Based on the answers provided, the model should make the following corrections to the 3D object:

1. Ensure that the height of the cylinder is twice its diameter. This can be achieved by adjusting the height or diameter of the cylinder until the ratio is 2:1.

2. Make sure that exactly 1/3rd of the material has been removed from the cylinder. This can be done by adjusting the angle or depth of the cut until the remaining volume of the cylinder is 2/3rds of the original volume.