteria for the operation of large libraries it is rather surprising that behavioral scientists have not discovered libraries much sooner in their search for institutional environments suited for the testing of theoretical hypotheses librarians and their assistants respect research and scholarship and are inclined to go far beyond the call of duty in helping the investigator even when they are skeptical rightfully in most instances of the usefulness of such research for the improvement of their own organizations data and related information are necessarily treated with greater precision and discipline in libraries than in factories and most bureaucratic offices therefore significant results can often be obtained with smaller samples and in shorter periods of observation people working in libraries do not feel they should curtail disclosures about basic processes elsewhere professional employees are obligated to preserve trade secrets from competitors or to suppress facts which might be considered scandalous by legislative committees at least as important to an investigator is the fact that one or more libraries almost always lie close at hand   there could hardly be any more convenient institution
CISI	the information needs of current scientific research the information demands or information needs of current scientific research are similar in many respects to the information needs in other forms of scholarship but this is not true in all cases and the focus of this paper is on the needs of the research scientists in discussing the information needs of the scientist i shall not limit myself to those for which library work is immediately relevant in fact a good part of this paper will call attention to the importance of those aspects of scientific communication that take place outside libraries and indeed outside literature there are of course very few aspects of scientific communication to which library work is not at least indirectly relevant
CISI	the evidence underlying the cranfield results an indexing or classification system should be judged by the retrieval results it produces namely the extent to which it brings forth relevant material and rejects the irrelevant thus well designed experiments should permit judging the relative merits of different classification schemes this notion although self evident had remarkably little impact on the field of library science prior to the 1950s during that decade the first controlled experiments on information retrieval were performed and these mark a turning point in the history of classification research for the first time experimental procedure and the rules of scientific evidence became of critical importance to indexing and classification it is my purpose here to review some aspects of the most notable of these experimental tests   the aslib cranfield research project
CISI	on improving communication among scientists libraries and information services of the twenty first century almost certainly will be the beneficiary or perhaps the victim of enormous technological change high speed search by computers microrecording techniques remote interrogation consoles and great communication networks will someday place the worlds knowledge at our fingertips it is inferred by many that through such a metamorphosis we shall cure the information ills of our age bring order out of chaos and somehow contain the information explosion   or at least reduce it to a small conflagration
CISI	the ecology of privacy the purpose of this article is to discuss the part played by the library environment in regulating interaction between people
CISI	paper deacidification a preliminary repot the purpose of this paper is to develop an approach to a practical treatment for the wet deacidification of paper in books stored in libraries
CISI	fields of information on library of congress catalog cards analysis of a random sample 1950 1964 the information systems office iso of the library of congress has as its mission the development and implementation of the main automation program for the library and the co ordination of all lc automation efforts one of the primary activities in this effort is a system development study concentrating on the central bibliographic operations that is acquisitions cataloging reference etc this study is now in its early stages and it is too soon to predict the actual system that will evolve as an adjunct to this study an analysis of the potential uses of and problems involved in the machine processing of cataloging data was begun one aspect of the analysis was the design of a preliminary machine  readable catalog record the results of this work are in a report issued by the iso as its planning memorandum number 3
CISI	paper impermanence as a consequence of ph and storage conditions this article aims to provide some basic information references to further information and a sense of proportion about the action of hydrogen ions and storage conditions on paper other important causes of paper deterioration such as oxidative degradation biological attack photocatalyzed degradation and mechanical wear and tear will not be considered at this time
CISI	graph model for library information networks the design and study of library information networks are enhanced by the use of the concepts which have been developed by graph theorists in this paper we expand upon this theme proposing a general network structure which we believe to be a good model for a wide variety of library and other information networks the basic concepts from graph theory are illustrated with the aid of a hypothetical public library access network plan
CISI	the divided catalog a summary of the literature in the earliest item 1905 in the bibliography here presented fletcher challenges the right of the dictionary catalog to be the overwhelmingly predominant type of catalog in libraries he questions its advocates claim that it best meets a librarys needs he advocates a divided catalog such as the one at amherst because for one thing the separate catalog can more readily be used in conjunction with bibliographies in the subject fields we find a similar argument in the latest item in the bibliography harris 1957 fletchers article seems to have been followed by more than thirty years of silence in the library journals on the subject of the divided catalog during that period there were probably some divisions of catalogs at some libraries but as thom q v indicates the greatest period of such activity started in 1937 our survey of the literature on the divided catalog corroborates this since 1938 in the year in which the steady stream of papers on the subject began
CISI	cost survey cost of ordering cataloging and preparations in southern california libraries it was our original intention to include the cost of book selection with the cost of ordering as part of the total acquisition process we also attempted to get indirect costs such as rent and utilities very few of the libraries were able to supply these figures so we based our survey on direct cost only we found from the preliminary survey that book selection statistics were extremely difficult to determine since all the professional staff in the libraries concerned participated in book selection with the chief librarian performing most of it as a result the cost of book selection was exceedingly high and threw the cost of ordering out of proportion
CISI	why allocate most academic librarians will no doubt agree with lyles statement that the book fund is one of the most important items in the library budget fewer academic librarians however are likely to agree with the view that in their handling of the book budget college and university librarians for the most part have not been living up to their professional responsibilities
CISI	cost accounting for the library increasingly librarians have felt the need for more accurate cost data the prime reason for this need has been in the development and presentation of the budget which is the instrument used to determine and obtain the funds for the librarys forthcoming fiscal period since libraries do not charge for the service they render their users they must derive the funds necessary for their operations and growth from supporting bodies such as federal state or local governments private institutions and industrial firms
CISI	a study of the usage and retention of technical periodicals limited physical space expansion an administrative consideration in every library becomes a stringent factor in the planning of special libraries while public and college libraries may have several decades of growth possibility when they take possession of a building or area it is indeed a fortunate industrial library whose stacks are not overcrowded after five years of establishment in new quarters industrial floorspace is too greatly in demand to devote more effort to the possible future growth of the library weeding or storage requirements therefore are far more immediate considerations to the special industrial library administrators than they are to administrators of other types of libraries the limits of expansion are usually apparent earliest in the serials collections of industrial libraries because so much current technical data is published first in scientific and technical periodicals these collections grow rapidly this summarization of a recent study made by one technical library in the area of space for use of technical journals has potential for other libraries
CISI	remarks on lc plans for implementation of new centralized acquisitions and cataloging program under title iic higher education act the general purpose of my part in this program discussion is to report to you on the new program of centralized acquisitions and cataloging to be undertaken by the library of congress under authorization granted under title iic of the higher education act of 1965 by this action the congress took two most important steps to aid libraries of higher education in the united states 1 it fully recognized for the first time the importance of granting federal aid and assistance toward solving the problem of cataloging in this country and 2 it gave the library of congress a clear mandate to provide new and unparalleled services for the benefit of academic and research libraries of this country
CISI	automated acquisitions procedures at the university of michigan library in june 1965 the acquisitions department of the university of michigan library began using a computer based system for ordering books and other library materials this is the beginning of an over all automated system for the acquisitions department and was designed with the assistance of robert o kindt systems analyst from the universitys office of management services preliminary work on the automated system was begun in late 1963 and in september 1964 mr kindt was assigned to the university library on a full time basis after the preliminary proposal was drafted cost and feasibility studies were made current i e 1964 volume and costs were compared with anticipated volume and costs in 1968 and 1975 for both manual and automated systems
CISI	facsimile transmission in libraries a state of the art survey facsimile transmission is the rapid transmission of printed pages from one point to another using electronic devices all facsimile transmission methods require converting the original picture into an electrical impulse which is then transmitted over telephone lines private lines microwave or a combination of these communication links the receiving unit reconverts the electrical impulse into an exact duplicate of the original document on a screen or in the form of a hard copy
CISI	statistics of collection overlap at the libraries of the six new england state universities as part of a design study to specify a regional processing center for the new england state university libraries it was required to know the percentage of collection overlap with respect to each of the 30 ordered pairs of 6 libraries participating states were maine new hampshire vermont massachusetts rhode island and connecticut this overlap data was needed to predict the degree of joint use of cataloging information and to estimate the efficiency of collective reclassification the results revealed a high degree of commonality in the 6 collections showing for example that a random title from one library had a 40 chance of being present in another randomly selected library when current imprint samples were tested the figure rose to 47 rhode islands holdings were shown to be the collection of greatest duplication elsewhere
CISI	logical flow charts and other new techniques for the administration of libraries and information centers the widespread introduction of electronic digital computer systems for information processing has produced significant advances in management theory and practice in recent years for example two management devices pert and cpm undeveloped and impractical before computers have been basic to the success of our outer space program it is perhaps overlate in library development but appropriate in this memorial to miss esther j piercy to explore the application of new management knowledge and practice to the administration of libraries and information centers and to sketch some directions in which research could be undertaken to benefit the management of information
CISI	criteria for weeding of collections growing library collections have focused attention upon the need for selective storage and weeding of the materials certain objective measures for determining which items in a collection may be retired to storage are presented and an example of the use of such measures at columbia university is described it is concluded that the criteria for weeding and storage must be selected on the basis of the goals of the institution in question and of the various patterns of use in different disciplines
CISI	cost analysis studies in libraries is there a basis for comparison when the chairman of the technical services cost committee asked the three of us to summarize the findings of the colorado study on centralized processing i agreed later i began to have second thoughts   i suppose because we were almost buried under an avalanche of data and it soon became apparent that we could not really summarize the findings of the study in one evening the investigation took off in tangents that had not been originally anticipated as you have already been informed the final report deals with such diverse topics as a faculty user attitude survey mathematical model simulations of processing center operations approval plan utilization and an inter institutional bookkeeping system all in addition to the cost studies of acquisitions and cataloging in nine libraries
CISI	the bibliographer in the academic library academic libraries in their quest to secure and make available library materials necessary to support instructional and research programs are finding it necessary to rely upon librarians functioning as book selectors the term bibliographer frequently applied to these selectors is gradually taken on new meaning in library service the role of the bibliographer is changing to include besides book selection new duties and responsibilities such as advanced reference research work instruction and liaison duties between teaching departments and the library in addition academic library organization is gradually being affected by the increasing use of bibliographers
CISI	medlars a summary review and evaluation of three reports the medlars medical literature analysis and retrieval system system at the national library of medicine nlm has over the past few years been one of the most significant and one of the most publicized automated bibliographic information retrieval systems over two hundred articles on it have appeared in american newspapers and popular magazines in specialized medical journals throughout the world and in a variety of library journals the publicity that has attended this project has in a way been unfortunate for it has presented an exaggerated picture of the system and its accomplishments which has only made the sceptics more skeptical and it has obscured in part the examination of medlars real accomplishments there has to date been very little careful outside analysis and evaluation of medlars over 50 percent of all the articles listed in the bibliography in austins report and virtually all the substantive ones represent the work of persons closely connected with nlm or the development of the medlars system their judgement on the effectiveness of the system and its overall value cannot help but be colored by this connection
CISI	cip in mid 1970 the history of the near success of the 1958 59 experiment with cataloging in source and the subsequent refusal of the library community to accept its failure are punctuated by data from a recent survey of 591 libraries in is categories regarding attitudes toward prepublication cataloging
CISI	report on library of congress plans for cataloging in publication when we were asked in october 1969 for an expression of attitude about a renewal of cataloging in source our response was positive we were interested and we were determined to make it succeed profiting from the experience gained in the 1958 59 experiment we specified that 1 a survey of libraries be conducted 2 a survey of publishers be conducted 3 an expert investigator be secured 4 there must be adequate funding 5 there be adequate space and 6 that those factors be eliminated which represented the most crucial problem areas in the 1958 59 experiment
CISI	an analysis of the universal decimal classification as a term system for nuclear science and technology explores the possibilities of merging the terminology of the universal decimal classification system with that of a term system   engineers point councils thesaurus   for nuclear science and technology concludes from the evidence presented that udc can be effectively used as a term system proposes that the two systems coordinate the terms and merge a major thesaurus ejc with an effective classification scheme of international scope udc to provide a needed tool in the area of classification and documentation
CISI	automation activities in the processing department of the library of congress this article reports on activities relating to the automation of technical processing at the library of congress the master guidelines for automation of the lc core bibliographic system are discussed and the following individual projects are described machine readable cataloging marc and related activities recon pilot project format recognition multiple use marc system order division project automated process information file subject headings project filing program book catalogs and the crad division project
CISI	filing arrangement in the library of congress catalogs new filing rules have been developed for the catalogs of the library of congress to ease the tasks of filers and users and to pave the way for computer assisted filing this article discusses preliminary considerations about the functions of large bibliographic files the complexities of cataloging the interaction between users and catalogs and ways to simplify arrangements the assumptions and principles that underlie the proposed rules are stated and their organization and anticipated use are described an abridged version of the rules is illustrated by an extended example
CISI	cataloging nonbook materials mountain or molehill the development of cataloging codes for nonbook materials in surveyed with particular attention devoted to the absence of stated objectives the problem of the integrated catalog terminology and examples and some of the complications caused by the blanket use of title main entry
CISI	an integrated user oriented system for the documentation and control of machine readable data files the purpose of this paper is to offer a solution to the problems of documentation and bibliographic control of machine readable data files it is a solution which attempts to meet both the needs of the data user and the data librarian it is design to make readily feasible the conversion completely or in part to a computer based operation and to tie in directly to an information retrieval system in the future the four elements of this documentation and control system are standard catalogue entries data abstract and data description forms content documentation codebooks and records of physical and logical characteristics of the data set
CISI	measuring reader failure at the catalogue in an effort to develop a simple method for librarians to employ to measure and evaluate author catalogue use the library management research unit tested a survey design in four varying libraries the reader was asked to note details of items not found in the catalogue the source of the reference and his status the items were then checked by library staff to discover the cause of failure library staff interviewed samples of catalogue users to determine the overall rate of failure the cooperation with catalogue query slips rate and the action readers proposed to take in order to obtain the item s not found in the catalogue
CISI	early warning generic medium designations in multimedia catalogues the much favored early warning generic medium designation is discriminatory functionally inefficient and out of line with the national and international acceptance of aacr a specific designation placed with the collation is preferable on all these grounds and there are better ways of giving an early warning
CISI	international developments in cataloging the ifla committee on cataloging has been at work since 1954 to establish international standards for cataloging and bibliographic records it was responsible for the international conference on cataloging principles paris 1961 and and the international meeting of cataloging experts copenhagen 1969 in recent years there have been increasing demands from national cataloging bodies and bibliographic agencies for uniformity in codes and practices and in consequence there has been more willingness to make national concessions in order to reach international standards the ifla cataloging secretariat was established in 1971 to assist this trend by co ordinating work promoting new projects and acting as a liaison center
CISI	the ohio college library center the ohio college library center is a regional library network its on line shared cataloging system has been operational since 18 october 1971 and utilizes cathode ray tube terminals located in the centers fifty three member libraries these terminals are connected to the sigma 5 computer in columbus by a multiple line multiple party synchronous transmission telephone network between january and june 1972 the system operated at an annual rate of 500 000 works cataloged and over 3 400 000 catalog cards produced these cards are individualized to fit the requirements of each member and are produced in packs designated for particular catalogs
CISI	the other half of cataloging the authors investigate the impact of a bibliographic retrieval card production system such as the ohio college library center oclc with special attention to its role in cataloging activities required at the local level to make the lc card a functioning component of the catalog are described the characteristics of the ensuring workload are examined along with methods of accomplishing it these activities are seen as a factor in the persistence of backlogs the design of oclc because of the immobility of the terminal and the absence of the catalog from the data base by passes this workload leaving the local library to accomplish it by the method of its choice as before or to leave it undone
CISI	the impact of international standardization on the rules of entry for serials the major provisions of the international serials data systems and the international standard bibliographic description for serials are presented and related to present rules of entry for serials as detailed in the anglo american cataloging rules
CISI	serial cataloging problems rules of entry and definition of title alternatives to the present rule for entry of serials in the anglo american cataloging rules aacr are identified and arguments relating to the concept of authorship for serials are summarized the varying concepts of title in aacr the international serials data system and isbd s international standard bibliographic description for serials are compared and the next steps relating to code revision and attempts at international agreement are described
CISI	the current state of standardization in the cataloging of serials current standards for the cataloging of serials including the anglo american cataloging rules isbd s international standard bibliographic description for serials and the guidelines of the international serials data system are discussed the varying needs of bibliographic catalogs and serials lists the latter serving primarily the functions of finding lists are described a distinction between complete and not complete works regardless of medium is suggested as an important consideration in the revision of the anglo american cataloging rules
CISI	aacr 6 time for a review two changes are proposed in the north american text of rule 6 of the anglo american cataloging rules aacr the adoption of the british text of 6b and the deletion of 6c both of these changes are intended to simplify the entry of serials with the deletion of 6c serials would be entered only under title or corporate author the adoption of the british text od 6b would in turn greatly simplify the remaining choice between title or corporate author
CISI	aacr isbd s and issn a comment it has been proposed recently that rule 6 of the anglo american cataloging rules aacr relating to entry of serials be replaced by the conventions for description of serials outlined in isbd s international standard bibliographic description for serials which in itself incorporates or accommodates another convention that of the keytitle an essential aspect of the international standard serial number issn viewed in the current library context this recommendation is irresponsible and indefensible on both a theoretical and practical level
CISI	international standards for the interchange of bibliographic records in machine readable form the paper describes the work in progress toward an international machine readable cataloging system and discusses the problems remaining
CISI	library response to urban change a study of the chicago public library this is the third in a series of studies of the chicago public library spread over fifty years the first a library plan for the whole city adopted in 1916 proposed expansion particularly in branch units the second a metropolitan library in action completed in 1939 proposed quality the achieving of recognized standards the underlying theme of the present report is adaptability the restructuring of the library in a period of change the first report practical and pragmatic achieved results the second for all its internal excellence had limited effect it is hoped that the present effort partakes both of the relevance of the one and of the integrity of the other
CISI	library service to the disadvantaged this volume is intended mainly as a source book for project and program ideas for libraries now engaged in working with the disadvantaged or planning to do so it is also hoped that it will give an overview of the progress to date in work with the disadvantaged by bringing together much of the thinking and many of the ideas that have appeared in literature or in conferences in the last few years
CISI	library systems analysis guidelines this book aims primarily to provide guidelines for library administrators and library systems analysts in analyzing and evaluating existing operating systems and in designing new or improved ones in addition we have found the material to be very useful in staff training programs conducted to ensure knowledgeable staff participation and cooperation in a systems study this guide is also adaptable for introducing library school students to the concepts of systems study in the library
CISI	the measurement and evaluation of reference service the measurement and evaluation of reference service has been more often discussed than attempted in fact the literature of this subject has itself spawned a fair sized literature of review admittedly the task is formidable as compared with other library activities such as circulation acquisitions and cataloging reference service is ill defined with little agreement on its component parts is inter library lending an integral part of reference work because many reference librarians are responsible for it formal instruction in the use of books and libraries the supervision of reference reading rooms the preparation of indexes and having decided what the genus reference librarian does how can one readily determine the effectiveness of his work or its impact reference librarians may have acted rather blindly in approaching their elephant of a problem but it is undeniably a big one
CISI	service to industry and research parks by college and university libraries the phrase research parks in the title of this article recalls eugene b jacksons 1961 prediction in 1980 there will be universally managed and industry sponsored special libraries in the vicinity of the principal universities their advanced use of new methods of bibliographic control information retrieval and data exchange will make their operations indistinguishable from those of special libraries of outstanding profit making organizations in the same subject fields significant assessments will be made on the participating organization in research parts not only for the financing of day to day operations of facilities especially set up for their benefit but also for the total enrichment of the university library resources
CISI	the science citation index a new concept in indexing the purpose of this paper is to discuss citation indexing and its present application as exemplified by the science citation index published by the institute for scientific information as a new unique and necessary tool for scientific work it is necessary therefore to describe briefly and in general terms the nature of conventional subject indexing systems in order that a basis for contrast between these and citation indexing can be obtained for those who wish to read extensively on the subject of indexing references are provided at the end of the paper under the section additional references
CISI	information network prospects in the united states unmistakable signs are pointing the way toward the creation sometime soon of a national information network in the united states the concept of a national network implies the interconnection of existing information systems and libraries through communications certainly one of the great strengths of this nation is the great array of intellectual scholarly and research resources to be found in its libraries and information centers without integration and close cooperation however these resources will remain a series of separate insulated institutions but if maximum communication can be established among them this array can be converted into a national resource of immense value to citizens throughout the country
CISI	standardization requirements of a national program for information transfer the authors of this article represent two specializations in the spectrum of information transfer activities that of the computer and communication system engineer and that of the librarian these points of view are combined in examining the requirements for standardization in the national efforts to use automation in publication library abstracting and indexing and information retrieval activities standardization is necessary to both the representation of information and to the procedures being developed for handling it
CISI	bibliographic and technical problems in implementing a national library network the problems facing the planners of automated library networks are rooted in the complexities of organizing and managing a vast flow of bibliographic information and its interface with users telecommunication equipment transmitting data in the form of electric signals electronic memories holding large stores of information and computers manipulating the data and graphic displays for human interaction are technological means for performing network functions more effectively than has been possible in the past
CISI	the microform revolution librarians have tried replacing some of their books and journal files with microfilm copies or other microforms in order to save valuable space in the bookstacks instead of or in addition to extension of the stack area decentralization compact shelving separate storage warehouse or any of the other solutions to the storage problem discussed in earlier chapters as a final paper this solution for the storage of library materials will be discussed although the distinct forms will not often be designated microform is used here to mean the four forms most common in the united states 35 mm roll microfilm microfiche now standardized in the united states and great britain at 4 by 6 inches and the two micro opaque forms   3 by 5 inch microcard and 6 by 9 inch microprint
CISI	participative management as related to personnel development theory and practice regarding patterns of decision  making in libraries have been relatively neglected aspects of library administration yet the decisions by which a library attempts to control its operations are of major importance to its welfare and effectiveness recent theories in management and social psychology have addressed themselves to the implications of participative management and group decision making and their findings appear to have important applications to libraries not the least of which is personnel development
CISI	numerical methods of bibliographic analysis it is only in the last eight or ten years that the numerical aspects of bibliography have attracted attention although some of the numerical regularities that occur in bibliography have been known for thirty or forty years results are therefore still meager and applications are still few moreover most of the work so far reported has been limited to numerical analysis of the literature of the natural sciences this is in part because the secondary sources in the natural sciences are the best organized and so provide the most accessible data in part because the literature of the natural sciences are the least restricted by linguistic barriers and in part because the proposed world  wide systems such as those advocated in the unisist report offer an immediate field of application in the design of economic and efficient systems based on the results of numerical bibliographic analysis however the field of possible application is gradually widening serious efforts are now being made to organize the more diffused literatures of the social sciences for example
CISI	evaluation of adult reference service the evaluation of reference service has received considerable attention in the literature over a comparatively long period but as samuel rothstein pointed out in his 1964 library trends article on the measurement and evaluation of reference service much of the literature has focused on discussing the lack of evaluation or the shortcomings of the evaluation that has taken place in the ten years since rothstein wrote his article there does seem to be more effort at evaluation of reference service undoubtedly many of the trends in recent evaluation are due to the influence of rothsteins article
CISI	the librarys public a report of the public library inquiry the following report on use of the public library is the product of two separate studies made for the public library inquiry one was the national sample survey of library use made for the inquiry by the survey research center of the university of michigan personal interviews of a half hour or more in length were held with 1 151 people selected at random in different counties scattered over the united states the sample was designed so as to represent all adult persons living in private households by this tested method the survey gathered information concerning the amount and the kind of use people make of the public library and what changes or extension of library service people in general would prefer the survey also gathered information on the use of books obtained from sources other than the public library as well as the extent of regular use of newspapers radio magazines and movies
CISI	determining the optimal number of volumes for a librarys core collection the concept of the core collection in a large library is not new the thought behind such a concept is to provide a separation of the more frequently used volumes from those that are infrequently used there have been however difficulties in determining what volumes are to be included within the core collection it is usually necessary to establish a committee or group of professional people who determine usually by enumeration those volumes that should be included in the core collection often the results of such a determination merely reflect the opinions of the individuals and although valid in many cases as desirable reading the core collection that results may not be a reflection of user requirements
CISI	ifla   communications   fiab the traditional pattern of organization of national and university libraries apart from those in germany or affected by german practice was imposed by the weight given to the processing divisions the order department which in university libraries did not include experts in book selection was not considered to be of comparable importance with the major department    the cataloguing room which also housed the classifiers other divisions would be concerned with particular types of material    maps state papers or official documents manuscripts oriental books    and would be largely autonomous with regard to acquisition and cataloguing the reading room staff were mainly employed in assisting readers to use the catalogue and in answering queries of a very specialized nature on the librarys collections especially on manuscripts or early printed books they rarely dealt with the general bibliographical or reference type of enquiry which is put to present day reference librarians in these circumstances members of staff tended to become expert in the work of their own department and not be invited to take any part in the activities of another divisions between the various kinds of work were therefore hard and fast and the structure of the librarys organization could become similarly rigid it must be appreciated that this is a generalization and that many libraries were more fluid in their approach nonetheless this conservative view of the librarys function tended to freeze the administration into this form an expert in a particular subject field often undertook research in the subject outside the library and might occasionally be asked to deal with a reader enquiring about an aspect of his field but usually he would not make much use of his expertise in connection with his library duties unless of course he was appointed as a paleographer orientalist or linguist the appointment of subject specialists may therefore necessitate a complete re modelling of the staff organization if their influence is to extend beyond the bounds of the old departments
CISI	the subject specialist in national and university libraries with special reference to book selection of the worlds numerous kinds of libraries the national and the university may properly be characterized as having responsibilities for both general and universal or nearly universal collecting in the realm of scholarship that is these two and only these two commonly collect over a very broad spectrum and in depth material which makes possible the creation of new knowledge herein lies the paramount importance of these libraries to society if it be granted as it is here assumed that almost no field of human endeavor can advance without resort to the recorded past it is this twin aspect of the activity of these scholarly libraries   collecting simultaneously in breadth and in depth   which produces most of their major problems the concern of this paper is with two of these problems which seem by far the most important and difficult the selection of materials and the utilization of subject specialists
CISI	information science in librarianship these information systems create a real challenge for librarianship since on the surface it would seem that librarians can have a central role in their development their operation and their management but to do so librarians must recognize the contribution they can make and be willing to accept the challenges
CISI	weeding the collection a review of research on identifying obsolete stock reverberations of the publishing explosion of recent years are reaching us now production of monographs and journals research reports and government documents has been increasing exponentially to the point that british university librarians are beginning to feel the sense of constriction of space which their american counterparts have been struggling with for a number of years judging by the amount of print devoted to the subject in american library journals the force of this sense of constriction has been somewhat mitigated in all but the copyright libraries by the general lack of funds available for book purchasing and by the increasing price of books however when space in the library does become filled obviously something must be done to create more space because the flow of material is certainly not going to cease
CISI	precis in a multilingual context the present paper is offered as the first of a series of articles in which precis will be reviewed as a potential multi lingual system having in mind the obvious need notably in a european context for standard and language  independent methods of subject analysis and document description this first paper outlines the origins of precis and considers its use in english  language indexing a second paper will deal in general terms with the syntactical model which is used for producing precis input strings and index entries later papers will then review the application of this model to indexing in firstly the germanic languages e g german and danish and secondly the romance languages illustrated by french
CISI	limits growth in april 1968 a group of thirty individuals from ten countries   scientists educators economists humanists industrialists and national and international civil servants   gathered in the accademia dei lincei in rome they met at the instigation of dr aurelio peccei an italian industrial manager economist and man of vision to discuss a subject of staggering scope   the present and future predicament of man a series of early meetings of the club of rome culminated in the decision to initiate a remarkably ambitious undertaking   the project on the predicament of mankind the intent of the project is to examine the complex of problems troubling men of all nations poverty in the midst of plenty degradation of the environment loss of faith in institutions uncontrolled urban spread insecurity of employment alienation of youth rejection of traditional values and inflation and other monetary and economic disruptions
CISI	line   formula chemical notation this manual is the culmination of a long search for a chemical notation that should consist of symbols limited to those on the standard typewriter keyboard the necessity for such a notation has been made almost inescapable by recent tremendous advances in technology and the vast growth of chemical literature
CISI	linguistics and information science this study was commissioned by the committee on linguistics in documentation of the federation internationale de documentation fid it is concerned with the linguistic aspects of information science and in particular with the linguistic components of document analysis description and retrieval we have attempted to relate linguistics and information science by considering the theories and techniques linguistics has to offer and how far these have been or could be exploited by information scientists we have examined these questions within the context of automated language processing and automated documentation the use of computers for linguistic operations presents special challenges as well as interesting possibilities and we have chosen to approach the field from this particular point of view
CISI	a list of books for college libraries to permit a qualitative estimate of a college librarys resources the advisory group on college libraries of the carnegie corporation authorized the compilation of a list of not less that 8 000 nor more than 15 000 titles which might be regarded as a statement of the minimum or basic book collection of a four year liberal arts college the procedure on which the advisory group decided included 1 the selection of a librarian under whose direction the compilation should be made 2 the checking and improvement of the original lists drawn up by this compiler by such a homogeneous group as the faculty of a single college and 3 the submission of these revised recommendations to an able group of widely scattered college teachers for further revision
CISI	a little commonwealth family life in plymouth colony the kind of study presented in this monograph has not as yet won a wide following among working historians on the whole their interest has remained with the larger units of social action the region the class the party the ethnic or religious group it has been left to the so called behavioral sciences   anthropology sociology psychology   to demonstrate the fundamental importance of the smallest and most intimate of all group environments the family
CISI	little science big science pegram lecturers are supposed to talk about science and its place in society the ordinary way of doing this would be either to talk popular science or to adopt one of the various styles in humanistic discussion of the reactions between men and science previous lecturers in this series have given accounts of the content of space science and made excursions into the philosophy and the history of science although professionally my concern is with the history of science i have a certain prehistoric past as a physicist and this has led me to treat these lectures in what is perhaps an extraordinary way my goal is not discussion of the content of science or even a humanistic analysis of its relations rather i want to clarify these more usual approaches by treating separately all the scientific analyses that may be made of science why should we not turn the tools of science on science itself why not measure and generalize make hypotheses and derive conclusions
