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American Control Conference (ACC)

作者： B. Shafai L.H. Keel Department of Electrical and Computer Engineering Northeastern University Boston MA USA Center of Excellence in Information Systems Tennessee State University Nashville TN USA

A simple and direct pole placement algorithm is introduced for dynamical systems having a block companion matrix A. The algorithm utilizes well established properties of matrix polynomials. Pole placement is achieved by appropriately assigning coefficient matrices of the corresponding matrix polynomial. This involves only matrix additions and multiplications without requiring matrix inversion. A numerical example is given for the purpose of illustration.

关键词： State feedback Polynomials Matrices Differential equations Eigenvalues and eigenfunctions Closed loop systems Information systems Open loop systems Damping Control systems

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CAD CAM MANUFACTURING OF PROTOTYPE SHIPBOARD COMPONENTS

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NAVAL ENGINEERS JOURNAL 1990年第3期102卷 93-99页

作者： CALVERT, TE RODRIGUEZ, FA SLEBZAK, JS Thomas E. Calvert P.E.: is a senior project engineer with the Propulsion and Auxiliary Systems Department David Taylor Research Center Annapolis Md. His interests include application of computers to all aspects of engineering with particular emphasis on utilization of small computers. Mr. Calvert is a licensed professional engineer in Maryland. He received a BSEE from Drexel University in 1969 and since that time has completed a number of graduate courses related to machinery acoustics. Francisco A. Rodriguez:is an engineer with the Propulsion and Auxiliary Systems Department David Taylor Research Center. He was formerly with the Computer-Aided Design/Interactive Graphics Group of the Division of Engineering and Weapons U.S. Naval Academy. His interests include interfacing the computer aided design to the computer aided manufacturing along with related software and hardware development. Mr. Rodriguez received a BSEEfrom the University of Virginia in 1968. James S. Slebzak:is a mechanical engineering technician with the Propulsion and Auxiliary Systems Department David Taylor Research Center. He received his machinists papers in 1971 after serving his apprenticeship at David Taylor Research Center. He continued his education and became the senior numerical control programmer at the Annapolis Laboratory. He completed his mechanical technology degree from Anne Arundel Community College in 1986. His interests are in the application of numerically controlled manufacturing techniques to prototype machinery components.

The machine shop at the Annapolis Laboratory of the David Taylor Research center (DTRC) provides model making and prototype support to a large variety of naval ship related engineering projects. In order to meet these challenging requirements, computer aided design/computer aided manufacturing (CAD/CAM) techniques are being used to produce “one of a kind” prototypes or very low volume production parts. The use of computer aides in these cases is to facilitate the accurate manufacture of a difficult part, rather than to improve manufacturing efficiencies. In addition, the approach provides the flexibility required to support research and development projects. Several examples of prototype shipboard components manufactured using CAD/CAM techniques are presented in this paper. The hardware and software that facilitated these projects are discussed. The examples described have met the requirements to produce a wide variety of prototype shipboard machinery components quickly and accurately.

关键词： Ship Equipment

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COMPARATIVE STRUCTURAL LIFE ASSESSMENT OF PATROL BOAT BOTTOM PLATING

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NAVAL ENGINEERS JOURNAL 1990年第3期102卷 253-262页

作者： AYYUB, BM WHITE, GJ BELLWRIGHT, TF PURCELL, ES 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. He is engaged in research work involving structural reliability marine structures and mathematical modeling using the theories of probability statistics and fuzzy sets. His research work has been sponsored by the National Transportation Safety Board National Science Foundation U.S. Coast Guard Department of Defense State of Maryland and University of Maryland. He is the author of more than 100 publications in national and international journals conference proceedings and reports. Dr. Ayyub was a recipient of the ASNE “Jimmie” Hamilton Award for 1985 the ASCE “Outstanding Research Oriented Paper” in theJournal of Water Resources Planning and Managementfor 1987 and Edmund Friedman Young Engineer Award for Professional Achievement from ASCE for 1989. Gregory J. White:is an associate professor of naval architecture at the U.S. Naval Academy. He received his B.S. degreein 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 the author of more than two dozen technical articles and reports and is one of the U.S. representatives to the International Ship and Offshore Structures Congress (ISSC). His research interests lie in t

