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Stability of GaAs/Si Superlattices During MBE Growth and Post-Growth Annealing

MRS Online Proceedings Library 1993年第1期326卷 133-138页

作者： Wade, J.K. Moran, P.D. Gillespie, H.J. Crook, G.E. Matyi, R.J. Materials Science Program University of Wisconsin Madison USA Dept. of Electrical and Computer Engineering University of Wisconsin Madison USA Dept. of Materials Science and Engineering University of Wisconsin Madison USA

The stability of GaAs/Si superlattices grown on GaAs substrates using molecular beam epitaxy is described. Typical superlattice structures consisted of ten periods of thin (less than 6.5Å thick) layers of pseudomorphic silicon alternating with thick GaAs layers. We have examined the As2/Ga flux conditions required for the growth of high quality superlattices and have found that the structural perfection is extremely sensitive to the V/III flux ratio. The best superlattices were grown under condition that were just barely enough arsenic to produce a stable (2×4) surface reconstruction in the GaAs layers; increases in the arsenic overpressure resulted in a progressive trend towards 3-D growth of the GaAs on the pseudomorphic Si. In addition, we have examined the stability of GaAs/Si superlattices towards post-growth annealing. Double crystal x-ray diffraction scans showed little change in superlattice structure following rapid thermal anneals at 800°C; at 900°C, however, all but the first order satellite reflections disappeared. We attribute this behavior to the relaxation of pseudomorphic strin and the generation of misfit dislocations at the higher anneal temperature.

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Theory of The Active Nonlinear Coupler Laser

Theory of The Active Nonlinear Coupler Laser

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Nonlinear Guided-Wave Phenomena, NLGW 1993

作者： Walton, Donnell T. Winful, Herbert G. Applied Physics Program University of Michigan 1301 Beal Ave. Rm 1214 Ann ArborMI48109 United States Department of Electrical and Computer Engineering University of Michigan 1301 Beal Ave. Ann ArborMI48109 United States

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INTERLABORATORY COMPARISON OF MODE TRANSITION MATRICES

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APPLIED OPTICS 1993年第30期32卷 5997-6005页

作者： YANG, S YADLOWSKY, MJ HJELME, DR MICKELSON, AR When this research was performed the authors were with the Department of Electrical Computer Engineering University of Colorado Campus Box 425 Boulder Colorado 80309-0425. M. J. Yadlowsky is now with the Bioengineering Instrumentation Program National Institutes of Health Bethesda Maryland 20892. D. R. Hjelme is now with SINTEF-DELAB N-7034 Trondheim Norway.

An interlaboratory measurement round-robin was conducted by the university of Colorado and three industrial members of the Electronic Industries Association. A computational definition of mode transition matrices (MTM's) is presented, and its relationship to the basic theory of power propagation in multimode fibers is detailed. Measured data from the round-robin were used to calculate MTM's for the test components, which included four connectors, two sections of fiber cable, two power splitters, and two short fiber segments. The diagonal elements of the (2 x 2) MTM's determined from the near-field data were found to have a laboratory-to-laboratory standard deviation of approximately 10% of the average value. The off-diagonal elements were found to have a standard deviation approaching their mean value. The inherent launch dependence of MTM's is investigated as a source of the observed variation. Other sources of uncertainty such as errors in determining the core radius are also considered. Finally the implications of these results for the problem of characterizing components' intensive multimode fiber systems are discussed.

关键词： MULTIMODE FIBERS FIBER MEASUREMENTS FIBER COMPONENTS

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Energy based detection of seizures

Energy based detection of seizures

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： H.P. Zaveri W.J. Williams J.C. Sackellares Department of Electrical Engineering and Computer Science Bioengineering Program University of Michigan Ann Arbor MI USA Department of Neurology Epilepsy Program University of Michigan Ann Arbor MI USA

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PERFORMANCE TESTING OF SHIPBOARD ELECTRONIC SYSTEMS

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NAVAL ENGINEERS JOURNAL 1993年第3期105卷 118-124页

作者： HARDER, G MARTIN, RA PE George Harder:is an electronics engineer for Naval Undersea Warfare Center Detachment Norfolk's Electromagnetic Engineering Branch located at the Norfolk Shipboard Electronic Systems Evaluation Facility (SESEF) site. He is responsible for fleet electromagnetic readiness (FEMR) inspections on board Navy ships and provides computer programming support to SESEF. Mr. Harder has a bachelor of science degree in electrical engineering from the University of Florida and has qualified for his professional engineering license in the state of Virginia. Robert A. Martin:is a supervisor electronics engineer employed by the Naval Undersea Warfare Center Detachment Norfolk. He functions as the branch head for the Electromagnetic Engineering Office which is responsible for the operation of the Norfolk Shipboard Electronic Systems Evaluation Facility (SESEF) and the Fleet Electromagnetic Readiness (FEMR) Program. Mr. Martin received a bachelor of science degree in electrical engineering from the University of Akron.

