检索结果-内蒙古大学图书馆

PERFORMANCE OF A PRIORITIZED ON-BOARD BASEBAND SWITCH FOR A MULTISERVICE MULTIBEAM SATELLITE

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 283-297页

作者： BOHM, S ELHAKEEM, AK HACHICHA, M Department of Electrical and Computer Engineering Concordia University 1455 De Maisonneuve Blvd. West Montreal H3A 1M8 Canada Was born in Montreal Canada on 14 September 1966. He received the B. Eng. degree in electrical engineering from Concordia University Montreal Canada in 1989. He is at present completing the M.A.Sc. degree in electrical engineering at Concordia University. (S'75–S'79–M'79–SM'86) received the Ph.D. degree from Southern Methodist University Dallas TX in 1979. He spent the next two years working as a Visiting Professor in Egypt after which he moved to Ottawa Canada in 1982. He assumed teaching and research positions in Carleton and Manitoba Univerities and later moved to Concordia University Montreal Canada in 1983 where he is now a Professor in the Electrical and Computer Engineering Department. He has published numerous papers in IEEE and international journals in the areas of spread spectrum and networking. He is a well-known expert in these areas and serves as a consultant to many companies. His current research interests include wide-band metropolitan networks switching architectures and performance of on-board multibeam satellites acquisitionless CDMA networks code distribution and orthogonalization of CDMA signals responsive congestion control for ATM-based networks ARQ techniques and investigation of the novel SUGAR CDMA systems in fading channels. Dr. Elhakeem is a Senior Member of the Canadian Electrical Engineering Society and Armed Forces Association. He has chaired numerous technical sessions in IEEE Conferences was the Technical Program Chairman for IEEE Montech 1986 Montreal Canada. Dr. Elhakeem is the key guest editor of theIEEE Journal of Selected Areas in Communicationsfor the May June issues 1993 covering CDMA networks. Advanced Technology & Networks VISTAR Telecommunications Inc. Ottawa Ontario K1G 3J4 Canada An Associate Director of Advanced Technology & Networks Group VISTAR Telecommunications Inc. Ottawa Canada. He is also an Adjunct Pr

In this paper, we study the performance of a prioritized on-board baseband switch in conjunction with a multibeam satellite handling integrated services. The services considered for the analysis include voice, video, file transfer and interactive data. The prioritized switch uses both input and output buffering, switch speed-up as well as a two-phase head-of-line resolution algorithm, in order to reduce the buffer loss while maintaining acceptable user delays. The minimum required buffer capacity and switch speed-up for each service in a prioritized environment are found under uniform traffic conditions. It is shown that under uniform traffic conditions, only minimal buffering and switch speed-up are needed even for the lowest priority users. The performance dependence on the switch size is also substantially reduced with head of line resolution and buffering even in a prioritized environment.

关键词： SWITCH ON-BOARD BASEBAND MULTIBEAM PRIORITIZED HEAD-OF-LINE UNIFORM LOAD SPEED-UP

来源：评论

学校读者我要写书评

暂无评论

A Practical Adaptive Tracking Filter for Maneuvering Targets

引用

IFAC Proceedings Volumes 1993年第2期26卷 793-796页

作者： T.K. Sung J.G. Lee Department of Control and Instrumentation Engineering & Automation and Systems Research Institute Seoul National University Korea

A practical adaptive tracking filter for maneuvering targets and nonlinear measurements is proposed by combining a modified input estimation technique with pseudo-residuals and a decoupled tracking filter in LOS Cartesian coordinate system. Since the proposed adaptive tracking filter has a decoupled structure, maneuver input estimates can be computed for three axes separately. Consequently, without degrading performance, computation is drastically reduced compared to a coupled adaptive tracking filter with input estimation technique in inertial coordinate system. Also, by small cross-correlations of pseudo-measurement noises, the proposed tracking filter produces less false alarms or miss detections to improve the performance

关键词： adaptive tracking filter maneuvering targets decoupled tracking filter in line-of-sight coordinate system input estimation technique

来源：评论

学校读者我要写书评

暂无评论

Analysis and control of Interconnected Discrete System Using Robust Stability Condition

引用

IFAC Proceedings Volumes 1993年第2期26卷 307-310页

作者： H.S. Han J.G. Lee Department of Control and Instrumentation Engineering and Automation and Systems Research Institute Seoul National University Seoul Korea

This paper presents sufficient conditions for the stability of interconnected discrete systems and interconnected uncertain discrete systems. The stability conditions are developed by employing the property of spectral radius. It is shown that the stability conditions can be used in designing controllers for interconnected uncertain discrete systems. Specifically, using the proposed condition yields a new robust control design method for interconnected uncertain discrete system. A controller designed by the proposed method is demonstrated for a sample system. The proposed method significantly simplifies a robust controller design for interconnected systems.

