检索结果-南通市图书馆

A NEW PERTURBATION SIMPLEX ALGORITHM FOR LINEARPROGRAMMING

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 1999年第3期17卷 233-242页

作者： Ping-qi Pan(department of applied mathematics,{3., Naming 210096, China) 东南大学应用数学系江苏南京

In this paper, we first propose a perturbation procedure for achieving dual feasibility, which starts with any basis without introducing artificial variables. This procedure and the dual simplex method are then incorporated into a general purpose algorithm; then, a modification of it using a perturbation technique is made in order to handle highly degenerate problems efficiently. Some interesting theoretical results are presented. Nmerical results obtained are reported, which are very encouraging though still preliminary.

关键词： linear programming simplex method perturbation dual feasibility

PRIMAL PERTURBATION SIMPLEX ALGORITHMS FOR LINEAR PROGRAMMING

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 587-596页

作者： Ping-qi Pan (department of applied mathematics,{3., Nanjing 210096, China.) 东南大学江苏南京 210096

In this paper, we propose two new perturbation simplex variants. Solving linear programming problems without introducing artificial variables, each of the two uses the dual pivot rule to achieve primal feasibility, and then the primal pivot rule to achieve optimality. The second algorithm, a modification of the first, is designed to handle highly degenerate problems more efficiently. Some interesting results concerning merit of the perturbation are established. Numerical results from preliminary tests are also reported. [ABSTRACT FROM AUTHOR]

关键词： linear programming perturbation primal simplex algorithm partially revised tableau

On the periodic solutions of a type of differential-iterative equations

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第3期43卷 204-206页

作者： GE Weigao 1, LIU Zhengrong 2 and YU Yuanhong 3.1. department of applied mathematics, Beijing Institute of Technology, Beijing 100081, China 2. department of mathematics, Yunnan university, Kunming 650091, China 3. Institute of applied mathematics, C department of applied mathematics Beijing Institute of Technology Beijing China department of mathematics Yunnan University Kunming China Institute of applied mathematics Chinese Academy of Sciences Beijing China

Sufficient conditions for the existence of periodic solutions to a type of nonautonomous differential_iterative equations are given.

关键词： differential_iterative equation periodic solution fixed point.

Global existence and blow-up of solutions to a parabolic system with nonlocal sources and boundaries

在线全文

学校读者我要写书评

暂无评论

Science China mathematics 2007年第9期50卷 1251-1266页

作者： Ling-hua KONG~(1+) Ming-xin WANG~(2,3. 1 department of applied mathematics,Dalian {3. of Technology,Dalian 116024,China 2 department of mathematics,southeast {3.,Nanjing 210018,China 3.department of mathematics,Xuzhou Normal {3.,Xuzhou 221116,China 1. department of applied mathematics Dalian University of Technology Dalian 116024 China 2. department of mathematics Southeast University Nanjing 210018 China 3. department of mathematics Xuzhou Normal University Xuzhou 221116 China

This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super-and sub-solution techniques, we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively, and then give the necessary and sufficient conditions that two components u and ν blow up simultaneously. Finally, the uniform blow-up profiles in the interior are presented.

关键词： parabolic system nonlocal sources nonlocal boundary conditions blow-up set simultaneous blow-up uniform blow-up profile 3.K15 3.K65

Boundary Layer Theory and the Zero-Viscosity Limit of the Navier-Stokes Equation

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2000年第2期16卷 207-218页

作者： Weinan E department of mathematics and Program in applied and Computational mathematics,Princeton university,USA department of mathematics and Program in applied and Computational mathematics Princeton University Princeton USA

A central problem in the mathematical analysis of fluid dynamics is the asymptotic limit of the fluid flow as viscosity goes to *** is particularly important when boundaries are present since vorticitv is typically generated at the boundary as a result of boundary layer *** boundary laver theory,developed by Prandtl about a hundred years ago,has become a standard tool in addressing these *** at the mathematical level,there is still a lack of fundamental understanding of these questions and the validity of the boundary layer *** this article,we review recent progresses on the analysis of Prandtl’s equation and the related issue of the zero-viscosity limit for the solutions of the Navier-Stokes *** also discuss some directions where progress is expected in the near future.

关键词： Boundary layer Blow-up Zero-viscosity limit Prandtl’s equation

SERIES REPRESENTATION OF DAUBECHIES' WAVELETS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 1997年第1期15卷 81-96页

作者： X.G. Lu (department of applied mathematics, Tsinghua {3., Beijing, China) 清华大学应用数学系北京

This paper gives a kind of series represeotation of the scaling functions φNand the associated wavelets . constructed by Daubechies. Based on Poission sununation formula, the functions gh. φN(x+N-1), φN (x+N),'''' φN (x+2N-2)(Ox 1) are linearly represented by φN(x), φN(x + 1),''', φN(x + 2N - 2) and some polynomials of order less than N, and φ0(x):= (φN (x), φN (x + 1),''', φN (x + N -2))t is translated into a solution of a nonhomogeneous vectorvalued functional equationwhere A0, A1 are (N - 1) x (N - 1)-dimensional matrices, the components of P0(x), P1 (x) are polynomials of order less than N. By iteration, .φ0(x) is eventualy represented as an (N - 1)-dimensional vector series with vector norm where and

关键词： Pro ER Math Si WAVELETS SERIES REPRESENTATION OF DAUBECHIES

Linearization Ill-Posedness for 2.5-D Ware Equation Inversion Model

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2002年第2期18卷 219-230页

作者： Ji-jun Liudepartment of mathematics, Nanjing Normal university, Nanjing 210097, China & department of applied mathematics, southeast university, Nanjing 210018, China department of mathematics Nanjing Normal University Nanjing China department of applied mathematics Southeast University Nanjing China

For the weakly inhomogeneous acoustic medium in Ω={(x,y,z):z>0}, we consider the inverse problem of determining the density function p(x,y). The inversion input for our inverse problem is the wave field given on a line. We get an integral equation for the 2-D density perturbation from the linearization. By virtue of the integral transform, we prove the uniqueness and the instability of the solution to the integral equation. The degree of ill-posedness for this problem is also given.

关键词： Linearization inversion integral geometry ill-posedness

A LINEARIZED DIFFERENCE SCHEME FOR THE KURAMOTO-TSUZUKI EQUATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 1996年第1期14卷 1-7页

作者： Z.Z. Sun(department of mathematics and Mechanics, southeast university, Nanjing, China) southeast UNIV DEPT MATH & MECHNANJINGPEOPLES R CHINA

In this paper, a linearized three-level difference scheme is derived for the mixed boundary value problem of Kuramoto-Tsuzuki equation, which can be solved by double-sweep method. It is proved that the scheme is uniqu...

关键词： parabolic southeast instead conduction derivative

CMC surfaces in the hyperbolic 3.space

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第7期43卷 547-550页

作者： YU Zuhuan 1, 2 and LI Zhenqi 1, 3.1. Institute of mathematics, Fudan university, Shanghai 20043., China 2. department of mathematics,Sichuan Union university, Chengdu 610064, China 3. department of mathematics, Nanchang university, Nanchang 3. nstitute of Mathemalics Fudan University Shanghai China department of mathematics Sichuan Union University Chengdu China department of mathematics Nanchang University Nanchang China

CMC-H surfaces satisfying H≥1 are studied. It is proved that these surfaces possess a natural representation which is a generalization of the Bryant’s result.

关键词： hyperbolic space CMC surface Weierstrass representation.