A major limitation of the boundary element method (BEM) for the solution of electrical potential problems is the long computational time required. However, a large portion of the calculations involved can be viewed as...
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A major limitation of the boundary element method (BEM) for the solution of electrical potential problems is the long computational time required. However, a large portion of the calculations involved can be viewed as being parallel in nature and can therefore be computed concurrently. This paper makes an effort to increase the efficiency of the BEM process using transputer-based multiprocessor computing techniques. The algorithms developed may equally well be applied to any multiprocessor system. The application selected to demonstrate the technique is the solution of an electrostatic problem governed by a two-dimensional Laplace equation. A parallel algorithm for problem setup and field extraction using BEM is designed and implemented on a transputer array. Special attention is directed to the utilization of the parallel processors to achieve maximum efficiency. The analysis in this work concentrates on the communication strategies for passing data between processors as well as a consideration of the workload attributed to each processor. The parallel algorithms were implemented using 3L Parallel Fortran;however, the choice of topology for the overall BEM implementation was limited by the fact that certain parts of the algorithm could only utilize a pipeline configuration of processors. Comprehensive results for the parallel BEM algorithm are given and they are encouraging, indicating that parallel processing has much to offer when applied to the boundary element method.
A major limitation of the transmission-line matrix (TLM) method used to solve Maxwell's equations is the long computation time required. The TLM scattering calculations involved can, however, be viewed as parallel...
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A major limitation of the transmission-line matrix (TLM) method used to solve Maxwell's equations is the long computation time required. The TLM scattering calculations involved can, however, be viewed as parallel in nature. This paper describes an effort to reduce computational time by using an SIMD, DAP multiprocessor computer employed to solve a two-dimensional TLM electromagnetic field formulation. A parallel algorithm based on the TLM scattering algorithm is designed and implemented using FORTRAN-PLUS Enhanced on an AMT DAP 510 machine. Here the connectivity of the DAP is exploited to simulate the intrinsic scattering behaviour on which the TLM algorithm relies. The results show that parallel processing on an SIMD machine such as the DAP is advantageous, especially for higher-order mesh sizes.
作者:
MENSH, DRKITE, RSDARBY, PHDennis Roy Mensh:is currently the task leader
Interoperability Project with the MITRE Corporation in McLean Va. He received his B.S. and M.S. degrees in applied physics from Loyola College in Baltimore Md. and the American University in Washington D. C. He also has completed his course work towards his Ph.D. degree in computer science specializing in the fields of systems analysis and computer simulation. He has been employed by the Naval Surface Warfare Center White Oak Laboratory Silver Spring Md. for 20 years in the areas of weapon system analysis and the development of weapon systems simulations. Since 1978 he has been involved in the development of tools and methodologies that can be applied to the solution of shipboard combat system/battle force system architecture and engineering problems. Mr. Mensh is a member of ASNE MORS IEEE U.S. Naval Institute MAA and the Sigma Xi Research Society. Robert S. Kite:is a systems engineer with the Naval Warfare Systems Engineering Department of the MITRE Corporation in McLean
Va. Mr. Kite received his B.S. degree in electronic engineering from The Johns Hopkins University in Baltimore Md. Mr. Kite retired from the Federal Communications Commission in 1979 and served a project manager of the J-12 Frequency Management Support Project for the Illinois Institute of Technology Research Institute in Annapolis Md. before joining MITRE. Mr. Kite is presently a member of ASNE the Military Operations Research Society and an associate member of Sigma Xi. Paul H. Darby:has worked in the field of interoperability both in the development of interoperability concepts and systems since joining the Department of the Navy in 1967. He was the Navy's program manager for the WestPacNorth
TACS/ TADS and IFFN systems. He is currently head of the Interoperability Branch Warfare Systems Engineering Office Space and Naval Warfare Systems Command. He holds a B.S. from the U.S. Naval Academy.
JCS Pub 1 defines interoperability as “The ability of systems, units or forces to provide services to and accept services from other systems, units or forces and to use the services so exchanged to enable them to ope...
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JCS Pub 1 defines interoperability as “The ability of systems, units or forces to provide services to and accept services from other systems, units or forces and to use the services so exchanged to enable them to operate effectively together.” With JCS Pub 1 as a foundation, interoperability of systems, units or forces can be factored into a set of components that can quantify interoperability. These components are: media, languages, standards, requirements, environment, procedures, and human factors. The concept described in this paper uses these components as an analysis tool to enable specific detailed analyses of the interoperability of BFC3 systems, units, or forces for the purpose of uncovering and resolving interoperability issues and problems in the U.S. Navy, Joint, and Allied arenas. Also, as a management tool, the components can help determine potential interoperability characteristics of future U.S. Navy BFC3 systems for compliance with battle force systems architectures. The approach selected for the quantification of interoperability was the development of a set of measures of performance (MOPs) and measures of effectiveness (MOEs). The MOPs/MOEs were integrated with a candidate set of components, which were used to partition the totality of interoperability into measurable entities. The methodology described employs basic truth table theory in conjunction with logic equations to evaluate the interoperability components in terms of MOPs that were aggregated to MOEs. It is believed that this concept, although elementary and based on fundamental principles, represents an operationally significant approach rather than a theoretical approach to the quantification of interoperability. The vehicle used as a means to measure the MOPs and MOEs was the Research Evaluation and systems Analysis (RESA) computer modeling and simulation capability at the Naval Ocean systems Center (NOSC), San Diego, Calif. Data for the measurements were collected during a Tactical I
This paper describes a modularized AI system being built to help improve electromagnetic compatibility (EMC) among shipboard topside equipment and their associated systems. CLEER is intended to act as an easy to use i...