CISI	the logic of comparative social inquiry the ideas presented in this book developed during the course of our participation in a comparative research project the international studies of values in politics which was a study of the relationship between characteristics of local political leadership and the behavior of local governments in india poland the united states and yugoslavia among the first problems we confronted were those of measurement in the fall of 1965 the first pretest of value scale items was under way the goal of the pretest was to develop valid and reliable scales of values in four national samples the second problem we had to face arose from the nees to obtain comparable measures of community activeness in four countries
CISI	londoner and his library this report deals with a complementary theme the public for which the public library service is provided it does this in two ways   by giving information about the nature of that public as it is at present made up and by reporting what people say about public libraries not only those who are members but also those who used to belong and those who never have its closest relatives in british writing on this subject are therefore mass observations now dated reading in tottenham 1947 and the society of young publishers survey books in london 1959 it is more comprehensive in scope and more detailed in its analysis that the tottenham survey while it goes in some depth into issues that necessarily played only a small part in books in london
CISI	the making of a library a book like this is a cumulation of experience thought error and hopefully learning of many years it did not start like a water faucet at precisely that moment in 1967 when the office of education so kindly awarded a grant to hampshire college for the development of the concept of the extended and experimenting library although the grant was certainly the means for and a spur to it formalization
CISI	mans aggression the purpose of this book is to inquire into the validity of the views on human nature expressed in the widely read and influential books of robert ardrey and konrad lorenz ardreys books are african genesis atheneum 1961 and the territorial imperative atheneum 1966 lorenzs book is on aggression harcourt brace world 1966 in these books the authors argue that man is by instinct an aggressive creature and it is this innate propensity to violence that accounts for individual and group aggression in man
CISI	man machine communication this book is an introduction to the elements methods and problems of interactive systems and is tutorial in tone it is intended for both users and designers of conversational systems those who actually operate them as well as those who design the overall systems in which they are used i would expect primarily to draw my readers from among the designers of information systems and such prospective users as teachers writers librarians lawyers design engineers and professional managers the book is a survey and is not intended as an exhaustive text the reader wishing to pursue any topic in detail will have to seek further but i have provided references to help him do so
CISI	the management of innovation all the research reported in this book arose out of an attempt some years ago to study an industrial concern as a community of people at work that is in much the same terms one would use in a study of conduct and relationships in a village an urban neighborhood or a small primitive community this aim was never realized because it soon became evident that the social structure of the factory interlocked with and often mirrored that of the small isolated town in which it was situated the wider study which then appeared necessary was not practicable and the enquiry petered out rather inconclusively assuming its present significance only in the context of later studies
CISI	towards a behavioral theory of communication this paper presents a conceptualization of information as related to the decision problems of the recipient the orientation is toward a formal definition of behavioral elements in an individuals purposeful state specifically these elements are his objectives his valuation of each objective his possible courses of action the efficiency of each course of action in achieving each objective and his probability of choice for each course of action the amount of information in a purposeful state is explicitly defined in terms of the probabilities of choice of the available courses of action the amount of information in a message is defined as the difference between the amount of information in the purposeful state following the message and the amount of information in the purposeful state preceding the message the amount of instruction in a purposeful state is defined in terms of the efficiencies of the available courses of action and the amount of motivation is defined in terms of the values of the objectives the amounts of instruction and motivation in a message are defined just as information is by comparing the amounts in a purposeful state before and after receipt of the message the value of a purposeful state to an individual is defined as a function of the amount of information the amount of instruction and the amount of motivation in the state this concept can be generalized to express the value of the state to some other individual
CISI	management misinformation systems five assumptions commonly made by designers of management information systems are identified it is argued that these are not justified in many if not most cases and hence lead to major deficiencies in the resulting systems these assumptions are 1 the critical deficiency under which most managers operate is the lack of relevant information 2 the manager needs the information he wants 3 if a manager has the information he needs his decision making will improve 4 better communication between managers improves organizational performance and 5 a manager does not have to understand how his information system works only how to use it to overcome these assumptions and the deficiencies which result from them a management information system should be imbedded in a management control system a procedure for designing such a system is proposed and an example is given of the type of control system which it produces
CISI	computational analysis of scoring models for r and d project selection several authors have proposed using scoring models for prescriptive analysis of the r and d project selection decision problem this research indicates that these models do not meet with important practical requirements for example many authors recommend a multiplicative index over an additive index in order to generate a wide range of project scores the additive index is shown to have important advantages over the multiplicative index the most serious shortcoming in the models however is the relatively arbitrary fashion in which the models have been constructed and the failure of the model builders to recognize the impact of certain structural considerations on resulting project scores comparative analyses relating project rankings produced by scoring models to rankings produced by a profitability index and by a linear programming model demonstrate that the performance of the scoring model is highly sensitive to decisions made during the development of the model considerations such as 1 the underlying distributions of project data 2 time preferences 3 the number of ranking intervals or categories and 4 the width of the intervals all have important implications for final project scores and associated rankings
CISI	a scoring methodology for assessing the suitability of management science models in this study five major criteria realism flexibility capability case of use and cost for evaluating the suitability of management science models for r d project selection are established through personal interviews with r d administrators and management scientists a suitability rating system based on these criteria is used by the author to rate twenty six management science models for their suitability of use in r d project selection decision making profitability index and scoring types of models were found to have generally higher ease of use and lower cost performances than the other types the linear and nonlinear models had generally higher flexibility while the linear nonlinear and zero one models had generally higher realism than the other model types
CISI	the managerial grid the managerial grid method of designating various styles of leadership avoids these semantic traps even more it shows how a leader can simultaneously maximize both the methods which are production oriented and those which are people oriented thus instead of putting a manager in a dilemma of choosing one or the other alternative it illustrates that there are ways he can gain the benefits of both it puts various methods of managing problems into a framework where the leader can identify study and change his own behavior thus he is in a position to understand it better to evaluate the results it produces and to encourage its use by others
CISI	the marc ii format a communications format for bibliographic data the marc machine readable cataloging pilot project was an experiment to test the feasibility of distributing library of congress cataloging in machine readable form to a variety of users this project grew out of the conviction of many librarians that automation was becoming necessary if libraries were to keep up with the rising tide of new materials and the mounting demand for rapid information although there were other library procedures which stood to profit from mechanization it was felt that devising a method of recording bibliographical information in machine readable form was basic to the solution of other problems
CISI	the marc pilot project the final report the marc project has progressed from a pilot to test the feasibility of a distribution service of centrally produced machine readable cataloging data to a full scale operational system in the design stages in two short years the library community both here and abroad has accepted marc and recognizes its potential for the future the single most significant result of marc has been the impetus to set standards there is no doubt that eventually standards would have been designed for machine readable bibliographic records character sets and codes for place and language marc accelerated standardization and still more important the standards are being set and agreed to be a large segment of the library community the cooperation among the producers and users of bibliographic description has been a rewarding experience
CISI	mathematical taxonomy in this book we give a mathematical account of some of the methods of data simplification which are involved in or suggested by the practice of biological taxonomy the computable methods derived are offered as potentially useful tools for taxonomists rather than as substitutes for their activities superficially similar problems of data simplification arise in pattern recognition and in the various sciences which make substantial use of classificatory systems biological taxonomy ecology psychology linguistics archaeology sociology etc but more detailed examination shows that the kinds of classification used and the kinds of data on which they are based differ widely from science to science whilst we recognize that some of the methods described here particularly in part ii of the book are more widely applicable we have deliberately limited discussion to biological taxonomy the emphasis throughout is on the clarification of the mathematical properties of methods of automatic classification and of the conditions under which their application is valid so that anyone who wishes to apply the methods in other fields shall be aware of their limitations and of the lines along which they may profitably be developed and modified
CISI	the mathematical theory of communication the word communication will be used here in a very broad sense to include all of the procedures by which one mind may affect another this of course involves not only written and oral speech but also music the pictorial arts the theatre the ballet and in fact all human behavior in some connections it may be desirable to use a still broader definition of communication namely one which would include the procedures by means of which one mechanism say automatic equipment to track an airplane and to compute its probably future positions affects another mechanism say a guided missile chasing this airplane the language of this memorandum will often appear to refer to the special but still very broad and important field of the communication of speech but practically everything said applies equally as well to music of any sort and to still or moving pictures as in television
CISI	meaning and the structure of language the work to which this chapter forms a preface arises out of a deep and prolonged dissatisfaction which the author has felt with both past and present theories of the structure of language this dissatisfaction may be understood more readily and the suggestions which make up the body of this work may appear in clearer perspective if i begin with a few remarks of an autobiographical nature the intrinsic importance of these remarks is minimal but they may provide a useful background for what follows
CISI	measurement of meaning the scientific study of language has been developing with particular rapidity during the past decade or so one thinks immediately of the basic work of zipf and skinner of the developments in information theory in concept formation in second language learning in work association research and generally of the increasing integration of the psychological and linguistic approaches as reflected in the activities of the social science research council committee on linguistics and psychology almost every new issue of a social science journal brings additional evidence of this heightened activity a significant aspect of much of this development has been the devising and application of new quantitative measurement techniques during the past six or seven years a group of us at the university of illinois has been concentrating on the development of an objective measure of meaning and this book is largely a progress report of that research
CISI	measurement of satisfaction in work and retirement the focus of the book can be summed up in its subtitle a strategy for the study of attitudes this strategy is developed by devoting considerable attention to the nature of the concept of satisfaction and particularly to the requirements for scientifically adequate measures of satisfaction in fact it is the emphasis on a comprehensive set of requirements for sound measurement rather than on just one or two elements of it which is the quality that sets this book apart from any previous report in the area of job satisfaction not the least of the values of this book is its basic utility for both academicians and practitioners for the former it should serve as a powerful spur and guide to further fundamental research on the nature and correlates of satisfaction for too many years we in this area have been plagued by inadequately conceived and poorly developed measuring devices this has led to a plethora of studies each using a different scale or measuring instrument as a consequence this has opened the door for almost anyone to claim the solution for making sense of the jigsaw pattern of findings relating to satisfaction at the very least the present volume should provide researchers with a thoroughly developed measuring instrument that will allow comparability of results across studies if so this may well bring some meaningful order to the present rather chaotically structured literature on job satisfaction
CISI	measuring the quality of library service a handbook there is probably no measurement task which public servants face which is more difficult than that of measuring the quality of service it is as difficult to measure the quality of hospital service or of schools or of social welfare programs as it is to determine the quality of library service it is equally as difficult to decide what actions to take in order to improve service legislators urban and regional planners consultants boards of trustees accrediting teams librarians and a host of other decision makers must act on the basis of some conclusions about the quality of service offered by library systems this handbook is intended for these groups and especially for practicing librarians the pervasiveness of the problem across all public service institutions however leads us to hope that the handbook will be of interest to other groups
CISI	medical innovation a diffusion study the research reported here constitutes a case study in the acceptance of an innovation the innovation is a medical one a drug which physicians use in everyday practice the setting is in the midwestern united states in the 1950s this study gives a glimpse of one small part of the great changes that have recently occurred within medicine and thus is of specific interest to the medical profession and its allied institutions but more generally the question of the spread of an innovation is of interest to all students of society particularly in an age of change and in our complex and massive society an understanding of the way in which an innovation can spread   for better or worse   constitutes important knowledge of man it is to aid in this understanding as well as to describe the case at hand that this report is written
CISI	medlars 1963 1967 the purpose of this document is to present a final description of the system as it has evolved through a period of four years of operation this will add the final chapter to the present medlars story at a time when the library is on the threshold of developing an entirely new system utilizing the latest techniques of documentation and information science coupled with modern third  generation computer equipment the reader interested in a complete chronicle of the librarys experience with medlars is advised to combine the reading of this report with a re reading of the original medlars story thus he will be able to develop a complete picture that answers the questions 1 what did the library set out to do 2 what was actually accomplished and 3 what changes were made in the original system design and why
CISI	melcher on acquisition this book originally set out to be a kind of reporting in depth of the american library association pre conference on acquisitions held in atlantic city in the summer of 1969   a report embracing not only the essential content of the formal speeches but also the floor discussions and after hours bull sessions meanwhile however a closely similar treatment of the problem of how to buy library materials long in process suddenly shaped up and was published by ala in november 1969 this was purchasing library materials in public and school libraries by evelyn hensel and peter d veilette a treatment of the acquisition process in college and university libraries was also taking shape at this time and became the january 1970 issue of library trends the acquisition problems of research libraries were likewise getting detailed examination in the two annual international seminars on approval and gathering plans in large and medium size academic libraries sponsored by western michigan university in the fall of 1968 and the fall of 1969
CISI	methods of information handling this book is meant to be an aid and reference work for those people who are interested in the design of information systems such information systems are typified by the traditional libraries but the same problems of information processing storage and retrieval are present in many government and industrial organizations in many places besides the library this book provides an illustration of the tools equipment and methodology that might be applied to those problems
CISI	relevance predictability in information retrieval systems an experiment is described which attempts to derive quantitative indicators regarding the potential relevance predictability of the intermediate stimuli used to represent documents in information retrieval systems in effect since the decision to peruse an entire document is often predicated upon the examination of one level of processing of the document e g the citation and or abstract it became interesting to analyze the properties of what constitutes relevance however prior to such an analysis an even more elementary step had to be made namely to determine what portions of a document should be examined an evaluation of the ability of intermediate response products irps functioning as cues to the information content of full documents to predict the relevance determination that would be subsequently made on these documents by motivated users of information retrieval systems was made under controlled experimental conditions the hypothesis that there might be other intermediate response products selected extracts from the document i e first paragraph last paragraph and the combination of first and last paragraph that would be representative of the full document as the traditional irps citation and abstract was tested systematically the results showed that 1 there is no significant difference among the several irp treatment groups on the number of cue evaluations of relevancy which match the subsequent user relevancy decision on the document 2 first and last paragraph combinations have consistently predicted relevancy to a higher degree that the other irps 3 abstracts were undistinguished as predictors and 4 the apparent high predictability rating for citations was not substantive some of these results are quite different than would be expected from previous work with unmotivated subjects
CISI	the use of biomedical periodical literature at the national lending library for science and technology the paper reports the results of a two week questionnaire survey of the use of biomedical periodical literature carried out at the uk national lending library in february 1969 the survey was designated to discover the subject date and language characteristics of the borrowed literature the most frequently requested journals and the most popular sources of references to biomedical publications the loans were spread over 1 084 titles although 9 per cent of the issues involved only 2 per cent of the titles the literature in most demand was less than one year old and in the case of medicine 50 per cent of the requests were for literature lss than 3 1 2 years old the half life for the biological literature was somewhat longer at 5 3 4 years the majority of issues 87 8 per cent involved english language periodicals overall the principal sources of references to the requested literature were citation lists in other periodical articles regarding the more recent literature however abstracting and indexing journals were the primary sources of information for medical references index medicus was the most used indexing publication and for biological references current contents
CISI	metropolitan public library public libraries in the 1960s which are active and alert and interested in meeting the interests of their various publics face problems far different from those of even a decade ago the maryland metropolitan area is an example of the many changes taking place in metropolitan areas which require corresponding change in the type and form and arrangements for library service and even demand looking into the very nature of library service itself
CISI	the microtext reading room part ii part i dealt with the selection of a microtext manager and with procedural consideration in the acquisition process part ii continues the discussion about acquisitions including considerations of format variation and reliability of publisher supplied project information the librarys search for an adequate system of bibliographic control is examined cataloging methods classification schemes and hardcopy guides and indexes are discussed as components of bibliographic control
CISI	user resistance to microforms in the research library microforms enjoy only limited acceptance in research libraries largely because of user resistance a growing number of published studies indicate that improper production inadequate bibliographic access lack of standardization defects in equipment design maintenance problems poor environments for microform usage and certain inherent characteristics of the microforms themselves all combine to make their use inconvenient solutions to most of these problems have existed for some time but the microform industry has been slow to correct them some positive developments have occurred in the last two years but the major problems remain
CISI	microform information sources publications and hardware this article lists and describes articles books and services that provide information about publications available in microform and about microform hardware
CISI	microforms in libraries why do libraries use microforms according to a 1974 survey by a micropublisher saving space was the reason given by most respondents holmes on the other hand found to acquire materials not otherwise available as the major reason others include 1 instead of binding serials journals are retained unbound for two to three years after publication the period of heaviest use and are then discarded and replaced by microform versions 2 to preserve deteriorating materials 3 easing access to bulky materials such as newspapers 4 to provide working copies of materials too delicate for continued use such as rare books 5 to save money   in most cases the cost of an out of print set or serial backfile will be substantially less in microform than the cost of a full size reprint or the cost of the original on the used book market 6 ease of acquisition   i e acquiring materials which would otherwise be difficult to acquire 7 mutilations reduced
CISI	milestones in cataloging in the case of the present study dr lehnus was interested in applying a method   in a non standard way for that method   to a type of literature that had not been addressed so far he proposed to begin with a single monograph on the subject cataloging apply the method of citation analysis to the references of that work and determine whether a core literature on cataloging could be discovered in this way there are innumerable examples of core literatures in scientific fields obtained from journal articles or through the science citation index but research via the monograph in non  scientific subjects has been minimal
CISI	patterns of evaluation in science institutionalization structure and functions of the referee system the referee system in science involves the systematic use of judges to assess the acceptability of manuscripts submitted for publication the referee is thus an example of status judges who are charged with evaluating the quality of role performance in a social system they are found in every institutional sphere other kinds of status judges include teachers assessing the quality of work by students and as a recent institutional change students officially assessing the quality of performance by teachers critics in the arts supervisors in industry and coaches and managers in sports status judges are integral to any system of social control through their evaluation of role performance and their allocation of rewards for that performance they influence the motivation to maintain or to raise standards of performance
CISI	the development of a scientific specialty the phage group and the origins of molecular biology this paper analyses the formation of a new discipline molecular biology from the development of phage work it argues that such social variables as the competitive position and relative status of each of the specialities or disciplines from which a new one is formed are not sufficient to explain phage works development into the specialty of molecular biology even though persons in physics a field with high academic standing decided to enter biology which had a lower academic standing and even though some recruiting of students occurred these factors alone are not sufficient to account for the development of the specialty particularly given the competitiveness of modern conditions in the emergence of molecular biology from phage work the variables of status and competitive position adduced by professors ben david and collins to explain the emergence of experimental psychology from the hybridization of physiology and philosophy seem to be less important than other normal activities which occur in scientific development
CISI	modern manuscripts a practical manual for their management care and use the title of this book is intended to indicate that its scope is limited to manuscripts of the seventeenth century to the present examples and techniques are drawn from institutions in the united states with occasional references to practices in great britain and canada the book is directed toward the novice curator of manuscripts and again as the title indicates it is intended to serve as a practical guide not as an exposition of theory
CISI	modern organizations the plan of this book follows our definition of organizations as social units that pursue specific goals which they are structured to serve obviously under some social circumstances therefore the book has three foci organizational goals organizational structure and organizations and their social environment considerably more space is devoted to organizational structure than to the other topics for two reasons first more research has been conducted and more writings are available on organizational structure than on organizational goals chapter 2 and environment second the major schools of organizational analysis have fixed their interests on structural aspects of the organization and thus we may best evaluate these different approaches in the context of organizational structure
CISI	a modern outline of library classification this outline is based mainly on lectures given at the north western polytechnic to students studying for the library associations registration examination in classification and cataloguing it is hoped that it will help to meet the need increasingly felt in recent years by students and teachers of the subject for a reasonably simple textbook on library classification which takes account of the considerable developments which have occurred in the subject in the past 25 years as is well known a great deal of this has been due to dr ranganathan and also in more recent years to mr b c vickery as a result of these developments a coherent theory of library classification has been established in each of its three major departments   in subject analysis in notation and in the alphabetical indexing of systematic orders it is now possible to construct library classifications whose efficiency in the two basic functions of relating subjects helpfully and of locating them rapidly ad unerringly is considerably greater than the schemes we have so far used moreover they are easier to construct
CISI	modern systems research for the behavioral scientist a sourcebook although it is hoped that this sourcebook will be of interest to those of any discipline concerned with new developments in science of the last quarter century it is addressed principally to the student of human behavior as that study is approached from the social side this is so partly because that is the editors main competence and interest but primarily because the study of human behavior is the general area of science that has least responded to the exciting challenge of the modern systems outlook yet it is precisely this general area that stands to gain the most from insights into the workings of the more complex types of systems
CISI	monteith college library experiment our report on the analysis of social structure in the monteith library project begins with discussion of certain general characteristics of research of this type and with comments on the academic institution as a specific type of formal organization we turn next to a consideration of particular social science concepts found useful in bringing into focus significant features of the monteith structure finally we discuss the effect of these monteith structural features upon the library project at each stage of its development
CISI	motivation and personality this book was started during the years 1935 1936 and was intended to be a systematic psychology of the older type my effort was to synthesize the holistic the dynamic and the cultural emphases which each one excited so many young psychologists of the time i felt that they were intrinsically related to each other and that they were subaspects of a single larger encompassing whole i felt also that they would make more meaningful my previous studies at the university of wisconsin in comparative and experimental psychology and in biology and neurophysiology furthermore i felt that they would enable me to serve better my humanistic aims
CISI	the motivation to work this book reports the findings from a study of job motivation based on a fresh approach to this problem it is an important study since the analyses and interpretations of the authors suggest that a breakthrough may well have been made to provide new insights into the nature and method of operation of job attitudes the senior authors were well prepared for their task having recently completed a comprehensive review and analysis of the research in this field reported in job attitudes review of research and opinion this review of several thousand articles and books regarding the factors relating to job attitudes and the effect of job attitudes on work performance indicated much disagreement and confusion in the field it appeared that one of the major contributors to this apparent diversity of results was the unstable nature of the subjective data on which studies in this field have been typically based
CISI	an integrated health science core library for physicians nurses and allied health practitioners in community hospitals this core medical library has been revised updated and expanded in the hope of providing a single library facility for the entire health care team items were included in the list on the basis of recommendations submitted by specialists in the pertinent fields the expanded core collection costs about 4 000 space requirements are about 40 linear feet for books 90 feet for journals and 15 feet for reference tools
CISI	gremas   a system for classification and documentation in organic chemistry the authors of this essay were faced with the task of organizing a documentation office in which a large number of publications and patents in chemistry would have to be processed this large collection would be made available to a large group of elements without restrictions to permit a large frequency of use and to maintain this also with increases in file sizes it becomes necessary to limit especially that faction of the task which consists in the retrieval activities paper savings in the retrieval activity are possible only at the expense of greater effort in indexing and by heavier use of technical aids we have taken the second path by consciously applying the principles to a highly detailed faceted classification
CISI	automatic construction of thesauri and of concept systems for dictionaries and subject lists after a synopsis of the relations existing between descriptors and their concepts the epd program called genthes is described the program supports the construction of a thesaurus and its use the relational system corresponds to iso dis 2788 unesco and din 1463 it differentiates however in addition generically related and contiguous terms pertaining to a part whole system characteristics that determine narrower terms against their broader terms are introduced as new relation many types of associations are made available for experimenting the programmed generation of dependent relations reduces the amount of work to one third although ensuring total avoidance of formal errors and logical contradictions even in applying permitted polyhierarchy the program is available in batch mode or in an interactive timesharing version remote genthes the program functions are input logical and formal input checking generation of relations display delete print on line printer and storage on disk genthes is running in vienna on a system ibm 370
CISI	the dk decimal classification   a multi faceted classification backed up by numerical data derived from an aslib analysis of the planned world wide system of unisist the author critically investigates the claimed university of the u d c according to it the so called universal decimal classification proves to be fragmentary terminological aspects are not provided for hierarchical order often is fictitious and the representation of special fields is inadequate for the purpose of reforming the decimal classification a reconstruction scheme is suggested consisting of free facets with the aid of which special classifications can be compiled according to the modular principle
CISI	possibilities for revisions of the dk decimal classification for a number of reasons mentioned it is proposed to reorganize in a new edition the existing udc completely to reallocate the subject fields of the udc main classes according to present day views state of knowledge and priorities and to subdivide these main classes only by subfields of subject fields the specific facets of each field should be represented by a uniform array of special auxiliaries attached to the fields through the technique of interrupted subdivision these should express the following categories 1 theory 2 objects 3 processes 4 attributes 6 order organization 7 relation 8 determination 9 evaluation 5 is left free for the moment proposals for further simplification of the scheme are outlined regarding the general categories the symbols used and the rules for syntagmatic organization taking into account the implications of computer technology possible changes in the layout and editions of a new udc are discussed
CISI	the documentation of documentation independently of the work as a cumulative index and thesaurus a study has been carried out about some information services in the field of documentation the aim was to obtain an overview of the writers work in the documentation area and at the same time to generate the references necessary for a survey about the documentation of documentation nine new information services were considered
CISI	comments about terminology in documentation ii communication and information developing from the definitions of the concept language a terminological represented model of the communication process can be deduced that shows the transfer of meaning between communicator and recipient through communication channels and mediators the distinguished communication structures are communication sequences chains nets and systems with an universal definition of data as fixed representations of facts by means of signs the various meanings of the term information are terminological to differentiate as information information process and informations the theory of signs makes the differentiation of syntactical semantical sigmatical and pragmatical information possible adequate to communication process and system we can determine informing process and information system
CISI	computerized information retrieval services automatisierte information retrieval dienste following an outline of the current trend in information storage retrieval and dissemination this paper provides a description of some of the information services offered at the university of calgary the services include processing of data bases supplied on magnetic tapes the system is briefly characterized as featuring natural text processing selective dissemination of information is directed to users periodically in response to their profiles and retrospective searches are performed on request both in the batch mode feedback from users and system performance are also briefly reviewed
CISI	national aspects of creating and using marc recon records concurrently with the recon pilot project the recon working task force undertook to consider certain basic questions of retrospect conversation that are of national scope first is it feasible to define a level or subset of the marc format that would allow a library using the lower level to be part of a future national network second is it possible to use machine readable records from a variety of sources in a national bibliographic store as a way to reduce the conversion effort on the national level third what are the problems of producing a national union catalog from machine readable records as these studies and the pilot project progressed it also became apparent that there were many practical difficulties in carrying out a large scale conversion project therefore it seemed essential to investigate alternative strategies for recon that might yield broad benefits in a reasonable short time span
CISI	national document handling systems for science and technology this book has grown out of a study undertaken for the committee on scientific and technical information cosati task group on national systems s for scientific and technical information in support of their examination of national document and information systems the emphasis of the study as stated by cosati is as follows 1 initial and primary priority will be placed on national systems relating to scientific and technical documents their handling and the management of such documents specific matters to be reported on will include the current organizational and functional situation in the united states the extent to which known deficiencies are causing a reduction in the potential for technical effectiveness in the united states scientific and technical community the alternatives which are available and economically feasible for correction of these deficiencies and one or more action plans which can be followed by governmental especially including congress and non governmental units 2 secondary attention will be given to development of programs which can be undertaken with government support for identifying analyzing and giving a structure to the total flow of scientific and technical information in the united states
CISI	generalization of epidemic theory an application to the transmission of ideas one of the most fundamental problems in the field of information retrieval is that of determining the circumstances under which it might be necessary to introduce an information retrieval system as an aid to a given population of scientists it is proposed that this problem be examined in terms of the transmission and development of ideas within a population specifically the transmission of ideas within a population will be treated as if it were the transmission of an infectious disease that is in terms of an epidemic process an attempt will be made to indicate the role of information retrieval in the development of such a process
CISI	mathematical approach to the spread of scientific ideas   the history of mast cell research one of the most intriguing problems of modern science is the obscure nature of its own growth indeed there are few notable scientists who have not at one time or another given serious thought to the questions of how their particular science has reached its present state and what will be the course of its future development these questions seem to be of such importance to scientists that they have emerged as fundamental scientific problems in their own right goffman and newill have pointed out that the process by which ideas spread within a population of scientists possesses epidemiological properties and can therefore be investigated as an epidemic process consequently a new set of mathematical tools can be applied to the problem of explaining the nature of scientific development in particular this approach makes it possible to establish the relative importance of past lines of inquiry within a given area of scientific research and to predict the future behavior of existing lines of investigation as well as the emergence of important new ones within the given area the purpose of this communication is to demonstrate this method by applying it to the development of knowledge about mast cells in his recent comprehensive survey of this subject prof hens selye has assembled a full bibliography in which every aspect of the mast cell is dealt with this bibliography constitutes ideal data for the application of epidemic theory to the spread of scientific ideas since it provides us with all the contributions to the subject area from ehrlichs discovery of the mast cell in 1877 until 1963
CISI	dispersion of papers among journals based on a mathematical analysis of two diverse medical literatures two entire literatures relating to research in mast cells and schistosomiasis have been found to differ in almost every respect
CISI	information communication knowledge at the british association meeting in exeter last month professor ziman addressed the section devoted to general topics on the question of how scientific information becomes public knowledge the system of communication he implied is not as rotten as some like to think
CISI	bradfords law and the bibliography of science the rationalization of scientific library systems might be greatly facilitated by the application of bradfords law formulated more than twenty years ago
CISI	bradfods law and library acquisitions bradfords law holds for periodical circulation as well as literature dispersion
CISI	citation indexing for studying science by revealing who has really influenced the course of science the science citation index seems to be a valuable sociometric tool for historians and sociologists
CISI	mathematical approach to the prediction of scientific discovery in the field of symbolic logic at least fundamental discoveries seem to follow patterns suggesting that future discoveries may in some sense be predictable
