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COLLECTIVELY COMPACT COMPOSITION OPERATOR SEQUENCES BETWEEN BERGMAN AND HARDY SPACES

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Acta Mathematica Scientia 2004年第2期24卷 206-212页

作者：王茂发刘培德 schoolofmathematicsandstatistics WuhanUniversityWuhan430072China

This paper studies the collective compactness of composition operator sequences between the Bergman and Hardy spaces. Some sufficient and necessary conditions involving the generalized Nevanlinna counting functions fo... 详细信息

关键词： Bergman space Hardy space composition operator collectively compact operator sequence

An Improved Moving Mesh Algorithm

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Wuhan university Journal of Natural Sciences 2001年第4期6卷 764-766页

作者： Cheng Jian,Sun Le lin,Xu Di hong school of mathematics and statistics, Wuhan university,Wuhan 4.0072,{4. Wuhan university School of Mathematics and Statistics Wuhan China (GRID:grid.49470.3e) (ISNI:***)

We consider an iterative algorithm of mesh optimization for finite element solution, and give an improved moving mesh strategy that reduces rapidly the complexity and cost of solving variational problems. A numerical ... 详细信息

关键词： adaptive method moving mesh method variational problem

Jackknifed random weighting for Cox proportional hazards model

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Science china mathematics 2012年第4期55卷 775-786页

作者： LI Xiao 1 ,WU YaoHua 2,& TU DongSheng 1 1 Cancer Research Institute,Queen’s university,Kingston,Ontario K 7L 3N6,Canada 2 Department of finance and statistics,university of Science and Technology of {4.,Hefei 230026,{4. 1. Cancer Research Institute Queen’s University Kingston Ontario K7L 3N6 Canada2. Department of Finance and Statistics University of Science and Technology of China Hefei 230026 China

The Cox proportional hazards model is the most used statistical model in the analysis of survival time ***,a random weighting method was proposed to approximate the distribution of the maximum partial likelihood estimate for the regression coefficient in the Cox *** method was shown not as sensitive to heavy censoring as the bootstrap method in simulation studies but it may not be second-order accurate as was shown for the bootstrap *** this paper,we propose an alternative random weighting method based on one-step linear jackknife pseudo values and prove the second accuracy of the proposed *** Carlo simulations are also performed to evaluate the proposed method for fixed sample sizes.

关键词： Cox proportional hazards model jackknife random weighting second-order accuracy simulations survival data

A LAW OF ITERATED LOGARITHM FOR THE MLE IN A RANDOM CENSORING MODEL WITH INCOMPLETE INFORMATION

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Acta Mathematica Scientia 2008年第3期28卷 501-512页

作者：宋凤丽刘禄勤 school of mathematics and statistics Wuhan University

In this article, a law of iterated logarithm for the maximum likelihood estimator in a random censoring model with incomplete information under certain regular conditions is obtained.

关键词： Random censoring model maximum likelihood estimator law of iterated logarithm

Synchronization of Unified Chaotic System Using Occasional Driving

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Wuhan university Journal of Natural Sciences 2003年第3A期8卷 808-812页

作者： Wu Xiao\|qun, Lu Jun\|an  school of mathematics and statistics, Wuhan university , Wuhan 4.0072, Hubei, {4. Wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The synchronization of the unified chaotic systems using occasional driving technique is studied. The relation among interim period T , sampling interval 2 ε , feedback gain r and the parameter α of the system is thoroughly investigated. Numerical results show that smaller interim period T and properly larger sampling interval 2 ε can accelerate the synchronizing pace. Furthermore, for a unified chaotic system in which α is given, we can achieve satisfying synchronizing results as long as T,ε and r are appropriately chosen. As we adopt the occasional driving method, we greatly reduce the control cost. Therefore with this method we can obtain the expecting goals with little control cost.

关键词： synchronization occasional drive unified chaotic system

ANALYSIS OF LIMIT CYCLES TO A PERTURBED INTEGRABLE NON-HAMILTONIAN SYSTEM

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Annals of Differential Equations 2012年第3期28卷 263-268页

作者： Xiaochun Hong1,2,Yunqiu Wang1,Xuemei Zhang2 1.school of statistics and Math.,yunnan university of {4. and Economics,Kunming 650221 2.school of Math.and Information Science,Qujing Normal university,Qujing 655011,yunnan

Bifurcation of limit cycles to a perturbed integrable non-Hamiltonian system is investigated using both qualitative analysis and numerical *** investigation is based on detection functions which are particularly effective for the perturbed integrable non-Hamiltonian *** study reveals that the system has 3 limit *** the method of numerical simulation,the distributed orderliness of the 3 limitcycles is observed,and their nicety places are *** study also indicates that each of the 3 limit cycles passes the corresponding nicety point.

关键词： limit cycle integrable non-Hamiltonian system detection function numerical exploration

Large-deviation probabilities for maxima of sums of subexponential random variables with application to finite-time ruin probabilities

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Science china mathematics 2008年第7期51卷 1257-1265页

作者： JIANG Tao school of finance,Zhejiang Gongshang university,Hangzhou 310018,china 1. school of finance Zhejiang Gongshang University Hangzhou 310018 China

We establish an asymptotic relation for the large-deviation probabilities of the maxima of sums of subexponential random variables centered by multiples of order statistics of *** uniform random *** extends a corresponding result of *** an application,we generalize a result of Tang,the uniform asymptotic estimate for the finite-time ruin probability,to the whole strongly subexponential class.

关键词： large-deviation probability strongly subexponential distribution finite-time ruin probability the compound Poisson model uniform asymptotics 91B30 60G70 62P05

A Necessary Condition on Comparison Theorem for One-Dimensional Stochastic Differential Equation

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Wuhan university Journal of Natural Sciences 2010年第1期15卷 13-15页

作者： ZHAO Shoujiang,GAO Fuqing school of mathematics and statistics,Wuhan university,Wuhan 4.0072,Hubei,{4. school of mathematics and statistics Wuhan University Wuhan China

We consider the comparison theorem of one-dimensional stochastic differential equation with non-Lipschitz diffusion coefficient. Considering the two one-dimensional stochastic differential equations as a two-dimension... 详细信息

关键词： comparison theorem Ito formula necessary condition

Existence of Equilibrium Solutions to a Size-Structured Predator-Prey System with Functional Response

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Wuhan university Journal of Natural Sciences 2009年第5期14卷 383-387页

作者： LIU Keying,LIU Weian school of mathematics and statistics,Wuhan university,Wuhan 4.0072,Hubei,{4. school of mathematics and statistics Wuhan University Wuhan 430072 Hubei China

In this paper, we consider a nonlinear size-structured population model with functional response, which describes the dynamics of a predator-prey system living in a common habitat. We present a kind of functional response for the prey being a plant or algae, and explain its biological meanings. When the vital rates depend both on the individual＇s size and on the total population or only depend on the former, we obtain the existence of equilibrium solutions.

关键词： equilibrium solutions functional response predator- prey system size-structured population model