集值映射空间的收敛与邻近结构

S.Lubkin[1]对一个集合X定义邻近结构u,并把(X,u)称为空间。邻近结构是介于拓扑结构和一致结构之间的一种结构。本文将以作者在[6]中使用的集合间包含运算为工具,研究集值映射空间的邻近结构,以及刻划集值映射网的各种收敛的各种邻近结构。     

模糊化的Egoroff定理

在一般模糊测度空间上,针对可测模糊值函数序列给出了几乎处处收敛,几乎一致收敛和伪几乎一致收敛的概念,并在此基础上,进一步研究了这几种收敛的蕴涵关系,从而获得了模糊化的Egoroff定理,使模糊值函数序列的理论得到进一步丰富.     

关于函数空间上三个特殊拓扑满足第一可数公理的条件

本文给出了函数空间上的一致收敛拓扑、紧收敛拓扑及 Cauchy收敛拓扑满足第一可数公理的条件 .     

实Clifford分析中超正则函数列和函数空间的性质

定义了实Clifford分析中超正则函数列的一致有界、内闭一致有界及内闭一致收敛等概念,并讨论了超正则函数列及超正则函数空间的几条性质.     

广义函数Denjoy积分的收敛性问题

本文讨论广义函数De njoy积分的收敛性问题.首先给出了广义Denjoy可积函数空间中强收敛、弱收敛、弱~*收敛和广义函数Denjoy积分收敛的关系;证明拟一致收敛是广义函数Denjoy积分收敛的一个充分必要条件;最后指出了Denjoy可积广义函数列弱~*收敛与强收敛等价当且仅当原函数等度连续.     

Fuzzy拓扑共生预序空间

文[1]给出了研究拓扑空间,邻近空间,一致空间的统一化理论的方法,提出了拓扑共生结构的概念。文[3,4]引入了Fuzzy拓扑共生结构,初步研究了Fuzzy拓扑,Fuzzy邻近结构,Fuzzy一致结构的统一化问题,文[5]讨论了Fuzzy拓扑共生结构生成     

关于函数空间Y~X上三个特殊拓扑间关系的讨论

本文对函数空间上的一致收敛拓扑、紧收敛拓扑及 Cauchy收敛拓扑之间的关系进行了讨论 ,给出了这三个拓扑间两两等价的充要条件     

模糊拟邻近结构与模糊双拓扑

本文给出了模糊拟邻近结构的概念，并着重讨论了模糊拟邻近结构与模糊双拓扑，模糊拟邻近结构与模糊拟一致空间之间的相互联系。     

Fuzzy值函数项级数的一致收敛性

本文是引文[1,2]的继续。本文引入了Fuzzy值函数项级数的收敛和一致收敛的概念;给出了Fuzzy值函数项级数的一致收敛的判别法;研究了Fuzzy值函数项级数的和函数的连续性与Fuzzy值函数项级数的逐项求导和逐项积分问题。     

函数列的黎曼积分极限定理的应用

利用函数列的极限理论方法,研究函数列积分极限中积分和极限可交换次序的问题.对一致收敛的可积函数列给出积分的极限定理,对一致有界局部一致收敛函数列给出积分控制收敛定理,通过大量实例表明该理论的意义所在.     

Convergence of Polynomial Level Sets

In this paper we give a characterization of pointwise and uniform convergence of sequences of homogeneous polynomials on a Banach space by means of the convergence of their level sets. Results are obtained both in the real and the complex cases, as well as some generalizations to the nonhomogeneous case and to holomorphic functions in the complex case. Kuratowski convergence of closed sets is used in order to characterize pointwise convergence. We require uniform convergence of the distance function to get uniform convergence of the sequence of polynomials.

     

Approximation of lipschitz functions by Δ-convex functions in banach spaces

In this paper we give some result about the approximation of a Lipschitz function on a Banach space by means of Δ-convex functions. In particular, we prove that the density of Δ-convex functions in the set of Lipschitz functions for the topology of uniform convergence on bounded sets characterizes the superreflexivity of the Banach space. We also show that Lipschitz functions on superreflexive Banach spaces are uniform limits on the whole space of Δ-convex functions.     

The quasi-metric of complexity convergence

For any weightable quasi-metric space (X, d) having a maximum with respect to the associated order ≤ _d , the notion of the quasi-metric of complexity convergence on the the function space (equivalently, the space of sequences) X^ω , is introduced and studied. We observe that its induced quasi-uniformity is finer than the quasi-uniformity of pointwise convergence and weaker than the quasi-uniformity of uniform convergence. We show that it coincides with the quasi-uniformity of pointwise convergence if and only if the quasi-metric space (X, d) is bounded and it coincides with the quasi-uniformity of uniform convergence if and only if X is a singleton. We also investigate completeness of the quasi-metric of complexity convergence. Finally, we obtain versions of the celebrated Grothendieck theorem in this context.     

A higher order difference method for singularly perturbed parabolic partial differential equations

This paper studies a higher order numerical method for the singularly perturbed parabolic convection-diffusion problems where the diffusion term is multiplied by a small perturbation parameter. In general, the solutions of these type of problems have a boundary layer. Here, we generate a spatial adaptive mesh based on the equidistribution of a positive monitor function. Implicit Euler method is used to discretize the time variable and an upwind scheme is considered in space direction. A higher order convergent solution with respect to space and time is obtained using the postprocessing based extrapolation approach. It is observed that the convergence is independent of perturbation parameter. This technique enhances the order of accuracy from first order uniform convergence to second order uniform convergence in space as well as in time. Comparative study with the existed meshes show the highly effective behavior of the present method.     

关于概率赋范线性空间上的线性算子的一致收敛

本文引入了概率赋范线性空间上线性算子的一致收敛和可完全刻划这种收敛的算子间的概率距离概念,并利用这些概念获得了算子连续和算子列一致收敛的本质特征,及其连续性和全连续性对于一致收敛极限运算的封闭性.     

Best Proximity Points for Cyclic Mappings in Ordered Metric Spaces

In this paper we consider a cyclic mapping on a partially ordered complete metric space. We prove some fixed point theorems, as well as some theorems on the existence and convergence of best proximity points.     

Best Proximity Points for Cyclic Mappings in Ordered Metric Spaces

In this paper, we consider a cyclic mapping on a partially ordered complete metric space. We prove some fixed point theorems, as well as some theorems on the existence and convergence of best proximity points.     

Generalized Dini theorems for nets of functions on arbitrary sets

We characterize the uniform convergence of pointwise monotonic nets of bounded real functions defined on arbitrary sets, without any particular structure. The resulting condition trivially holds for the classical Dini theorem. Our vector-valued Dini-type theorem characterizes the uniform convergence of pointwise monotonic nets of functions with relatively compact range in Hausdorff topological ordered vector spaces. As a consequence, for such nets of continuous functions on a compact space, we get the equivalence between the pointwise and the uniform convergence. When the codomain is locally convex, we also get the equivalence between the uniform convergence and the weak-pointwise convergence; this also merges the Dini-Weston theorem on the convergence of monotonic nets from Hausdorff locally convex ordered spaces. Most of our results are free of any structural requirements on the common domain and put compactness in the right place: the range of the functions.