关于广义Muirhead平均的Schur幂凸性

对广义Muirhead平均的Schur-幂凸性进行了讨论,给出了判定Muirhead平均的Schur-幂凸性的充要条件.结果改进了Chu和Xia在相关文献中的主要结果,Chu和Xia的结果是结果的特例.     

两个反三角平均的Schur凸性及不等式链

关于张帆,钱伟茂所定义的四个反三角函数平均,利用Hermite-Hadamard不等式证得其中两个反三角平均:Marcsin(a,b)分别是Schur-凸,Schur-几何凸,Schur-调和凸;Marctan(a,b)分别是Schur-凹,Schur-几何凸,Schur-调和凸,并结合凸函数理论得出若干不等式链.     

二元copula Schur-凹的一个新特征

给出二元copula Schur-凹的一个新特征,利用此特征研究若干copula的Schur-凹性,同时研究此特征与上迁移之间的联系.     

Lehme平均的Schur凸性和Schur几何凸性

讨论了二元Lehme平均Lp(a,b)关于变量(a,b)在R+2+上的Schur凸性和Schur几何凸性,并建立了相应的不等式.     

完全对称函数的Schur凸性

定义了一完全对称函数并研究该称函数的Schur凸性,Schur乘性凸性及Schur调和凸性,作为应用探讨了与其相关的一些不等式.     

集合的$\varOmega$-凸性及其基础性质[英文]

作为集合凸性概念的一种推广以及统一凸性与近似（nearly）凸性等概念的一种尝试, 本文引入集合$\varOmega$-凸性的概念, 并对$\varOmega$-凸集合的性质进行初步的研究. 另外, 本文还研究了一些常见变换与集合运算的保$\varOmega$-凸性质.     

关于P-凸性与F-凸性的一些注记（英文）

本文得到在赋Orlicz范数(或Luxemburg范数)下Orlicz-Bochner序列空间l_M(X_s)为P-凸的当且仅当l_M是P-凸的,且{X_s}为等度P-凸的.据此可得l_M(X_s)为F-凸的当且仅当l_M是F-凸的,且{X_s}为等度F-凸的.本文也讨论了Orlicz-Bochner函数空间L_M(μ,X)中的F-凸性.     

关于一类对称函数的Schur凸性

利用Schur凸函数、Schur几何凸函数和Schur调和凸函数的有关性质简化证明了一类与对数凸函数有关的对称函数的Schur凸性、Schur几何凸性和Schur调和凸性.     

关于随机一致凸性

致力于随机一致凸性概念的进一步探讨．首先,通过一个特殊的层次剖分指出对任意的随机赋范模而言随机凸性模都有良好定义,从而改进了近期的文献中许多已知的结果．然后,提出并研究了一种与随机一致凸性密切相关的新性质,从一个新的角度阐述了随机一致凸性的复杂性．     

凸对策核仁的非空性及合成凸对策核仁的单调性

本文给出了核仁与核及最小核心之间的关系 ,且证明了凸对策核仁的存在性和唯一性 ,证明了凸对策的合成对策仍是凸对策 .最后 ,我们讨论了合成凸对策的核仁不满足单调性 .     

二元凸函数的判别条件

给出了二元凸函数的定义,导出了二元凸函数的判别条件,该判别条件由二元函数的二阶导数给出.用二元凸函数的判别条件和半正定的(半负定)矩阵的性质,得到了二元二次多项式凸性的简单判别形式.     

Convexity in Scheduling Problems

凸性在连续性最优化理论中起着重要的作用．它在离散性最优化中的相应概念尚待研究．本文运用差分和次梯度的概念给出排序问题中离散凸性的描述，并指出凸性在构造最优排序中的重要性．     

Strong Restricted-Orientation Convexity

Strong restricted-orientation convexity is a generalization of standard convexity. We explore the properties of strongly convex sets in multidimensional Euclidean space and identify major properties of standard convex sets that also hold for strong convexity. We characterize strongly convex flats and halfspaces, and establish the strong convexity of the affine hull of a strongly convex set. We then show that, for every point in the boundary of a strongly convex set, there is a supporting strongly convex hyperplane through it. Finally, we show that a closed set with nonempty interior is strongly convex if and only if it is the intersection of strongly convex halfspaces; we state a condition under which this result extends to sets with empty interior.     

Convexity of Domains of Riemannian Manifolds

In this paper the problem of the geodesic connectedness and convexity ofincomplete Riemannian manifolds is analyzed. To this aim, a detailedstudy of the notion of convexity for the associated Cauchy boundary iscarried out. In particular, under widely discussed hypotheses,we prove the convexity of open domains (whose boundaries may benondifferentiable) of a complete Riemannian manifold. Variationalmethods are mainly used. Examples and applications are provided,including a result for dynamical systems on the existence oftrajectories with fixed energy.     

Convexity and marginal vectors

In this paper we construct sets of marginal vectors of a TU game with the property that if the marginal vectors from these sets are core elements, then the game is convex. This approach leads to new upperbounds on the number of marginal vectors needed to characterize convexity. Another result is that the relative number of marginals needed to characterize convexity converges to zero. Received: May 2002     

The Forcing Convexity Number of a Graph

For two vertices u and v of a connected graph G, the set I(u,v) consists of all those vertices lying on a u-v geodesic in G. For a set S of vertices of G, the union of all sets I(u,v) for u, v S is denoted by I(S). A set S is a convex set if I(S) = S. The convexity number con(G) of G is the maximum cardinality of a proper convex set of G. A convex set S in G with |S| = con(G) is called a maximum convex set. A subset T of a maximum convex set S of a connected graph G is called a forcing subset for S if S is the unique maximum convex set containing T. The forcing convexity number f(S, con) of S is the minimum cardinality among the forcing subsets for S, and the forcing convexity number f(G, con) of G is the minimum forcing convexity number among all maximum convex sets of G. The forcing convexity numbers of several classes of graphs are presented, including complete bipartite graphs, trees, and cycles. For every graph G, f(G, con) con(G). It is shown that every pair a, b of integers with 0 a b and b is realizable as the forcing convexity number and convexity number, respectively, of some connected graph. The forcing convexity number of the Cartesian product of H × K ₂ for a nontrivial connected graph H is studied.     

一个模糊凸性的新的证明

用一种新的更传统的方法证明了在下半连续的条件下模糊凸性的两个充分条件.证明充分利用了下半连续即有最小值这一引理,没有沿用讨论该类模糊凸性问题常用方法,将模糊凸性的研究与传统分析中的有关内容融合、统一起来,给该类模糊凸性的研究提供了一种新的思路.     

保凸C^1分段二次多项式插值方法

本导出了二次多项式保凸的充要条件,通过插值部分新节点,得到了一种新的保凸Ｃ＾１分段二镒多项式插值函数。