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IEEE Conference on Decision and Control

作者： D.L. Barnett G. de Saussure F.G. Pin A. Sabharwal S.S. Iyengar Center of Engineering Systems Advanced Research Oak Ridge National Laboratory Oak Ridge TN USA Oak Ridge Nat. Lab. TN USA Department of Computer Science Louisiana State University Baton Rouge LA USA

The core of the navigation program for the Oak Ridge CESAR (center for engineering systems advanced research) robots is a production system developed on the expert system shell CLIPS, which runs on an NCUBE hypercube aboard the robot. The production system can call on C-compiled navigation procedures. The production rules can read the sensor data and address the robot's effectors. This architecture was found to be efficient and flexible when used for the development and testing of the navigation algorithms. However, to process unexpected emergencies intelligently, it was necessary to control the production system through externally generated asynchronous data. This led to the design of an asynchronous production system, APS, which is being developed on the robot. Some of the navigation algorithms developed and tested at CESAR are reviewed, and the need for APS, and how it is being integrated into the robot architecture, are discussed.< >

关键词： Navigation Production systems Robot sensing systems Intelligent sensors Testing systems engineering and theory Expert systems Hypercubes Intelligent robots Control systems

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ESTIMATION OF STRUCTURAL SERVICE LIFE OF SHIPS

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NAVAL ENGINEERS JOURNAL 1989年第3期101卷 156-166页

作者： AYYUB, BM WHITE, GJ PURCELL, ES P.E. Bilal M. Ayyub:is currently an associate professor of civil engineering at the University of Maryland. He received his B.S. degree in civil engineering from the University of Kuwait in 1980. He completed both his M.S. (1981) and Ph.D. (1983) in civil engineering at the Georgia Institute of Technology. Dr. Ayyub has an extensive background in risk-based analysis and design simulation and construction engineering. He is engaged in research work involving structural reliability bridges marine structures and mathematical modeling using the theories of probability statistics and fuzzy sets. His research work is sponsored by the National Transportation Safety Board the National Science Foundation the U.S. Coast Guard the State of Maryland and the University of Maryland. Dr. Ayyub is a member of ASNE the American Society of Civil Engineers (ASCE) the American Concrete Institute (ACI) the Committee on Forensic Engineering of ASCE and the Committee on Structural Safety of ACI. He is the author of more than three dozen publications in national and international journals conference proceedings and reports. Dr. Ayyub received the ASNE “Jimmie” Hamilton Award for 1985 and the ASCE “Outstanding Research Oriented Paper” in the Journal of Water Resources Planning and Management for 1987. Gregory J. White:is an associate professor of naval architecture at the U.S. Naval Academy. He received his B.S. degree in engineering mechanics from Vanderbilt University in 1975 an M.E. degree in naval architecture from the University of California Berkeley in 1981 and a Ph.D. in civil engineering (structures) from the University of Maryland in 1986. Dr. White served on active duty with the U.S. Navy from 1975 to 1979 as a junior officer in the engineering and operations departments of Pacific Fleet destroyers. Prior to coming to the Naval Academy he worked at Mare Island Naval Shipyard in the scientific code and in the R&D division of Exxon International Company's Tanker Department. Dr. White is a lieutenant commande

A methodology for the structural life assessment of a ship's structure is suggested. The methodology is based on probabilistic analysis using reliability concepts and the statistics of extremes. In this approach, the estimation of structural life expectancy is based on selected failure modes. All possible failure modes of the ship must be investigated and the most likely paths to structural failure identified. For the purpose of illustration two failure modes are considered in this study. They are plate plastic deformation and fatigue cracking. Structural life based on these two failure modes is determined for an example vessel. The methodology determines the probability of failure of the ship's structural components according to the identified failure modes as a function of time. The results can be interpreted as the cumulative probability distribution function (CDF) of structural life. Due to the unknown level of statistical correlation between failure modes, limits or bounds on the CDF of the structural life are established. The limits correspond to the extreme cases of fully correlated and independent failure modes. The CDFs of structural life are determined for two inspection strategies; namely, inspection every year and inspection every two years with a warranty inspection at the end of the first year. The meaning of the results for the case investigated in this study is that, for example, given an inspection strategy of two years and a desired life of 15 years, there is a 72% chance that the vessel will not experience enough partial damage‘ in the failure modes identified to constitute reaching the “end of structural life” as defined.