CISI	scientific information by computer an evaluation of the chemical societys chemical titles information retrieval service compared with a parallel manual search of the literature has shown that at least in certain disciplines more than 90 per cent of the desired information can be obtained this is quite adequate for most commercial and scientific purposes
CISI	library optimum sir  in his recent article b c brookes propounds an ingenious mathematical framework to determine which periodical volumes a library should hold he is careful to point out that the selection will need regular review and revision in case the value of the aging factor a or the contents of the bradford set change from year to year there is as yet very little experimental evidence on the consistency of either such limited evidence as there is suggests that the aging factor is reasonably constant but the position of the bradfod set is less satisfactory the nature conservancy librarians j m weingott and s m penny unpublished have lent me a list of titles cited in the journal of ecology three or more times in 1955 56 and a similar list for 1965 66 there are 150 periodical titles in the two lists but only forty two 28 appear in both of the thirty three titles cited nine or more times in either year only eight 25 attained that level in both and twelve were cited less than three times in the other year the kendall rank correlation coefficient between the two years is 0 18 and not significant there is another major practical problem the article assumes that the data analyzed to obtain aging or utility factors and bradford sets are valid parameters of the relative value of the literature to the readers there is no mention of the type of data to use the reader who sought guidance from the earlier literature cited would find practical techniques described in which analyses of citation frequencies are used to calculate utilities discussed in terms of library use krauze and hillinger have discussed the difference between citations in one article and future citations to that article their work implies a more complex relation between a and u than brookes suggests in any case the validity of citations for forecasting library consultations remains unproven and there are prima facie reasons why the relationship is not necessarily close for example one item in a list of references is often intended to lead to a chain of earlier papers again each citation represents an authors selection from a wider group most of which he has consulted in a library in neither case is there any inherent reason for similarity of age distribution or of pool of titles between the list of citations and the items read by the author or his readers
CISI	effectiveness of combining title words and index terms in machine retrieval searches our experiment was based on volume 24 of nuclear science abstracts nsa which contains about 53 000 citations we used the generalized file management system master control which can operate in either an inverted or a linear search mode the inverted mode uses a table composed of the unique vocabulary contained in one or more data elements along with all record numbers in which each vocabulary word occurs for example an inverted table constructed on titles will have one entry for each unique word of every title in the data base plus the record numbers in which each vocabulary word occurs for example an inverted table constructed on titles will have one entry for each unique word of every title in the data base plus the record numbers in which each word was found in master control a word is defined as any set of characters bounded on either side by a legal separator such as a blank period comma colon etc on the other hand in a linear search mode the data element is compared with the profile word character by character which results in a prohibitively time consuming process for large data bases we chose the inverted table technique because of the large amount of data to be searched individual tables were constructed from the titles of the articles nsa index terms and titles and index terms combined nsa index terms are controlled by the euratom thesaurus as revised for nsa we used two criteria in the study first the questions had to be of real interest to laboratory personnel some of the questions had actually been submitted by other members of the staff to be run concurrently on the same data base on an sdi basis the others were especially constructed by the authors for this experiment second citations obtained were to be considered good or relevant only if they actually pertained to the subject in question otherwise they were to be considered false drops regardless of the number of words matched between the profile and the citation
CISI	method for relating the structure and properties of chemical compounds the structure diagrams of chemical compounds are widely used in the communication of chemistry they are also used in chemical information systems mainly as keys for the retrieval of associated information however some chemical information systems hold property data as well as structure diagrams in machine readable forms if structure property relationships could be investigated easily within chemical information systems then the usefulness of the systems would be considerably increased described below are some results which have been obtained during investigation of structure  property relationships using a combination of regression analysis and some techniques of chemical structure handling used in information systems
CISI	synthesis of situations for a stage of scientific activity synthesis of situations is a stage of scientific activity the necessity and feasibility of a regular professional execution of that stage are argued reasons for incorporating it in the organizational framework of an information system are given the practicability of the concept is tested with reference to some actual problems
CISI	improving the work of a central bureau of technical information the process of integration of sciences and the growing cooperation of creative efforts in the various fields of science and technology intensify the need for interdisciplinary information the prime task of a regional information agency is to meet the information wants of local enterprises an efficient fulfillment of that task presupposes a study of the demand for interdisciplinary information at the patron enterprises in order to set up an appropriate information and reference collection the basic measure of the efficiency of a central bureau of technical information are defined
CISI	specialists requirements for scientific information describes the research in various countries to clear up specialists requirements for scientific information research areas and the results obtained are studied at present no firm conclusions are yet possible as to the effective methods of improving information services things to do are to widen the universe of specialists investigated set up a common methodology study the possibilities of preparing and launching world research program toward this end
CISI	timing data for information processes every r d or design organization should have an efficient information service capable of minimizing time spent on searching and gathering pertinent data generalized data on time spent by r d project staff on information processes is cited suggestions as to the improvement of information activity are offered
CISI	scatter of metallurgical publications in abstract journals the methods that have been used to analyze the scatter of metallurgical publications covered in metallurgiya abstract journal are briefly outlined it has been found out that metallurgiya abstracted 1 546 serials and periodicals in l967 including 290 soviet and 1 256 foreign sources special metallurgical periodicals accounted but for one eighth of the sources which carried 52 9 per cent of the articles abstracted the other 47 1 per cent were scattered through 1 342 journals data on the coverage of the publications of all the areas of the worlds by metallurgiya are given
CISI	concerning the criterion for evaluation of current secondary information the findings are described of a study aimed at determining the prospects and methods for improving the system of current bibliographic information the analysis has shown that the existing criteria for evaluation of special bibliographies scope coverage arrangement speed of announcement etc are inadequate for an unbiased characterization of their exhaustivity and subject contents this hampers a correct choice of the sources of secondary information and leads to duplication parallelisms and loss of information judgements of the leading soviet and foreign bibliographers relating to the problems under consideration are reviewed which are all essentially in favor of a reconstruction of the publishing processes issuing of scientific publications on a world scale and algorithmization of the information processes it is suggested that the first objective of research should be a method of comparative evaluation of periodicals
CISI	on factors influencing the attitude of scientists and engineers towards scientific information the most important objective factors are considered influencing the limits and the depth of information needs of researchers and designers i e the growth of information flow the level of specialization the qualification standard the official position the development rates of scientific or technical discipline in question the teamwork on scientific or engineering projects the language barrier the specifics of narrowly specialized terminology as well as a number of subjective psychological factors like inclination to creative work type of memory the time available methods of sources handling the investigations into and account of these factors are indispensable for raising the efficiency both of information systems performance and the activities of scientific and engineering communities served some statistical data are cited obtained during investigations into information demand patterns for various personnel groups at research and development institutions
CISI	on the problem of economic efficiency determination of scientific and technical information a method for economic efficiency determination of scientific and technical information is suggested
CISI	the psychologic criteria of information selection defines and describes the information selection criteria in the psychological aspects of activity suggestability progressiveness representativeness and the optimal information minimum their specific nature is shown in comparison with other criteria of information selection and their significance for the further study of the psychological problems of informatics is made clear
CISI	nature and essence of information needs the individual collegiate and social information needs are considered in conjunction with the scientific economic and social interests of the community a classification of the information needs is given which takes into account their historic background and subject specialty specifics
CISI	on information needs of different user categories the information need and its main properties are defined classification of information needs in different activities is given relationships between information needs and requests are considered and the process of shaping of information needs and request formulation are traced findings of a study of information utilization by different categories of specialists on the basis of the classification proposed by the author are given
CISI	current awareness bibliographies in the state information system notes that at present the current awareness bibliography of soviet publications which is provided in some form or other almost in all of the areas of knowledge production or culture fails to ensure complete enough information even with respect to directly related literature a set of measures are suggested aimed at a cardinal improvement of the listings in the state bibliography system
CISI	information services for supervisory staff forms and methods in the general practice the management information systems are set aside as a special area the paper elaborates the aspects of selecting forms of management information as well as those of the methods of its preparation and the interrelation between the forms and the methods the basic criteria for this kind of information are defined and the categories or types of likely demands for it are set up examples of management information services are given based on the practice of information centers of czechoslovakia gdr great britain the proceedings of the prague symposium for the analysis of various methods of management information preparation are shortly reviewed the developed sdi system aimed to serve the management is described and also the results of its one year operation are analyzed
CISI	efficiency of information service at a research institute findings of a questionnaire survey discussing the problem of evaluation of the efficiency of an information service at a research institute the paper presents the results of a questionnaire survey conducted in 1968 at an electronics industry research establishment the objective of the survey was to work out improvements of the special information system
CISI	principles of selective information servicing of the different categories of r d staff the characteristics to be referred to in differentiating the r d user needs are defined depending on the administrative status of the user information catered to him must possess the corresponding degree of generalization
CISI	information value of viniti published abstract journals in patent studies methods of analysis of the viniti abstract journals are described as applied for measuring the exhaustivity and speed of coverage of patents the feasibility and efficiency of using the abstract journals of viniti composition of the patent file of a plant subject  or name based patent searches etc the mean time lags in signalization of the ussr patents in the abstract journals are 6 to 7 months british patent    6 to 8 months west german    10 to 12 french 12 and us    12 to 13 months some improvements of the abstract journals as source in information on latest world inventions are suggested
CISI	a system of documentary information flow analysis science journals the paper describes a system of analysis of primary science journals from the standpoint of the efficiency of their use as sources for abstracting in conjunction with punched cards and electronic computers the procedure employed to process the file of science documents is outlined the program of analysis provides for obtaining statistical data on the regularities of the concentration of special profile periodicals and the scattering of the interdisciplinary sources as well as the characteristics of the systems of relations existing between the individual series of the abstract journal
CISI	the pattern of the information needs of an r d institute and the system for meeting them the functional structure of a research institute is analyzed s well as the functional structure of its information services the latters development the overall subject pattern of the creative interests of the institute and the system for meeting these
CISI	on informal processes of science communications the paper makes a discussion of major theoretical and experimental studies of the role of informal processes of communication in science the author holds that the system of scientific communications is based on formal processes founded on scientific and technical literature including the primary and secondary sources whereas the informal processes in which scientists play the leading part and which have no institutionalized and permanent interactive mechanisms are also very important but auxiliary the specific features of the informal processes and their interaction with the formal processes are analyzed in detail recommendations towards efficient use of the positive aspects of informal communications for raising the overall effectiveness of scientific communication system are offered
CISI	state system of scientific and technical information results and prospects some results of state information system activity for the past year are considered disadvantages in work of scientific and technical information organs of different levels are noted and tasks for further improvements of information activity for 1973 year are defined
CISI	social and economic premises to the development of an information system more attention should be given to the creative personality and better conditions ensuring the adequate information support to the more capable and gifted scientists holding key positions in science should be created the relationships connecting creative activity and informational activity are analyzed certain general conditions of scientist information interaction are examined as affecting the informational activity of a scientist the specifics of the development of a creative personality in conjunction with the growth of teamwork in research and development and the concomitant change of the interrelation between the user and the information base are investigated
CISI	analysis of information flows in shipbuilding and the allied fields parameters of information flows are identified as reflected in vinitis abstract journals carrying materials in shipbuilding and the related fields the objective of the large scale analysis of these flows is to support the development of an automated system of ship design and the industrys sci tech information subsystem more than 1400 periodicals and serials have been identified that are relevant to the field the file of secondary publications in the field carried by viniti abstract journals since 1956 amounted to 185 000 items
CISI	informational reviews in the age of information crisis a critical analysis is given of existing classification schemes for reviews the author proposes to distinguish between two main review types orienting and informative ones the importance is stressed of informative analytical and abstracting reviews which contain new information under the conditions of information crisis being interpreted as overproduction of documents rather than new knowledge
CISI	pragmatic aspects of scientific information postulating an interrelation between semantic and pragmatic properties of scientific information the author formulates the information value function as depending on three arguments subject information and purpose thus this value is a composite of subjective and objective factors possible classifications scientific information values are discussed a methodological analysis of three approaches to the mathematical notion of information value is given and by analogy some propositions concerning measurement of scientific information value are expressed
CISI	mathematical model of classification theory sets of objects possessing specified characteristics are studied the similarity and equivalence relations between objects are established and explored a canonical system of characteristics is derived similarity and commonness measures of the subsets of objects are investigated the implications of those notions for the problem of retrieval classification are pointed out
CISI	methods for thesaurus generation the author gives a general definition of the ir thesaurus and outlines its inner structure he describes a procedure of accumulating the body of keywords which is required to compile the vocabulary of descriptors an attempt is made to determine how the rate of keyword accumulation depends on the number of abstracts titles processed and in what way the volume of descriptor vocabulary is related to the number of documents indexed general rules are given for lexicographic processing of the keywords accumulated and for compiling of the descriptor vocabulary the algorithm has been constructed which is designed to generate the article of each descriptor in the thesaurus to construct this algorithm the author analyzed the results of word association tests and selected 5 most important types of paradigmatic relations he formulates the basic rules for translation of the texts describing the main subject content of the documents and of the users requests from a natural language into the ir language of descriptors the block diagram of algorithm for translation of these texts is also given in conclusion the author describes general principles of lexicographic editing of the above mentioned texts
CISI	axiomatic relevance tolerance theory sets are considered on which a symmetric and reflexive relation called tolerance similarity is defined the structure of such sets is explored a classificatory theorem is proved stating an isomorphism of embedding of such sets in a model space r the properties of particular sets for which the similarity relation has been defined are investigated
CISI	a grammatical elements in a descriptor language for an information retrieval system the results are described of research and development activities of the mechanized information retrieval laboratory of the niitekhim research institute aimed towards creating a descriptor language for an information retrieval system in the field of chemistry and chemical engineering the objectives of an optimum reduction of retrieval noise and maximum recall have required the introduction of grammatical and transformational devices into the language the former condition is provided for by a matrix notation of document search patterns and requests while the latter condition is met with the help of the transformational devices of the language examples of search requests and patterns are considered which illustrate the resolution of the grammatical and transformational devices being developed these are said largely to eliminate subjectiveness in assigning relational factors in search patterns and requests the relevancy criterion is formulated a retrieval algorithm based on this criterion has been compiled experimental searches were conducted on a minsk 22 computer the results were analyzed to evaluate the grammatical and transformational devices and to verify indexing principles devised for the automated retrieval system under development factors of silence are discussed as well as the contribution of the grammatical and transformational devices to reducing noise and enhancing recall
CISI	the outlook of cybernetic and computer applications in the national system of scientific and technical information the paper outlines the prospects of applying cybernetic methods to the analysis and synthesis of information processes in a national systems of scientific technical information and in information agencies which are considered as big systems of differing ranks the main stages of research along these lines are investigated
CISI	analysis of some regularities of the flow of engineering information some theoretical propositions are considered with respect to the flow of engineering information with the purpose of drawing practical conclusions for the editing of information announcement publications
CISI	rank distribution in scientific information sets a study has been carried out dealing with the development of science in terms of sets of scientific and technical data it is assumed that the characteristics of a rank distribution provide unbiased data to reflect the process of differentiation of sciences rank distribution over the sets of scientific and technical information are characterized by the formation of a kernel of the distribution and of the problematic nature as a phenomenon a mathematical model is considered to be used for computing the values of the kernelness and problematicity of a rank distribution
CISI	some aspects of developing and studying a descriptor information language for general technology the methods and results of an endeavor to develop an information retrieval language for automatic retrieval systems meant for handling a polytechnical document collection are described the descriptor dictionary includes general and special terms both single word and phrase terms which is conducive to higher recall and relevance it comprises a classified index and a lexico semantic index as well as tables of generic relations the size of the dictionary is 5 542 descriptors and 3 073 keywords the indexing procedure includes analysis of document content and its characterization by keywords elicited from natural text and creation of the search pattern using the descriptor dictionary the techniques are described which are applied to analyze the documents into semantic aspects that constitute the elements of the formalized model of a documents condensed content the procedure employed to translate a text into the retrieval language comprises selection of words both from the title and the body of the document main principles for retrieval efficiency determination using mathematical statistic methods are given tests on multi subject collections show a probability of 85  recall and 70  relevance at a standard deviation of 25 these findings have been corroborated by the results of the basic experiment on a file of up to 2 500 search patterns using 42 requests among the factors of losses there are the poor quality of abstracts into cards and the absence of a single abstracting procedure it is proposed that abstractors should be in future charged with writing abstracts in keywords and ultimately in the descriptor language the experimental results attest to the feasibility and practical sensibility of creating a multi disciplinary information retrieval system to be based on a broad scope descriptor dictionary and on the suggested methods for document and request indexing
CISI	a contribution to the theory of the systems of information flows certain structural properties of information distributions are explored as well as the gnosiological aspects of informational relations and the capabilities of an information retrieval system based on information distribution methods mir
CISI	evaluation of indexing and a technique for formalized search request statement a method for evaluation of indexing is expounded the feasibility is examined of using marked documents instead of requests called the beacon method a m algorithm for formalized statement of search requests is described and exemplified by an information retrieval system in the nitrogen industry
CISI	evaluation of information loss probability in indexing a practical technique is proposed for assessing the losses of relevance documents on the basis of probabilistic methods and for entering marked documents into the system
CISI	free information of a social system the structure of the information field of a social system is examined analyzing the processes of formation of scientific concepts the functional structure of the information field is shown to reflect that of human brain it is established that the effect of the wash off of noise out of the information field with the course of time leads to concentration of the real socially valid free information in publications covering finite time spans the interrelations within the service user system are shown to be essentially different for scientific vs industrial information supplies
CISI	creating an information language on the basis of semantic text analysis discusses the possibility of setting up an il with a development grammar and logic capable of solving problems of diverse informational complexity documentary search data search automatic text condensation automatic translation the semantic language ekho is proposed as a language of this kind its structure is described and its potentialities for information are followed
CISI	aspect abstracting a new technique the new technique has been developed on the basis of an analysis of the present methodological requirements laid to abstracting and a study of textual records as modelling the real world and reflecting the logic of research aspects of meaning have been adopted as the invariant unit characteristics of a documents purport semantic adequacy and semantic equivalence are proposed as criteria to evaluate abstracting precision and exhaustivity the aspect based approach could be likewise applied to indexing of documents and information requests if introduced into the practices of information analysis this technique is expected to raise the standard of abstracts and the efficiency of document oriented retrieval
CISI	algorithmic procedure for compiling a list of keywords and key phrases by the abstracts in fizika abstract journal the algorithmic procedure is based on a linguistic approach it serves to isolate key phrases from the abstracts of the fizika abstract journal recognizing set phrases with the aid of linguistic rules the feasibility is demonstrated of a completed formalization of the process of eliciting key phrases for a descriptor dictionary
CISI	debugging the technologies of an automated irs in electrical engineering a case study the experience gained with adjusting and debugging the technologies of automatic document indexing at an electrical engineering reference information centre are outlined the procedure applied to document handling is compared to that of processing an equipment part in industrial production and it has been designed in the corresponding terms
CISI	thesauri in informatics and in theoretical semantics the possibilities are discussed of a universal definition of the concept of thesaurus thesaurus structures and construction methods are considered
CISI	information retrieval learning the statement of the problem and the results of an experiment in automatic choice of retrieval criterion are described the problem of criterion choice is interpreted in terms of a pattern recognition problem the criteria chosen as a result of learning are considered as well as the retrieval noise and losses recorded in searches using these criteria the experiments suggest such limit noise level which is not liable to any substantial further reduction the efficiency of choosing a criterion through learning is discussed the relationship between information retrieval learning and nondeductive logic is investigated
CISI	an invisible college for the study of experiment planning the activity of an invisible college is surveyed formed around the interdepartmental laboratory for statistical methods of the moscow state university in the area of experiment planning the analysis of publications by the members of this college was made referring to the science citation index 1966   1967 a graphical representation of the invisible college is suggested comparative data on publications are cited and various schools in experiment planning for basic and applied research are analyzed
CISI	data retrieval systems specifics and problems the essential differences between data retrieval system and document retrieval systems are considered the notion of fact is discussed analyzing the influence of the definition adopted on the structure of a data retrieval system a proposition is advanced that a factographic jrs is a rudimentary but indispensable form on the way to a logical information system the latter type of system by a capability for automatic analysis of input data and synthesis of new information the problem of the information retrieval language for data retrieval system is discussed as is its machine organization intricately tied up with the specifics and functions of a system of that kind
CISI	logic of classification formal definitions of characteristic taxon hierarchic and combinative systems of characteristics are given establishing the elementary properties of these concepts and their interpretations in conventional classifications systems
CISI	relevance and pertinence the correspondences of documents to information requests and to information needs are investigated as a special instance of informational correspondence of interrelated objects of a differing nature in terms of the concepts of relevance and pertinence
CISI	the language of an polytechnical automated information retrieval system the principal design features are described of an information system using the natural language and a descriptor language thesaurus organization relevance criterion indexing procedure experimental estimates of the information language and parametric information processing techniques
CISI	on the symbolic nature of classifications the nature of an arbitrary classification is considered from the viewpoint of its sign function the structure of the taxons described by a given classification is treated as the referent the denotate the formation of taxons is shown to be connected with the preliminary arrangement of the subject area into a classification field the classification concept is connected with the structure and nature of the classification characteristics a typology of classifications is introduced distinguishing them by intensionality or capacity for expression of the concept independent of the subject area differences are pointed out that exist between the classificatory and thematic relationships and the correlations between these two groups of relationships are analyzed
CISI	algebra of classification two alternative concepts of isomorphism of classification are examined it is shown that with the accuracy of up to isomorphism the structure of a classification is characterized by a certain semigroup for an important type of classifications the algebraic structure of these semigroups is completely characterized by the relation of order on the set of generants the case of perfect order on the generants corresponds to hierarchical tree classifications the case of incomparability of the generants corresponds to facet classifications all the other cases are intermediate between these two types of classification
CISI	science on science   introduction to a general science of science this book generalizes world and soviet experience of science gives original representation of science as informational process which allows one to use quantitative methods in scientometrics analyzes extensive data on the experience of formulating scientific potential and organizing scientific work formulates general principles of organization management and disposition of modern scientific centers in particular methodological problems of planning and prediction of science are examined
CISI	a study of six university based information systems a methodology for categorically describing computer based information systems was developed and applied to six university based nsf supported systems the systems under study all operate as retail information centers primarily serving campus communities by accessing large commercially available data bases using 3rd generation computer configurations the systems vary in design philosophy mode of user service transferability characteristics and operational status a summary matrix is included
CISI	automatic indexing a state of the art survey of automatic indexing systems and experiments has been conducted by the research information center and advisory service on information processing information technology division institute for applied technology national bureau of standards consideration is first given to indexes compiled by or with the aid of machines including citation indexes automatic derivative indexing is exemplified by key word in context kwic and other word  in context techniques advantages disadvantages and possibilities for modification and improvement are discussed experiments in automatic assignment indexing are summarized related research efforts in such areas as automatic classification and categorization computer use of thesauri statistical association techniques and linguistic data processing are described a major question is that of evaluation particularly in view of evidence of human inter indexer inconsistency it is concluded that indexes based on words extracted from text are practical for many purposes today and that automatic assignment indexing and classification experiments show promise for future progress
CISI	neighborhood information centers a study and some proposals our point of departure is a study of the feasibility and desirability of adapting the british citizens advice bureau cab plan to the united states carried out with the financial support and cooperation of the ford foundation we conclude that the british cab pattern while creative richly implicative and a major source of valuable guidance if merely duplicated would not make the optimum contribution to the current american scene we find overwhelming evidence that new information advice referral provision are necessary localities need and want neighborhood information centers nics we find promising beginnings and a number of attractive possibilities emerging out of the somewhat different efforts by a number of federal agencies local government and local voluntary groups however no one of these provides auspices for all the needed functions in accord with qualities which we find to be essential
CISI	networks for research and education responding to the heightened interest in the possibilities of networks and reflecting its own continuing interest in improving the use of new technologies in research and education the national science foundation in 1972 announced the mounting of an expanded research program to explore the resource sharing potential of a national network in support of research and education the nsf was well aware of the obstacles and uncertainties and it knew that although shareable resources and pockets of relevant information and experience existed many of the people who should be involved in planning were not currently informed or discussing the possibilities with one another
CISI	a core medical library for practitioners in community hospitals in a ongoing study designed in part to evaluate and encourage continuing education programs in community hospitals postgraduate medical institute pmi has determined that there is need for guidance in the area of medical library development reports from pmi physician consultants who visited more than 40 community hospitals indicate that medical library facilities are generally poor and infrequently used by physicians the basic weaknesses of these libraries fall into four categories inadequate collections inadequate personnel inadequate space and the absence of any practical indexing system to facilitate use of collections that do exist failure to deal with these problems does not reflect lack of interest but rather lack of stimulation to do so and absence of any concerted source of guidance in response to requests for such guidance pmi has undertaken a community hospital library development project in co operation with the new england regional medical library service nermls at the francis a countway library of medicine this report is concerned with the first phase of this project   namely the formulation of a list consisting of a minimal number of textbooks and journals that can function as the core for a medical library explanatory letters and questionnaires were sent to 400 specialists representing 50 areas of medical practice including the basic sciences the specialists chosen from regions throughout the country were requested to recommend two textbooks and two journals in their area of special interest that they considered to be the most basic and fundamentally useful for practitioners it was also requested that recommendations be made in order of preference
CISI	the new industrial state during the fifties and sixties it had become customary to depict the economic system of the united states along with its european and japanese counterparts as an accomplishment unique since the creation this volume departed from the accustomed cheering it is my impression that the adult reader was always more skeptical than the economists of the neo keynesian nirvana economic life was not meant to be that easy and perhaps some sensed what i here urge that what was called success was less what served the individual than what served the goals of great industrial and military bureaucracies which had come the economic myth notwithstanding to comprise so large a part of the economic system still who could tell that a herald of such news would be welcomed   or even heard
CISI	the new librarianship a challenge for change among the avenues explored were the following the attractions the field holds for those now in it and those who might be drawn to it the personality of those in the occupation and in its various subfields and work roles the characteristics and perspectives of the institutional administrators supply and demand facets of the manpower problem organizational relationships in libraries and information centers library education as a professionalizing and socializing force and the implications of network development for manpower planning central to the study rationale was the notion that librarianship should be viewed not as a static institution committed solely to traditional objectives but as one with the capacity to be responsive to changing environmental requirements it was hoped that from the intelligence gathered from these inquiries certain of the significant dimensions of the fields manpower concerns would be illuminated and proposals to influence future development would be drawn thus while the investigations were in the nature of more basic research their ends were committedly pragmatic
CISI	new patterns of management this volume is intended for persons concerned with the problems of organizing human resources and activity it is written especially for those who are actively engaged in management and supervision and for students of administration and organization it presents a new theory of organization based on the management principles and practices of the managers who are achieving the best results in american business and government it draws also upon research done in voluntary organizations to maintain a relatively consistent orientation the focus of this volume is largely on the problems of business enterprises people interested in other kinds of institutions such as schools hospitals labor unions professional and voluntary organizations should however experience no difficulty in applying the general principles of the theory to their organizations
CISI	unintentional duplication of research a survey revealing instances of belated discovery of information in the literature leads to an estimate of what duplication costs in a letter in new scientist vol 19 p 148 the rate of duplication of research among scientists was said to have been estimated at about 10 per cent the first systematic attempt to assess the size of this problem carried out by the aslib research department suggests the actual figure is more than double this and the consequent cost to the nation to be measurable in millions of pounds we put questions to 647 scientists engaged in industrial academic or government research including chemists physicists biologists psychologists and mathematicians one question was have you during your current research discovered in the literature information which you wish you had had at the beginning of your project to this 144 of them 22 per cent replied that they had many had made more than one such find so that the total number of instances was 245
CISI	non book materials the organization of integrated collections this book presupposes a knowledge of book cataloguing and basic cataloguing principles the dewey decimal classification 9th abridged edition sears list of subject headings 9th edition and a list of canadian subject headings together with a form of simplified cataloguing found in many school libraries have been used on the sample cards it must be emphasized that the subject analysis systems chosen by a particular library for its print collection should be used for all media because of its school library orientation this book distinguishes between essential and optional elements on the catalogue card libraries which require detailed cataloguing will consistently list these options and may wish to augment the description of materials in the collation and in the notes items necessary for a minimum description and for a complete description will be subject to further study prior to the next edition of this work
CISI	nonbook materials the organization of integrated collections many segments of society are recognizing that access to information is a vital and fundamental contemporary need to provide optimum access it is essential to be able to retrieve information in whatever physical format it is found such retrieval requires the development of cataloguing codes that will handle all media including diverse kinds of audio and visual materials to be most effective these cataloguing guidelines should be acceptable on an international level and should have the support of professional organizations most concerned with these problems
CISI	nonparametric statistics for the behavioral sciences in this book i have presented the tests according to the research design for which each is suited in discussing each test i have attempted to indicate its function i e to indicate the sort of data to which it is applicable to convey some notion of the rationale of proof underlying the test to explain its computation to give examples of its application in behavioral scientific research and to compare the test to its parametric equivalent if any and to any nonparametric tests of similar functions
CISI	a study of information requests for scientific research and design this paper describes methods of studying information requests on source information analyzes results of questionnaire distribution on the basis of the questionnaire answers a card file of the subject requests and list of requests on source information was formed since the study these requests determines the content and purpose of the information process the author suggests that the study of requests be the first phase of information process
CISI	formulation of information requests this article presents the results of a study of the information requests of inquirers it was elucidated that engineers spent an average of 10 hours per week in search of needed information most valuable sources of information are theoretical journals the study showed that stable life of theoretical journals equals about 12 years and information journals about 5 6 years some recommendations were formulated on how to construct a reference information collection
