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A DISTRIBUTED MEDIA ACCESS PROTOCOL FOR PACKET RADIO NETWORKS AND PERFORMANCE ANALYSIS .2. NETWORK SET-UP TIME AND DATA RATE

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INTERNATIONAL JOURNAL OF COMMUNICATION systemS 1995年第1期8卷 49-63页

作者： POND, LC LI, VOK Communication Sciences Electrical Engineering Systems University of Southern California Los Angeles CA 90089-2565 U.S.A. Lawrence C. Pond received the M.Sc. and Ph.D. degrees in electrical engineering from the University of Southern California in 1983 and 1990 respectively. Dr. Pond is currently a scientist at Hughes Space and Communications Company having joined in 1980. He has worked in the fields of communication system design mobile communication network and spacecraft payload design. He is currently working on the development of satellite-based ATM transport and switching architectures for BISDN and Defense Information System Network amlications. Dr. Pond is a member of IEEE. Victor O. K. Li was born in Hong Kong in 1954. He received his SB SM and Sc.D. degrees in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology Cambridge Massachusetts in 1977 1979 and 1981 respectively. Since February 1981 he has been with the University of Southern California (USC) LOS Angeles California where he is Professor of Electrical Engineering and Director of the USC Communication Sciences Institute. He has published 150 technical papers and has lectured and consulted extensively around the world. His research interests include high-speed communication networks personal communication networks intelligent networks distributed databases queueing theory graph theory and applied probability. Dr. Li is very active in the Institute of Electrical and Electronic Engineers (IEEE) having been a member of the Computer Communications Technical Committee since 1983 and having served as Chairman from 1987–1989. He served as Chairman of the Los Angeles Chapter of the IEEE Information Theory Group from 1983–1985. He is the Steering Committee Chair of the International Conference on Computer Communications and Networks (IC3 N) General Chair of the 1st Annual IC3N held in San Diego California in June 1992 General Chair and Technical Program Chair of the 4th IEEE Workshop on Comp

In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tools are developed to determine the virtual circuit and network set-up times in terms of the channel bandwidth allocated to establish and maintain the network. The tools are then extended to include the effects of user mobility. Then these results are combined with the network capacity results of Part 1 to analyse the trade-off between the data rate and set-up time of the network. Next a hierarchical architecture is proposed and the network data rate versus set-up time trade-off of this architecture is analysed using these tools. This architecture is shown to both provide a higher data rate and establish faster than flat networks of the same number of nodes.

关键词： PACKET RADIO NETWORK EPLRS DISTRIBUTED NETWORK TDMA VIRTUAL CIRCUITS MULTIHOP NETWORK BOUNDED DELAY MOBILITY NETWORK SET-UP TIME HIERARCHICAL NETWORK NETWORK DATA RATE

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Windows computer laboratory as a tutorial for undergraduate electromagnetics

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Computer Applications in engineering Education 1995年第3期3卷 183-183页

作者： McCulloch, J. Keddy, W.A. Stuchly, M.A. University of Victoria Department of Electrical and Computer Engineering University of Victoria Victoria British Columbia Canada Janet McCulloch:is a native of Toronto Canada where she briefly attended both York University and the University of Toronto before she set off on a year-long adventure through the Middle East and North Africa. When she returned to Canada she relocated to California. She spent a number of years living both in Los Angeles and coastal Northern California interspersed with several extended trips through the United States Mexico and Central America. Ms. McCulloch moved to Victoria British Columbia in 1989 and a year later registered in the cooperative education program in Electrical Engineering at the University of Victoria. She is presently in the fifth and final year of the program and has her sights set on graduate school. Besides the work described in this article she has been very much involved in the use of technology to assist in the delivery of curriculum at the senior secondary level. She lives on a country property a half-hour from the University with her husband her horse and three cats. W. Alfred Keddy:is an applications programmer/analyst for the Department of Electrical and Computer Engineering at the University of Victoria. He received a BEng (1988) in Electrical Engineering and an MASc (1994) from the University of Victoria. His research interests include distributed systems image processing local area networks VLSI and DSP system design for computation and communication and human–computer interface design. Maria A. Stuchly:received an MSc in Electrical Engineering in 1962 from Warsaw Technical University and a PhD in Electrical Engineering from the Polish Academy of Sciences in 1970. Between the years of 1962 and 1970 she was with the Warsaw Technical University an Institute of the Polish Academy of Sciences. After immigrating to Canada during 1970 her first position was with the University of Manitoba. In 1976 she became employed by the Bureau of Radi

Contents and implementation of a computer laboratory for undergraduate electromagnetics are described. The laboratory consists of four 3-hour sessions covering vector calculus, Maxwell's equations (integral and differential forms), wave propagation in materials, and wave behavior at planar interfaces. Each session contains theory (in the Help file), animations (where relevant) and a quiz. The program runs on IBM compatible 486-based PCs in a Windows environment and uses the Borland C ++ 4.0 compiler.

