模糊拓扑空间中Moore-Smith收敛性的非标准刻画

应用了公理化非标准分析理论,将经典集合X上的模糊集扩张成*X上的模糊集.在非标准扩大模型中,定义了模糊邻近结构的单子,并讨论了这些单子的性质及其之间的关系.利用这些单子,刻画了模糊拓扑空间中模糊网的收敛性,进而得到了模糊拓扑空间中Moore-Smith收敛理论的非标准刻画.     

单子理论对拓扑等度连续与均匀连续的刻画及其应用

在扩大模型下,应用单子理论给出了拓扑等度连续和均匀连续的非标准刻画,并应用均匀连续的非标准特征证明了网收敛与均匀连续之间的关系,最后应用拓扑等度连续和均匀连续的非标准特征证明了拓扑等度连续和均匀连续之间的关系.     

L-fuzzy拓扑空间上的Dα-收敛性

在L-fuzzy拓扑空间中,利用Dα-闭集定义了分子网的Dα-附着点、Dα-极限点、Dα-聚点等概念 . 系统讨论了这些概念的基本性质.     

LF拓扑空间中的θ—收敛性（Ⅱ）

本文在LF拓扑空间中引进理想的θ-极限点和θ-聚点等概念,系统地研究理想的θ-收敛性的特征以及理想的θ-收敛性与分子网的θ-收敛性之间的关系。最后,利用理想的θ-收敛性刻画弱连续序同态、几乎连续序同态以及几乎F紧性。     

万有网的非标准特征及其应用

通过利用非标准分析中的扩大模型,对拓扑空间中的万有网进行了讨论,从而获得了万有网的非标准特征,并进一步利用这一性质对万有网及其相关的性质、定理做了证明.     

Lω-空间中的ω-Urysohn分离性

在Lω-空间中引入分子网和理想的ωθ*-极限点、ωθ*-聚点等概念,证明ω-Urysohn空间中分子网和理想的ωθ*-极限点均唯一等特征性质,并证明ω-Urysohn分离性是可ω-遗传的,在(ω1,ω2)-同胚和(ω1,ω2)θ-同胚映射下是拓扑不变的,在满层条件下是任意可乘的,而且是R.Lowen意义下好的推广等性质。     

点星网与度量空间的映像

拓扑空间X的覆盖列{P_i}_(i∈N)被称为空间X的点星网,若x∈X,则{st(x,P_i)}_(i∈N)是x在X中的网.本文刻画具有cs有限cs覆盖列的点星网的空间,并将其表示为度量空间在确定映射下的像.在假设集族性质β满足适当的条件下,证明对拓扑空间X下述条件相互等价:(1) X具有β且cs覆盖列的点星网.(2)X具有β且sn覆盖列的点星网.(3)X是Cauchy sn对称空间且具有σ-β的cs网.(4) X是Cauchy sn对称空间且具有σ-β的sn网.(5) X是度量空间的序列覆盖、π且σ-β映像.(6) X是度量空间的1序列覆盖、紧且σ-β映像.这些工作以局部有限集族与点有限集族为特例,拓展了从基到cs网的研究,丰富了映射与空间的相互分类思想.     

连续树映射的ω极限集与非游荡集

本文研究树上连续自映射f的ω极限集∧,非游荡集Ω的若干拓扑结构,主要证明了不在周期点集闭包中的ω极限点都有无限轨迹;Ω-     

无穷小延伸定理的推广及其应用

本文在饱和的非标准模型中把无穷小延伸定理推广到网的情形,做为应用,利用推广了的无穷小延伸定理给出拓扑空间中连续泛函的一个重要性质的离散化证明.     

L-预拓扑空间中模糊网的O-收敛及其应用

利用L-点的邻域研究了L-预拓扑空间中模糊网的O-收敛性,在此基础上刻画了L-预拓扑空间中的闭集、开集以及模糊紧集,并给出T2L-预拓扑空间的两个判据。     

Set-valued dynamic systems and random iterations of set-valued weaker contractions in uniform spaces

Set-valued weaker contractions in uniform, locally convex and metric spaces are defined and dynamic systems of such weaker contractions are studied. Conditions guaranteeing the convergence of generalized sequences of random iterations and iterations and the existence and uniqueness of endpoints of set-valued weaker contractions are established. Our definitions and results are new for set-valued maps in uniform, locally convex and metric spaces and even for single-valued maps.     

Radon-Nikodym theorems for set-valued measures

Set-valued measures whose values are subsets of a Banach space are studied. Some basic properties of these set-valued measures are given. Radon-Nikodym theorems for set-valued measures are established, which assert that under suitable assumptions a set-valued measure is equal (in closures) to the indefinite integral of a set-valued function with respect to a positive measure. Set-valued measures with compact convex values are particularly considered.     

非标准分析的产生与早期发展

非标准分析是微积分在20世纪的新发展,并且对现代数学的多个分支及层面产生了深刻的影响.通过考察相关资料,研究了非标准分析的产生、非标准分析的早期发展,进而使人们对非标准分析这一工具有所了解.     

Selections and selectors

The aim of the paper is to outline the known results and the main technics they are obtained with as well as the open questions about selections of set-valued mappings. More precisely the following topics will be touched: Set-valued selections of set-valued mappings, factorizations of set-valued mappings, inverse selection theorems, selections via extension of the set-valued mapping.     

Set-Valued Functions of Bounded Generalized Variation and Set-Valued Young Integrals

Journal of Theoretical Probability - The paper deals with some properties of set-valued functions having bounded Riesz p-variation. Set-valued integrals of Young type for such multifunctions are...     

Set-Valued Means

Set-Valued and Variational Analysis - The notion of set-valued means is introduced. Set-valued counterparts of the arithmetic, quasi-arithmetic and Lagrangian means are investigated and various...     

Characterizations of strictly convex sets by the uniqueness of support points

Abstract

This short paper characterizes strictly convex sets by the uniqueness of support points (such points are called unique support points or exposed points) under appropriate assumptions. A class of so-called regular sets, for which every extreme point is a unique support point, is introduced. Closed strictly convex sets and their intersections with some other sets are shown to belong to this class. The obtained characterizations are then applied to set-valued maps and to the separation of a convex set and a strictly convex set. Under suitable assumptions, so-called set-valued maps with path property are characterized by strictly convex images of the considered set-valued map.     

关于Robinson序列引理的注记

The Infintesimal Prolongation Theorem is extended from sequences to nets in k-saturated nonstandard model. As its application, a main property about the topology of uniform convergence is proved. The proof is much simpler than it was; meanwhile, the nonstandard characteristics of convergence with respect to u.c. topology are given.     

拓扑空间到拓扑空间的集值映射的若干定理和等价命题

集值映射已成为数理经济学的一个基本工具,集值映射在经济理论分析中的应用也推动了集值影射本身在数学上的发展.有关集值映射的特性主要建立在欧试空间或度量空间中,这些性质也可以推广到拓扑空间中,但相应的假设较强,其实际应用范围不太理想.本文在主要条件有所减弱的情况下,在拓扑空间中建立集值映射的有关概念和性质,对给出的一些定理进行证明,且得出其他一些结果,如给出极大定理的另一表述和证明.