摘要:

In general, computer systems with high reliability can be achieved by redundancy techniques. In this paper, we are interested in fault-tolerant computer architectures from the viewpoint of hardware redundancy. In particular, we discuss a three-unit hybrid redundant system which is composed of a two-unit multi-system and of a standby redundant (single) unit. We derive the reliability and the performance-related reliability measures by applying Markov renewal processes (MRPs). We compare such a three-unit hybrid redundant system with a two-unit multi-system, and show how the reliability and the performance can be improved by introducing a standby redundant (single) unit. We show the dependence of the types of repair time distributions on availability, MTBF, and computation availability by assuming gamma distributions with shape parameter k, where k varies. We further show the dependence of coverage on availability, MTBF, and computation availability.

ISSN:0020-7721    

DOI:10.1080/00207728208926327

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

We propose a method for obtaining the maximum likelihood estimates of the unknowns. To ensure that the identified system is stable, it is necessary to describe the stability condition in a form of constraint function which is suitable for the numerical optimization of the likelihood function. This is done by decomposing the auto-covariance matrix of order 𝓅+ 1 into a product of a triangular matrix and its transpose. Some numerical results are presented which indicate that the new method is useful particularly for a small size of data sets.

ISSN:0020-7721    

DOI:10.1080/00207728208926328

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A class of minimax policies and its optimality are specified for portfolio choice problems, where the mean and variance parameters are not completely known but statistically estimated from sample observations. Implications of such optimal minimax policies in applied stochastic decision models are also indicated in brief.

ISSN:0020-7721    

DOI:10.1080/00207728208926329

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

In this paper a hybrid combination of non-linear programming and econometric modelling techniques is proposed to derive optimal economic plans from largo dynamic econometric models. The required algorithms are discussed and applied to a multi-sectoral dynamic model of the U.K. economy. It is argued that the non-linear programming framework for the formulation of economic policy is superior to the conventional steering approach, since it takes account of asymmetry in preferences and distinguishes between long-term optimality and short-term feasibility considerations. The optimal reflationary mix shows marked improvements in welfare and at the same time ensures feasibility of selected target variables. The results also show that the problems of slow output and productivity growth are located in a few key industries and that the reflationary package does not entirely remove the problems of import penetration and secular decline of Britain's manufacturing industry.

ISSN:0020-7721    

DOI:10.1080/00207728208926330

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A novel algorithm for the computation of total service time in a packet-switched network is presented and analysed. Its adaptability to any network design without necessitating changes in the algorithm, in comparison to a simulation which would most likely require changes, perhaps extensive ones, in the program structure for each design, makes it a powerful tool for analysis. Further refinements in the algorithm are then discussed along with an easily constructed graphical representation that points out how they may be achieved. Results can be obtained regardless of the statistical distribution with which the message arrived at the source node. The exact service time is computed by the algorithm presented, as opposed to an approximation that characterizes the usage of the independence assumption in this class of problems. The algorithm uses a true-to-life model in deriving the results reported.

ISSN:0020-7721    

DOI:10.1080/00207728208926331

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Sensitivity of continuous system eigenvalues to finite difference discretization is determined from low-order Taylor approximations to quantized system variables. Compensation for discretization is possible through either state feedback parameter augmentation or higher-order forward path integration.

ISSN:0020-7721    

DOI:10.1080/00207728208926332

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This paper addresses the general formulation of the linear-quadratic-gaussian (LQG) problem for stochastic singularly perturbed systems. It has been found that the time-Scale phenomena between the fast state variable and the stochastic variable plays a crucial role in formulating a meaningful LQG problem for the above system. A well-posed LQG problem for the stochastic singularly perturbed linear system with the fast state having a white noise component has been presented.

ISSN:0020-7721    

DOI:10.1080/00207728208926333

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The linear system Mx¨ + (∝ M+ β) K)[xacute] + KX= F with M singular, is decomposed into two linear systems, one singular and one non-singular. The singular ono is solved explicitly in terms of M, K, f, a, S and analysed.

ISSN:0020-7721    

DOI:10.1080/00207728208926334

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The formal reachability property for a pair of matrices (A, B) over the polynomial ring ℛ = R[d1..., dk] inksymbols with real coefficients is considered where A isnbyn, B isnbymwith integersmbeing fixed. Reachability is defined as the property that ImRscr;[A|B]= ℛnnwhere [A |B] = [B, AB,..., An−1B] is the formal reachability matrix for the pair (A, B). This abstract property is first characterized by a numerical rank criterion over the field of complex numbers. Then it is shown that reachability is generic if and only ifk<m. It is hoped that the results presented will stimulate further research on polynomial output feedback controllers' for the delay-differential and multidiscrete-type systems.

ISSN:0020-7721    

DOI:10.1080/00207728208926335

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor