摘要:

A new class of observers for non-linear uncertain dynamical systems is proposed. The non-linearity and uncertainty in the systems are assumed to be bounded. The bound is however unknown. Adaptive schemes are designed for the estimation of the bound. The observer, based on this estimation, is then able to estimate the system's state regardless of the realization of the uncertainty.

ISSN:0020-7721    

DOI:10.1080/00207729008910416

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Observer design problems of fasl sampling models with the two–time–scale property are considered. Two systematic design approaches (i.e., two–stage and direct) are developed, and the relationships between them are clarified. Following these results, the observer design problems of both a prediction type and a current type are investigated. Finally, the relationships between the fast/slow sampling version and the continuous–time version are discussed.

ISSN:0020-7721    

DOI:10.1080/00207729008910417

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Recently it was shown for continuous and discrete-time stationary linear systems that the output stabilizability property of systems can be used to realize ‘almost–positive–rear configurations that may facilitate the implementation of simple, stable, adaptive, and other non–linear controllers. This paper attempts to extend these concepts to time–varying linear systems. It is shown that systems that can be stabilized via static or dynamic output feedback become ’almost–passive‘ via some corresponding parallel feedforward. The proof of the robust stability of simple adaptive control of non–stationary almost–passive systems is also presented.

ISSN:0020-7721    

DOI:10.1080/00207729008910418

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A complex dynamical behaviour called ‘chaos’ is observed in mathematical models expressed in the form of recurrences with non-unique inverses. The attractive limit sets of an endomorphism are located in phase plane domains bounded by segments of critical curves and called absorptive areas. Frequently in such an endomorphism, the sequence of consequents of a point belonging to an initial condition domain have an apparently erratic movement in a bounded domain of the (x, y) plane called a chaotic area. The variation of a parameter can modify the nature of these chaotic areas. Different bifurcations occurring in chaotic areas are described in this paper and are illustrated by the study of examples.

ISSN:0020-7721    

DOI:10.1080/00207729008910419

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper presents two newly developed probabilistic models to perform reliability and availability analysis of three unit redundant systems with human errors. Model 1 represents a 2–out–of–3 unit system whereas Model 2 is concerned with a three non–identical unit standby system. The supplementary variables method, the Markov approach and Laplace transforms are employed to perform analysis. For both models system reliability, steady–state availability, mean time to failure and variance of time to failure formulae are developed. A number of plots are presented to demonstrate the effect of human errors and hardware failures.

ISSN:0020-7721    

DOI:10.1080/00207729008910420

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Decentralized smoothing algorithms are described for parallel-processing of the multisensor data obtained through linear discrete-time systems. The global fixed-interval smoother of backward-pass in time is used, modified so as to use the U-D factorization. Two cases are considered for the problems of decentralized smoothing and smoothing update: when the local forward-pass information filtered estimates are available, and when the local-smoothed estimates are available. It is then shown that the resulting algorithms are the dual versions of algorithms in a forward-pass realization derived by authors. The situation where the data at each local processor are to be time-sequential is also examined.

ISSN:0020-7721    

DOI:10.1080/00207729008910421

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A general separable class of stochastic multiobjective optimization problems with perfect state information is considered. A generating approach using a stochastic multiobjective dynamic programming method is developed to find the set of non-inferior solutions. The results reveal the variation of the optimal weighting coefficient vector along a non-inferior trajectory. Non-separability is not an inherent property of dynamic programming. A general class of non-separable dynamic problems can be transformed into corresponding separable multiobjective dynamic programming problems. Multiobjective dynamic programming is shown to be a separation strategy to solve non-separable dynamic programming.

ISSN:0020-7721    

DOI:10.1080/00207729008910422

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Bounded input-bounded output stability of internally bilinear systems whose zero state response is homogeneous in the input of degree two is examined. Both necessary and sufficient conditions for bounded input-bounded output stability are derived which generalize the linear system criterion of Chen (1970, Theorem 8.1).

ISSN:0020-7721    

DOI:10.1080/00207729008910423

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A method of transient simulation for any structure of gas network is described. This method is based on the generalization that the idea of the node, including grid points along pipes, multi-junctions and pipe ends, be treated as off-takes with the demand equal to zero. Two numerical formulations of this method are given.

ISSN:0020-7721    

DOI:10.1080/00207729008910424

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A general weakness of instruction pipelines is ‘bubbles’ or ‘holes’ in the pipeline due to conditional branch instructions. Most of the solutions (Lee and Smith 1984) to the branch problem attempt to predict whether or not a branch will be taken. If the prediction is correct, then the correct sequence of instructions can be initiated without delay. The performance of an instruction pipeline is analyzed to give a measure of the efficiency or utilisation of the pipeline segments in terms of the probability of correct branch prediction (referred to as the prediction accuracy). The analysis is based on the space-time relationship. The performance of an instruction pipeline with both equal and unequal segment times is analysed incorporating the effect of two types of conditional branch instructions in the instruction sets of computers. The results of the analysis enable one to study the sensitivity of the performance of an instruction pipeline to the number of conditional branch instructions and the probability of correct branch prediction as well as to estimate the utility of the different branch prediction strategies that have been proposed recently (Lee and Smith 1984). Although it is extremely difficult to obtain the value of 1 for prediction accuracy, this study reveals that a value of 0.8 can give reasonably good values of utilization.

ISSN:0020-7721    

DOI:10.1080/00207729008910425

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor