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Bottom interaction measurements at FRAM II in the Pole Abyssal Plain of the Eastern Arctic Ocean

The Journal of the Acoustical Society of America 1981年第S1期69卷 S20-S20页

作者： Arthur B. Baggeroer Gregory L. Duckworth Departments of Ocean Engineering and Electrical Engineering and Computer Science M.I.T. Cambridge MA 02139 M.I.T./W.H.O.I Joint Program in Oceanographic Engineering Cambridge MA 02139

During the FRAM II experiment in the Pole Abyssal Plain of the Eastern Arctic Ocean, an extensive program of refraction shooting was conducted. Multichannel data on an 800 × 800 m hydrophone array and on an ocean bottom seismometer were obtained from shots deployed from a remote camp and by helicopter, at ranges up to 300 km. The multipath of the bottom interacting paths was resolved using high resolution velocity spectra. These spectra were used to determine (i) a crustal model for the seabed at the FRAM II site, (ii) the propagation loss and spreading for both the reflected and refracted bottom interacting paths, and (iii) conversion efficiencies of shear waves identifiable from the OBS. [Work supported by ONR.]

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MICROcomputer REALIZATIONS OF LYNN FAST DIGITAL-FILTERING DESIGNS

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MEDICAL & BIOLOGICAL engineering & COMPUTING 1980年第5期18卷 638-642页

作者： MALIK, NR Electrical & Computer Engineering Program University of Iowa Iowa City Iowa USA

The feasibility of real-time digital filtering using dedicated state-of-the-art microcomputers of 8-bit wordlength is demonstrated. Implementations of Lynn's integer filter structures by means of wrap-around queue data structures are shown to operate at sampling rates of over 8 kHz. An initial condition constraint unique to this filter class which must be satisfied to prevent inadvertent overflows or oscillations in microcomputers is discussed. The fast-filtering techniques are applied to the problem of calculating the average absolute value of a fast signal in real time.

关键词： Digital filters Microcomputers Online computing Signal processing

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THE LOGICAL RECORD ACCESS APPROACH TO DATABASE DESIGN

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COMPUTING SURVEYS 1980年第2期12卷 179-211页

作者： TEOREY, TJ FRY, JP Electrical and Computer Engineering CICE Program The University of Michigan Ann Arbor Michigan Database Systems Research Group Graduate School of Business Administration The University of Michigan Ann Arbor Michigan

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Prevention of task overruns in real-time non-preemptive multiprogramming systems

Prevention of task overruns in real-time non-preemptive mult...

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1980 International Symposium on computer Performance Modelling, Measurement and Evaluation, PERFORMANCE 1980

作者： Kim, K.H. Naghibzadeh, Mahmoud Computer Science Program University of South Florida TampaFL33620 United States Department of Electrical Engineering University of Southern California Los AngelesCA90007 United States

ISBN: (纸本)0897910192

Real-time multiprogramming systems, in which a hardware processor is dynamically assigned to run multiple software processes each designed to control an important device (user), are considered. Each software process executes a task in response to a service request repeatedly coming from the corresponding user. Each service task is associated with a strict deadline, and thus the design problem that we are concerned with is to ensure that the service tasks requested can always be executed within the associated deadlines, i.e., no task overrun occurs. This problem was studied by several investigators for the cases where preemptive scheduling strategies are used. In contrast, very few studies have been conducted for cases of non-preemptive scheduling. In this paper we show that a non-preemptive strategy, called relative urgency non-preemptive (RUNP) strategy, is optimal in the sense that if a system runs without a task overrun under any non-preemptive strategy, it will also run without a task overrun under the RUNP strategy. Then an efficient procedure used at the design time for detecting the possibility of a task overrun in a system using the RUNP strategy is presented. The procedure is useful in designing overrun-free real-time multiprogramming systems that yield high processor utilizations. Some special types of systems using the RUNP strategy for which even simpler detection procedures are available are also discussed. Index words: Real-time multiprogramming, task overrun, non-preemptive scheduling, time critical process, relative urgency. © Proceedings of the 1980 ACM Conference on LISP and Functional programming, LFP 1980. All rights reserved.

