L-双拓扑空间中的配超紧性

借助相关远域族给出L-双拓扑空间中配超紧性的定义,研究它们的等价刻画和基本性质,证明配超紧性是弱拓扑不变性.     

L-fuzzy拓扑空间中的几乎可数仿紧性

以可数仿紧性为背景,介绍几乎可数仿紧性的定义,并刻画其基本特征.深入研究L-fuzzy几乎可数仿紧性的性质,并证明几乎可敷仿紧性是"L-好的推广".     

L-模糊SP-紧集

本文在L-模糊拓扑空间引入了一种新的紧性—SP-紧性，给出了SP-紧性的α-网，α-滤子，r-SP-覆盖，r^ -有限交性质等多种刻画．这种紧性是针对任意L-模糊子集来定义的，且保持了一般拓扑空间中紧性的许多好的性质．     

弱STP-紧L-子集

在L-拓扑空间中引进了弱STP-紧性,它是一种介于良S-紧和弱PS-紧的紧性.文中给出弱STP-紧子集的定义,讨论了它的一些刻画,并的出一些好的性质.     

L-拓扑空间的相对α-紧性

研究了L-拓扑空间的相对α-紧集.基于α-紧性,在L-拓扑空间中引入相对α-紧性的概念,得到了它的一些性质,如它是L-好的推广,对α-闭子集遗传,被α-irresolute的广义Zadeh型函数所保持等.     

L-双拓扑空间的超Lindel(o)f性质

摘 要;借助α-相关远域族,在L-双拓扑空间中引入BPα-超Lindel(o)f空间和BP-超Lindel(o)f空间,研究了其等价刻画,证明了BP-超Lindel(o)f性质是弱同胚不变性和闭遗传性,是L-好的推广.     

LF-拓扑空间的良拟紧性

在LF-拓扑空间中证明了拟紧的推广良拟紧对于正则闭子集是可遗传的并且是L-好的推广.在LF-半正则空间中得到了良拟紧性等价于良紧性.     

L-fuzzy拓扑空间中的强Lindelf性质

本文在L-fuzzy拓扑空间中引进了强Lindelof性质以及与之有关的一些概念,给出了强Lindelof空间的等价刻划,证明了强Lindelof性质对闭子集遗传,是弱拓扑不变性质;当(L~x,ωL(?))具有强远域族性质时,(L~x,ωL(?))是强Lindelof空间当且仅当(X,(?))是Lindelof空间。此外,讨论了强Lindelof性质与良紧性、仿紧性之间的关系。     

L-fuzzy拓扑空间中的近似超紧性

利用相关远域族的概念介绍一种近似超紧性、讨论它与超紧性以及近似良紧性之间的关系,证明它具有正则闭遗传、有限可和、弱拓扑不变和乘积性等性质,并对它进行网式和滤子式刻画。     

L-拓扑空间中的W-仿紧性

利用α-局部有限族在L-拓扑空间中定义了一种新型强F仿紧性--W-仿紧性,证明了这种仿紧性具有一些好的性质,比如L-good extension,闭遗传,弱同胚不变性,强F紧集与W-仿紧集的乘积是W-仿紧集.并同时证明了W-仿紧性可以增强分离性,最后讨论了W-仿紧性与其他仿紧性之间的关系.     

L-拓扑空间中的相对强F紧性与相对超F紧性

In this paper,two concepts of relative compactness-the relative strong fuzzy compactness and the relative ultra-fuzzy compactness are defined in L-topological spaces for an arbitrary L-set.Properties of relative strong fuzzy sets and relative ultra-fuzzy compact sets are studied in detail and some characteristic theorems are given.Some examples are illustrated.     

Compact Operators on Homogeneous Banach Spaces of Distributions on Locally Compact Abelian Groups

In this paper, two theorems about the compactness of almost invariant operators on homogeneous Banach spaces of distributions (in the sense of Feichtinger [11]) defined on a locally compact abelian group are proved. Our theorems generalize the corresponding results of K. de Leeuw [3] and Tewari and Madan [18] for operators on homogeneous Banach spaces on the circle group and Segal algebras on a compact abelian groups, respectively.AMS Subject Classification 2000: 43A85, 47B07.     

Almost compactness in fuzzy topological spaces

We introduce and study almost compactness for fuzzy topological spaces. We show that the almost continuous image of an almost compact fuzzy topological space is almost compact. Moreover, we show that generally almost compactness for fuzzy topological spaces is not product-invariant, but if X and Y are almost fuzzy topological spaces and X is product related to Y, then their fuzzy topological product is almost compact.     

不分明化拓扑中近似紧性和几乎紧性

在不分明化拓扑空间中,从正则开集出发引入了近似紧性和几乎紧性的概念,并且给出了它们的一些性质.这些概念的结合有助于我们对不分明化拓扑的研究。     

PAIRWISE ALMOST COMPACT SPACES

ABSTRACT

The purpose of this paper is to investigate pairwise almost compact bitopological spaces. These spaces satisfy a bitopological compactness criterion which is strictly weaker than pairwise C-compactness and is independent of other well-known bitopological compactness notions. Pairwise continuous maps from such spaces to pairwise Hausdorff spaces are pairwise almost closed, the property is invariant under suitably continuous maps, is inherited by regularly closed subspaces and may be characterized in terms of certain covers as well as the adherent convergence of certain open filter bases. Some new natural bitopological separation axioms are introduced and in conjunction with pairwise almost compactness yield interesting results, including a sufficient condition for the bitopological complete separation of disjoint regularly closed sets by semi-continuous functions.     

几乎良紧集

在Ｌ－ｆｕｚｚｙ拓扑空间中提出了几乎良紧集的概念，研究了它的基本特征，讨论了它的性质，通过若干例揭示了几乎良紧性与其它一些Ｆｕｚｚｙ几乎紧性之间的联系。     

Hodge–de Rham numbers of almost complex 4-manifolds

We introduce and study Hodge–de Rham numbers for compact almost complex 4-manifolds, generalizing the Hodge numbers of a complex surface. The main properties of these numbers in the case of complex surfaces are extended to this more general setting, and it is shown that all Hodge–de Rham numbers for compact almost complex 4-manifolds are determined by the topology, except for one (the irregularity). Finally, these numbers are shown to prohibit the existence of complex structures on certain manifolds, without reference to the classification of surfaces.     

An Extension of the Contraction Principle

The concept of quasi-continuity and the new concept of almost compactness for a function are the basis for the extension of the contraction principle in large deviations presented here. Important equivalences for quasi-continuity are proved in the case of metric spaces. The relation between the exponential tightness of a sequence of stochastic processes and the exponential tightness of its transform (via an almost compact function) is studied here in metric spaces. Counterexamples are given to the nonmetric case. Relations between almost compactness of a function and the goodness of a rate function are studied. Applications of the main theorem are given, including to an approximation of the stochastic integral.