Renewed interest at EPRI on improved power flow techniques is due to the recent improvements in the robustness of fast power flow algorithms. In this paper the authors investigate two interacting parameters which affe...
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Renewed interest at EPRI on improved power flow techniques is due to the recent improvements in the robustness of fast power flow algorithms. In this paper the authors investigate two interacting parameters which affect convergence in power flow algorithms, limited precision and small impedance branches. Analytical methods and experimental results are given for predicting the minimum convergence tolerance achievable by an algorithm as a function of the infimum of the set of branch impedance values, and the number of bits of mantissa precision. Methods are suggested for increasing the virtual precision at minimal computational cost and for scanning power flow input data to determine whether available precision is sufficient.< >
作者：
TUCK, EFPATTERSON, DPSTUART, JRLAWRENCE, MHCalling Communications Corporation. 1900 West Garvey Ave
South. Suite 200 West Covina CA 91790 USA. Chairman of Calling Communications Corporation. He is also the Managing Director of Kinship Venture Management
Inc. the general partner of Kinship Partners 11 and a General Partner of Boundary the general partner of The Boundary Fund. As a venture capitalist he has founded or participated in founding several telecommunications companies including Calling Communications Corporation Magellan Systems Corporation
manufactures of Global Positioning System receivers Applied Digital Access
manufacturer of DS-3 test access and network performance monitoring equipment Endgate Technology Corporation
specialists in satellite phased array antennas and Poynting Systems Corporation. now a division of Reliance Corporation
manufacturers of fibre optic transport equipment. He was a founder of Kebby Microwave Corporation where he invented the first solid-state. frequency-modulated commercial microwave link system. The company was acquired by ITT Corporation where he rose to the position of V.P. and Technical Director of ITT North America Telecommunications Inc. Subsequently he was V.P. of Marketing and Engineering at American Telecommunications Inc. (ATC). He was founding Director of American Telecom Inc. a joint venture between ATC and Fujitsu and has served on more than 20 boards of directors including those of three public companies. He has authored articles on microwave engineering and telephone signalling and was a contributor to Reference Data For Radio Engineers. He is a graduate of the University of Missouri at Rolla where he was later awarded an honorary Professional degree and serves on its Academy of Electrical Engineering. Mr Tuck is a Senior Member of the IEEE a Fellow of the Institution of Engineers (Australia) a Professional Member of the AIAA and a registered professional engineer in three states. More than 25 years of experience in the telecommunications industry where he has been responsibl
There is a very large demand for basic telephone service in developing nations, and remote parts of industrialized nations, which cannot be met by conventional wireline and cellular systems. This is the world's la...
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There is a very large demand for basic telephone service in developing nations, and remote parts of industrialized nations, which cannot be met by conventional wireline and cellular systems. This is the world's largest unserved market. We describe a system which uses recent advances in active phased arrays, fast-packet switching technology, adaptive routeing, and light spacecraft technology, in part based on the work of the Jet Propulsion Laboratory and on recently-declassified work done on the Strategic Defense Initiative, to make it possible to address this market with a global telephone network based on a large low-Earth-orbit constellation of identical satellites. A telephone utility can use such a network to provide the same modern basic and enhanced telephone services offered by telephone utilities in the urban centres of fully-industrialized nations. Economies of scale permit capital and operating costs per subscriber low enough to provide a service to all subscribers, regardless of location, at prices comparable to the same services in urban areas of industrialized nations, while generating operating profits great enough to attract the capital needed for its construction. The bandwidth needed to support the capacity needed to gain these economies of scale requires that the system use K(alpha)-band frequencies. This choice of frequencies places unusual constraints on the network design, and in particular forces the use of a large number of satellites. Global demand for basic and enhanced telephone service is great enough to support at least three networks of the size described herein. The volume of advanced components, and services such as launch services, required to construct and replace these networks is sufficient to propel certain industries to market leadership positions in the early 21st Century.
Key issues regarding the operation of the broadband integrated services digital network (BISDN) via satellite are presented herein. The specific issues, challenges, and their resolutions are detailed. In particular, t...
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Key issues regarding the operation of the broadband integrated services digital network (BISDN) via satellite are presented herein. The specific issues, challenges, and their resolutions are detailed. In particular, the impact of error characteristics and propagation delay on the operation of BISDN via satellite is discussed. Solutions are presented for removing adverse effects and providing high-quality service to users of BISDN via satellite.
