依理学之鸿蕴，展信息之魅力，由理学院和信息学院博士生会承办的浙江大学第四届博士生创新论坛之信理or信息分论坛已经在进行当中。通过前期的征文活动我们收到很多优秀的博士生论文，从这些论文中我们评选出两篇，邀请两位优秀博士生为我们做报告，欢迎大家参加。
时间 2007年5月29日 1900
地点 玉泉校区数学中心202室
报告内容简介

(1) 《光纤环谐振曲线振铃现象特性分析》

应迪清 博士 浙江大学信息与电子工程系，微电子与固体电子学

摘要： 谐振式光纤陀螺是利用光纤环的Sagnac效应实现对转动角速度检测的一种高精度的惯性传感器件。光纤环形谐振腔是谐振式光纤陀螺的核心敏感部件。运用光场叠加原理，对扫频实验中观测到的光纤环谐振频谱振铃现象的产生进行理论推导及解释，通过计算机仿真分析结果，得到结论，扫频速度过快会直接引起多光束最佳相消干涉不同时，也会导致直通端光场与从光纤环出射光场的干涉在最佳相消干涉与最佳相长干涉之间来回波动，从而产生振铃现象。

(2) 《An Algorithm for Solving the Double Obstacle Problems》

王飞 博士 浙江大学数学系 计算数学专业

The obstacle problem is typical elliptic variational inequality of the first kind, it is not just only introduced for a membrane in elasticity theory, but also for the non-parametric minimal and capillary surfaces as geometrical problems. The elastic-plastic torsion problem and the cavitation problem in the theory of lubrication also can be regarded as obstacle type problems. Since the obstacle problem is highly nonlinear, the approximated solution is difficultly computed. The usual method for solving obstacle problems is variable projection method, such as the relaxation method, multilevel projection method, multigrid method and so on. The authors in An Algorithm for Solving the Obstacle Problems propose an algorithm, whose process is similar to simulating of moving obstacle but not same, to find the approximatedregion of the contact. In this paper, we extend this algorithm for solving the double obstacle problem. We try to find the approximated region of the contact in the double obstacle problemwith less computation time by iteration. Numerical example is given for the doubleobstacle problem for the elastic-plastic torsion problem to support the algorithm.