检索结果-南通市图书馆

natural boundary ELEMENT METHOD FOR THREE DIMENSIONAL EXTERIOR HARMONIC PROBLEM WITH AN INNER PROLATE SPHEROID boundary

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2006年第2期24卷 193-208页

作者： Hong-ying Huang De-hao Yu LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

In this paper, we study natural boundary reduction for Laplace equation with Dirichlet or Neumann boundary condition in a three-dimensional unbounded domain, which is the outside domain of a prolate spheroid. We express the Poisson integral formula and natural integral operator in a series form explicitly. Thus the original problem is reduced to a boundary integral equation on a prolate spheroid. The variational formula for the reduced problem and its well-posedness are discussed. boundary element approximation for the variational problem and its error estimates, which have relation to the mesh size and the terms after the series is truncated, are also presented. Two numerical examples are presented to demonstrate the effectiveness and error estimates of this method.

关键词： natural boundary reduction Prolate spheroid boundary Finite element Exterior harmonic problem.

A PRECONDITIONER FOR COUPLING SYSTEM OF natural boundary ELEMENT AND COMPOSITE GRID FINITE ELEMENT

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2002年第2期20卷 165-174页

作者： Qi-ya Hu De-hao Yu Chinese Acad Sci Acad Math & Syst Sci ICMSEC LSEC Beijing 100080 Peoples R China

Discusses a coupling boundary element methods with finite element method for the Dirichlet exterior problems. Information on the natural boundary reduction; Discussion on the composite grid discretization; Details on ... 详细信息

关键词： natural boundary reduction composite grid error estimate preconditioner condition number

THE COUPLING OF natural boundary ELEMENT AND FINITE ELEMENT METHOD FOR 2D HYPERBOLIC EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2003年第5期21卷 585-594页

作者： De-haoYu Qi-kuiDu LSEC ICMSECAcademyofMathematicsandSystemSciencesChineseAcademyofSciencesBeijing100080China SchoolofMathematicsandComputerSciences NanjingNormalUniversityNanjing210097China

In this paper, we investigate the coupling of natural boundary element and finite element methods of exterior initial boundary value problems for hyperbolic equations. The governing equation is first discretized in time, leading to a time-step scheme, where an exterior elliptic problem has to be solved in each time step. Second, a circular artificial boundary TR consisting of a circle of radius R is introduced, the original problem in an unbounded domain is transformed into the nonlocal boundary value problem in a bounded subdomain. And the natural integral equation and the Poisson integral formula are obtained in the infinite domain Ω2 outside circle of radius R. The coupled variational formulation is given. Only the function itself, not its normal derivative at artificial boundary TR, appears in the variational equation, so that the unknown numbers are reduced and the boundary element stiffness matrix has a few different elements. Such a coupled method is superior to the one based on direct boundary element method. This paper discusses finite element discretization for variational problem and its corresponding numerical technique, and the convergence for the numerical solutions. Finally, the numerical example is presented to illustrate feasibility and efficiency of this method.

关键词： Hyperbolic equation natural boundary reduction Finite element Coupling Exterior problem.

THE OVERLAPPING DOMAIN DECOMPOSITION METHODFOR HARMONIC EQUATION OVER EXTERIORTHREE-DIMENSIONAL DOMAIN

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2000年第1期18卷 83-94页

作者： Ji-ining Wu De-bao Yu(State Key Laboratory of Scientific and Engineering Computing, Institute of ComputationalMathematics and Scientific/Engineering Computing, Chinese Academy of Sciences, Beijing100080, China) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京 100080

Presents a study which applied the overlapping domain decomposition method based on the natural boundary reduction to solve the boundary value problem of harmonic equation over domain. Methods to solve boundary value ... 详细信息

关键词： DDM exterior harmonic problem natural boundary reduction

boundary Integral Equations and A Posteriori Error Estimates

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2005年第1期10卷 35-42页

作者：余德浩赵龙花 Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Science Chinese Academy of Sciences P. O. Box 2719 Beijing 100080 China

Adaptive methods have been rapidly developed and applied in many fields of scientific and engi- neering computing. Reliable and efficient a posteriori error estimates play key roles for both adaptive finite element and boundary element methods. The aim of this paper is to develop a posteriori error estimates for boundary element methods. The standard a posteriori error estimates for boundary element methods are obtained from the classical boundary integral equations. This paper presents hyper-singular a posteriori er- ror estimates based on the hyper-singular integral equations. Three kinds of residuals are used as the esti- mates for boundary element errors. The theoretical analysis and numerical examples show that the hyper- singular residuals are good a posteriori error indicators in many adaptive boundary element computations.

