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Chinese Optics Letters 2010年第4期8卷 381-383页

作者：余卫宇田菁 school of electronic and Information engineering South China University of Technology school of electrical and electronic engineering Nanyang Technological University

A new image coding approach is proposed by controlling the quantization step via minimizing the perceptual distortions（in terms of image＇s contrast measurement）.The proposed method is a rate-oriented contrast-based approach,which is in contrast to the conventional quality-oriented contrast-based image *** algorithm achieves a higher perceptual quality performance against several methods developed previously.

关键词： Visual communication

A regularization method in the electromagnetic inverse scattering problem

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Progress in Natural Science:Materials International 2007年第3期17卷 346-351页

作者： XIONG Xiaoyun, ZHAO Yanwen and NIE Zaiping (school of electronic engineering, university of electronic Science and technology of china, Chengdu 610054, china) school of electronic engineering University of Electronic Science and Technology of China Chengdu 610054 China

Based on the normalization of measurement data equations of the inverse scattering problem, a new regularization matrix is proposed. It can eliminate the unfavorable effects caused by difference of distances between field-point or source-point and target region, reduce the loss of useful information in regularization procedure, and decrease condition numbers of the ill-posed problems. Inversion for conductivity distribution of two-dimensional axisymmetric inhomogeneous media is carried out by combing this new regularization method with distorted Born iterative method. Simulation results show that compared with the conventional method, the new regularization method is of better stability, quicker convergence, higher accuracy of inversion and higher resolution.

关键词： inverse scattering regularization distorted Born iterative method.

An improved model of Robinson equivalent circuit analytical model

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Science china(Technological Sciences) 2010年第7期53卷 1993-1999页

作者： MAO XiangYu & DU PingAn school of Mechatronics engineering, university of electronic Science and technology of china, Chengdu 611731, china school of Mechatronics engineering University of Electronic Science and Technology of China Chengdu China

The Robinson equivalent circuit analytical model can be used only in calculating shielding effectiveness of enclosure with the same multi-holes in one wall, but cannot be used in different multi-holes in two walls. According to the practical requirement, this article uses Konefal's and Farhana's characteristic impedance of apertures to improve the equivalent circuit analytical model in different multi-holes in two walls. The improved equivalent circuit analytical model is more useful than Robinson equivalent circuit analytical model. In the article, all kinds of enclosures are simulated by TLM (Transmission-Line Matrix method) to prove that this improved model is feasible in multimode.

关键词： equivalent circuit improved model apertures shielding effectiveness TLM (Transmission-Line Matrix method)

Efficient CRT-based residue-to-binary converter for the arbitrary moduli set

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Science china(Information Sciences) 2011年第1期54卷 70-78页

作者： CHEN JianWen & YAO RuoHe school of electronic and Information engineering,South china university of technology, Guangzhou 510640,china school of electronic and Information engineering South China University of Technology Guangzhou China

The conversion from residue to weighted binary representation plays an important role in the residue number *** on Chinese Remainder Theorem,a new residue-to-binary converter using arbitrary moduli set is *** new converter uses the difference-correction algorithm for the conversion output and eliminates the modulo M operation,where M is the dynamic range of the residue number *** sizes of the multipliers and modular multipliers in the new converter are small,thereby reducing the area and delay of the proposed *** and synthesis results indicate that the new converter is more area-time effcient than the published converters based on Chinese Remainder Theorem.

关键词： RNS Chinese Remainder Theorem difference correction modular arithmetic residue-to-binary arbitrary moduli set

Dynamics of the generalized 3x + 1 function determined by its fractal images

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Progress in Natural Science:Materials International 2008年第2期18卷 217-223页

作者： Xingyuan Wang ,Xuejing Yu school of electronic & Information engineering,Dalian university of technology,Dalian 116024,china school of electronic & Information engineering Dalian University of Technology Dalian 116024 China

Two different complex maps were obtained by generalizing 3x + 1 function to the complex plane,and fractal images for these two complex maps were constructed by using escape time,stopping time and total stopping time arithmetic. The dynamics of the generalized 3x + 1 function based on the structural characteristics of the fractal images was studied. We found that: (1) the size and structure of the stable regions,stopping regions,total stopping regions,and divergent regions for the three types of fractal images depend on convergence rate of the map on the x and y axes. (2) The black stable regions constructed,respectively,by escape time and total stopping time are almost overlapped,demonstrating that 3x + 1 function converged steadily. (3) All of the three fractal images are symmetric to the real axis. The structures on the neighborhood of positive integer number are symmetric to a perpendicular line,which is corresponding to the point or its nearby points on the x axis. And the structures have complicated fractal structure characteristics. These findings indicate that the generalized 3x + 1 function on integer number and its neighborhood contains plentiful information in the complex plane.

