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Governing Equation and Mathematical Simulation on Ablation and Transpiration Control

Journal of Systems engineering and Electronics 1992年第3期3卷 44-58页

作者： Yang Xueshi and Gao Wei Beijing Institute of Electromechanic System engineering, P.O. Box 3924, Beijing 100854, ChinaYuan Zhaoding Institute of computer application and Simulation Technology, Beijing 100854Xu YanhouDepartment of Modem Mechanics, University of science and Technology of China, Hefei 230026 Beijing Institute of Electromechanic System Engineering P.O. Box 3924 Beijing 100854 China Institute of Computer Application and Simulation Technology Beijing 100854 Department of Modern Mechanics University of Science and Technology of China Hefei 230026

This paper represents a physical model of two -dimensional transpiration cooling control system with surface heating and ablating. The governing equation is derived and the third boundary conditions are given. They constitute a two -dimensional variable -domain distributed parameter control system in which the control parameter appears in both the governing equation and the boundary conditions. Applying time semi-step alternating direction method to difference this mathematical model, the tridiagonal difference equations are obtained. For a flying shell of electromagnetic railgun, the mathematical simulation results agree with the realistic physical process, and the control parameter not only can control the temperature of heat shield, but also can control the boundary motion effectively.

关键词： Transpiration Variable-boundary Heat transfer Mathematical simulation.

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Peak-current programmed dynamic current distribution control for converters connected in parallel

Peak-current programmed dynamic current distribution control...

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International Conference on Industrial Electronics, Control and Instrumentation

作者： K. Siri T.-F. Wu C.Q. Lee Illinois Power Application Center Department of Electrical Engineering and Computer Science University of Illinois Chicago Chicago IL USA

A current mode control scheme for load sharing power converter systems with dynamic current distribution is proposed. These converters may be driven by different sources and possess different power ratings. With this control feature, the system is able to dynamically distribute the total output current among the power converters according to these ratings. Converters with higher power ratings will deliver larger portions of the total output current. The current distribution control algorithm and the system stability are described and analyzed in detail. These analyses and descriptions are confirmed with computer simulation results.< >

关键词： Current distribution Control systems Collision mitigation Voltage control Pulse width modulation Algorithm design and analysis Automatic control application software Stability analysis computer simulation

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COMPARISON OF DOWNHOLE AND SURFACE SAMPLING FOR THE DETERMINATION OF VOLATILE ORGANIC-COMPOUNDS (VOCS) IN GROUND-WATER

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GROUND WATER MONITORING AND REMEDIATION 1992年第1期12卷 126-133页

作者： ROSEN, ME PANKOW, JF GIBS, J IMBRIGIOTTA, TE Michael E. Rosen received his B.A. in chemistry from the State University of New York at Binghamton in 1981 and a Ph.D. in environmental science and engineering from the Oregon Graduate Institute in 1988. His research interests include trace environmental analysis of organic compounds. He is now manager of the Voluntary Cleanup Section of the Oregon Department of Environmental Quality (Environmental Cleanup Division 811 S.W. 6th Ave. Portland OR 97204) where he is working to develop streamlined procedures and processes for the investigation and cleanup of hazardous substance sites. James F. Pankow is professor and chairman of the Department of Environmental Science and Engineering at the Oregon Graduate Institute (Oregon Graduate Institute of Science and Technology Department of Environmental Science and Engineering 19600 N.W. von Neumann Dr. Beaverton OR 97006–1999). He received his B.A. in chemistry in 1973 from the State University of New York in Binghamton and his Ph.D. in environmental engineering science from the California Institute of Technology in Pasadena California in 1979. His group is involved in the study of the physical and chemical processes affecting the behavior of organic and inorganic chemicals in the environment. This work includes the development and application of sensitive analytical methods for the determination of trace organic contaminants in ground water systems. Jacob Gibs is an environmental engineer with the U.S. Geological Survey Water Resources Division (810 Bear Tavern Rd. Ste. 207 West Trenton NJ 08628). He received a B.S. in mechanical engineering in 1968 an M.S. in environmental engineering in 1975 and a Ph.D. in environmental engineering in 1983 all from Drexel University Philadelphia Pennsylvania. He is currently project chief of a study on representative sampling of ground water for trace levels of organic compounds. His research interests include evaluating ground water sampling techniques and devices for purgeable organic compounds design of sampling

