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HULL FORM DESIGN STUDIES FOR MONOHULL COMBATANTS

NAVAL ENGINEERS JOURNAL 1992年第1期104卷 28-35页

作者： WILSON, WB performed this work as a consultant between 1988 and 1990. He is currently employed with Exxon Production Research Company in Houston Texas. He has worked as a program manager at the National Data Buoy Center for NAVSEC and MarAd as a naval architect taught naval architecture at the Marine Institute (formerly College of Fisheries) in St. John's Newfoundland and served as principal ocean engineer for Computer Sciences Corporation. Mr. Wilson is a graduate of Webb Institute and holds a master's degree from M.I.T. the latter via the Society of Naval Architects and Marine Engineers Wilber N. Landers scholarship. He is a registered professional engineer in the State of Mississippi and a member of SNAME and ASNE.

In support of the power-limited design approach for monohull combatants, a series of hull form studies was undertaken with the objective of developing simplified algorithms for use in early design stage ship synthesis numerical models. Resistance, propulsion, and seakeeping performance were analyzed. Algorithms were generated for bare hull resistance, varying L/B and displacement with optimum prismatic, for the effect of bow and stern bulbs, and for the drag of appendages. Propulsion formulae were derived for twin screw conventional propulsion for large diameter, controllable-reversible pitch propellers, and counter-rotating propellers. For the specific case of the stern bulb hull, a single screw propulsive coefficient was determined. In the seakeeping area, equations were formulated to estimate secondary hull form parameters (given basic hull characteristics), for use in Bales equation for R, an established seakeeping measure of merit. Then, R was related to Operability Indices (OI) in various sea states and, thus, the overall Seakeeping Performance Index (SPI) for a specific "combat" set of motion criteria. The effects of fins and rudder roll stabilization were added. The result is an easy-to-use technique for determining seakeeping operability in early stage design. For the power-limited design approach, substantial benefits in propulsion and seakeeping can be obtained from a high L/B, optimum C(p), seakeeping hull form. Incorporation of a bow and stern bulb and single screw propulsor can further significantly improve powering with minimal impact on operability in a seaway.

关键词： Warships

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CAD CAM GOES TO SEA - THE SAAR-5 DESIGN AND CONSTRUCTION

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NAVAL ENGINEERS JOURNAL 1992年第3期104卷 148-155页

作者： LINDGREN, JR SOLITARIO, WA MOORE, AP STREIFF, MA John R. Lindgren Jr:. is vice president for engineering at Ingalls Shipbuilding Inc. a Division of Litton Industries in Pascagoula Miss. He joined Ingalls in 1958 and has held various positions in the Engineering Division and participated in the design of numerous merchant ships drill rigs submarines and surface combatants and auxiliary support ships. Mr. Lindgren is a 1958 graduate of the University of Southwest Louisiana. His degree is in mechanical engineering and he is also a licensed professional engineer. William A. Solitario:is the director of advanced technology at Ingalls Shipbuilding Inc. in Pascagoula Miss. He received his B.S. degree in chemical engineering from the City University of New York and has 28 years experience in marine engineering and design. His current responsibilities include the direction of Ingalls' IRAD programs and several Navy-funded R&D programs to improve ship's performance and reduce ship's operating costs. He is a member of the Society of Naval Architects and Marine Engineers and past chairman of the Gulf Section East Area. Arnold P. Moore:is the director design engineering at Ingalls Shipbuilding where he is responsible for all new construction design and engineering activities. Prior to promotion to his current position Mr. Moore served as chief naval architect at Ingalls. He has 24 years experience in ship design construction and repair. Mr. Moore holds the professional degree of ocean engineer as well as a master's degree in naval architecture and marine engineering from MIT. He also earned a bachelor's degree in naval science from the U.S. Naval Academy and is a registered professional engineer. Mr. Moore served as an engineering duty officer in the U.S. Navy and is currently a captain in the Naval Reserve. He is a past chairman of the Gulf Section of the Society of Naval Architects and Marine Engineers and a member of the American Society of Naval Engineers and Sigma Xi. Michel A. Streiff:is the manager of CAD/CAM applications at Ingalls Shipbuilding Inc. His

The SA'AR-5 Corvette program is the first major warship construction to be entirely accomplished using a 3-dimensional, interference checked computer based design. This paper discusses the organization and approach used to create the design models which form the basis for interference checking as well as the source of extracted production data. The design or product model is the nucleus of the computer data base that defines the configuration of the entire ship. The data base includes geometry, weight, and material, as well as production control data. The ability of the computer to link such diverse information is the key to maintaining configuration control during the course of the design and construction. The ease with which formatted manufacturing data (both N.C. fabrication and installation) can be extracted enables the preparation of detailed packages containing the desired geometry as well as the associated material and sequencing data, thus assuring the producibility of the design. The SA'AR-5 design is CAD/CAM's state of the art in U.S. shipbuilding.

关键词： Warships

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Fast approximation algorithms for multicommodity flow problems 91

Fast approximation algorithms for multicommodity flow proble...

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23rd Annual ACM Symposium on Theory of Computing, STOC 1991

作者： Leighton, Tom Makedont, Fillia Plotkin, Serge Steins, Clifford Tardost, Eva Tragoudas, Spyros Department of Mathematics and Laboratory for Computer Science MIT CambridgeMA United States Computer Science Program University of Texas at Dallas RichardsonTX75083 United States Deparment of Computer Science StanfordCA United States Laboratories Graduate Fellowship MIT CambridgeMA02139 United States School of Operations Research Cornell University IthacaNY United States Computer Science Program University of Texas at Dallas RichardsonTX75063 United States

ISBN: (纸本)0897913973

All previously known algorithms for solving the multicommodity flow problem with capacities are based on linear programming. The best of these algorithms [14] uses a fast matrix multiplication algorithm and takes O(k25n2m5 log(nDU)) time to find an approximate solution, where κ is the number of commodities, n and m denote the number of nodes and edges in the network, D is the largest demand, and U is the largest edge capacity. Substantially more time is needed to find an exact solution. As a consequence, even multicommodit y flow problems with jnst a few commodities are believed to be much harder than single-commodity maximum-flow or minimum-cost flow problems. In thk paper, we describe the first polynomial-Time combinatorial algorithms for approximately solving the multicommodity flow problem. The running time of our randomized algorithm is (up to ,log factors) the same as the time needed to solve κ single-commodity flow problems, thus giving the surprising result that approximately computing a κ-commodity maximum-flow is not much harder than computing about κ single-commodity maximum-flows in isolation. In fact, we prove that a (simple) κ-commodity flow problem can be approximately solved by approximately solving O(κ log2 n) single-commodity minimum-cost flow problems. Our κ-commodity algorithm runs in O(knm log4 n) time with high probability. We also describe a deterministic algorithm that uses an O(κ)-factor more time. Given any multicommodit y flow problem as input, both rdgorithms are guaranteed to provide a feasible solution to a modified fIOW problem in which all capacities are increased by a (1 + c)-factor, or to provide a proof that there is no feasible solution to the original problem. We also describe faster approximation algorithms for multicommodity flow problems with a special structure, such as those that arise in the 'sparsest cutn problems studied in [8, 10, 9], and the uniform concurrent flow problems studied in [13, 9] if κ ≥ √m. © 1991 ACM.

关键词： Approximation algorithms

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FIELD SAMPLING OF RESIDUAL AVIATION GASOLINE IN SANDY SOIL

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GROUND WATER MONITORING AND REMEDIATION 1991年第2期11卷 107-120页

作者： OSTENDORF, DW LEACH, LE HINLEIN, ES XIE, YF 1 David W. Ostendorf is an associate professor in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include unconfined aquifer contamination hazardous waste site remediation and analytical modeling of problems in environmental fluid mechanics. Dr. Ostendorf is a registered professional engineer in Massachusetts and a member of the American Geophysical Union American Society of Civil Engineers Soil Science Society of America Water Pollution Control Federation and Association of Environmental Engineering Professors as well as the National Water Well Association.2 Lowell E. Leach is an environmental engineer with the Robert S. Kerr Environmental Research Laboratory of the U.S. Environmental Protection Agency (RS Kerr Environmental Research Laboratory U.S. EPA P.O. Box 1198 Ada OK74820). Leach received his B.S. ingeological engineering at the University of Oklahoma in 1959 and has been a registered professional engineer in Oklahoma since 1966. With 29 years of experience in field applications of geological engineering he is responsible for developing methodology for sampling ground water and subsurface materials for the Robert S. Kerr Environmental Research Laboratory.3 Erich S. Hinlein is a research assistant in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include ground water pollution hazardous waste site investigation and transport processes in unconfined aquifers. Hinlein graduated with a B.S. in electrical and computer engineering from the University of Massachusetts at Amherst in May 1985 and entered the Environmental Engineering Master's Degree Program in January 1989.4 Yuefeng Xie is a postdoctoral research associate in the Environmental Engineering Program of the Civil E

Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint-size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. The barrel extrusion procedure involved jar headspace sampling in a nitrogen-filled glove box, which delineated the 0.7m thick residually contaminated interval for subsequent core sleeve withdrawal from adjacent boreholes. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half-pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions.