The estimation of an absolute life expectancy of a structure is a complex process and the results are expected to have relatively large levels of uncertainty. In this study, a comparative analysis is undertaken between two different patrol boats. This is an approach which results in a higher confidence level because certain factors common to both boats can be eliminated by assuming them to be at constant normal levels. The study is limited to the critical forward bottom plating and takes into account the differences in material, plate dimensions, operational profile, structure and loading of the two vessels. Two failure modes, plastic plate deformation and fatigue, are considered, and a novel approach to plate wastage is included. Many factors affect the structural life of a vessel. They include structural type, operational profile, structural details, loads, inspection and maintenance, design methods, safety factors, corrosion, and environmental factors. There are three types of uncertainty associated with these factors; namely, physical randomness, statistical uncertainties, and model uncertainties. The method described is designed to address these uncertainties. The objective of the paper is to present the reliability-based structural life assessment method, and then to use it to evaluate and compare the structural performance of the forward bottom plating of the two patrol boats. The results of the evaluation are presented in the form of graphs and tables in order to facilitate the comparative evaluation. The method is performed within a computer-based format which allows parametric sensitivity analysis of several variables including the size of the plating panel, thickness, operational profile and loading. The sensitivity of the structural life expectancy of the forward bottom plating to variations in these parameters is evaluated.

关键词： Naval Vessels

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Detection and characterization of flaws on machined metal surfaces 2

Detection and characterization of flaws on machined metal su...

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Optical Testing and Metrology II 1988

作者： Safabakhsh, Reza Gonzalez, Rafael C. Center of Excellence in Information Systems Tennessee State University NashvilleTN37209 United States Electrical and Computer Engineering Department University of Tennessee KnoxvilleTN37996 United States Perceptics Corporation Pellissippi Center KnoxvilleTN37922 United States

This work studies detection and characterization of flaws on machined metal surfaces based on the flaw depth. Diffracted light resulting from the incidence of a laser beam on the metal surface is sensed by a solid-state detector and analyzed by a digital computer to determine the surface conditions. Statistical analysis and pattern recognition algorithms are used to find data features which strongly correlate with the flaw depth. Trainable classifiers use these features to detect surface flaws whose (maximum) depth exceeds a given threshold. The range of flaw depth and a rough depth estimate are also determined and problems arising due to detector characteristics or interaction of flaw parameters are discussed. Experimental results of near 100% correct detection and 50% to 85% correct range determinations are reported. © 1989 SPIE. All rights reserved.

关键词： Digital computers

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Advanced symbolic and inference optical correlation filter results

Advanced symbolic and inference optical correlation filter r...

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Optical Pattern Recognition 1989

作者： Casasent, David Mahalanobis, Abhijit Fetterly, Donald Carnegie Mellon University Center for Excellence in Optical Data Processing Department of Electrical and Computer Engineering PittsburghPA15213 United States University of Arizona Electrical and Computer Engineering Department TucsonAZ85719 United States General Dynamics Valley Systems Division P.O. Box 50-800 ON91761-1085 Canada

New optical correlation filter results are reviewed for use in symbolic and inference correlators for ATR scene analysis. MACE filter synthesis has attractive properties that include: easily detectable peaks, distortion-invariance, simplified training set selection, solutions to input bias effects, performance in high noise, performance in real background clutter, region-of-interest MACE filters, filter quantization tests, and less clutter with its reduced number of training set images. © 1989 SPIE. All rights reserved.

关键词： Optical correlation

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Optical laboratory comparison of computer generated holograms for correlation matched spatial filters

Optical laboratory comparison of computer generated hologram...

