正定型超曲面上双曲闭特征的Maslov型指标的迭代公式

本文给出了R~(2n)中规范正定型超曲面上双曲闭特征的Maslov型指标的迭代公式.结果包含了凸超曲面和星形超曲面上已有的相应结论。     

超曲面上极小与极小凸点的分布

本文继续文［１］中的讨论,给出超曲面上点的极小与极小凸性更一般的判别方式,并且对超曲面上极小与极小凸点的分布有了更深刻的认识．作为应用,还证明了超曲面上一个极小点的传递性定理．     

R2n中P循环对称紧星型超曲面上P循环对称闭特征的多重性(英文)

设k≥2是正整数, ■,其中■是标准辛矩阵.在本文中,我们证明,对R²ⁿ中任意P循环对称紧星型超曲面Σ,Σ上至少存在一个P循环对称闭特征,其中n≥2;此外,我们给出星型超曲面上存在n个几何不同P循环对称闭特征的一个充分性条件.     

闭凸集上的一类非线性半变分不等式解的存在性

考虑一类定义在闭凸集上的非线性半变分不等式问题,通过运用闭凸集上的临界点理论、Clarke次微分性质以及非光滑紧性条件等,得到了这类半变分不等式解的存在性．     

三维空间型中闭曲面和测地球面的比较

本文建立关于三维空间型中的可定向闭曲面的某些公式.引入积分绝对平均曲率来描述可定向闭曲面的平均弯曲程度.在此意义上,可定向闭曲面可以与作为包含该闭曲面的凸的测地球的边界测地球面进行比较.这种比较能用于说明空间型自身的某些属性.     

三维空间型中闭曲面和测地球面的比较

本文建立关于三维空间型中的可定向闭曲面的某些公式.引入积分绝对平均曲率来描述可定向闭曲面的平均弯曲程度.在此意义上,可定向闭曲面可以与作为包含该闭曲面的凸的测地球的边界测地球面进行比较,这种比较能用于说明空间型自身的某些属性     

射影空间中代数曲线与超曲面的一些新的性质

发现了代数曲线的新的不变量一特征数,并得到了Pascal定理的不同于3次曲线的Cllasles定理和高次曲线中的Cayley-Bacharach定理等形式的高次推广.进一步研究了平面代数曲线的一些性质.通过定义m次Pascal超曲面,将Pascal定理推广到n维射影空间的m次超曲面中,证明了n-单纯形上的Pascal点位于一个m次Pascal超曲面的充要条件是其每个2维面上的Pascal点分别位于m次平面Pascal空间的一条代数曲线上.进一步,给出了一定条件下m次Pascal超曲面与m-1次Pascal超曲面之间的内在关系.     

de Sitter空间中的类空超曲面在平均曲率下的形变

本文考虑了deSitter空间中紧致的类空扭曲面在平均曲率下的形变,证明了如果初始曲面满足某一Pinching条件,超曲面将收敛到一个球面．这一结论类似于球面上超曲面的情形,而与欧氏空间中的超曲面完全不同．     

超曲面上极小与极小凸点的分布

本文继续文［1］中的讨论,给出超曲面上点的极小与极小凸性更一般的判别方式,并且对超曲面上极小与极小凸点的分布有了更深刻的认识.作为应用,还证明了超曲面上一个极小点的传递性定理.     

区间值映射的次可微性及其应用

本文讨论了区间值映射的次可微性问题,给出了次可微的概念及其基本性质,证明了区间值映射的次微分是空集或闭凸集;作为次微分的一种应用,讨论了区间值映射的次可微与其凸化区间值映射的次可微之间的关系,给出了一类区间值映射存在凸扩张区间值映射的充分条件。     

关于广义对数平均的一个不等式的加细

In this article,we show that the generalized logarithmic mean is strictly Schurconvex function for p＞2 and strictly Schur-concave function for P＜2 on R2+.And then we give a refinement of an inequality for the generalized logarithmic mean inequality using a simple majoricotion relation of the vector.     

