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1.
集值映射空间的收敛与邻近结构   总被引:4,自引:0,他引:4  
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。  相似文献   

2.
We prove that, in the case of double series, perfect and unconditional convergences coincide, while absolute and perfect convergences do not coincide even for numerical series.  相似文献   

3.
Omid Zabeti 《Positivity》2018,22(2):501-505
Several recent papers investigated unbounded versions of order and norm convergences in Banach lattices. In this paper, we study the unbounded variant of weak convergence and its relationship with other convergences. In particular, we characterize order continuous Banach lattices and reflexive Banach lattices in terms of this convergence.  相似文献   

4.
We study some basic properties of the so-called bornological convergences in the realm of quasi-uniform spaces. In particular, we revisit the results about when these convergences are topological by means of the use of pretopologies. This yields a presentation of the bornological convergences as a certain kind of hit-and-miss pretopologies. Furthermore, we characterize the precompactness and total boundedness of the natural quasi-uniformities associated to these convergences. We also obtain an extension of the classical result of Künzi and Ryser about the compactness of the topology generated by the Hausdorff quasi-uniformity to this framework.  相似文献   

5.
We study the complete lattice of convergences, that is, of relations between a set and the set of its filters. Various properties of convergences (like isotonicity, antitonicity, being a pseudotopology, a pretopology, an adherence) determine subsets of the lattice of convergences which possess certain particular features called “cyrtological”. The morphisms associated to these sets, said “cyrtomorphisms”, are basic in the study of convergences. A method of generation of GALOIS connections relative to cyrtomorphisms is proposed. Semigroups generated by some cyrtomorphisms are analyzed.  相似文献   

6.
模糊拓扑空间的m—收敛理论   总被引:3,自引:0,他引:3  
本文在模糊拓扑空间中引进了模糊网和模糊滤子的m-收敛概念,探讨了模糊网的m-收敛与模糊滤子的m-收敛之间的关系,得到了Hausdorff拓扑与模糊网的m-收敛和模糊滤子的m-收敛之间的关系以及刻画Hausdorff拓扑几何特征的定理。  相似文献   

7.
最优化方法中的直接法是仅仅利用目标函数值(或者通过试验结果)的信息,试图去寻求最优解.直接法迭代步骤简单,特别当目标函数的解析表达式十分复杂,甚至写不出来时,那些要求计算目标函数的偏导数的方法(称为解析方法)就无能为力了.然而,多因  相似文献   

8.
The purpose of this paper is to compare several kinds of convergences on the space C(X) of nonempty closed convex subsets of a locally convex space X. First we verify that the AW-convergence on C(X) is weaker than the metric Attouch-Wets convergence on C(X) of a metrizable locally convex space X. Moreover, we show that X is normable if and only if the two convergences on C(X × R) are equivalent. Secondly we define two convergences on C(X) analogous to the corresponding ones in a normed linear space, and investigate some basic properties of these convergences and compare them.  相似文献   

9.
充分条件1和2,对于SOR迭代(0<ω≤1)和AOR迭代(0≤r≤1,0<ω≤1)也是适用的。那么,充分条件3对于SOR迭代和AOR迭代是否适用呢?迄今为止尚没有讨论过。这里我们给予肯定的回答。我们的结论基于如下两个引理。 引理1 如果A的主对角元全不为零,且满足条件(4),则detA≠0。 引理2 对线性方程组(1)的迭代法  相似文献   

10.
经典测度的弱收敛和淡收敛在经典概率论等随机数学理论中有着很重要的作用。在局部紧Hausdorff空间中首次引入了一类紧Fuzzy 测度序列的淡收敛的概念,得到了它的等价形式及一些性质,推广了相应的经典结果。  相似文献   

11.
Some abstract results about convergences for a sequence of parameterized nonempty closed convex sets, in the Mosco sense as well as in the sense of the local gap have been proved. By using these results, the convergences of some sequences of closed convex sets by certain general concrete structures arc discussed.  相似文献   

