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Variable Coefficients (variable + coefficient)

Distribution by Scientific Domains
Mathematics and Statistics66%
Engineering22%

Selected Abstracts

An interactive fuzzy satisficing method for multiobjective stochastic linear programming problems using chance constrained conditions

JOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 3 2002
Masatoshi Sakawa
Abstract Two major approaches to deal with randomness or ambiguity involved in mathematical programming problems have been developed. They are stochastic programming approaches and fuzzy programming approaches. In this paper, we focus on multiobjective linear programming problems with random variable coefficients in objective functions and/or constraints. Using chance constrained programming techniques, the stochastic programming problems are transformed into deterministic ones. As a fusion of stochastic approaches and fuzzy ones, after determining the fuzzy goals of the decision maker, interactive fuzzy satisficing methods to derive a satisficing solution for the decision maker by updating the reference membership levels is presented. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Approximate boundary controllability for the system of linear elasticity

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 17 2004
Andrzej
Abstract The approximate controllability for variable coefficients, isotropic, evolution elasticity system is considered. The appropriate unique continuation theorem for solutions of the system is stated. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Local energy decay for a class of hyperbolic equations with constant coefficients near infinity

MATHEMATISCHE NACHRICHTEN, Issue 5 2010
Shintaro Aikawa
Abstract A uniform local energy decay result is derived to a compactly perturbed hyperbolic equation with spatial vari¬able coefficients. We shall deal with this equation in an N -dimensional exterior domain with a star-shaped complement. Our advantage is that we do not assume any compactness of the support on the initial data and the equation includes anisotropic variable coefficients {ai(x): i = 1, 2, ,, N }, which are not necessarily equal to each other (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Convergence of adaptive edge finite element methods for H(curl)-elliptic problems

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 2-3 2010
Liuqiang Zhong
Abstract The standard adaptive edge finite element method (AEFEM), using first/second family Nédélec edge elements with any order, for the three-dimensional H(curl)-elliptic problems with variable coefficients is shown to be convergent for the sum of the energy error and the scaled error estimator. The special treatment of the data oscillation and the interior node property are removed from the proof. Numerical experiments indicate that the adaptive meshes and the associated numerical complexity are quasi-optimal. Copyright © 2010 John Wiley & Sons, Ltd. [source]

The homotopy analysis method for solving higher dimensional initial boundary value problems of variable coefficients

NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS, Issue 5 2010
H. Jafari
Abstract In this article, higher dimensional initial boundary value problems of variable coefficients are solved by means of an analytic technique, namely the Homotopy analysis method (HAM). Comparisons are made between the Adomian decomposition method (ADM), the exact solution and the homotopy analysis method. The results reveal that the proposed method is very effective and simple. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010 [source]

An unconditionally stable and O(,2 + h4) order L, convergent difference scheme for linear parabolic equations with variable coefficients

NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS, Issue 6 2001
Zhi-Zhong Sun
Abstract M. K. Jain, R. K. Jain, and R. K. Mohanty presented a finite difference scheme of O(,2 + ,h2 + h4) for solving the one-dimensional quasilinear parabolic partial differential equation, uxx = f(x, t, u, ut, ux), with Dirichlet boundary conditions. The method, when applied to a linear constant coefficient case, was shown to be unconditionally stable by the Von Neumann method. In this article, we prove that the method, when applied to a linear variable coefficient case, is unconditionally stable and convergent with the convergence order O(,2 + h4) in the L, -norm. In addition, we obtain an asymptotic expansion of the difference solution, with which we obtain an O(,4 + ,2h4 + h6) order accuracy approximation after extrapolation. And last, we point out that the analysis method in this article is efficacious for complex equations. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17:619,631, 2001 [source]

New Zonal, Spectral Solutions for the Navier-Stokes Layer and Their Applications

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003
A. Nastase Prof. Dr.-Ing., Dr. Math.
New zonal, spectral forms for the axial, lateral and vertical velocity's components, density function and absolute temperature inside of compressible three-dimensional Navier-Stokes layer (NSL) over flattened, flying configurations (FC), are here proposed. The inviscid flow over the FC, obtained after the solidification of the NSL, is here used as outer flow. If the spectral forms of the velocity's components are introduced in the partial differential equations of the NSL and the collocation method is used, the spectral coefficients are obtained by the iterative solving of an equivalent quadratical algebraic system with slightly variable coefficients. [source]

Exact controllability of wave equations with variable coefficients coupled in parallel,,

ASIAN JOURNAL OF CONTROL, Issue 5 2010
Jieqiong Wu
Abstract In this paper, we investigate exact controllability for coupled wave equations which have variable coefficients principal part. Observability inequality is obtained by using Riemannian geometry method and Carleman estimates. Furthermore, the exact controllability result is established with Dirichlet boundary controls when T>T0, where the lower bound T0 for the control time T is different from that obtained in the constant coefficient principal part case. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]