关键词： Scheduling

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JTIDS AIRBORNE ADAPTIVE ARRAY ANTENNA

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NAVAL ENGINEERS JOURNAL 1980年第3期92卷 119-128页

作者： COLEMAN, EW HEFFNER, WH Mr. Ernest W. Coleman is a Project Engineer in the Microwave Technology Branch Radar Division Sensors & Avionics Technology Directorate. of the Naval Air Development Center (NADC). Warminster. Pa. He began his professional career at NADC in 1971 after receiving his B.S. degree in Electrical Engineering from the Tennessee Technological University. He has held several engineering positions in the areas of Design. Development. Simulation and Test & Evaluation of both antenna systems and avionics systems. He did his graduate study in Electromagnetics at Ohio State University and has authored several technical papers and numerous reports. Currently. he is Project Engineer for the development of an Adaptive Array Antenna to be used with future communication systems such as JTIDS. Mr. W. Herbert Heffner Jr. is Head of the Microwave Technology Branch at NADC Wurminster. Pa. He received his B.S. degree in Electrical Engineering from Drexel University in 1962. and since then has held several design and development engineering positions at NADC and in the Naval Material Command. He attended Ohio State University during 1964 and 1965 receiving his M.S. degree in Electrical Engineering upon completion of his studies. For the past fourteen years he has been involved in the analysis. design development. and evaluation of aircraft antenna systems. radonies. and radar cross-section reduction techniques. In 1976. he was temporarily assigned as Program Element Administrator Surface and Aerospace Target Surveillance. under the Deputy Chief of Naval Material for Development. Naval Material Command. In his four years since returning to NADC. his responsibilities have included developing antennas for future Electronic Warfare and Communication Electronic Counter-Countermeasure applications as well as digital computer antenna analysis techniques and radar camouflage of tactical aircraft.

The Navy is developing an airborne adaptive array antenna for the Joint Tactical Information Distribution System (JTIDS). JTIDS is a Tri-Service multi-channel, multi-function system to provide an advanced communication, navigation, and identification (CNI) capability for a wide variety of uses. JTIDS terminals perform multiple digital voice/data functions and relative navigation as well as the standard TACAN and IFF transponder functions. The system uses a low-duty cycle, spread-spectrum waveform and advanced coding techniques to provide secure, jam-resistant, and low probability of exploitation CNI functions. Among the important factors which determine the ultimate utility of a JTIDS terminal is the performance of the antenna system. Inadequate antenna performance could seriously degrade and possibly even negate the primary platform mission. Recent advances in antenna and data processing techndogiea promise to provide JTIDS with adequate gain and pattern coverage as well as substantial AJ (Anti-Jam) margin to complement JTIDS signal processing. The desired improvement in AJ protection can be achieved by capitalizing on the spatial filtering properties of adaptive array antennas. This paper presents the “trade-offs” which must be addressed in the design of an adaptive array antenna for airborne JTIDS terminals and the design philosophy currently in development by the Navy.

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CENTML CONTROL SYSTEM TRAINING THROUGH STA TIC AND DYNAMIC SIMULATION

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Naval Engineers Journal 1980年第2期92卷 196-206页

作者： HALL, EDWIN E. MOSS, DONALD G. NORRIS, CLIFFORD S. PETERSON, HAROLD D. Mr. Edwin E. Hall received his Bachelor's degree in Electronics from Oklahoma City University. He also is a certified College-Level Instructor in the state of Florida and has done graduate work in Computer Science at the University of Florida. As the Technical Publications and Training Manager Simulation and Control Systems Department. General Electric Company Daytona Beach Fla. he currently is responsible for the costing. planning performance scheduling and timely completion of the Department's Technical Manuals and Technical Training Programs. These Training and Manual contracts cover Ship Systems Programs. Simulation Programs. and Communications Programs for the Armed Services and commercial customers. Mr. Hall has over twenty-years experience as a Technical Writer and Instructor and for the past seventeen years has been at the General Electric Company's Daytona Beach Facility. His experience ranges from teaching Basic Electronics and Radar Circuitry as a civilian instructor for the U.S. Army to writing Manuals Proposals Reports Specifications and Brochures for General Electric's product lines. Mr. Donald G. MOSS is a graduate of Kansas State University from which he received both his B.S. degree in Business Administration and his M.S. degree in Electrical Engineering. He is presently a Senior Systems Engineer for Control Systems in the Simulation and Control Systems Department at the General Electric Company's Daytona Beach Facility. He has been employed by General Electric for 23 years — the first seven as an Engineer and Program Manager on the Fire Control Systems for the Fleet Ballistics Missile Program the next six managing the design of control and checkout equipment on the APOLLO Program and the last ten years working on control equipment for the machinery plants of new Navy ships. Over the span of years at General Electric he has worked on propulsion control for the DD-963 propulsion electric plant and auxiliary control for the FFG-7: propulsion boiler burner electric auxiliary and car