关键词： Ships

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Boundary identification for 2-D parabolic problems arising in thermal testing of materials

Boundary identification for 2-D parabolic problems arising i...

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IEEE Conference on Decision and Control

作者： H.T. Banks F. Kojima Center of Control Sciences Division of Applied Mathematics Brown University Providence RI USA Institute of Computer Applications in Science and Engineering NASA-Langley Research Center Hampton VA USA

Problems on the identification of two-dimensional spatial domains arising in the detection and characterization of structural flaws in materials are considered. For a thermal diffusion system with external boundary input, observations of the temperature on the surface are used in an output least square approach. Parameter estimation techniques based on the method of mappings are discussed, and approximation schemes are developed based on a finite-element Galerkin approach. Theoretical convergence results for computational techniques are given, and the results are applied to the identification of two kinds of boundary shapes.< >

关键词： Materials testing Shape Composite materials Tomography Boundary conditions Thermal engineering mathematics computer applications NASA Temperature

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The visit problem: visibility graph-based solution

The visit problem: visibility graph-based solution

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IEEE International Conference on Robotics and Automation (ICRA)

作者： N.S.V. Rao S.S. Iyengar G. deSaussure Department of Computer Science Louisiana State University Baton Rouge LA USA Oak Ridge National Laboratory Center for Engineering Systems Advanced Research Oak Ridge TN USA

An algorithm to navigate a point robot through a sequence of destination points amid unknown stationary polygonal obstacles in a two-dimensional terrain is presented. The algorithm implements learning in the course of building a global terrain model by integrating the sensor information obtained during navigation. This global model is used in planning future navigational paths. This approach prevents the robot from making localized detours, and results in better navigation, in an average case, than obtained using algorithms without learning. The proposed algorithms are implemented in the C language on a simulator for a HERMIES-II robot running on an IBM PC.< >

关键词： Navigation Rain computer science systems engineering and theory Laboratories Sensor systems Heuristic algorithms Robot sensing systems Robotics and automation Automata

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Responses to “An Al view of the treatment of uncertainty” by Alessandro Saffiotti

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The Knowledge engineering Review 1988年第1期3卷 59-86页

作者： Clark, Dominic A. Prade, Henri Imperial Cancer Research Fund Laboratories London WC2A 3PX 44 Lincoln’s Inn Fields United Kingdom Engineering Mathematics Department University of Bristol United Kingdom NASA Ames Research Cenler/Heer Associates Inc. Mail slop: 244-17 Moffell Field CA 94040 United States Experimental Knowledge Systems Laboratory Department of Computer and Information Science University of Massachusetts Amherst Mass 01004 United States Laboratoire Langages et Systèmes Informatiques Université Paul Sabatier 118 route de Narbonne 31062 TOULOUSE Cédex France Imperial Cancer Research Fund Laboratories 44 Lincoln’s Inn Fields London WC2A 3PX United Kingdom Knowledge Systems Concepts Inc. Rome NY 13440 Italy MRC Biostatistics Unit Cambridge CB2 2BW United States IRIDIA Université Libre de Bruxelles 50 av. F. Roosevelt CP 194/6 1050 Bruxelles Belgium Computer Science Division University of California Berkeley CA 94720 United States

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HISTORY OF COAST-GUARD SURFACE EFFECT SHIP PERFORMANCE IMPROVEMENTS

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NAVAL ENGINEERS JOURNAL 1988年第3期100卷 237-250页