The relative precision and accuracy of sampling and analysis methods for the determination of trace concentrations of volatile organic compounds (VOCs) in ground water were compared. Samples were collected from a well containing nanogram-per-liter (ng/L) to microgram-per-liter (mu-g/L) levels of VOCs. A Keck helical rotor submersible pump was used to collect samples at the surface for analysis by purge and trap (P&T) and for analysis by adsorption/thermal desorption (ATD). Downhole samples were collected by passing water through an ATD cartridge. Although slight spontaneous bubble outgassing occurred when the water was brought to the surface, the relative precisions and comparabilities of the surface and downhole methods were generally found to be equivalent from a statistical point of view. A main conclusion of this study is that bringing sample water to the surface for placement in VOC vials (and subsequent analysis by P&T) can be done reliably under many circumstances. However, care must still be taken to prevent adsorption losses and cross contamination. Samples subject to strong bubble outgassing will need to be handled in a special fashion (e.g., by downhole ATD) to minimize volatilization losses. Additionally, the higher sensitivity of the ATD method allows lower detection limits than are possible with P&T. For example, several compounds present at the ng/L level could be determined with confidence by ATD, but not by P&T.

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A high-speed packet switch architecture with a multichannel bandwidth allocation

A high-speed packet switch architecture with a multichannel ...

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IEEE Annual Joint Conference: INFOCOM, IEEE computer and Communications Societies

作者： K. Ohtsuki K. Takemura J.F. Kurose H. Okada Y. Tezuka College of Liberal Arts Kobe University Japan Mitsubishi Electric Microcomputer Application Software Company Limited Japan Department of Computer and Information Science University of Massachusetts USA Faculty of Engineering Osaka University Japan

A novel packet switch architecture is proposed based on a channel grouped virtual circuit (CG-VC) scheme for high-speed communication networks. The case is considered in which there are several parallel channels between two switching nodes. The CG-VC scheme allows a packet to select an available channel in such a way as to avoid congested channels using a simple, hardware-based, self-routing mechanism. As a result, the architecture provides efficient channel use and low switching delay. The performance of the proposed switch is evaluated by simulation. The results show the proposed switch significantly improves channel utilization and switching delay compared with conventional single-channel allocation transmission policies.< >

关键词： Packet switching Channel allocation Optical switches Routing Delay computer architecture Optical fibers Bandwidth Contracts Educational institutions

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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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computer-SYSTEM ARCHITECTURE CONCEPTS FOR FUTURE COMBAT SYSTEMS

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NAVAL ENGINEERS JOURNAL 1990年第3期102卷 43-62页

作者： ZITZMAN, LH FALATKO, SM PAPACH, JL Dr. Lewis H. Zitzman:is the group supervisor of the Advanced Systems Design Group Fleet Systems Department The Johns Hopkins University Applied Physics Laboratory (JHU/APL). He has been employed at JHU/APL since 1972 performing applied research in computer science and in investigating and applying advanced computer technologies to Navy shipboard systems. He is currently chairman of Aegis Computer Architecture Data Bus and Fiber Optics Working Group from which many concepts for this paper were generated. Dr. Zitzman received his B.S. degree in physics from Brigham Young University in 1963 and his M.S. and Ph.D. degrees in physics from the University of Illinois in 1967 and 1972 respectively. Stephen M. Falatko:was a senior engineering analyst in the Combat Systems Engineering Department Comptek Research Incorporated for the majority of this effort. He is currently employed at ManTech Services Corporation. During his eight-year career first at The Johns Hopkins University Applied Physics Laboratory and currently with ManTech Mr. Falatko's work has centered around the development of requirements and specifications for future Navy systems and the application of advanced technology to Navy command and control systems. He is a member of both the Computer Architecture Fiber Optics and Data Bus Working Group and the Aegis Fiber Optics Working Group. Mr. Falatko received his B.S. degree in aerospace engineering with high distinction from the University of Virginia in 1982 and his M.S. degree in applied physics from The Johns Hopkins University in 1985. Mr. Falatko is a member of Tau Beta Pi Sigma Gamma Tau the American Society of Naval Engineers and the U.S. Naval Institute. Janet L. Papach:is a section leader and senior engineering analyst in the Combat Systems Engineering Department Comptek Research Incorporated. She has ten years' experience as an analyst supporting NavSea Spa War and the U.S. Department of State. She currently participates in working group efforts under Aegis Combat System Doctrin