Dynamic Simulation is defined as the hardware and software required to present to the student operator visual and audible cues and responses that are the same as those encountered when operating the Control Consoles aborad ship. This type of simulation is considered essential to the development of operator skills for critical tasks. Less critical tasks can be practiced using static simulation devices. This paper discusses the utilization of these types of training devices to train Navy crews. An overview of the Machinery Control Systems of the FFG 7 and AO 177 Class ships is discussed to provide an understanding of state‐of‐the‐art equipment development. The training programs for these two ship Classes are then reviewed to show how simulation devices are currently used by the Training Community, and this is followed by a brief discussion of the additional benefits that also are derived. © 1980 by the American Society of Naval Engineers, Inc.

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Time-Component Complexity of Two Approaches to Multioperand Binary Addition

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IEEE Transactions on computers 1979年第12期C-28卷 918-926页

作者： Atkins, Daniel E. Ong, Shau-Chi Program in Computer Information and Control Engineering the Systems Engineering Laboratory of the Department of Electrical and Computer Engineering University of Michigan Ann Arbor MI 48109 United States

Component and time complexity measures in terms of number of gates and gate delays, respectively, are derived for two multioperand adder structures: a tree of carry-save adders and a tree of carry-lookahead adders. The parameters of the complexity measures are operand length, number of operands, and maximum fanin to the gates. The analysis involves a constructive derivation of the complexity of carry-lookahead networks including optimization by removal of redundant paths. An alternate measure of component complexity, number of packages with a given number of pinouts, rather than number of gates, is also presented. The general conclusion of the paper is that, under the assumptions made, for a large set of design parameters, the carry-save adder structure requires both less time and fewer components than the functionally equivalent carry-lookahead adder structure. Copyright © 1979 by The Institute of electrical and Electronics Engineers, Inc.

关键词： binary addition carry-lookahead adder carry-save adder Index Terms-Adder tree multioperand addition time-component complexity

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Space-time tradeoffs for linear recursion 79

Space-time tradeoffs for linear recursion

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6th ACM SIGACT-SIGPLAN Symposium on Principles of programming Languages, POPL 1979

作者： Swamy, Sowmitri Savage, John E. Coordinated Science Laboratory Department of Electrical Engineering University of Illinois UrbanaIL61801 United States Program in Computer Science Division of Engineering Brown University ProvidenceRI02912 United States

ISBN: (纸本)9781450373579

A linear recursive procedure is one in which a procedural call can activate at most one other procedural call. When linear recursion cannot be replaced by iteration, it is usually implemented with a stack of size proportional to the depth of recursion. In this paper we analyze implementations of linear recursion which permit large reductions in storage space at the expense of a small increase in computation time. For example, if the depth of recursion is n, storage space can be reduced to √n at the cost of a constant factor increase in running time. The problem is treated by abstracting linear recursion into the pebbling of a simple graph and for this abstraction we exhibit the optimal space-time tradeoffs. © 1979 ACM.

