Wu Weimin

Improvable Deflate Algorithm

The Improvable Deflate Algorithm proposed in this paper has a certain improvement based on the previous Deflate Algorithm. In our algorithm, the first step is to implement LZ77 algorithm, the second step is the dynamic or static Huffman encoding. As LZ77 is to operate the bit of the data and change the original character of the byte, we replace the dynamic or static Huffman encoding with active Markov Chain. Dynamic Markov Chain is united by 2 bits of the binary system whose input can only be 01, 01, 10 or 11, which can simplifies and lowers the risk of memory overflow in the status space due to tThe Improvable Deflate Algorithm proposed in this paper has a certain improvement based on the previous Deflate Algorithm. In our algorithm, the first step is to implement LZ77 algorithm, the second step is the dynamic or static Huffman encoding. As LZ77 is to operate the bit of the data and change the original character of the byte, we replace the dynamic or static Huffman encoding with active Markov Chain. Dynamic Markov Chain is united by 2 bits of the binary system whose input can only be 01, 01, 10 or 11, which can simplifies and lowers the risk of memory overflow in the status space due to the rapid increase of the data.he rapid increase of the data.

Technique of source code obfuscation based on data flow and control flow tansformations

This paper mainly present a solution to cross platform problem about the obfuscation in C/C++ source code, and describe the principle and performance of source code obfuscation algorithm, such as layout obfuscation, data flow obfuscation and control structure flow obfuscation. And it analysiss the obfuscation algorithms performance of the strength, flexibility, and cost by experimentation. Finally, it discusses the prospect of the research and application of the source code obfuscation technology.

Array modeling in Java virtual machine

Array is an important feature in Java and Java Virtual Machine. In spite of its importance, it has not been modeled by any existing Java Virtual Machine Models. In this paper, we define an extending model which uses an existing model as a basis and give the hierarchy of these two models, to model the array. In the extending model, we model the array in three steps. The first step is adding array related instructions in a formal way. The second step is refining the type compatibility to include array types. The last step is implementing array loading process also in a formal way. In the last part of thesis, we give the future work of extending other important features in Java and Java Virtual Machine.