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报告题目: 数学在矿藏研究中的应用
报 告 人: Prof. Fun-Den Wang, Colorado School of Mines, USA
时间地点: 2009年11月11日上午9:00 S1013
摘       要:  
 
报告题目: On a degenerate free-boundary value problem arising from subsonic-sonic flows(系列报告04)
报 告 人: 辛周平教授 (香港中文大学)
时间地点: 2009年7月24日上午10:30 晨兴中心510室
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报告题目: Navier-Stokes方程边界形状控制和维数分裂算法
报 告 人: 黄艾香教授 (西安交通大学)
时间地点: 2009年7月13日下午4:00 思源楼1013室
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报告题目: Levenberg-Marquardt method and trust region method for nonlinear equations
报 告 人: 范金燕 教授 (上海交通大学)
时间地点: 2009年7月13日下午3:50 思源楼703室
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报告题目: Warehouse-Retailer Network Design Problem with Submodular Penalties: Heuristics and Bounds
报 告 人: 徐大川 教授 (北京工业大学)
时间地点: 2009年7月13日下午2:50 思源楼703室
摘       要:  
 
报告题目: Semismooth Newton methods for SVM
报 告 人: Prof.Hongxia Yin (Minnesota State University)
时间地点: 2009年7月13日下午2:00 思源楼703室
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报告题目: The report on basic scientific directions of Institute for system dynamics and control theory
报 告 人: Igor Bychkov院士 (俄罗斯科学院西伯利亚分院系统动力学与控制理论研究所所长)
时间地点: 2009年6月23日上午10:00 晨兴110室
摘       要:  
 
报告题目: Some Recent Progress on Switching Diffusion Systems (系列报告03)
报 告 人: Prof. G. Yin (Department of Mathematics Wayne State University)
时间地点: 2009年6月22日下午2:30 思源楼1013室
摘       要: In this talk, we report some of our recent work on switching diffusion processes in which continuous dynamics and discrete events coexist. With motivation from treating control and optimization of stochastic systems, we study stability problems. After recalling the notion of regularity and recurrence, necessary and sufficient conditions for positive recurrence will be provided; ergodicity will be examined; stability about an equilibrium point will be studied; rates of convergence of numerical algorithms for optimal control of switching diffusions will be mentioned.
 
报告题目: Nonlinear stability of traveling waves from conservation laws with higher order diffusion
报 告 人: Prof. Changbing Hu (University of Louisville, USA)
时间地点: 2009年6月18日下午4:00 思源楼703室
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报告题目: Special geometry and holomorphic anomaly Equations for generalized Calabi-Yau manifolds
报 告 人: 胡森 教授 (中国科学技术大学数学系)
时间地点: 2009年6月17日下午4:00 晨兴410室
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报告题目: 正曲率流形的分类问题
报 告 人: 朱熹平 教授 (中山大学)
时间地点: 2009年6月16日上午10:00 思源楼1013室
摘       要:  
 
报告题目: 正曲率流形的分类问题
报 告 人: 朱熹平 教授 (中山大学)
时间地点: 2009年6月16日上午10:00 思源楼1013室
摘       要:  
 
报告题目: On the uniqueness of invariant measure for stochastic delay equations
报 告 人: Prof. Michael Scheutzow (Technical University of Berlin, Germany)
时间地点: 2009年6月15日下午4:00 思源楼1013室
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报告题目: Three Types of Exact Tail Asymptotics for Random Walks in the Quarter Plane
报 告 人: Prof. Tao Luo (Georgetown University, USA)
时间地点: 2009年6月11日下午4:00 思源楼712室
摘       要: In this talk, I will present some results on the stability of rotating and non-rotating white dwarfs stars for the compressible Euler-Poisson equations, if the total mass is less than a critical mass. This is a joint work with Joel Smoller.
 
报告题目: Three Types of Exact Tail Asymptotics for Random Walks in the Quarter Plane
报 告 人: Dr. Yiqiang Q. Zhao (Carleton University, Canada)
时间地点: 2009年6月10日上午10:30 思源楼712室
摘       要: Random walks in the quarter plane can be viewed as a discrete time Markov chain with a two-dimensional state space. Under the stability condition, examples demonstrated that for a fixed value of one variable, the stationary tail probability as the other variable goes large decays according to three types: (a) exact geometric; (b) geometric with the subgeometric factor $n^{-3/2}$; and (c) geometric with the subgeometric factor $n^{-1/2}$. It is believed that these are the only types of tail asymptotics for any random walk in the quarter plane. Under some irreducible (or non-singular) conditions, this has been almost proved. In this talk, we discuss (i) why only these three types of tail asymptotics are expected; and (ii) other types may exist if the irreducible (or non-singular) condition does not hold. We also ask the question: are these three the only types of exact tail asymptotics for more general random walks, say random walks with jumps, assuming suitable irreducibility?
 
