摘要:

Recent progress in microprocessor-based relaying systems and the technology involved in the new measurement systems for assessment of on-line dynamic security of electric power systems are described. The technique of obtaining the measurements from selected locations on interconnected electric power systems is presented. The measurements require a number of algorithms that have been developed. A comparison of the different approaches has also been conducted using a realistic system for confirmation of the developed technique.

ISSN:0020-7721    

DOI:10.1080/00207729008910485

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Systems dynamics has been used to model and simulate a variety of environments, e.g. economic, social and political, which require quantification or some types of human behaviour. The lack of empirical verification of the relationships in the systems dynamics models has often been criticised. Nevertheless, the methodology is effective in dealing with time-varying (dynamic) interactions among components of the analysed system. The effectiveness of systems dynamics as a methodology for modelling, simulating and analysing real-life systems can be significantly increased if it is extended to deal with imprecise and vague variables or events. Such an extension requires: (1) treatment of imprecise and vague input variables as fuzzy variables: (2) use of fuzzy arithmetic in the level, rate and auxiliary equations when fuzzy numbers are involved; and (3) replacement of some of the relationships in the systems dynamics models either with conditional statements including fuzzy variables, or with fuzzy algorithms.

ISSN:0020-7721    

DOI:10.1080/00207729008910486

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Reachability conditions are developed for discrete single-input-single-output variable structure control systems described by linear mathematical models in general state-space form to reach a switching function from anywhere in state space. Stability conditions of a sliding mode are investigated. A modified algorithm is proposed to simplify the design procedure. Practical application to a thermal process has been achieved by using the modified algorithm to show the potential for development and practical results are compared with those using the classical PID controller design.

ISSN:0020-7721    

DOI:10.1080/00207729008910487

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Very few researchers have considered inventory models with partial backlogging. The models developed earlier considered a fraction of demand to be backordered while the remaining fraction is lost during the stock out period. In this paper we have developed an inventory model with partial backlogging, redefining the demand rate at a particular instant as a function of the amount of orders already backlogged at that instant of time. Infinite replenishment rate and zero lead time are assumed. Expressions for optimum order quantity and optimuim value of maximum inventory are obtained by minimizing the total system costs. The model is illustrated with a numerical example, including sensitivity analysis with respect to the backlogging parameter.

ISSN:0020-7721    

DOI:10.1080/00207729008910488

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

New criteria for the non-existence of zero input limit cycles in two-dimensional digital filters are presented. The criteria are formulated using the state-space representation and are based on results concerning the 2-D Lyapunov equation.

ISSN:0020-7721    

DOI:10.1080/00207729008910489

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Modified age replacement policies, where a system is not always as good as new after each maintenance, are discussed. The expected total discounted cost for an infinite time-span, introducing some costs and a continuous type discount rate is applied as a criterion of optimality, and the optimum policies minimizing this cost are obtained. It is shown that, under certain conditions, there exists a finite and unique optimum policy. Relations to the existing publications are also shown.

ISSN:0020-7721    

DOI:10.1080/00207729008910490

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0020-7721    

DOI:10.1080/00207729008910491

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor