检索结果-内蒙古大学图书馆

Developing a prototype concurrent design tool for composite topside structures

NAVAL ENGINEERS JOURNAL 1997年第3期109卷 279-290页

作者： Dirlik, S Hambric, S Azarm, S Marquardt, M Hellman, A Bartlett, S Castelli, V Steve Dirlik:began his career at the Naval Surface Warfare Center Carderock Division in 1981 as an aerospace engineer co-op student. He completed his bachelor of science degree in aeropace and ocean engineering from Virginia Polytechnic Institute and State University in 1985 and his master of science degree in aerospace engineering from the University of Maryland in 1990. Mr. Dirlik recently completed a master of science program in applied physics at The Johns Hopins University and currently works in the Radar Cross Section and Target Physics Branch of the Signatures Directorate at the Naval Surface Warfare Center Corderoke Division. He has worked on Navy low observable programs since 1990. Stephen Hambric:is a research associate at the Applied Research Laboratory at The Pennsylvania State University. He received his B. S. and M.S. degree in mechanical engineering from Virginia Polytechnic Institute and State University and his D. Sc. in mechnical engineering from the George Washington University. He has worked on several computer aided multidiscikplinary design and optimization projects over the years including an automated propeller design system and a structural acoustic optimization capability. Dr. Shpour Azarm:is currently working as an associate professor with the Design and Manufacturing Group of the Department of Mechanical Engineering at the University of maryland at College Park. Dr Azarm's expertise is in the areas of optimization-based designed and concurrent design and optimization of multidisciplinary systems. He was a consultant at Black & Decker Corporation (summer 1996) and worked as a Navy senior summer faculty fellow (summer 1995) and a NASA summer faculty fellow (summer 1994). He was a visiting scientist at NASA Langley Research Center for Multidisciplinary Analysis and Applied Structural Optimzatiom at the University of Siegen in Germany (spring 1992) and the Design Institute of the Technical University of Denmark (summer 1990). Dr Azarm was an associate technical editor of the ASME Jour

A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.

关键词： Warships

来源：评论

学校读者我要写书评

暂无评论

Fast and accurate method to measure interharmonics in power systems

引用

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER 1996年第3期6卷 169-174页

作者： Dai, X Gretsch, R [?]Associate Prof. Dr.-Ing. Xianzhong Dai (1954) received the Dr. degree (Elec. Eng.) from Tsinghua University of China in 1986. In 1988 he joined Southeast University as Associate Professor. In 1991 he became Humboldt Research Fellow and worked for two years at University of Erlangen-Nurnberg/Germany. His research work is focused to real-time control measurement and computer application on reactive power and harmonics compensation in power systems. (Automatic Control Engineering Department Southeast University Nanjing Jiangsu P. R. China)

In order to improve the resolution of spectrum analysis, the traditional method is to take more sampling periods, e. g. 50 sampling periods corresponding to the spectrum interval of I Hz. This method is not suitable to the interharmonic measurement, because most interharmonics vary rather quickly with the time and so the analysis results based on long time sampling may be useless. In this paper the zero-padding technique with short sampling time is used to resolve interharmonics, and the zoom FFT is used to decrease the computation time in order to meet the needs of real-time measurement. The simulating computation shows that the resolution for two adjacent frequency components is usually sufficient to measure harmonics and interharmonics in power systems with acceptable short sampling and computation time. This method is also suited to analyse harmonics and interharmonics when there exists an undesirable asynchronous deviation between the sampling period and the signal period.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Hierarchical HAC/sub /spl infin///LAC vibration suppression for a flexible space telescope: SPICE

Hierarchical HAC/sub /spl infin///LAC vibration suppression ...

引用

American control Conference (ACC)

作者： A.A. Rodriguez D.R. Carter Department of Eiectrical Engineering Ceneter for System Science and Engineering Arizona State University Tempe AZ USA Mechanisms and Control Systems Honeywell Satellite Systems Glendale AZ USA GEM Doctoral Fellow in the Department of Electrical Engineering Arizona State University USA

This paper describes the synthesis of a dynamic compensator for a flexible space telescope described by a 280/sup th/ order finite-element NASTRAN-based model. The control objective is to attenuate the induced LOS jitter by a factor of 40 dB over the open loop value. A combination of low authority control (LAC) followed by high authority control (HAC/sub /spl infin//) which utilizes the H/sup /spl infin// optimal control methodology make up the hierarchical control system developed in this paper. The final design is shown to offer the required performance and robustness. The LAC loop is made up of two loops which provide broadband modal damping, modal spillover robustness, and actuator mode stabilization; all of which help in the design of the HAC/sub /spl infin//. The HAC/sub /spl infin// loop controller order is reduced from 130-states to 60-states by applying frequency-weighted balanced truncation techniques. The resulting hierarchical HAC/sub /spl infin///LAC controller is robustly stable against /spl plusmn/10% variation in actuator and sensor modeling.

关键词： Open loop systems Optimal control control systems Los Angeles Council Robustness Actuators Telescopes Finite element methods Jitter Damping

来源：评论

学校读者我要写书评

暂无评论

An approach to the direct analysis of transient stability

引用

European Transactions on Electrical Power 1993年第3期3卷 241-248页

作者： Djukanovic, M.B. Sobajic, D.J. Pao, Y.‐H. Miodrag B. Djukanovic (1959) received his B.S. M.Sc. and Ph.D. degrees in Electrical Engineering from the University of Belgrade/Yugoslavia in 1982 1985 and 1992 respectively specializing in electric power systems. In 1984 he joined the Electrical Engineering Institute “Nikola Tesla” in Belgrade where he was working on the scientific studies in the field of power systems planning operation and control. In 1985 and 1990 he was appointed as a research scholar at the Royal Institute of Technology Stockholm and Case Western Reserve University Cleveland Ohio. His major in- terests are in the area of power system analysis steady-state and dynamic security and application of neural networks in electric power systems. (Electrical Engineering Institute “Nicola Tesla” ul. Koste Glavinica 8A YU-11000 Belgrad T +3811/2351-619 Fax + 3811/2351-823) Dejan J. Sobajic (1949) received the B.S.E.E. and the M.S.E.E. degrees from the University of Belgrade/Yugoslavia in 1972 and 1976 respectively and the Ph.D. degree from Case Western Reserve University Cleveland Ohio in 1988. At present he is with the Department of Electrical Engineering and Applied Physics Case Western Reserve University Cleveland. He is also the Engineering Manager of A1 WARE Inc. Cleveland. His current research interests include power system operation and control neuralnet systems and adaptive control. He is a member of the IEEE Task Force on Neural-Network Applications in Power Systems and of the IEEE Intelligent Controls Committee. He is the Chairman of the International Neural-Networks Society Special Interest Group on Power Engineering. (Case Western Reserve University Department of Electrial Engineering and Computer Sciences Glennan Building Ohio 44 106 USA T + 1216/421-2380 Fax +1216/368-8776) Yoh-Han Pao (1922) has been a Professor of Electrical Engineering and Computer Science at Case Westem Reserve University (CWRU) Cleveland Ohio since 1967. He has served as chairman of the University's Electrical Engineering Department

The Transient Energy Function (TEF) method has been intensely investigated over the last decade as a reliable and accurate tool for transient stability assessment of multimachine power systems. In this paper we propose the Potential Energy Boundary Surface (PEBS) based method for direct analysis of transient stability. The critical value of transient energy and the Critical Clearing Time (T_CCT) are evaluated without the need for successive calculation and memorization of the system kinetic and potential energy values along the sustained fault trajectory. The method is used for determination of output features in the training phase of the neural‐net based transient security assessment. The proposed approach is tested on the well‐known ten‐generator New England test system demonstrating the validity and accuracy of obtained results. Copyright © 1993 John Wiley & Sons, Ltd.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Measurements of power and current components in unbalanced and distorted three‐phase systems