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Digital and Optical Shape Representation and Pattern Recognition 1988

作者： Casasent, David Han, Chien-Wei Carnegie Mellon University Center for Excellence in Optical Data Processing Department of Electrical and Computer Engineering PittsburghPA15213 United States Optron Systems Inc. BedfordMA01730 United States

We consider various types of optical computer generated holograms (CGHs) using various encoding techniques. The application chosen is their use as optical matched spatial filters (MSFs) in an optical frequency plane correlator. This differs significantly from the use of CGHs for image reconstruction. Optical laboratory data is presented comparing the major types of CGHs on the same input data, using binary CGHs. The various issues associated with this use of CGHs are noted and quantified with optical laboratory data. © 1988 SPIE. All rights reserved.

关键词： Image reconstruction

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APPLICATION OF A GENERAL-PURPOSE CAD SYSTEM IN THE DDG-51 DESIGN PROCESS

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NAVAL ENGINEERS JOURNAL 1988年第3期100卷 265-274页

作者： AYERS, RE CALLAHAN, PJ KASSEL, B Randy E. Ayers:is a naval architect in the Computer Aided Engineering Division (Sea 507) of the Naval Sea Systems Command. He received his B.S.E. degree cum laude in structural materials and fluids engineering from the University of South Florida in 1979. Mr. Ayers began his career in the naval shipbuilding industry as a structural design engineer for the Long Beach Naval Shipyard. Currently he is the computer applications manager for the DDG-51 consultant for other ship design projects and has special responsibility for teaching CAD applications and utilization. He has received a letter of appreciation for his work on the DDG-51 ship design and has earned several superior achievement awards while involved in such projects as the battleship modernization and CIWS. Mr. Ayers has been a project leader for the LHA and FF-1052 class of ships and for a number of other ships undergoing construction. He is also an active member of ASNE. Patrick J. Callahan:is the manager of the Computer Aided Design Branch of the Computer Applications Directorate at Designers & Planners Inc. Mr. Callahan worked at General Dynamics Electric Boat Division for 10 years where he was involved in CAD detail design efforts for the SSBN-726 class and the SSN-688 class submarines. In 1984 he joined M. Rosenblatt & Son Inc. and was CAD design supervisor overseeing the operations of their CAD system. Currently managing the CAD Branch at D&P he is responsible for a variety of CAD projects such as being a key member of the DDG-51 Computer Aided Ship Design Program developing procedures and documentation for systems operation. He served as project manager for the IGES conversion of 650 FFG-7 class drawings from a McAuto to a Computervision database. Most recently he was responsible for generating the digital drawing package for the AO-177 (Jumbo) contract design. Ben Kassel:received his BSME from the University of Maine in 1981 and joined the David Taylor Research Center as a mechanical design engineer and later became the CAD/CAM system

This paper describes how the Naval Sea systems Command (NavSea) applied computer-aided design (CAD) to the DDG-51 class ship design. CAD tools and techniques are described along with a discussion on how new modes of operation, procedures, and standards are being introduced to take full advantage of CAD technology. Because geometric modeling techniques and geometric model analysis are major purposes of a CAD system they are described in detail. An explanation of how the model interfaces with other design tools is also presented. A summary of the computer applications implemented during the DDG-51 design is provided and areas which require additional consideration and future development are identified.

关键词： WARSHIPS

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THE EVOLUTION OF ROUND BILGE FAST ATTACK CRAFT HULL FORMS

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NAVAL ENGINEERS JOURNAL 1987年第6期99卷 52-62页

作者： TOBY, AS A. Steven Toby:received a B.A. degree in classical and near eastern archaeology from Haverford College in 1975. He then went to the University of Michigan where he received B.S.E. (1977) and M.S.E. (1979) degrees in naval architecture and marine engineering. From 1979 to 1981 he worked for the Center for Naval Analyses in Alexandria Virginia developing ship and submarine synthesis models. From 1981 to 1985 he worked for the Surface Ship Hydrodynamics Branch of the Naval Sea Systems Command (NavSea 55W32) where his duties involved ship powering and seakeeping predictions computer-aided lines development and cavitation erosion reduction (on hulls and appendages). This paper is the result of his work at NavSea in support of the PXM fast attack craft design. In 1986 he left NavSea to resume his education at Princeton University. He is a member of ASNE and SNAME.

