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1.
基于二项分布随机增长的无标度网络   总被引:1,自引:0,他引:1  
陈琴琴  陈丹青 《数学研究》2010,43(2):185-192
提出—个具有随机增长的无标度网络模型.该模型的演化规则仍然是BA模型的增长和择优连接,但是每一时间间隔添加到网络中的边数是—个具有二项分布的随机变量.通过率方程方法,本文证明了该网络的度分布具有幂律尾部,该模型生成了—个无标度网络.  相似文献   

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随机Gilpin-Ayala竞争模型的稳定性   总被引:2,自引:0,他引:2  
本文主要研究了一类随机Gilpin—Ayala竞争模型,它比经典Lotka—Volterra竞争模型更具一般性和实际意义.通过应用M矩阵的性质,得出随机Gilpin—Ayala竞争模型的稳定性的一些结论。  相似文献   

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笔者有幸执教了一节“全等三角形”复习的公开课,根据本节内容在课标、考纲中的要求,把教学重点确定为全等三角形的性质及判定方法和全等三角形的模型图,难点为全等三角形模型图与旋转法的应用.教学环节有:考点解读—要点回顾—常考点剖析—观察与发现—提炼模型—反思归纳—解决问题—课堂小结—布置作业.  相似文献   

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基于条件VaR(CVaR)的投资组合优化模型及比较研究   总被引:6,自引:0,他引:6  
在总结投资组合优化模型的基础上 ,详细分析了 Va R和 CVa R的概念及重要性质 ,分析了将 Va R和 CVa R应用于决策问题的处理技巧 .针对传统均值—方差模型 ,提出不考虑各种限定条件的基于条件Va R( CVa R)的投资组合优化模型以及考虑限定条件的一般模型 .针对模型的适用性 ,详细比较了 CVa R模型和均值—方差模型的应用复杂性 ,并利用实际数据进行了对比 .  相似文献   

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运用博弈论中委托—代理理论对股权—债权条件下风险投资的激励机制进行了系统分析.根据风险投资家提供股权—债权与风险企业家提供股权融资的假设条件构造了一个基本博弈模型,并对模型进行了推广.研究发现:风险企业家的投资不仅有融资功能,而且还可以作为一种信号传递改变风险投资家的投资信念,使之对项目前景更乐观;扩展模型比基本模型更能改善风险企业家的投资行为,使之投入更多资金和给予风险投资家更高激励;此外,扩展模型更能消除股权—债权投资比例的相互替代性.  相似文献   

6.
几类Lotka-Volterra模型的定性分析   总被引:1,自引:0,他引:1  
本文考虑几类“捕食者—食饵”型的Lotka—Volterra模型,给出了这些模型全局稳定与所有正解最终有界的充分条件;对这些条件的描述与论证,本文运用了图论的概念与方法。  相似文献   

7.
本文首先一般化了可中断的概念,并建立了相应的中断—安装重复模型,然后研究了单机排序问题1|rj,prmp| wj(1-e-acj)在中断—重复和中断—安装重复模型下的动态在线排序问题,给出了只考虑当前可用信息而不是考虑全部任务信息的在线调度规则。  相似文献   

8.
利用Black—Scholes偏微分方程,结合重置期权与关卡期权的关系,建立了规定水平下的重置期权定价模型,最后运用C—N格式和θ法构造该模型的有限差分格式.  相似文献   

9.
本文给出了人民币汇率决定模型,并对货币供需、资金流量进行了分析.该模型参照了Robimson的国际贸易条件理论、Alexander吸收理论、特别是Barro—Calvo—Robriguez融资产组合平衡与货币分析法于一体的货币主义的货币替代模型.这个模型体系由三部分组成:基本模型、动态模型、调控模型.基于这三个模型,对汇率决定进行了一般的均衡分析、走势分析与调控分析.  相似文献   

10.
(一) 本世纪三十年代末期到四十年代中期、英国牛津大学教授哈罗德(R·H·Harrod)和美国经济学家、麻省理工学院的多马(E·D·Domar)分别独立地提出了一种建立在宏观分析基础之上的经济增长理论,这种理论试图将凯恩斯的经济学说用于说明发展中国家的经济增长问题,而其分析问题的方法则由凯恩斯短期、静态的分析转向长期、动态的分析. 最能概括哈罗德——多马经济增长理论的是他们各自建立的增长模型,由于这两个模型异曲同工,后来被人们统称为“哈罗德——多马”模型. 哈罗德——多马模型采用凯恩斯储蓄——投资的分析方法,考察了三个经济…  相似文献   

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We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.  相似文献   

13.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

14.
It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.  相似文献   

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正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   

17.
正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.  相似文献   

18.
A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].  相似文献   

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