引用

European Transactions on Electrical Power 1993年第1期3卷 75-83页

作者： Andria, G. Salvatore, L. Savino, M. Trotta, A. Dr. Gregorio Andria (1956) AEI received the M. S. degree in Electrical Engineering from the State University of Bari/Italy in 1981 and the Ph. D. degree in Electrical Engineering in 1987 from the same University. From 1981 to 1983 he was working in the Electrotechnics and Electronics Department of the University of Bari as a member of the research team on electrical measurements. From 1984 to 1986 he was a Doctoral Fellow and currently he is a researcher in the same department. His research interests are in the fields of electrical and electronic measurements on components and systems including digital measurements for the analysis of electrical quantities in non-sinusoidal systems and the design of integrated optical sensors for measurement and control of non-electrical physical quantities. (Department of Electrotechnics and Electronics Faculty of Engineering polytechnic of Bovia E. Orabona 4 1-70125 Bari. Italy T +3980/242266 Fax + 3980/242410) Prof. Luigi Salvatore (1945) AEI received the degree in electrical engineering from the University of Bari/Italy in 1970. Since 1976 he has worked in the Electrotechnical and Electronic Department of the same University as a member of the research team on electrical machines. From 1983 to 1987 he was a researcher of electrical machines in the same department. Since 1987 he has been an Associate Professor of electrical machines at the University of Bari. At the present time his research interests include the control monitoring and diagnostics of AC drives and the areas of signal processing anddigital measurements on power electronics systems. (Department of Electrotechnics and Electronics Faculty of Engineering Polytechnic of Bari via E. Orabona 4 I-70125 Bari Italy T + 3980/242258 Fax + 3980/242410) Prof. Mario Savino (1947) AEI received the degree in Electrical Engineering from the University of Barif Italy in 1971. Since then he has been working in the Electrotechnical Institute of Bari until 1973 as researcher from 1973 to 1982 as Assistant Profe

The paper deals with the instantaneous power theory in three‐phase circuits by using the instantaneous time phasors of voltage and current. Particularly it is shown that the instantaneous components of the current time‐phasor in a rotating reference frame p‐q, oriented in such a way that the instantaneous voltage time‐phasor points to the p‐axis direction, represent the active and reactive currents. These components give rise to instantaneous real and imaginary powers, respectively. The spectral analysis of the above‐mentioned time‐phasors gives the harmonic symmetrical components of positive and negative sequence of voltage and current three‐phase systems. The line‐by‐line product of the voltage sequence spectrum by the complex conjugate of the current sequence spectrum gives the DC components of the instantaneous real and imaginary powers. The paper shows also that the instantaneous active and reactive currents are different from those defined on grounds of the Fryze's theory, which can be determined from the voltage and current sequence spectra. Copyright © 1993 John Wiley & Sons, Ltd.

关键词：

来源：评论

学校读者我要写书评

暂无评论

BANQUET ADDRESS - BUILT-IN COMBAT READINESS - APPROACH TO FUTURE SHIP DESIGN

引用

NAVAL ENGINEERS JOURNAL 1976年第3期88卷 40-43页

作者： MARCY, HT The Honorable H. Tyler (“Ty”) Marcy:was born in 1918 in Rochester New York but moved to Baltimore Maryland at an early age where he attended public schools. He is a graduate of the Massachusetts Institute of Technology from which he received both his BS and MS degrees in Electrical Engineering. Subsequent to receiving the latter degree in 1941 he designed and developed gun control systems in the MIT Servomechanism Laboratory until 1946 when he became Associate Director Special Projects Department M. W. Kellogg Company and worked on rocket engine development missile controls and analog air defense systems. In 1951 Mr. Marcy left Kellogg Company to join the IBM Corporation where he remained until 1972 and was employed in various engineering and managerial positions. At IBM his first assignment concerned the bomb/navigational system for the B-52 aircraft. He then moved into commercial development of data processing machines and peripheral devices subsequently being placed in a series of technical management positions which included Assistant Manager of Product Development Corporate Headquarters New York (1956) Manager Poughkeepsie N.Y. Laboratory (1957) Vice-President General Products Division (1962) Vice-President Systems Development Division (1965) and Director of Technology Corporate Headquarters Armonk N. Y. (1968). His last position was held until 1972 when he left IBM to do private consulting work in engineering management technology and program review. In October 1974 he was appointed by the President to his present office as Assistant Secretary of the Navy for Research and Development. Mr. Marcy has been a member of the Instrument Society of America since 1963 serving as its President from 1971 until 1974. In 1967 he became a Fellow of the Institute of Electrical and Electronic Engineers (IEEE) for his leadership in feedback control and for his significant contribution to the management of technical enterprise. In addition to these professional organizations he is also a member of the

来源：评论

学校读者我要写书评

暂无评论

Approximate Solution of a Class of Singular control Problems

引用

JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS 1974年第4期13卷 461-483页

作者： Vinter, R. B. Harkness Fellow Decision and Control Sciences Group Electronics Systems Laboratory Department of Electrical Engineering Massachusetts Institute of Technology Cambridge Massachusetts

