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Great Lakes Symposium on VLSI

作者： S. Srinivas A. Basu A. Paulraj L.M. Patnaik Department of Electrical and Computer Engineering Concordia University Montreal QUE Canada Centre for Development of Advanced Computing Bangalore India Microprocessor Applications Laboratory Supercomputing Education and Research Center Department of Computer Science and Automation Indian Institute of Science Bangalore India

The authors present a parallel algorithm for logic simulation of VLSI circuits. It is implemented on a network of transputers connected in a ring topology. The approach is based on partitioning a functionality matrix representation of the circuit among the transputers and adopting a data flow technique for the solution. A significant aspect of the algorithm is that it overlaps computation with communication, thereby reducing the communication overhead. It also attempts even distribution of load in order to reduce processor idle time. The algorithm possesses the advantages of ease of implementation and ease of extension to incorporate additional parameters for simulation. Performance results of the algorithm are given.< >

关键词： Parallel algorithms Circuit simulation Computational modeling Concurrent computing Application software Logic circuits Very large scale integration Algorithm design and analysis Logic design Design automation

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FULL-WAVE SOLUTION OF DIELECTRIC LOADED WAVE-GUIDES AND SHIELDED MICROSTRIPS UTILIZING FINITE-DIFFERENCE AND THE CONJUGATE-GRADIENT METHOD

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INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE computer-AIDED engineering 1991年第4期1卷 346-357页

作者： NARAYANAN, V MANELA, M LADE, RK SARKAR, TK Department of Electrical and Computer Engineering Syracuse University Syracuse New York 13244-1240 Viswanathan Narayanan was born in Bangalore India on December 14 1965. He received the BE degree in Electronics and Communications from B.M.S. College of Engineering Bangalore in 1988. He joined the Department of Electrical Engineering at Syracuse University for his graduate studies in 1989 where he is currently a research assistant. His research interests are in microwave measurements numerical electromagnetics and signal processing. Biographies and photos are not available for M. Manela and R. K. Lade. Tapan K. Sarkar (Sf69-M'76-SM'X1) was born in Calcutta. India on August 2 1948. He received the BTech degree from the Indian Institute of Technology Kharagpur India in 1969 the MScE degree from the University of New Brunswick Fredericton Canada in 1971. and the MS and PhD degrees from Syracuse University. Syracuse NY in 1975. From 1975-1976 he was with the TACO Division of the General Instruments Corporation. He was with the Rochester Institute of Technology (Rochester NY) from 1976-1985. He was a Research Fellow at the Gordon Mckay Laboratory Harvard University Cambridge MA from 1977 to 1978. He is now a Professor in the Department of Electrical and Computer Engineering Syracuse University. His current research interests deal with numerical solutions of operator equations arising in electromagnetics and signal processing with application to system design. He obtained one of the “ best solution” awards in May 1977 at the Rome Air Development Center (RADC) Spectral Estimation Workshop. He has authored or coauthored more than 154 journal articles and conference papers and has written chapters in eight books. Dr. Sarkar is a registered professional engineer in the state of New York. He received the Best Paper Award of the IEEE Transactions on Electromagnetic Compatibility in 1979. He was an Associate Editor for feature articles of the lEEE Antennas arid Propagation Sociefy Newsletter and was

Dynamic analysis of waveguide structures containing dielectric and metal strips is presented. The analysis utilizes a finite difference frequency domain procedure to reduce the problem to a symmetric matrix eigenvalue problem. Since the matrix is also sparse, the eigenvalue problem can be solved quickly and efficiently using the conjugate gradient method resulting in considerable savings in computer storage and time. Comparison is made with the analytical solution for the loaded dielectric waveguide case. For the microstrip case, we get both waveguide modes and quasi-TEM modes. The quasi-TEM modes in the limit of zero frequency are checked with the static analysis which also uses finite difference. Some of the quasi-TEM modes are spurious. This article describes their origin and discusses how to eliminate them. Numerical results are presented to illustrate the principles.

