检索结果-内蒙古大学图书馆

International Symposium on Fault-Tolerant Computing (FTCS)

作者： S. Balaji L. Jenkins L.M. Patnaik P.S. Goel Control Systems Division ISRO Satellite Centre Bangalore India Department of Electrical Engineering Indian Institute of Science Bangalore India Department of Computer Science & Automation Indian Institute of Science Bangalore India

In a hard real-time distributed computing system (HRTDCS), all the tasks are required to meet their associated deadlines; a task not meeting its deadline leads to a catastrophic failure of the system. The authors consider an HRTDCS that executes both periodic and aperiodic tasks associated with timing, precedence, and resource constraints. The fault-tolerance capability in such a system is achieved through the use of time redundancy. The problem of workload redistribution for fault tolerance in an HRTDCS is studied. A graph model to represent the system workload is developed. Three performance measures for the analysis of an HRTDCS are defined. A nonpreemptive scheduling algorithm is proposed to distribute the workload of the operational nodes of the HRTDCS in the presence of both hardware and task failures. This task allocation strategy is applied to a practical system, namely, the HRTDCS onboard a spacecraft. The performance measures obtained for a typical system workload indicate that the algorithm is quite suitable for an HRTDCS with regard to uniform workload distribution.< >

关键词： Fault tolerance Real time systems Distributed computing Timing Fault tolerant systems Redundancy Performance analysis Scheduling algorithm Hardware Space vehicles

来源：评论

学校读者我要写书评

暂无评论

ON THE ROBUSTNESS OF LOW-ORDER SCHUR POLYNOMIALS

引用

IEEE TRANSACTIONS ON CIRCUITS AND systems 1988年第5期35卷 570-577页

作者： KRAUS, FJ ANDERSON, BDO JURY, EI MANSOUR, M Institute of Automatic Control ETH Zurich Zurich Switzerland Department of Systems Engineering Australian National University Canberra ACT Australia Department of Electrical and Computer Engineering University of Miami Coral Gables FL USA

Robust Schur stability conditions are obtained for polynomials of orders two to five. For n=2 and 3, the conditions obtained are related to stability of the corner points, while for n=4 and 5, the conditions are related to stability of corner and possible supplementary points. The number of points increases substantially as the polynomial order increases. The obtained results are of importance in the robust design of control systems. The difficulty in extending the approach to higher-order polynomials is discussed. Special cases for such extensions are mentioned. Further applications of the results obtained may be of use in the stability study of two-dimensional systems. Some examples for the application of the stability conditions are given and, in particular, the two counterexamples presented in the literature are discussed.

关键词： low-order Multidimensional systems control systems higher-order Polynomial Steady state stability study corners Point of inflexion Robustness

来源：评论

学校读者我要写书评

暂无评论

Psychoacoustically based scalar quantization of the LPC poles

Psychoacoustically based scalar quantization of the LPC pole...

引用

International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： A. Erell Y. Orgad J.L. Goldstein Department of Electronic Communication Control and Computer Systems Faculty of Engineering Tel-Aviv University Israel

The most straightforward way to incorporate knowledge of formant perception in LPC scalar quantization is by quantizing the LPC poles. The authors measured directly the perceptual sensitivity to changes in the poles during continuous speech, and used these data in the design of a scalar quantization scheme. The average pole-frequency just noticeable difference (JND) was found to strongly decrease with increasing formant bandwidth, and to depend to a lesser degree on the frequency. A considerable coding efficiency was achieved by utilizing the JND data and the measured distribution ranges of the pole frequencies. A 30 bits per frame quantization produced similar speech quality as that obtained with a standard 41 bits quantization of the reflection coefficients.< >

关键词： Psychology Quantization Linear predictive coding Frequency Bandwidth Testing Speech analysis Communication system control Knowledge engineering Bit rate

来源：评论

学校读者我要写书评

暂无评论

computerized intonator: design of a microprocessor pitch-aid

Computerized intonator: design of a microprocessor pitch-aid

引用

International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： C. Yehezkel M. Furst J.L. Goldstein Department of Electronic Communication Control and Computer Systems Faculty of Engineering Tel-Aviv University Ramat-Aviv Israel

