Petri nets are a powerful formalism in modeling workflows. A workflow determines the flow of work according to pre-defined business process definitions. In many situations, business processes are constrained by scarce resources. The lack of resources can cause contention, the need for some tasks to wait for others to complete, and the slowing down of the accomplishment of larger goals. In our previous work, a resource-constrained workflow model is introduced and a resource requirement analysis approach is presented for emergency response workflows, in which support of on-the-fly workflow change is critical. This presentation discusses a Petri net based approach for recourse requirements analysis, which can be used for more general purposes. The concept of resource-oriented workflow nets (ROWN) is introduced and the transition firing rules of ROWN are presented. Resource requirements for general workflow can be done through reachability analysis. For a class of well-structured workflows

The spread of many infectious diseases can be modeled by mathematical equations according to certain idealized physical laws. The physical laws are described in terms of parameters. The basic reproduction number (R0) is an important concept in studying the transmission and control of infectious diseases which is defined as the expected average number of secondary cases produced by an index case during its infectiousness period. Roughly speaking, a disease can be controlled or even can die out if R0<1; it spreads out or becomes endemic if R0>1. Mathematical modeling and analysis plays a crucial role in evaluating R0 in terms of model parameters and understanding the spread of the diseases. In this talk, we will introduce some basic epidemic models and some recent work on modeling hepatitis B virus, schistosomiasis, and rabies in China

报告人：藕彪教授（University of Toledo, Ohio, USA）题目： On a mathematical model for irrotational fluid flows around a body in space时间：2012年5月23日(星期三)上午10：00—11：00地点：数学系致远楼102欢迎各位参加

伴随着信息技术，特别是计算技术的飞速发展，科学计算已经渗透到几乎所有科学研究领域，形成了众多的计算科学分支；并且随着工程科学计算及模拟仿真技术的系统化和集成化，发展成为数字工程。应用数学和计算数学是它们的共性基础；同时，它们也是应用数学和计算数学发展的广阔天地，科学问题的发源地，研究成果的落实地。 本报告将从如下方面，简述相关领域的发展现状、趋势，以及相关的应用数学和计算数学问题： • 飞速发展的信息技术 • 科学计算 科学计算无处不在、科学计算的内涵、迅速发展中的计算科学 案例—（1）材料物性研究中的几个科学计算问题 （2）面向千万到万万亿次、大规模多核计算机的科学计算 • 数字工程 现代工程中的几个科学计算问题、 CAD/CAM/CAE/CAI、集成化信息技术、案例 • 为繁荣中国的科学计算和数字工程而奋斗

In contrast to other nonparameteric regression techniques, smoothing parameter selection for spline estimators can be performed not only by employing criteria that approximate the average mean squared error (e.g. generalized cross validation), but also by making use of the maximum likelihood (or empirical Bayes) paradigm. In the later case, the function to be estimated is assumed to be a realization of some stochastic process, rather than from a certain class of smooth functions. Under this assumption both smoothing parameter selectors for spline estimators are well-studied and known to perform similar. A more interesting problem is the properties of smoothing parameter estimators in the frequentist framework, that is if the underlying function is non-random. In this talk we discuss the asymptotic properties of both smoothing parameter selection criteria for general low-rank (or so-called penalized) spline smoothers in

报告人： Professor Li Deli(加拿大Lakehead大学数学科学系教授）报告(一)题目：On the Central Limit Theorem along Subsequencesof Sums of Independent Random Variables(独立随机变量子序列的中心极限定理)时间：2012年5月25日（周五）下午 4:00开始报告(二)题目：A Comparison Theorem for the Law of LargeNumbers in Banach Spaces(Banach空间关于大数定律的比较定理)时间：2012年5月31日（周四）上午9:00开始地点：数学...

报告人：杨启帆教授（浙江大学）题目： 从数学建模看数学教育在人才培养中的作用时间：2012年5月21日，星期一上午10：00—11：00地点：数学系致远楼107欢迎各位参加

数学系（致远楼）107 欢迎广大师生参加 数学系、数学所 摘要： Given a vector space, its affinization is the direct sum of its negative, positive and zero parts. I recently found that on the tensor algebra of the negative part of the affinization, there is an algebraic structure satisfying the axioms for open-string vertex algebras (algebras introduced by Kong and me in 2004) and also an additional meromorphicity property. I call such an algebra a meromorphic open-string vertex algebra. A meromorphic open-string vertex algebra does not satisfy the Jacobi identity, the commutator formula, locality, commutativity, skew-symmetry or even the associator formula. But it still satisfies the most fundamental property for a quantum field theory: the existence of operator product expansion. In fact, it satisfies associativity, a stronger property implies the operator product expansion