作者：
Fukuda, ToshioShimonaka, KenHosokai, HidemiDept
of Mechanical Engineering School of Engineering Nagoya University 1 Furocho Chikusa-ku Nagoya464 Japan Digital Switching System Enhancement Project
Software Engineering Center Nippon Telegraph and Telephone Corp NTT Shinagawa TWINS 1-9-1 Konan Minato-ku Tokyo108 Japan Dept
of Mechanical Engineering Science University of Tokyo 1-3 Kagurazaka Shinjuku-ku Tokyo162 Japan
The flexible functions of a human five finger hand with a palm were studied from the viewpoint of force sensory manipulation, unlike the conventional viewpoint of position based manipulation. It was clear that more th...
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The shipboard integrated machinery control system (SHIN-MACS) has been under development since 1977. It has moved from an idea, through a paper study, a wooden mock-up, a demonstrator console, to an advanced developme...
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The shipboard integrated machinery control system (SHIN-MACS) has been under development since 1977. It has moved from an idea, through a paper study, a wooden mock-up, a demonstrator console, to an advanced development model, and will first be operational in the Canadian patrol frigate (CPF) in 1988. The development of this integrated control system, particularly the latter part, has not been without its problems. However, through redesign and evaluation, the system is now real-time capable and should provide a marked improvement over traditional control systems, particularly in the area of operator interaction with the plant. The integrated machinery control system (IMCS) for the Canadian Patrol Frigate Program is the same design as the IMCS that is being retrofitted into the DDH-280 class of destroyers under the Tribal Class Update and Modernization Program (TRUMP). The IMCS is a microprocessor based distributed control system which provides automatic control and monitoring of the ship's machinery and systems. The system will have the most technologically advanced man-machine interface yet to be seen in a warship. The IMCS communicates with all of its components over a triple redundant data bus using redundant digital propulsion controllers. It also has an equipment health monitoring capability designed to assist in the reduction of life cycle cost of the machinery. The IMCS in the CPF has a significant growth potential. The IMCS is a software based system, and thus lends itself readily to modifications and adaptation to other vessels. This technology will impact on the operation of a modern warship by catering to reduced manning; it will also provide assistance in the implementation of on-condition based maintenance through the gathering of data electronically. The Canadian patrol frigate IMCS will be the first fully digital machinery control system to utilize data bus technology for all control and monitoring functions.
作者：
PAIGE, KKCONVERSE, RAUSNLCdr. Kathleen K. Paige
USN:graduated with a BA from the University of New Hampshire in 1970. She received her commission from Officer Candidate School in April 1971 and performed her first tour of duty with VFP-63 NAS Miramar. LCdr. Paige then received her MS from the Naval Post Graduate School in June 1976 and returned to San Diego to serve as Head Support Software Division at the Fleet Combat Direction System Support Activity. In May 1981 she reported to NA VSEA (PMS-408) where she served initially as Chairman of the NAVMAT Software Engineering Environment Working Group. She has been assigned as Deputy AN/UYK-43 Acquisition Manager since October 1981. LCdr. Paige was designated a fully qualified Engineering Duty Officer in December 1983. Robert A. Converse:is presently the Acquisition Manager for the Ada Language System/Navy (ALS/N) for the Naval Sea Systems Command Tactical Embedded Computer Resources Project. As such
he is responsible for the definition and development of the ALS/N to be provided as a Navy standard computer programming system for Navy mission critical applications. Mr. Converse received a Bachelor of Science degree in Physics from Wheaton College Wheaton II. He spent fourteen years with the Naval Underwater Systems Center Newport Rhode Island during which time he designed and developed the Fortran compiler for the Navy Standard AN/UYK-7 computer. Also during that period he received a Master of Science degree in Computer Science from the University of Rhode Island. His thesis for that degree was entitled “Optimization Techniques for the NUSC Fortran Cross-Compiler”. Mr. Converse started his involvement with the Ada program in 1975 with the initial “Strawman” requirements review. Subsequently he was named as the Navy Ada Distinguished Reviewer and was intimately involved in the selection and refinement of the Ada language as it evolved to become ANSI/MIL-STD-1815A.
The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of co...
The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of computer technology. Computers embedded in mission critical Navy systems are integral to our strategic and tactical defense capabilities. Thus, the military power of the U.S. Navy is inextricably tied to the use of programmable digital computers. The computer program is the essential element that embodies the system “intelligence”. In addition, it provides the flexibility to respond to changing threats and requirements. However, this very flexibility and capability poses a host of difficulties hindering full realization of the advantages. This paper describes the lessons learned about computer program development over the past twenty five years and discusses a softwareengineering process that addresses these lessons. It then describes how Ada and its related Ada Programming Support and Run-Time Environments foster this softwareengineering process to improve computer program productivity and achieve greater system reliability and adaptibility. Finally, the paper discusses how the use of Ada and its environments can enhance the interoperability and transferability of computer programs among Navy projects and significantly reduce overall life cycle costs for Navy mission critical computer programs.
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