12.
Bornological convergence is a generalization of the well known Attouch–Wets convergence. Our aim is to compare lower, upper and “two-sided” convergences generated by two compatible uniformities and two arbitrary bornologies. Moreover, the comparison of convergences induced by bounded-proximal topologies is characterized.  相似文献   

13.
We study sequential convergences defined on a Boolean algebra by systems of maximal filters. We describe the order properties of the system of all such convergences. We introduce the category of 2-generated convergence Boolean algebras and generalize the construction of Novak sequential envelope to such algebras.  相似文献   

14.
许福 《应用数学》1993,6(4):387-391
本文给出了Ritz-Galerkin解法的收敛性,并对模型问题的块Jacobi和平行弦方法进行了收敛性分析。Bers在1964年给出模型问题差分方法收敛性的证明,这里得到了块Jacobi块SOR、块Newton-Jacobi和块Newton-Sor四种算法的收敛性结果。以上这些Jacobi算法都适合于并行计算,最后给出两个具体数值例子。  相似文献   

15.
We present, in a bounded domain, a model of an l -periodic structure composed of two phases, both being connected but only one reaching the boundary of the domain, avoiding in this way the local type convergences of the homogenization process. In this framework we revise some basic tools of the homogenization theory in porous media: the extension and the restriction operators, the Ne ) as inequality. Moreover, we obtain some compacity properties which reduce the proof of the pressure type convergences from the homogenization of fluid flows through porous media to the expected procedure of a priori estimations and two-scale convergences. As all the properties can be proved without much technical difficulties, avoiding annoying hypotheses and the use of Kolmogorov's criterion of compacity, the present structure seems one of the most convenient realistic models of porous media that can be studied with the methods of homogenization.  相似文献   

16.
We investigate partially ordered normed vector spaces in which the norm convergence coincides with the order convergence. We consider spaces where the convergences coincide for arbitrary nets and spaces where the convergences coincide only for sequences. We give conditions which characterize such spaces and investigate their properties. In particular, we study the problem of their Dedekind completeness and -completeness.Translated from Matematicheskie Zametki, Vol. 13, No. 2, pp. 259–268, February, 1973.  相似文献   

17.
Wang  Zhangjun  Chen  Zili  Chen  Jinxi 《Archiv der Mathematik》2021,117(3):305-313
Archiv der Mathematik - Recently, the different types of unbounded convergences $$(uo, un, uaw, ua w^*)$$ in Banach lattices were studied. In this paper, we study the continuous functionals with...  相似文献   

18.
We generalize the notion of a coarse sequential convergence compatible with an algebraic structure to a coarse one in a given class of convergences. In particular, we investigate coarseness in the class of all compatible convergences (with unique limits) the restriction of which to a given subset is fixed. We characterize such convergences and study relative coarseness in connection with extensions and completions of groups and rings. E.g., we show that: (i) each relatively coarse dense group precompletion of the group of rational numbers (equipped with the usual metric convergence) is complete; (ii) there are exactly exp exp such completions; (iii) the real line is the only one of them the convergence of which is Fréchet. Analogous results hold for the relatively coarse dense field precompletions of the subfield of all complex numbers both coordinates of which are rational numbers.  相似文献   

19.
This paper aims to study the asymptotic behavior of a fast-slow stochastic dynamical system with singular coefficients, where the fast motion is given by a continuous diffusion process while the slow component is driven by an α-stable noise with α ∈ [1, 2). Using Zvonkin’s transformation and the technique of the Poisson equation, we have that both the strong and weak convergences in the averaging principle are established, which can be viewed as a functional law of large numbers. Then we study t...  相似文献   

20.
Topological sequential spaces are the fixed points of a Galois correspondence between collections of open sets and sequential convergence structures. The same procedure can be followed replacing open sets by other topological concepts, such as closure operators or (ultra)filter convergences. The fixed points of these other Galois correspondences are not topological spaces in general, but they can be embedded into the larger topological classes of pretopological, pseudotopological and convergence spaces. In this paper, we characterize the sequential convergences which are fixed points of these correspondences as well as their restrictions to topological spaces.  相似文献   

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