关键词： Waveguides

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HYDRODYNAMIC EFFICIENCY IMPROVEMENTS FOR UNITED-STATES NAVY SHIPS

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NAVAL ENGINEERS JOURNAL 1991年第3期103卷 74-90页

作者： MCCALLUM, D ENGLE, AH PLATZER, GP KARAFIATH, G Donald McCallumis a supervisory naval architect in the Auxiliary Amphibious and Mine Warfare Ship Hydrodynamics Branch of the Naval Sea Systems Command. He has worked in ship design in his native Scotland before coming to the United States via Canada. Mr. McCallum has a M.Sc. degree from the University of Michigan and a B.Sc. from Strathclyde University (Glasgow). He is a member of SNAME ASNE and ASE. Allen H. Engleis a naval architect with the Hull Form and Hydrodynamic Performance Division of the Naval Sea Systems Command (NavSea). He received his B.S. degree in engineering science from the State University of New York at Buffalo in 1977 and his M.S. degree in ocean engineering from the University of Hawaii in 1979. Since 1980 he has worked for NavSea where he has been assigned to the Philadelphia Naval Shipyard SupShip Seattle and the U.S. Naval Academy Hydromechanics Laboratory. Selected as NavSea's Engineer of the Year for 1989 Mr. Engle is currently the program director for the Navy's Hydrodynamic Loads Technology Development Program. Prior to his current assignment Mr. Engle was technical director of the Navy's Ship Efficiency Improvement Program and task leader for hydrodynamic design for the LHD-5 AO-177 (Jumbo) AE-36 LSD-41 and FFX ship designs. Mr. Engle is a member of both ASNE and SNAME. Gregory Platzeris currently employed with Arneson Marine Inc. As manager of applications engineering Mr. Platzer is responsible for the development of propulsion specifications for articulated surface drive units matched to high-speed partially submerged propellers. Prior to November 1990 Mr. Platzer was the head of the Surface Ship Propeller Branch at the Naval Sea Systems Command. He had worked for the Navy in the field of propulsor analysis since 1977 initially at the David Taylor Research Center. Mr. Platzer graduated in 1977 from the University of Michigan with a B.S. degree in naval architecture. Gabor Karafiathis a member of the Ship Hydromechanics Department at the David Taylor Research Center.

This paper reports on an investigation of the applicability of recent hull efficiency improvement concepts to U.S. Navy ships. Among the concepts investigated were stern flaps, Grim Wheels, alternate aftbody configurations, bulbous bows, and flow modifying ducts. Extensive model testing was conducted at the David Taylor Research center (DTRC) for each concept, and care was taken to check out critical propeller cavitation and noise aspects associated with the investigation of alternate stern configurations and Grim Wheel concepts. A guiding principle in this program was to utilize the expertise available both here and abroad so that each design concept would have the greatest chance of success. As a result of these investigations, significant gains in fuel economy were obtained. Specifically, full scale trials of FFG-25 (USS Copeland), equipped with and without a stern flap, demonstrated that fuel savings of 5-9% are achieved at speeds above 12 knots. In addition, fuel savings of 9.4% for T-AGS 39 equipped with a Grim Wheel and 5.6% for the combination of a large bulbous bow and a large diameter/low RPM propeller on AE-36 have been predicted. The paper concludes with a direction for future applications to U.S. Navy, and other ships.

关键词： Warships

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ADAPTIVE MESH GENERATION FOR VISCOUS FLOWS USING DELAUNAY TRIANGULATION

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JOURNAL OF COMPUTATIONAL PHYSICS 1990年第2期90卷 271-291页

作者： MAVRIPLIS, DJ Institute for Computer Applications in Science and Engineering NASA Langley Research Center Hampton Virginia 23665 USA

A method for generating an unstructured triangular mesh in two dimensions, suitable for computing high Reynolds number flows over arbitrary configurations is presented. The method is based on a Delaunay triangulation, which is perfored in a locally stretched space, in order to obtain very high-aspect-ratio tiangles in the boundary layer and wake regions. It is shown how the method can be coupled with an unstructured Navier-Stokes solver to produce a solution-adaptive mesh generation procedure for viscous flows.

