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AN INVERSE EIGENVALUE PROBLEM FOR JACOBI MATRICES

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Journal of Computational mathematics 2003年第5期21卷 569-584页

作者： Er-xiong Jiang (department of mathematics, shanghai university, shanghai 200436, china) department of mathematics Shanghai University 上海 200436

Let T1,n be an n x n unreduced symmetric tridiagonal matrix with eigenvaluesand is an (n - 1) x (n - 1) submatrix by deleting the kth row and kth column, k = 1, 2,be the eigenvalues of T1,k andbe the eigenvalues of Tk+1,nA new inverse eigenvalues problem has put forward as follows: How do we construct anunreduced symmetric tridiagonal matrix T1,n, if we only know the spectral data: theeigenvalues of T1,n, the eigenvalues of Ti,k-1 and the eigenvalues of Tk+1,n?Namely if we only know the data: A1, A2, An,how do we find the matrix T1,n? A necessary and sufficient condition and an algorithm ofsolving such problem, are given in this paper.

关键词： Symmetric tridiagonal matrix Jacobi matrix Eigenvalue problem Inverse eigenvalue problem.

An improvement in stability of delay difference systems

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Chinese Science Bulletin 1998年第7期43卷 544-547页

作者： ZHANG Shunian department of Applied mathematics, shanghai Jiaotong university, shanghai 200240, china department of Applied mathematics Shanghai Jiaotong University Shanghai China

A new result on the stability of delay difference equations is established, in which a kind of weighted norm for x is adopted in order to estimate the upper bound of Liapunov functional.

关键词： delay difference systems uniform asymptotic stability in terms of two measures Liapunov functionals.

The　θ－Methods　in　Numerical　Solution　of　Systems　of　Differential　Equations　with　Two　Delay　Terms

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Journal of Systems Engineering and Electronics 1994年第3期5卷 32-40页

作者： Tian Hongjiong & Kuang Jiaoxun (department of mathematics, shanghai Normal university, shanghai 200234, china) department of mathematics Shanghai Normal University Shanghai 200234 China

This paper deals with the numerical solution of initial value problems for systems of differential equations with two delay terms. We investigate the stability of adaptations of the θ-methods in the numerical solution of test equations u'(t) = a 11 u(t) + a12v(t) + b11 u(t - τ1) + b12v(t-τ2,v'(t) = a21 u(t) + a22 v(t) + b21 u(t -τ1,) + b22 v(t -τ2), t>0,with initial conditionsu(t)=u0(t),v(t) =v0(t), t≤*** aij, bij∈C, τj >0, i,j = 1,2,, and u0(t), v0(t)are continuous and complex valued. Sufficient conditions for the asymptotic stability of test equation are derived. Furthermore, with respect to an appropriate definition of stability for the numerical method, it is proved that the linear θ-method is stable if and only if 1/2≤θ≤1 and the one-leg θ-method is stable if and only if θ= 1.

关键词： Delay differential equations Numerical solution θ-methods Asymptotic stability Schur polynomial.

Global existence of smooth solutions to two-dimensional compressible isentropic Euler equations for Chaplygin gases

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Science china mathematics 2010年第3期53卷 719-738页

作者： KONG DeXing 1 , LIU KeFeng 2 & WANG YuZhu 3, 1 department of mathematics, Zhejiang university, Hangzhou 310027, china 2 department of mathematics, university of California at Los Angeles, CA 90095, USA 3.department of mathematics, shanghai Jiao Tong university, shanghai 200248, china 1. department of mathematics Zhejiang University Hangzhou 310027 China2. Department of Mathematics University of California at Los Angeles Los Angeles CA 90095 USA3. Department of Mathematics Shanghai Jiao Tong University Shanghai 200248 China

In this paper we investigate the two-dimensional compressible isentropic Euler equations for Chaplygin gases. Under the assumption that the initial data is close to a constant state and the vorticity of the initial velocity vanishes, we prove the global existence of the smooth solution to the Cauchy problem for twodimensional flow of Chaplygin gases.

