演讲人: Peijun Li, Purdue University

讲座时间: 2013年6月26日（周三）下午3：00-4：30

讲座地点: 信息楼4楼报告厅

讲座内容:

报告摘要： This talk is concerned with an inverse surface scattering problem in near-field optical imaging, which is to reconstruct the scattering surface with a resolution beyond the diffraction limit. The surface is assumed to be a small and smooth deformation of a plane surface. Based on a transformed field expansion, the boundary value problem with complex scattering surface is converted into a successive sequence of a two-point boundary value problems in the frequency domain, where an analytic solution for the direct scattering problem is derived from the method of integrated solution. By neglecting the high order terms in the asymptotic expansion, the nonlinear inverse problem is linearized and an explicit inversion formula is obtained. The method works for sound soft, sound hard, and impedance surfaces, and requires only a single illumination at a fixed frequency and is realized efficiently by the fast Fourier transform. Numerical results show that the method is simple, stable, and effective to reconstruct scattering surfaces with subwavelength resolution.

报告人简介：

李培军教授1998年在武汉大学获理学学士学位，2001年在中科院计算数学所获理学硕士学位，2005年在美国密西根州立大学获理学博士学位。之后，他曾在密西根大学做博士后研究，2008-2013在普渡大学任助理教授，2013至今任副教授。李培军教授的主要研究领域是电磁场计算与偏微分方程反问题，目前他发表学术论文30余篇，其中20余篇在本领域国际顶尖杂志上。曾获NSF的多次资助和三个奖项：

l NSF Faculty Early Career Development (CAREER) Program，2012（相当于美国的杰出青年自然科学基金，当年计算数学领域仅此一个）；

l NSF Highlight:Creating Better Near-field Optical Devices, 2012，美国自然科学基金委网站公布的突出研究成果：Creating Better Near-field Optical Devices；

l Paul & Wilma Dressel 奖, 密西根州立大学，2004