CISI	definition of active stock this article considers the question of defining active stock for the electrical engineering field significant attention was paid to including specialized journals using methods which calculates number of bibliographical references made in bulletins and bibliography at the end of the articles with bradfords distribution reliability of this method is discussed
CISI	principles of studying of information requests earlier publications on the study of information requests consisted of statistical listing of the most usable sources of information lately there is an increasing number of publications which consider the methods for studying information requests analysis of these publications shows that we can discern two basic tendencies studying subfield groups of researchers and groups of researchers classified by topical information sources some attempts were made to study information requests in connection with creative processes psychology of creativity and also to establish the purposes of information retrieval and scientific sources of information
CISI	characteristics of text structure complexity this article considers the conditions under which v ingves theorem on the depth of syntactic structures is applicable the relations between graphs of generative phrase structure and phrase government are studied new operators for the generation of syntactic structures are introduced
CISI	methodological problems of scientific technical literature typology two causes for inconsistency between a primary document is content and form are examined 1 inconsistency between document structure and structure of its information 2 insufficient development of theories of scientific and technical literature in particular the typology of primary scientific documents it is suggested that the concept of genres of scientific technical literature be introduced based on the degree to which the material is generalized five basic genres are examined technical reports articles monographs text  books and reference works the practical application of a typology of scientific and technological literature is shown to be possible
CISI	some problems of scientific information theory examines aspects of scientific information theory connected with assessing the semantic characteristics of information statistical nature of texts and economic factors the significance of automatic translation methods is considered from the point of view of the general problems of information science
CISI	on basic features of information retrieval language for information retrieval by title part 1 presents the basic features of variants of an informational language designed for searching titles of publications in the field of synthetic organic chemistry the classification of terms from natural language and the specifics of translating them into information language are discussed a method for selecting the synthetic means of informational languages is developed and the criterion for semantic correspondence and search algorithm is briefly described experiments which were conducted with 3 variants of the language developed are discussed conclusions are drawn on the benefits of the languages for searching recommendations are made regarding their field of application
CISI	the thesaurus and some methods of its construction part 1 it is suggested that the thesaurus be considered a hierarchical system for classifying factors the problem of automatic construction of thesaurus is posed a formal description input and output of this problem is given a series of classificational concepts is formulated
CISI	on basic features of information retrieval language for information retrieval by title presents the basic features of variants of an informational language designed for searching titles of publications in the field of synthetic organic chemistry the classification of terms from natural language and the specifics of translating them into information language are discussed a method for selecting the synthetic means of informational languages is developed and the criterion for semantic correspondence and search algorithm is briefly described experiments which were conducted with 3 variants of the language developed are discussed conclusions are drawn on the benefits of the languages for searching recommendations are made regarding their field of application
CISI	issues in the informational analysis of documents in scientific process and primary scientific documents there are objective characteristics which allow the accurate and unambiguous reflection of the form and content of primary statements n the informational analysis of their secondary pattern using these characteristics allows one to develop a model of standardized bibliographic and abstract document description and minimize subjectivity in information analysis the objective characteristics of form and content of documents and corresponding elements of bibliographic and abstractive description must be based on application of classification schemes for each characteristic there must be a corresponding scheme of particular structural complexity
CISI	new tasks of information services and specialists training problem state of the art in reference information servicing and training of specialists for information establishments is described
CISI	prospects for primary and secondary scientific publications the problems facing specialized primary and abstract journals in the present environment of rapid publication growth are discussed an acceleration of publishing and higher information capacity of the journals can be achieved via depositing and up to date editing methods the situation of abstract journals in the context of growing differentiation of scientific and technical disciplines is depicted
CISI	analysis of biological publication growth on the basis of periodical sources the dynamics of the growth of biological publications is investigated an analysis of this growth reveals certain uniformities in the evolution of scientific communications which depend on the field of biology and discloses the uneven rate of development in the individual fields it is concluded that the specialty is a major factor to be taken into account in defining the volume of information necessary for a specialist
CISI	the emerging science of information discussing whether it is possible and sensible to build up a general science of information the author comes to the conclusion that all the necessary prerequisites to formation of this new discipline to be termed informology are ripe the structure of informology and its interrelationships with informatics are investigated a diagram showing the place occupied by informology within the overall framework of sciences and its inner structure is presented
CISI	some aspects of subject acquisition and detailed subject retrieval of patent information aspects of subject acquisition and retrieval of patent information are discussed a patent information service system is conventionally separated into two parts a subject acquisitions system designed for stock acquisition and search file building and a detailed subject retrieval system designed to deal with specific user requests the performance of both systems is analyzed using patent classifications as examples the tasks of classification research in relation to subject acquisitions system requirements are formulated
CISI	problems of compatibility of information on retrieval systems and requirements to the language of an information network the objectives of information network design are stated analyzing the basic operations carried out in conjunction with system interaction within a network the notions of information network and information retrieval system compatibility are discussed a sine qua non of network functioning is an integrated retrieval language descriptor languages appear to be most promising for broad profile document files a descriptor language is conceived as a complex comprising a thesaurus for terminology control classifiers for nomenclature control and the working dictionaries of the system patrons which comprise fragments of thesaurus and classifiers plus narrowly specialized terms as conforming to the file and user needs concerned requirements to a thesaurus as the core of an information network language are considered
CISI	a statistical analysis of published articles on electrical and power engineering a statistical analysis of articles published in electrical and power engineering serials and periodicals is given the results have been used to refine the quantitative formulation of the zipf law the computational method used can serve as a prototype for analysis of abstract journal like publications
CISI	a probability distribution in information flow systems the paper treats the probability distribution in information flow systems and presents the analysis of a statistical distribution model called the hyperbolic ladder and of the consequences following from this model which were revealed in linguistics zipf theory of scientific information bradford and in science of science lotka etc the identity of the mathematical essence of various distributions investigated by many authors on their own objects of study is shown the link is considered between the basic probability distribution and some problems studied in the modern mathematical theory of information examples are presented of the use of distribution regularities in various systems analysis
CISI	a standard format of progress reports on scientific technical information a standard format of progress reports is suggested based on the experience of research institutes and drawing offices the schedule of reports and each of their sections proceed from the need for maximum noise resistance of reports as used by various categories of users and giving an exhaustive description of final and intermediate r d results the author shows that the difference between the notion of information value and of document value dictates a specific approach to organization of the flows of documentary information duplication of data in documents of various kind and to development of the logical format and literary style of scientific documents
CISI	syntagmatic relations between descriptors syntagmatic relations sr are defined as connections between words that are established aposteriori and combine these words into phrases and sentences the lack of means for recording sr in descriptor languages results in a reduction of retrieval precision at present roles and links and the evaluation of the extent to which these devices are used are the major devices used for the description of sr between descriptors in documents search patterns an analysis of published results of experiments testing the performance of roles and links in 176 descriptor retrieval systems operative in the usa suggests the conclusion about a poor performance of roles as a precision device an increase of 10 percent in precision with the aid of roles is accompanied by a 10 percent reduction of recall links provide for approximately the same increase of precision the author states the general requirements to a simple and flexible grammar for descriptor languages and show that the approach the suggest ts has been partially implemented in the information retrieval language for radioelectronics and computer technology developed at the institute of cybernetics of the ukrainian academy of sciences in kiev and in the syntol france
CISI	techinical bibliographies in metallurgy the article presents preliminary results of an analysis of current technical bibliographies specifically in the field of metallurgy conducted at the chair of technical literature leningrad krupskaya institute of culture the bibliographies have been analyzed in terms of selection quality and coverage attention was focused mainly on permanent publications based on rich experience and elaborated procedures metallurgiya abstract journal is shown to hold the lead among chief world publications in metallurgy in respect of scope coverage and depth of indexing
CISI	on rational structure of a science journal article a rational scheme for a scientific or technical article is proposed which is bound to improve its informativeness by purely formal means
CISI	psychological problems in informatics and the prospects of their solution the psychological problems arising in creating and utilizing scientific and industrial information are stated the subjects of study of the information science labour psychology engineering psychology and psycholinguistics are considered the analysis suggests the conclusion that a new trend of psychological research as emerged   the psychology of informatics
CISI	topical aspects of informatics to date a definition of informatics is given its method and subject are discussed and the aims and prospects of the science are outlined the author holds it to be an important achievement of the research in the fields of informatics and the science of science in the past few years that information flows have come to be viewed as system with definite and understandable regularities which should be taken into consideration when working out information retrieval system
CISI	a notation for coding organic compounds a notation for coding organic structures has been developed which provides for very simple and rational rules of coding the common cyclic fragments the conventional unit used in coding regular structures is benzol ring and the skeleton of the regular condensed system is coded using a sequence of even and odd integers the set of rules for coding regular systems might be used as component of a universal notation for organic compounds the code offered by the author is designed to cover an important and broad class of compounds with conjugate bonds and it can be used within the framework of a specialized computer based information retrieval system in the capacity of both the input and the internal machine language
CISI	the origins of the information crisis a contribution to the statement of the problem the different explanations of the nature of the information problems now facing science and their causes are cited and shown to be debatable it is necessary to give a definition of information crisis this widely used concept in informatics and the science of science the author suggests one such definition which reflects the specific historical nature of the possible manifestations of the crisis the cumulativistic concept of the progress of science is criticized as it rules out the possibility of finding the true causes of the information crisis the major cause is asserted to lie with the nature of the contemporary social production an approach to studying into the origins of the problem is suggested
CISI	the bibliography of operational research in his book on documentation 1948 the librarian s c bradford discussed certain regularities in the pattern of distribution of articles on a particular subject over different journals he gives as examples the distributions for geophysics from 1928 31 inclusive and lubrication for 1931 to june 1933 inclusive the typical picture is one in which to a bibliography covering a certain short term of years a few journals contribute a large number of articles more journals contribute fewer and so on in a monotonic sequence ending with a large number of journals contributing one article each patterns of this kind have been observed by several authors but bradford was the first i think to advance an explanation of the effect in bibliographical terms
CISI	operations research implications for libraries library operations in recent times have been characterized by a great increase in complexity the rapid expansion of collections both in size and scope the great variety of forms taken by items that now must be housed in the library and the growth in expectations among library users are among the factors that have contributed to this complexity in this setting managerial decision making in the library has become an unenviably difficult task furthermore the new technologies and new techniques which offer great opportunities for library planners and managers make even more difficult the use of traditional intuitive approaches it is reasonable to ask whether techniques such as operations research o r that have proved valuable in similar situations for business and government might not also be of service in libraries
CISI	compact book storage in libraries a method is developed for optimally shelving inventory items by size with particular reference to large library collections the area presented by n 1 distinct shelf heights is minimized for any collection that can be characterized by an item height distribution when item height is continuous the necessary conditions for the extremum are recursive in the optimal shelf heights and the solution reduces to a simple computational search for certain distribution functions as demonstrated in the example an additional recursive relation between the solutions for different n further simplified the computation considerable geometrical representations of both the model and the solution method are presented the maximum increase in storage capacity can be expressed generally as a simple function of the mean and the maximum item height
CISI	experimentation in the theory of linguistic description the principle tool for the study and description of natural languages used in this book are working models of the type sense   text the similar model for a given actual language is a completely organized sum of rules whose purely mechanical application should ideally allow one to 1 go from the given text in the language being studied to the formal description of the sense of that text i e to its semantic representation semantic notation 2 go from a given meaning i e from a given semantic representation to a text in the language being studied which will convey the same meaning if the proposed meaning may be expressed in more than one way then all the appropriate synonymous texts should be constructed
CISI	organization and environment managing differentiation and integration what organizational characteristics are required to deal effectively with different external market and technological conditions this is the central question which this book addresses such a question is quite different from the central theme of most earlier organizational studies which have tended to focus on the question of what is the one best way to organize irrespective of the external environmental conditions facing the business in this important respect this study breaks new ground nevertheless it draws heavily on earlier studies in the field of organization behavior at harvard business school and elsewhere as well as the related literature of the behavioral sciences the authors not only report the findings of a comparative study of ten organizations with different levels of economic performance in three distinct industrial environments but also use these findings to unravel some of the apparent contradictions in current organization theory a discussion of the implications of these findings for the design and administration of large organizations in relation to their specific market and technological environments is also included
CISI	organizations this book is about the theory of formal organizations it is easier and probably more useful to give examples of formal organizations than to define the term the united states steel corporation is a formal organization so is the red cross the corner grocery store the new york state highway department the latter organization is of course part of a larger one   the new york state government but for present purposes we need not trouble ourselves about the precise boundaries to be drawn around an organization or the exact distinction between an organization and a nonorganization we are dealing with empirical phenomena and the world has an uncomfortable way of not permitting itself to be fitted into clean classifications authors are often convinced that the particular subjects with which they are dealing are more significant than the world has acknowledged we cheerfully make this claim for organization theory however much organizations occupy the thoughts of practicing executives and administrators and however many books for these practitioners have been written about them the theory of organizations occupies an insignificant place in modern social science most current psychology and sociology textbooks do not devote even a short chapter to the subject of formal organizations the handbook of social psychology lindzey 1954 contains chapters on small groups mass media industrial social psychology with only passing references to organizations leadership and voting behavior there is no comparable chapter on formal organizations and only scattered reference to them throughout the text
CISI	organizations in action social science bases of administrative theory this book might be considered a conceptual inventory this is a departure from the recent fashion of conducting propositional inventories which assumes that important relationships have already been explored berelson and steiner 1964 i assume merely that the concepts relevant to important relationships exist and once having identified some i hope to generate potentially significant propositions we lack the systematic evidence that eventually must come but there are illustrative studies cited to indicate that the propositions which are neither time  nor space bound i assume that there are differences among organizations and hope to account for some of them but i also assume that there is not a one  to one correspondence between significant organizational differences and the typical categories of business government medicine and education likewise i believe there is not a direct correlation between the academic disciplines and useful categories of complex organizations
CISI	organizing nonprint material the object of this book is to establish a means for organizing collections of nonprint material so that greatest efficiency can match most effective service no lesser goal is worthy of consideration in discussing the problems of organization the examples of material have been used to explain differences in treatment that can be made responsive to the needs of the community that the library serves nonprint material is a vital part of a modern library of whatever type school libraries have made the greatest use of the material so far to the point of becoming media centers but the avalanche of information is not only in print form and the need for information may often be satisfied only by nonprint material
CISI	basis of informatics informatics is a new scientific discipline studying the fracture and characteristics of scientific information the regularities of scientific information activity its theory history system of methods and organization the book formulates subject and method of scientific information theory gives specification of different kids of documents as sources of scientific information sheds light on the methods and forms of analytical synthetic document processing expounds basic principles of information retrieval and ways to mechanize and automatize it describes methods and resources of document copying and reproduction
CISI	basis of scientific information the present monograph is one of the first attempts to expound the basis of scientific information its theory systems of methods and organization the monograph formulates subject and method of scientific information theory gives specification of different kinds of documents as sources of scientific information sheds light on method and forms of analytical synthetic document processing expounds basic principles of information retrieval and ways to mechanize and automatize it describes methods and resources of document copying and reproduction
CISI	out of the dinosaurus the evaluation of the national lending library for science and technology the establishment of the national lending library for science and technology nll has been one of the most significant events in british librarianship in the twentieth century this book attempts to trace the development of the library up to its merger into the impending british library and to describe the philosophies which shaped its policies and services i hope that the book will be of value to british and overseas librarians as a case study of the development of a national library and also to students of librarianship and information work in that it may help them to appreciate the context in which the library has evolved and in which it now operates
CISI	an overview of operational ballots ballots bibliographic automation of large library operations using a time sharing system is an on line system that assists book processing in the acquisition and catalog departments of the stanford university libraries the library staff use video cathode ray tube or crt terminals to perform a variety of functions involving several computerized files and as a result of this on line activity the system updates the files and uses data from them to print the library outputs overnight
CISI	compaction of names by x grams this paper presents a method for compacting proper given names for computer storage the method presented uses x grams which are combinations of from one to eight letters rather than spelling names letter by letter they are spelled with x grams an algorithm as been implemented in a computer program and used to obtain sets of x grams for two large 42 165 and 43 875 given name samples using the x grams obtained it was possible to represent the names from one sample in 1 78 bits per original character and in 2 1 bits per original character in the second sample
CISI	comparative effects of titles abstracts and full texts on relevance judgements twenty two users submitted 99 questions to experimental ir systems and received 1086 documents as answers receiving first titles then abstracts and finally full texts ability of users to recognize relevance from shorter formats in comparison to full text judgement was observed of 1086 answers evaluated 843 or 78 had the same judgement on all three formats of 207 answers judged relevant from full text 131 were judged so from titles and 160 from abstracts parallels between users and ir systems performance on shorter formats are drawn
CISI	retrieval of bibliographic entries from a name title catalog by use of truncated search keys an experiment to produce information on the utility of co ordinating derived truncated search keys as enquiry terms to an on line bibliographic system was performed on a file of 132 808 name title entries statistics on the number of entries associated with each key for keys varying from four to eight characters in length were obtained assuming use of a keyboard cathode ray tube terminal capable of displaying at least ten lines of text and taking spelling error probabilities into account a derived key consisting of the first three characters of author name concatenate with the first three characters of title was determined to be effective for at least four fifths of all academic libraries
CISI	retrieval of single entries from a computerized library catalog file the major intellectual challenges confronting an architect of a total computerized library system is organization of a efficient file of millions of bibliographic references from which a single entry can be retrieved swiftly and uniquely research on file organization has concentrated on retrieval of multiple entries possessing some equal or similar characteristic however a basic library bibliographic file should be organized to yield a record unequal and dissimilar to all others such a file is analogous to the familiar main entry catalog which every library maintains and would have associated with it supplementary index files of subjects titles call numbers and perhaps other attributes
CISI	proceedings conference on interlibrary communications and information networks librarians and information scientists are vitally concerned with network development for a number of important reasons first the network concept implies removal of all geographic barriers to knowledge this is made possible by advances in telecommunications technology second a network implies equal access by any individual for any purpose to the sum total of the nations knowledge resources this has been a long standing educational goal and third a network implies positive redirection of the basic professional goals and objectives of librarianship and information science
CISI	a method for the construction of minimum redundancy codes an optimum method of coding an ensemble of messages consisting of a finite number of members is developed a minimum redundancy code is one constructed in such a way that the average number of coding digits per message is minimized
CISI	on the statistics of individual variations of productivity in research laboratories in the following pages a co winner of the 1956 nobel prize in physics presents a novel study of one of todays most precious commodities   scientific productivity the author not only measures the variations that exist between different research workers he also explains these differences and draws some specific conclusions about the relationship of salary to productivity proceedings readers will find this an especially timely ad significant discussion particularly in view of the present widespread concern about manpower shortages and proper utilization of scientific personnel
CISI	communication and epidemic processes it is pointed out that communication processes can be represented as epidemic processes consequently epidemic theory can be applied to the study of any process in which information is transmitted within a population the members of such populations need not be human beings but could be micro organisms or even machines the fundamental notion of stability of an epidemic process is introduced and a stability theorem is derived a mechanism called an information retrieval process which instigates an epidemic process is defined certain general properties of the mechanism are established and the means of controlling it are discussed pontryagins maximum principle is applied to the problem of achieving optimal control of an epidemic process and it is shown that stability of the process is equivalent to stability in the sense of lyapunov this result makes it possible to determine the conditions for stability without knowledge of the solution of the differential equations which represent the process
CISI	pattern classification and scene analysis our purpose in writing this book has been to give a systematic account of major topics in pattern recognition a field concerned with machine recognition of meaningful regularities in noisy or complex environments the most prominent domain independent theory is classification theory the subject of part i of this book based on statistical decision theory it provides formal mathematical procedures for classifying patterns once they have been represented abstractly as vectors attempts to find domain independent procedures for constructing these vector representations have not yielded generally useful results instead every problem area has acquired a collection of procedures suited to its special characteristics of the many areas of interest the pictorial domain has received by far the most attention furthermore work in this area has progressed from picture classification to picture analysis and description part ii of this book is devoted to a systematic presentation of these topics in visual scene analysis
CISI	patterns in the use of books in large research libraries the accumulative growth without limit in ultimate size of the general research library must produce stresses and strains that many institutions will find difficult to resolve the rising costs of space for library buildings and bookstacks the scarcity of centrally located campus land aesthetic and functional limitations on the heights bulk and areas of library buildings and increasing complexity in the organization of materials and services for the efficient use of large research collections are illustrative of some of these stresses and strains
CISI	perceptions an introduction to computational geometry the goal of this study is to reach a deeper understanding of some concepts we believe are crucial to the general theory of computation we will study in great detail a class of computations that make decisions by weighing evidence certainly this problem is of great interest in itself but our real hope is that understanding of its mathematical structure will prepare us eventually to go further into the almost unexplored theory of parallel computers
CISI	personnel administration in libraries since 1958 when the first edition of the present work was issued additional studies research programs and experimentation have contributed to changes in personnel work and the large area of human relations the impact of these developments has been and should be felt in libraries as well as in industry government and business the present edition views all the aspects of personnel work in the context of the most useful of the newer developments
CISI	personnel utilization in libraries a systems approach in the late 1960s nearly all professions in the united states thought they faced severe shortages of manpower in their fields both in professional and supporting areas librarianship was not immune there was more work to be done than existing staffs could do there were budgeted professional vacancies that could not be filled and concurrently there were concerns being quietly expressed that some of the shortages could be ameliorated by a changed utilization of existing manpower it was at this time and out of these concerns that julius r chitwood then president of the illinois library association appointed an ad hoc committee on manpower training and utilization to study patterns of staff assignments and to recommend to library administrators more effective ways of utilizing professional staff after examining the use of professional staff in a few libraries however it became clear to this committee of volunteer researchers that they could not do the job which needed doing it was also clear that a need was there that a small segment of the library manpower problem could be more fully explored that the results of a serious study in illinois might have national implications and that the resources for such a study should be sought
CISI	technical information project the model of a technical information system described there by dr kessler involves a working literature taken from twenty one journals in the field of physics the system designed and constructed at the massachusetts institute of technology as a prototype operating in a realistic test environment uses remote consoles having access to a time sharing computer facility programs have been developed for a large variety of search and processing techniques in real time as well as for delayed output the work is supported by the national science foundation and in part by project mac the experimental computer facility at mit which is sponsored by the advanced research projects agency
CISI	keeping up with whats going on in physics aips current physics information program offers new products to help scientists and engineers stay up to date in 1966 aip had a modest program in physics information supported by the national science foundation the program went back several years and aip was considering a major expansion the first task faced in such an expansion was to augment the staff so as to be interdisciplinary in physics computer operations and scientific information the staff would be able to analyze and extend the studies made at aip and elsewhere and would formulate a basic approach
CISI	is journal publication obsolescent orderly communication through research journals may be jeopardized by a developing national information system that is beginning to encroach on the domain of the primary publication system the author also believes mass distribution of unedited unreferred and often unproofed preprints which has recently been proposed would put journals out of business or transform them into depositories
CISI	is there a pecking order in physics journals analysis of close to a million citations puts physical review at the top of the list but the order changes when we adjust for impact and immediacy when physicists wish to communicate their work by means of publication several considerations are weighed before choosing the appropriate journal there is the matter of audience of the probable delay between acceptance and publication of article format letter review standard research report if the article is potentially controversial the author may estimate its chances of being accepted by different journals considerations of national pride may sway the choice an author may submit a work to a journal in his own country rather than to one that has a greater circulation and impact but is published in a foreign country
CISI	the planning of academic and research library buildings this volume deals with the planning of academic and research library buildings library buildings house library collections of various kinds chiefly books and other printed matter seating accommodations and other facilities for library users quarters for the library staff that acquires catalogues and serves the collections and in addition architectural or what is preferably known as non assignable space if there if space left over after caring for the above needs it is sometimes assigned for other purposes
CISI	planning the college and university library building a book for campus planners and architects this book is intended to help campus planners architects and librarians in the early stages of the planning process three aspects of the problem deserve more careful treatment than they have received these are the effects of automation and electronics on planning the overall organization of service patterns and the relevance of other audiovisual learning media this is a book about the planning process not the details of all parts of a building it will not tell you which floor covering is best which light fixtures to use or which kind of library shelving to buy these matters are treated in detail by metcalf it will however try to tell you how to go about solving these and the many other problems planners face wherever it seems relevant and proper i have included sketches to illustrate the point under discussion for the simplicity of these illustrations i beg the indulgence of the reader
CISI	plans and structure of behavior the notion of a plan that guides behavior is again not entirely accidentally quite similar to the notion of a program that guides an electronic computer in order to discover how to get the image into motion therefore we reviewed once more the cybernetic literature on the analogies between brains and computers between minds and programs our fundamental concern however was to discover whether the cybernetic ideas have any relevance for psychology the men who have pioneered in this area have been remarkably innocent about psychology   the creatures whose behavior they want to simulate often seem more like a mathematicians dream than like living animals but in spite of all the evidence we refused to believe that ignorance of psychology is a cybernetic prerequisite or even an advantage there must be some way to phrase the new ideas so that they can contribute to and profit from the science of behavior that psychologists have created it was the search for that favorable intersection that directed the course of our year long debate
CISI	the practice of management we have available today the knowledge and experience needed for the successful practice of management but there is probably no field of human endeavor where the always tremendous gap between the knowledge and performance of the leaders and the knowledge and performance of the average is wider or more intractable this book does not exclude from its aims the advancement of the frontier of knowledge it hopes indeed to make some contribution to it but its first aim is to narrow the gap between what can be done and what is being done between the leaders in management and the average
CISI	precis a manual of concept analysis and subject indexing in 1951 the british bibliography introduced the relatively new technique of chain indexing to british libraries twenty years later with chain procedure established as one of the standard techniques bnb again pioneered a new approach to subject indexing when it adopted precis from its first issues of 1971 to explain why this change was felt to be necessary we have to consider these indexing systems in the light of the new approaches to handling bibliographic data which have developed over the past decade of so two forces in particular have affected both descriptive cataloguing and subject indexing during this period firstly the introduction of computers secondly and concomitantly the development of bibliographic data exchange networks of which marc is perhaps the primary example in some respects precis represents a parallel development in the field of subject indexing traditionally indexing systems have also tended to be dominated by the concept of a most significant term which once identified by the indexer would be offered as the users access point to the alphabetical file this applied most obviously to subject heading systems a good deal of cutters rules for a dictionary catalog is devoted to the problem of identifying this most significant term in a compound heading and presenting it as the users access point even when this entailed a distortion of natural language and the production of inverted headings the unselected component would then be lost as an entry word unless the indexer also created a further heading or headings in which case none of these headings would be co extensive with the subject of the document
CISI	prejudices and antipathies a tract on the lc subject heads concerning people since the first edition of library of congress subject headings appeared 60 years ago american and other libraries have increasingly relied on this list as the chief authority    if not the sole basis    for subject cataloging there can be no quarrel about the practical necessity for such a labor saving worry reducing work nor  abstractly  about its value as a global standardizing agent a means for achieving some uniformity in an area that would otherwise be chaotic undoubtedly it is a real boon to scholars as well as to ordinary readers to find familiar fairly constant headings in subject catalogs as far removed geographically as washington dc and lusaka zambia knowledge and scholarship are after all universal and a subject scheme should ideally manage to encompass all the facets of what has been printed and subsequently collected in libraries to the satisfaction of the worldwide reading community should that is but in the realm of headings that deal with people and cultures  in short with humanity  the lc list can only satisfy parochial jingoistic europeans and north americans white hued at least nominally christian and preferably protestant in faith comfortably situated in the middle and higher income brackets largely domiciled in suburbia fundamentally loyal to the established order and heavily imbued with the transcendent incomparable glory of western civilization further it reflects a host of untenable  indeed obsolete and arrogant  assumptions with respect to young people and women and exudes something less than sympathy or even fairness toward organized labor and the sexually unorthodox or avant garde
CISI	prestige class and mobility this volume contains the report of a sample survey conducted in denmark 1953 1954 in addition the author has attempted to integrate survey findings with relevant sociological theory and with previous research findings
CISI	principles of numerical taxonomy it is the purpose of this book to present a firm theoretical basis for numerical taxonomy to show why we believe numerical taxonomy has advantages over conventionally practiced taxonomy to report on the previous advances made in the field so far and to furnish newcomers in the field with a detailed step by step description of the procedures employed in numerical taxonomy
CISI	principles of operations research with applications to managerial decisions this book is written primarily for college students who have no previous background in operations research and who intend careers as administrators consultants executives or managers in business nonprofit enterprises or government the broad topic coverage also should make the text helpful for students who seek careers as teachers and researchers as well as for practitioners who desire an up to date review of operations research the book can be used in half year or full year introductory courses for juniors seniors or graduates in business economics and engineering curricula the central goal of the book is to answer the question what are the fundamental ideas of operations research the text does not presuppose any advanced training in business administration industrial engineering mathematics statistics probability theory or economics therefore the main ideas do not rely on the readers being expert in these areas the text does assume however that the reader is not entirely naive about such subjects
CISI	nature of information the book considers connections between the concept of information and some philosophical categories reveals the possibility of applying theoretical  informational methods in logic gnosiology epistemology or theory of knowledge
CISI	problems in organizing library collections in the area of library work often called cataloging and more broadly technical services the student may fall into two errors that of assuming that all work is strictly routine and mechanical and that of viewing the tasks of organizing a library collection as self contained one purpose of the case studies here presented is to help correct both these errors and to do so by illuminating some of the ways in which interpersonal relations affect the character of the routines and by setting the organizational tasks in the broader context of the total library situation