This paper sets forth computer systems architecture concepts for the combat system of the 2010–2030 timeframe that satisfy the needs of the next generation of surface combatants. It builds upon the current Aegis computer systems architecture, expanding that architecture while preserving, and adhering to, the Aegis fundamental principle of thorough systems engineering, dedicated to maintaining a well integrated, highly reliable, and easily operable combat system. The implementation of these proposed computer systems concepts in a coherent architecture would support the future battle force capable combat system and allow the expansion necessary to accommodate evolutionary changes in both the threat environment and the technology then available to effectively counter that threat. Changes to the current Aegis computer architecture must be carefully and effectively managed such that the fleet will retain its combat readiness capability at all times. This paper describes a possible transition approach for evolving the current Aegis computer architecture to a general architecture for the future. The proposed computer systems architecture concepts encompass the use of combinations of physically distributed, microprocessor-based computers, collocated with the equipment they support or embedded within the equipment itself. They draw heavily on widely used and available industry standards, including instruction set architectures (ISAs), backplane busses, microprocessors, computer programming languages and development environments, and local area networks (LANs). In this proposal, LANs, based on fiber optics, will provide the interconnection to support system expandability, redundancy, and higher data throughput rates. A system of cross connected LANs will support a high level of combat system integration, spanning the major warfare areas, and will facilitate the coordination and development of a coherent multi-warfare tactical picture supporting the future combatant command st

关键词： computer Architecture

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Nominal H2 Optimization and Simultaneous Stabilization: An Example of U-Parameter Design

Nominal H2 Optimization and Simultaneous Stabilization: An E...

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American Control Conference (ACC)

作者： Peter Dorato Yunzhi Li Hong Bae Park Department of Electrical and Computer Engineering University of New Mexico Albuquerque NM USA Space Science and Application Center Academia Sinica Beijing China Department of Electronics Kyungpook National University Taegu South Korea

The problem considered is that of finding a compensator for a feedback system which minimizes an H 2 -norm of a weighted sensitivity function for a nominal stable plant while preserving the stability of the feedback system when the nominal plant is perturbed to another, possibly unstable plant. It is known that the problem of simultaneous stabilization of two plants can be reduced to an interpolation problem with units in H ∞ . The interpolating unit may be parameterized in terms of an arbitrary strongly bounded real function U(s). This parameterization of robustly stable compensators in terms of bounded real functions is referred to as U-parameterization, and represents a direct extension of the Q-parameter theory used for the design of nominally stable feedback systems. We propose here the use of this free parameter to minimize H 2 -norm for a nominal plant.

关键词： Interpolation Feedback Stability Robustness Poles and zeros Hydrogen application software Sensor systems and applications Hydraulic actuators Nonlinear systems

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ROBOTIC AND ARTIFICIAL-INTELLIGENCE SYSTEMS FOR THE NAVAL OPERATIONAL ENVIRONMENT

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NAVAL ENGINEERS JOURNAL 1987年第4期99卷 74-86页

作者： HOGGE, SM The author earned her bachelor's of science degree in industrial engineering and operations research from Virginia Polytechnic Institute and State University. While at Virginia Tech she worked in the Robotics Laboratory supporting robotics research sponsored by the National Bureau of Standards. She completed her master's of science in computer science at The Johns Hopkins University. Until this past March Miss Hogge worked at the Naval Surface Weapons Center in Silver Spring Maryland. Her duties included the application of robotics and artificial intelligence to explosive ordnance disassembly mobile robotics remote controlled fire fighting vehicles human factors expert systems computer enhanced decision-making aids and hardware security. She published a two-volume study discussing shipboard operational applications of robotics and AI. In addition her publications include nine recent journal articles on robotics and computer security. Miss Hogge is currently employed with Automaker Inc. in Houston Texas. Her current role is manager of all government related robotic operations and vision systems. Miss Hogge's projects at Automaker include: an explosive ordnance disassembly gantry robot system a vision inspection system to examine bearings 3-part camouflage spray painting an investigation of the use of robotic welding in Navy shipyards and rework facilities and epoxy spray painting of missile radomes.

Due to demographical factors, there will be a 25% decline in the national labor pool of eligible 17 to 21 year old men by 1992. As the Navy faces fierce competition with other services and private industry for the dwindling personnel resources of the nation, efforts must be made to consider automating certain tasks, especially those that are hazardous, boring, and labor intensive onboard ships at sea. The Surface Ship Continuing Concept Formulation (CONFORM) Program (SEA-5014) sponsored the Naval Surface Weapons Center's Robotics Laboratory to identify potential applications of robotic and artificial intelligence systems to operation and mission activities for shipboard use. The results of the investigation concerning applications of robotics to automate the aforementioned tasks are presented. Changes in current manning levels for selected tasks and ship classes, i.e., CVs, CVNs, LPDs, LPNs, and auxiliaries are examined. Future ship designs incorporating robotics, such as the advance based repair (ABR) ship are discussed. Twenty-four applications were cited in the study which include a remote controlled vehicle for flight deck operations, limited tasks in biological, chemical, and radiation environments, computer aided command decision aids, ordnance handling, undersea search, recovery, and salvage, and ventilation duct cleaning. Four of the applications and their subsequent hardware fruition will be discussed.