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STOCHASTIC CHARACTERIZATION OF SPACE-TIME PRECIPITATION - IMPLICATIONS FOR REMOTE-SENSING

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ADVANCES IN WATER RESOURCES 1994年第1-2期17卷 47-59页

作者： VALDES, JB HA, EH YOO, C NORTH, GR [a]Department of Civil Engineering and Climate System Research Program Texas A&M University College Station Texas 77843-3136 USA[c]Department of Civil Engineering Texas A&M University College Station Texas 77843-3136 USA[b]Climate System Research Program Texas A&M University College Station Texas 77843-3150 USA

In this paper the characterization of the space-time spectral characteristics of tropical rainfall fields are studied directly from measurements from ground sensors and by using three stochastic models. The characterization of the spatial-temporal spectra is important for the design of satellite missions and to determine the bias in ground truth experiments. To carry out the latter a scheme is used to compare contemporaneous measurements of rain rate from a single-field-of-view estimate, based on a satellite remote sensor such as a microwave radiometer, with those coming from a point raingauge. Using this scheme the errors are computed for several observed rainfall fields, either from the data estimated spectra or from analytically derived and characterized ground measurements. This quantification provides a lower bound to total errors, since perfect instruments are assumed in this work, and it helps in terms of isolating and evaluating typical biases that might be contaminating retrieval algorithms.

关键词： Precipitation (meteorology)

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Paper #16: . DESIGN CONSIDERATIONS INTEGRATING ETC GUN systemS ABOARD NAVAL SURFACE COMBATANTS

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Naval Engineers Journal 1994年第4期106卷

作者： Guy F. Grater Steven Fagan Thomas E. Doran Gary L. Carle Program Manager ETC Gun Technology Program NSWC Dahlgren Division AEGIS Surface Warfare System Engineer AEGIS System Engineering Branch Combat Systems Department

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Elements of an Id-Loop Engine

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IFAC Proceedings Volumes 1994年第8期27卷 761-766页

作者： M. Snaprud H.P. Jörgl H. Kaindl Technical University Vienna. Institute of Machine and Process Automation. Gußhausstr 27-29. A-1040 Vienna. Austria Tel. : +43-1-58801-3763. Fax: +505 92 64 Siemens Austria Program and System Engineering A-1030 Vienna Austria Tel. : 43-1-71600-288. Fax: 43-1-71600-323

A large number of commercially available software packages for CACE are in use today, many of which can be used for system identification. The numeric procedures provided in these packages are reasonably stable and reliable. However, engaging such tools requires the user to provide all the necessary strategic knowledge. In case something goes wrong, or the package produces unexpected results, the user has to come up with a remedy with very little or no support from the tool. Several versions of the procedure of system identification have been proposed in the literature. For the purpose of providing support for the use of a tool for system identification our ID-loop was designed, a representation of the procedure of system identification, in the form of a sequence of subtasks related to required and generated data. In this paper we describe bow the ID-loop can be used as a plan for doing system identification. In particular, we describe how a simple interpreter uses the ID-loop and the knowledgebase status during a session to determine what to do next. Since the interpreter works only with symbolic data, a mapping between the real-world data and symbolic data is necessary. For this purpose we use data abstraction . In order to manage the rejection of hypothesises we introduce data retraction .

关键词： system identification knowledge-based systems strategic knowledge ID-loop

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SHIP SELF-DEFENSE PERFORMANCE ASSESSMENT METHODOLOGY

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NAVAL ENGINEERS JOURNAL 1994年第3期106卷 208-219页

作者： POLK, J MCCANTS, T GRABAREK, R James Polk:is currently a principal financial and technical advisor for PRC Inc. He is working in support of PEO (TAD) Ship Self-Defense Program in several areas including performance assessment. He retired from the Navy in 1991 after several years at sea and various material command assignment including command of Caron (DD-970) and Aegis technical director. He is an ASNE Member who has an MS in physics from the Naval Postgraduate School. He graduated from the University of Notre Dame with a BS in civil engineering and earned his commission through the NROTC program there. Thomas H. McCants Jr.:is currently a principal system engineer in the ship defense department of the Naval Surface Warfare Center Dahlgren Division. He is supporting the PEO (TAD) in systems engineering and analysis and is supporting the Office of Naval Research in a 6.2 Ship Self-Defense program. He was previously the lead lab program manager for STANDARD Missile led the Aegis Systems Analysis and T&E organization at NSWC was Phalanx CIWS lead lab program manager and was the air target vulnerability program manager at the Center. In 1977–78 Mr. McCants was the NSAP science advisor to COMOPTEVFOR Norfolk. He graduated from VPI&SU with a BS in aerospace engineering and is pursuing a MS in systems engineering from VPI&SU. Robert Grabarek:is currently an electronics engineer in the requirements and analysis branch of the Ship Self-Defense Program Office. He is a 1981 graduate of the U.S. Naval Academy and served six years on active duty as a surface warfare officer. He has earned his MA in operations research and industrial engineering from VPI&SU.