CISI	russian descriptor informatics dictionary this dictionary contains general alphabetical list of descriptors and synonymous keywords and word combinations it is intended for use in coordinating the indexing of documents
CISI	problems of information service a major prospect for meeting the present critical situation in the domain of scientific communications   which is a natural corollary of the advancement of scientific and technical revolution is the development and practical implementation of a special type of information systems known as integrated information systems
CISI	on one model of semantic information theory text processing problems such as automatic translation and automatic abstracting create a need for defining explicit concepts which should be characterized as the properties and quantity of semantic information contained in document texts in fact we need a formal model which lets us describe the process of semantic text analysis semantic text analysis could be described from the point of view of someone with a different conception of the world   e g the text of very meaningful article does not contain in fact any information for people who are not specialists in the given mathematic field therefore the formal model must contain descriptions of the conception of the world of the given observer such a description we call a thesaurus semantic text analysis we interpret as changing the thesaurus in response to a given text
CISI	on semantic synthesis this paper describes a system for the automatic synthesis of a text in a natural language russian the primary characteristic of this system is its semantic nature and the plurality of its synthesis
CISI	evaluation of methods of formal investigation of texts in dead languages an account is given of the principles for automatic decipherment of historical documents which are used by te viniti group under the leadership of m a probst the author considers problems of dividing texts into blocks classification of morphemes into auxiliary and root morphemes by means of the variational principle and establishment of correspondences between related languages
CISI	production and distribution anything that goes under the name of production and distribution sounds as if it clearly fell into the economists domain an analysis of knowledge on the other hand seems to be the philosophers task though some aspects of it are claimed by the sociologist but if one speaks of the communication of knowledge in the united states the specialist in education may feel that this is in his bailiwick also the mathematician or operations researcher specializing in communication theory and information systems may prick up his ears in fact some of the knowledge to be discussed here is technological and thus the engineer may properly be interested when i tried out the title of this study on representatives of various disciplines many were rather surprised that an economist would find himself qualified to undertake this kind of research
CISI	the prognostication of science science is developing at a rapid pace the modern scientific and technical revolution has as its outcome an unprecedented fact the transformation of science in an ever growing manner and along the growing front of scientific disciplines into an immediately productive and social force of society
CISI	the application of microform to manual and machine readable catalogues at birmingham university library it is proposed to implement in october l972 a complete microfilm catalogue system this system originated from two sources over the past two years various means have been evaluated of converting the librarys card catalogues which were closed at the end of 1971 to a more compact form an interim report mentioned microfilming as one of a number of possibilities at the time the production of hard copy was envisaged but since then a true microform system has seemed preferable in which the catalogue would exist as cassettes of film to be viewed by all users on reader machines this system has been specified and costed and details are included in this paper the impetus in reaching this viewpoint was provided by the progress made over the last 18 months in the field of com which rapidly commended itself as the choice of output medium for the new mechanized marc based catalogue which covers all the librarys serials and all monographs acquired after january 1972 blcmp union catalogues in these categories will also be held in com form at birmingham university library
CISI	book selection from marc tapes a feasibility study the technical and economic feasibility of providing selective notifications of current books to specialized libraries by extraction from marc tapes has been explored an experimental on line system marcas was used to test profile construction and the utility of the various elements in marc records as search keys the programs allowed both weighted and boolean searching on the title and author lc classification and subject headings and the bnb precis indexing terms and reference index numbers test profiles were constructed for nine libraries covering a range of subject fields and run on six weeks of bnb and six weeks of lc marc tapes the output was assessed for relevance and recall and the results analyzed in terms of precision and recall for various combinations of searchable fields the best performance with recall and precision both about 50 was given by searching all verbal fields together   title and author lc subject headings and bnb tapes only precis indexing terms costs for the experimental on line system and a batch version of the system are identified
CISI	prolegomena to library classification even while edition 2 was under preparation seeds had been sown to take the study of the theory of classification to a deeper level with the co operation of a wider circle of workers an international conference of libraries and documentation centres was held in brussels from 11 to 18 september 1955 during the conference a whole forenoon was devoted to a group meeting on classification general and special under my chairmanship the following two resolutions recommended by the group meeting were adopted by the plenary meeting on 16 september 1955 1 the fid recommends that a deeper and more extensive study should be made of the general theory of classification including facet analysis and also of their application in the documentation of specific subjects 2 the commission proposes that in liaison with the fid ca committee a permanent working group be created in order to make mutual exchange of theoreticians experiences and points of view possible the rapporteurs shall bring about the creation of such a group and furnish the information and means of work in order that practical results may be obtained in the shortest time by making mail exchanges easier and more frequent the scheme proposed by dr ranganathan will serve as the basic document 154 further at its meeting held on 16 september 1955 the council of fid requested its bureau to convene an international seminar on classification this was in accord with the memorandum prepared by me at the request of donker duyvis 133
CISI	the magical number seven plus or minus two some limits on our capacity for processing information my problem is that i have been persecuted by an integer for seven years this number has followed me around has intruded in my most private data and has assaulted me from the pages of our most public journals this number assumes a variety of disguises being sometimes a little larger and sometimes a little smaller than usual but never changing so much as to be unrecognizable the persistence with which this number plagues me is far more than a random accident there is to quote a famous senator a design behind it some pattern governing its appearances either there really is something unusual about the number or else i am suffering from delusions of persecution
CISI	a theory of human motivation the present paper is an attempt to formulate a positive theory of motivation which will satisfy these theoretical demands and at the same time conform to the known facts clinical and observational as well as experimental it derives most directly however from clinical experience this theory is i think in the functionalist tradition of james and dewey and is fused with the holism of wertheimer goldstein and gestalt psychology and with the dynamicism of freud and adler this fusion of synthesis may arbitrarily be called a general dynamic theory
CISI	multidimensional scaling by optimizing goodness of fit to a nonmetric hypothesis multidimensional scaling is the problem of representing n objects geometrically by n points so that the interpoint distances correspond in some sense to experimental dissimilarities between objects in just what sense distances and dissimilarities should correspond has been left rather vague in most approaches thus leaving these approaches logically incomplete our fundamental hypothesis is that dissimilarities and distances are monotonically related we define a quantitative intuitively satisfying measure of goodness of fit to this hypothesis our technique of multidimensional scaling is to compute that configuration of points which optimizes the goodness of fit a practical computer program for doing the calculations is described in a companion paper
CISI	public knowledge an essay concerning the social dimension of science natural science whose internal development for three centuries is so uniform well documented and relatively self  generating is an obvious candidate for such treatment and having noticed the intellectual connections between the ideas of various scholars we must surely pass on to an investigation of the social relations through which those connections are established how do scientists teach communicate with promote criticize honour give ear to give patronage to one another what is the nature of the community to which they adhere
CISI	public libraries in cooperative systems administrative patterns for service this book was written as an introduction to the administrative relationships between small and medium sized public libraries and the cooperative library system in this book the definition of a cooperative system is as follows a cooperative library system is the combining of the talents and the resources of a group of independent libraries within a reasonable geographic radius for the purpose of attaining excellence in service and resources for the benefit of the actual and potential users of all the member libraries the plan for the book originated with questions directed to a public library administrator and to a system director the most pertinent of the repeated questions was how does system membership change local library administration the sharpest question was will the system ultimately take over local rights and responsibilities
CISI	public libraries as culture and social centers the origin of the concept this book is an attempt to trace the origins of non  book activities in public libraries by which is meant the arrangement of fiestas festivals and exhibitions the conduct of classes contests lectures and excursions the staging of plays the exhibition of movies the demonstration of karate and judo and all similar activities not primarily concerned with books now carried on by public libraries since ideas about libraries as well as librarians have passed back and forth across the atlantic with great facility in this attempt to discover origins it seems wise to follow however sketchily developments in both america and britain and to note with some care what was happening in scholarly libraries in popular libraries for the middle classes and in libraries intended for the working classes
CISI	public library and city this volume is an edited collection of some papers from the 1963 symposium on library functions in the changing metropolis sponsored by the joint center for urban studies and the national book committee not all the papers delivered at the symposium are included and papers by banfield blasingame and myself were written especially for this volume the authors are urban social scientists economists historians sociologists political scientists planners communication experts library scholars and library administrators the papers are about libraries and cities and their main purpose is to raise issues about the character of cities and the future of libraries whose milieu is the city
CISI	public library legislation since its inception unesco has engaged in activities designed to promote the expansion and improvement of public library services as a living force for popular education and international understanding these activities have included public library pilot projects   colombo ceylon medellin colombia delhi india abidjan ivory coast enugu nigeria   training of librarians and meetings of experts on planning library services it has become increasingly evident that effective public library services cannot be developed and maintained without appropriate legislation providing for a nation wide service offering as far as possible equal contract with the international federation of library associations ifla for a comparative study of existing library legislation that would be helpful to developing and developed countries alike in drafting legislation
CISI	the public library in the united states the study as a whole is designed to stimulate public librarians to re examine realistically their most useful function and greatest potential contribution at a time when methods of communication are undergoing rapid change as the traditional custodian of the printed word the librarian has long had a distinctive and widely accepted role the public library inquiry especially in the concluding chapter of the present volume brings to the center of attention problems and suggestions for change challenging a fresh appraisal it should arouse the interest of the public served by the libraries as well as aid the librarians themselves to an appreciation of an important american institution that must be kept ever alert to the needs of a democratic society
CISI	publishers and libraries the purpose of this study is to report on the viability of the journals system for communicating scholarly and research information overall it examines the economics of the interaction between the publisher and library components in this system and seeks to identify the separate and interdependent problems of each data have been collected for the five year period 1969 73 as a basis for analysis and interpretation emerging issues and trends are identified and evaluated for their possible future impact when supported by data and information derived from the study conclusions and recommendations are offered aimed at possible solutions or processes for stabilizing the present deteriorating situation and the consequent drift toward a general crisis in journal communication
CISI	quantitative methods this institute was designed both to encourage the use of quantitative measurement and to teach the techniques necessary for such use it was hoped that an emphasis on statistical measurement would upgrade administrative and research skills and thus contribute to more efficient and effective library management studies of librarians academic backgrounds have indicated a preponderance of humanities and social science majors in the field too often librarians have had only a few courses in mathematics and some actually have a psychological antipathy toward numbers this anti mathematics syndrome has kept librarians from taking proper advantage of quantitative methods
CISI	rare book librarianship although there is an extensive and enjoyable literature on the subject of rare books most of it is concerned with bibliography or book collecting and relatively little on the librarianship of rare books is available this book is an attempt to consider some of the problems of custodianship and exploitation of special collections in libraries problems sufficiently different i believe to make the concept of rare book librarianship a valid one it is based distantly upon lecture notes for a course on this subject which was offered to postgraduate students at loughborough university
CISI	rate distortion theory a mathematical basis for data compression the branch of information theory devoted to situations in which the entropy of the source exceeds the capacity of the channel is called rate distortion theory the name derives from c e shannons concept of the rate distortion function of an information source with respect to a fidelity criterion which serves as the cornerstone of the theory rate distortion theory provides a mathematical basis for the rapidly evolving branch of communication engineering commonly referred to as data compression bandwidth compression or redundancy reduction
CISI	reader in documents of international organizations the purpose of this volume is to give an insight into the nature and scope of the documents of international organizations and to provide information about the work of documentalists and librarians in making the mass of information available in these documents available to readers all too many librarians regard government documents and in particular the documents of international agencies as esoteric unlike the usual library materials in format and publication pattern and as presenting problems of acquisitions control and service so complex and so frustrating that they are best left to the specialist in documents the result is that international documents are a puzzlement to the general librarian and a source of frustration to the ill informed administrator a situation exacerbated by the present general tendency of library school curricula to ignore the question of international documents except for cursory mention in one or at most two sessions of a general course in government documents to which relatively few students are exposed the information in this volume will allay the fears of the generalist librarian it also provides the data on which to base additional emphasis on international documents in the library school curriculum
CISI	reader instruction in colleges and universities definition what is reader instruction another currently used term is library instruction which puts the emphasis on the library rather than the reader and which also suggests to some that library instruction concerns the training of librarians for the purpose of this introductory handbook reader instruction is taken to mean instruction given to readers to help them make the best use of a library particularly an academic library of some size and complexity
CISI	reader in library cooperation this volume is intended as a means of exploration for the practicing librarian and as a textbook for the library school student it will try to draw attention to significant social behavioral theoretical organizational functional and operational generalizations about library interrelationships and to suggest a sense of the total fabric of the cooperative endeavor it does not aim at identifying and incorporating the forms and the range of library cooperation in which individual libraries seek to extend the limits of their separate capabilities
CISI	reader in library service and the computer the selections are intended mainly for students in library schools and for librarians in the field who have not yet made themselves conversant with the literature of computer based operations this is not a book to state the proposition in the negative for those who wish to read on the theoretical aspects of computers the selections are brought together in seven sections the first the challenge includes material on what is expected of librarians in the age of the computer the second section varieties of response does not by any means exhaust developments in american libraries it does i believe contain representative descriptions of some of the best work being accomplished the third section theory of management contains an outstanding article by richard degennaro of harvard the particular contributions made in this article are described in the editorial comment immediately preceding this third section news services the fourth section required a considerable degree of selection among a wealth of material and is indicative of the wide variety of services which libraries are beginning to offer in the age of the computer the considerable range of such services is exhaustively indicated in the first selection of this section while those that follow describe specific services now being offered or services in the planning stage the material in the fifth section catalogs and the computer is on a subject that has elicited considerable discussion the two articles selected are on two aspects of the subject namely filing problems and comparative costs the sixth section copyright contains an article from the legal point of view the more traditional library view of copyright has been ably represented by verner clapp in an article cited in the section on additional readings the seventh section information retrieval testing is a subject which has excited the attention of but few librarians yet its influence on subject indexing could in time prove considerable
CISI	reader in medical librarianship each kind of librarianship partakes of the general elements of librarianship and each has a flavor all its own this book is intended to present the flavor and philosophy of medical librarianship to the student or novice if it gives a new perspective to some practicing librarians or administrators in health science organizations so much the better if it were ever possible to think of medical libraries in isolation it is so no longer one must conceive of them as part of a medical system and indeed as part of a system that goes beyond the narrow confines of medicine as practiced by a single physician for a single patient it extends into the health sciences as represented by dentists pharmacists nurses veterinarians medical technologists medical associates and dozens of others some not yet possessing a clear identity it includes research education and practice in addition to the clinical sciences the system involves the preclinical ones and preventive medicine and public health increasingly socioeconomic considerations have moved into the mainstream of medicine
CISI	reader in research methods for librarianship the fundamental purpose of this volume is to assist its reader to genuinely perceive the nature of scholarship and its relationship to the goals of librarianship viewed in this way and perhaps as antidote to the more rigidly formalistic treatments of the technical matters of research the editors concern here has been less with the rituals and far more with the fundamental nature of intellectual inquiry and its societal contribution with the modes of analysis the habits of thought and expression which characterize scholarship and the scholar another primary purpose has been to put research into a context which clearly depicts the task of the researcher and so illuminates realistically not only the rigor and the discipline but the human triumphs and joys which derive from its accomplishment seen thus as a dynamic field fit for the adventurer of the mind perhaps it may succeed in enticing more to its fold from among those in librarianship with imaginative and creative capacity who have not before held this perspective of research
CISI	reader in technical services this collection attempts to bring together a readable and germane group of materials ranging from history review papers and practical exposition to reports on current research and development and conjecture about the future it is expected that these selections will be of interest and use to the teacher and student it is also hoped that they will be of equal interest to the professional librarian and researcher there has been a deliberate attempt to exclude materials that have appeared in recently published collections it is for this reason that the names of panizzi cutter martel hanson dewey rider bliss haykin shera lubetzky and others do not appear a specific focus has been given to this book it is in the direction of a rational sharing of local national and international efforts and the eventual coordination and standardization of practices in the technical services insofar as this is practical
CISI	the recording of library of congress bibliographical data in machine form this report describes the results of a study of a practical method of preparing library of congress card catalog data in machine form for 1 the automatic typesetting of cards and book catalogs and 2 distribution to other libraries throughout the country for all foreseeable bibliographic and typographic applications of such data including preparation of local catalogs the first step of the method proposed is to type the card data on a perforated tape typewriter in a way which identifies all of the items on the card after the data is edited and corrected it is processed by a computer to form 1 catalog card typesetting tapes 2 the national union catalog 3 library of congress books subjects catalog magnetic tape catalog files and a master magnetic or perforated paper tape record copy for distribution the procedure also allows the recording of data which does not now appear on library of congress cards should studies find that the value of the data exceeds the cost of recording it a demonstration was performed in which cards were typed to produce perforated tape records these record tapes were automatically converted to a variety of output forms ranging from phototypeset catalog cards and book catalog entries to tape typewriter and line printer produced catalog cards
CISI	relegation and stock control in libraries stock control has been defined by buckland as the managerial problem of organising the physical availability of books in relation to readers while it has long been recognised that only a proportion of the stock of academic libraries is actively used academic library buildings grow both more expensive and approach capacity fullness with remarkable speed in certain cases some new buildings are full even before they have left the design board stage it is difficult to avoid the conclusion reached by r b morris in 1963 that in terms of long range perspective responsible judgement suggests that there is no feasible choice before libraries other than a wide and continuous programme of selective book retirement  library stock control has not received the attention it merits from librarians whose energy time and resources have been more than fully committed by the problems of acquisition and the provision of an ever increasing range of services for readers early investigations of this issue have tended to be theoretical and carol seymour in her review weeding the collection put forward the view that a librarian should be able to begin his plan for weeding even if the day seems far off when weeding will be necessary he also knows the sorts of information tools he will need to have at hand when the day does dawn on his overgrown garden the pebul report summarised the position in a remarkably appropriate metaphor when it observed that weeding the bookstock in academic libraries was the ungrasped nettle
CISI	report of an investigation on literature searching by research scientists this is a factual report of the investigation it includes all the numerical results which were judged to be worth reporting the whole of the data collected for the investigation is available on punched cards and further analyzes can be made from these if required by members of aslib the broad significance of the results and any conclusions to be drawn from them are discussed in papers now being prepared for publication elsewhere in this report only such discussion is included as is necessary to clarify the data presented
CISI	report on the testing and analysis of an investigation into the comparative efficiency of indexing systems this volume continues the account of the aslib cranfield project as given in the final report of the first stage of an investigation into the comparative efficiency of indexing systems the major portion of the two years spent on this present stage has been involved with the analysis of the considerable amount of data which was obtained from the main test programme a difficulty in this work was in deciding on the type of analysis which would be most likely to yield valuable information in order to keep this volume within reasonable limits it has been necessary to select from the analysis that was done and even so in many cases only brief examples are given the major emphasis has been placed on the reasons for failure to retrieve source documents for this is considered to give some of the most interesting results of the project and has not to our knowledge been previously attempted of possible equal importance but certainly more difficult to evaluate is the reason for the retrieval of non relevant references this analysis has not been attempted within the present work but will be one of the matters to be investigated in the continuation of the project
CISI	the growth of the literature of physics an examination is made of the current problems of the communication and dissemination of literature in the field of physics the growth of the literature is considered quantitatively with respect to the form subject and origin of published material this is related to the general growth in scientific activity as exemplified by increases in numbers of physicists and of expenditure on research the results of surveys aimed at ascertaining the needs or demands of users of the physics literature are considered particularly where these reveal weakness in the present organization of information transfer and the reactions of users to new services intended to remedy the deficiencies finally a number of recently established services   some designed to meet hitherto unsatisfied needs   are described the role of the computer in the development of local national and international documentation systems is examined
CISI	research libraries and technology the focus of the report is primarily upon the problems of the large university research oriented library it is here that one finds the most difficult resource access and bibliographical control problems if one can significantly improve both of these operations for the large research oriented institutions there are likely to be direct or indirect benefits for the smaller library while the reverse situation is much less likely
CISI	resources and bibliographic support for a nationwide library program final report to the national commission for libraries and information science foremost among the nationwide goals of the library community is the access to needed information resources for all persons in all locations in the u s the perceived right of individuals to such access provides the foundation for national information planning for each library even the largest the hope of adequately supplying its identified user groups has been greatly constrained by simultaneous inflation of both cost and quantity of materials while future technological developments may well make possible on line full text retrieval of all library materials at local terminals or the instantaneous remote publication of materials upon demand the present situation requires more immediate solutions
CISI	categories and relators a new scheme if the major premise is accepted that fully effective machine strategization of a retrieval system depends upon the use of a hierarchically structural but highly flexible notation as the equivalent for the verbal access provided by either unitermic or articulated conceptual indicators a faceted classification logically emerges as the desideratum the two aspects of a structural notation most determinative here are hierarchicality and uniform use of general categories the latter not merely for the sake of uniformity as such but as the means to a heightened flexibility these desiderata could of course be present on the idea plane alone but without their being present notationally they do not furnish to a mechanized retrieval system the type of assistance it requires for optimal functioning the second minor premise ought to be that the universal decimal classification being both hierarchical and general categoric provides the desired structurality but the melancholy fact is that this desideratum is not always satisfied for instance when udc uses direct division of a hierarchy when division by general category would be equally appropriate
CISI	the review of scientific instruments with physics news and views a study of the periodicals for the subjects of physics and radio has been undertaken with the hope of indicating those which are most used in each field the method selected is similar to that used by p l k gross and e m gross
CISI	the ring index the collection includes 1 simple parent rings and 2 parent systems of more than one ring in which the rings are united by having one or more atoms in common it thus comparizes simple and fused ortho  and ortho peri fused or annelated systems including spiro forms but not systems like biphenyl or triphenylmethane in which the rings are united only by valences or by atoms not belonging to the rings some systems are included in which a polar valence is involved e g the four membered ring of betaine since these are often shown in formulas as if true rings but in such cases the presence of the polar bond is noted polar bonds in metallic salts e g calcium succinate are disregarded as ring formers so also are coordinate linkages as in the chelate compounds the word system is used to mean a single ring or a combination of rings united one to another by atoms common to both except for some special reason only systems representing known compounds of generally accepted structure or definitely believed by authors to have a certain structure are included the fact that a compound must have one or two alternative structures is not sufficient for the entry of a system based on either of them where there is doubt about an entry a query is inserted after the reference
CISI	the rise of anthropological theory my main reason for writing this book is to reassert the methodological priority of the search for the laws of history in the science of man there is an urgency associated with this rededication which grows in direct proportion to the increase in the funding and planning of anthropological research and especially to the role anthropologists have been asked to assume in the planning and carrying out of international development programs a general theory of history is required if the expansion of disposable research funds is to result in something other than the rapid growth in the amount of trivia being published in the learned journals the publishing of more and more about less and less is an acceptable consequence of affluence only if specialization does not lead to an actual neglect or even obfuscation of fundamental issues
CISI	why dont they ask questions recently a great deal of emphasis has been placed upon communications interviewing and advisory counseling in the field of library science studies done in these areas have dealt mainly with communication barriers verbal and nonverbal communication question negotiation and patterns of information seeking interviewing techniques for librarians customer relations and reference performance as they relate to the user and his confrontation with a librarian in seeking an answer to his question however it seems that few people have been concerned with the user who for one reason or another does not ask a librarian for assistance
CISI	cost of computer searching the program which i will discuss has the primary objective of making new technology and research information generated in federally supported research programs available for use by industry and government for both private and public benefits our group had no part in creating the information resources which we use except for the design of the computer retrieval system although we work with and depend on conventional libraries and librarians we have no professional librarians on our staff
CISI	rules for a dictionary catalog no code of cataloging could be adopted in all points by every one because the libraries for study and the libraries for reading have different objects and those which combine the two do so in different proportions again the preparation of a catalog must vary as it is to be manuscript or printed and if the latter as it is to be merely an index to the library giving in the shortest possible compass clues by which the public can find books or is to attempt to furnish more information on various points or finally is to be made with a certain regard to what may be called style without pretending to exactness we may divide dictionary catalogs into short title medium title and full title or bibliographic typical examples of the three being 1 the boston mercantile 1869 or the cincinnati public 1871 2 the boston public 1861 and 1866 the boston athenaeum 1874 82 3 the catalog now making by the library of congress to avoid the constant repetition of such phrases as the full catalog of a large library and a concise finding list i shall use the three words short medium and full as proper names with the preliminary caution that the short family are not all the same size that there is more than one medium and that full may be fuller and fullest short if single columned is generally a title a liner if printed in double columns it allows the title occasionally to exceed one line but not if possible two medium does not limit itself in this way but it seldom exceeds four lines and gets many titles into a single line full usually fills three or four lines and often takes six or seven for a title
CISI	rules for a dictionary catalog no code of cataloguing could be adopted in all points by everyone because the libraries for study and the libraries for reading have different objects and those which combine the two do so in different proportions again the preparation of a catalogue must vary as it is to be manuscript or printed and if the latter as it is to be merely an index to the library giving in the shortest possible compass clues by which the public can find books or is to attempt to furnish more information on various points or finally is to be made with a certain regard to what may be called style
CISI	russian declension this book describes exhaustive classification of the declensional types noun adjective participle mineral pronoun in modern russian literary language and rules of formation for all word forms of any declinable russian word the description of the russian declensional system which given in present monography has great importance on the one hand for such practical problems as the teaching russian and the development of automatic russian text synthesis and on the another hand for a general theory of declension and for the typological study of slavic languages
CISI	the scholar and the future of the research library of all the problems which have of recent years engaged the attention of educators and librarians none have been more puzzling than those posed by the astonishing growth of our great research libraries my own interest in this subject has over several years resulted in a series of papers some of them mainly analyzes but others of them endeavoring to suggest answers to what has sometimes seemed to be an almost insoluble puzzle
CISI	scholarly reprint publishing in the united states with this book i try to offer readers a broad picture of the current reprint industry as well as an account detailed enough to capture the fast moving reprint scene from various viewpoints
CISI	science since babylon this book had its origin in a set of five public lectures given at the sterling memorial library at yale university during october and november 1959 under the auspices of the yale department of history the subject whatever its name had just come through a stage in its growing up during which it almost seemed as though every would be practitioner of the art deemed it necessary to exhibit the completeness of his dedication by writing the history of the whole of science through all its periods hoping that this historiographic phase had evaporated and feeling incompetent in too many scientific and historical directions i resolved instead to essay the experiment of speaking only from those areas in which i had reasonable firsthand experience at research
CISI	is a scientific revolution taking place in psychology my plan in this paper is to try to apply to the field of experimental psychology the analysis of the characteristics of science and more particularly the structure of scientific revolutions as conceptualized by t s kuhn kuhn has not been accepted without criticism but that need not prevent us from using his book as a point of departure for discussion i assume that the reader will be familiar with kuhns analysis so that only a sketchy summary of his position is necessary i will then take a brief look at some of the history of psychology with special emphasis upon the major tenets of behaviorism finally i will advance some evidence to suggest that we may well be living in an era of revolution within psychology as well as without
CISI	is a kuhnian analysis applicable to psychology as my title might suggest i wish to discuss some aspects of palermos recent paper the thesis which palermo advocated is that kuhns view of scientific revolution is applicable to the recent history of experimental psychology and that in particular experimental psychology has had two paradigms already with the appropriate scientific revolution between them and that the current behavioristic paradigm may well be in a state of kuhnian crisis the present note is divided into three parts the first questions palermos assertion that the transition from introspectionism to behaviorism was a standard kuhnian paradigm change the second closely tied to the first challenges the assumption that behaviorism itself can really be seen as a kuhnian paradigm finally the third supports palermos thesis that behaviorism is in a crisis state but advances an alternative account of the reasons for this
CISI	bibliographical statistics as a guide to growth points in science efforts have been made in recent years to use statistical studies of scientific research papers as a means for deriving general statements about trends in science for example there has been a continuing interest in the question of how the frequency of citation of a scientific paper depends on its age these investigations have however been mainly concerned with the major branches of science only and have also perhaps been rather more interested in identifying past trends than in making specific predictions for the future although such results are obviously valuable it is also important to push these analyses further into smaller areas within a main scientific subject division since such areas may have significantly different bibliographical properties from the subject average one particularly important aspect of such work concerns the origin of new growth areas within a major discipline we can specifically pose the question is it possible purely from a statistical analysis of scientific research papers to identify the appearance of a new growth area and if so how soon after its first appearance can such an area be identified
CISI	the structure of scientific literatures ii toward a macro  and microstructure for science part i of this paper described the first steps in mapping the scientific literature using a new technique   co citation   to measure the degree of similarity among documents the work developed directly from an earlier paper which defined this measure and explored its relationship to other citation measures for identifying relationships among documents we now report the outcome of an attempt to create maps of the scientific literature the scales of these maps have been systematically manipulated so that they present not only an overview of all highly cited papers in natural science but also a detailed view of a single scientific specialty at each level we have systematically sought indications of the validity of the mapping operation and have indications that the maps display at least certain important aspects of the specialty structure of science
CISI	college libraries and chemical education the small college has stood staunch in its desire to supply the liberal education and perhaps it has done well in maintaining this position on the other hand many of the large universities have shifted the emphasis from undergraduate work to graduate study still others have tried to develop both side by side few of the small colleges have kept astride with the inevitable consequences of such a situation the few who have are sending an increasing number of their graduates to these universities to complete their training as an example of this it is the boast of pomona college that over seventy per cent of her graduates have taken subsequent professional training it has become the evident duty therefore of the small college to prepare its men not only to enter such graduate schools but also to meet successfully the ever increasing intensity of competition found there this in addition to supplying a broad cultural education this duty has brought with it a number of problems of first magnitude one of the biggest of these is the problem of adequate library facilities it is the purpose of this paper to discuss this problem with special reference to the student whose college major is chemistry
CISI	serial literature used by american geologists the present investigation deals with the serial literature of geology including mineralogy six american journals for 1929 were chosen and the references tabulated in table i are listed these source journals together with the total number of pages of the actual articles studied the total number of citations in each journal the number of references to books and to personal communications and the net total which represents the citations to serial literature it is these last mentioned references which will be considered in further detail the totals are probably slightly high due to unintentional counting in single articles of repetitions of the same citation
CISI	citation indexes for science in this paper i propose a bibliographic system for science literature that can eliminate the uncritical citation of fraudulent incomplete or obsolete data by making it possible for the conscientious scholar to be aware of criticisms of earlier papers it is too much to expect a research worker to spend an inordinate amount of time searching for the bibliographic descendants of antecedent papers it would not be excessive to demand that the thorough scholar check all papers that have cited or criticized such papers if they could be located quickly the citation index makes this check practicable even if there were no other use for a citation index than that of minimizing the citation of poor data the index would be well worth the effort required to compile it this paper considers the possible utility of a citation index that offers a new approach to subject control of the literature of science by virtue of its different construction it tends to bring together material that would never be collated by the usual subject indexing it is best described as an association of ideas index and it gives the reader as much leeway as he requires suggestiveness through association of ideas is offered by conventional subject indexes but only within the limits of a particular subject heading
CISI	mathematical evaluation of the scientific serial in this article is offered an improved citation count method designed to measure qualitatively the value of any scientific serial by means of a related quantitative citation count
CISI	identifying significant research literature citation counting is evaluated as a means for identification of significant research
CISI	searching natural language text by computer machine indexing and text searching offer an approach to the basic problems of library automation
CISI	relative effectiveness of document titles and abstracts for determining relevance of documents abstract individuals who received documents through a selective dissemination of information system were asked to determine the relevance of documents to their work interests on the basis of titles and of abstracts the results indicate that there was no significant difference between the usefulness of titles and of abstracts for this purpose
CISI	information retrieval systems statistical decision theory may provide a measure of effectiveness better than measures proposed to date
CISI	science citation index   a new dimension in indexing this unique approach underlies versatile bibliographic systems for communicating and evaluating information
CISI	scientific information exchange in psychology the immediate dissemination of research findings is described for one science the immediate dissemination of research findings is described for one science
CISI	networks of scientific papers this article is an attempt to describe in the broadest outline the nature of the total world network of scientific papers we shall try to picture the network which is obtained by linking each published paper to the other papers directly associated with it
CISI	quantitative growth of the mathematical literature since 1868 the number of mathematical publications per year measured by counts of titles abstracted has grown from about 800 to 13 000 at an average continuous compound rate of about 2 5 percent per year doubling about four times a century deviations from the exponential curve are clearly related to war depression and recovery if the total number of publications prior to 1868 is estimated by extrapolating from the curve of annual output the cumulative grand total of mathematical titles grows from 41 000 in 1867 to 419 000 by the end of 1965 deviations from an exponential growth of 2 5 percent per year are negligible except for two pauses during world wars after which the observations continue parallel to the theoretical curve the well known hypothesis of exponential growth of the scientific literature is strongly confirmed but at a rate less than half that found by price and other investigators the discrepancy appears to be due to the failure of previous studies to take into account the titles published before the beginnings of the time series used
CISI	citation indexing and evaluation of scientific papers the spread of influence in populations of scientific papers may become a subject for quantitative analysis
CISI	project hindsight defense department study of the utility of research
CISI	scientific communication as a social system the exchange of information on research evolves predictably and can be experimentally modified
CISI	the future of scientific journals a computer based system will enable a subscriber to receive a personalized stream of papers
CISI	the matthew effect in science this paper develops a conception of ways in which certain psychosocial processes affect the allocation of rewards to scientists for their contributions   an allocation which in turn affects the flow of ideas and findings through the communication networks of science the conception is based upon an analysis of the composite of experience reported in harriet zuckermans interviews with nobel laureates in the united states 1 and upon data drawn from the diaries letters notebooks scientific papers and biographies of other scientists
CISI	computer assisted design of complex organic synthesis this article is concerned with the general theory of chemical synthesis and with the application of machine computation to the generation of chemical pathways for the synthesis of complicated organic molecules the basis for the approach which has been developed comes in large measure from the methods used by chemists in the solution of certain types of synthetic problems
CISI	psychology apprehension over a new communications system dissension has arisen in the american psychological association apa over a multimillion dollar plan to establish a national information system for psychology the plan would supplement the existing psychology journals with a computerized system for distributing unedited manuscripts on a rapid fire basis
CISI	automatic text analysis in this article the principal experiments in automatic text analysis are briefly reviewed and an indication is given of developments to be expected in the future
CISI	communication or chaos effective transfer of scientific and technical information continues to be a pressing national problem
CISI	computer based chemical information services some new aids for the research scientist are described
CISI	communication in the physical and social sciences this article focuses on differences between the physical and the social sciences regarding three major factors associated with the dissemination and assimilation of scientific information i lags in the process of information flow ii the organization and effectiveness of informal networks and iii the transfer of information from the informal to the formal domain
CISI	selective dissemination and indexing of scientific information automated methods for selective dissemination of information sdi to individual scientists and engineers play an important role in dealing with the increasing avalanche of scientific information this article presents some basic aspects of sdi systems and describes recent developments and problems two different approaches to indexing information for sdi systems are discussed with emphasis on the desirability of using enumerative hierarchical classifications to improve the precision and quality of matching scientists with useful documents
CISI	current physics information a new concept in science communication will be given its first test in calendar year 1972 primary and secondary contents of a selected subset of the worlds journal literature in physics will be provided in a variety of output formats among them are a monthly microfilm containing the full texts of all articles in the set of journals current physics microform an advance abstracts journal describing the articles current physics advance abstracts a printed classified index of the titles of the articles current physics titles and a computer tape index to the articles searchable physics information notices
CISI	coherent social groups in scientific change this article examines findings from surveys individual interviews and bibliographical essays and discusses the similarities among contemporary groups that developed into small coherent activist groups and that subsequently had major impacts on their home disciplines
CISI	citation analysis as a tool in journal evaluation journals can be ranked by frequency and impact of citations for science policy studies
CISI	the ortega hypothesis citation analysis suggests that only a few scientists contribute to scientific progress
CISI	on line services in medicine and beyond a national and international bibliographic information network for science and technology is now evolving
CISI	citation analysis the science citation index is a valuable and powerful tool when used for the purpose for which it was intended as an aid in literature search it also invites a variety of statistical investigations which must however be considered with prudence since they may lead to misleading results no matter how cautiously the authors express themselves the casual readers that is the majority will treat the results as established facts and forget about the assumptions underlying them this is also happening with the computer output for economic models which is accepted as if it were experimental observation
CISI	copyright public policy and information technology it is my purpose to single out two major information technologies that have already fostered considerable controversies   computer based information storage and retrieval systems and photocopying technologies   and analyze the costs and benefits they have produced in various knowledge  sensitive circles of american society i also suggest some immediate policy steps that might be taken concerning computers photocopiers and other information technologies
CISI	copyright its adequacy in technological societies the traditional copyright concept may not be appropriate to knowledge management in a technological society
CISI	information retrieval systems in this review i present the measures to some extent in the terms of their originators and to some extent in common terms which will make it easier to compare and contrast them with the measure proposed here
CISI	science growth and change more and more examples accumulated of highly variable growth rates and of their influence on scientific careers gradually the study began to incorporate calculations of the effects of variable growth on a wide range of scientific concerns studying teaching research publishing citations the basis of scientific prestige promotions unemployment it became apparent that generally unsuspected forces have a powerful influence on the careers of scientists and everyone else enmeshed in rapid change this book presents some evidence for change and speculates about many effects it also makes a beginning toward understanding the forces that cause and do not cause change it may provide some solace for those in dormant fields who have wondered why life has passed them by it may perhaps make a few highly successful scientists a little more modest most of all it may guide those who still have a choice   and so have we all
CISI	science and information theory a new scientific theory has been born during the last few years the theory of information it immediately attracted a great deal of interest and has expanded very rapidly this new theory was initially the result of a very practical and utilitarian discussion of certain basic problems how is it possible to define the quantity of information contained in a message or telegram to be transmitted how does one measure the amount of information communicated by a system of telegraphic signals how does one compare these two qualities and discuss the efficiency for coding devices all of these problems and many similar ones are of concern to the telecommunication engineer and can now be discussed quantitatively from these discussions there emerged a new theory of both mathematical and practical character this theory is based on probability considerations once stated in a precise way it can be used for many fundamental scientific discussions it enables one to solve the problem of maxwells demon and to show a very direct connection between information and entropy the thermodynamic entropy measures the lack of information about a certain physical system whenever an experiment is performed in the laboratory it is paid for by an increase of entropy and a generalized carnot principle states that the price paid in increase of entropy must always be larger than the amount of information gained information corresponds to negative entropy a quantity for which the author coined the word negentropy the generalized carnot principle may also be called the negentropy principle of information this principle imposes a new limitation on physical experiments and is independent of the well known uncertainty relations of quantum mechanics
CISI	two paradigms for scientific knowledge the growing interest in the sociology of science makes the publication of this collection of papers particularly timely because in broad outline it deals with the clash which occurs when the sociological approach makes incursions into the field normally occupied by philosophers of science
CISI	is a scientific revolution taking place in psychology   doubts and reservations we were introduced by kuhn to the notion of scientific progress as a series of qualitative changes each involving the overthrow of a prevailing paradigm of thought by a new paradigm which alters the whole perspective of a science palermo has appropriately summarized kuhns analysis it seems if we judge by constant citations of kuhn and the references to paradigms crises and revolutions among scientists and philosophers that he has induced a novel self consciousness about the growth of scientific knowledge and the nature of cumulativeness in the expansion of understanding   and not least among psychologists this may be in small part though i doubt it because one of psychologys concerns is the empirical study of the growth of knowledge jean piaget whose influence in some quarters has now become so great that he is hailed as a revolutionary in those quarters has for several decades been developing a theory of the growth of knowledge   or if you insist of the development of cognition   which like kuhns account in his preface kuhn acknowledges illumination from piaget eschews accumulation and posits a sequence of qualitative changes each of which completely reorganizes thinking
CISI	the development of specialities in science the case of x ray protein crystallography this paper discusses the intellectual structure of a scientific specialty in great detail
CISI	the structure of scientific literatures i identifying and graphing specialities in this paper we report a first experiment using a new computer based technique to identify clusters of highly interactive documents in science we contend that these clusters represent the scientific specialties which currently exhibit high levels of activity this technique we believe opens the way to a systematic exploration of the entire specialty structure of science including both the internal structure of specialities and their relationship to one another
CISI	poppers mystification of objective knowledge for popper science is the very epitome of objective knowledge the central papers of his latest book argue and elaborate on this theme he says all work in science is work directed towards the growth of objective knowledge we are workers who are adding to the growth of objective knowledge as masons work on a cathedral i will first make some preliminary points about the word objective this will give substance to issues which are in danger of becoming too rarefied second i will outline poppers account of objectivity third i will argue that despite the value of what he says his approach is seriously misleading i will propose a formula for systematically transforming poppers theses and exposing what is important in them this transformative method points the way towards an entirely different conception of what makes knowledge objective
CISI	the scientific community this work is concerned with the influence of scientific colleagues on the conduct of one anothers research with few exceptions the discussion is limited to basic research in experimental sciences with well established theories in this type of research the scientific community is relatively autonomous and the group of colleagues is the most important source of social influence on research colleagues influence decisions to select problems and techniques to publish results and to accept theories
CISI	scientific knowledge this is an essay in the sociology of scientific knowledge written with the sociology of knowledge and culture generally very much in mind as a sociological study it is unusual in that the form and content of scientific knowledge is the main concern and not its organization or distribution
CISI	scientific management of library operations this book is intended both as a textbook for library school students and a handbook for practicing librarians it will acquaint the former with the basic tools of the management analyst and will aid the latter in improving their present systems the major analysis techniques are described in step by step detail with a wealth of illustrations and library examples
CISI	scientific and technical libraries their organization and administration the book is designed to serve multiple purposes first the needs of practicing librarians particularly those who are just beginning their careers and require a general guide and source of operational and bibliographic information have been given special consideration a second purpose is to provide a textbook for library school and other advanced students whose interests are oriented toward the literature of the life and physical sciences the book could also help persons in management positions of organizations in which the establishment of a library is contemplated presenting if only from a review of the contents the scope of such a department finally it should be a good resource for library consultants engaged in assisting management to make the right decisions the requirements of all of these audiences have been assessed and endeavor made to meet their somewhat varied requirements
CISI	scientific and technological communication my objective in this work has been to try to get at the fundamental aspects of the elements and media of scientific and technological communication and to describe the critical issues involving them as well as the opportunities and techniques for exploiting them which hopefully could aid both the users and the handlers of these important resources
CISI	scientists in industry this study analyzes relations between professional employees the professions to which they belong and the organizations for which they work
CISI	scientists in organizations productive climates for research and development this book is addressed to scientists and engineers to administrators of research and development and to all others who are concerned about the effects of organizations upon the work of their members this book is one of the first major studies to examine the relationship between a scientists performance and the organization of his laboratory unlike many previous expositions about the best environment for technical people the findings resulted from extensive analysis of factual data from a wide range of research personnel work progressed over the next four years and a number of intriguing results began to emerge but as these were discussed with other investigators studying different kinds of r d laboratories discrepancies appeared it became clear that a broader study was needed before one could be sure what constitutes a stimulating environment for research personnel we set out to design a study in which standardized instruments would be administered to scientists and engineers in several types of laboratories
CISI	selecting materials in reality the building and shaping of the collection is the heart of librarianship involving the essential philosophy of the profession not only is it one of the most fascinating tasks in the intellectual world but book selection is the most important most interesting and most difficult of the professional librarians responsibilities true ready made lists of the best books need not be ignored but they have to be evaluated thoroughly and used only insofar as they prove helpful
CISI	issues in semantics the present collection of articles discusses three basic problems the typological classification of information retrieval languages the formal method of lexical semantic research and textual semantics problems connected with lexical word meaning the building up of semantic fields using computers and automatic indexing are considered
CISI	serial publications this book has been designed as a theoretical and practical introduction to the library aspects of serial publications these publications are now so profuse and at the same time so significant for library purposes that librarians generally should have a good grasp of their nature and of the modes of controlling them like rare books serials give rise to frequent and sometimes intricate technicalities with which not only specialists but also head librarians department heads and others should be acquainted since serials are part and parcel of the workday library
CISI	simulation teaching of library administration the underlying concepts of simulation and experimential teaching methods presented in this book have been borrowed from other fields   business governmental and education administration primarily the values for library educators are not hypothetical however for the methodology has been successfully used over a period of time by a number of teachers and in a variety of educational settings related to career training for librarians neither is the approach overpersonalized much of the telling is in personal terms in order to limit generalization to induce acceptance of responsibility and to provide concrete examples in terms of teaching library administration the assumption is that it will be easier for library educators to react creatively to methodological discourse couched in library science terms than if the same methodology were described in terms of high finance international politics militarism or secondary school planning
CISI	dictionary of terms in information theory this dictionary contains 3035 terms in information theory its system of methods and practice each terms give an interpretation in russian and the equivalent term in english the dictionary has alphabetical indexes of terms in both languages and a list of abbreviations
CISI	the smart retrieval system experiments in automatic document processing the automatic smart document retrieval system was designed at harvard university between 1961 and 1964 and has been operating of ibm 7094 and 360 equipment both at harvard and at cornell university for several years the system takes documents and search requests in the natural language performs a fully automatic content analysis of the texts using one of several dozen programmed language analysis methods matches analyzed documents with analyzed search requests and retrieves for the users attention those stored items believed to be most similar to the submitted queries
CISI	developments in data analysis the last ten years have witnessed rapid and often radical changes in computer programming systems for social science data at least a dozen different program packages collections or systems not to mention hundreds of individual programs have emerged by now and are in use by social scientists at universities and research centers all across the country it is probably safe to say that the bulk of these systems and programs represent the individual efforts of a small group working at one institution often operating under a relatively restricted set of research and computing assumptions this parochial tendency has left students and researchers with the often bewildering and always time  consuming problem of learning new procedures for processing their data each time they change institutions or each time the institution changes computers
CISI	the social construction of reality a treatise on the sociology of knowledge the present volume is intended as a systematic theoretical treatise in the sociology of knowledge it is not intended therefore to give a historical survey of the development of this discipline or to engage in exegesis of various figures in this other other developments in sociological theory or even to show how a synthesis may be achieved between several of these figures and developments nor is there any polemic intent here critical comments on other theoretical positions have been introduced not in the text but in the notes only where they may serve to clarify the present argument
CISI	the social function of science the events of the past few years have led to a critical examination of the function of science in society it used to be believed that the results of scientific investigation would lead to continuous progressive improvements in conditions of life but first the war and then the economic crisis have shown that science can be used as easily for destructive and wasteful purpose and voices have been raised demanding the cessation of scientific research as the only means of preserving a tolerable civilization scientists themselves faced with these criticisms have been forced to consider effectively for the first time how the work they are doing is connected with the social and economic developments which are occurring around them this book is an attempt to analyze this connection to investigate how far scientists individually and collectively are responsible for this state of affairs and to suggest what possible steps could be taken which would lead to a fruitful and not to a destructive utilization of science
CISI	social mobility in industrial society in the present study professors lipset and bendix cast doubt on the validity of a number of widely accepted generalizations relating to social mobility particularly 1 that there has been substantially less mobility in europe than in the united states 2 that social mobility tends to decline as industrial societies mature and 3 that opportunities for entrance into the business elite become more restricted with mature industrialization in a careful analysis of the existing literature the authors marshal an imposing array of evidence in support of their major thesis that social mobility is an integral and continuing aspect of the process of industrialization
CISI	social organization of hamadryas baboons baboons have adapted to a variety of habitats ranging from west african rain forests to semidesert areas on the coast of the red sea while all baboons are morphologically adapted to life on the ground some species have become more independent of trees than others in a rough ecological series we find on one end the forest dwelling west african species mandrillus leucophaneus m sphinx papio papio none of which has so far been studied in the field the first step into open country is realized by the savanna baboons of south and east africa including from south to north the species papio ursinus cynocephalus and anubis their social organization and its ecological context have been subject to long range field work by hall 1962 a b in south africa by devore 1962 in kenya and by altmann and altmann in preparation in kenya ad tanzania in both regions the groups can range far into the open grassland but at night they withdraw to high trees or as in the cape region to vertical cliffs
CISI	the social psychology of organizations in our attempts to extend the description and explanation of organizational processes we have shifted from an earlier emphasis on traditional concepts of individual psychology and interpersonal relations to system constructs the interdependent behavior of many people in their supportive and complementary actions takes on a form or structure which needs to be conceptualized at a more appropriate collective level classical organization theory we found unsatisfactory because of its implicit assumptions about the closed character of social structures the development of open system theory on the other hand furnished a much more dynamic and adequate framework hence our effort in the pages that follow is directed at the utilization of an open system point of view for the study of large scale organizations
CISI	cognitive technical and social factors in the growth of radio astronomy we have tried in this paper to describe some of the main features of the emergence and growth of radio astronomy with special reference to the crucial developments occurring in the uk much of what we have written above needs to be discussed in the light of current theories about the nature of scientific growth and compared with data from other case studies
CISI	career contingencies and the fate of sociological research during the past three hundred years the journal article has become the main institutionalized form of formal scholarly communication potential contributions to a discipline acquire credibility because they have been published in a reputable journal zuckerman and merton 1971 who published what and where therefore becomes a central question in the understanding of scholarly and in particular scientific disciplines there have recently been a number of investigations concerning the career of such publications this career i suggest can be conceptualized into three stages 1 pre publication here the scholar writes the article circulates it to colleagues and perhaps presents it at formal and informal meetings garvey lin and nelson 1971 2 publication here the article is submitted to one or more journals for publication consideration zuckerman and merton 1971 3 post publication here colleagues either ignore the published article or reward it through citations to it in their own work the practice of citing a colleagues work is perhaps the main way in which scholars indicate what they consider to be a contribution to their discipline
CISI	exit voice and loyalty further reflections and a survey of recent contributions my book exit voice and loyalty responses to decline in firms organizations and states was published in l970 reactions to it and applications of its concepts have been fairly numerous and i have myself had quite a few afterthoughts it will therefore be difficult to bring these matters together in a passably structured paper in the following i shall limit myself to four broad areas of inquiry which have been so arranged that my own further reflections figure rather prominently though by no means exclusively in the first two sections while the latter two are more heavily weighted with reports and comments on the research and contributions of others
CISI	social stratification in science in recent years social scientists have given increased attention to problems of inequality justice and discrimination in american society the influence of ascribed statuses on the life chances of individuals is being studied in an effort to estimate the fairness of social institutions in rewarding talent social scientists are trying to determine the extent to which so called irrelevant characteristics influence the ways in which people are judged by social institutions and eventually reach social positions in the hierarchies of income prestige and influence of the major institutions in american society science has received perhaps the least systematic attention little is known about how scientists achieve positions of renown this book examines several aspects of a single basic question is the stratification of individuals in science based upon the quality of scientific performance or does discrimination obtain in the processes of status attainment a more technical way of putting the same question would be to ask whether universalistic and rational criteria predominate as the basis for recognition in the social system of science
CISI	notes and letters we tried to concentrate on a few variables that might define the nature of a citation and to keep the rest of the variables constant in particular we used references in articles in a single journal in a single specialty of a single branch of science and in a narrow time period specifically we investigated 30 articles dealing with theoretical high energy physics and published in physical review in the years 1968 to 1972 inclusive
CISI	the social system of science this book is an exercise in sociological theory  building it attempts to develop a theory of the social organization of science i have tried to indicate its possible broader relevance by pointing out certain basic parallels between the social system of science and other social systems within society i hope further that the approach used   even if not the specific conclusions i have drawn from it   may be useful in bridging the gap that seems now to exist between those sociologists who are concerned with society as an entity and who analyze social behavior in terms of its consequences for society as a whole and those sociologists who are concerned first of all with the motives attitudes and goals of the individual participants in these patterns of social behavior my approach hopes to answer the question of why it is that most individuals most of the time come to want to do what it is that society needs them to do only when we can answer this question satisfactorily can we develop a sociology capable of providing both prediction and meaning
CISI	social theory and social structure of the four chapters added to this edition two come from published symposia one of which is out of print and the other of which i am told is nearing that same state of exhaustion this chapter sets forth the concept of the influential  identifies two distinctive types of influentials the local and the cosmopolitan  and relates these types to the structure of influence in the local community the second of these chapters contributions to the theory of reference group behavior draws upon the ample evidence provided by the american soldier to formulate certain conditions under which people orient themselves to the norms of various groups in particular the groups with which they are not affiliated the other two chapters added to this edition have not been published before the first of these continuities in the theory of social structure and anomie tries to consolidate recent empirical and theoretical analyses of the sources and consequences of that breakdown of social norms which is described as anomie the second continuities in the theory of reference groups and social structure tries to bring out some of the specially sociological as distinct from the socio psychological implications of current inquiries into reference group behavior the intent is to examine some of the theoretical problems of social structure which must be solved before certain further advances can be made in the sociological analysis of reference groups
CISI	communication nets in science status and citation patterns in animal physiology by virtue of its peculiar links with the reward system in science the communication system plays a central part in the maintenance and growth of science it is the means by which the individual scientist relates to the social system he publishes his work to gain recognition and reads the publications of others to maintain his knowledge the formal communication system also forms the basis for the allocation of rewards instrumental and consumatory thus it is a means of exercising social control the informal communication system although important is the distaff side its recognition is personal with more immediate and consumatory rewards legitimation of objective or methods of work is rarely given by the social system through informal systems of communication though it is growing in importance as an information dissemination system
CISI	problem areas and research networks in science a general account is presented of the emergence growth and decline of scientific research networks and their associated problem areas research networks are seen to pass through three phases the first exploratory phase is distinguished by a lack of effective communication among participants and by the pursuit of imprecisely defined problems the second phase is one of rapid growth associated with increasing social and intellectual integration made possible by improved communication an increasingly precise scientific consensus gradually emerges from a process of negotiation in which those participants who are members of the scientific elite exert most influence but as consensus is achieved the problem area becomes less scientifically fruitful and as the network grows career opportunities diminish consequently the third final phase is one of decline and disbandment of the network together with the movement of participants to new areas of scientific opportunity
CISI	the seven sexes a study in the sociology of a phenomenon or the replication of experiments in physics the replication of scientific experiments is discussed stressing the problem of communication between the originator of an experiment and a scientist intending to replicate it models of communication are set up with reference to established fields a more marginal field is then investigated in the light of these models and it is concluded that scientists in the latter field should not be seen as engaged in replicating original experiment but in negotiating the rules of replication and hence the nature of the phenomenon under investigation
CISI	some correlates of a citation measure of productivity in science the science citation index provides an easy way to derive criterion measures of scientific accomplishment measures derived from citation counts the principal criterion have high face validity these criterion measures are found to have a low but positive correlation with the quality of scientists graduate education and no relation to his measured iq score plans for future research on the correlates of scientific productivity are briefly discussed
CISI	competition and social control in science an essay in theory construction social control in science operates through the process in which the colleague group validates individual scientists contributions to knowledge to the laymen who provide support and rewards for science descriptive research in various areas of the sociology of science may be brought together into a causal model which relates competitive conditions within colleague groups to variations in scientific productivity methods values and organizational structures
CISI	patterns of intellectual influence in scientific research a widespread conception of the development of science holds that the great discoveries are a result of the cumulative work of a vast number of scientists those historians and philosophers of science who express this point of view see the scientist who produces pedestrian research as an integral part of the developmental process the great men of science stand atop a pyramid of less distinguished and to a large extent invisible scientists an alternative hypothesis holds that relatively few scientists are responsible for advance in science and that in the broader historical perspective most of the eminent scientists even of the calibre of nobel laureates and national academy members of today are the pedestrians of history this paper attempts to put these conflicting ideas to empirical test for the field of physics three independent sets of data are analyzed one is drawn from a stratified random sample of american academic physicists a second from a subjective evaluation of significant contributions to recent physics a third from a set of papers cited in the physical review all three sets of data indicate that there is a sharp stratification in the use of work published by various types of scientists the data support the hypothesis that the physicists who produce important discoveries depend almost wholly on the research produced by a relatively small number of scientists the implications of these findings for the social structure of science are discussed and areas for necessary future research are suggested
CISI	inputs outputs and the prestige of university science departments this paper reports correlates of departmental prestige american council on education rating of the quality of graduate faculty 1966 for a sample of 125 departments in mathematics physics chemistry and biology the analysis mostly uses multivariate linear regression large and significant correlations with departmental prestige exist for measures of department size research production research opportunities faculty background including quality of phd university and faculty awards and offices combinations of from six to nine indicators of these variables account for about three fourths of the variance in departmental prestige when other types of variables are held constant indicators of all except research opportunities remain significantly associated with departmental prestige correlations of prestige with rates of inbreeding and the proportion of foreign doctorates are discussed differences in the correlates of prestige are small among the four fields studied it is shown that prestige is correlated with average amount of informal scientific communication and with departmental morale even after possible confounding variables are held constant
CISI	sociology and modern system theory this book is intended as an exploratory sketch of a revolutionary scientific perspective and conceptual framework as it might be applied to the sociocultural system this point of view and still developing framework as interpreted here stems from the general systems research movement and the now closely allied fields of cybernetics and information or communication theory the principal goal of the book is to bring to the attention of a larger number of social scientists particularly sociologists the wealth of principles ideas and insights that have already brought a higher degree of scientific order and understanding to many areas of biology psychology and some physical sciences to say nothing of the applied areas of technology to which they are essential
CISI	sources of information in the social sciences documentation in the social sciences is varied in form and content written for people in many walks of life and fills several miles of shelving in libraries that try to keep up with it graduate students who qualify for positions as professional librarians have to learn about this vast preserve and it is their need of guidance that explains the origin of this book the task of this book is to place in the readers hands a sort of chart and compass to use in finding his way around and learning how the system works for each subject the treatment falls into two parts first a specialist sought out for his grasp of the literature presents a bibliographical review of basic monographic works for a collection of substantive material this review is followed by a list of reference works informative annotations are provided for all works except those adequately explained by the title specialized works are included especially when they exemplify types of sources important for reference purposes first priority goes to works which may be looked upon as basic for a program of service to a general clientele made up of scholars students and the public at large if some stress falls on bibliographies it is because they serve as controls for opening doorways to even vaster information and to sources that are more obscure
CISI	soviet bibliography the first and most basic phase of research was the analysis of existing bilbiographic publications the chronicles of the all union book reserve viniti abstract journals publications of subject information centers and main libraries bulletins of new publications as well as the main current foreign bibliography on some branches of knowledge were considered after comparative analysis valuable data were obtained in the completeness of registration of literature and the efficiency of its reflection in different publications on the types of classificatory schemes and intermediate instruments on the quality of abstracts the merits and drawbacks of basic bibliographic publications were shown and recommendations for improving present bibliographic systems were suggested
CISI	the special cataloguing we feel meanwhile that many materials can be covered by general or representative principles and rules the content of this book can be viewed as of two types firstly the first and last chapters deal with special materials in general the former dealing with basic cataloguing principles and problems and the latter with the ultimate application of such principles as manifested by the concept of the multi media catalogue and as aided by the computer secondly in between come chapters dealing with individual categories of materials in detail each category receives two types of treatment first the problems of both approaches and description are examined as they apply to the particular medium second the solutions put forward by representative codes are summarized and commented upon
CISI	evolving the 90 pharmaceutical library the growing need for library space dictated a quantitative study to ascertain user requirements a monitoring operation has been established whereby data are continuously collected on the use made of periodicals shelved in a restricted storage area the data obtained from photocopy request forms identify the core collection of journals which satisfies 90 of our library research requirements
CISI	how to survive in industry cost justifying library services two services provided by the boeing co aerospace group library   literature searches and reference publication identification activities   were evaluated by written and oral surveys of the librarys users the survey technique and cost savings reported by the two studies are discussed in addition to the beneficial impact of the survey results on high level corporate management
CISI	cooperation between academic and special libraries the concept of library cooperation is examined generally and that among academic libraries among special libraries and between academic and special libraries as reported in the recent literature the question of the probable future of cooperation between academic and special libraries is addressed and possible support mechanisms for establishing soundly based cooperative undertakings are suggested