Many profoundly hearing-impaired individuals that use hearing-aid devices suffer from poor auditory capacity, and therefore mainly rely on speechreading information. Previous studies suggest that presenting signals carrying prosodic information has great potential for improving speechreading. The authors present the computerized intonator, which is a microprogrammed acoustic pitch-aid device that provides the user in real-time with the fundamental frequency modulated by the amplitude envelope. The device implementation provides maximum flexibility for designing the output stimuli to suit individual needs. The benefit of the device is presently being evaluated using the connected discourse tracking test.< >

关键词： Microprocessors Signal processing algorithms Speech Auditory system Acoustic devices Frequency Testing Data mining Decoding Performance evaluation

来源：评论

学校读者我要写书评

暂无评论

On-line Fault Detection in Adaptive control systems by Using Kullback Discrimination Index

引用

IFAC Proceedings Volumes 1988年第9期21卷 1135-1140页

作者： K. Kumamaru T. Söerström S. Sagara K. Morita Department of Computer Science and Communication Engineering Faculty of Engineering Kyushu University Fukuoka 812 Japan Department of Automatic Control and Systems Analysis Institute of Technology Uppsala University P.O. Box 534. Uppsala Sweden Department of Electrical Engineering Faculty of Engineering Kyushu University Fukuoka 812 Japan

An on-line scheme to fault detection in adaptive control systems is proposed by introducing Kullbaek Discrimination Information (KDI) as a detection index. When a physical parameter change due to a failure has occurred in a system under adaptive control, the failure effect will hardly be visible in the output performance because of the adaptation mechanism. Such a parameter change is also difficult to detect by monitoring the regulator parameters, which are determined by a recursive identification based on the direct approach. Since the failure effect is reflected as a change in the predictor model used for the adaptive control design, the fault detection leads to a model discrimination problem. It has been shown that the KDI can be used as an effective distortion measure for the model discrimination and the index can be applied in a modified form to detect a fault on-line. Simulation studies on a second order damped oscillatory system have been carried out to demonstrate the efficiency of the method.

关键词： Adaptive control fault detection Kullback discrimination information model discrimination parameter estimation

来源：评论

学校读者我要写书评

暂无评论

Frequency Domain Conditions for the Robust Stability of Linear and Nonlinear Dynamical systems

Frequency Domain Conditions for the Robust Stability of Line...

引用

American control Conference (ACC)

作者： S. Dasgupta P.J. Parker B.D.O. Anderson F.J. Kraus M. Mansour Department of Electrical and Computer Engineering University of Iowa Iowa IA USA Department of Systems Engineering Australian National University ACT Australia Department of Automatic Control and Industrial Engineering Swiss Federal Institute of Technology Zurich Switzerland

This paper presents general frequency domain criteria for the robust stability of systems with parametric uncertainities. The criteria are applied to the robust stability verification of LTI systems with or without ti... 详细信息

关键词： Frequency domain analysis Robust stability Nonlinear dynamical systems Polynomials Differential equations Feedback Delay effects Adaptive control Cities and towns systems engineering and theory

来源：评论

学校读者我要写书评

暂无评论

A power method for the structured singular value

A power method for the structured singular value

引用

IEEE Conference on Decision and control

作者： A. Packard M.K.H. Fan J. Doyle Systems and Control Sciences Honeywell Systems and Research Center Inc. Minneapolis MN USA Department of Electrical and Computer Engineering University of California Santa Barbara CA USA Department of Electrical Engineering & Systems Research Center University of Maryland College Park MD USA Department of Electrical Engineering Pasadena CA USA

An iterative algorithm is presented to compute lower bounds for the structured singular value ( mu ). The algorithm resembles a mixture of power methods for eigenvalues and singular values, since the structured singular value can be viewed as a generalization of both. If the algorithm converges, a lower bound for mu results. The authors prove that mu is always an equilibrium point of the algorithm. However, since in general there are many equilibrium points, some heuristic ideas to achieve convergence are presented. Extensive numerical experience with the algorithm is discussed.< >