Robust ship AAW defense capability is a priority requirement that enables Naval Forces to conduct joint expeditionary force operations in littoral environments. As an aid to achieving this capability for all ship classes, the Navy has reorganized its management of ship defense. A major focus of these efforts is the development of a fully automatic, integrated combat system for non-Aegis ships which is based on coordinated detection, control, and hard kill/electronic warfare (HK/EW) engagement functions. A phased approach to attaining this fully integrated capability has been established which includes major element upgrade introduction when technology and budget permit. This paper describes the ship self-defense performance assessment methodology which has been adopted to support the review and decision process for future planning and budgeting. This process is a continuation and refinement of that used to provide data for the Office of the Secretary of Defense Fall 1991 Conventional systems Committee Ship Self-Defense Review. The performance assessment methodology starts with definition of survivability requirements by ship class, combat system configurations, Anti-Ship Missile threat, and operational scenario. Viable self-defense system element options are then identified. The capability of these options are then characterized for input into ship level performance prediction models. Three partitions of performance prediction modeling are made: hard kill elements only, electronic warfare element only, and integrated HK/EW. The most significant accomplishment of this effort, beyond providing data to support programmatic decision, has been the creation of a truly integrated HK/EW surface ship combat system model that interleaves HK and EW timelines and allows parametric variation to evaluate options. Because of classification, only generic examples of numerical result will be presented. However, the procedures for establishing the modelling process, prioritization of

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COMBAT system MAINTENANCE CENTRAL (CSMC)

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NAVAL ENGINEERS JOURNAL 1994年第1期106卷 47-53页

作者： SACKETT, WH DORMAN, ML Colonel William H. Sackett:served over 30 years in the United States Marine Corps earning during his career a BS degree in mechanical engineering through a transitory combination of university studies and military schools. During the period June 1976 to December 1988 he participated as a principal member of the RCA AEGIS Ship Combat System Readiness Development Team. His activities included the conduct of feasibility studies and the identification of physical characteristics in the development of a combat system readiness concept for implementation in the Combat System Maintenance Central of the AEGIS ship. Marshall L. Dorman Jr.:received his BS degree in mechanical engineering from the University of Washington in 1959. He worked at the Boeing Company in Seattle on various airplane/missile programs and the Navy's PHM hydrofoil program. He was employed by RCA on the Aegis program from June 1976 until February 1988 as a lead engineer in arrangements for the Aegis CG 47 class cruisers the CGN-42 proposal and the strike cruiser proposal. For efforts in this position he received the Aegis Excellence Award. Following the Aegis program he returned to Boeing and was employed in system engineering as a configurator on the Navy E-6 AW ACS and the F22 advanced tactical fighter programs. Marshall a life member of ASNE the Naval Institute and the Navy League was a qualified engineering duty officer in the Naval Reserve and served several training duty tours with NavSea in Washington DC. He is also a registered professional engineer in Washington State and was a registered professional engineer while at RCA in New Jersey.

Combat system maintenance central (CSMC) is an innovative manned space concept. New to the Navy, it is proving to be a major asset to the AEGIS cruisers and destroyers. ''The primary mission of the CSMC is to provide an organized environment for the coordination and control of operability testing and maintenance, and the collection, evaluation, and timely dissemination of combat system operational readiness information. CSMC grew from a minimal size, ''broom closet'' concept (see Figure 1) to one of a critically manned operating area. The growth and evolution of the concept was a major challenge. Several iterations were subjected to intensive design reviews until the CSMC concept was finally fully approved by the Navy (see Figure 2). Combat system contractor personnel working closely with NavSea PMS 400, Aegis program office, personnel were responsible for the development of the CSMC. The space was configured to meet and has met all operational requirements imposed.

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CONTRAROTATING ELECTRIC DRIVE FOR ATTACK SUBMARINES

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NAVAL ENGINEERS JOURNAL 1994年第2期106卷 45-50页

作者： DUTTON, JL The Author:is an electrical engineer with NNS ‘s advanced propulsion technology department. This group applies current and future technologies to naval and marine propulsion plant designs. Dutton received his BS degree in electrical engineering from the University of Virginia in 1978 and began working at NNS later that year. His previous tasks have included the AN/BSY-2 Combat System in the NNS Seawolf program and project leader of the NNS superconductivity program. An officer of the Cryogenic Society of America (Hampton Roads Chapter) he is presently working on advanced motor/generator designs and electrical distribution systems for shipboard applications at NNS.

