General Information
Keynote Speaker

Professor Weng Cho Chew, University of Illinois at Urbana–Champaign, USA

Topic: Overview of the Equivalence Principle Algorithm

Abstract: The equivalence principle algorithm (EPA) is a descendent of the nested equivalence principle algorithm (NEPAL).  It came about as a need to solve multi-scale problems which are commonly encountered in many practical engineering applications.  For instance, the simulation of a computer circuit board can entail regions where the fine details cannot be ignored. The finely detailed region is necessary to capture circuit physics which is indispensable in the entire working of the circuit board.  Another commonly encountered scenario is in antennas mounted on large platforms.  The feeds of antenna entail circuit physics, and hence, fine meshing is imperative in capturing the physics of the antenna feeds.  Yet another scenario is when multi-scale structures such as antennas are mounted on an ultra-large platform. The ultra-large platform is many wavelengths in size and is only amenable to high-frequency solutions which are often approximate. However, auto-mesh refinement, which is a way to capture the geometry of highly refined region, gives rise to ill-conditioned matrix systems, which are not amenable easily to iterative solvers.  EPA allows the domain decomposition, partitioning, and the separation of the circuit physics region away from the wave physics region. In the extreme case, it allows the separation of the circuit physics region from the ray-physics region. The large platforms can often be more expeditiously solved with fast iterative solvers. Even then, the scaling properties of fast iterative solvers cannot enable the efficient solutions of ultra-large platforms. In this case, approximate ray-physics based high frequency methods such as physical optics, geometric optics, and other high-frequency asymptotic methods may need to be employed.  An overview of various applications of EPA will be given.
The EPA is a domain decomposition method for disentangling circuit physics regions from the wave (ray) physics regions. By so doing, it allows for the expeditious solutions of large complex multi-scale structures.  It is especially useful for the modeling of circuit boards and antennas mounted on platforms where circuit physics and wave (ray) physics are both imperative in understanding the operating principles of a complex electromagnetic structure.

Bio: W.C. Chew received all his degrees from MIT.   His research interests is in wave physics, specializing in fast algorithms for multiple scattering imaging and computational electromagnetics in the last 30 years.  His recent research interest is in combining quantum theory with electromagnetics, and differential geometry with computational electromagnetics.  After MIT, he joined Schlumberger-Doll Research in 1981.  In 1985, he joined U Illinois Urbana-Champaign, was then the director of the Electromagnetics Lab from 1995-2007.  During 2000-2005, he was the Founder Professor, 2005-2009 the YT Lo Chair Professor, and since 2013 the Fisher Distinguished Professor.  During 2007-2011, he was the Dean of Engineering at The University of Hong Kong.   He has co-authored three books, many lecture notes, over 400 journal papers, and over 600 conference papers.  He is a fellow of various societies, and an ISI highly cited author.   In 2008, he received the IEEE AP-S CT Tai Distinguished Educator Award, in 2013, elected to the National Academy of Engineering, and in 2015 received the ACES Computational Electromagnetics Award.  He is selected to receive the 2017 IEEE Electromagnetics Award, and be the IEEE AP-S President Elect.