We consider a class of delayed bidirectional associative memory (BAM) neural networks. Linear stability of the model is investigated by analyzing the associated transcendental characteristic equation. By means of the symmetric bifurcation theory of delay differential equations coupled with representation theory of standard dihedral groups, we not only investigate the effect of synaptic delays of signal transmission on the pattern formation, but also obtain some important results about the spontaneous bifurcation of multiple branches of periodic solutions and their spatiotemporal patterns. Based on the normal form approach and the center manifold theory, we derive the formula to determine the bifurcation direction and stability of Hopf bifurcated periodic solutions. These theoretical results are important to complement the experimental and numerical observations made in living neurons systems and artificial neural networks, in order to better understand the

报告人：Ken-Ichi Nakamura(The University of Electro-Communications, Japan)题目：Dynamics of fronts in a reaction-diffusion equation of multistable type时间：2009年3月17日（星期二），下午4:00-5:00地点：数学系致远楼105欢迎各位参加

本报告主要介绍李共形代数的定义和一些例子、李共形代数与形式分布李代数的对应关系以及李共形代数的表示与形式分布李代数的表示的对应关系。然后给出一般共形李代数gc_n的上同调。最后讲述如何将某些李代数表示理论的问题转化为李共形代数的相应问题。

(1) Positive Linear Maps on Matrix Algebras --Sums of squares with quantum information.(2) Non-commutative Magic Everywhere.(3) Normal Dilations.Reporter：Professor Man-Duen Choi (加拿大皇家科学院院士蔡文端先生) University of TorontoCanadaTime： 14：30 Mar. 30, Apr. 3, Apr. 6, 2009Place： Room 107, Zhiyuan Building Tongji University, Shangha

报告人：中国科学院数学研究所孙笑涛教授题 目：模空间上的极小有理曲线时 间：2009年4月10日星期五下午4:00-5:00地 点：数学系致远楼107室热烈欢迎各位参加

报告人：董光昌教授（浙江大学数学系）题目： 素数漫谈时间：2009年4月30日(星期四) 下午3：30—4：30地点：数学系致远楼107欢迎各位参加

题 目：关于复多项式 Fermat 大定理的一个初等证明报告人：西南大学郭聿琦教授时 间：五月二十五日（星期一）16：00-17：00地 点：致远楼107室欢迎大学生和研究生参加

题目: Cooperative Distributed Information Processing and Control for Networked Systems报告人: Lihua Xie, IEEE Fellow，Professor of Nanyang Technological University, Singapore时间: 5月26日（周二）10：35地 点: 嘉定校区电信楼309欢 迎 参 加！2009-5-15Abstract of the talk….Networked systems have attracted resurgent interest in recent years. Particular attentionhas been devoted to wireless sensor ne...