检索结果-南通市图书馆

SWITCHING CONTROL: FROM SIMPLE RULES TO COMPLEX CHAOTIC systemS

在线全文

学校读者我要写书评

暂无评论

Journal of systems Science & Complexity 2003年第3期16卷 404-413页

作者： LU Jinhu(institute of systems {2., academy of mathematics and system sciences, chinese academy of sciences, beijing 100080, china ) institute of systems {2. Academy of Mathematics and System Sciences Chinese Academy of Sciences 北京 100080

This paper reviews and introduces some simple switching piecewise-linear controllers, which can generate complex chaotic behaviors from simple switching *** mechanism of simple switching rules creating complex chaotic... 详细信息

关键词： switching control simple rules complex systems

Conjugate Gradient Methods with Armijo-type Line Searches

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2002年第1期18卷 123-130页

作者： Yu-Hong DAIState Key Laboratory of Scientific and Engineering Computing, institute of Computational mathematics,{2., chinese academy of sciences, beijing 100080, china State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

Two Armijo-type line searches are proposed in this paper for nonlinear conjugate gradient methods. Under these line searches, global convergence results are established for several famous conjugate gradient methods, i... 详细信息

关键词： Unconstrained optimization conjugate gradient method line search global convergence

Supervisory Control of Extended Timed Event Graphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2003年第2期19卷 281-288页

作者： Zhi-bing Zhuo, Wen-de Cheninstitute of systems Science,{2., chinese academy of sciences, beijing 100080, china institute of systems Science Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

Abstract This paper describes the dynamic behavior of extended timed event graphs related to place delay in the dioid framework. By Cofer and Garg's supervisory control theory^|3|, we address control problems of extended timed events graphs. Supervisory control of extended timed event graphs (a class of discrete event dynamic systems) is studied in the dioid framework, a necessary and sufficient condition for the ideals of the set of firing time sequences of transitions to be controllable is presented. We prove all the strongly controllable subsets can form a complete lattice.

关键词： Keywords Supervisory control extended timed event graph (ETEG) dioid strong controllability discrete event dynamic system (DEDS)

The Approximation Theorem of Convolution Operator in △~p Set-valued Function Space

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2002年第3期18卷 495-500页

作者： Pei-xin Yeinstitute of mathematics,{2., chinese academy of Science, beijing institute of mathematics Academy of Mathematics and System Sciences Chinese Academy of Science Beijing 100080 China

The paper is a contribution to the problem of approximating random set with values in a separable Banach space. This class of set-valued function is widely used in many *** investigate the properties of p-bounded integrable random set. Based on this we endow it with △p metric which can be viewed as a integral type hausdorff metric and present some approximation theorem of a class of convolution operators with respect to △p metric. Moreover we also can establish analogous theorem for other integral type operator in △p space.

关键词： Set-valued function random set convolution operator △~p space approximation theorem

On the coupled NBEM and FEM for a class of nonlinear exterior Dirichlet problem in R^(2.)

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2004年第z1期47卷 181-189页

作者： WU Zhengpeng, KANG Tong & YU Dehaoinstitute of Computational mathematics and Scientific/Engineering Computing,{2., chinese academy of sciences, beijing 100080, china Department of Applied mathematics, beijing Broadcasting institute, beijing 10002., china Combinatorial and Computational mathematics Center, Pohang University of Science and Technology, Phoang 790-784, Republic of Korea chinese Acad Sci Acad Math & Syst Sci Inst Computat Math & Sci Engn Comp Beijing 100080 Peoples R China beijing Broadcasting Inst Dept Appl Math Beijing 100024 Peoples R China Pohang Univ Sci & Technol Combinatorial & Computat Math Ctr Phoang 790784 South Korea

In this paper, based on the natural boundary reduction advanced by Feng and Yu, we couple the finite elementapproach with the natural boundary element method to study theweak solvability and Galerkin approximation of a class ofnonlinear exterior boundary value problems. The analysis is mainlybased on the variational formulation with *** provethe error estimate of the finite element solution and obtain theasymptotic rate of convergence. Finally, we also give anumerical example.

关键词： natural boundary integral method, finite element method, coupling method, error estimate.

Profitless delays for extinction in nonautonomous Lotka-Volterra system

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 2001年第4期6卷 210-216页

作者： Shengqiang LIU and Lansun CHEN academy of mathematics and system sciences, chinese academy of sciences,{2., china e-mail: Lsq@math03. math. ac. cn academy of mathematics and {2. sciences Chinese Academy of Sciences Beijing 100080 China

We study the delayed periodic n-species Lotka-Volterra systems where the growth rate of each species is not always positive. The sufficient conditions for the extinction that are independent of the delays are obtained. Some known results are improved and generalized. Our results suggest that under some conditions, the introduction and the variance of the time delays can be both harmless and profitless. Discussion about the effect of time delays on the extinction of the system is also advanced.

关键词： competitive Lotka-Volterra system periodic profitless delays extinction

A new trust region algorithm for image restoration

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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,{2., 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.

ON THE SOLVABILITY OF GENERAL LINEAR METHODS FOR DISSIPATIVE DYNAMICAL systemS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 2000年第6期18卷 633-638页

作者： Ai-guo Xiao (Department of mathematics, Xiangtan University, Xiangtan 411105, china.) ({2. of Computational mathematics and Scientific/Engineering Computing, chinese academy of sciences, beijing 100080, china) 湘潭大学湖南湘潭 4111105

The main purpose of the present paper is to examine the existence and local uniqueness of solutions of the implicit equations arising in the application of a weakly algebraically stable general linear methods to dissipative dynamical systems, and to extend the existing relevant results of Runge-Kutta methods by Humphries and Stuart(1994). [ABSTRACT FROM AUTHOR]

关键词： general linear methods dissipative dynamical systems weak algebraic stability solvability

CONVERGENCE OF (0,1,2.3) INTERPOLATION ON AN ARBITRARY system OF NODES

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 2001年第2期19卷 151-156页

作者： Ying-guang Shi (institute of Computation, Hunan Normal University, Changsha 410081, china) (institute of Computational mathematics and Scientific/Engineering Computing, academy of mathematics and systems sciences, chinese academy of sciences, beijing 100 湖南师范大学湖南长沙 410081

Provides information on a study which simplified and improved convergence of (0,1,2.3) interpolation on an arbitrary system of nodes. Definitions and notations; Results; Conjectures.

关键词： Hermite interpolation Hermite-Fejer interpolation convergence