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1.
For a Tychonoff space X,we use ↓USC F(X) and ↓C F(X) to denote the families of the hypographs of all semi-continuous maps and of all continuous maps from X to I = [0,1] with the subspace topologies of the hyperspace Cld F(X × I) consisting of all non-empty closed sets in X × I endowed with the Fell topology.In this paper,we shall show that there exists a homeomorphism h:↓USC F(X) → Q = [1,1] ω such that h(↓CF(X))=c0 = {(xn)∈Q| lim n→∞ x n = 0} if and only if X is a locally compact separable metrizable space and the set of isolated points is not dense in X.  相似文献   

2.
Let (X, ρ) be a metric space and ↓USCC(X) and ↓CC(X) be the families of the regions below all upper semi-continuous compact-supported maps and below all continuous compact-supported maps from X to I = [0, 1], respectively. With the Hausdorff-metric, they are topological spaces. In this paper, we prove that, if X is an infinite compact metric space with a dense set of isolated points, then (↓USCC(X), ↓CC(X)) ≈ (Q, c0 ∪ (Q \ Σ)), i.e., there is a homeomorphism h :↓USCC(X) → Q such that h(↓CC(X)) = c0 ∪ (Q \ Σ...  相似文献   

3.
Let L be a continuous semilattice. We use USC(X, L) to denote the family of all lower closed sets including X × {0} in the product space X × AL and ↓1 C(X,L) the one of the regions below of all continuous maps from X to AL. USC(X, L) with the Vietoris topology is a topological space and ↓C(X, L) is its subspace. It will be proved that, if X is an infinite locally connected compactum and AL is an AR, then USC(X, L) is homeomorphic to [-1,1]ω. Furthermore, if L is the product of countably many intervals, then ↓ C(X, L) is homotopy dense in USC(X,L), that is, there exists a homotopy h : USC(X,L) × [0,1] →USC(X,L) such that h0 = idUSC(X,L) and ht(USC(X,L)) C↓C(X,L) for any t > 0. But ↓C(X, L) is not completely metrizable.  相似文献   

4.
Under the framework of uniformly smooth Banach spaces, Chang proved in 2006 that the sequence {xn} generated by the iteration xn+1 =αn+1f(xn) + (1 - αn+1)Tn+1xn converges strongly to a common fixed point of a finite family of nonexpansive maps {Tn}, where f : C → C is a contraction. However, in this paper, the author considers the iteration in more general case that {Tn} is an infinite family of nonexpansive maps, and proves that Chang's result holds still in the setting of reflexive Banach spaces with the weakly sequentially continuous duality mapping.  相似文献   

5.
张丽丽  杨忠强 《数学进展》2007,36(3):349-353
令(X,d)是紧的度量空间,用↓USC(X)和↓LIP(X)分别表示从X到I所有的上半连续映射和所有Lipschitz映射的下方图形的全体.本文证明如果X是一个无限的紧的度量空间,则(↓USC(X),↓LIP(X))≈(Q,B(Q)),其中B(Q)=Q\(-1,1)~ω是Hilbert立方体Q=[-1,1]~ω的伪边界.  相似文献   

6.
Let T = (T(t))t≥0 be a bounded C-regularized semigroup generated by A on a Banach space X and R(C) be dense in X. We show that if there is a dense subspace Y of X such that for every x ∈ Y, σu(A, Cx), the set of all points λ ∈ iR to which (λ - A)^-1 Cx can not be extended holomorphically, is at most countable and σr(A) N iR = Ф, then T is stable. A stability result for the case of R(C) being non-dense is also given. Our results generalize the work on the stability of strongly continuous senfigroups.  相似文献   

7.
ZhongHuaijie 《数学研究》1994,27(1):204-208
We generalize Kadec‘s and Yan Zikun‘s resuhs in [1],[2] to prove; in every infinite dimensional real Banach space Y there exist an infinite dimensional subspace X and a series ∑xn such that ∑xn has property(N) in X. but(the domain of sums of this series) S(∑xn) is not a convex set.  相似文献   

8.
9.
《数学季刊》2016,(4):430-434
It is proved in this paper that (1) the topological sum of a family of supercomplete spaces is supercomplete; (2) if X is a metacompact and almost locally compact space then X is supercomplete. Moreover, some questions on supercomplete spaces are posed in the paper.  相似文献   

