Xiangde Zhang

A Novel Image Encryption Scheme Using the Composite Discrete Chaotic System

The composite discrete chaotic system (CDCS) is a complex chaotic system that combines two or more discrete chaotic systems. This system holds the chaotic characteristics of different chaotic systems in a random way and has more complex chaotic behaviors. In this paper, we aim to provide a novel image encryption algorithm based on a new two-dimensional (2D) CDCS. The proposed scheme consists of two parts: firstly, we propose a new 2D CDCS and analysis the chaotic behaviors, then, we introduce the bit-level permutation and pixel-level diffusion encryption architecture with the new CDCS to form the full proposed algorithm. Random values and the total information of the plain image are added into the diffusion procedure to enhance the security of the proposed algorithm. Both the theoretical analysis and simulations confirm the security of the proposed algorithm.

Alignment free comparison: Similarity distribution between the DNA primary sequences based on the shortest absent word

This work proposes an alignment free comparison model for the DNA primary sequences. In this paper, we treat the double strands of the DNA rather than single strand. We define the shortest absent word of the double strands between the DNA sequences and some properties are studied to speed up the algorithm for searching the shortest absent word. We present a novel model for comparison, in which the similarity distribution is introduced to describe the similarity between the sequences. A distance measure is deduced based on the Shannon entropy meanwhile is used in phylogenetic analysis. Some experiments show that our model performs well in the field of sequence analysis.

A novel iris and chaos-based random number generator

A novel kind of iris and chaotic-based random number generator (ICRNG) is developed from the unique randomness and unpredictability of iris. This method combines biometric feature extraction and random number generation in a novel way. Firstly, we get the non-deterministic source-iris image by iris acquisition equipment, then, we use chaotic function to eliminate the similar pattern in iris from the same person and get the unpredictable random sequence. We use auto-correlation function method and correlation coefficients method to show that ICRNG is linearly independent, then, we use BDS statistical test method to verify ICRNG is nonlinearly independent. Finally, the randomness of ICRNG is verified by histogram analysis, information analysis, sensitivity analysis, FIPS 140-2 tests and NIST SP 800-22 tests. Hence, ICRNG possess satisfactory performance and can be implemented on common PC platform.

Alignment free comparison: k word voting model and its applications

Alignment free sequence comparison is widely used in sequence analysis, especially in computational biology for large scale similarity comparison. In this paper, we propose a word voting model to compare the biological sequences without alignment. Unlike many comparison methods based on the k word, this model does not use the k word frequency or statistics. Thus there is no limitation on the choice of k. Instead, we used information entropy of gamma distribution to characterize the differences among biological sequences in this model. Finally, we employed the model to do the similarity search and phylogenetic tree construction to further validate the model.

An estimator for local analysis of genome based on the minimal absent word.

This study presents an alternative alignment-free relative feature analysis method based on the minimal absent word, which has potential advantages over the local alignment method in local analysis. Smooth-local-analysis-curve and similarity-distribution are constructed for a fast, efficient, and visual comparison. Moreover, when the multi-sequence-comparison is needed, the local-analysis-curves can illustrate some interesting zones.

Weierstrass Function-based Uniform Random Number Generator

The effect of

Noncoding Variants Functional Prioritization Methods Based on Predicted Regulatory Factor Binding Sites

a, b, x

An RNA secondary structure prediction method based on minimum and suboptimal free energy structures.

to the randomness of Weierstrass function:

An image encryption scheme using generalized Arnold map and affine cipher

\sum_{n=0}^\infty a^n\cos(b^n\pi x)

An image encryption algorithm based on compound homogeneous hyper-chaotic system

is studied, then, a new Weierstrass Function-based random number generator (WFU-RNG) is designed, the random numbers uniformly distribute over the interval