The least square method used for velocity ambiguity resolution is derived,and a novel method which is called the invariant imbedding method to resolve velocity ambiguity is proposed.

The influence of rubber membrane penetration on volume change in large-scale triaxial tests of granular materials along stress paths with variational confining pressure need to be eliminated.

A time space field based algorithm is proposed, which introduces the array encode to improve the embedding efficiency, hide the information into the least significant three bit planes to extend the embedding capacity, pick the pixel whose grey value greater than certain valve value as cover pixel to prevent the image to lose the nature looking.

With the main purpose of improving the embedding capacity and concealment,using Human Auditory System (HAS) masking properties,an audio steganography algorithm based on lifting wavelet transform and matrix coding to embed secret information was proposed.