AbstractThis paper briefly describes a relatively new and unique professional society the Applied Computational Electromagnetics Society (ACES)--which provides a forum for issues relevant to numerical modeling in applied electromagnetics. The primary focus of ACES is on computational techniques, electromagnetics modeling software, and applications. Included in this paper is a description of the ACES annual symposium, publications, code user groups, benchmark problem solution workshops, short courses, software demonstrations, and other activities which serve the professional community. Introduction and BackgroundDuring the past several years, computer modeling and numerical methods have matured as problem-solving tools in real-world electromagnetics applications. Consequently, the need for an applications forum, of sufficient scope to include all modeling techniques and commonly used codes, became readily apparent. There was further consensus that both a regular meeting (with published proceedings) and an additional publication were appropriate. To these ends, ACES was organized, in 1986. Now formally chartered and incorporated as a non-profit organization, ACES is an international, inter-disciplinary, professional society, with a wide range of activities and services. The interdisciplinary scope of ACES is pivotal to maintaining a "cross-pollination" between the high-frequency and low-frequency applications. ACES activities and services have expanded to include canonical problem solution workshops (to "benchmark" the performance of codes and techniques) and code user groups, in addition to the newsletter, the journal, and the annual symposia. Furthermore, a Software Exchange Committee, and a Software Performance Standards Committee, provide a means to exchange information about electromagnetic computational codes and their performance in real-world applications. At the symposia, short courses and software demonstrations are offered. The ACES Journal is administered by an international editorial board, which presently represents nine nations. General Scope of ACES ActivitiesAmong other things, ACES activities relate to these areas:
Applications of interest include, but are not limited to antennas (and their electromagnetic environments, radar cross section, shielding, electromagnetic pulse (EMP), electromagnetic interference (EMI), electromagnetic compatibility (EMC), microwave components, fiber optics, electromagnetic wave propagation, non-destructive evaluation, eddy currents, and inverse scattering. Interests include frequency-domain and time-domain techniques, from integral equation formulations to diffraction theories and physical optics. Code User GroupsTo provide needed links between developers and users of electromagnetics modeling codes and techniques, ACES is forming several code user groups. The following benefits to code developers and to code users are envisioned:
Some of these benefits to users are contingent upon the cooperation of the respective code developers, whereas other benefits can be provided independently. However, in the interest of serving developers and users alike, ACES is seeking full cooperation from the developers, who are also being encouraged to maintain existing user-support arrangements for non-members of ACES. Benchmark Problem Solution WorkshopsAn essential code and model validation task is the testing of the codes and computational models against benchmark problems, which themselves require careful selection. This task is already underway, with the publication of "The ACES Collection of Canonical Problems--Set 1" in the Spring of 1990. With this set of problems, ACES offers the computational electromagnetics community a set of tools which can be used to help validate models and the codes which execute those models. With frequencies ranging from 900 Hz to 10 GHz, the problems in Set 1 include not only perfectly conducting bodies, but also penetrable bodies. Transient as well as sinusoidal steady-state waveforms are represented in Set 1, and the applications include radar cross section, non-destructive evaluation, and inverse scattering. ACES will be publishing future collections of benchmark problems, and will be convening international workshops at which problem solutions will be presented. Whenever possible, ACES will sponsor these workshops jointly with other groups of computational electromagneticists. To that end, ACES is collaborating with the TEAM (Testing Electromagnetic Analysis Methods) Workshop, to sponsor joint ACES/TEAM international workshops for solving canonical problems in computational electromagnetics. The first such joint workshop was held in October, 199O, in Toronto. At that meeting, solutions to problems in both the TEAM collection and the ACES collection were presented, so that we could draw upon the expertise within both groups. A parallel effort of the Software Performance Standards Committee is the development of code performance standards. Also under development are procedures and protocols for the validation and performance analysis of codes and computational models. Performance assessments will be based on user-community feedback, and these assessments will be updated periodically as codes are modified, models are refined, and more test cases are investigated. This committee is collaborating with the AP-S EM Modeling Software Committee in the sharing of information, and in the participation of ACES members in the AP-S activity. The ACES NewsletterSeveral types of articles or columns appear in the ACES Newsletter, including the following:
The ACES JournalThe ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state of the art, and to the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to "re-invent the wheel" to solve a previously solved computational problem in electrical engineering, physics, or related fields of study. The ACES Journal welcomes original, previously unpublished papers, relating to applied computational electromagnetics. All papers are refereed. A unique feature of the ACES Journal is the publication of unsuccessful efforts in applied computational electromagnetics. Publication of such material provides a means to discuss problem areas in electromagnetic modeling. of course, material representing an unsuccessful application or negative result in computational electromagnetics is considered for publication only if a reasonable expectation of success (and a reasonable effort) are reflected. Other ACES Activities and ServicesA database is evolving out of the various ACES activities. It consists of computational data to be used for code validation, performance analysis and optimization, as well as information about particular codes and techniques. Each data set will be documented to include the code and machine used, input variables (including numerical grids, where possible), number of unknowns, basis and testing functions (where appropriate), a priori assumptions and simplifying approximations, computational method, and solution technique. Also included will be the code memory requirements typical run times, and maximum number of unknowns. A primary objective of this data base is to establish a "baseline" for the capabilities and limitations of various codes for different applications, so as to provide the best possible user guidelines. In addition, the data base provides an informal peer-review mechanism for codes and computational techniques to facilitate a rapid transfer of useful knowledge into the mainstream of the numerical electromagnetics community. A small software library is maintained by the Software Committee. There are also tentative plans for additional activity in artificial intelligence/expert systems and in computational electromagnetics education. Membership and SubscriptionsThe annual membership fee includes subscriptions to the Journal and the Newsletter. Further information regarding individual or institutional ACES memberships, the ACES publications and other ACES activities can be obtained from the ACES Secretary: Dr. Richard W. Adler |
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