题目：A multilevel sampling algorithm for locating inhomogeneous media

报告人：刘可伋， 上海财经大学

时间： 上午10:30-11:30, 2017.07.04

地点：理科楼407

摘要：

In the reconstruction process of unknown multiple scattering objects in inverse medium scattering problems, the first important step is to effectively locate some approximate domains that contain all inhomogeneous media. Without such an effective step, one may have to take a computational domain of a size that is much larger than the actual sizes of all scattering objects, thus resulting in huge additional computational effort. In this work, we propose a simple and efficient multilevel reconstruction algorithm to help locate an accurate position and the shape of each inhomogeneous medium. Then, other existing effective but computationally more demanding reconstruction algorithms may be applied in these initially located computational domains to achieve more accurate locations and shapes of the scatterer and the contrast values over each medium domain. The new algorithm exhibits several strengths: robustness against noise, requiring fewer incidences, fast convergence, flexibility to deal with scatterers of special shapes and advantages in computational complexity. 

报告人简介：刘可伋，上海财经大学副教授，毕业于香港中文大学，主要从事反散射问题及金融投资策略研究。曾获得上海市“浦江人才”计划及“晨光学者”计划支助，目前主持国家自然科学基金一项，在SIAM J. Sci. Comp.，Inverse Problem等国际SCI期刊上发表多篇论文。