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1.
本文借助Burke-Michael条件引入两种集族性质,分析了它们与cs*网和ωes*网的关系,肯定地回答了1996年刘川和Y.Tanaka在Toplogy Proceedings上提出的下述问题:若具有σ点有限K网的k空间X不含有闭子空间同胚于Sω,那么X是否是gf可数空间?  相似文献   

2.
度量空间的紧覆盖s-像   总被引:13,自引:3,他引:13  
刘川  戴牧民 《数学学报》1996,39(1):41-44
本文了给出了度量空间和局部可分度量空间紧覆盖s-像的刻画,部分地回答了Michael-Nagami问题.  相似文献   

3.
无穷级数是数学分析、微积分、高等数学等课程的重要组成部分 ,它在组合数学、近似计算、敛散性判断等领域中起着不可估量的作用 .本文按照初等数学与高等数学相结合的原则 ,收集整理了无穷级数∑∞n =11n2 =π26 的二种证明方法 ,为同学们学习提供一些参考 .证法一 棣莫佛公式法 (DeMoiver)将DeMoiver公式 (cosα+isinα) k =coskα+isinkα按二项式定理展开为c0kcoskα +c1 kcosk- 1 α·isinα -c2 kcosk- 2 α·sin2 α +… +ckk(isinα) k =coskα+isin…  相似文献   

4.
{X,Xi,i≥1}是i.i.d.r.v′.s.在矩母函数存在的条件下,由古典的Erdos-Rényi大数律有limn→∞max0≤k≤n∑k+[clogn]i=k+1Xi[clogn]=α(c),α(c)为某常数.自正则下MiklósCsorgo&ShaoQiman(1994)在仅要求一阶矩的条件下就得到了:limn→∞max0≤k≤n∑k+[clogn]i=k+1Xi∑k+[clogn]i=k+1(X2i+1)=β(c),β(c)为某常数.众所周知,自正则下人们往往在较弱条件下取得相应结果是因为:分母中的X能有效抵销分子中X较大而引起整个分式极限行为的波动.因此,在什么样的条件下,式max0≤k≤n∑k+[clogn]i=k+1Xi∑k+[clogn]i=k+1X2i1-β[clogn]β→r(c)成为非常有意思的问题,因为它将依赖于β的大小.本文给出,当0<β≤12时,只要E(X)≥0,上式就有有限极限.当12<β<1时,则必须在矩母函数存在下,上式才有有限极限.并都求出了其极限表达式.  相似文献   

5.
MichaelBeals和GruyMetivier[1][2]在余法分布空间的框架下研究了多维高阶方程半线性波的反射问题,但文中均要求非线性自由项f不依赖于m-1u(m是方程的阶数).本文试图去除上述不自然的假定,运用的方法主要是定义了一类所谓三指标余法分布空间,发展了对非光滑系数拟微分算子的切向微局部分析,在两个互补的锥邻域内,分别利用奇性沿次特征线传播的有关定理和能量估计方法并依赖交换子技术来得出我们的结论.  相似文献   

6.
1 引言 设X是实的Banach空间,S   X是闭子集. 考虑下述多目标优化问题:其中fk,k∈N≡{1,…,n},gi,i∈M≡{1,…,m},hi,j∈P≡{1,…,p}均是定义在某开集(包含S)上的局部Lipschitz函数. 集合S0={x∈S:gi(x)≤0,i∈M,,hi(x)=0,j∈P}称为(VP)的可行解集.(VP)的局部有效解和局部弱有效解的定义见[2].设φ:X→R是局部Lipschitz函数,则 φ(x)称为φ在x处的Clarke广义梯度[3]. 关于非光滑多目标优化问题(V…  相似文献   

7.
OntheSolvabilityofx∈Ax+λBxinaGeneralCone withAandBMultivalued k-set-contractiveZhangQingyong(张庆雍)(DepartmentofMathematics,Sic...  相似文献   

8.
向量值Musielak-Orlicz空间的两种几何性质(英)   总被引:1,自引:0,他引:1  
设X是复Banch空间,M(t,u)是以t为参数的满足某些通常条件的Φ-函数.我们证明了;(i)Musielak-Orlicz空间L_M(X)具有解析UMD性质当且仅当X具有;(ii) L_M(X)具有解析RN性质当且仅当X具有.  相似文献   

9.
本文给出了四元数空间形式中全复子流形的一个性质.即设M2n是的全复子流形,ρ,‖Riem‖2,‖Ricci‖2分别表示M2n的纯量曲率和黎曼曲率,Ricci曲率的模长平方,则在M上处处成立.  相似文献   

10.
AMathematicalModelforEconomicRisk¥XuZegui(HenanInstituteofFinanceandEconomics,450002)Abstract:Basedontheanalysisforeconomicac...  相似文献   