Performance evaluation of shipboard electronic systems entails debugging the systems in a laboratory environment, placing them in service and relving on svstem operators to provide feedback. General testing can be performed at selected sites by system designers, but each site where equipment is to be installed can offer unique problems. It is impossible to predict all the scenarios. Unique problems are more the rule than the exception when equipment is destined for Navy ships. Ship deployments make for difficult logistics when sending test teams to evaluate system failures. So, out of necessity, if newly installed equipment receives the proper inputs and generates the proper outputs, it is accepted and becomes the sailor's responsibilitv to maintain. In cases where documentation is ambiguous or incomplete, it is left to the sailor's ingenuity to continue testing and training on equipment. This is generallv obtained through computer simulations and back-to-back testing which can provide results for ideal conditions, but does not take the dynamics of interference into account. Remote site testing is the only way to get a true representation of equipment performance and training problems. Electronic system operators on board Navy vessels are fortunate, thev have help. There exists an organization available near major naval ports worldwide whose existence is to test electronic systems performance. The testing utilizes electronic systems as they would normally be configured for operations. This organization is the Shipboard Electronic Svstem Evaluation Facility (SESEF).

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VIRTUAL PROTOTYPING USING KNOWLEDGE - BASED MODELING AND SIMULATION TECHNIQUES

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NAVAL ENGINEERS JOURNAL 1993年第3期105卷 201-212页

作者： SHEA, JG The Author:holds bachelor and master of engineering degrees in mechanical engineering a M.Eng. in engineering management and is currently fulfilling requirements for the M.S. and Ph.D. degrees in computer science at the University of Louisville. He is employed as program manager Phalanx Advanced Engineering Development at the Naval Ordnance Station Crane Div. NavSurfWarCen Louisville Ky. During his tenure with Phalanx Mr. Shea has contributed to system reliability improvement system performance upgrading and the development of the Phalanx HOL (RISC) Computer. Mr. Shea is a member of ASNE the Institute of Electrical and Electronics Engineers American Institute of Aeronautics and Astronautics Society for Computer Simulation International Test & Evaluation Association and the Military Operations Research Society.

Knowledge-based modeling and simulation bridges the gap between ''conventional'' artificial intelligence implementations (such as expert systems) and more traditional computer-aided design techniques. We are currently developing software, whose primary function is to capture a user-input design specification and produce a ''virtual'' rapid prototvpe in the form of executable rule-based code. This code can then be exercised either as an interactive part of a hardware-in-the-loop testbed simulator or as a component of an object-oriented ''behavioral'' simulation environment. While the Phalanx Testbed is the immediate beneficiary of this work, the techniques described have a wide range of application in the modeling of conceptual design and performance characteristics. This paper describes the system architecture and software tools that we are applying to generate virtual rapid prototypes for use in the Phalanx Testbed. Particular attention is paid to defining the intelligent knowledge-capture mechanisms and model generation methodologies that we are using to translate design knowledge and performance requirements into rule-based simulations. The object-oriented programming approach to the merging of ''new'' data with previouslv-captured and stored data is discussed, and the issues of verifying and validating prototypes generated using such partiallv ''reengineered'' models are examined. An application currently in use as an investigative prototype for testbed development, a simple position controller servomechanism used to control the azimuth angle of a target-tracking sensor, is used to illustrate the process.