报告题目: 多点边值问题的多个变号解
报 告 人: 徐西安 教授 (徐州师范大学)
时间地点: 2009年5月27日上午11:00 思源楼712室
摘       要: 多点边值问题是近年非线性常微分方程研究领域的热点问题之一,其特殊情形包含了经典的两点边值问题。近年来人们较多地研究了多点边值问题正解和非平凡解的存在问题。研究多点边值问题变号解的存在性问题是个有意义的工作,存在一些新的困难。 报告人将介绍基于拓扑度和全局结构理论,特别是与上、下解结合寻找多点边值问题多个变号解的一些新方法。
 
报告题目: Convergence properties of solutions to several classes PDEs
报 告 人: Prof. Lei Zhang (University of Alabama at BirminghamSA)
时间地点: 2009年5月27日上午10:00 思源楼712室
摘       要: Many problems in Geometry, Physics and Biology are described by nonlinear partial differential equations of second order or four order. In this talk I shall mainly mention a class of fourth order equations from conformal geometry and some systems of second order equations with rich background in Physics and Ecology. These equations are challenging in analysis and represent some typical difficulties. There are some important open problems related to these equations and I will report the recent progress on these problems.
 
报告题目: Strong maximum principle for singular solutions of nonlinear elliptic equations
报 告 人: Professor Yanyan Li (Rutgers University, USA)
时间地点: 2009年5月25日上午10:00 思源楼1013室
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报告题目: Transformation Optics and Three Dimensional Cloaking of Active Devices
报 告 人: Professor Hongyu Liu (Dept of Mathematics, University of Washington, USA)
时间地点: 2009年5月22日下午4:00 思源楼1013室
摘       要: .In this talk, we shall first discuss the transformation optics in the design of cloaking devices to obtain customized electromagnetic wave propogation. Then, using the transformation optics, we give the construction of a three dimensional cloaking device, which makes the cloaked region with a source invisible to wave detection. Based on a new notion of "finite energy solution" for singular PDE, the rigorous mathematical justification of the invisibility cloaking is given. Finally, we briefly introduce a specially designed finite element discretization for numerically solving the cloaking problem
 
报告题目: Navier-Stokes equations in the critical Lebesgue spaces
报 告 人: 都大鹏博士 (复旦大学数学科学学院)
时间地点: 2009年5月21日下午4:00 思源楼1013室
摘       要: .
 
报告题目: Two-stage efficient estimation of stratified mark-specific proportional hazards models with missing marks(系列报告2)
报 告 人: Professor Yanqing Sun (University of North Carolina at Charlotte)
时间地点: 2009年2月10日下午4:00 思源楼712室
摘       要: Motivated by the need to assess HIV vaccine efficacy, the competing risks model with a continuum of competing risks, called mark, has been studied in recent years by a few authors. The mark-specific proportional hazards model is the proportional hazards model for mark-specific hazard function in which the regression parameters depend nonparametrically on the mark and the baseline hazard to depend nonparametrically on both time and mark. In the HIV vaccine efficacy trial, a very high percentage of marks of interest may be missing for infected trial participants due to the evolving nature of the HIV viruses. This research investigates the stratified mark-specific proportional hazards model with missing marks where the baseline functions may vary with strata. A two-stage estimation procedure is proposed. In the first stage, we propose an estimation procedure based on the inverse probability weighted complete-case technique. A more efficient augmented inverse probability weighted complete-case estimator is derived in the second stage based on the knowledge of the distribution of marks. In addition, the proposed two-stage procedure can utilize auxiliary information for missing marks to improve efficiency. The asymptotic properties of the proposed estimators are investigated. We show that the AUG estimator is more efficient than the IPW estimator. The finite sample performance of the proposed methods are evaluated through simulations. The applications to the HIV vaccine efficacy assessment are discussed .
 
报告题目: Jackknife empirical likelihood(系列报告1)
报 告 人: Professor Bing-Yi JING (Hong Kong Univ. of Science & Technology)
时间地点: 2009年1月7日下午4:00 思源楼703室
摘       要: Empirical likelihood, since its first introduction by Owen in 1988, has been found very useful in many different occasions. However, it is not always trouble-free. For instance, when applied directly to some more complicated statistics such as U-statistics, it runs into serious computational difficulties, particularly when the sample size gets larger. In this paper, we will take a fresh look at the problem. We introduce a new approach which combines two of popular nonparametric approaches: the jackknife and the empirical likelihood. The resulting method, referred to as the jackknife empirical likelihood (JEL), is extremely simple to use in practice, in comparison with other existing methods. In particular, the new method is shown to be very effictive in handling U-statistics. The JEL can be potentially useful for other nonlinear statistics, however, further research is needed to justify its usage in those situations.
(This is joint work with Junqing YUAN and Want ZHOU.) .
 
报告题目: Quasi-Likelihood of Models: Modified Profile Likelihood for Model Selection
报 告 人: Dr. He Heping (The University of Kansas )
时间地点: 2009年1月5日下午3:00 思源楼703室
摘       要: The goal of this research is to develop the modified profile likelihoods (MPLs) as quasi-likelihood functions of models for model selection. It treats those parameters in each possible model as nuisance parameters, and the models themselves as the values of the ``parameter'' of interest, then uses the likelihood ratio approximation to conditional distribution of maximum likelihood estimators of the parameters in the possible models to develop the MPLs of models. Note that the MPL proposed here is considered as a function of models themselves instead of parameters in the models. The selected model is then the one maximizing the quasi-likelihood of models, i.e. the MPL. Some simulations have show that the MPL works very well for the selection of error probability laws in location-scale models. The MPL of models has also been obtained for composite transformation models. In future, this research may develop the MPL of models for model selection problems in exponential family, regular models, regressions, change point problems, AR or ARMA time series models and so on.
 
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