This paper addresses certain issues relating to the viability of contrarotating (CR) electric drive for attack submarines. Topics include CR propulsion's potential benefits, electric drive advantages, and combining contrarotation with electric drive engine room concepts. CR propellers provide propulsive coefficient (PC) increases compared to open-type and performance-enhanced single propellers. The maximum submarine propulsion plant power capacity could therefore be reduced with this PC increase, potentially resulting in a smaller, lighter propulsion plant. This paper concludes, however, that contrarotation shows no propulsion plant weight savings against electric drive attack submarines with performance-enhanced single propeller designs. Weight improvements in the power generation plant and certain steam plant and electric plant systems are offset by weight increases from the additional shafting and bearing requirments for the CR shaft. Contrarotation is currently more advantageous for nonnuclear ships, where significant fuel savings are achievable with its higher PC.

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ACQUISITION REFORM AND BEST PRODUCT PROCUREMENT - AN engineering VIEW

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NAVAL ENGINEERS JOURNAL 1994年第6期106卷 41-57页

作者： FISHER, DA SKOLNICK, A He has been involved with several weapon system developments. Among these were the Trident II fire control and navigation systems the BSY-I Anti-Submarine Warfare System and the Navy standard computers (UYK44 and EMSP). He served as manager of the Digital Circuits Engineering Branch and was then appointed as manager of the Automatic Test Equipment (ATE) Technology Division. As manager of the ATE Technology Division he was responsible for the SP-23 Fire Control System Support Project the SP-24 Navigation Project and the Fleet Progressive Maintenance Program (2M/ATE). This Division was responsible for selection and application of electronic product technology and for developing fleet test and repair techniques. He holds a B.S. in Electrical Engineering from the University of Evansville and is currently pursuing a Masters of Public Administration at Indiana University-Purdue University Indianapolis. Dr. Alfred Skolnick:retired from the Navy in 1983 with the rank of captain. He is president of System Science Consultants (SSC) specializing in strategic planning technical program definition technology assessment and engineering analyses on selected matters of national interest. Dr. Skolnick taught mathematics and management sciences at University of Virginia and Marymount University. He is adjunct faculty at Northern Virginia Community College. From 1985 to 1989 he was president of the American Society of Naval Engineers. In the Navy he served at Applied Physics Laboratory/The Johns Hopkins University then aboard USSBoston(CAG-1) and played leading roles in several weapon system developments inertial navigation (Polaris) deep submergence (DSRV) and advanced ship designs (SES). He later was director Combat System Integration Naval Sea Systems Command and head Combat Projects Naval Ship Engineering Center. In 1975 he became a major project manager and led the Navy's High Energy Lasers Program in 1981 he was assigned all Navy Directed Energy Weapons development efforts. He was vice president advanced tech

The military services are being moved in the direction of performance-based specifications and standards. They are being steered against dictating ''how to'' produce an item since such action forecloses on the ability to gain access to components or technology that may have a commercial equivalent. Why should the engineering community embrace the new approach? Aside from the obvious weight of it being approved policy, therefore currently mandated, it warrants examination because it is the correct approach at this time when applied to appropriate products. Military specifications and standards are to be displaced then, by acceptable alternative contractor design solutions. Industry bidders will be allowed to propose the particular design details, permitting procurement flexibility by contractually citing only system level or interface requirements, both physical and functional. Hopefully, this can broaden the industrial base and increase competition with reduced costs to follow. Conceptually, the approach appears both performance-sensible and cost-attractive (there are, of course, consequent risks) but how does implementation proceed? Is it possible to pursue the goals envisioned along paths that are not in themselves experimental? Can the American postulate, minimal loss of life and limb to U.S. military people, continue to be honored? Experience and track record elsewhere imply encouraging possibilities in select situations-useful prospects are identified and discussed in practical terms.

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MINING GOLD IN THE MIDWEST

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NAVAL ENGINEERS JOURNAL 1994年第1期106卷 137-140页

作者： SKOLNICK, A The Author:is president of System Science Consultants (SSC) specializing in strategic planning technical program definition and engineering analyses on selected matters of national interest. Dr. Skolnick teaches mathematics and management sciences at Marymount University and Northern Virginia Community College. From 1985 to 1989 he was president of the American Society of Naval Engineers. He has been helping the Congressional Office of Technology Assessment in evaluating civil-military integration and dual-usage opportunities. He is active in advancing national efforts to improve the teaching of mathematics and science in our elementary and secondary schools he serves on the Board of Directors of the National Coalition of Engineering Societies for Precollege Mathematics and Science.

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