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Educational use of a microwave electromagnetic analysis of 3-D planar structures

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computer Applications in engineering Education 1993年第3期1卷 243-243页

作者： Rautio, J.C. Sonnet Software Inc. Suite 203 135 Old Cove Road Liverpool NY 13090 Dr. James C. Rautio:founded Sonnet Software a developer of 3-D planar electromagnetic microwave software in 1983 with support from the David Sarnoff Research Center Hewlett Packard General Electric and Syracuse University. He has served as a visiting member of the faculty at Syracuse University and as an adjunct faculty member at Cornell University teaching microwave and computer courses as well as pursuing research in electromagnetics. Dr. Rautio previously worked in General Electric's Space Division and Electronics Laboratory. He designed microwave circuits including filters for a Landsat receiver and various GaAs microwave integrated circuits. He also developed microwave and millimeter wave automated measurement equipment and wrote a large microwave circuit analysis program. Dr. Rautio holds a BS in Electrical Engineering from Cornell University an MS in Systems Engineering from the University of Pennsylvania and a PhD in Electrical Engineering from Syracuse University

The use of an electromagnetic analysis of 3-D planar structures is described with respect to the educational requirements of students from the college freshman level through the graduate level. The analysis is intended primarily for microwave use; however, there is also significant potential interest from the student of high speed digital design. The analysis is used for passive planar circuits with any number of layers. The third dimension is represented by vias. A mature graphical user interface is provided allowing rapid capture of structure geometry, color visualization, and animation of the resulting current distributions. The software is also explicitly designed to work in conjunction with popular circuit theory based microwave software and with SPICE.

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COMBAT SYSTEM engineering - A RETURN TO FUNDAMENTALS

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NAVAL ENGINEERS JOURNAL 1993年第3期105卷 61-69页

作者： MITTURA, A KARP, MS PE Andrew Mittura:is currently a senior program engineer with SYSCON Corp. He began his career in the Combat System Installation and Integration Office of NavSea in 1978. He has worked as a system engineer on the Seafire program at NSWCDD on the NATO Anti-air Warfare Program while at FMC Corporation and for the past four years on the Aegis Combat System with SYSCON. Current efforts include performance assessment studies of the Aegis combat system and combat system architecture and connectivity analysis. Mr. Mittura received a B.S. in electrical engineering from Penn State University in 1978 and an M.S. in engineering management from Catholic University of America in 1982. He is a licensed professional engineer with the State of Virginia. Mitchel S. Karp:cofounded K&K Software Engineering Inc. in February 1970. He is currently secretary/treasurer and senior system engineer. His involvement in combat systems began with NTDS in 1963. He has been involved in the Aegis Program since 1968 and has worked in all aspects of combat system development including computer programming tactical analysis software development and management. He has given several seminars on real-time software development and documentation. He currently is working under contracts to NSWCDD in the areas of combat system architecture and connectivity configuration management and documentation. Mr. Karp received a B.S. in engineering physics from Lehigh University in 1958.

The Navy's focus has shifted from global war scenarios to preparedness for the prospect of involvement in regional, littoral contingencies and conflicts. Operationally, shipboard personnel will need the ability to shift focus from the combat system multimission roles to that of only a single mission. From a development perspective, combat systems must accommodate a continual infusion of technology in a budget constrained environment. Combat system architecture is the single most important feature affecting combat system flexibility, from both an operational and developmental aspect. There is a fundamental partitioning of combat svstem functions into detect, command, and engage in a horizontal integration approach that enhances this needed flexibilitv. This fundamental partitioning is currently applied to individual weapon systems, but not to combat svstems as a whole. Instead, self-contained weapon systems are often developed and then vertically integrated to form a combat svstem, causing reduced flexibility. The battle organization is the principal driving requirement for combat system architecture. This paper shows that that the battle organization is best supported by a horizontally integrated combat system of detect, command, and engage. It concludes that a horizontally integrated combat svstem architecture of detect, command, and engage should be a candidate for future combat systems.

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Interactive tools for signal processing education. The signal processing instructional facility (SPIF lab) at Washington State university

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computer Applications in engineering Education 1993年第6期1卷 517-517页

