{"id":511,"date":"2018-11-08T03:32:22","date_gmt":"2018-11-08T03:32:22","guid":{"rendered":"http:\/\/pages.charlotte.edu\/colloquium\/?p=511"},"modified":"2018-11-08T03:32:22","modified_gmt":"2018-11-08T03:32:22","slug":"monday-nov-12-1130am-1230-pm-fretwell-315","status":"publish","type":"post","link":"https:\/\/pages.charlotte.edu\/colloquium\/blog\/2018\/11\/08\/monday-nov-12-1130am-1230-pm-fretwell-315\/","title":{"rendered":"Monday, Nov 12, 11:30AM-12:30 PM, Fretwell 315"},"content":{"rendered":"<table>\n<tbody>\n<tr style=\"height: 24px\">\n<td style=\"height: 24px\">Dr.\u00a0<a href=\"http:\/\/sites.uml.edu\/min-hyung-cho\/\"><span style=\"color: #000000\">Min Hyung Cho<\/span><\/a><span style=\"color: #333333\">,\u00a0 University of Massachusetts at Lowell\u00a0<\/span><\/td>\n<\/tr>\n<tr style=\"height: 24px\">\n<td style=\"height: 24px\">Title: Fast Integral equation methods for wave scattering in layered media<\/td>\n<\/tr>\n<tr style=\"height: 144px\">\n<td style=\"height: 144px\">Abstract: Many modern electronic\/optical devices rely on waves such as solar cells, antennae, radar, and lasers. These devices are mostly built on a patterned layered structure. For optimizing and characterizing these devices, numerical simulations play a crucial role. In this talk, an integral equation method in 2- and 3-D layered media Helmholtz equation will be presented. In 2-D, the boundary integral equation with the periodizing scheme is used. This method uses near- and far-field decomposition to avoid using the quasi-periodic Green\u2019s function. By construction, the far-field contribution can be compressed using Schur complement with minimal computational cost. The new method solved the scattering from a 1000-layer with 300,000 unknown to 9-digit accuracy in 2.5 minutes on a workstation. In 3-D, a Lippmann-Schwinger type volume integral equation is used with layered media Green\u2019s function to include interface condition between layers and reduces the problem to only scatterers.<\/p>\n<div>In both 2- and 3-D layered media, a fast integral operator application is required because integral equation methods usually yield a dense matrix system. A heterogenous fast multipole method (H-FMM) is developed. This is a hierarchical method and uses recursively-generated tree-structure. The interactions from far fields are compressed with free-space multipole expansion. All the spatially variant information are collected into the multipole-to-local translation operators. As a result, many free-space tools can be adapted directly without any modification to obtain an optimal O(N) algorithm for low frequency.<\/div>\n<div><\/div>\n<div><\/div>\n<div>This is a joint work with Jingfang Huang (UNC), Alex Barnett (Dartmouth College), Duan Chen (UNC Charlotte), and Wei Cai (Southern Methodist University)<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Dr.\u00a0Min Hyung Cho,\u00a0 University of Massachusetts at Lowell\u00a0 Title: Fast Integral equation methods for wave scattering in layered media Abstract: Many modern electronic\/optical devices rely on waves such as solar cells, antennae, radar, and lasers. These devices are mostly built on a patterned layered structure. For optimizing and characterizing these devices, numerical simulations play a [&hellip;]<\/p>\n","protected":false},"author":333,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"class_list":["post-511","post","type-post","status-publish","format-standard","hentry","category-spring-2022"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p3kCtT-8f","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts\/511","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/users\/333"}],"replies":[{"embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/comments?post=511"}],"version-history":[{"count":1,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts\/511\/revisions"}],"predecessor-version":[{"id":512,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts\/511\/revisions\/512"}],"wp:attachment":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/media?parent=511"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/categories?post=511"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/tags?post=511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}