检索结果-南通市图书馆

Science china Mathematics 2009年第7期52卷 1579-1588页

作者： MENG QingXin1,2 1 Department of mathematical Sciences,Huzhou university,Zhejiang 313000,china 2 institute of Mathematics,fudan university,shanghai 200433,china Department of mathematical Sciences Huzhou University Zhejiang China institute of Mathematics Fudan University Shanghai China

The paper is concerned with a stochastic optimal control problem in which the controlled system is described by a fully coupled nonlinear forward-backward stochastic differential equation driven by a Brownian *** is required that all admissible control processes are adapted to a given subfiltration of the filtration generated by the underlying Brownian *** this type of partial information control,one sufficient(a verification theorem) and one necessary conditions of optimality are *** control domain need to be convex and the forward diffusion coefficient of the system can contain the control variable.

关键词： maximum principle stochastic optimal control partial information 93E20 60H10 60H30

A remark on p- harmonic heat flows

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第6期42卷 441-444页

作者： LIU Xiangaoinstitute of Mathematics, fudan university, shanghai 200433, china institute of Mathematics Fudan University Shanghai China

IN this note we prove the existence of the global weak solutions of p-harmonic heat flows, in particular 11 (see Lemma 2), and it is in itself a significance.

关键词： harmonic map heat flows existence.

BOUNDARY REGULARITY FOR WEAK HEAT FLOWS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2002年第1期23卷 119-136页

作者： LIU XIANGAO institute Mathematics, fudan university, shanghai 200433, china. E-mail: xgliuk@*** institute Mathematics Fudan University Shanghai 200433 China

The partial regularity of the weak heat flow of harmonic maps from a Riemannian manifold Al with boundary into general compact Riemannian manifold N without boundary is consid-ered. It is shown that the singular set Sing(u) of the weak heat flow satisfies H(Sing(u)) 0, with is = dimensionM. Here is Hausdorff measure with respect to parabolic metric ρ(x,t),(y,s)=max{|x-y|, }.

关键词： weak heat flow of harmonic maps Hardy-BMO duality partial regularity

TENSOR PRODUCTS OF JACOBSON RADICALS IN NEST ALGEBRAS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2003年第3期24卷 323-330页

作者： DONG ZHE Departinent of Mathematics, Zhejiang university, Hangzhou 310027, china. institute of Mathematics, fudan university, shanghai 200433, china. Department of Mathematics Zhejiang University Hangzhou 310027 China institute of Mathematics Fudan University Shanghai 200433 China

This paper studies the tensor product RN RM of Jacobson radicals in nest algebras, and obtains that RN RM = {T∈B(H1 H2) : T(N M)(?)N_ M_, N∈N,M∈M}; and based on the characterization of rank-one operators in RN RM,i... 详细信息

关键词： Jacobson radical Tensor product Nest algebra

SIMULATION OF FLUID-SOLID INTERACTION ON WATER DITCHING OF AN AIRPLANE BY ALE METHOD

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第5期23卷 637-642页

作者： HUA Cheng FANG Chao CHENG Jin Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China School of mathematical Sciences Fudan University Shanghai 200433 China

Ditching is considered as one of the important aspects of safety performances of airplanes. It is related primarily with the fluid-solid interaction, whose studies mainly depend on experiments at the present time. Numerical and analytical methods for fluid-solid interaction by using 3-D full scale airplane＇s model will reduce the dependence on the expensive model tests. Numerical studies can be used to estimate the safety of ditching and provide a reference for the crashworthiness design. This article proposes a 3-D dynamical structural model after the real shape of an airplane and an Arbitrary Lagrange-Euler （ALE） fluid-field model, to simulate the fluid-solid interactions caused by low speed ditching. The simulation is based on interaction computational methods, within LS-DYNA nonlinear finite-element code. The results of pressure distributions and accelerating time histories of the airplane＇s subfloor are discussed in the context of the safety of ditching, and the simulation results and the analytical methods are verified.