THE AUTHOR 2 ABSTRACT When Yarrow mounted a torpedo tube on a steam launch in 1873 the fast attack craft (FAC) became a reality and a potent threat to warships of all sizes. Led by Great Britain, the major powers developed it into the destroyer, while minor powers continued the evolution of the torpedo boat. As early as 1915 the possibilities of the planing boat had been realized: the British Coastal Motor Boat (CMB), a 55-foot stepped hydroplane, could exceed 40 knots. But as military requirements required larger vessels, the limitations of planing craft, particularly in seakeeping although also in speed-power performance, led to a renaissance of the round bilge hull. Current round bilge designs trace their lineage back to the German “S-boats” of World War II. They predominate in size greater than about 250 tons. This paper discusses the historical evolution of the hull forms for high performance displacement warships. The paper covers innovations such as the transom stern and more subtle refinements such as changes in proportions and coefficients. For each change the historical background, the motivation for the change (both tactical and hydrodynamic), and operational experience with the new design contrasted with the old is presented. The focus will be on FACs, but material on early destroyers is included because of their important role in the evolution of the smaller craft. Today's round bilge FAC is a refined technology which has evolved over a long time. Now that it is being challenged strongly by the V-bottom form as well as by hydrofoils, air cushion vehicles, and surface effect ships, the designer must recognize how well a current round bilge design can perform. Accordingly, data is presented showing that today's round bilge hull form has improved dramatically in seakeeping, and is now competitive with the V-bottom.

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DEVELOPMENTS IN SWATH TECHNOLOGY

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NAVAL ENGINEERS JOURNAL 1986年第3期98卷 171-188页

作者： GUPTA, SK SCHMIDT, TW Sudhir “S.K.” Guptais currently manager technical programs at Lockheed Shipbuilding Company Seattle Washington. He graduated from the Marine Engineering College India in 1972 and spent eight years as a marine engineer on commercial ships including service as a licensed chief engineer. In 1981 he received his BSE degree in naval architecture and marine engineering from the University of Michigan. Before joining LSC Mr. Gupta worked with Designers and Planners Inc. His current responsibilities include management of SWA TH design and development efforts. Other experience has been in the fields of computer aided design and early-stage ship design. He received the Robert E. Gross Award for Technical Excellence as Engineer/Scientist of the Year from Lockheed Corporation in 1984 for his stability studies on LSD-41 class ships. Mr. Gupta has earlier presented technical papers on ship production and diesel engines. He is a member of SNAME ASNE RINA Institute of Marine Engineers and is registered as a chartered engineer in U.K. and in India. Terrence W. Schmidtgraduated from California State Polytechnic University in 1966 receiving his BS degree in aeronautical engineering. He received his MS degree in mechanical engineering from San Jose State University. Mr. Schmidt is currently a group leader at Lockheed Advanced Marine Systems Santa Clara previously known as the Ocean Systems Division of Lockheed Missile and Space Company. A key participant on all SWATH projects his work led to him being awarded the Robert E. Gross A ward for Technical Excellence as Engineer/Scientist of the Year in 198S. His responsibilities include hydrodynamic design development and analysis of SWATH ships. He has performed experimental and analytical studies on a variety of advanced marine vehicles. From 1966 to 1973 Mr. Schmidt worked at ARO Inc. as a project engineer responsible for planning conducting and documenting wind tunnel test programs. Models included missiles aircraft and marine vehicles.