关键词： Generalized 3x + 1 function Fractal images Dynamics

Surrogate model-assisted interactive genetic algorithms with individual’s fuzzy and stochastic fitness

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控制理论与应用（英文版） 2010年第2期8卷 189-199页

作者： Xiaoyan SUN, Dunwei GONG (school of Information and electrical engineering, china university of Mining and technology, Xuzhou Jiangsu 221116, china) school of Information and electrical engineering China University of Mining and Technology Xuzhou Jiangsu China

We propose a surrogate model-assisted algorithm by using a directed fuzzy graph to extract a user’s cognition on evaluated individuals in order to alleviate user fatigue in interactive genetic algorithms with an individual’s fuzzy and stochastic fitness. We firstly present an approach to construct a directed fuzzy graph of an evolutionary population according to individuals’ dominance relations, cut-set levels and interval dominance probabilities, and then calculate an individual’s crisp fitness based on the out-degree and in-degree of the fuzzy graph. The approach to obtain training data is achieved using the fuzzy entropy of the evolutionary system to guarantee the credibilities of the samples which are used to train the surrogate model. We adopt a support vector regression machine as the surrogate model and train it using the sampled individuals and their crisp fitness. Then the surrogate model is optimized using the traditional genetic algorithm for some generations, and some good individuals are submitted to the user for the subsequent evolutions so as to guide and accelerate the evolution. Finally, we quantitatively analyze the performance of the presented algorithm in alleviating user fatigue and increasing more opportunities to find the satisfactory individuals, and also apply our algorithm to a fashion evolutionary design system to demonstrate its efficiency.

关键词： Interactive genetic algorithms User fatigue Surrogate model Directed fuzzy graph Fuzzy entropy

Adaptive interactive genetic algorithms with individual interval fitness

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Progress in Natural Science:Materials International 2008年第3期18卷 359-365页

作者： Dunwei Gong , Guangsong Guo, Li Lu, Hongmei Ma school of Information and electrical engineering, china university of Mining & technology, Xuzhou 221008, china school of Information and electrical engineering China University of Mining & Technology Xuzhou 221008 China

It is necessary to enhance the performance of interactive genetic algorithms in order to apply them to complicated optimization prob- lems successfully. An adaptive interactive genetic algorithm with individual interval fitness is proposed in this paper in which an indi- vidual fitness is expressed by an interval. Through analyzing the fitness, information reflecting the distribution of an evolutionary population is picked up, namely, the difference of evaluating superior individuals and the difference of evaluating a population. Based on these, the adaptive probabilities of crossover and mutation operators of an individual are presented. The algorithm proposed in this paper is applied to a fashion evolutionary design system, and the results show that it can find many satisfactory solutions per generation. The achievement of the paper provides a new approach to enhance the performance of interactive genetic algorithms.

关键词： Optimization Genetic algorithm Interaction Interval Probability of genetic operator

Transient temperature field of a friction pair in a HVD device of a belt conveyor

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Mining Science and technology 2010年第6期20卷 904-907页

作者： XIE Fangwei, HOU Youfu school of Mechanical and electrical engineering, china university of Mining & technology, Xuzhou 221008, china school of Mechanical and electrical engineering China University of Mining & Technology Xuzhou 221008 China

To show the distribution of a temperature field on a steel disk and to prolong the service life of a friction pair in a Hy-dro-Viscous Drive (HVD) device, a theoretical model of a transient temperature field was established, based on the theory of heat conduction. This theoretical model was solved using a finite element method. The results show that the surface temperature of the steel disk does not increase consistently as a function of the radius; the highest temperature appears short of the maximum radius. The relationship between the surface temperature and the mixed friction time is exponential. With a friction time of 15 s, the tem-perature reached 465.9 °C. Simultaneously, the internal thermal stress is larger than the yield stress of the material, causing a warping deformation of the steel disk. The largest axial deformation is 0.32 mm. The results of the experiment suggest that the de-formation is the same as that obtained from numerical simulation. Therefore, deformation of the steel disk must be considered dur-ing the study of the characteristics of a HVD.

关键词：温度场分布瞬态温度场 HVD 摩擦副皮带输送机装置表面温度最大半径

On the maximum likelihood method for target localization using MIMO radars

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Science china(Information Sciences) 2010年第10期53卷 2127-2137页

作者： XIA Wei , HE ZiShu & LIAO YuYu school of electronic engineering, university of electronic Science and technology of china, Chengdu 611731, china school of electronic engineering University of Electronic Science and Technology of China Chengdu China

A multiple-input multiple-output (MIMO) radar uses multiple antennas to simultaneously transmit multiple independent probing signals, and uses multiple antennas to receive the backscattered signals. The modeling of MIMO radar with transmit spatial diversity and coherent reception is addressed herein. The maximum likelihood (ML) method for parameter estimation using MIMO radars is considered, and two approximate ML algorithms are proposed. In the uniform noise scenario, one of the proposed algorithms performs similarly to the delay-and-sum beamformer which is optimal in the ML sense in single target case, while it outperforms the other proposed approximate ML algorithm at the cost of more computational load. In the non-uniform noise scenario, the proposed approximate ML algorithms both outperform the delay-and-sum beamformer. The efficiency of the proposed methods is validated by the simulation results.

关键词： maximum-likelihood multiple-input multiple-output (MIMO) radars parameter estimation