学术报告报告人:章梅荣(清华大学数学系)题目：非退化位势与非线性微分方程解集合的结构时间：2014年9月19日(星期五)上午9：00—10：00地点：致远楼102欢迎各位老师和参加

学术报告报告人:舒洪颖题目：Global dynamics on viral dynamics时间：2014年9月19日(星期五)上午10：00—11：00地点：致远楼102欢迎各位老师和学生参加

Gesture recognition allows users to communicate with the machines more naturally without any mechanical devices such as keyboards or mouse. It can be conducted with techniques fromcomputer visionandimage processing. Input devices include wired gloves, stereo cameras and controller-based gestures. Leap Motion Controller is a new device that is capable of tracking all ten of one’s fingers individually and handling movements with high speed and accuracy. This presentation will introduce gesture recognition algorithms, challenges and potential applications. Leap Motion Controller based hand gesture applications will be demonstrated.

Starting from two expressions of the famous Kostka polynomial, I explain how to generalize this equality in full generality for so called type A with the aid of the crystal basis theory and to prove it in a combinatorial manner. I then extend the equality, though it is still a conjecture (X=M conjecture), to all affine root systems. Finally, I give a sketch of proof for settled cases.

主要介绍多重网格法和区域分解法，以及它们的应用。

学术报告报告人：徐洪坤教授（第三世界科学院院士，台湾中山大学西湾讲座教授）题目: The lasso: Variants and Iterative Methods时间：2014年9月10日(星期三) 下午4：00—5：00地点：数学系致远楼102欢迎各位参加

As shown in classical linear system theory, the behavior of a linear system is determined by its intrinsic structure, but this connection for nonlinear systems has not been clearly identified and utilized. On the contrary, the intrinsic nonlinear structures of a system are indeed often ignored or even destroyed by linearization or feedback linearization methods. Recently, the success of homogeneity based approaches in designing state and output feedback stabilizers has led to renewed interests in this theory. This talk will sketch the recent efforts in revitalizing and advancing homogeneous system theory for analyzing nonlinear characterizations and designing nonlinear controllers. The specific topics will cover: homogeneity based approaches such as adding a power integrator and homogeneous domination approach for output feedback control;

This lecture will present some new results on global stabilization by output feedback for nonminimum-phase nonlinear systems of a cascade configuration that consists of a driven system (inverse dynamics) and a driving system. Although the zero dynamics may be unstable, there exists an output feedback control law, globally stabilizing the nonlinear system, if both the driven and driving systems have a triangular form and satisfy a global Lipschitz-like condition, and the inverse dynamics is input-to-state stabilizable. A controller design algorithm, examples and simulation results are presented to demonstrate the control strategy and its effectiveness. Discussion will be given on control of nonminimum-phase nonlinear systems, a challenging and important open research topic.