作者:
Okano, KHigashino, TTaniguchi, KMemberFaculty of Engineering Science
Osaka University Toyonaka Japan 560 Teruo Hipshino received his B.E.
M.E.and Ph.D. degrees in Information and Computer Sciences from Osaka University Osaka Japan in 1R9 1981 and 1984 respectively. He joined the Faculty of Osaka University in 1984. Since 1991 he has been an Associate Professor in the Department of Information and Computer Sciences at Osaka University. In 1990 he was a Visiting Researcher of Dept. I.R.O. at University of Montreal Canada. His current research interests include design and analysis of distributed systems specification and verification of communication protocols and formal approach of program design. He is a member of IEEE-CS ACMIEICE of Japanand IPS of Japan.
In this paper, new methods for providing the correctness of refinement among abstract sequential machine style programs are described. The programs are described in algebraic language ASL using some useful notions, i....
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In this paper, new methods for providing the correctness of refinement among abstract sequential machine style programs are described. The programs are described in algebraic language ASL using some useful notions, i.e., the extended projection and the valid reachability condition for each transition function. These notions allow a designer to refine a given text (program or specification) to a concrete text more freely than the text that does not use such notions. These notions can also enhance the expressive power of the text. On the other hand, these advantages would have lost half their values, if useful methods to prove the correctness of refinement among the texts using them are not found. Thus new methods for proving the correctness of the texts are proposed, and they do not require much proof loads. First, the correctness of refinement among the ASL texts with the extended projection is defined. Second, a method is proposed for proving the correctness of refinement among such texts. Also proposed is a definition of the correctness of refinement among the texts with the valid reachability conditions and a method to prove their correctness. These methods do not require more proof loads than the usual methods for the texts that do not use such notions in the abstract sequential machine style. Therefore, these methods are useful.
作者:
POND, LCLI, VOKCommunication 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. Tool...
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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.
This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the comb...
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This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLM analysis with Prony's method as well as with autoregressive moving average (ARMA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLM analysis can be accelerated by a few orders of magnitude.
作者:
Tonjes, David J.Heil, James H.Black, John A.David J. Tonjes is a doctoral candidate in coastal oceanography at the Marine Sciences Research Center
University at Stony Brook through its Waste Management Institute (Waste Management Institute Marine Sciences Research Center University at Stony Brook 11794–5000). Under a grant from the Town Board he is a technical adviser to the commissioner of waste management of the town of Brookhaven New York in solid waste planning regulatory compliance and environmental site monitoring. Tonjes has a B.A. in liberal arts from St. John's College an M.S. in computer science from New York Institute of Technology and an M.S. in technological systems management from the University at Stony Brook. James H. Heil is commissioner of waste management for the town of Brookhaven (Department of Waste Management
Town of Brookhaven 3233 Rte. 112 Medford NY 11763). Heil received a B.S. from Manhattan College and an M.S. from New York University in civil engineering and is a licensed professional engineer in New York. He is a former president of the New York State Solid Waste Management Association. John A. Black is the coordinator of the environmental science program at Suffolk County Community College (Environmental Science Program
Suffolk County Community College Selden NY 11784). He is currently the chair of the Ecology Committee of the Pine Barrens Advisory Committee for Suffolk County and is a member of the Suffolk County Pine Barrens Review Commission. Black received a B.S. in chemistry from Adephi University an M.S. in public administration from the University at Stony Book an M. S. from Hofstra University and a Ph. D. from Adlephi in marine sciences.
Stiff diagrams arc a multivariate method of analysis used to describe the chemical state of ground water. The use of Stiff diagrams to describe multiconstituent contamination sites, such as landfills, has distinct adv...
Given an arbitrary telecommunications network N our goal is to find the minimum cost for equipment which will enable N to survive an arbitrary link fault. We consider uni-directional and bi-directional ring technologi...
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Given an arbitrary telecommunications network N our goal is to find the minimum cost for equipment which will enable N to survive an arbitrary link fault. We consider uni-directional and bi-directional ring technologies. Basically, our goal is to find minimum cost ring covers for any network N, where a ring cover is a set C of rings such that every link in N is covered by (i.e. part of) at least one ring in C. If a network N is augmented with enough equipment to support a given ring cover C, it can respond to a link failure immediately (and automatically) by routing the disrupted traffic through surviving links in the ring that covers the failed link. We describe an efficient algorithm to find a minimum cost ring cover for uni-directional transmission rings under simplifying assumptions. This algorithm offers a useful heuristic for computing low cost ring covers for existing networks and actual cost functions. We also provide efficient heuristics to find nearly minimum cost ring covers for bi-directional transmission rings. We show that certain versions of the bi-directional problem are NP-complete, hence (presumably) no efficient algorithm exists that always finds a minimum cost ring cover. However, our heuristics perform well in practice.