作者： Bamberger, R.H. Signal Processing Instructional Facility School of Electrical Engineering and Computer Science Washington State University Pullman WA 99164-2752 Dr. Roberto H. Bamberger:was born on January 30 1965 in Buenos Aires Argentina. He received his B.E.E and PhD from the Georgia Institute of Technology in 1986 and 1990 respectively. Currently Dr. Bamberger is an assistant professor in the School of Electrical Engineering and Computer Science at Washington State University. Dr. Bamberger's research program is focused on the design implementation and application of multidimensional multirate filter banks subband image and video compression analysis of nonstationary data and application of digital signal processing techniques in the design of analog and mixed-mode integrated circuits. Dr. Bamberger is the founder and director of the Signal Processing Instructional Facility (SPIF Lab) at Washington State University. The SPIF Lab features interactive multimedia-based tools for teaching concepts related to linear systems theory. Dr. Bamberger is active in developing multimedia-based instructional laboratories for a variety of other topics as well. In addition to his teaching and research programs Dr. Bamberger is an associate editor for theIEEE Transactions on Signal Processingand a member of the editorial board forComputer Applications in Engineering Education. Dr. Bamberger is also advisor to the WSU Student Branch of the IEEE and assistant director of the WSU Cougar Marching Band. Dr. Bamberger is a member of Phi Eta Sigma Eta Kappa Nu Tau Beta Pi and Kappa Kappa Psi.

The Signal Processing Instructional Facility (SPIF Lab) is an experiment in using in interactive multimedia for teaching concepts related to linear systems theory and signal processing. The goals of the SPIF lab are to augment, enhance, and interconnect sophomore, junior, and senior level courses with the common thread of linear systems and transforms by unifying the experimentation medium. In this fashion, physical phenomenon is returned to the forefront of engineering education. The laboratory features powerful Mathematica Notebooks (a form of hypertext) and interactive applications that use dedicated DSP microprocessors.

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Interactive video lessons for electromagnetic education

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computer Applications in engineering Education 1993年第2期1卷 147-147页

作者： Iskander, M.F. Reed, T. Breen, J. III. Electrical Engineering Department University of Utah Salt Lake City Utah 84112 Dr. Iskander edited two special issues of theJournal of Microwave Power one on “Electromagnetics and Energy Applications” March 1983 and the other on “Electromagnetic Techniques in Medical Diagnosis and Imaging” September 1983. He authored one book onElectromagnetic Fields and Waves published by Prentice Hall 1992 he edited theCAEME Software Book Vol. I 1991 and coedited two books onMicrowave Processing of Materials one published by the Materials Research Society in 1991 and the second to be published in 1992. The holder of seven patents he has contributed 16 chapters to eight research books published more than 100 papers in technical journals and made numerous presentations in technical conferences. In 1983 he received the College of Engineering Outstanding Teaching Award and the College Patent Award for creative innovative and practical invention. In 1984 he was selected by the Utah Section of the IEEE as the Engineer of the Year. In 1984 he received the Outstanding Paper Award from the International Microwave Power Institute and in 1985 he received the Curtis W. McGraw ASEE National Research Award for outstanding early achievements by a university faculty member. In 1991 he received the ASEE George Westinghouse National Award for innovation in Engineering Education. He also received the 1992 Richard R. Stoddard Award from the IEEE EMC Society. In 1986 Dr. Iskander established the Engineering Clinic Program in the College of Engineering at the University of Utah. Since then the program has attracted more than 45 research projects from 18 different companies throughout the United States. He is also the director of the NSF/IEEE Center for Computer Applications in Electromagnetics Education (CAEME). He coorganized symposia on “Microwave Processing of Materials” held in conjunction with Materials Research Society meetings Springs of 1990 and 1992 in San Francisco. He also organized several workshops and special

With the availability of a large number of software packages for electromagnetic (EM) education through the national computer Applications in Electromagnetic Education (CAEME) Center [1] and other individual efforts, there have been some concerns regarding the ability to integrate this software effectively in routine classroom teaching. Basically, congested EM curricula do not provide instructors with sufficient time to include software demonstrations and simulations during class periods. It is also not clear whether students will be able, adequately and independently, to understand basic underlying concepts and physical phenomena from visualization of colorful graphics and from the output of performed simulations. To help integrate available EM software in classroom teaching for both instructor use and student independent study, CAEME developed three interactive video lessons for student instruction. Interactive media lessons integrate and allow individuals to interactively manipulate information from multimedia such as video, software, and animated graphics, and also include instructional information such as quizzes and tutorials. In this article, we present the features of three interactive video lessons in EM developed by CAEME. These lessons include tutorials, simulations from CAEME software and videos, and quizzes to evaluate student understanding. The lessons use animated graphics illustrating specific dynamic phenomena and specific measurement procedures. They also keep a record of student quiz scores for instructor use. These, as well as other features of the three developed interactive video lessons, and the software and hardware requirements for developing such lessons, will be described.

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