作者： LARIMER, G MCCOLLUM, J SCHAUB, B VANLIEW, D WHIPPLE, C Gary Larimer:received his B.S. (1974) and M.S. (1975) degrees in naval architecture and marine engineering from the University of Michigan. He has worked with the Bechtel Professional Corporation the David Taylor Naval Ship Research and Development Center and the United States Coast Guard. He is a member of SNAME ASNE ABYC and IMTI. He is the author of “Reaction Fin Applications In Marine Propulsion” which documented the use of asymmetric pre-swirl vanes to increase propulsion efficiency aboard a 41-ft Coast Guard utility boat. It was presented on 5 March 1987 at the Hampton Roads section of SNAME and was nominated for the section paper of the year award. CWO3 Joe Bobby McCollum USCG: iscurrently engineering officer of the Surface Effect Ship Division Seventh Coast Guard District Key West Florida. Prior to this assignment he was assistant engineering officer on the USCGCUte.His other duty tours included engineering assignments on theCape Currenta 95-foot patrol boat on the USCGCUnimak a 311-foot cutter CG Loran Station Upolo Point Hawaii and CG Station Sabine Pass Texas. CWO McCollum was responsible for modifying and repairing the SESs and contributed many unique problem solving ideas which resulted in much improved operation of the Coast Guard Surface Effect Ship Division. Benton H. Schaub:is a senior engineer with Maritime Dynamics Inc. He has a bachelor of science degree in naval architecture and marine engineering from the Massachusetts Institute of Technology. Mr. Schaub has fifteen years of experience working as a test engineer project engineer and design engineer on advanced marine vehicle projects and is a recognized authority in the areas of hull structure seal system and machinery design for surface effect ships. He has participated in virtually every USN SES design development and test evaluation program including: XR-5 XR-10 SES-100A SES-100A1 and the SES-200. He is currently responsible for performing detailed design and analysis in support of the seal system for the Germa

During the early 1980s the United States Coast Guard took delivery of three surface effect ships (SES) from Bell Halter, Inc. These 136-ton, 30-knot plus, aluminum hulled cutters were to be used primarily for drug interdiction in the southeastern United States. By early 1985, however, the full load weight of these cutters had grown to 150 long tons, and their top speed had dropped to below 23 knots in calm water. By mid-1985, operation of all three SESs was suspended to prevent possible catastrophic failure of their main engines. At this point, the USCG joined ranks with Textron Marine systems (then Bell Aerospace), and Detroit Diesel to analyze what had gone wrong, and to propose solutions to the problems encountered. From that beginning, the performance of the Coast Guard's SESs has steadily and dramatically improved until at present all three cutters are able to exceed their original performance specifications. This paper discusses the problems experienced with the SESs, including engine overloading, vibration, ride quality, seal wear, poor lift system performance, and metal cracking, along with the corrective actions taken to solve them. The cooperation between government and private industry, which made this dramatic turn-around in performance possible, is also explored. Lessons learned about SES technology are viewed in relation to the general experience of the Coast Guard with other types of high performance hull forms.

关键词： NAVAL VESSELS

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On terrain acquisition by a finite-sized mobile robot in plane

On terrain acquisition by a finite-sized mobile robot in pla...

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IEEE International Conference on Robotics and Automation (ICRA)

作者： N. Rao S. Iyengar C. Jorgensen C. Weisbin Department of Computer Science Louisiana State University Baton Rouge LA Engineering Physics and Mathematics division Center for Engineering Systems Advanced Research Oak Ridge National Laboratory Oak Ridge TN

The terrain acquisition problem deals with the acquisition of the complete obstacle terrain model by a mobile robot placed in an unexplored terrain. This is a precursory problem to many well-known find-path and related problems which assume the availability of the complete terrain model. In this paper, we present a method for terrain acquisition by a finite-sized robot operating in plane populated by an unknown (but, finite) number of polygonal obstacles; each obstacle is arbitrarily located and has unknown (but, finite) number of vertices. The robot progressively explores newer vertices of the obstacles using sensor equipment. We show that the complete terrain model will be built by the robot in a finite time. We also show that at any point of time the partially acquired terrain suffices for the navigation of the robot during the exploration. Hence we conclude that the navigation techniques for known terrains can be applied for the robot navigation during exploration.

关键词： Mobile robots Robot sensing systems Navigation Rain Power engineering and energy systems engineering and theory computer science Motion planning Shape Contracts

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Opinion

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The Mathematical Intelligencer 1987年第4期9卷 52-63页

作者： Karp, Richard Browder, William Chandra, Jagdish Hirsch, Morris Karp, Richard Melcher, James Shub, Michael Williams, Robert Axler, Sheldon University of California Berkeley United States Department of Mathematics Princeton University Princeton 08544 NJ United States Mathematics Division U.S. Army Research Office Research Triangle Park 27709 NC United States Department of Mathematics University of California Berkeley 94720 CA United States Department of Computer Science University of California Berkeley 94720 CA United States Department of Electrical Engineering and Computer Science MIT Cambridge 02139 MA United States Thomas J. Watson Research Center IBM Yorktown Heights 10598 NY United States Department of Mathematics Northwestern University Evanston 60201 IL United States Department of Mathematics Michigan State University East Lansing 48824 MI United States