关键词： Viscous flow

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A SIMPLE NONLINEAR MODEL FOR THE RETURN TO ISOTROPY IN TURBULENCE

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PHYSICS OF FLUIDS A-FLUID DYNAMICS 1990年第1期2卷 84-93页

作者： SARKAR, S SPEZIALE, CG Institute for Computer Applications in Science and Engineering NASA Langley Research Center Hampton Virginia 23665

A quadratic nonlinear generalization of the linear Rotta model for the slow pressure‐strain correlation of turbulence is developed for high Reynolds number flows. The model is shown to satisfy realizability and to give rise to no stable nonzero equilibrium solutions for the anisotropy tensor in the case of vanishing mean velocity gradients. In order for any model to predict a return to isotropy for all relaxational flows, it is necessary to ensure that there is no nonzero stable fixed point that attracts realizable initial conditions. Both the phase space dynamics and the temporal behavior of the model are examined and compared against experimental data for the return to isotropy problem. It is demonstrated that the quadratic model successfully captures the experimental trends which clearly exhibit nonlinear behavior. Comparisons are also made with the predictions of the linear Rotta model, the quasilinear Lumley model, and the nonlinear model of Shih, Mansour, and Moin. The simple quadratic model proposed in this study does better than the Rotta model as anticipated, and also compares quite favorably with the other more complicated nonlinear models.

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The analysis and simulation of compressible turbulence

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Theoretical and Computational Fluid Dynamics 1990年第2期2卷 73-95页

作者： Erlebacher, Gordon Hussaini, M.Y. Kreiss, H.O. Sarkar, S. Institute for Computer Applications in Science and Engineering NASA Langley Research Center Hampton 23665 VA United States University of California at Los Angeles Los Angeles 90024 CA United States Institute for Computer Applications in Science and Engineering NASA Langley Research Center Hampton 23665 VA United States

This paper considers compressible turbulent flows at low turbulent Mach numbers. Contrary to the general belief that such flows are almost incompressible (i.e., the divergence of the velocity field remains small for all times), it is shown that even if the divergence of the initial velocity field is negligibly small, it can grow rapidly on a nondimensional time scale which is the order of the fluctuating Mach number. An asymptotic theory which enables a description of the flow in terms of its divergence-free and vorticity-free components has been developed to solve the initial-value problem. As a result, the various types of low Mach number turbulent regimes have been classified with respect to the initial conditions. Formulae are derived that accurately predict the level of compressibility after the initial transients have disappeared. These results are verified by extensive direct numerical simulations of isotropic turbulence. © 1990 Springer-Verlag.

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On the analysis of three symmetrically coupled microstrip lines on anisotropic substrates

On the analysis of three symmetrically coupled microstrip li...

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Antennas and Propagation Society International Symposium

作者： L. Yu B. Rawat Electrical Engineering/Computer Science Department University of Nevada슠Reno Reno NV USA Microwave Applications Research Center Electrical Engineering/Computer Science Department University of Nevada슠Reno Reno NV USA

A system of three symmetrically coupled microstrip lines on an anisotropic substrate is analyzed. The method used is a straightforward approach involving matrix inversion. Numerical results are computed and plotted using a Green's function method for three mode impedances of a three-line microstrip coupler on an anisotropic substrate ( in /sub zeta /=3.4, in /sub eta /=5.12, theta =30 degrees ).< >

关键词： Microstrip Anisotropic magnetoresistance Impedance Dielectric substrates Boundary conditions Conductors Application software Capacitance Transmission line matrix methods Green's function methods

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AN ANNEALING-BASED CIRCUIT PARTITIONER FOR HYPERCUBE ARCHITECTURE: DESIGN AND PERFORMANCE EVALUATION

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International Journal of High Speed Computing 1990年第1期2卷 69-84页

作者： SRILATA RAMAN L.M. PATNAIK Dept. of Electrical and Computer Engineering and Coordinated Science Laboratory University of Illinois at Urbana-Champaign IL 61801 U.S.A Microprocessor Applications Laboratory Dept. of Computer Science and Automation and Supercomputer Education and Research Center Indian Institute of Science Bangalore 560 012 India

This paper discusses the parallel implementation of a hypercube-based circuit partitioning scheme. The circuit partitioner is based on a simulated annealing algorithm and is designed to provide near optimal circuit partitions for simulating the circuits on a hypercube architecture. The circuit partitioning scheme optimizes multiple criteria such as tight coupling of nodes within a subcircuit, load balancing among processors and communication overheads. Design of a partitioner that obtains near optimal solutions satisfying such multiple criteria is difficult using any simple heuristic techniques other than simulated annealing.

关键词： Circuit simulation circuit partitioning simulated annealing hypercube architecture

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Improved fuzzy process control of spacecraft autonomous rendezvous using a genetic algorithm

Improved fuzzy process control of spacecraft autonomous rend...