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This paper describes a modularized AI system being built to help improve electromagnetic compatibility (EMC) among shipboard topside equipment and their associated systems. CLEER is intended to act as an easy to use integrator of existing expert knowledge and pre-existing data bases and large scale analytical models. Due to these interfaces; to the need for portability of the software; and to artificial intelligence related design requirements (such as the need for spatial reasoning, expert data base management, model base management, track-based reasoning, and analogical (similar ship) reasoning) it was realized that traditional expert system shells would be inappropriate, although relatively off-the-shelf AI technology could be incorporated. In the same vein, the rapid prototyping approach to expert system design and knowledge engineering was not pursued in favor of a rigorous systems engineering methodology. The critical design decisions affecting CLEER's development are summarized in this paper along with lessons learned to date all in terms of “how,” “why,” and “when” specific features are being developed.
This paper discusses the Interactive Graphics system used by the General Electric Company, Medium Steam Turbine department (Engineering & Manufacturing) for designing, drafting, and manufacturing applications. A b...
This paper discusses the Interactive Graphics system used by the General Electric Company, Medium Steam Turbine department (Engineering & Manufacturing) for designing, drafting, and manufacturing applications. A brief overview of the hardware malting up the system is described, followed by a more detailed description of the actual applications. Two-dimensional applications described include a Heat Balance Analysis, Flow Diagrams, and Electrical Schematics. A more fruitful area for increased productivity gains is described in the three-dimensional or mechanical applications including turbine design & layout and bucket design. coordination of the design with manufacturing for numerical control tape generation is described through CAM and Plate Frame Cutting applications. Finally, a short review of the engineering design work using Interactive Graphics is discussed. Productivity gains of 2.6 to 1 are being realized, and the overall savings to the Medium Steam department are outlined.
作者:
JOLLIFF, JVCALLAHAN, CMUSNCapt. James V. Jolliff
USNgraduated from the U. S. Naval Academy in 1954. Following graduation he served in the USS S. N. Moore (DD—747) and USS Cimarron (AO—22). He received his MS degrees in Naval Architecture from Webb Institute of Naval Architecture and in Financial Management from The George Washington University. He culminated his education at The Catholic University of America where he was awarded his Doctorate in Ocean Engineering in 1972. Capt. Jolliff has served in Naval Shipyards as Ship Superintendent Assistant Repair Officer and Assistant Planning & Estimating Superintendent and as such was primarily concerned with the repair and conversion of U. S. Navy skips. In addition he has served as Maintenance Officer Staff of Commander Mine Force U. S. Pacific Fleet as Co—Chairman of the Naval Engineering Division
Engineering Department U. S. Naval Academy and as CV Design Manager in the Advanced Concepts Division and as Head
Ship Survivability Office Naval Ship Engineering Center. An active member of ASNE since 1966 he has served as a member of the National Council and is currently the Chairman of the Journal Committee. He has had several papers presented at ASNE Day and published in the Journal and in 1976 was one of the recipients of the ASNE President's Award. At the present time he is assigned as the Commanding Officer Naval Coastal Systems Laboratory (NCSL) Panama City Fla. Mr. Casville M. Callahanis a native of Southwest Virginia where he attended Elementary and Secondary School prior to his three year's service in the U. S. Navy during World War II. He graduated from Lincoln Memorial University
Harrogate Tenn. in 1950 receiving his BS degree in Mathematics. In 1952 he received his MS degree in Mathematics from Auburn University Auburn Ala. and taught mathematics at Lincoln Memorial University and at Florida State University Tallahassee Fla. prior to joining the staff of the Mine Defense Laboratory in 1955. He has progressed through a variety of assignments as the Labo
Test and Evaluation have become paramount in today's department of Defense acquisition process. Therefore, the U. S. Navy requires both private and public facilities to accomplish the final goals of the “Fly befo...
Test and Evaluation have become paramount in today's department of Defense acquisition process. Therefore, the U. S. Navy requires both private and public facilities to accomplish the final goals of the “Fly before Buy” concept. Such a facility exists at the Naval Coastal systems Laboratory (NCSL); an integral part of the Chief of Naval Material's, Director of Navy Laboratories organization. This paper briefly addresses the Laboratory, its mission, and its history. This is followed by an in—depth facilities overview in order to create an understanding of the slow but steady evolution of NCSL's unique fixed facilities. These facilities, when coupled to the local natural environment, provide a unique in situ test and evaluation capability which is unequalled in the United States for assessing seagoing coastal systems. Of prime consideration is the Range Date Acquisition Center (RADAC) and Its ancillary subsystems for tracking, environmental monitoring, communications, and post run analysis. The paper is concluded with a discussion of both past and present use of the aforementioned facilities with an emphasis on user acceptance and future potential growth.
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