关键词： Discrete system interconnected uncertain system stability sufficient condition local controller

来源：评论

学校读者我要写书评

暂无评论

Path constrained time-optimal motion of a cooperative two robot system

Path constrained time-optimal motion of a cooperative two ro...

引用

International Conference on Industrial Electronics, control and Instrumentation

作者： H.K. Cho B.H. Lee Department of Control and Instrumentation Engineering Automation and Systems Research Institute Seoul National University Seoul South Korea

This paper presents a systematic approach to the time-optimal motion planning of a cooperative two robot system along a prescribed path. First, the minimum-time motion planning problem is formulated in a concise form by parameterizing the dynamics of the robot system through a single variable describing the path. The constraints imposed on the input actuator torques and the exerted forces on the object are then converted into those on that variable, which result in the so-called admissible region in the phase plane of the variable. Considering the load distribution problem that is also involved in the motion, we present a systematic method to construct the admissible region by employing the orthogonal projection technique and the theory of multiple objective optimization. Especially, the effects of viscous damping and state-dependent actuator bounds are incorporated into the problem formulation so that the case where the admissible region is not simply connected can be investigated in detail. The resultant time-optimal solution specifies not only the velocity profile, but also the force assigned to each robot at each instant.< >

关键词： Robotics and automation Motion planning Actuators Robot sensing systems Path planning Multirobot systems Drives Acceleration Automatic control control systems

来源：评论

学校读者我要写书评

暂无评论

Fuzzy rule base derivation using neural network-based fuzzy logic controller by self-learning

Fuzzy rule base derivation using neural network-based fuzzy ...

引用

International Conference on Industrial Electronics, control and Instrumentation

作者： K.H. Kyung B.H. Lee Department of Control and Instrumentation Engineering Automation and Systems Research Institute Seoul National University Seoul South Korea

This paper presents a new rule base derivation method using neural networks for fuzzy logic control of dynamic systems. The proposed method needs neither dynamic models of the system nor control experts for the control problem. Multi-layered perceptron neural networks are used to form the neural network based quasi-fuzzy logic controller (QFLC). The control performance of the QFLC is achieved on-line using the feedback error learning scheme. The fuzzy control rules are then extracted from the input-output characteristics of the QFLC. They are reduced to form the fuzzy control rule base for an FLC through consecutive procedures such as smoothing, logical reduction, and test running and selection of firing rules. To verify the validity of the proposed rule base derivation method, the authors apply the method to fuzzy logic control of an inverted pendulum.< >

关键词： Fuzzy logic Fuzzy neural networks Neural networks Multi-layer neural network Fuzzy control control systems control system synthesis Multilayer perceptrons Neurofeedback Error correction

来源：评论

学校读者我要写书评

暂无评论

Initial results of an in-flight investigation of longitudinal flying qualities for augmented, large transports in approach and landing

Initial results of an in-flight investigation of longitudina...

引用

Guidance, Navigation and control Conference, 1993

作者： Rossitto, Ken F. Hodgkinson, John Williams, Todd M. Leggett, Dave B. Bailey, Randall E. Ohmit, Eric E. Stability Control and Flying Qualities Technology McDonnell Douglas Aerospace Transport Aircraft Long BeachCA United States Flight Control Systems Technology McDonnell Douglas Aerospace Transport Aircraft Long BeachCA United States Flying Qualities Group Control Dynamics Branch WL/FIGC United States Air Force Wright-Patterson AFB OH United States Flight Research Department Arvin/Calspan Advanced Technology Center BuffaloNY United States

Initial results of a piloted, in-flight simulator experiment using the USAF Total In-Flight Simulator (TIFS) are presented. Configurations with various levels of short period frequency acceleration sensitivity and equivalent time delay were flown and evaluated by a number of pilots. The pilot ratings were used to appraise the performance of the control anticipation parameter (CAP) criterion using the equivalent system methodology. The results indicated that for large transports the Category C Level 1 CAP lower boundary could be raised slightly, and that delays up to 250 msec do not noticeably degrade pilot opinion in simulated touchdowns. © 1993 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Flight simulators

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

Short‐term load forecast by plausibility checking of announced demand: An expert‐system approach