关键词： boundary integral equation natural boundary reduction a posteriori error estimate hyper- singular residual pseudo-differential operator

DOMAIN DECOMPOSITION WITH NON-MATCHING GRIDS FOR COUPLING OF FEM AND natural BEM

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2005年第4期18卷 529-542页

作者： YANG Ju'e HU Qiya YU Dehao LSEC Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

In this paper, we introduce a domain decomposition method with non-matching grids for solving Dirichlet exterior boundary problems by coupling of finite element method （FEM） and natural boundary element method（BEM）. We first derive the optimal energy error estimate of the nonconforming approximation generated by this method. Then we apply a Dirichlet-Neumann（D-N） alternating algorithm to solve the coupled discrete system. It will be shown that such iterative method possesses the optimal convergence. The numerical experiments testify our theoretical results.

关键词： Domain decomposition non-matching grids natural boundary reduction multiplier space error estimate D-N alternating algorithm convergence.

THE ELLIPSOID ARTIFICIAL boundary METHOD FOR THREE-DIMENSIONAL UNBOUNDED DOMAINS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2009年第Z1期 196-214页

作者： Hongying Huang Information College,Zhejiang Ocean University,Zhoushan 316004,China Dehao Yu LSEC,ICMSEC,Academy of Mathematics and System Sciences,Chinese Academy of Sciences,Beijing 100080,China

The artificial boundary method is applied to solve three-dimensional exterior *** kind of rotating ellipsoids are chosen as the artificial boundaries and the exact arti-ficial boundary conditions are derived explicitly in terms of an infinite *** thewell-posedness of the coupled variational problem is *** is found that error esti-mates derived depend on the mesh size,truncation term and the location of the *** numerical examples are presented to demonstrate the effectiveness andaccuracy of the proposed method.

关键词： natural boundary reduction Oblate ellipsoid Prolate ellipsoid

On the Coupled of NBEM and CFEM for an Anisotropic Quasilinear Problem in an Unbounded Domain with a Concave Angle

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

American Journal of Computational Mathematics 2023年第1期13卷 185-198页

作者： Mingyue Tu Baoqing Liu School of Applied Mathematics Nanjing University of Finance and Economics Nanjing China

In this paper, based on the Kirchhoff transformation and the natural boundary element method, a coupled natural boundary element and curved edge finite element is applied to solve the anisotropic quasi-linear problem in an unbounded domain with a concave angle. By using the principle of the natural boundary reduction, we obtain the natural integral equation on the artificial boundary of circular arc boundary, and get the coupled variational problem and its numerical method. Then the error and convergence of coupling solution are analyzed. Finally, some numerical examples are verified to show the feasibility of our method.

关键词： Anisotropic Quasilinear Problem Circular Arc boundary natural boundary reduction Error Estimates

natural boundary Element Method for ParabolicEquations in an Unbounded Domain

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mathematical Research and Exposition 2002年第2期22卷 177-188页

作者：朱昌杰杜其奎淮北煤炭师范学院安徽淮北235000 南京师范大学数学与计算机科学学院江苏南京210097

In this paper we introduce an implementation for the efficient numericalsolution of exterior initial boundary value problem for parabolic equation. The problemis reformulated as an equivalent one on a boundary T using natural boundary *** governing equation is first discretized in time, leading to a time-stepping scheme,where an exterior elliptic problem has to be solved in each time step. By Fourier ex-pansion, we derive a natural integral equation of the elliptic problem related to timestep and Poisson integral integral formula over exterior circular domain. Finite elementdiscretization of the natural integral equation is employed to solve this problem. Thecomputational aspects of this method are discussed. Numerical results are presented toillustrate feasibility and efficiency of our method.

关键词： parabolic problem natural boundary reduction exterior problem numer-ical implementation finite element.