A class of singular control problems involving amplitude constraints on the controls is examined. If L(infinity) is the space of control functions U, the control constraint set S can be identified with the unit ball in L(infinity). Now, for any n is an element of (1, infinity), an analogous problem may be set up with L(infinity) for U and the unit ball in L(n) for S. This modified problem is necessarily nonsingular for controllable systems. It is shown that, by taking n sufficiently large, the solution to the modified problem also solves the original problem arbitrarily closely (in a sense made precise). Behavior as n n -> infinity is investigated.

关键词： Duality theory linear systems nonlinear programming convex programming distributed control systems

来源：评论

学校读者我要写书评

暂无评论

Application of Duality Theory to a Class of Composite Cost control Problems

引用

JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS 1974年第4期13卷 436-460页

Let a control system be described by a continuous linear map L* from the input space U* (some dual Banach space) into the output space X* (some finite-dimensional normed space). Within the class of control problems where the constraints and cost are expressed in terms of the norms on the input and output spaces, the following two have had extensive coverage: (i) minimum effort problem: find, from amongst all inputs which have corresponding outputs lying in some closed sphere in X* centered on some desired output x(d)*, an output of minimum norm;and (ii) minimum deviation problem: find, from amongst all inputs lying in some closed sphere in U*, an input having corresponding output at a minimum distance from x(d)*. However, the composite cost problem, where we seek to minimize F(parallel to u*parallel to, parallel to x(d)* - x*parallel to) over elements satisfying x* = L*u* (F a certain kind of convex functional), has not received the same attention. This paper presents results for the composite cost problem paralleling known results for the minimum effort and deviation problems. It is hoped that a gap in the literature is thereby filled. We show that (a) a solution exists, (b) the solution can be characterized in terms of some closed hyperplane H in X, and (c) H can be computed as being an element on which some concave functional over closed hyperplanes in X achieves its maximum. The treatment allows of infinite-dimensional output spaces. We make extensive use of recently developed duality theory.

关键词： Singular problems linear systems convex programming suboptimal control

来源：评论

学校读者我要写书评

暂无评论

STUDIES OF A PLASMA PINCH SPACE ENGINE

引用

Journal of the American Society for Naval Engineers 1960年第4期72卷 715-725页

作者： GRANET, IRVING GUMAN, WILLIAM MCILROY, WILLIAM Irving Granet received his B.M.E. from The Cooper Union his M.M.E. from Polytechnic Institute of Brooklyn has taken Pre-Doctoral Studies at Polytechnic Institute of Brooklyn and is a graduate of the Oak Ridge School of Reactor Technology. He has worked in Republic's Plasma Propulsion Laboratory on nuclear propulsion systems space radiators thermodynamic power cycle considerations for generating electric power and system design and operation for space propulsion. He was formerly Director of Staff Engineering Nuclear Energy Department of Foster Wheeler Corporation where he directed engineering design and analysis for complete nuclear plants. Mr. Granet has taught thermodynamics and heat transfer at the Polytechnic Institute of Brooklyn and at present is Adjunct Assistant Professor of Engineering and Physics at Long Island University. He has published over 40 articles in the fields of thermodynamics applied mechanics heat transfer and nuclear energy. He is a member of the American Society of Mechanical Engineers National Society of Professional Engineers Pi Tau Sigma and Sigma Xi. He is a licensed Professional Engineer in the State of New York. Mr. Granet is listed in the 1960 edition of American Men of Science and is a reviewer for the American Chemical Society's technical publications. William J. Guman received degrees of B. Aero. E. M. Aero. E. from and has completed courses for Ph.D. Aero. E. at Rensselaer Polytechnic Institute. Since coming to Republic in 1959 Mr. Guman has been conducting theoretical and experimental studies on non-steady interactions and flow processes in plasma engine configurations. Mr. Guman was Assistant Professor at Rensselaer Polytechnic Institute lecturing on fluid mechanics aerodynamics performance and stability and conducting laboratory courses in experimental fluid dynamics and wind tunnel research. He also investigated flow induction and was head of Rensselaer's supersonic wind tunnel laboratory. Mr. Guman performed a theoretical analysis in experimental aerodynamic

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：