检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2004年第5期47卷 659-674页

作者： SHI Peihu & WANG Mingxindepartment of mathematics, southeast university, nanjing 210018, china department of mathematics, Xuzhou Normal university, Xuzhou 221116, china 1. department of mathematics Southeast University 210018 Nanjing China 2. department of mathematics Xuzhou Normal University 221116 Xuzhou China

This paper is devoted to study the classification of self-similar solutions to the quasilinear parabolic equations with nonlinear gradient termsu t = Δ(u m) - uq∣Δu∣ p withm ≥ 1,p,q > 0 andp +q >m. Form = 1, it is shown that the very singular self-similar solution exists if and only ifnq + (n +1)p 2, and in case of existence, such solution is unique. Form > 1, it is shown that very singular self-similar solutions exist if and only if 1 2 andnq + (n + 1)p 2 +mn, and such solutions have compact support if they exist. Moreover, the interface relation is obtained.

关键词： quasilinear parabolic equations, self-similar solutions, very singular solution, classification.

The Regularity of Munn Rings and Semigroup Rings

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 1995年第1期11卷 53-61页

作者： Li Fang department of mathematics and Mechanics southeast university nanjing,210018 china southeast university

In this paper,the author studies the regularity of Munn rings and completely 0- simple semigroup *** either(i)R is a ring with identity and I and A are infinite,or(ii) R is a strong IBN and fully Dedekind-finite ring with identity and either I or A is finite,in Section 2,the regularity of the Munn ring M(R;I,A;P)is characterized;in Section 3,for a completely 0-simple semigroup S= M°(G;I,A;P),the regularity of RS is ***,the author shows that for a locally finite monoid S and a ring R with identity,RS is a strong IBN ring if and only if R is so;RS is fully Dedekind-finite if and only if R is so.

关键词： The Regularity of Munn Rings and Semigroup Rings over IBN ABA Math

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

MULTIVALUED PERTURBATION TO NONLINEAR DIFFERENTIAL INCLUSIONS WITH MEMORY IN BANACH SPACES

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 1996年第2期17卷 237-244页

作者： XUEXINGMEI SONGGUOZHU departmentofMathemtics＆Mechanics SoutheastUniversityNanjing210018China. departmentofmathematics NanjingUniversityNanjing210008China.

The authors give the existence results to the nonlinear differential inclusion u'(t) ∈ Au(t) +F(t,ut), where A is a ganerator of equicontinuous semigroup and F is multivalued.

关键词： Differential inclusion with memory Equicontimuous semigroup Housdorff measure Kamke function

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, southeast university, 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

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... 详细信息

关键词： parabolic southeast instead conduction derivative

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 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 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 35K15 35K65

A MODIFIED BISECTION SIMPLEX METHOD FOR LINEAR PROGRAMMING

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 1996年第3期14卷 249-255页

作者： P.Q. Pan(department of mathematics and Mechanics, southeast university, nanjing china) southeast UNIV DEPT MATH & MECHNANJINGPEOPLES R CHINA

In this paper, a modification of the bisection simplex method([7]) is made for more general purpose use. Organized in an alternative simpler form, the modified version exploits information of the optimal value, as does the original bisection method, but no bracket on the optimal value is needed as part of input; in stead, it only requires provision of an estimate b(0) of the optimal value and an estimate of the error bound of b(0) (it is not sensitive to these values though). Moreover, a new, ratio-test-free pivoting rule is proposed, significantly reducing computational cost at each iteration. Our numerical experiments show that the method is very promising, at least for solving linear programming problems of such sizes as those tested.

关键词： Algorithms Simplex method Information economics Method of bisection Error bounds Optimal solutions

Asymptotic bound on binary self-orthogonal codes

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2009年第4期52卷 631-638页

作者： DING Yang department of mathematics, southeast university, nanjing 210096, china 1. department of mathematics Southeast University Nanjing 210096 China

We present two constructions for binary self-orthogonal codes. It turns out that our constructions yield a constructive bound on binary self-orthogonal codes. In particular, when the in-formation rate R = 1/2, by our constructive lower bound, the relative minimum distance δ≈ 0.0595 (for GV bound, δ≈ 0.110). Moreover, we have proved that the binary self-orthogonal codes asymptotically achieve the Gilbert-Varshamov bound.

关键词： algebraic geometry codes concatenated codes Gilbert-Varshamov bound Reed-Muller codes self-dual basis self-orthogonal codes 11T71