It has been over two decades since the start of SWATH technology development began in earnest. SWATH is no longer an “emerging” technology. SWATH ships are now state of the art and the technology has come of age. With the construction of the 3500 ton Kaiyo in Japan, SWATH vessels have moved from prototypes and demonstrators to modern, high performance working vessels. A number of new design techniques have been developed which enhance the seakeeping and maneuvering capability of these ships. Other concepts currently being developed include producibility improvements, structural design manuals, cost and weight estimation standards, and performance predictions based on scale models. A synthesis computer program has been developed for conceptual design based on existing SWATH ships and designs.

关键词： SHIPS

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THE NO FRAME CONCEPT - ITS IMPACT ON SHIPYARD COST

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NAVAL ENGINEERS JOURNAL 1984年第3期96卷 218-232页

作者： NAPPI, NS WALZ, RW WIERNICKI, CJ Natale S. Nappi:graduated from City College of New York in 1954 with a B.S. degree in civil engineering and received his M.S. in civil engineering from the Polytechnic Institute of Brooklyn in 1959. He began his professional career in 1954 at the New York Naval Shipyard as a naval architect (structures) performing detail structural design and fabrication studies for CVAs LPDs DDs and CGs and eventually became a supervisory naval architect (structures). From 1965 to 1973 he was a member of the staff of the Computer-Aided Design Division at the David Taylor Naval Ship Research and Development Center (DTNSRDC). As such he was involved in the development of the computer structural design tool the SSDP (in association with Frank M. Lev) and automated detail design programs (CASDOS). His current position is Senior Naval Architect Consultant in the structural integrity group of the Ship Structures Division Structures Department DTNSRDC. Mr. Nappi is the author and co-author of numerous technical papers and reports covering a wide spectrum of topics such as automated structural design process design for producibility and survivability material weight and cost trade-off studies and structural weight determination for high performance ships (i.e. SES SWATH HYSWAS). He has lectured on the subjects of design for survivability and ship structures at the Naval Post Graduate School and MIT. He is a member of ASNE ASCE U.S. Naval Institute Sigma Xi and is a registered Professional Engineer in the State of New York. Mr. Nappi was a member of the NAVSEA working commitee for the computer supported design planning effort and is currently a member of the DTNSRDC ASSET Advisory Committee. Ronald W. Walz:graduated in 1974 from Pennsylvania State University with a B.S. degree in civil engineering. He began his professional career in 1974 at the David Taylor Naval Ship Research and Development Center as a structural engineer in the structural design concepts group of the Ship Structures Division Structures Department.

A proposed cost effective alternative to current U.S. Navy structurally configured hulls is presented in this paper. This proposed design for producibility concept involves the elimination of structural stanchions and transverse web frames. The potential impact of this “no frame” concept on structural design, weight and construction and material costs for naval surface frigates and destroyers is reflected in 1) reduced costs for the installation of distributive systems and 2) a reduced number and complexity of structural details providing a more reliable and less costly structure. This study was performed in three parts: 1) Determine the most feasible length between bulkheads without frames; 2) Using this length perform detail weight studies and construction and material costs analysis comparison on a 72-foot long hull module, with and without frames, for a FFG-7, and 3) Estimate the saving in man hours of labor on the installation of distributive systems and shipfitting for an FFG-7. For the feasible length studies on the “no frame” structural configuration, thirty-seven strength, weight and vertical center of gravity studies were performed on two ship classes; twenty-two on the FFG-7 class and fifteen on the DD-963 class. The detailed weight studies and construction and material cost analyses were conducted for FFG-7 “no frame” and “as built” modules. Results indicating the “no frame” concept module was 6.8% heavier and 14.8% less costly than the “as built” module. For the impact of an FFG-7 “no frame” structurally configured hull on the cost of labor required for the installation of distributive systems and for other functional work such as ship fitting, welding, and electrical, this study indicated a reduction of 169,206 labor hours per ship, representing 7.12% of the total required man hours to fabricate an FFG-7 class ship. With the employment of the “no frame” concept, certain areas of significant concern and potential risk were addressed. These include: 1) t

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