检索结果-内蒙古大学图书馆

International conference on Computational Science, ICCS 2001

International conference on Computational Science, ICCS 2001

ISBN: (纸本)3540422331

The proceedings contain 119 papers. The special focus in this conference is on Digital Imaging applications and Environmental Modeling. The topics include: Densification of digital terrain elevations using shape from shading with single satellite imagery;PC-based system for calibration, reconstruction, processing, and visualization of 3D ultrasound data based on a magnetic-field position and orientation sensing system;automatic real-time XRII local distortion correction method for digital linear tomography;meeting the computational demands of nuclear medical imaging using commodity clusters;an image registration algorithm based on cylindrical prototype model;an area-based stereo matching using adaptive search range and window size;methods of sensitivity theory and inverse modeling for estimation of source term and risk/vulnerability areas;the simulation of photochemical smog episodes in hungary and central europe using adaptive gridding models;numerical solution of the aerosol condensation/evaporation equation;efficient treatment of large-scale air pollution models on supercomputers;pattern search methods for use-provided points;advantages of parallel computing and graphical investigating techniques;adaptive load balancing for MPI programs;performance and irregular behavior of adaptive task partitioning;optimizing register spills for eager functional languages;mapping parallel programs onto distributed computer systems with faulty elements;an adaptive learning framework for optimizing artificial neural networks;solving nonlinear differential equations by a neural network method;fuzzy object blending in 2D;an adaptive neuro-fuzzy approach for modeling and control of nonlinear systems;the match fit algorithm;automatic implementation and simulation of qualitative cognitive maps and inclusion-based approximate reasoning.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Detailed analysis of load rejection test of autonomous synchronous generator

Detailed analysis of load rejection test of autonomous synch...

引用

International conference on Electrical Machines and Systems (ICEMS)

作者： R. Wamkeue I. Kamwa Département des sciences appliquées Université du Quibec en Abitibi-Témiscamingue Rouyn-Noranda Canada Institut de recherche d'Hydro-Québec Varennes Canada

The paper outlines the theory and reasoning behind concise load rejection test analysis of autonomous synchronous generators. A new concept of generalized linear electromechanical hybrid state space synchronous machine model is derived for this purpose. The work is also concerned with numerical implementation and simulation of the new theory. Practical applications of the proposed concept in the dynamic performance prediction of 100% load rejection of synchronous generator with successively pure inductive load, pure resistive loads and combined resistive and reactive load proved the effectiveness of the model. numerical results reveals that overvoltage generally follow load rejection tests of resistive loads.

关键词： Synchronous generators Circuit testing Synchronous machines Performance evaluation Voltage control Power system harmonics Electric variables control Board of Directors State-space methods numerical simulation

来源：评论

学校读者我要写书评

暂无评论

Reliable LQG control with sensor failures

引用

IEE PROCEEDINGS-CONTROL theory AND applications 2000年第4期147卷 433-439页

作者： Yang, GH Wang, JL Soh, YC Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

The paper is concerned with reliable LQG controller design for linear systems with sensor failures. A model of sensor failures more practical than outage is adopted. Two procedures of designing reliable LQG controllers are presented: stabilising solutions of three coupled Riccati equations;and solutions to one Riccati equation and two linear matrix inequalities. The resulting control systems are guaranteed to be robustly stable and with a known cost bound on the LQG cost against sensor failures. Algorithms are developed to obtain a solution and illustrated via numerical examples.

关键词： algebra Riccati equations linear matrix inequality linear quadratic Gaussian control asymptotic stability sensor failures LQG control robust control Stability in control theory Optimal control closed loop systems state feedback matrix algebra Control system analysis and synthesis methods linear systems

来源：评论

学校读者我要写书评

暂无评论

Solution of infinite linear systems by automatic adaptive iterations

引用

linear algebra AND ITS applications 2000年第1-3期318卷 209-225页

作者： Favati, P Lotti, G Menchi, O Romani, F Univ Pisa Dipartimento Informat I-56100 Pisa Italy Univ Parma Dipartimento Matemat I-43100 Parma Italy CNR IMC I-56010 Pisa Italy