关键词： ditching fluid structure interaction Arbitrary Lagrange-Euler (ALE) finite element method

Determination of environmental pollutants bythermal lens method

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 1995年第2期7卷 163-166页

作者： Zhang Yue Deng Guohong Li Changlin(Environmental Science institute, fudan university , shanghai 200433 , china) fudan Univ Envmlt Sci Inst Shanghai China China

ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆｅｎｖｉｒｏｎｍｅｎｔａｌｐｏｌｌｕｔａｎｔｓｂｙｔｈｅｒｍａｌｌｅｎｓｍｅｔｈｏｄＺｈａｎｇＹｕｅ；ＤｅｎｇＧｕｏｈｏｎｇ；ＬｉＣｈａｎｇｌｉｎ（ＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃ... 详细信息

ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆｅｎｖｉｒｏｎｍｅｎｔａｌｐｏｌｌｕｔａｎｔｓｂｙｔｈｅｒｍａｌｌｅｎｓｍｅｔｈｏｄＺｈａｎｇＹｕｅ；ＤｅｎｇＧｕｏｈｏｎｇ；ＬｉＣｈａｎｇｌｉｎ（ＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｉｎｓｔｉｔｕｔｅ，ＦｕｄａｎＵ...

关键词： thermal lens : carbon disulfide anthracene benzophenone.

ALMOST GLOBAL EXISTENCE OF DIRICHLETINITIAL-BOUNDARY VALUE PROBLEM FORNONLINEAR ELASTODYNAMIC SYSTEMOUTSIDE A STAR-SHAPED DOMAIN

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2004年第4期25卷 433-454页

作者： XINJIE QINTIEHU instituteofMathematics FudanUniversityShanghai200433China DepartmentofMathematics FudanUniversityShanghai200433China

This paper deals with the mixed initial-boundary value problem of Dirichlet type for the nonlinear elastodynamic system outside a star-shaped domain. The almost global existence of solution with small initial data to ... 详细信息

关键词： Nonlinear elastodynamic system Exterior problem Almost global existence

Harmonic maps with potential from complete manifolds

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第21期43卷 1780-1786页

作者： CHEN Qun Mathematics Department, Central china Normal university, Wuhan 430079, china institute of Mathematics, fudan university, shanghai 200433, china Mathematics Department Central China Normal University Wuhan China institute of Mathematics Fudan University Shanghai China

Harmonic maps with potential from complete manifolds are considered. This is a new kind of maps more general than the usual harmonic maps relating to many interesting problems such as equilibrium system of ferromagnetic spin chain and Neumann motion. Aiming at the general properties, the author derives basic gradient estimates and then Liouville type results for these maps, which are interesting in constrast to those of the usual harmonic maps for the presence of potentials.

关键词： harmonic maps potential ferromagnetic chain gradient estimate.

Cocycle deformations, braided monoidal categories and quasitriangularity

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第6期44卷 510-513页

作者： CHEN HuixiangDepartment of Mathematics, Yangzhou university, Yangzhou 225002, china institute of Mathematics, fudan university, shanghai 200433, china Depnrtment of Mathematics Yangzhou University Yangzhou China institute of Mathematics Fudan University Shanghai China

Let A be a bialgebra, R ∈ A A be a strong “cocycle”. It will be shown that the monoidal category _Auhas a braided monoidal subcategory and several equivalent conditions for (A, R ) to be a quasitriangular bialgebra will be given. Furthermore, it will be shown that A contains a finite dimensional subbialgebra which is a quasitriangular Hopf algebra if R is a YB-operator.

关键词： strong cocycle Yang-Baxter operator braided monoidal category quasitriangular bialgebra.

Optimal variational principle for backward stochastic control systems associated with Lévy processes

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2012年第4期55卷 745-761页

作者： TANG MaoNing 1 & ZHANG Qi 2,1 Department of mathematical Sciences,Huzhou university,Huzhou 313000,china 2 School of mathematical Sciences,fudan university,shanghai 200433,china Department of mathematical Sciences Huzhou University Huzhou China School of mathematical Sciences Fudan University Shanghai China

The paper is concerned with optimal control of backward stochastic differentiM equation （BSDE） driven by Teugel＇s martingales and an independent multi-dimensional Brownian motion, where Teugel＇s martingales are a family of pairwise strongly orthonormal martingales associated with L6vy processes （see e.g., Nualart and Schoutens＇ paper in 2000）. We derive the necessary and sufficient conditions for the existence of the optimal control by means of convex variation methods and duality techniques. As an application, the optimal control problem of linear backward stochastic differential equation with a quadratic cost criteria （or backward linear-quadratic problem, or BLQ problem for short） is discussed and characterized by a stochastic Hamilton system.

关键词： stochastic control stochastic maximum principle Ldvy processes Teugel's martingales backwardstochastic differential equations