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Fast parallel algorithms for discrete Gabor expansion and transform based on multirate filtering

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Science china(information Sciences) 2012年第2期55卷 293-300页

作者： TAO Liang1 & GU JuanJuan2 1School of Computer Science and Technology,Anhui University,Hefei 230039,china 2department of Electronic information and Electrical Engineering,Hefei University,Hefei 230022,china 1. School of Computer Science and Technology Anhui University Hefei 230039 China2. Department of Electronic Information and Electrical Engineering Hefei University Hefei 230022 China

The Gabor transform has long been recognized as a very useful tool for the joint time and frequency analysis in signal *** real time applications,however,were limited due to the high computational complexity of the Gabor transform *** this paper,some novel and fast parallel algorithms for the finite discrete Gabor expansion and transform are presented based on multirate *** analysis filter bank is designed for the finite discrete Gabor transform(DGT)and a synthesis filter bank is designed for the finite discrete Gabor expansion(DGE).Each of the parallel channels in the two filter banks has a unified structure and can apply the FFT and the IFFT to reduce its computational *** computational complexity of each parallel channel does not change as the oversampling rate *** fact,it is very low and depends only on the length of the input discrete signal and the number of the Gabor frequency sampling *** computational complexity of the proposed parallel algorithms is analyzed and compared with that of the major existing parallel algorithms for the finite DGT and *** results indicate that the proposed parallel algorithms for the finite DGT and DGE based on multirate filtering are very attractive for real time signal processing.

关键词： discrete Gabor expansion discrete Gabor transform critical sampling and oversampling multirate filtering analysis and synthesis filter banks

Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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Science china(information Sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2 & FENG GuangZeng3 1department of Electronic and information Engineering, Zhejiang Institute of Media and Communications, Hangzhou 310018, china 2department of information Engineering, Jiangsu City Vocation College, Nanjing 210036, china 3College of Communication and information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, china 1. department of Electronic and information Engineering Zhejiang Institute of Media and Communications Hangzhou 310018 China2. Department of Information Engineering Jiangsu City Vocation College Nanjing 210036 China3. College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

On the least primitive root in number fields

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Science china Mathematics 2010年第9期53卷 2489-2500页

作者： WANG TianZe1,& GONG Ke21School of Mathematics and information Sciences,North china University of Water Resources and Electric Power,Zhengzhou 450011,china 2department of Mathematics,Henan University,Kaifeng 475004,china 1. School of Mathematics and information Sciences North China University of Water Resources and Electric Power Zhengzhou 450011 China2. Department of Mathematics Henan University Kaifeng 475004 China

Let K be an algebraic number field and OK its ring of *** any prime ideal p,the group(OK/p) of the reduced residue classes of integers is *** call any element of a generator of the group(OK/p) a primitive root modulo *** both by Shoup's bound for the rational improvement and Wang and Bauer's generalization of the conditional result of Wang Yuan in 1959,we give in this paper a new bound for the least primitive root modulo a prime ideal p under the Grand Riemann Hypothesis for algebraic number *** results can be viewed as either the improvement of the result of Wang and Bauer or the generalization of the result of Shoup.

关键词： primitive root algebraic number fields Hecke zeta function

About the convergence rates of a class of gene expression programming

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Science china(information Sciences) 2010年第4期53卷 715-728页

作者： DU Xin1,2* & DING LiXin1 1State Key Laboratory of Software Engineering, Wuhan University, Wuhan 430072, china 2department of information Engineering, Shijiazhuang University of Economics, Shijiazhuang 050031, china 1. State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China2. Department of Information Engineering Shijiazhuang University of Economics Shijiazhuang 050031 China

This paper studies the convergence rates of gene expression programming based on maintaining elitist (ME-GEP) by means of Markov chain and spectrum analysis. We obtain the following results: (1) ME-GEP algorithm converges to the global optimum in probability. (2) The convergence rates of ME-GEP algorithm depend on the revised spectral radius of transition matrix of Markov chain corresponding to the algorithm. (3) The upper bounds of revised spectral radius are estimated, which are determined by the parameters of ME-GEP algorithm. (4) As an application of the theoretical results acquired in the paper, the convergence rates of ME-GEP for the polynomial function modeling problem are also analyzed, which verifies the relations between the convergence rates and the algorithm parameters.

关键词： GEP ME-GEP convergence rates Markov chain revised spectral radius

Image universal steganalysis based on best wavelet packet decomposition

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Science china(information Sciences) 2010年第3期53卷 634-647页

作者： LUO XiangYang1,2, LIU FenLin1, YANG ChunFang1 & WANG DaoShun2 1information Science and Technology Institute, Zhengzhou 450002, china 2department of Computer Science and Technology, Tsinghua University, Beijing 100084, china 1. information Science and Technology Institute Zhengzhou 450002 China2. Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Based on the best wavelet packet decomposition of images, a new universal steganalysis method with high detection correct ratio is proposed. First, the best wavelet packet decomposition of image based on the Shannon entropy information cost function is made. Second, high order absolute characteristic function moments of histogram extracted from the coefficient subbands obtained by best wavelet packet decomposition are regarded as features. Finally, these features are processed and a back-propagation (BP) neural network is designed to classify original and stego images. Three different steganalysis algorithms for three different cases of background and application condition are presented. To validate the performance of the proposed method, a series of experiments are made for six kinds of typical steganography methods, i.e. LSB, LTSB, PMK, Jsteg, F5 and JPHide. Results show that, the average detection accuracy of the proposed method exceeds at least 6.4% and up to 15.4% and has a better universal performance than its closest competitors. Furthermore, the proposed method can provide reference for designing the pattern recognition and classification algorithm based on best wavelet packet decomposition.