CISI	rational selection of primary journals for a biomedical research library the use of secondary journal citation after considering several different methods it was concluded that primary journals for coverage of a given field can be selected rationally on the basis of their citation frequencies in an appropriate secondary journal results obtained on the example used rehabilitation as cited in index medicus during the years 1968 1971 were similar to those from five other fields in that the number of journals required for each percent gain in literature coverage increased exponentially as the percentage of literature itself increased as a consequence library coverage of any particular field can be specified as a function of its budgeting commitment so that the maximum percent coverage will be obtained for each dollar spent
CISI	the scientist versus machine search services we are the missing link to take advantage of computerized data bases to improve their services to scientists without incurring prohibitive in house expense the librarians at the boulder laboratories have campaigned to increase awareness and utilization via personal interviews seminars surveys and critiques data bases most studied were ddc nasa sie asca and the university of georgia the conclusions 1 the scientist needs continuous personal assistance by a librarian or information specialist in order to make effective use of data bases 2 as local retailer the librarian has an accordingly important role to play now and in the future a role at present generally ignored
CISI	freud frug and feedback people ask one another am i communicating the question should be what do you think i am communicating the answer would be surprising librarians are in the communications business theories of nonverbal communication and role can be adapted to a library situation applied they would provide a basis for improving librarian library user communication awareness of feedback is the key to this improvement preliminary investigations underway at the university of southern california indicate the reference encounter provides a investigative approach in which this key can be utilized to enhance communication
CISI	system design evaluation and costing the word system as applied to information programs and activities is one which is very foggily defined the purpose of this paper is to help clarify the concept and discuss it in the context of the librarians conventional planning and administrative activities this is done through a narration of the step by step procedures followed in the conceptualization and design of an actual library and information program the steps involved are the following definition of the purpose of the program and financial and administrative constraints on its design and operation as envisaged by management a user study to determine needs and preferences of the presumed audience of the program analysis and definition of program performance requirements selection of methods and mechanisms for implementing performance requirements conceptualization and documentation of program design evaluation of design modification and completion of design two basic principles that are discussed and emphasized are the need to define what the program should be doing and what it should not be doing and the need and means for determining real as opposed to apparent costs in the design process
CISI	time and motion study of library operations application of standard work measurement techniques to acquisitions cataloguing and circulation functions of an aerospace library is described sample of a representative production unit in included a 38 per cent saving in manpower without loss of quality effort proves the library environment responds admirably to this management tool
CISI	program planning and budget theory improved library effectiveness by use of the planning programming budgeting system libraries have a great need to participate more effectively in decisions that influence their capacity to serve their users this paper presents a means toward that end the relatively new planning programming budgeting system is described in the context of its proven utility in the department of defense and of its growing utility in the civil sector of organizations it describes the systems background its implementation in the federal government its spread into non federal sectors and the systems methods including systems analysis applied economics and quantitative reasoning the paper includes illustrative example of results needed for decision making by managers and basic guiding principles for ppbs application
CISI	user needs and their effect on information center administration a review 1953 66 a determination of the needs of users is absolutely essential to the management of an information center various techniques of doing this e g interview diary questionnaire etc are detailed along with their limitations some specific user need studies are described with their significant results interactions between users and an information system are described finally all of these factors are considered in assessing the user needs that might be used to properly manage information centers
CISI	the can sdi project th sdi program of canadas national science library the national science library is not a library in the conventional sense of the word but rather an information transferral agency its activities are designed to provide the canadian scientific and industrial communities with direct and immediate access to the publications and information required in their day to day work through co operative measures with both national and international information agencies the nsl serves as the focal point of a national scientific and technical information network the library employs a variety of mechanized techniques to facilitate the storage retrieval and dissemination of information during the past three years it has operated an sdi service using ct and isi tapes in november 1968 this sdi service which had been limited to meeting the needs of approximately 170 scientists in the ottawa area was expanded to provide a national sdi service the author describes the evolution of these services from the local to national level outlines basic techniques describes the successes and failures of the system and indicates future developments
CISI	current awareness publications an evaluation three types of current awareness publications are defined in terms of their generation and distribution characteristics these types are the sdi type the intermediate type such as nasas scan program and the unselected type such as the usual library accession list a fourth type the indexing and abstracting journal is defined but not related to the other three types the three current awareness publications are shown to have a relationship in terms of the number of requests they can produce from a given set of references or notices the sdi system will produce about one request from ten notices the intermediate type about one request per hundred notices ad the unselected type one request per thousand notices despite the differences in the number of notices to generate one request the cost to produce one request is about the same for the three types of tools also the usage of these tools is related to the amount of user time available and a curve is presented based on various assumptions to define this relationship
CISI	the new york times information bank the new york times information bank is described in detail schedules to be in operation in 1972 this project makes available abstracts of newspaper articles for on line search and retrieval combined with microform copies of the original articles
CISI	centralization vs decentralization a location analysis approach for librarians an application of location theory to the question of centralized versus decentralized library facilities for a university with relevance for special libraries is presented locating university libraries near classrooms offices and dormitories requires a larger budget than combining these libraries into a centralized facility yet there is a cost to the university community which does not appear in the university budget   a cost in time energy and decreased use resulting from locating the library a longer distance from users the analysis provides models for a single library for two or more libraries or for decentralized facilities
CISI	the computerized file management system a file management system can provide a powerful search tool for a library reference group the system described produces both current awareness and retrospective searches from several diverse data bases the same query language can be used to interrogate all data bases in either on line or batch mode searches can be made for any word word root phrase or number in any part of any entry citations selected by coordination of terms can be either printed or used to custom make new machine readable files costs are reasonable an average batch mode search requires 11 seconds of cdc 6600 time
CISI	a campus based information center several features of the university of georgia information dissemination center including current awareness or sdi and retrospective search services the information specialists who provide the interface between the user and the computer system and an experimental network linking individual centers are discussed a survey which assessed the impact of the services on the information habits of the university users is also discussed over 97 of the survey respondees indicated that the services had contributed to their professional activities some users reported that the service had been a method of bypassing library reference works others indicated that the service had brought them back into the library and made them aware of information sources previously unknown to them
CISI	computer based bibliographic retrieval services the information dissemination center has emerged as a broker or retailer for computer based information retrieval services interfacing with both the tape suppliers and with users of the search services five areas which impact the centers interface with these two communities are discussed the nature of the data bases which are available for search retrieval results and factors which affect them the timeliness of services costs and prices and practical operational considerations related to library interests comparison shopping between centers is advised as centers differ considerably in the services which are offered the data bases which are available the experience of the information specialists who construct search profiles pricing structures which are used and the prices which are charged implications of the growing trend toward licensing and leasing information resources especially magnetic tape services are discussed briefly
CISI	journal usage survey method and application a survey of the r e gibson librarys journal collection was conducted to determine 1 which journal titles could be discontinued 2 which journal holdings could be moved to remote storage and 3 which journal holdings could be converted to microfilm totals were maintained for three areas of journal usage according to 1 the number of times patrons used current issues 2 the number of times the journal issues were reshelved by library staff and 3 the number of times that journals were cited in articles by applied physics laboratory apl authors the survey resulted in a 9 6 reduction in journal subscriptions which in effect added 7 5 additional shelf space in which to display journals further studies of the accumulated data are being made to determine which holdings will be sent to a remote storage area which is under construction the survey data have been and will continue to be consulted before any journals are converted to microfilm
CISI	computer literature searches in the physical sciences selected computerized current awareness services and literature searchs in physical sciences are listed the information given includes type of literature in each data base time period covered prices and sources of availability
CISI	computer output microfilm computer output in microfilm or microfiche form com rather than computer printout and conventional forms of reproduction is one possible way special librarians can reduce their costs space needs and time lags com is described among with the equipment needed where to find it and experiences of one special library possible savins are compared with additional reading and special reproduction equipment required as well as the advantages and disadvantages to be weighed in deciding on com
CISI	a comparison of manual and machine literature searches the noaa erl library in boulder colorado performed a sample of six literature searches in an effort to gain management support for searches prior to launching research projects it was found that manual searches are very time consuming and in our opinion can better be done by persons with subject background the machine searches furnished a higher percentage of unrelated materials however little staff time is required to obtain them lacking qualified persons to do literature searches either in the library or in the research groups greater use should be made of the available computerized searches
CISI	how do scientists meet their information needs a survey of the information use patterns and communication practices of academic physicists in the greater boston area reveals that academic physicists rely heavily on formal and informal sources of information their use of formal publications concentrates on a small number of journal titles time and location factors play an important role in their information seeking and gathering a considerable number of the physicists surveyed do not seek librarians help when searching for information in the library although libraries have been considered largely as storehouses of materials and librarians organizers of these materials more active roles for librarians are possible
CISI	cost comparison of manual and on line computerized literature searching cost and searching time comparisons are made between manual and on line literature searches the formula ctotal t x csum p is presented which captures all on line cost factors a minimum cost of 1 00 per minute of on line searching is derived average searching time for manual searching is 22 hours at a total cost of 250 for on line it is 45 minutes at total cost of 47 00 it is pointed out that most reported low on line search costs fail to account for all cost factors figures are those prevailing at the time of writing
CISI	user criteria for selection of commercial on line computer based bibliographic services many interrelating factors with examples have been cited as criteria for selection and proper use of commercial on line computer based bibliographic services in an industrial environment these complex factors have been analyzed under the needs of the users the selection of hardware the selection of mode of transmission the selection of vendors and systems the selection of data bases the development of productive search strategy and the considerations of measures to test it the attitude of management and the interaction of the user with the system in the authors experience exhaustive and comprehensive searches were minimally requested thus posing questions for determining measures of evaluation
CISI	criteria for evaluation and selection of data bases and data base services libraries as potential users of bibliographic data base services will need to evaluate not only the contents of the many data bases available but the different services provided by various processing centers criteria for selection of data bases and data base services such as searching features logical capacity document delivery output format and medium and costs are examined
CISI	on line reference retrieval in a public library there are many useful computer readable data bases that are accessible only to major governmental units universities or industrial organizations an experiment is described in which the public library is used as a linking agent between the public and such data bases retrieval terminals have been placed in four public libraries in northern california to provide access to sixteen different data bases the first year of this two year experiment is described and some of the technical organizational and economic aspects of the study are reviewed rapid acceptance of the system during this initial no cost period has been achieved and useful evaluative data have been obtained
CISI	standards for library service an international survey in recent years it has become recognized that a countrys documentation and library services indispensable for all forms of economic social and cultural development should be considered as one co ordinated information system and accordingly included in any national development plans however planning can only be carried out if the necessary statistical data and other information are available unesco therefore concluded a contract in 1968 with the international federation of library associations ifla for a survey of standards for library services currently recommended for libraries of all types in different countries the work was entrusted to f n withers a research fellow at the polytechnic of north london school of librarianship united kingdom
CISI	state library policy state library policy is the focus of this study the approach to policy is framed in the broadest possible terms currently permitted by empirical research in the examination of governmental policy formation a major purpose of the study is to analyze state library policy in relationship to the environment which provides the backdrop for its formation and maintenance the authors see this ambitious effort as a pioneering thrust in library research and not as the final work on library policy
CISI	statistical bibliography in relation to the growth of modern civilization the following pages form the concluding portion of four lectures delivered by me in the university of cambridge as sandars reader in bibliography 1921 as the two pairs of lectures appeal to widely different classes of the community i have decided to print them separately though the underlying theme is the same viz the need for uniformity in book classification as a preliminary to co operative action in library administration and bibliography book classification is shelf classification and shelf classification carried to its furthest limits leads necessarily to uniformity in the extension and definition of its classes add to this a chronological order of books in their classes and your scheme of classification acquires a new value for it presents for each period a bibliographical counterpart of the corresponding growth of the activities of the human mind my first two lectures dealt with this thesis in its practical application to library work and the compilation of subject bibliographies here statistical bibliography is considered in relation to the growth of modern civilization strictly speaking the province of statistical bibliography ends with the presentation of the figures compiled their final interpretation should be left to those possessing the necessary qualifications i am therefore conscious that in attempting to furnish some explanation of the interrelations of the various factors which are associated with the growth of modern civilization i have outstripped the limits of bibliographical propriety on this count i offer no defense
CISI	statistical methods for the study of lexicon this book studies the qualitative relations between text and dictionary compilation chapter i considers general questions related to the compilation and use of frequency vocabulary a new zipfs law chapter iii considers various ways of describing the statistical properties of a text and its lexicon and presents the results of the authors research on the statistic structure of pushkins lexicon chapter iv considers methods for comparing the vocabulary of texts a new method for comparing word lists is suggested which is then used for comparing word lists from the different geures in pushkins works
CISI	statistics and semantics this monograph is one of the few works in which the possibility of studying semantics using statistical methods is proven with actual research the semantic field of words denoting color in english french russian and ukranian was chosen as a representative semantic object the applied aspects of this work are particularly important the application of those methods tested by the authors for solving problems of automatic information processing as well as in language translation and instruction
CISI	strategies for change in information programs the diverse energies framing library media information futures affect everyone who needs to know to understand to do and to grow this collection of articles and essays represents the many concerns and insights that are helping shape the future a future in which library media information programs can play a vital role as they attempt to reach out to people everywhere
CISI	a strategy for public library change the fate of the american institutional phenomenon the public library is in question its position has never been truly secure in terms of general use or public support except in the large cities until recent years and for a few short periods of marked progress countrywide
CISI	structural models an introduction to the theory of directed graphs the purpose of this book is to present an introduction to a body of mathematics concerned with the abstract notion of structure its preparation has been motivated by the belief that knowledge of the mathematics of abstract structures will be of value to investigators interested in various kinds of empirical structures the mathematics with which we are concerned is known as the theory of directed graphs or more briefly as digraph theory it deals with abstract configurations called digraphs which consist of points and directed lines when these terms are given concrete referents digraphs serve as mathematical models of empirical structures and properties of digraphs reflect structural properties of the empirical world since the same mathematical terms can be given a variety of empirical meanings digraph theory has applicability to many different fields of investigation
CISI	the structure of scientific revolutions the essay that follows is the first full published report on a project originally conceived almost fifteen years ago at that time i was a graduate student in theoretical physics already within sight of the end of my dissertation a fortunate involvement with an experimental college course treating physical science for the non scientist provided my first exposure to out of date scientific theory and practice radically undermined some of my basic conceptions about the nature of science and the reasons for its special success
CISI	the structure of scientific revolutions the essay that follows is the first full published report on a project originally conceived almost fifteen years ago at that time i was a graduate student in theoretical physics already within sight of the end of my dissertation a fortunate involvement with an experimental college course treating physical science for the non scientist provided my first exposure to out of date scientific theory and practice radically undermined some of my basic conceptions about the nature of science and the reasons for its special success those conceptions were ones i had previously drawn partly from scientific training itself and partly from a long standing avocational interest in the philosophy of science somehow whatever their pedagogic utility and their abstract plausibility those notions did not at all fit the enterprise that historical study displayed yet they were and are fundamental to many discussions of science and their failures of verisimilitude therefore seemed thoroughly worth pursuing the result was a drastic shift in my career plans a shift from physics to history of science and then gradually from relatively straightforward historical problems back to the more philosophical concerns that had initially led me to history except for a few articles this essay is the first of my published works in which these early concerns are dominant in some part it is an attempt to explain to myself and to friends how i happened to be drawn from science to its history in the first place
CISI	structure of discourse this monograph studies the external links between the sentences within a paragraph two basic problems are solved a formal apparatus for deriving simplified versions of the texts phrases is devised and the regularities in the formation of word strings are determined also considers future developments in the field of automatized abstracting
CISI	studies in ethnomethodology in doing sociology lay and professional every reference to the real world even where the reference is to physical or biological events is a reference to the organized activities of everyday life thereby in contrast to certain versions of durkheim that teach that the objective reality of social facts is sociologys fundamental principle the lesson is taken instead and used as study policy that the objective reality of social facts as an ongoing accomplishment of the concerted activities of daily life with the ordinary artful ways of that accomplishment being by members known used ad taken for granted is for members doing sociology a fundamental phenomenon because and in the ways it is practical sociologys fundamental phenomenon it is the prevailing topic for ethno methodological study ethnomethodological studies analyze everyday activities as members methods for making those same activities visibly rational  and reportable for all practical purposes i e accountable as organizations of commonplace everyday activities the reflexivity of that phenomenon is a singular feature of practical actions of practical circumstances of common sense knowledge of social structures and of practical sociological reasoning by permitting us to locate and examine their occurrence the reflexivity of that phenomenon establishes their study
CISI	a study of the characteristics cost and magnitude of interlibrary loans in academic libraries the investigation of interlibrary loans among academic libraries was initiated by the interlibrary loan study committee of the association of research libraries it was seen as a fundamental first step toward the solution of current problems and the exploration of the means to improve interlibrary loan services nationally this report provides solid information that is basic to any future planning at the national level
CISI	a study of general categories applicable to classification and coding in documentation the rapid development of information retrieval methods since the last war   together with the development of systems using mechanical or electromechanical means punched cards for such purposes followed later by electronic retrieval computers   have led to transformations in the structure of classification or coding systems for books and documents generally speaking document specialists have tended to elaborate a large number of different codes usually totally unrelated to each other each conceived to meet the special documentation requirements of a particular organization this is farther than ever   at least to all appearances   from the original intention of 1895 of the founders of the institut international de bibliographie now known as the federation internationale de documentation i e the standardization of classification methods
CISI	subject analysis computer implications of rigorous definator subject analysis for information retrieval is an area which always seems deceptively simple to those without previous background in it however extensive their background in specific subject disciplines may be the basic requirement seems easy enough to structure the statement of a subject in such a way that it can be placed into and retrieved from an ordered file while attempts have been made to use simple non complex terms or even single words it always becomes evident that single words are often insufficient to express a subject and that some subjects are in themselves complex to express such subjects requires either that their constituent concepts    not words    be separated and then recombined or that only one part of the subject be shown the former solution requires that the indexer perform the necessary analysis and synthesis and then separate the constituents for the searcher to reassemble the latter forces the seeker of information to sort through many items to find those bearing on the complex topic he wants and ma require the indexer to decide under which part s of the concept an entry should be made
CISI	the subject approach to information the first edition of this book published in 1969 was prompted by changes in the library association syllabus which for the first time enables lecturers to treat classification and subject cataloging as different aspects of the same topic these changes coincided with the publication of the results of the cranfield project which showed clearly that all indexing languages are basically the same however although it was possible to teach these new approaches there was no one textbook which covered the subject approach in the way that i felt was needed the first edition was intended to fill this gap and its reception both in britain and abroad showed that it did indeed fulfill a real need it met with a very positive welcome from lecturers and   more importantly   from students particularly in the united states where british textbooks on classification had previously been regarded with something akin to suspicion as the dean of one american library school is alleged to have remarked what theory of classification 
CISI	subject catalogues heading and structure in 1955 the publications committee of the library association approached my chief mr a j wells with a request that he should write a book on subject cataloguing at the time mr wells was preoccupied with the inauguration of the british national bibliography card service and he made the suggestion which was agreed by the committee that i should undertake the task the result is scarcely an adequate substitute for the book which mr wells would have written nevertheless he has had a major part in shaping my views on subject cataloguing and in this sense the present book stems back to him though he might not subscribe to all the views now put forward
CISI	subject headings a practical guide the alphabetical subject catalog either self contained or as the subject element in the dictionary catalog is a later development that the systematic or classed catalog realkatalog catalogue raisonne in this country it has almost completely displaced the latter the principal classed catalogs now remaining are those of the engineering societies library in new york the john crerar library in chicago and the science and technology department of the carnegie library of pittsburgh there are nevertheless many things to commend the classed catalog rudolf kaiser sums up the argument between the classed and the dictionary catalog by stating that a library needs both and explaining that the subject index fills the need as far as an alphabetical catalog is concerned however his conclusion misses the mark since for one not completely the master of the system of classification there is no approach to the classed catalog save through an index yet the index is not in fact as complete and direct a guide to the subject content of the librarys collections as an alphabetical catalog rationally and fully cross referenced
CISI	survey of commercially available computer readable bibliographic data bases this document contains the results of a survey of 94 us organizations and 36 organizations in other countries that were thought to prepare machine readable data bases of those surveyed 55 organizations 40 in u s 15 in other countries provided completed camera ready forms describing bibliographic information about published literature the following types of data were requested for each data base name frequency of issue and time span covered by the data base name of organizations and individuals who can provide information on the data base subject matter and scope of data on the tape source of information in the data base journal articles reports patents monographs etc method s used for indexing or other types of subject analysis special data elements tape specifications density tracks labels etc availability of programs for retrospective searching and selective dissemination of information sdi type and cost of search services offered and availability and charges for data bases the information provided represents the status of these data bases as of november 1972 it is anticipated that libraries and other information centers will find this document helpful in selecting data bases for providing sdi retrospective search services and other bibliographic reference services to their users
CISI	survey of the interlibrary loan operation of the national library of medicine this paper reports a survey of the interlibrary loan operations at the national library of medicine the operations discussed here represent a significant departure from conventional interlibrary loan routines the substance of the present report pertains to the handling of interlibrary loans through the instrumentality of photoduplication this concept   providing photoduplicates of desired materials in lieu of loaning the originals   stems from thinking enunciated by atherton seidell a member of the friends of the army medical library who pioneered in the development of photoduplication services
CISI	switching and finite automata theory the subject of switching and finite automata theory needs no introduction it has become a part of every computer science and electrical engineering curriculum and rightly so it provides techniques useful in a wide variety of applications and helps develop a way of thinking that leads to understanding of the structure behavior and limitations and capabilities of logical machines in this book i have tried to cover the whole subject starting with introductory material and leading to the more advanced topics assuming a minimal technical background on the part of the reader i did not attempt to provide detailed techniques for the design of specific circuits but rather to formulate methods and to develop algorithms that can be applied to a broad class of problems for once such general principles are understood the relevance of specific procedures and their applicability to given problems are a matter of engineering decisions
CISI	syntactic structures this study deals with syntactic structure both in the broad sense as opposed to semantics and the narrow sense as opposed to phonemics and morphology it forms part of an attempt to construct a formalized general theory of linguistic structure and to explore the foundations of such a theory the search for rigorous formulation in linguistics has a much more serious motivation than mere concern for logical niceties or the desire to purify well established methods of linguistic analysis precisely constructed models for linguistic structure can play an important role both negative and positive in the process of discovery itself by pushing a precise but inadequate formulation to an unacceptable conclusion we can often expose the exact source of this inadequacy and consequently gain a deeper understanding of the linguistic data more positively a formalized theory may automatically provide solutions for many problems other than those for which it was explicitly designed obscure and intuition bound notions can neither lead to absurd conclusions nor provide new and correct ones and hence they fail to be useful in two important respects
CISI	systematic analysis of university libraries as the administrators and librarians on every campus know limited resources force hard choices among many desirable schemes for expanding and improving library facilities what percentage of new books should be acquired how much service should be provided how luxurious or austere should new library buildings be
CISI	systems analysis of a university library final report on a research project the establishment of nine new universities in the 1960s provoked a highly stimulating re examination of the nature purpose and management of academic libraries long established attitudes and methods were questioned but although changes were made the basic difficulty remained   a lack of objective information about the best ways of providing a library service in a university the report of the ugc committee on librarys the parry report 267 which in general endorsed these changes also stressed the need for research into all aspects of academic library provision
CISI	systems approach there is no question that in our age there is a good deal of turmoil about the manner in which our society is run probably at no prior point in the history of man has there been so much discussion about the rights and wrongs of the policy makers whether they be the politicians in albany or sacramento in washington paris or moscow the managers of far flung industrial firms or the people who run educational institutions in all cases the citizen feels a perfect right to have his say about the way in which the managers manage not only has the citizen become far more vocal but he has also in many instances begun to suspect that the people who make the major decisions that affect our lives dont know what they are doing they dont know what they are doing simply because they have no adequate basis to judge the effects of their decisions
CISI	targets for research in library education few librarians and library educators who criticize research relating to their fields realize in 1972 how far research has progressed during the last decade and a half the criticism usually relates to the recognition that librarianship is more of a service and less of a fact  finding field of endeavor and that librarians are primarily trained to assist in the research activities of others rather than to conduct their own one can add here that the average librarian who spends about forty hours a week on his job not always has the stamina to spend his free time on original research or the writing of proposals which either are not adequately funded or are not published with the prominence hoped for if the librarian researcher commits his findings to writing he is occasionally criticized for writing poorly or for having dwelled on topics of limited interest to the reviewer or he finds that while many praise his work there are no funds possibilities or opportunities to translate his conclusions into action
CISI	technical libraries users and their demands a classification of user groups and user demands in technical libraries this study of the habits of customers of technical libraries and information departments had three main aims 1 determination of user demands to discover what items of information or documents customers seek why they seek them and how they obtain them 2 classification of user groups and their demands to test a hypothesis that it is possible to classify customers into meaningful user groups possessing recognizable common features and characteristic behavior patterns and to classify group needs 3 estimation of the significance of the above for librarians to measure the demand on librarians and libraries in terms of expenditure of their time and skill and use of stock made by different user groups
CISI	techniques of information retrieval information retrieval is now an accepted part of the new discipline of information science and technology and its principles are taught not only in librarianship and documentation but also in courses of systems design there are half a dozen useful texts available each with a special emphasis arising from the varied backgrounds and interests of the authors
CISI	technology economic growth and public policy this book explores the relations among research development innovation and economic growth considers the manner in which the economy adapts to technical change and the problems encountered in the processes of adaption and recommends several policy changes designed to encourage technological change consistent with other public policy objectives since they address policy makers as well as scholars the authors have tried to avoid scholarly jargon without sacrificing scholarly rigor
CISI	technology information and organization information transfer in industrial r and d this is an empirical study of information transfer in the r d operations of large industrial corporations its basis is a body of survey data collected from 2000 engineers and scientists in 13 establishments of four corporations and from 1200 members of the institute of electrical and electronics engineers the data describe instances in which respondents acquired useful technical information from sources outside their immediate circle of colleagues the analysis is descriptive in character following a functional approach in which the use of various means of information transfer is considered in relation to the purposes of technical work while the data in general confirm the results of other studies of this sort they demonstrate also that the relative use of alternative means will vary significantly with the circumstances of their use the report explores the association of variations in a number of specific personal organizational and technological factors with variations in the use of sources of information in a more general interpretation of these findings those variations are related to aspects of the goals of the work to which the information was applied the purposes of technical work are considered along two basic dimensions one relating to the potential for contribution to the development of some body of systematic knowledge the other to the support of particular operational objectives when the focus of work is on operational goals local and informal sources account for most instances of information transfer formal and more distant sources are the most common means used when the focus is on professional goals i e those concerned with contributions to knowledge in conclusion the report discusses the effects which management may have within an organization on the process of information transfer and the need for managers and students of the process to take into account the interplay in this process of personal values task requisites and the structure of formal and social groups firms need to establish two way communication about needs and possibilities by so doing they may enhance the effectiveness with which advances in knowledge are translated into innovations in technology meeting the needs of society
CISI	technology and information transfer in 1963 research at the harvard business school was initiated by richard rosenbloom and frank wolek to describe the process by which technical information is communicated and used national and corporate attention had been increasingly drawn to the interaction between scientific and technological advance and social change this problem was considered to be of considerable practical importance at that time as it still is this volume is a product of that effort the research focuses upon the flow of technical information across organizational lines in the research and development operations of large industrial corporations the basis of the work is a body of survey data collected from 2 000 engineers and scientists in 13 establishments of 4 corporations and from 1 200 members of the institute of electrical and electronics engineers the data describe instances in which respondents acquired useful technical information from sources outside their immediate circle of colleagues the analysis is descriptive in character following a functional approach in which the use of various means of information transfer is considered in relation to the purposes of technical work
CISI	text machine and man this work describes a native soviet experiment in creating machine translation and the automatic annotation of texts in foreign languages also generalizes the theoretical results of research in the area of probabilistic text processing within the system man machineman
CISI	telefacsimile in libraries the use of telefacsimile systems to provide rapid transfer of information has great appeal because of a growing interest in the possible applicability of this technology to libraries the council on library resources provided a grant to the institute of library research to conduct an experiment using telefacsimile equipment in a working library situation the study was designed to explore the feasibility of telefacsimile for present interlibrary use it provides information on the performance cost and utility of telefacsimile systems for libraries
CISI	probability theory this book is a textbook intended for those generally familiar with mathematics who are interested in the technical applications of probability theory in particular of the theory of shooting the book will also be of interest to engineers in other fields who find it necessary to use the theory of probability the book is distinguished by the major attention it pays to new branches of probability theory which are important in application for example the theory of probabilistic processes information theory the theory of mass servicing etc
CISI	terminology of documentation the terminology of documentation is intended to help standardize basic terminology in the rapidly developing field of documentation and thus to foster international co operation it should also be useful as a reference work for organizations and individuals working in the fields of documentation libraries and information processing to translators and to students in these fields
CISI	thesaurus construction before work can begin on the construction of a thesaurus a study should be made of the information retrieval system it is intended to serve only when the requirements of the system are known can consideration be given to the type of thesaurus which would be most effective in a specific situation