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FULL-WAVE SOLUTION OF DIELECTRIC LOADED WAVE-GUIDES AND SHIELDED MICROSTRIPS UTILIZING FINITE-DIFFERENCE AND THE CONJUGATE-GRADIENT METHOD

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INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE computer-AIDED ENGINEERING 1991年第4期1卷 346-357页

作者： NARAYANAN, V MANELA, M LADE, RK SARKAR, TK Department of Electrical and Computer Engineering Syracuse University Syracuse New York 13244-1240 Viswanathan Narayanan was born in Bangalore India on December 14 1965. He received the BE degree in Electronics and Communications from B.M.S. College of Engineering Bangalore in 1988. He joined the Department of Electrical Engineering at Syracuse University for his graduate studies in 1989 where he is currently a research assistant. His research interests are in microwave measurements numerical electromagnetics and signal processing. Biographies and photos are not available for M. Manela and R. K. Lade. Tapan K. Sarkar (Sf69-M'76-SM'X1) was born in Calcutta. India on August 2 1948. He received the BTech degree from the Indian Institute of Technology Kharagpur India in 1969 the MScE degree from the University of New Brunswick Fredericton Canada in 1971. and the MS and PhD degrees from Syracuse University. Syracuse NY in 1975. From 1975-1976 he was with the TACO Division of the General Instruments Corporation. He was with the Rochester Institute of Technology (Rochester NY) from 1976-1985. He was a Research Fellow at the Gordon Mckay Laboratory Harvard University Cambridge MA from 1977 to 1978. He is now a Professor in the Department of Electrical and Computer Engineering Syracuse University. His current research interests deal with numerical solutions of operator equations arising in electromagnetics and signal processing with application to system design. He obtained one of the “ best solution” awards in May 1977 at the Rome Air Development Center (RADC) Spectral Estimation Workshop. He has authored or coauthored more than 154 journal articles and conference papers and has written chapters in eight books. Dr. Sarkar is a registered professional engineer in the state of New York. He received the Best Paper Award of the IEEE Transactions on Electromagnetic Compatibility in 1979. He was an Associate Editor for feature articles of the lEEE Antennas arid Propagation Sociefy Newsletter and was

Dynamic analysis of waveguide structures containing dielectric and metal strips is presented. The analysis utilizes a finite difference frequency domain procedure to reduce the problem to a symmetric matrix eigenvalue problem. Since the matrix is also sparse, the eigenvalue problem can be solved quickly and efficiently using the conjugate gradient method resulting in considerable savings in computer storage and time. Comparison is made with the analytical solution for the loaded dielectric waveguide case. For the microstrip case, we get both waveguide modes and quasi-TEM modes. The quasi-TEM modes in the limit of zero frequency are checked with the static analysis which also uses finite difference. Some of the quasi-TEM modes are spurious. This article describes their origin and discusses how to eliminate them. Numerical results are presented to illustrate the principles.

关键词： Waveguides

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A course in professional responsibility for computer scientists 90

A course in professional responsibility for computer scienti...

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1990 Conference on computers and the Quality of Life, CQL 1990

作者： Friedman, Batya Interdisciplinary Computer Science Graduate Program Mills College 5000 MacArthur Blvd. OaklandCA94613 United States

ISBN: (纸本)0897914031

Within the computer science curriculum, the social and ethical aspects of computing can be partially addressed with a specialized course on these issues. This paper discusses one such course, briefly examining its strengths, specific goals, and implementation. A detailed course description is then provided that includes a syllabus and sample student assignments. © 1990 ACM.