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THE ROLE OF PERFORMANCE ANALYSIS IN THE LIFE-CYCLE OF A WEAPONS SYSTEM

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NAVAL ENGINEERS JOURNAL 1987年第3期99卷 239-248页

作者： BAILEY, JL The authoris an operations research analyst in the Systems Engineering Branch Aegis Ship Combat Systems Division at the Naval Surface Weapons Center (NSWC). Dr. Bailey received a B. S. degree in mathematics from the Massachusetts Institute of Technology in 1964 a Ph.D. in mathematics from the University of Tennessee in 1968 and an M. S. in computer science from the Virginia Polytechnic Institute and State University in 1975. He was an assistant professor of mathematics at the University of Tennessee during the 1968-69 academic year then came to NSWC/Dahlgren in September 1969. He worked as an operations research analyst in mine warfare from 1969 to 1978 specializing in minefield planning. He headed the group which developed the minefield planning module of the Mine Warfare Trainer which was delivered to the Fleet and Mine Warfare Training Center in 1978-79. Dr. Bailey served as science advisor to the commander Mine Warfare Command in 1978-79 under the sponsorship of the Navy Science Assistance Program. In 1979-80 he led the development of military value assessment methodology for a ship survivability improvement program. In 1980 he moved to the Aegis Ship Combat Systems Division becoming leader of the Systems Performance Assessment Group in 1981. Dr. Bailey leads a group of analysts who do assessment of the predicted performance of the Aegis combat system and the effects of proposed changes to the system. Dr. Bailey has also served collateral duty as systems analysis manager for the Technical Division of the Aegis Project Office (PMS-400) in the Naval Sea Systems Command since 1981.

Performance analysis is the process of determining the predicted performance of a weapons system. It is generally used to examine predicted performance of systems in a variety of configurations and operational situations; it is accomplished through a variety of techniques, from the computation of straightforward algebraic functions to complex computer simulations. Performance analysis is necessary throughout the life-cycle of weapons systems. It is used to help determine original requirements, for conceptual and detailed design, and to support operational planning and determine upgrade requirements. The development, maintenance, and consistent application of a set of system specific performance analysis methods have enhanced the development of many weapons systems. This paper is in the form of a tutorial on the application of performance analysis techniques, using the development of the Aegis weapons system as a source of examples, and stressing the value of performance analysis methods which have been designed specifically for the Aegis system.

关键词： MILITARY EQUIPMENT

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POTENTIAL NAVAL SHIPBOARD APPLICATION OF NONAZEOTROPIC ENERGY-CONVERSION

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NAVAL ENGINEERS JOURNAL 1987年第6期99卷 39-51页

作者： WU, C HWANG, BCC Dr. Chih Wu received his Ph.D. in mechanical engineering from the University of Illinois in January 1966. Presently he is a full professor in the Department of Mechanical Engineering at the U.S. Naval Academy. Since 1966 he has had more than 250 articles and papers presented at professional meetings and published in various journals and technical magazines concerning the subjects of energy thermodynamics heat transfer fluid dynamics computer science and education. Dr. Baochuan Hwang is a research specialist with the David Taylor Naval Ship R&D Center in Annapolis Maryland. He is responsible for the research activities in the Power Systems Division of the Propulsion and Auxiliary Systems Department at the Annapolis Laboratory. Prior to his employment with the Navy Dr. Hwang worked in industry at the General Electric Corporate R&D Center and at Aerochem Research laboratory. Dr. Hwang has worked extensively in the areas of machinery thermal systems rocket propulsion and heat transfer. His current interest is in the area of unsteady 3-D internal flows especially related to acoustic flow relationships in small rotating machinery.

The thermodynamic performance of an energy conversion device may be improved potentially by using a nonazeotropic mixture in a vapor cycle. A nonazeotropic mixture has a temperature distribution parallel to that of the surrounding fluid with which heat transfer takes place during the evaporation and condensation processes. Interest has increased in recent years in the use of nonazeotropic refrigerant mixtures to improve the performance of energy conversion devices. This report surveys developments in nonazeotropic energy conversion, describes the theory of a nonazeotropic energy conversion cycle, predicts energy savings possible from use of nonazeotropic energy conversion devices, and discusses potential naval shipboard application of such an energy conversion cycle.

关键词： Refrigerants

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