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Intelligent Control and Adaptive Systems 1989

作者： Karr, C.L. Freeman, L.M. Meredith, D.L. U.S. Bureau of Mines Tuscaloosa Research Center TuscaloosaAL35487-9777 United States University of Alabama Department of Aerospace Engineering TuscaloosaAL35487-0280 United States University of Alabama Department of Computer Science TuscaloosaAL35487-0290 United States

The U.S. Bureau of Mines is currently investigating ways to combine the control capabilities of fuzzy logic with the learning capabilities of genetic algorithms. Fuzzy logic allows for the uncertainty inherent in most control problems to be incorporated into conventional expert systems. Although fuzzy logic based expert systems have been used successfully for controlling a number of physical systems, the selection of acceptable fuzzy membership functions has generally been a subjective decision. In this paper, high-performance fuzzy membership functions for a fuzzy logic controller that manipulates a mathematical model simulating the autonomous rendezvous of a spacecraft are learned using a genetic algorithm, a search technique based on the mechanics of natural genetics. The membership functions learned by the genetic algorithm provide for a more efficient fuzzy logic controller than membership functions selected by the authors for the rendezvous problem. Thus, genetic algorithms are potentially an effective and structured approach for learning fuzzy membership functions. © 1990 SPIE. All rights reserved.

关键词： Genetic algorithms

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computer-AIDED-DESIGN METHODS FOR PROPELLER FILLET GAUGES

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NAVAL ENGINEERS JOURNAL 1990年第3期102卷 202-208页

作者： ALLEN, DW VINOSKI, WS OVERTON, BA David W. Allen:is a senior computer scientist at the Machinery Technology Division Westinghouse Electric Corporation Large Pa. He received the B.A. degree in mathematics from Grinnell College and the M.S. degree in computer science from the University of Pittsburgh. His career with Westinghouse has been divided between assignments in engineering and computer applications. Mr. Allen has published eight technical papers. He received the George Westinghouse Signature A ward of Excellence for his work on the development of the GAGES computer program for designing propeller gages. He is a member of the Association for Computing Machinery (ACM) and the Institute of Electrical and Electronics Engineers (IEEE). Walter S. Vinoski:is a project engineer at the Machinery Technology Division Westinghouse Electric Corporation Large Pa. and was instrumental in the development of the GAGES computer program. He was awarded the George Westinghouse Signature Award of Excellence for his work on the GAGES program. Mr. Vinoski has six years of marine propulsion system experience specifically with propellers. He earned a B.S. degree in electronics engineering and minored in mathematics at the Ohio Institute of Technology. He is a member of the American Society of Naval Engineers. Bernard A. Overton:graduated from North Carolina Agricultural and Technical State University Greensboro N.C. in 1958 with a B.S. degree in mechanical engineering. Within two years of joining the U.S. Army Mr. Overton was honorably discharged as a first lieutenant. Mr. Overton worked seven years at Philadelphia Naval Shipyard in the following areas: shafting shafting alignment bearing reactions noise and vibration surveys propellers and propeller blade gage designs. In 1967 Mr. Overton transferred to the Navy Engineering Center. He has worked on main propulsion devices such as water jets propellers (both submarine and surface ship) and propeller blade gages. Mr. Overton was responsible for the establishment of the Naval Inspectors Propeller Certif

One of the most complicated forms encountered in engineering design is that of the marine propeller. The complexities arise from the complicated hydrodynamic surfaces of the propeller blades and the complicated manner in which the blades are oriented with and attached to the hub. Where propeller blades are attached to the hub, the blade shape is blended into the shape of the hub. The geometry of this region is particularly complicated. The shape of the blend is called a fillet, and the blending region is called the fillet region. Sheet metal gages conforming to various blade surface contours are used in the manufacture and inspection of propellers. Five different types of gages define the shape of the propeller in different regions. Fillet gages are such gages that define the shape of propeller blades in the fillet region. This paper describes a new computer-aided method for designing fillet gages. Previous methods of fillet gage design required the designer to follow a complicated layout procedure of determining where a particular unfilleted blade contour intersected the hub. The design of the fillet was then done in another layout procedure. Newly developed numerical procedures incorporated in a computer program have reduced the time required to design a complete set of gages (including fillet gages) from up to several weeks to hours.

关键词： Propellers

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