11.
Ariyawansa and Felt (2001, 2004) have recently created a test problem collection for testing software for stochastic linear programs. This freely-available, web-based collection was originally created with 35 problem instances from 11 problem families representing a variety of application areas. The collection was created with plans for enriching it with problem instances based on different application areas from the research community. The work of Martel and Al-Nuaimi (1973) on manpower planning under uncertain demand represents an application area suitable for creating new problem instances to be added to the collection. The purpose of this paper is to describe the construction of a new family of stochastic programming test problems based on the work of Martel and Al-Nuaimi (1973). As part of our construction, we review the work of Martel and Al-Nuaimi (1973) leading to an extension of their models for which their solution procedure does not apply. The new test problems are based on this extension. We also present solutions to the test problems obtained using the software package CPA (2002) for stochastic programming developed by Ariyawansa, Felt and Sarich. Mathematics Subject Classifications (2000) 90C15, 90C90, 65K05. K. A. Ariyawansa: The work of this author was supported in part by the U.S. Army Research Office under Grant DAAD 19-00-1-0465.  相似文献   

12.
This note gives a survey on shared value problems for rational functions. In particular a solution to a problem in [A.K. Pizer (1973). A problem on rational functions. Amer. Math. Mon., 80, 552–553.] is given.  相似文献   

13.
We prove a limit theorem for the mathematical expectation of the solution of an initial value problem in a Hilbert space. The random differential equations considered here satisfy a strong mixing condition which is weaker than the one imposed in analogue results (Cogburn and Hersh, 1973; Papanicolaou and Varadhan, 1973). Our motivation to develop this analysis comes from a system (Nogueira, preprint) formed by coupling an external source to the Martin-Emch model (Martin and Emch, 1975).  相似文献   

14.
We examine a quasilinear boundary-value problem describing the dynamics of tidal flow in the sea. For small values of ground friction coefficient and under the fulfillment of a certain condition on the function giving the depth of the sea, we prove the existence of a generalized periodic solution. We construct a difference scheme for the numerical solution of the problem being examined and we prove its stability.Translated from Problemy Matematicheskogo Analiza. No. 4: Integralnye i Differentsial'nye Operatory. Differentsial'nye Uraveniya, pp. 3–9, 1973.  相似文献   

15.
Summary We prove the existence of a unique solution for a free boundary problem relative to the stationary flow between two water reservoirs of different levels separated by a dam of a non-homogeneous porous medium. Entrata in Redazione il 5 maggio 1973.  相似文献   

16.
We prove a sufficient condition for the solvability of a two-point problem.Translated from Matematicheskie Zametki, Vol. 13, No. 2, pp. 247–250, February, 1973.  相似文献   

17.
The problem of the rate of growth of the number of record values and weak record values in an iid sequence of integer valued random variables is attacked as a perturbation of the case for continuous random variables. Conditions in terms of either the underlying probability mass function or the hazard function of the underlying distribution are given for the rate of growth of the number of records to be log(n) almost surely. The record problem has been considered by Gouet et al.(2001) [Adv. Appl. Prob. 33, 473-864] and by Vervaat(1973) [Stochastic processes Appl. 1, 317-334]. The results for records overlap those found in the former paper. The methods here are more elementary, and the results on weak records are not mentioned there. This paper improves on what may be derived from results in Vervaat. (1973) [Stochastic Processes Appl. 1, 317-334] An erratum to this article can be found at  相似文献   

18.
The problem of agreement between two or more groups of judges has receivedconsiderable attention during the past decede, beginning with the papers by Schucany & Frawley (1973) and Hollander & Sethuraman (1978). Twovery different definitions of agreement have emerged in the literature. The first states that two groups of judges agree if they use the same probability distribution to select their rank vectors, while the second defines agreement In terms of correlation coefficients. We utilize the first definition in developing a new approach to solving this agreement problem, relying heavily on computer-generated tables  相似文献   

19.
We develop a stochastic multiplicative model for the forecasting of IBNR claims. The factor depending on the accident year is credibility adjusted.The title of this note also suits for the papers by Straub (1971) and Kramreiter and Straub (1973). We made stronger assumptions simplifying drastically the numerical calculations and the parameter estimation problem.As showed in the numerical illustrations, the developed method is also applicable in case of scarce irregular data.  相似文献   

20.
《Discrete Mathematics》2023,346(6):113349
The problem of reconstructing the characteristic polynomial of a graph of order at least 3 from the collection of characteristic polynomials of its vertex-deleted subgraphs was posed by Cvetkovi? in 1973 as a spectral counter part to the well-known Ulam's reconstruction conjecture. Over the last 50 years, this problem has received notable attention, many positive results have been obtained, but in the general case the problem is still unresolved. In particular, no counter example is found in literature. In this expository paper we survey classical and some more recent results concerning the polynomial reconstruction problem, discuss some related problems, variations and generalizations.  相似文献   

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