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Communications in Theoretical Physics 2001年第7期36卷 11-18页

作者： GUO Han-Ying LI Yu-Qi WU Ke Institute of Theoretical Physics Academia Sinica P.O. Box 2735 Beijing 100080 China Institute of Theoretical Physics Academia Sinica P.O. Box 2735 Beijing 100080 China Institute of Theoretical Physics Academia Sinica P.O. Box 2735 Beijing 100080 China

We present the symplectic algorithm in the Lagrangian formalism for the Hamiltonian systems by virtue of the noncommutative differential calculus with respect to the discrete time and the Euler-Lagrange cohomological ... 详细信息

关键词： symplectic algorithm, Lagrangian formalism, Euler-Lagrange cohomology

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The restricted EM algorithm under linear inequalities in a linear model with missing data

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Science China Mathematics 2005年第6期48卷 819-828页

作者： ZHENG Shurong, SHI Ningzhong & GUO Jianhua School of Mathematics and Statistics, Northeast Normal University, Changchun 130024, China Institute of Mathematics, Jilin University, Changchun 130012, China 1. School of Mathematics and Statistics Northeast Normal University 130024 Changchun China 2. Institute of Mathematics Jilin University 130012 Changchun China

This paper discusses the maximum likelihood estimate of β under linear inequalities A0β≥ a in a linear model with missing data, proposes the restricted EM algo rithm and proves the convergence.

关键词： EM algorithm, linear model, maximum likelihood estimate, missing data.

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An integrated decision method for prediction of tropical cyclone movement by using genetic algorithm

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Science China Earth Sciences 2005年第3期48卷 429-440页

作者： YANG Yuanqin1 & WANG Jizhi2 1. National Meteorological Center, Beijing 100081,China 2. Chinese Academy of Meteorological Sciences, Beijing 100081, China 1. National Meteorological Center 100081 Beijing China 2. Chinese Academy of Meteorological Sciences 100081 Beijing China

In this study an integrated decision method for the multi-prediction results of tropical cyclone movements by using genetic algorithm (GA) has been adopted. A genetic learning artifi- cial neural network (GLANN) as a learning mechanism for track prediction was developed through training with the huge samples of typhoon tracks from 1884 to 2002. The prediction of typhoon motion is to consider how to suit the dynamic change of environment, where typhoon passed through. The neural network structure is described by GA. A fitness function for choice of GA is given to approach the maximum of fitness (the minimum of the errors). Parallel comparing analyses for prediction abilities of unusual typhoon tracks in recent years by GLANN with multi-forecast methods were conducted. More types of cases were employed in the comparing analyses, which consist of the typhoon, Winnie, No.11, in 1997, characterized by a long life over the ocean and in the mainland with severe effect on China, the 10 unusual typhoon tracks in the 1990s, the tracks with landfall and affected action in 1998 and the typhoons born in the Northwestern Pacific and the South China Sea in 2000, including the 24—48 h forecast, etc. The results indicated that for prediction ability of typhoon tracks, specially for unusual typhoons, GA decision-making developed in this study is superior to the others.

关键词： genetic algorithm, integrated decision, prediction of tropical cyclone.

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A new trust region algorithm for image restoration

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Science China Mathematics 2005年第2期48卷 169-184页

作者： WEN Zaiwen & WANG Yanfei State Key Laboratory of Scientific Engineering Computing, Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080, China National Key Laboratory on Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 100101, China 1. State Key Laboratory of Scientific Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences 100080 Beijing China 2. National Key Laboratory on Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China

The image restoration problems play an important role in remote sensing and astronomical image analysis. One common method for the recovery of a true image from corrupted or blurred image is the least squares error (LSE) method. But the LSE method is unstable in practical applications. A popular way to overcome instability is the Tikhonov regularization. However, difficulties will encounter when adjusting the so-called regularization parameter a. Moreover, how to truncate the iteration at appropriate steps is also challenging. In this paper we use the trust region method to deal with the image restoration problem, meanwhile, the trust region subproblem is solved by the truncated Lanczos method and the preconditioned truncated Lanczos method. We also develop a fast algorithm for evaluating the Kronecker matrix-vector product when the matrix is banded. The trust region method is very stable and robust, and it has the nice property of updating the trust region automatically. This releases us from tedious finding the regularization parameters and truncation levels. Some numerical tests on remotely sensed images are given to show that the trust region method is promising.

关键词： trust region algorithm, image restoration, Lanczos method, Kronecker matrix-vector product, preconditioning.