关键词： Abstracting

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DESIGN, CONSTRUCTION, AND MODERNIZATION OF SHIPS WITH THE SHIPBOARD DATA MULTIPLEX SYSTEM (SDMS)

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NAVAL ENGINEERS JOURNAL 1979年第5期91卷 65-73页

作者： BOLD, NT BOURETTE, AP Dr. Norbert T. Bold graduated from Marquette University and later received his M.S. and Ph.D. degrees in Electrical Engineering from Northwestern University. He served three years as a Naval Engineering Officer aboard an Aircraft Carrier and a Minesweeper and has nineteen years technical experience in shipboard navigation underwater target and SDMS projects for the Navy. He is currently a Program Manager in the Autonetics Marine Systems Division Rockwell International where his primary assignment is the development of advanced concepts and applications of SDMS to Navy programs. He has published several technical papers. was elected to four Scholastic Honorary Societies and was the recipient of a NROTC Scholarship. Mr. A.P. Bourette Manager Systems Applications Autonetics Marine Systems Division. received his B.S. degree in Mathematical Physics from Long Beach State University. He began his career with a Computer Analysis Unit. performing tasks related to computer application. programming and interfacing. He has made significant contributions to the Central Computer Complex approach adopted for the SSN-688 Combat System and has performed inertial systems engineering efforts on the MK2 SINS for the POSEIDON Program. He spent some time in the Washington D.C. area providing technical expertise to various Navy organizations. Upon his return he soon was selected to manage the Systems Applications organization at Rockwell International. This organization is primarily responsible for the Shipboard Application of SDMS. He has directed several application studies showing the significant advantages associated with multiplexing. Recently. he provided the technical direction for the FY80 SSN SDMS Preliminary Design Phase.

Rockwell International is currently under Navy contract to fabricate the engineering Development Model (EDM) of the Shipboard Data Multiplex System (SDMS) for general data transfer aboard surface ships and submarines. The application of SDMS significantly reduces hardware such as cables, switchboards, and Signal Data Converters (SDC), and it provides the capability to add many desired features which are currently not practicable. In applying SDMS to a specific ship, a massive amount of signal data must be considered. The Application Design Automation program (ADAP) is a set of computer programs that have been developed to accomplish this task. ADAP com bines signal population data, ships configuration data, and SDMS hardware characteristics to produce an SDMS configuration layout together with documentation necessary to analyze, evaluate, and implement the system. Specific outputs include hardware requirements, system layout, and interface requirements including wire list information. The Timing, Event and Load Simulation (TELS) program simulates SDMS and provides performance data (system capacity, throughput rate, transport delays) for any system configuration. Conventional SDCs can be elimianted from Navy shipboard systems when SDMS is used. SDMS provides the necessary data distribution, signal conversion, and computer interface. In addition, many functions of the conventional switchboards can be performed within SDMS, thus reducing the size or eliminating conventional switchboards. Very small switch-bomb will provide the necessary control of data distribution. With SDMS, an automatic and continuous Noise and Vibration Monitoring (NVM) capability is readily available. The automated NVM function will enhance the safety, operation, and maintenance of the ship. Problems with machinery or excessive self-noise generation will be detected much sooner, and corrective action implemented on a timely basis.

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8th International Symposium on Multiple-Valued Logic, MVL 1978

作者： Atkins, D.E. Program in Computer Information and Control Engineering Systems Engineering Laboratory Department of Electrical and Computer Engineering University of Michigan Ann ArborMI48109 United States

An approach to the topic of computer arithmetic is suggested which may have a particular conceptual, pedagodical, and practical appeal to the designer of multiple-valued logic processors. computer arithmetic deals with the physical representation of finite sets of numbers and the design, analysis, and implementation of algorithms for mechanizing arithmetic operations on these sets. Finite number representation systems (FNRS) are specified by defining a set of symbols and a mapping from the elements of this symbol set to a subset of the real numbers. A formal definition of a FNRS provides a basis for a set of definitions which in turn provide the framework for the classification of a large set of number systems. Emphasis in this paper is on the following positive, fixed radix systems: unsigned, sign and magnitude, radix complement, and diminished radix complement. We offer an annotated listing of primitive digit vector algorithms for the four common number representation systems with an arbitrary, positive integer, fixed radix. These digit vector algorithms are ones which the designer of multi-valued logic arithmetic processors will need to implement to provide general arithmetic computation. © 1978 Advanced Automotive Batteries. All rights reserved.

关键词： Numbering systems

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