（一）报告题目:Forward and inverse wave scattering from axisymmetric objects based on integral equations

            报告人:赖俊 浙江大学 时间：5月26日14:00

（二）报告题目：Study of bioluminescence tomography based on a new coupled diffusion equations

            报告人:龚荣芳  南京航空航天大学教授  时间: 5月26日 15:00

主办单位：数学与统计学院

报告地点：腾讯会议：125-573-726

（一）摘要:Fast, high-accuracy algorithms for electromagnetic and elastic scattering from axisymmetric objects are of great importance for modeling physical phenomena in optics, materials science (e.g. meta-materials), and many other fields of applied science. In this talk, we develop an FFT-accelerated separation of variables solver that can be used to efficiently invert integral equation formulations of Maxwell's equations and Navier equations for scattering from axisymmetric bodies. The solver is also extended to geometries with non-smooth generating curves and large cavities. In the end, we also discuss the application of the fast and high-order solver in the inverse scattering to recover the objects with axis-symmetry.

报告人简介: 赖俊，南京大学数学系本科，美国密西根州立大学应用数学博士毕业，曾任纽约大学柯朗数学研究所博士后及讲师（Courant Instructor），目前任浙江大学数学科学学院研究员，主要研究声波，电磁波及弹性波方程的散射与反散射问题，在数学知名杂志ACHA，SISC，Math Comp，Inverse Problems等发表文章多篇，主持国家面上项目，并参与基金委重大研究计划，基金委创新群体等研究，曾入选中组部高层次青年人才计划，获十一届全国反问题年会“优秀青年学术奖”。

（二）摘要：In this talk, we consider inverse source problems arising in bioluminescence tomography (BLT). Mathematically, BLT is an under-determined inverse source problem which leads to no solution uniqueness. Particularly, one cannot distinguish between a strong source over a small region and a weak source over a large region. Therefore, it is particularly important to know the support $\Omega_s$ of the underlining light source $p_*$ so that its strength could be reconstructed accurately. In the literature, $\Omega_s$ is assumed to be given in advance. Practically, we only get an approximation $\Omega_a$ of it, known from some a priori information. The accuracy of $\Omega_a$ affects largely the one in approximate solutions of $p_*$. Therefore, in this talk, a new time-dependent coupled model is proposed motivated by the solution uniqueness. Some theoretical and numerical results are reported for the verification of the new model and methods.

报告人简介：龚荣芳，南京航空航天大学数学学院，教授、硕士生导师。2009年博士毕业于浙江大学。随后进入南京航空航天大学数学系工作，期间于2014-2015年在美国Iowa大学、2016年在瑞典Orebro大学、2018年在澳大利亚国立大学访问。龚荣芳博士的研究方向主要包括光学成像、Cauchy问题等应用反问题的建模、正则化理论与方法，已在《Numerische Mathematik》、《Inverse Problems》、《Computational Methods in Applied Mechanics and Engineering》等发表SCI论文近30篇。主持完成国家自然科学基金青年项目、江苏省自然科学基金等7项。目前主持国家自然科学基金面上项目1项，参与国家面上项目1项。