关键词： Iterative algorithms Eigenvalues and eigenfunctions Convergence Upper bound Yield estimation Performance analysis Robustness Uncertainty control systems Educational institutions

来源：评论

学校读者我要写书评

暂无评论

Benchmark Problems for computer-Aided control System Design

引用

IFAC Proceedings Volumes 1988年第8期21卷 1-6页

作者： D.K. Frederick M. Rimer Electrical Computer and Systems Engineering Department Rensselaer Polytechnic Institute Troy 12180 USA Stability Control and Flying Qualities Group B21-35 Grumman Aerospace Corporation Bethpage 11714 USA

The need for having benchmark problems for the evaluation of software for computer-aided control system analysis and design is discussed. The two benchmark problems that have been released to date by the Benchmark Working Group of the Technical Committee on computer-aided control System Design of the IEEE control systems Society are described, as are the plans for future problems. Information that has been learned about the preparation, distribution, and dissemination of results for this type of problem is included.

关键词： computer-aided design benchmark problems computer analysis computer programs control-system design

来源：评论

学校读者我要写书评

暂无评论

An Integrated Approach to controls and Diagnostics: The 4-Parameter controller

An Integrated Approach to Controls and Diagnostics: The 4-Pa...

引用

American control Conference (ACC)

作者： C. N. Nett C. A. Jacobson A. T. Miller Control Systems Laboratory GE Corporate Research and Development Center Schenectady NY USA Department of Electrical and Computer Engineering Northeastern University Boston MA USA

In this paper we present a theoretical basis for an integrated approach to the design of reliable control systems. In this approach, the control and diagnostic modules of a reliable control system are designed together, instead of independently, thereby accounting for the interactions which occur between these two modules in a functioning reliable control system. The approach makes use of a significant generalisation of the familiar 2-parameter controller known as the 4-parameter controller. This controller has two vector inputs and not one, but two vector outputs; correspondingly, this controller is comprised of not two, but four matrix parameters. The additional controller output is monitored to detect and isolate sensor and actuator faults, thereby providing the controller with diagnostic capabilities, or "intelligence," in addition to its control capabilities. Using a parameterization of all stabilising 4-parameter controllers, the fundamental limitations and inherent tradeoffs governing the design of reliable control systems are clarly delineated, with special attention given the issues of uncertainty and control/diagnostic interaction. Several means for resolving these desig tradeoffs are proposed, and illustrated by way of non-trivial examples. These results are expected to pave the way for the achievement of improved overall control/dignostic performance in reliable control systems, and also to pave the way for the achivement of significant complexity reductions in both the design and implementation of reliable control systems.

关键词： control systems Fault detection Signal processing Research and development Jacobian matrices Reliability theory Monitoring Actuators Uncertainty Intelligent control

来源：评论

学校读者我要写书评

暂无评论

Statistical Analysis of the Overdetermined Yule-walker Estimator of Frequencies of Multiple Sinusoids

引用

IFAC Proceedings Volumes 1988年第9期21卷 1035-1040页

作者： P. Stoica T. Soderstrom F.-N. Ti B. Friedlander Department of Automatic Control Polytechnic Institute of Bucharest Splaiul Independentei 313 R-77206 Bucharest Romania Automatic Control and Systems Analysis Group Department of Technology Uppsala University P.O. Box 534 S-751 21 Uppsala Sweden Automatic Control and Systems Analysis Group Department of Technology Uppsala University P.O. Box 534 S-751 21 Uppsala Sweden on leave from Department of Mechanical and Electrical Engineering Shandong College of Light Industry Jinan PRC Saxpy Computer Corporation 255 San Geronimo Way Sunnyvale CA 94086 USA

The estimation of sinusoidal frequencies by the overdetermined Yule-Walker (OYW) Method is considered. An explicit expression is derived for the asymptotic covariance matrix of the estimation errors. The effect of increasing the number of Yule-Walker equations on estimation accuracy is analyzed. The asymptotic estimation accuracy of the OYW method is compared to the best achievable accuracy corresponding to the Cramér-Rao bound

关键词： system identification parameter estimation sinusoidal frequencies Yule-Walker methods asymptotic distribution

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：