锥—连续凸映射的严有效解连通性

本文介绍了严有效解的概念,并在[1]工作的基础上进一步研究了锥连续拟凸映射的严有效的连通性。     

Minimizing the sum of weighted completion times in a concurrent open shop

We study minimizing the sum of weighted completion times in a concurrent open shop. We give a primal-dual 2-approximation algorithm for this problem. We also show that several natural linear programming relaxations for this problem have an integrality gap of 2. Finally, we show that this problem is inapproximable within a factor strictly less than 6/5 if P≠NP, or strictly less than 4/3 if the Unique Games Conjecture also holds.     

Approximation Schemes for the Generalized Traveling Salesman Problem

A graph Γ is called a Deza graph if it is regular and the number of common neighbors of any two distinct vertices is one of two fixed values. A Deza graph is called a strictly Deza graph if it has diameter 2 and is not strongly regular. In 1992, Gardiner et al. proved that a strongly regular graph that contains a vertex with disconnected second neighborhood is a complete multipartite graph with parts of the same size greater than 2. In this paper, we study strictly Deza graphs with disconnected second neighborhoods of vertices. In Section 2, we prove that, if each vertex of a strictly Deza graph has disconnected second neighborhood, then the graph is either edge-regular or coedge-regular. In Sections 3 and 4, we consider strictly Deza graphs that contain at least one vertex with disconnected second neighborhood. In Section 3, we show that, if such a graph is edge-regular, then it is the s-coclique extension of a strongly regular graph with parameters (n, k, λ, μ), where s is an integer, s ≥ 2, and λ = μ. In Section 4, we show that, if such a graph is coedge-regular, then it is the 2-clique extension of a complete multipartite graph with parts of the same size greater than or equal to 3.     

Refined asymptotics for minimal graphs in the hyperbolic space

We study the boundary behaviors of solutions f to the Dirichlet problem for minimal graphs in the hyperbolic space with singular asymptotic boundaries and characterize the boundary behaviors of f at the points strictly located in the tangent cones at the singular points on the boundary. For n =2, we also obtain a refined estimate of f.     

On the Occurrence of "Vacuum States" for 2 $\times$ 2 Quasilinear Hyperbolic Conservation Laws

We show that the solution Lo the Cauchy problem of 2 × 2 nonlinear conservation laws, in general, may go out the strictly hyperbolic region of the system in a finite time, here the initial data are given in the strictly hyperbolic region. In other words, in general, we can't confine our attention to solve the Cauthy problem of 2 × 2 nonlinear consenvation laws in strictly hyperbolic type. However, we can expect that it may be solved under the additional conditions (A) and (b).     

Strictly semi-positive tensors and the boundedness of tensor complementarity problems

In this paper, we present the boundedness of solution set of tensor complementarity problem defined by a strictly semi-positive tensor. For strictly semi-positive tensor, we prove that all \(H^+(Z^+)\)-eigenvalues of each principal sub-tensor are positive. We define two new constants associated with \(H^+(Z^+)\)-eigenvalues of a strictly semi-positive tensor. With the help of these two constants, we establish upper bounds of an important quantity whose positivity is a necessary and sufficient condition for a general tensor to be a strictly semi-positive tensor. The monotonicity and boundedness of such a quantity are established too.     

The Monge-Ampère Equation for Strictly $(n−1)$-Convex Functions with Neumann Condition

A $C^2$ function on $\mathbb{R}^n$ is called strictly $(n-1)$-convex if the sum of any $n-1$ eigenvalues of its Hessian is positive. In this paper, we establish a global $C^2$ estimates to the Monge-Ampère equation for strictly $(n-1)$-convex functions with Neumann condition. By the method of continuity, we prove an existence theorem for strictly $(n-1)$-convex solutions of the Neumann problems.     

The correlation dimension of the Sierpinski carpet

We compute the correlation dimension of a measure defined on a general Sierpinski carpet. We relate this function to a free energy function associated to a partition composed of ‘nearly squares’ and well fitted to the planar Cantor set. Actually, we prove that these functions are real analytic on , are strictly increasing and are strictly concave (respectively linear in the degenerate case). This is an example of a two-dimensional dynamical system contracting in the two directions with different ratios. We first study measures of Gibbsian type before generalizing to Markovian measures.     

On the strict contractibility of polyhedra

In this paper we study conditions under which a compact contractible polyhedron is strictly contractible to a point.