关键词： Education computing

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Expert DB: an assistant database design system 90

Expert DB: an assistant database design system

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Proceedings of the 3rd international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1

作者： A. I. Concepcion R. M. Villafuerte Department of Computer Science Michigan State University Computer Science Graduate Program De La Salle University

ISBN: (纸本)9780897913720

This paper presents an assistant database design system, ExpertDB, which is based on entity-relationship (ER) approach. The approach is to synthesize a normalized ER schema (which consists of entity set and relationship set expressions) from functional dependencies (FD). Using as input the set of attributes and FD's, we derive the minimal cover of FD's, partition and regroup FD's, and finally form the entities and relationship sets. In every aspect of these derivations, ExpertDB provides assistance to the user, which is usually the database administrator (DBA), in the database design. The resulting ER schema is then mapped to relational schema.

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Real-time robot motion planning using rasterizing computer graphics hardware 90

Real-time robot motion planning using rasterizing computer g...

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Proceedings of the 17th annual conference on computer graphics and interactive techniques

作者： Jed Lengyel Mark Reichert Bruce R. Donald Donald P. Greenberg Graduate Student Program of Computer Graphics Cornell University Ithaca N.Y. Assistant Professor and Director Computer Science Robotics Laboratory Department of Computer Science 4130 Upson HalI Cornell University Ithaca N.Y. Director Program of Computer Graphics Jacob Gould Shurman Professor of Computer Graphics Cornell University Ithaca N.Y.

ISBN: (纸本)9780897913447

We present a real-time robot motion planner that is fast and complete to a resolution. The technique is guaranteed to find a path if one exists at the resolution, and all paths returned are safe. The planner can handle any polyhedral geometry of robot and obstacles, including disjoint and highly concave unions of *** planner uses standard graphics hardware to rasterize configuration space obstacles into a series of bitmap slices, and then uses dynamic programming to create a navigation function (a discrete vector-valued function) and to calculate paths in this rasterized space. The motion paths which the planner produces are minimal with respect to an L1 (Manhattan) distance metric that includes rotation as well as *** examples are shown illustrating the competence of the planner at generating planar rotational and translational plans for complex two and three dimensional robots. Dynamic motion sequences, including complicated and non-obvious backtracking solutions, can be executed in real time.

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PERTURBATIVE SOLUTIONS OF QUANTUM MECHANICAL PROBLEMS BY SYMBOLIC COMPUTATION: A REVIEW

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International Journal of Modern Physics C 1990年第1期1卷 53-76页

作者： T. C. SCOTT R. A. MOORE G. J. FEE M. B. MONAGAN G. LABAHN K. O. GEDDES Guelph-Waterloo Program for Graduate Work in Physics Waterloo Campus Canada Department of Computer Science University of Waterloo Waterloo Ontario N2L-3G1 Canada

It is shown that Symbolic Computation provides excellent tools for solving quantum mechanical problems by perturbation theory. The method presented herein solves for both the eigenfunctions and eigenenergies as power series in the order parameter where each coefficient of the perturbation series is obtained in closed form. The algorithms are expressed in the Maple symbolic computation system but can be implemented on other systems. This approach avoids the use of an infinite basis set and some of the complications of degenerate perturbation theory. It is general and can, in principle, be applied to many separable systems.

关键词： Symbolic computation Maple Quantum mechanics Perturbation theory

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Evaluation of classes of definite integrals involving elementary functions via differentiation of special functions

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Applicable Algebra in Engineering, Communication and Computing 1990年第2期1卷 149-165页

作者： Geddes, K.O. Glasser, M.L. Moore, R.A. Scott, T.C. Department of Computer Science University of Waterloo Waterloo N2L 3G1 Ontario Canada Department of Physics and Department of Mathematics and Computer Science Clarkson University Potsdam 13676 New York United States Guelph-Waterloo Program for Graduate Work in Physics Waterloo Campus United States the Institute for Theoretical Atomic and Molecular Physics at the Harvard-Smithsonian Center for Astrophysics Cambridge 02138 MA 60 Garden Street United States

Herein, it is shown that by exploiting integral definitions of well known special functions, through generalizations and differentiations, broad classes of definite integrals can be solved in closed form or in terms of special functions. This is especially useful when there is no closed form solution to the indefinite form of the integral. In this paper, three such classes of definite integrals are presented. Two of these classes incorporate and supercede all of Kölbig's integration formulae [11], including his formulation for the computation of Cauchy principal values. Also presented are the mathematical derivations that support the implementation of a third class which exploits the incomplete Gamma function. The resulting programs, based on pattern matching, differentiation, and occasionally limits, are very efficient. © 1990 Springer-Verlag.

关键词： Integration MAPLE Special Functions Symbolic Computation

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