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Philippe Carmona Francesco Guerra Yueyun Hu Olivier Mejane 《Journal of Theoretical Probability》2006,19(1):134-151
We study a model of directed polymers in a random environment with a positive recurrent Markov chain, taking values in a countable space Σ. The random environment is a family () of independent and identically distributed real-valued variables. The asymptotic behaviour of the normalized partition function is characterized: when the common law of the g(·,·) is infinitely divisible and the Markov chain is exponentially recurrent we prove that the normalized partition function converges exponentially fast towards zero at all temperatures. 相似文献
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研究了在环境平稳遍历时,右半直线上可逗留的随机环境中的随机游动的常返性和非常返性,给出非常返、正常返、零常返的充要条件,并讨论了极限性质.作为推论,给出P独立同分布时的相应结论. 相似文献
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This paper proposes and analyzes a class of multigrid smoothers called the parallel multiplicative (PM) smoother by subspace decomposition techniques. It shows that the well known additive and multiplicative smoothers and the JSOR smoother are special cases of the PM smoother, and their smoothing properties can be obtained directly from the PM analysis. Moreover, numerical results are presented in this paper to show that the JSOR smoother is more robust and effective than the damped Jacobi smoother on current MIMD parallel computers.
AMS subject classification (2000) 65N55, 65Y05.Received May 2004. Revised September 2004. Communicated by Per Lötstedt.Dexuan Xie: This work was partially supported by the National Science Foundation through grant DMS-0241236. 相似文献
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一类Leslie模型的定性分析 总被引:2,自引:0,他引:2
对一类Leslie模型进行定性分析,研究了其极限环的存在性,不存在性和唯一性.证明了该系统在细焦点外围至多有一个极限环,以及如果系统有奇数个极限环,则它恰有一个极限环. 相似文献
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Mathematical Notes - The asymptotic behavior of the survival probability for multi-type branching processes in a random environment is studied. In the case where all particles are of one type, the... 相似文献
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刘铎 《数学的实践与认识》2006,36(11):123-128
从组合学的角度研究了一类随机选取集合中元素的覆盖问题,得到了重复性地、随机独立地、等概地选取某个有限集合中的元素,不遗漏地取遍所有元素所需的次数的期望,给出了理论和实验的数据结果.并且分析了该问题在现实世界中的一些实例.而且对于该问题的扩展模型—每次抽取集合中t个不同元素—进行了一些探讨. 相似文献
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§1. IntroductionIn1984,thearticle[1]studiedthefollowingautocatalyticreactionsmodeldadt=-k1ab2+kf(a0-a)dbdt=k1ab2-k2b-kf(b-b0)(1)wherek1,k2,kf,a0,b0areallpositivearbitraryconstants.Thearticlepointsouttheremaybeninephase-portraitsinsystem(1).Ithasnotgi… 相似文献
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研究了一类环境污染相关的二维时滞微分方程动力学模型平衡点的稳定性与Hopf分支周期解的存在性,利用LaSalle不变性原理证明变界平衡点E_0在条件n-m≥a时是全局渐近稳定的;同时,给出正平衡点产生Hopf分支的充分条件。最后,数值模拟验证了理论结果。 相似文献
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<正>Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for a rectangular domain that exhibits interesting symmetry properties.We also demonstrate the procedure for performing a center manifold reduction on the system to extract a set of coordinates which capture the long term dynamics when the system is close to a bifurcation.Bifurcations of the system restricted to the center manifold are then classified and compared to numerical results.Although we analyze a specific set-up,these methods can in principle be applied to any bifurcation point of any equilibrium for any domain. 相似文献
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对一类五次平面多项式微分系统进行了定性分析.给出原点的中心与等时中心条件及极限环的存在性.研究了此系统无穷远点的性态,该无穷远点是高次奇点,并运用把大角域分为若干小角域的方法对此高次奇点在不定号情形下轨线的分布情况进行讨论. 相似文献
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本文研究一类可逆生化反应的数学模型 :dxdt=a-( b+1 ) x+x2 y-cx3,dydt=bx-x2 y+cx3.应用微分方程定性理论 ,完整地解决了该系统极限环的存在性、唯一性和不存在性等问题 . 相似文献
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在弱平稳α-混合样本下利用概率密度函数的核估计构造了伽玛分布族参数的经验Bayes(EB)检验函数,并获得了它的渐进最优(a.o.)性.在适当的条件下证明了所提出的EB检验函数收敛速度可任意接近O(n~(-1/2)). 相似文献
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Hong-yong Wang Zong-ben XuDepartment of Mathematics Huaibei Coal Industry Teachers College Huaibei ChinaResearch Center for Applied Mathematics Faculty of Science Xi''''an Jiaotong University Xi''''an China 《应用数学学报(英文版)》2002,18(3):431-440
In this paper, we construct a class of nowhere differentiable continuous functions by means of the Cantor series expression of real numbers. The constructed functions include some known nondifferentiable functions, such as Bush type functions. These functions are fractal functions since their graphs are in general fractal sets. Under certain conditions, we investigate the fractal dimensions of the graphs of these functions, compute the precise values of Box and Packing dimensions, and evaluate the Hausdorff dimension. Meanwhile, the Holder continuity of such functions is also discussed. 相似文献
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本文考虑二阶非线性系统x″( t) +f( x′( t) ) +g( x( t) ,x′( t) ) φ( x( t-τ) ) =p( t) .我们借助于李雅普诺夫第二方法 ,得到了其运动稳定性、有界性、周期解的存在性和平稳振荡的存在性等方面的四个结论 ,并推广了有关文献中的结果 相似文献