*********************************
There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
*********************************
Title: Error Estimation and Adaptive Refinement Technique in the Method of Moments
Committee:
Dr. Andrew Peterson, ECE, Chair , Advisor
Dr. Waymond Scott, ECE
Dr. Gregory Durgin, ECE
Dr. Emmanouil Tentzeris, ECE
Dr. Federico Bonetto, Math
Abstract: The objective of this dissertation is to develop a reliable and computationally inexpensive adaptive h-refinement technique for the three-dimensional method of moments to reduce numerical errors in electromagnetics efficiently. The adaptive refinement technique consists of an error estimator and a control algorithm. Error estimation plays an important role because it determines regions where error is large. Various error estimators are investigated and implemented. With the Pearson correlation coefficient, local error plots, and scatter plots comparing the estimated errors with actual errors, we evaluate reliability and efficiency of the error estimators. Based on the study of the initial error estimators, we invent new error estimators, which satisfy accuracy and efficiency simultaneously. The controller in the adaptive h-refinement technique is required to adjust mesh sizes and to maintain mesh quality over the regions that are identified for the refinement. The control algorithm distributes new nodes on the domains to be refined and employs the advancing front Delaunay algorithm to generate refined meshes. Since the quality of refined meshes can be aggravated during this procedure, we adopt Laplacian smoothing, which adjusts node positions by taking the average of their adjacent node positions. Numerical results of the error estimator assessment and the adaptive h-refinement technique will be presented and discussed.