关键词： ROBOTICS

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A METHODOLOGY FOR SETTING COMBAT SYSTEM REQUIREMENTS

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NAVAL ENGINEERS JOURNAL 1985年第4期97卷 274-278页

作者： MENSH, DR The Author 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 system analysis and computer simulation. He has been employed at the Naval Surface Weapons Center White Oak Laboratory Silver Spring Md. for the past eighteen years in the areas of weapon system analysis and the development of weapon system simulations. Since 1978 he has been involved in the development of simulation tools that can be applied to the solution of shipboard combat system architecture and engineering problems. Currently at the White Oak Laboratory he is responsible for the application of and further development of the single ship combat system simulation.

This paper describes a methodology for setting combat system requirements for all ship classes. The requirements are determined from a battle group perspective. The methodology uses ship damage as a measure of effectiveness for setting combat system requirements. The ship damage data used was derived from the Navy tactical game (NAVTAG). The methodology that determines ship class combat system requirements consists of a set of logical steps that are iterative by design. It provides insight and valid estimates of numerical measures of defined force requirements at several levels. This process is not trivial; the expected level of effort could be significant. The method consists of five basic stages considered necessary to achieve valid results. These stages are (1) determination of force level requirements, (2) determination of force level capability, (3) analysis of force level capability, (4) determination of class requirements by battle overviews, and (5) determination of class requirements — overall. The methodology was used by the combat system master plan (CSMP) manager for determining top level combat system requirements for individual platforms in a battle group. In addition, once levels of combat system performance have been defined, this methodology generates a quantitative data base that becomes a useful tool in ship combat suite selection. Once alternate combat system suites have been defined, these suites can be analyzed in terms of combat system performance capability versus cost.

关键词： NAVAL WARFARE

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FIRE MAIN CONTROL

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NAVAL ENGINEERS JOURNAL 1985年第6期97卷 35-48页

作者： MALKOFF, DB MOY, MC WILLIAMS, HL Dr. Donald B. Malkoff majored in physics as an undergraduate at Harvard University. He received an M.D. degree from the University of Pittsburgh School of Medicine in 1960. This was followed by an internship and residency in neurology at University Hospital in Ann Arbor Michigan. He spent several years at the National Institutes of Health engaged in gerontology research has practiced and taught clinical neurology and in 1983 received an M.S. degree in computer science at the University of California San Diego. Currently Dr. Malkoff is employed by the Navy Personnel Research and Development Center in San Diego California where he is senior investigator in a human factor/computer display-and-control project involving the DDG-51 gas turbine propulsion unit. He is a member of the American Academy of Neurology the Society for Neuroscience the American Association for Artificial Intelligence and the Association for Computing Machinery. Dr. Malkoff is certified by the American Board of Psychiatry and Neurology has taught computer science at UCSD and published in several research areas including magnetoencephalography and electron microscopy. His basic interests are in the areas of artificial intelligence and learning expert systems particularly as they apply to the problems of fault-detection and control. Dr. Melvyn C. Moy received his undergraduate training in mathematics and chemistry at the University of Texas Austin. He studied experimental psychology at the University of Wisconsin Madison receiving his M.S. in 1970 and Ph.D. in 1972. He served as an assistant professor at the University of South Dakota where he taught experimental design and methodology for a year before joining the Navy Personnel Research and Development Center in 1973. His work and research since then spans across many application areas such as the development of manpower planning models for the Navy the design of operational decision aids the human engineering of interactive large-scale war gaming systems and the evaluation o

The ship fire main has undergone considerable development throughout the past 2,000 years, resulting in a system that is critical both for normal ship function and for ship survivability in emergencies. Because of its complexity, the modern firemain system is highly vulnerable to malfunction and to damage during combat. Firemain fault detection and fault recovery are currently conducted manually by damage control teams. The advantages and disadvantages of this method are discussed, and alternative methods of fault detection and recovery are explored. An interactive computer program is introduced which uses central control over remotely situated valves to facilitate fault detection and recovery, significantly reducing recovery-time and manpower requirements. These reductions may result in savings of lives, ship systems, and ships themselves. The computer program is based upon an algorithm which is, in effect, a prescription that can be followed manually by the operator or be completely automated. The color graphic display which is used for monitoring can also be utilized for the training of damage control operators or for the evaluation of other algorithms for firemain control. Alternative firemain hardware and configurations could lead to even more efficient methods of fault detection and recovery as well as improved firemain water supply management in general.

关键词： NAVAL VESSELS

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