The problem of approximating the solution of infinite linear systems finitely expressed by a sparse coefficient matrix in block Hessenberg form is considered. The convergence of the solutions of a sequence of truncated problems to the infinite problem solution is investigated A family of algorithms, some of which are adaptive, is introduced, based on the application of the Gauss-Seidel method to a sequence of truncated problems of increasing size n(i) with non-increasing tolerance 10(-ti). These algorithms do not require special structural properties of the coefficient matrix and they differ in the way the sequences {n(i)} and {t(i)} are generated. The testing has been performed on both infinite problems arising from the discretization of elliptical equations on unbounded domains and stochastic problems arising from queueing theory. Extensive numerical experiments permit the evaluation of the various strategies and suggest that the best trade-off between accuracy and computational cost is reached by some of the adaptive algorithms. (C) 2000 Elsevier Science Inc. All rights reserved. AMS classification: 65F10;65N22;60K25.

关键词： infinite linear systems iterative methods

来源：评论

学校读者我要写书评

暂无评论

Preconditioning strategies for linear systems arising in tire design

引用

numerical linear algebra WITH applications 2000年第7-8期7卷 743-757页

作者： Sosonkina, M Melson, JT Saad, Y Watson, LT Univ Minnesota Dept Comp Sci Duluth MN 55812 USA Michelin Amer Res & Dev Corp Greenville SC 29602 USA Univ Minnesota Dept Comp Sci & Engn Minneapolis MN 55455 USA Virginia Polytech Inst & State Univ Dept Comp Sci Blacksburg VA 24061 USA Virginia Polytech Inst & State Univ Dept Math Blacksburg VA 24061 USA

This paper discusses the application of iterative methods for solving linear systems arising in static tire equilibrium computation. The heterogeneous material properties, nonlinear constraints, and a three dimensional finite element formulation make the linear systems arising in tire design difficult to solve by iterative methods, An analysis of the matrix characteristics helps understand this behaviour, This paper focuses on two preconditioning techniques: a variation of an incomplete LU factorization with threshold and a multilevel recursive solver. We propose to adapt these techniques in a number of ways to work for a class of realistic applications. In particular, it was found that these preconditioners improve convergence only when a rather large shift value is added to the matrix diagonal. A combination of other techniques such as filtering of small entries, pivoting in preconditioning, and a special way of defining levels for the multilevel recursive solver are shown to make these preconditioning strategies efficient for problems in fire design, We compare these techniques and assess their applicability when the linear system difficulty varies for the same class of problems, Copyright (C) 2000 John Whey & Sons, Ltd.

关键词： incomplete LU factorization multilevel preconditioning ill-conditioned linear systems generalized minimum residual method

来源：评论

学校读者我要写书评

暂无评论

A parallel linear system solver for circuit simulation problems

引用

numerical linear algebra WITH applications 2000年第7-8期7卷 649-665页

作者： Bomhof, CW van der Vorst, HA Univ Utrecht Inst Math NL-3508 TA Utrecht Netherlands Philips Res Labs NL-5656 AA Eindhoven Netherlands

This paper presents a parallel mixed direct/iterative method for solving linear systems Ax = b arising from circuit simulation. The systems are solved by a block LU factorization with an iterative method for the Schur complement. The Schur complement is a small and rather dense matrix. Direct LU decomposition of the Schur complement takes too much time in order to achieve reasonable speedup results. Our iterative method for the Schur complement is often much faster than the direct LU approach. Moreover, the iterative method is better parallelizable. This results in a fast sequential and well parallelizable method. Copyright (C) 2000 John Wiley & Sons, Ltd.

关键词： preconditioner parallel iterative method mixed direct/iterative method sparse LU factorization circuit simulation iterative solution methods Schur complement GMRES

来源：评论

学校读者我要写书评

暂无评论

Design and evaluation of a linear algebra package for Java

Design and evaluation of a linear algebra package for Java

引用

ACM 2000 Java Grande conference

作者： Almasi, G. Gustavson, F.G. Moreira, J.E. Department of Computer Science Univ. Illinois at Urbana-Champaign Urbana IL 61801 United States IBM T.J. Watson Research Center P. O. Box 218 Yorktown Heights NY 10598 United States

ISBN: (纸本)1581132883

This paper describes the design of a high-performance linear algebra library for Java. linear algebra libraries such as ESSL and LAPACK are important tools of computational science and engineering, and have been available to C and Fortran programmers for quite a while. If Java is to become a serious language for the development of large scale numerical applications, it must provide equivalent functionality. From the many possible alternatives to accomplish this goal, we took the approach of designing a linear algebra library entirely in Java. This approach leads to good portability and maintainability of the code. It is also a good test of how far we can push Java performance. We adopted an object-oriented design in which the linear algebra operations are implemented as strategy design patterns. The higher level algorithms, optimized for the memory hierarchies of present-day machines, are described in a type independent manner. Type specific methods capture the lower level optimizations for operations on matrices of single-precision, double-precision, or complex numbers. We evaluate the performance of our linear algebra package on three different machines. Our preliminary results show that our Java library achieves up to 85% of the performance of the highly optimized ESSL.