10.
Let X be a compact metric space and T:X-→X be continuous.Let h*(T)be the supremum of topological sequence entropies of T over all the subsequences of Z+and S(X)be the set of the values h*(T)for all the continuous maps T on X.It is known that{0}■S(X)■{0,log 2,log 3,...}∪{∞}.Only three possibilities for S(X)have been observed so far,namely S(X)={0},S(X)={0,log 2,∞}and S(X)={0,log 2,log 3,...}∪{∞}.In this paper we completely solve the problem of finding all possibilities for S(X)by showing that in fact for every set{0}?A?{0,log 2,log 3,...}∪{∞}there exists a one-dimensional continuum XAwith S(XA)=A.In the construction of XAwe use Cook continua.This is apparently the first application of these very rigid continua in dynamics.We further show that the same result is true if one considers only homeomorphisms rather than continuous maps.The problem for group actions is also addressed.For some class of group actions(by homeomorphisms)we provide an analogous result,but in full generality this problem remains open.  相似文献   

11.
In this paper,we develop a correction operator for the canonical interpolation operator of the Adini element.We use this new correction operator to analyze the discrete eigenvalues of the Adini element method for the fourth order elliptic eigenvalue problem in the three dimensions.We prove that the discrete eigenvalues are smaller than the exact ones.  相似文献   

12.
针对2007年全国大学生数学建模竞赛B题——"乘公交,看奥运"中的关于公交线路的选择问题,建立了最短时间的数学模型,并给出了该数学模型的精确求解.  相似文献   

13.
针对保险索赔次数数据,本文基于混合Poisson分布研究了保险中集合保单不同质性的度量方法;给出不同质性系数的定义、估计方法及实例。  相似文献   

14.
针对我国变电工程造价评价传统指标单位主变电容量(元/MVA),以60个500KV典型变电工程为样本,首先经过文献研究分析,筛选出变电总容量、无功补偿容量、高压侧出线回路数和高抗器容量等4个指标进行工程造价关键影响因素分析.其次利用多元线性回归分析(Multiple linear regression analysis)技术进行因素相关性检验与敏感性分析.再次根据生产要素理论将关键影响因素设计进新评价指标中,指出它们的应用范围,组建新评价指标体系.最后进行样本检验以确保结论的准确性.结果表明评价指标体系的建立,弥补了传统造价评价指标缺陷,同时能够显著提高变电工程造价管理水平.  相似文献   

15.
费威 《经济数学》2013,30(2):1-6
为提高我国食品质量安全水平,对小型、分散的单个供应商和一个制造商构成的食品供应链中,制造商对原材料和最终食品进行质量检测的情况,建立了以供应商和制造商各自的质量水平为决策变量的优化模型,分析了最优质量水平的影响因素和影响效应.并依据结论提出相应建议,如提高消费者对优劣食品的识别能力,发挥制造商在供应链中的监督检验作用等.  相似文献   

16.
图表示范畴的两个子范畴   总被引:1,自引:0,他引:1  
林卫强 《数学研究》2001,34(4):416-421
引进图表示范畴的两个子范畴,研究它们的同调性质。  相似文献   

17.
利用小波变换能够表征信号特征的特性 ,选取适当小波函数 ,对 Gauss函数作小波变换 ,根据小波变换零值点和极值点来判别 Gauss函数极值点和拐点 ,根据小波变换的变化情况来判别 Gauss函数的重叠情况 .结果表明是有效的 .  相似文献   

18.
更新换代产品创意的生成方法分析   总被引:3,自引:0,他引:3  
本文从方法论的角度 ,应用物元理论分析更新换代产品创意的生成方法和过程 ,探索其内在规律性 .  相似文献   

19.
在把房地产投资开发项目看作为一种具有弱再生性经济资源的基点上,对房地产投资开发活动进行了均衡分析,讨论了房地产开发活动中的最优平衡解及其相互之间的制约关系,分析了税收和配额价格等经济参数对最优平衡解的影响,给出了抑制房地产过度投资开发行为的控制模型与方法,并得出了相应的政策启示.这些研究结果,可以推广应用于其他各种可再生资源的投资开发与管理当中去,有着广泛的应用前景.  相似文献   

20.
需求区间型运输问题的求解算法   总被引:4,自引:1,他引:3  
为了便于建立与需求区间型运输问题有关的决策支持系统,本给出了一个求解需求区间型运输问题的数值算法,证明了算法的理论依据,并举例说明算法的应用,该算法能求得问题的最优解,并具有易于编程实现、收敛性好等优点,大量数值实验表明该算法有较高的计算效率。  相似文献   

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