引用

European Transactions on Electrical Power 1993年第5期3卷 353-358页

作者： Markovié, M.L. Fraissler, W.F. Milorad L. Marković (1960) received the Dipl.-Ing. and M.Sc. degrees in electrical engineering from the University of Beognd in 1984 and 1990 respectively. From 1985 to 1991 he was at the Institute “Mihajlo Pupin” Beo-grad up to 1987 in the Operation Research group afterwards in the Power System group. In 1990/91 he spent a year at the Austrian Electricity Board (Verbundgesellschaft VG) in Vienna/Austria on a pilot project for expert-system application for operation scheduling. Since September 1991 he is a staff member of the central dispatching department of the VG. His research interests are application of the operations research methods and expert systems in power system control and operation. (Öster-reichische Elektrizitätswirtschafts-AG (Verbundgesellschaft) Hauptlastverteiler Am Hof 6a A-1010 Wien/Austria T +431/531 13 - 23 68 Fax +431/531 13 - 23 16) Walter F. Fraissler (1961) received the Dip1.-Ing. degree in 1984 and the Doctoral degree in 1988 both in Applied Mathematics from the University of Technology of Vienna/Austria. He started his professional experience 1984 as a research assistant at the Department of Economics of the University of Vienna. 1986/87 he attended the Institute for Advanced Studies in Vienna and in 1987 he joined the Austrian Electricity Board (Verbundgesellschaft) in its Electronic Data Processing department. His main interests are applications of econometric and Operations Research methods including expert system technology. (Österreichische Elektrizitätswirtschafts-AG (Verbundgesellschaft) Daten verarbeitung Am Hof 6a A-1010 Wien/Austria T +431/531 13 - 2948 Fax +431/531 13- 4191)

Short‐Term Load Forecast at Verbundgesellschaft (VG ‐ the Austrian Electricity Board) is presented. As the VG has only regional utilities and large industries as purchasers, classical forecast methods are not appropriate. Much more suitable is a plausibility check of a set of announced purchasers demands, for which an expert system has been developed for one to three days ahead forecasts. It has been realized with the help of a rule‐oriented expert system shell based on Prolog, and contains about 250 rules. Normal days as well as special days are considered. The prototype has been tested at the central dispatcher of the VG since autumn 1990. Results and acceptance by the users are promising. 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

A RESOLVER-TO-DIGITAL CONVERSION METHOD FOR FAST TRACKING

引用

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 1992年第5期39卷 369-378页

作者： YIM, CH HA, IJ KO, MS Department of Control and Instrumentation Engineering Automation and Systems Research Institute Seoul National University Seoul South Korea

In this paper, we propose a new resolver-to-digital (R/D) conversion method in which a bang-bang type phase comparator is employed for fast tracking. We eliminate from the R/D conversion loop the low-pass filter that is needed to reject carrier signal and noise. Instead, we employ two prefilters outside the R/D conversion loop that take the role of the low-pass filter. We can thereby construct a fast and accurate tracking R/D converter. Some simulation and experimental results as well as mathematical performance analysis are presented to demonstrate the superior tracking performance of our R/D converter over conventional tracking R/D converters.

关键词： Signal resolution Low pass filters Voltage-controlled oscillators Phase locked loops Tracking loops Shafts Magnetic separation Circuit noise Magnetic noise Phase noise

来源：评论

学校读者我要写书评

暂无评论

control OF INDUCTION-MOTORS FOR BOTH HIGH DYNAMIC PERFORMANCE AND HIGH-POWER EFFICIENCY

引用

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 1992年第4期39卷 323-333页

作者： KIM, GS HA, IJ KO, MS Department of Electronics The Central R & D Institute Daewoo Heavy Industries Limited Incheon South Korea Department of Control & Instrumentation Engineering and Automation and Systems Research Institute Seoul National University Seoul South Korea

In this paper, we attempt to control induction motors with maximum power efficiency as well as high dynamic performance by means of decoupling of motor speed (or motor torque) and rotor flux. For maximum power efficiency, the squared rotor flux is adjusted according to a minimum power search- algorithm until the measured power input reaches the minimum. Since the motor speed is dynamically decoupled from the rotor flux, this can be done successfully without any degradation of motor speed responses. Our controller depends on rotor resistance but not on stator resistance. However, the performance of our control scheme is robust with respect to variations in rotor resistance because an identification algorithm for rotor resistance is employed. Our identification algorithm for rotor resistance has some advantages over the previous methods. To demonstrate the practical significance of our results, we present some experimental results.

关键词： Induction motors Rotors Stators DC motors Torque control Voltage Inductance Optimal control Electrical resistance measurement Power measurement

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：