关键词： Java programming language

来源：评论

学校读者我要写书评

暂无评论

Using FFT-based techniques in polynomial and matrix computations: Recent advances and applications

引用

numerical FUNCTIONAL ANALYSIS AND OPTIMIZATION 2000年第1-2期21卷 47-66页

作者： Bini, DA Univ Pisa Dipartimento Matemat I-56100 Pisa Italy

Computations with univariate polynomials, like the evaluation of product, quotient, remainder, greatest common divisor, etc, are closely related to linear algebra computations performed with structured matrices having the Toeplitz-like or the Hankel-like structures. The discrete Fourier transform, and the FFT algorithms for its computation, constitute a powerful tool for the design and analysis of fast algorithms for solving problems involving polynomials and structured matrices. We recall the main correlations between polynomial and matrix computations and present two recent results in this field: in particular, we show how Fourier methods can speed up the solution of a wide class of problems arising in queueing theory where certain Markov chains, defined by infinite block Toeplitz matrices in generalized Hessenberg form, must be solved. Moreover, we present a new method for the numerical factorization of polynomials based on a matrix generalization of Koenig's theorem. This method, that relies on the evaluation/interpolation technique at the Fourier points, reduces the problem of polynomial factorization to the computation of the LU decomposition of a banded Toeplitz matrix with its rows and columns suitably permuted. numerical experiments that show the effectiveness of our algorithms are presented.

关键词： Toeplitz matrices FFT polynomial computations polynomial factorization Markov chains Koenig's theorem cyclic reduction

来源：评论

学校读者我要写书评

暂无评论

Sparse pattern selection strategies for robust Frobenius-norm minimization preconditioners in electromagnetism

引用

numerical linear algebra WITH applications 2000年第7-8期7卷 667-685页

作者： Carpentieri, B Duff, IS Giraud, L CERFACS F-31057 Toulouse France Rutherford Appleton Lab Didcot OX11 0QX Oxon England

We consider preconditioning strategies for the iterative solution of dense complex symmetric non-Hermitian systems arising in computational electromagnetics. We consider in particular sparse approximate inverse preconditioners that use static non-zero pattern selection. The novelty of our approach comes from using a different non-zero pattern selection procedure for the original matrix from that for the preconditioner and from exploiting geometric or topological information from the underlying meshes instead of using methods based on the magnitude of the entries. The numerical and computational efficiency of the proposed preconditioners are illustrated on a set of model problems arising both from academic and from industrial applications. The results of our numerical experiments suggest that the new strategies are viable approaches for the solution of large-scale electromagnetic problems using preconditioned Krylov methods. In particular, our strategies are applicable when fast multipole techniques are used for the matrix-vector product on parallel distributed memory computers. Copyright (C) 2000 John Wiley & Sons, Ltd.

关键词： preconditioning techniques Frobenius-norm minimization method non-zero pattern selection strategies electromagnetic scattering applications

来源：评论

学校读者我要写书评

暂无评论

Software-implemented fault detection for high-performance space applications

Software-implemented fault detection for high-performance sp...

引用

International conference on Dependable Systems and Networks

作者： Turmon, M Granat, R Katz, DS CALTECH Jet Prop Lab Pasadena CA 91109 USA

ISBN: (纸本)0769507077

We describe and test a software approach to overcoming radiation-induced errors in spaceborne applications running on commercial off-the-shelf components. The approach uses checksum methods to validate results returned by a numerical subroutine operating subject to unpredictable errors in data. We can treat subroutines that return results satisfying a necessary condition having a linear form;the checksum tests compliance with this condition. We discuss the theory and practice of setting numerical tolerances to separate errors caused by a fault from those inherent infinite-precision numerical calculations. We test both the general effectiveness of the linear fault tolerant schemes we propose, and the correct behavior of our parallel implementation of them.

关键词： Computer system recovery

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：