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Ant System algorithm Research and Its Applications

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High Technology Letters 2002年第4期8卷 91-96页

作者：汪镭 Wu Qidi Qiao Fei Information and Control Dept. of Tongji University Shanghai 200092 P.R.China

In this paper, systematic review on Ant System (AS) algorithm research and application is made, and the authors works of introducing As algorithm into continuous space application are summarized. Then the applicabil... 详细信息

关键词： ant system algorithm, continuous space optimization

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Immune and Genetic algorithm Based Assembly Sequence Planning

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Journal of Donghua University(English Edition) 2004年第6期21卷 38-42页

作者：杨建国李蓓智俞雷金宇松 College of Mechanical Engineering Dong Hua University Shanghai 200051professor College of Mechanical Engineering Dong Hua University Shanghai 200051

In this paper an assembly sequence planning model inspired by natural immune and genetic algorithm (ASPIG) based on the part degrees of freedom matrix (PDFM) is proposed, and a proto system — DSFAS based on the ASPIG is introduced to solve assembly sequence problem. The concept and generation of PDFM and DSFAS are also discussed. DSFAS can prevent premature convergence, and promote population diversity, and can accelerate the learning and convergence speed in behavior evolution problem.

关键词： assembly, assembly sequence, automatic planning, immune algorithm, genetic algorithm

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Stability and Robustness Analysis of an Adaptive algorithm for Quasi-periodic Disturbances Rejection

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Journal of Donghua University(English Edition) 2004年第6期21卷 49-53页

作者：徐昱琳张五一杨向萍 Electrical Engineering Dept. Zhongyuan Institute of Technology Zhengzhou 450007 Dr Electrical Engineering Dept. Zhongyuan Institute of Technology Zhengzhou 450007 School of Mechanical Engineering Donghua University Shanghai 200051

Winding and web transport systems are subjected to quasi-periodic disturbances of the web tension due to the eccentricity and the non-circularity of the reel and rolls. The disturbances induced by the non-circularity and eccentricity of the rolls are quasi-periodic with a frequency that varies with their rotation speed. An adaptive method of rejection of these disturbances is proposed in this paper. It is based on a phase-locked loop structure that estimates simutaneously the phase and magnitude of the perturbation and then cancels it. This algorithm can be plugged in an existing industrial controller. The stability and robustness of the algorithm are also discussed. The ability of the algorithm to reject quasi-periodic disturbances with slowly varying frequencies is shown through simulation results.

关键词： Quasi-periodic disturbance rejection, web winding systems, adaptive algorithm, phase-locked loop, stability and robustness analysis

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Immune Genetic algorithm for Optimal Design

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Journal of Donghua University(English Edition) 2002年第4期19卷 16-19页

作者：杨建国李蓓智项前 College of Mechanical Engineering Dong Hua UniversityShanghai200051

A computing model employing the immune and genetic algorithm (IGA) for the optimization of part design is presented. This model operates on a population of points in search space simultaneously, not on just one point. It uses the objective function itself, not derivative or any other additional information and guarantees the fast convergence toward the global optimum. This method avoids some weak points in genetic algorithm, such as inefficient to some local searching problems and its convergence is too early. Based on this model, an optimal design support system (IGBODS) is *** has been used in practice and the result shows that this model has great advantage than traditional one and promises good application in optimal design.

关键词： automation, artificial immune system (AIS),Optimal design, evolutionary algorithm, genetic algorithm

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Research of the Kernel Operator Library Based on Cryptographic algorithm

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Journal of Donghua University(English Edition) 2001年第4期18卷 45-48页

作者：王以刚钱力黄素梅 Coll. of Info. Sci. and Technol. Dong Hua Univ. Shanghai 200051 China

The variety of encryption mechanism and algorithms which were conventionally used have some *** kernel operator library based on Cryptographic algorithm is put forward. Owing to the impenetrability of algorithm, the data transfer system with the cryptographic algorithm library has many remarkable advantages in algorithm rebuilding and optimization,easily adding and deleting algorithm, and improving the security power over the traditional algorithm. The user can choose any one in all algorithms with the method against any attack because the cryptographic algorithm library is extensible.

关键词： cryptology , cryptographic algorithm, algorithm library, cryptographic mechanism, operator

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Convergence of cascade algorithm for individual initial function and arbitrary refinement masks

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Science China Mathematics 2005年第3期48卷 350-359页

作者： CHEN Dirong HAN Min Department of Applied Mathematics Beijing University of Aeronautics and Aestronautics Beijing 100083China Department of Applied Mathematics Beijing University of Aeronautics and Aestronautics Beijing 100083China

The cascade algorithm plays an important role in computer graphics and wavelet analysis. For any initial function φn, a cascade sequence (φn)n∞=1 constructed by the iteration φn=Cnφn-1=1,2.. where Cαis defined by g∈Lp(R) In this paper, we characterize the convergence of a cascade sequence in terms of a sequence of functions and in terms of joint spectral radius. As a consequence, it is proved that any convergent cascade sequence has a convergence rate of geometry, i.e., ||φ+1-φn||Lp(R)=O((?)n)for some (?)∈(0.1i). The condition of sum rules for the mask is not required. Finally, an example is presented to illustrate our theory.

关键词： refinement mask, refinement equation, cascade algorithm, cascade sequence, sum rule, joint spectral radius.

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