关键词： Chaplygin gases compressible Euler equations irrotational flow null condition Cauchy problem smooth solution

ON THE APPROXIMATELY SIMILARITY OF OPERATORS

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Chinese Annals of mathematics,Series B 1998年第4期19卷 465-472页

作者： WEI GUOQIANG (department of mathematics, East china Normal university, shanghai 200062, china.) E china Normal Univ Dept Math Shanghai 200062 Peoples R China

The author shows that a rank-preserving *-isorporphism between separable C*-algebras with unity is approximately equivalent to the identity representation. Some applications are made for approximately similarity of n-... 详细信息

关键词： C*-algebra Rank-preserving *-isomorphism Approximately equevalent,Approximately similar n-tuples of operators

SEMI-DEFINITE RELAXATION ALGORITHM FOR SINGLE MACHINE SCHEDULING WITH CONTROLLABLE PROCESSING TIMES

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Chinese Annals of mathematics,Series B 2005年第1期26卷 153-158页

作者： CHENFENG ZHANGLIANSHENG departmentofmathematics ShanghaiUniversityShanghai200436China／／DepartmentofIndustrialEngineeringandManagementShanghaiJiaotongUniversityShanghai200030China. departmentofmathematics ShanghaiUniversityShanghai200436China

The authors present a semi-definite relaxation algorithm for the scheduling problem with controllable times on a single machine. Their approach shows how to relate this problem with the maximum vertex-cover problem with kernel constraints (MKVC).The established relationship enables to transfer the approximate solutions of MKVCinto the approximate solutions for the scheduling problem. Then, they show how to obtain an integer approximate solution for MKVC based on the semi-definite relaxation and randomized rounding technique.

关键词： Scheduling with controllable times Semi-definite programming Approximation algorithm

STABILITY OF IMPULSIVE LINEAR HYBRID SYSTEMS WITH TIME DELAY

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Journal of Systems Science & Complexity 2010年第4期23卷 738-747页

作者： Yu ZHANG·Jitao SUN department of mathematics,Tongji university,shanghai 200092,china. JitaoSUN department of mathematics Tongji University

This paper investigates the stability of impulsive linear hybrid systems with time *** a number of delay-independent/delay-dependent stability criteria are obtained by using Lyapunovfunctions or Lyapunov *** examples ... 详细信息

关键词： Impulsive linear hybrid system Lyapunov function Lyapunov functional time delay.

A KIND OF IMPLICIT ITERATIVE METHODS FOR ILL-POSEDOPERATOR EQUATIONS

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Journal of Computational mathematics 1999年第3期17卷 275-284页

作者： Guo-qiang He Lin-clan Liu(department of mathematics, shanghai university, Jiading Campus, shanghai 201800, china) 上海大学数学系上海

In this paper we propose a kind of implicit iterative methods for solving ill-posed operator equations and discuss the properties of the methods in the case that the control parameter is fixed. The theoretical results show that the new methods have certain important features and can overcome some disadvantages of Tikhonov-type regularization and explicit iterative methods. Numerical examples are also given in the paper, which coincide well with theoretical results.

关键词： ill-posed equation implicit iterative method control parameter discrepamcy principle optimal convergence rate

REGULARITY RESULTS FOR SOME QUASI-LINEAR ELLIPTIC SYSTEMS INVOLVING CRITICAL EXPONENTS

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Chinese Annals of mathematics,Series B 2005年第1期26卷 119-126页

作者： HUYEXIN LIJUAN departmentofmathematics ShanghaiJiaotongUniversityShanghai200240China departmentofmathematics ShanghaiJiaotongUniversityShanghai200240China.

The authors show the regularity of weak solutions for some typical quasi-linear elliptic systems governed by two p-Laplacian operators. The weak solutions of the following problem with lack of compactness are proved t... 详细信息

关键词： Elliptic equation system p-Laplacian operator Critical Sobolev exponent Regularity