检索结果-南通市图书馆

A NONMONOTONE TRUST REGION ALGORITHM FOR NONLINEAR OPTIMIZATION SUBJECT TO GENERAL CONSTRAINTS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 2003年第2期21卷 237-246页

作者： Hongchao Zhang+ (department of mathematics, university of florida, Gainesville, fl, usa 32611 ) department of mathematics University of Florida 美国 Gainesville

In this paper we present a nonmonotone trust region algorithm for general nonlinear constrained optimization problems. The main idea of this paper is to combine Yuan's technique[1] with a nonmonotone method similar to Ke and Han [2]. This new algorithm may not only keep the robust properties of the algorithm given by Yuan, but also have some advantages led by the nonmonotone technique. Under very mild conditions, global convergence for the algorithm is given. Numerical experiments demonstrate the efficiency of the algorithm.

关键词： Nonlinear optimization Nonmonotone algorithm Trust region General con-straintss

FOUR STEP SCHEME FOR GENERAL MARKOVIAN FORWARD-BACKWARD SDES

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2010年第3期23卷 546-571页

作者： Jin MA Jiongmin YONG Yanhong ZHAO department of mathematics University of Southern California Los Angeles CA 90089 USA department of mathematics University of Central Florida Orlando FL 32816 USA department of mathematics Purdue University West Lafayette IN 47907 USA

This paper studies a class of forward-backward stochastic differential equations (FBSDE)in a general Markovian *** forward SDE represents a large class of strong Markov semimartingales,and the backward generator requires only mild regularity *** authors showthat the Four Step Scheme introduced by Ma,et al.(1994) is still effective in this ***,the authors show that the adapted solution of the FBSDE exists and is unique over any prescribedtime duration;and the backward components can be determined explicitly by the forward componentvia the classical solution to a system of parabolic integro-partial differential *** importantconsequence the authors would like to draw from this fact is that,contrary to the general belief,in aMarkovian set-up the martingale representation theorem is no longer the reason for the well-posednessof the FBSDE,but rather a consequence of the existence of the solution of the decoupling integralpartialdifferential ***,the authors briefly discuss the possibility of reducing the regularityrequirements of the coefficients by using a scheme proposed by *** (2002) to the current case.

关键词： Forward-backward stochastic differential equations Four Step Scheme parabolic integropartial differential equation strong Markov semi-martingales.

On interpolation for Hormander’s algebras

在线全文

学校读者我要写书评

暂无评论

Science China mathematics 2010年第3期53卷 763-770页

作者： LI Bao Qin department of mathematics, florida International university, Miami, fl 33199, usa 1. department of mathematics Florida International University Miami FL 33199 USA

We discuss some recent results on interpolation problems for weighted Hrmander’s algebras of holomorphic functions in several complex variables, and also give a sharp estimate on counting functions of interpolating... 详细信息

关键词： weight pseudoconvex set Hrmander’s algebra interpolating variety plurisubharmonic function holomorphic function entire function

Approximating Stationary Statistical Properties

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 2009年第6期30卷 831-844页

作者： Xiaoming WANG Dedicated to Professor Andrew Majda on the Occasion of his 60th Birthday with Admiration and Friendship）

It is well-known that physical laws for large chaotic dynamical systems are revealed *** times these statistical properties of the system must be approximated *** main contribution of this manuscript is to provide simple and natural criterions on numerical methods (temporal and spatial discretization) that are able to capture the stationary statistical properties of the underlying dissipative chaotic dynamical systems *** result on temporal approximation is a recent finding of the author,and the result on spatial approximation is a new *** to the infinite Prandtl number model for convection and the barotropic quasi-geostrophic model are also discussed.

关键词： Stationary statistical property Invariant measure Global attractor Dissipative system Time discretization Spatial discretisation Uniformly dissipative scheme Infinite Prandtl number model for convection Barotropic quasi-geostrophic equations

The realization and structure of complete Lie algebras whose nilpotent radicals are Heisenberg algebras

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第5期43卷 383-385页

作者： JIANG Cuibo 1 and MENG Daoji 2 1.department of mathematics,Yantai Teachers university, Yantai 264025, China 2.department of mathematics,Nankai university,Tianjin 300071, China. department of mathematics Yantai Teachers University Yantai China department of mathematics Nankai University Tianjin China

The realization and structure of complete Lie algebras whose nilpotent radicals are Heisenberg algebras over the complex field C are given.

关键词： complete Lie algebra Heisenberg algebra nilpotent radical.

flatness of CR submanifolds in a sphere

在线全文

学校读者我要写书评

暂无评论

Science China mathematics 2010年第3期53卷 701-718页

作者： JI ShanYu 1, & YUAN Yuan 2 1 department of mathematics, university of Houston, Houston, TX 77204, usa 2.department of mathematics, Rutgers university, Piscataway, NJ 08854, usa 1. department of mathematics University of Houston Houston TX 77204 USA2. Department of Mathematics Rutgers University Piscataway NJ 08854 USA

In Euclidean geometry, for a real submanifold M in E n+a , M is a piece of E n if and only if its second fundamental form is identically zero. In projective geometry, for a complex submanifold M in CP n+a , M is a piece of CP n if and only if its projective second fundamental form is identically zero. In CR geometry, we prove the CR analogue of this fact in this paper.

关键词： CR submanifolds sphere CR second fundamental form proper holomorphic mappings between balls

NONOSCILLATION RESULTS FOR A CLASS OF THIRD ORDER NONLINEAR DIFFERENTIAL EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and Mechanics(English Edition) 2002年第10期23卷 1170-1175页

作者： Pakize Temtek 1, Aydn Tiryaki 2 (1 department of mathematics, Faculty of Arts and Science, Erciyes university, 38039, Kayseri, Turkey 2.department of mathematics, Faculty of Arts and Science, Gazi university, Teknikokullar 06500 Ankara, Turke department of mathematics Faculty of Arts and Science Erciyes University 38039 Kayseri Turkey department of mathematics Faculty of Arts and Science Gazi University Teknikokullar 06500 Ankara Turkey

Sufficient conditions for the nonoscillatory solutions of a class of third order nonlinear differential equations are presented. The results obtained generalize some criteria given by Parhi. In some special cases, som... 详细信息

关键词： differential equation nonlinear nonoscillatory solution Parhi criteria

EXISTENCE AND NONEXISTENCE OF GLOBAL POSITIVE SOLUTIONS FOR DEGENERATE PARABOLIC EQUATIONS IN EXTERIOR DOMAINS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2010年第3期30卷 713-725页

作者：曾宪忠刘振海 department of mathematics and Computational Science Hunan University of Science and Technology department of mathematics Central South University

This article deals with the degenerate parabolic equations in exterior domains and with inhomogeneous Dirichlet boundary conditions. We obtain that pc = （σ ＋ m ）n / （ n-σ- 2 ） is its critical exponent provided max{-1, [ （1- m ）n- 2] / （ n ＋ l ） } 〈 σ 〈 n- 2. This critical exponent is not the same as that for the corresponding equations with the boundary value 0, but is more closely tied to the critical exponent of the elliptic type degenerate equations. Futhermore, we demonstrate that if max（1, σ ＋ m）〈 p 〈 pc, then every positive solution of the equations blows up in finite time; whereas for p 〉 pc, the equations admit global positive solutions for some boundary values and initial data. Meantime, we also demonstrate that its positive solutions blow up in finite time provided n〈σ＋2.

关键词： Degenerate parabolic equations exterior domains -inhomogeneous dirichlet boundary conditions critical exponent blow-up global existence

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