CISI	the thesaurus in retrieval this book does not purport to provide all the answers to the problem such a claim would be rightly suspect but to collect together problems and experiences pertaining to the technique though three of the case studies in chapter 8 are from outside the united kingdom there is an inevitable bias towards british experience and english language thesauri it is hoped that people outside this country will find the book useful but there is little mention of for example the language problem the way in which compound terms are treated clearly depends on whether one is indexing in german french or english and each language exhibits a different morphology
CISI	computer based selective dissemination of information sdi service for faculty using library of congress machine readable catalog marc records from november 1966 through june 1968 the library of congress conducted a pilot project involving the weekly distribution of its traditional 3x5 catalog cards in machine readable form the marc records provided a search data base for an experiment in current awareness service designed to furnish faculty with biweekly lists of bibliographic notices of new monographs in their specified fields of interest of the 298 social sciences faculty members queried about their interest in participating 209 70 percent responded affirmatively only 40 participants could be accommodated so they were chosen in proportion to the number of faculty members in each department or school anthropology l business 10 economics 3 education 15 government 4 history 4 and sociology 3 an interest statement from each faculty member was translated into both library of congress classification numbers e g e6ll and subject heading terms i e elements of discrete heading separated by a comma dash parenthesis or period e g u s   hist   civil war  prisoners exchange of becomes six terms u s hist civil war prisoners exchange of the resulting interest profiles were recorded on punched cards for computer matching with subject headings and class numbers the weighted term search strategy was used in comparing profiles with marc records each profile was assigned a cutoff weight or hit level of 6 subject heading terms were assigned positive or negative weights so that the sum of weights on matching terms would be equal to exceed or be less than the hit level thereby appropriately causing or preventing the selection of a particular record all class numbers were assigned a weight of 6 so that a hit would occur on any matching number three computer programs were employed in producing the sdi lists program extract used marc master tapes as input and extracted the card number accession number subject heading terms and class number for current records program retrieve compared these terms and class numbers with those in the profiles and recorded the card numbers for hits program print compared these card numbers with those on complete marc records and printed three copies of each record to be sent to the faculty one copy was for the faculty members own use one was to be evaluated and returned and one was to be used for making recommendations to the library subject headings proved to be more effective in searching the marc file mainly because multiple subject headings may be assigned to each record whereas there is only one class number and a hit often occurred on a records second or third heading the sdi system performed well in selecting performed well in selecting relevant records and overall evaluations were highly favorable some 73 percent of notices received by faculty members were for works judged new to the faculty the majority felt that the sdi service provided an automatic regular notification of new works they felt that it usually brought works to their attention quicker than other sources it informed them of items they otherwise would have missed it furnished a compact source listing books in all but only their fields it required very little time and it provided a convenient means for making library recommendations and therefore increased the amount of recommending done all faculty expressed a desire to have sdi service continued
CISI	synthesis identification and control of distributed parameter systems many synthesis identification and control problems that arise in distributed parameter systems are studied two major approaches viz the frequency domain approach and the time domain approach are considered the techniques developed overcome many difficulties that are associated with optimization problems in distributed parameter systems in the frequency domain distributed systems described by the general linear telegraphers equations are considered over a finite band of frequencies an electric network equivalent to these systems is developed many optimization problems that are of practical interest are formulated in terms of this new equivalent network some of the basic principles of lumped network theory are applied to formulate these optimization problems many advantages in the method of solution due to this formulation are discussed in the time domain a method of characteristics is developed as a method of solution for optimization problems first and second order hyperbolic systems are considered imbedding and gradient techniques developed along the characteristics are shown to have numerous computational advantages it is shown that solving for greens function and associated eigenvalue problem is not required it is hoped that the methods developed here will lead efficiently to actual realization of optimal distributed systems
CISI	least cost decision rules for the selection of library materials for compact storage for the last several decades library collections have been growing at exponential rates with no relief evident in the future to help ease the growing financial burden of housing their collections many librarians have suggested employment compact storage depositories for little used materials two aspects to be considered in designing a storage system are the fraction of the collection which is to be stored and the criteria to be used for selecting materials for storage this study demonstrates that for a given selection criterion least cost storage quantities can be assessed by balancing the large circulation costs and the small shelving costs associated with stored materials two storage criteria one based upon the age of the materials and the other utilizing the individual book usage rates are discussed and compared for the age policy the objective is the determination of a least cost critical age at which materials are transferred to storage and which defines the fraction of the collection that should be stored the model assumes that the circulation rate of the books decline with age according to an average geometric pattern of obsolescence the average time gap between the most recent circulations of books is utilized as the measure for rate of usage of a book the storage decision variable resulting from the minimization of the total cost function of the usage rate policy is a critical intercirculation gap the maximum amount of time that a book should be permitted to remain in a working collection without being used those books which are stored by the above rule might be those for which the time since last use exceeds the critical intercirculation gap hence although the least cost selection rule is independent of the composite distribution of usage rates the fraction of the collection stored depends upon the circulation activities of the individual libraries an empirical evaluation of the storage models was made using data collected from three libraries at purdue university and estimates of cost parameters extracted from the literature calculations for the least cost decision rules and the related costs demonstrate that significant savings can be realized from storage of materials but the calculations indicate that a large portion of the collection must be stored comparisons of the age policy and the usage rate policy indicate that the latter criterion is preferred for all cases examined including a situation where the usage rate policy is handicapped with a relatively high unit relocation cost sensitivity analyses of the cost parameters for practical ranges of values show that the choice for the length of the planning horizon has a relatively insignificant effect on the decision rules that changes in the capacity related cost parameters will cause significant changes in the results and that the rules are extremely sensitive to changes in the circulation cost differential an important component of the latter consideration is a rather subjective estimate for the cost of a service delay which appears to have a potentially large influence on the decision rules
CISI	journal usage patterns and their implications in the planning of library systems access to the literature is an essential requirement for advanced research libraries particularly academic libraries have traditionally borne the major responsibility for providing public access to the worlds literature most universities have developed rather complex multilibrary systems of specialized libraries in order to meet the needs of various groups which they serve this use of special libraries to meet the needs of particular groups has generally resulted in a somewhat arbitrary division of the literature by disciplines the purpose of this study is to investigate some of the effects that this division of the literature has on its accessibility and in particular to examine the disciplines the interdisciplinary relationships and the scattering characteristics as they are revealed by journal usage patterns these results are applied to the problem of planning and design of library systems measures of journal productivity are proposed and means of actually estimating these measures based on citations usage and abstract data are developed each of these means of estimating journal productivity has its advantages and limitations since these value measures are usually made relative to a particular discipline many problems arise unless disciplines can be defined in comparable terms a discipline wheel is proposed which can serve as a conceptual framework in which to view the different disciplines this framework provides a basis for measuring the breadth of a discipline and also for measuring the similarity between two disciplines one of the more important characteristics which has emerged from the study of journal productivity is the concept of scattering of articles or title dispersion a powerful tool for describing this phenomenon which has resulted from earlier studies is the bradford distribution the bradford distribution is fitted to over fifty groups of productivity data from various sources with mixed results other possible distributions particularly the yule borel and the fisher distributions are also considered the applications of productivity functions in the operation design and evaluation of library systems are virtually unlimited their use in determining the size of a collection finding the marginal value of adding additional journals to a collection determining user convenience and building mathematical models of library systems are among some of the applications which are considered it is also possible based on productivity functions to predict the comprehensiveness of a particular library system as a function of the number of subscriptions it receives the purdue university libraries provided an actual library system to which the above concepts could be applied a large set of citation data was collected this data consisted of 24 953 citations from 752 ph d dissertations written in technical fields at purdue university complete records of the universitys scientific journal holdings were also obtained the bradford distribution is fitted to the citation data with generally satisfactory results the similarity between the different scientific disciplines is measured as is the similarity between the different libraries the breadth of the disciplines is also measured differences between the journal usage patterns and the systems holdings are examined alternate library system configurations are proposed and evaluated through the use of comprehensiveness functions this study shows that it is possible to quantitatively measure such concepts as title dispersion breadth of a discipline the similarity between disciplines and others the quantification of these concepts leads to a basis for the design and evaluation of complete library systems
CISI	utility of automatic classification systems for information storage and retrieval large scale on line information storage and retrieval systems pose numerous problems above those encountered by smaller systems the more critical of these problems involve degree of automation flexibility browsability storage space and retrieval time a step toward the solution of these problems is presented here along with several demonstrations of feasibility and advantages the methodology on which this solution is based is that of a posteriori automatic classification of the document collection feasibility is demonstrated by automatically classifying a file of 50 000 document descriptions the advantages of automatic classification are demonstrated by establishing methods for measuring the quality of classification systems and applying these measures to a number of different classification strategies by indexing the 50 000 documents by two independent methods one manual and one automatic it is shown that these advantages are not dependent upon the indexing method used it was found that among those automatic classification algorithms studied one particular algorithm clasfy consistently outperformed the others in addition it was found that this algorithm produced classifications at least as good with respect to the measured established in this dissertation as the a priori manual classification system currently in use with the aforementioned file the actual classification schedules produced by clasfy in classifying a file of almost 50 000 document descriptions into 265 categories are included as an appendix to this dissertation
CISI	time lag in cataloging any who have the arduous task of assisting a student through that ultimate of academic exercises the preparation and defense of a dissertation are likely to define happiness as a good book written by an advisee this book is a cause of joy the author expended much more effort than is usually the case to gain even the smallest detail because the subject matter is strangely intractable hedged round with perplexities and not a few vested interests letters and reports get locked away where they may not be seen except by the most persistent investigator and one who somehow meets criteria that no one else can claim in the end the author deserves the praise and the advisor is well rewarded with the inner satisfaction that comes from participation in an important investigation finished as an influential and well written book
CISI	title derivative indexing techniques a comparative study the increasing volume of published literature continues to present problems in relation to information handling and information representation as the magnitude and complexity of the available information has continued to increase investigators have examined means of reducing the costly and time consuming processes involved when human beings assign index terms to documents recognition of the general inadequacy of present indexing and concern over time and cost factors in index preparation have prompted experimentation in the development and application of machines to assist in the indexing process as a result use of suitable mechanized or partly mechanized procedures to replace or complement the manual indexing process has become more widespread machine indexing is a process whereby mechanized or automatic selection or generation of indexing terms is accomplished the present study investigates one aspect of automatic computer based indexing the permuted title index
CISI	towards information retrieval the selection of papers published here explores activities in which indefinite neglect of either aspect the conceptual or the mechanical will lead to practical and theoretical disaster they centre on the recovery of records according to their subject matter since libraries began librarians have evolved studied and taught procedures for indexing and classifying these allow some delegation from subject specialists who understand the subject matter to library staff who can recognize the ways in which specialists talk about it the procedures consider mostly only the interpretation of texts not the text itself as an object with recognizable marks subject to the laws of physics and the principles of engineering they assume the problems of topic identification solved and the methods for recovering physical texts as independent of the methods for describing the interpretations of texts
CISI	training for library service a report prepared for the carnegie corporation of new york the primary purpose in preparing the following report was to present existing conditions in this country with respect to training for library work in such a way that the educator and the layman interested in educational problems might be able to form a true conception of the steps that should be taken to improve this phase of the library situation the author has been obliged to limit the scope of his study to the so called professional schools he has treated only incidentally training classes summer schools and other types of library training agency an effort has been made to discover and to point out the strong and weak points in the organization of these library schools and in the training which they offer many of the defects disclosed could be remedied by the schools themselves others are due to extreme poverty and can be remedied only by increased income
CISI	university library administration a university library is both a collegiate library and a research library it is collegiate in its provision of books and other documentary records to support the students program of instruction and to encourage the habit of reading and the use of libraries as does the college library the university library must also provide materials for use by the faculty members in the preparation of their courses of instruction and by the staff of the institution in the performance of their administrative responsibilities however the university library differs from the college library in offering a wider range of undergraduate programs offering graduate instruction beyond the masters level and usually offering advanced professional programs in a number of fields
CISI	undergraduate library the development of the separately housed undergraduate library on the modern university campus is a recent innovation   so recent in fact that in september 1965 there were only six such libraries in the united states the interest in effective undergraduate education which led to the creation of these libraries however is not of such recent origin as early as 1608 when thomas james was appointed to bodleys library he proposed the establishment of an undergraduate library to help the younger student but sir thomas bodley was opposed so it is to harvard that we turn for an example of the protracted concern for the undergraduates plight despite the concern voiced by these earlier writers most universities and their libraries were relatively small until this century more important they were largely undergraduate institutions the great expansion of graduate education is a twentieth century phenomenon the problems of the undergraduate in using university collections were greatly compounded by the striking growth in the size of collections and by an increasing emphasis on the acquisition of materials suitable for research the large university collections became increasingly difficult for the undergraduate to use when he had to select his books from the card catalog and obtain them through paging in a closed stack system he might well abandon the attempt before finally locating a book which was not checked out missing or at the bindery   and which was suitable for his purposes the university library was also difficult to use because it was crowded   study conditions were unsatisfactory and staff was insufficient to handle the volume of work
CISI	understanding media the extensions of man with the advent of individual detribalized man a new education was needed plato devised such a new program for literate men it was based on the ideas with the phonetic alphabet classified wisdom took over from the operational wisdom of homer and hesiod and the tribal encyclopedia education by classified data has been the western program ever since now however in the electronic age data classification yields to pattern recognition the key phrase at ibm when data moves instantly classification is too fragmentary in order to cope with data at electric speed in typical situations of information overload men resort to the study of configurations like the sailor in edgar allan poes maelstrom the medium is the message means in terms of the electronic age that a totally new environment has been created the content of this new environment is the old mechanized environment of the industrial age
CISI	understanding media the extensions of man when it was decided that cognitive psychology would not specify size limits for articles and that we would publish relevant papers in artificial intelligence we hardly anticipated devoting an entire issue to a single piece of work however winograds program for understanding natural language seems sufficiently general and important in its implications to warrant the experiment some readers will find sufficient the first two sections which present respectively an overview of the system and what it does and a first rate evaluation of research in artificial intelligence on natural language processing semantics and theorem proving others will want to explore in detail the structure of the syntactic component the treatment of semantics and the programming language for specifying theories of problem solving each of these contributions is significant in its own right together they form a unique integrated system capable of parsing interpreting and acting upon the information contained in complex natural language discourse
CISI	understanding scientific literatures a bibliographic approach as the author states the methods he describes treat the growth of a scientific literature as a social phenomenon in its own right not as a material byproduct of the knowledge and concepts of the science written about management of the literature of physics say does not first demand the study of physics but of physicists management of the literature of information sciences demands first the study of information scientists
CISI	the universal decimal classification purpose of this paper the purpose of this preliminary study is to attempt to discover how far it succeeds at present and how far and by what methods it may continue to succeed or be made to succeed in the future one person or two for brian vickery is tackling the problem from the point of view of scientific and technological users with however many helpful consultants can only hope to isolate some of the problems and to indicate some of the possible solutions this it is hoped may prepare the ground and stimulate the critical and creative efforts of others towards fruitful developments
CISI	the universal decimal classification and technical information indexing this study of the udc sets out from the assumption that both general and special documentation services can make use of a general classification on the other hand it assumes that the criticisms of the udc   the preference of some documentalists for alternative special schemes   imply that the udc does not adequately provide the facilities currently needed in examining these criticisms and some special schemes an effort is made here to elucidate those features of the udc which prevent it from being more widely used and then to suggest how the udc might be developed to provide the facilities needed
CISI	the intermediate lexicon a new step towards international co operation in scientific and technical information the agencies specializing in documentation of documentation i e handling the literature on scientific and technical information are in turn having problems with the growth of information the number of their centres has been growing during the last few years   often several in a country and all with activities that are often very similar scanning and abstracting of documents from the same sources indexing jobs that may differ only in practical details more or less identical end products descriptive bibliographies abstracting bulletins indexes selective distribution programmes card indexes and so on
CISI	the ranking of biomedical periodicals from the indian scientists point of view the output of scientific literature has been increasing exponentially since the second quarter of this century new journals in specialized branches of science keep appearing and established periodicals either multiply the number of volumes per year or split into different titles covering narrower subject areas in order to cope with the flow of communications received for publication the limited resources or libraries particularly in the developing countries do not permit them to increase library space or budget at a rate commensurate with this rise in publication consequently research libraries in such countries as india must be highly selective in their acquisition programmes and to do so without detriment to the research interests of the institution they serve they urgently need dependable data on the ranking of periodicals according to the particular research needs of their respective countries in this article an attempt is made to rank periodicals in the field of the biomedical sciences from the point of view of the indian scientist this method may also be followed in the libraries of other developing countries by changing the citing journals according to their countrys needs
CISI	universal bibliographical control ubc the author outlines a plan for the systematic handling of bibliographical data from the time a book is printed anywhere in the world until its cataloguing in the libraries the various problems are set forth and possible solutions proposed
CISI	cataloguing in publication a new programme of pre publication cataloguing in the united states of america with comments on some similar programmes the cataloguing in source experiment carried out by the united states library of congress ended in 1959 studies on the feasibility of a new pre publication cataloguing programme were undertaken and on 1 july 1971 a new cataloguing in publication programmes were started other programmes for pre publication cataloguing namely in brazil and the union of soviet socialist republics are described
CISI	international standardization of cataloguing and bibliographical records the work of the ifla committee on cataloguing the ilfa committee on cataloguing has been at work since 1954 to establish international standards for cataloguing and bibliographical records and was responsible for the international conference on cataloguing principles paris 1961 and the international medical of cataloguing experts copenhagen 1969 a new impetus to its work has been given in 1971 with the establishment of its permanent cataoguing secretariat whose function were to act as a co ordinating centre to promote cataloguing projects and to disseminate information
CISI	isds and the functions and activities of national centres an international serials data system isds is being established within the framework of unisist   a world science information system each serial will be assigned an international standard serial number issn an international centre for the registration of serial publications with headquarters in paris will be responsible for specifying the characteristics of the world register and maintaining an up to date file of serial titles national and regional centres will supply input on new titles to the register and act as a link between the international centre and individual users
CISI	natis the theme for the 1970s in this article stephen green a member of the british delegation to the intergovernmental conference on the planning of national documentation library and archives infrastructures gives his views on the results of the conference and its implications for the future development of national information systems natis in member states
CISI	an unhurried view of copyright copyright protection became necessary with the invention of the printing press and had its early beginnings in the british censorship laws the fortunes of the law of copyright have always been closely connected with freedom of expression on the one hand and with technological improvements in means of dissemination on the other successive ages have drawn different balances among the interest of the writer in the control and exploitation of his intellectual property the related interest of the publisher and the competing interest of society in the untrammeled dissemination of ideas it is this striking of balances in the law of copyright in the past at present and for the future which constitutes the central theme of the james carpentier lectures delivered by professor benjamin kaplan at the columbia university school of law in march 1966
CISI	union library catalogs in the united states this volume on union library catalogs in the united states presents the results of a nationwide survey of all aspects of union cataloging by a group of investigators who have been engaged with the task for more than a year the aim is to cover the history current status and future prospects of various types of union catalogs for american libraries
CISI	book availability and the library user the essentially logistical problem of making library books physically available when wanted by library users is central to librarianship this book is a tentative attempt to provide a treatise on this problem as such it has to deal with both theoretical analysis and the practicality of solutions no apology is made for the attention devoted to theoretical analysis because the author believes that a clear conceptual understanding of the factors involved is important for improved librarianship the fact that analytical models are not always usable does not mean that the insight that can sometimes be derived from such analyses will not lead to a better understanding of the problems and thereby to improved library services
CISI	universal bibliographic control ifla will be nearly fifty years old when dorothy andersons ubc paper is published it is tempting to say that it is a half a century overdue when librarians first began to look beyond their national borders bibliographic control was in the forefront of their concern gradually however these pioneers of international librarianship began to realize that technical problems were too ambitious for multilateral action and in their discussions the emphasis was placed more on functions and organizations on the social and even economic achievements of the international library community   which was not fully international at all   were limited to comparisons of national efforts with some countries constantly over critical and others overgenerous outstanding bibliographic projects like the gesamtkatalog der wiegendrucke were international in scope but national in conception
CISI	the universal decimal classification this study represents the result of some fifteen years of contact with the universal decimal classification as a user as a reviser and as a classification teacher as a information officer at the atomic energy research establishment harwell i was concerned with the use of the universal decimal classification udc both as classifier and as user of the resulting catalogues i was also directly concerned as liaison officer for the atomic energy research committee for udc with the development of the code of practice which later became the basis of the special subject edition for nuclear science and engineering with accelerators this work was carried out along the general lines indicated in this study and is now part of udc which indicates that modern ideas can be accommodated within the scheme without undue strain
CISI	universals in linguistic theory we feel that a profound change has occurred in linguistic thinking in the last decade it is not longer of any interest to describe one after another language anyhow without regard to the relevance of the facts to general linguistic theory as ross put it it makes no sense to talk about describing a language in terms of its own structure alone  toward the end of the conference when it had become apparent that the general agreement did not encompass any currently explicitly formulated model the question was raised what should we be teaching our students langendoens answer seems to us most apt we should give them the ability to recognize a interesting linguistic problem when they see one that is one which throws some light   negative or positive   on our conceptions of what languages in general are like
CISI	the case of citation data in writing the history of science can a computer write the history of science probably not in the sense usually implied however the research reported herein is a preliminary attempt to understand and define some basic problems that must be solved if computers are ever to aid the historian of science   no less supplant him in this study it was necessary to select a recent important scientific breakthrough which was based on the cumulation of years of diverse scientific achievement for this reason we selected the discovery of the dna code for a concise historical description of the events we then selected the genetic code a book by dr isaac asimov which describes the major scientific developments that eventually led to the duplication in the laboratory of the process of protein synthesis under control of dna
CISI	user requirements in identifying desired works in large libraries the work reported here is a study of the utilization of the card catalog of a very large library specifically the principal catalog of the library system of yale university the study was motivated by two basic concerns one of them of a long term or exploratory nature the other of a short term or operationally supportive nature the long term concern is the question of how to design a computerized catalog for a very large library that can be expected to give the best possible performance the short term concern is the question of whether and of so how existing card catalogs in very large libraries may be made more responsive to user requirements it was recognized that a carefully designed study of actual utilization of a catalog of a large library could shed useful light in both areas of concern
CISI	distill or drown the need for reviews the information explosion sparks a need for creative synthesis of facts and ideas for efficient access to good scientific literature we must devise new schemes for compression
CISI	information communication knowledge at the british association meeting in exeter last month professor ziman addressed the section devoted to general topics on the question of how scientific information becomes public knowledge the system of communication he implied is not as rotten as some like to think
CISI	vocabulary control for information retrieval this book deals with properties of vocabularies for indexing and searching document collections the construction organization display and maintenance of these vocabularies and the vocabulary as a factor affecting the performance of retrieval systems most of the text is concerned with vocabularies for post  coordinate retrieval systems with special emphasis on thesauri and machine based systems vocabularies for pre coordinate systems e g alphabetical subject catalogs and classified catalogs are discussed only briefly to provide historical perspective and for the light they shed on the problems o vocabulary control in general this type of vocabulary is well covered in existing texts
CISI	the weapons acquisitition process an economic analysis a distinctive feature of american weapons development and production is the use of private firms to carry forward most of the effort this volume is primarily concerned with the government  business relationships within which these activities take place our title reflects our emphasis weapons acquisition is defined to include the conception development and production of technically advanced weapons for ultimate use by the armed forces process emphasizes the flow of decisions and activities during weapons programs including the actions reactions and interactions of government agencies and defense contractors economic analysis indicates our concern with how these activities and relationships affect the quality time cost and value outcomes of weapons programs the principal objective of this volume is increased knowledge of these facets of weapons development and production such an objective classified the volume as a social science rather than administrative study yet most social science research however pure the form is ultimately directed at changing public policy that is the intention here but this book does not conclude with a specific set of public policy recommendations rather it is largely limited to providing understanding   a prerequisite to criticism debate revision and improvement
CISI	weeding library collections this book is based upon two recent research projects in weeding and identifying core collections however it became apparent that the principles and techniques studied are applicable to almost all types of library collections this work has been designed to be used for four distinct purposes 1 as a comprehensive source summarizing the opinion knowledge and serious research in the field of weeding the authors own research is reported in such detail that replication of the studies is possible in addition this book contains the first report of the harrison study 2 as a do it yourself guide for librarians wishing to weed out their present collections it is the aim of this book not only to explain and justify its methods but to include a step by step procedure for weeding without tears 3 as a textbook in library schools especially in courses that deal with the acquisition and maintenance of library collections for weeding is one of the best techniques available for the long range building of useful collections 4 as a stimulus to further study in this entire area it is hoped that libraries using the recommended methods will measure and report upon the costs of weeding and the impact of such weeding upon changes in the amount of circulation and in user satisfaction
CISI	some behavioral patterns of library users the 80 20 rule a characteristic of inventory in business or industry is that approximately 80 percent of the number of transactions taken from a warehouse represents about 20 percent of the items stocked this may also be considered as a ranking of stock items by their transaction activity which will show that the top 20 percent of the stocked items i e the most active items account for about 80 percent of the total number of transactions the rule is sometimes expressed as the 75 25 rule with the same interpretation it is only by coincidence that the figures add to 100 as the phenomena relate to the relationships between the two statistical measures
CISI	the wiswesser line formula chemical notation wln the line formula chemical notation described in this manual is a precise and concise means of expressing the structural formulas of chemical compounds its basic idea is to use letter symbols to denote functional groups and to use numbers to express the lengths of alkyl chains and the sizes of rings these symbols then are cited in connecting order from one end of the molecule to the other for the past hundred years ever since structural chemistry began chemists have been using graphic symbols in this way this line formula notation is simply an extension and standardization of this practice
CISI	women in librarianship there are some who question whether the status of women in the library profession is a major issue a survey of library literature however shows an increase in the factual data available regarding differences between men and women in salaries promotional patterns and other professional situations there are local library groups which are examining the status of women in their own libraries and organizing to improve their employment situations on the state and national level conference programs and workshops at library association meetings have dealt with various aspects of sex discrimination affirmative action policies sexism in childrens materials and the like
CISI	work and motivation the basic plan for this book was evolved during the summer of 1959 at that time i was working on a chapter entitled industrial social psychology for the annual review of psychology i was impressed by the large amount of research being conducted in the field but found the task of integrating that research and of identifying the progress made during the period of the review exceedingly difficult in part this difficulty was a result of the great differences among investigators in the phenomena they selected for study and the methods they used to study it a more troublesome problem however was the apparent theoretical implications of their research concepts tended to be highly specific and inadequately defined there was little standardization of terminology and little consideration for the nature of the processes underlying empirical data
CISI	work and the nature of man work and the nature of man is the third book of a trilogy concerning job attitudes in the first book job attitudes review of research and opinion my colleagues and i attempted to review and systematize what had been gleaned from research and contemplation after a half century of effort in the motivation to work that followed we described an original research study that offered a completely new hypothesis about the way people feel about their jobs in this book i have taken that hypothesis and expanded it to a general theory of work and the nature of man while the trilogy contains the three basic stages of scientific inquiry knowledge of what has gone before new research and finally a theory the task that i set out for myself many years ago upon graduation for the school of public health at the university of pittsburgh is just beginning that task was to give original substance to the new discipline of industrial mental health and if possible to make some positive contributions
CISI	world dynamics over the last several decades interest in economic development population growth and the world environment has expanded rapidly as world wide stresses have increased many individuals and organizations have begun to study and to influence the changing aspects of the world situation but it seems fair to observe that most of the activity has been addressed to separate facets of the world system little has yet been done to show how the many actions and forces are affecting one another to produce the total consequences that we observe now however many persons are coming to believe that the interactions within the whole are more important than the sum of the separate parts this book was undertaken as one step toward showing how the behavior of the world system results from mutual interplay between its demographic industrial and agricultural subsystems
CISI	world trends in library education one of the most significant aspects of the evolution of librarianship in the twentieth century has been the emergence of the library schools as a potent factor in shaping new philosophies and new attitudes in the library profession the intention of the present work is to examine some of the implications of this rapid growth in the number of library schools noting current trends and possible changes in the future inevitably some limitations have had to be imposed and there has been a deliberate concentration upon anglo  american library education while at the same time examining other major patterns of professional education for librarians which exist in the world and comparing these with the approach of the english speaking countries an attempt has been made to trace the influences which the british and america systems of library education have had particularly in the developing countries
CISI	legal restrictions on exploitation of the patent monopoly an economic analysis the patent laws confer on a patentee power to exclude all others from making using or selling his invention in furtherance of a constitutionally recognized goal   to promote the progress of science and the useful arts   congress has thus adopted a constitutionally authorized means   securing to inventors the exclusive right to their respective discoveries the constitutional clause is remarkable in several respects its recognition of the possibility that invention might require encouragement implies not only that technological innovation is desirable but also that but for legal subsidization the quantity of innovation forthcoming would or might be less than optimum this recognition coming on the morn of an era during which the tendency of a free market to achieve optimality in all activities was greatly and religiously overestimated prompts brief inquiry into the soundness of the supposition
CISI	language and thought this book considers the basic aspects of this complex problem   the historical and social essence of language and thought their interaction in historical evolution the essence of linguistic meaning in relation to the content side of thought and the physiological mechanism of the processes of abstraction generalization etc
CISI	modern integral information systems for chemistry and chemical technology at the present time about 15 of all the world publications of scientific and technical literature relate to chemistry and chemical technology each year throughout the world more than 250 000 documents are published journal papers specifications for authors certificates and patents scientific and technical reports monographs etc and in the last twenty years the number of such documents has increased by an average of 9 a year in these scientific documents information on 100 150 thousand new chemical compounds is published