作者:
GOUBAULT, PGREENBERG, MHEIDENREICH, TWOERNER, JPhilippe Goubault:graduated in 1983 from the “Ecole Nationale Superieure de Techniques Avancees” in Paris with a major in naval architecture. After one year of military service with the French navy
he worked as naval architect and program director for the French navy between 1984 and 1988. He was in charge of the development of AGNES200 Surface Effect Ship design which completed its sea trials in 1992. He also was responsible for the construction of five ships (four hydrographic vessels and one experimental MCM vessel) which entered service between 1988 and 1991. He has been involved in a number of projects and studies for the U.S. Navy U.S. Coast Guard and other foreign and domestic customers. At Band Lavis & Associates Inc. Mr. Goubault has expanded the computer tools used to conduct parametric analysis of advanced hullforms and has developed cost-effectiveness assessment tools and methodologies for both commercial and military ships. Mr. Goubault is a member of ASNE. Marc Greenberg:is employed as a cost analyst at the cost and economic analysis branch
systems assessment and engineering division Naval Surface Warfare Center. He provides cost estimates and analyses of Navy ship and submarine technologies and has assisted in the development of parametric cost models since 1991. Employed as an electronics engineer by the U.S. Army Information Systems Command from 1989 to 1991 he provided support in simulation design and construction of high frequency and microwave communication systems. Mr. Greenberg received his BS degree in ceramic science and engineering from the Pennsylvania State University
May 1987. He is a member of MORS. Todd Heidenreich:is employed in the design analysis and tools branch
systems assessment and engineering division of the Carde-rock Division Naval Surface Warfare Center. He is involved as a project naval architect in the conceptual design of future surface ship designs future technology impact assessments and the assessment of current domestic and foreign surface ship desig
This paper describes the results of a study undertaken to determine the impact of fuel cell technology on the design and effectiveness of future naval surface combatants. The study involved the collection of data to c...
This paper describes the results of a study undertaken to determine the impact of fuel cell technology on the design and effectiveness of future naval surface combatants. The study involved the collection of data to characterize four different fuel cell technologies: proton exchange membrane, molten carbonate, phosphoric acid, and solid oxide fuel cells. This information was used to expand current computer models to develop specific fuel cell plants that met the power requirements for several applications on a nominal 5000 Lton destroyer and a nominal 2000 Lton corvette. Each of the fuel cell technologies was incorporated into several applications aboard the destroyer and the corvette. These applications included combinations of centralized and distributed ship service power, and propulsion power. In addition, the impact of fuel cell technology was determined for a ship service power backfit option aboard a DDG-51 class destroyer. The results of the impact on the ship designs were analyzed and a military effectiveness assessment was conducted to address such issues as the impact of fuel cells on mobility, survivability, affordability, and on the environment. The paper identifies which aspects of the fuel cell technologies have the greatest impact upon the ship designs and their operational costs. Recommendations are given for future technology development efforts required to make fuel cells suitable for Navy service.
作者:
BOHM, SELHAKEEM, AKHACHICHA, MDepartment of Electrical and Computer Engineering
Concordia University 1455 De Maisonneuve Blvd. West Montreal H3A 1M8 Canada Was born in Montreal
Canada on 14 September 1966. He received the B. Eng. degree in electrical engineering from Concordia University Montreal Canada in 1989. He is at present completing the M.A.Sc. degree in electrical engineering at Concordia University. (S'75–S'79–M'79–SM'86) received the Ph.D. degree from Southern Methodist University
Dallas TX in 1979. He spent the next two years working as a Visiting Professor in Egypt after which he moved to Ottawa Canada in 1982. He assumed teaching and research positions in Carleton and Manitoba Univerities and later moved to Concordia University Montreal Canada in 1983 where he is now a Professor in the Electrical and Computer Engineering Department. He has published numerous papers in IEEE and international journals in the areas of spread spectrum and networking. He is a well-known expert in these areas and serves as a consultant to many companies. His current research interests include wide-band metropolitan networks switching architectures and performance of on-board multibeam satellites acquisitionless CDMA networks code distribution and orthogonalization of CDMA signals responsive congestion control for ATM-based networks ARQ techniques and investigation of the novel SUGAR CDMA systems in fading channels. Dr. Elhakeem is a Senior Member of the Canadian Electrical Engineering Society and Armed Forces Association. He has chaired numerous technical sessions in IEEE Conferences was the Technical Program Chairman for IEEE Montech 1986 Montreal Canada. Dr. Elhakeem is the key guest editor of theIEEE Journal of Selected Areas in Communicationsfor the May June issues 1993 covering CDMA networks. Advanced Technology & Networks
VISTAR Telecommunications Inc. Ottawa Ontario K1G 3J4 Canada An Associate Director of Advanced Technology & Networks Group
VISTAR Telecommunications Inc. Ottawa Canada. He is also an Adjunct Pr
In this paper, we study the performance of a prioritized on-board baseband switch in conjunction with a multibeam satellite handling integrated services. The services considered for the analysis include voice, video, ...
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In this paper, we study the performance of a prioritized on-board baseband switch in conjunction with a multibeam satellite handling integrated services. The services considered for the analysis include voice, video, file transfer and interactive data. The prioritized switch uses both input and output buffering, switch speed-up as well as a two-phase head-of-line resolution algorithm, in order to reduce the buffer loss while maintaining acceptable user delays. The minimum required buffer capacity and switch speed-up for each service in a prioritized environment are found under uniform traffic conditions. It is shown that under uniform traffic conditions, only minimal buffering and switch speed-up are needed even for the lowest priority users. The performance dependence on the switch size is also substantially reduced with head of line resolution and buffering even in a prioritized environment.
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 per...
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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