关键词： steganography digital images universal steganalysis best wavelet packet decomposition BP neural network

A relationship between the nonexistence of generalized bent functions and class groups

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Science china Mathematics 2010年第1期53卷 213-222页

作者： LIU FengMei 1,& YUE Qin 21 department of information Research,College of information Engineering,information Engineering University,Zhengzhou 450002,china 2 department of Mathematics,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,china 1. department of information Research College of Information Engineering Information Engineering University Zhengzhou 450002 China2. Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A new result on the nonexistence of generalized bent functions is presented by using properties of the decomposition law of primes in cyclotomic fields and properties of solutions of some Diophantine equations. At the same time,a method is given which can be used to simplify the known results. Then we give the bounds and the meaning in algebraic number theory of the parameters in our results.

关键词： generalized bent function integral basis class group genus theory

Object Replication and CORBA Fault Tolerant Object Service

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Wuhan University Journal of Natural Sciences 2001年第Z1期6卷 268-277页

作者： Yeh Yao ming 1,Sun Wen Da 2,Chen Yeong Sheng 2 1. department of information and Computer Engineering, Taiwan Normal University, Taipei,china 2. department of information Management,Hwa Hsia College of Technology and Commerce, Taipei,china department of information and Computer Engineering Taiwan Normal University Taipei China department of information Management Hwa-Hsia College of Technology and Commerce Taipei China

CORBA (Common Object Request Broker Architecture) provides 16 Common Object Services for distributed application development, but none of them are fault tolerance related services. In this paper, we propose a replicated object based Fault Tolerant Object Service (FTOS) for CORBA environment. Two fault tolerant mechanisms are provided in FTOS including dynamic voting mechanism and object replication mechanism. The dynamic voting mechanism uses majority voting strategy to ensure object state consistency in failure situations. The object replication mechanism can help system administrators to replicate and start up objects easily. Our implementation provides a library according to the style of COSS. With this library, programmers can develop distributed applications with fault tolerance capability very easily.

关键词： CORBA replicated object dynamic voting object replication

Generalized gradient projection neural networks for nonsmooth optimization problems

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Science china(information Sciences) 2010年第5期53卷 990-1005页

作者： LI GuoCheng 1 , SONG ShiJi 2 ? & WU Cheng 2 1 department of Mathematics, Beijing information Science and Technology University, Beijing 100192, china 2 department of Automation, Tsinghua University, Beijing 100084, china 1. department of Mathematics Beijing Information Science and Technology University Beijing 100192 China2. Department of Automation Tsinghua University Beijing 100084 China

Generalized gradient projection neural network models are proposed to solve nonsmooth convex and nonconvex nonlinear programming problems over a closed convex subset of R n . By using Clarke’s generalized gradient, the neural network modeled by a differential inclusion is developed, and its dynamical behavior and optimization capabilities both for convex and nonconvex problems are rigorously analyzed in the framework of nonsmooth analysis and the differential inclusion theory. First for nonconvex optimization problems, the quasi convergence results similar to those achieved by previous work are proved. For convex optimization problems, the global convergence results are proved, i.e. any trajectory of the neural network converges to an asymptotically stable equilibrium point, which is an optimal solution of the primal problem whenever it exists. This result remains valid even if the initial condition is chosen outside the feasible set. In addition, an asymptotic control result involving a Tykhonov like regularization shows that any trajectory of the revised neural network can be forced to converge toward a particular optimal solution of the primal problem. Finally, two simulation optimization algorithms for solving the optimization and control problems are designed respectively, and three typical simulation experiments are illustrated to present the accuracy and efficiency of theoretical convergence results of this paper.

关键词： nonsmooth optimization problem generalized gradient projection networks differential inclu sions convergence

A fast stereoscopic video coding algorithm based on JMVM

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Science china(information Sciences) 2011年第6期54卷 1218-1226页

作者： DENG ZhiPin 1,2 , JIA KeBin 1 , CHAN YuiLam 2 , FU ChangHong 2 & SIU WanChi 2 1 department of Electronic information & Control Engineering, Beijing University of Technology, Beijing 100124, china 2 department of Electronic information Engineering, Hong Kong Polytechnic University, Hong Kong, china 1. department of Electronic information & Control Engineering Beijing University of Technology Beijing 100124 China2. Department of Electronic Information Engineering Hong Kong Polytechnic University Hong Kong China

In order to exploit the intra-view and inter-view dependencies in stereo video coding, a fast joint motion and disparity estimation algorithm is proposed in this paper. An efficient search strategy based on the motion-disparity constraint is developed, in which both the motion and disparity vectors can be obtained simultaneously with low complexity. Moreover, a credible initial predictive vector set is designed with the aid of the temporal and spatial neighboring blocks so that the coding efficiency can be further enhanced. The experimental results demonstrate that the proposed algorithm can reduce more than 96% coding time compared with the JMVM full search with a negligible quality drop.

关键词： H.264 stereoscopic video coding disparity estimation motion estimation