摘要:

AbstractMany writers and practitioners have mentioned the difficulties that result from randomness in visual interactive simulation or animated simulation modelling. This paper discusses the use of VIS to model transient system behaviour, and proposes some approaches to stochastic VIS modelling which may be helpful in overcoming the difficulties.

ISSN:0160-5682    

DOI:10.1057/jors.1989.104

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn expert system to assist in admitting students onto a part-time postgraduate course has been developed through three phases, using an expert systems shell. The first phase was an unstructured approach, which demonstrated the feasibility of the system but led to difficulties in development. The second phase followed a simplified systems analysis and resulted in a more comprehensive and structured system. However, its operation was cumbersome and unfriendly. The third phase involved developing a mathematical model of the decision-maker's judgement and led to a simpler, more effective and easier to use system.

ISSN:0160-5682    

DOI:10.1057/jors.1989.105

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn optimal solution is found to a real-world problem which has the characteristics of a multiple travelling-salesman problem. It deals specifically with methods of obtaining the‘best’routeing for four vehicles which provide a daily service from a depot to 38 locations. The solution technique uses both heuristic and exact algorithms to derive the order for visits to the 38 locations.

ISSN:0160-5682    

DOI:10.1057/jors.1989.106

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe paper describes a simulation model that was built to predict the production output of a printed circuit-board manufacturer. Such a prediction with traditional forecasting tools is difficult owing to varying lot sizes, designs, processing time, product mix, machining capacity and fluctuating work-force. The model was built with discrete-event orientation using SIMPLE_1 simulation language. Model-validation was made over a period of 1 month by comparing the simulation and actual outputs as well as the supervisor's predictions. The model was later used to study the effects of varying manning levels and equipment capacities on output, as well as to evaluate proposed changes to the existing system.

ISSN:0160-5682    

DOI:10.1057/jors.1989.107

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper describes three case studies which investigated issues relating to the implementation and management of advanced information technology. The benefits derived from information technology were found to vary from one organization to another. These studies provide further evidence to support earlier research findings that senior management has an important role to play in the effective exploitation of information technology, and that the investment approach taken by an organization has a significant effect on the development of computer-based information systems. The effectiveness of a system depends not only on applying the appropriate technology, but also on how successfully technical and behavioural issues are resolved.

ISSN:0160-5682    

DOI:10.1057/jors.1989.108

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe optimal flow control of aG/G/cfinite capacity queue is investigated by approximating the general (G-type) distributions by a maximum entropy model with known first two moments. The flow-control mechanism maximizing the throughput, under a bounded time-delay criterion, is shown to be of window type (bang-bang control). The optimal input rate and the maximum number of packets in the system (i.e. sliding window size) are derived in terms of the maximum input rate and the second moment of the interinput time, the maximum allowed average time delay, the first two moments of the service times and the number of servers. Moreover, the relationship between the maximum throughput and maximum time delay is determined. Numerical examples provide useful information on how critically the optimal throughput is affected by the distributional form of the input and service patterns and the finite capacity of the queue.

ISSN:0160-5682    

DOI:10.1057/jors.1989.109

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe performance of a telecommunication system consisting of a set of transmitters with finite capacity buffers is modelled with a Markovian queueing network, and its tandem behaviour is approximated, in steady state. In this system, a fraction of the units which, at the instants of their arrival at each transmitter, find it busy may retry to be processed by merging with the incoming arrival units at the same transmitter after a fixed delay time. The performance of this system is approximated by a recursive algorithm, in steady state. Furthermore, the approximation outcomes are compared against those from a simulation study. In summary, our numerical results indicate that approximating the non-renewal superposition arrival, the non-renewal overflow and the non-renewal departure processes at each node of the network can be approximated with compatible Poisson processes.

ISSN:0160-5682    

DOI:10.1057/jors.1989.110

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe purpose of this paper is to present a multiple-attribute error analysis in order to make more precise discrimination among competing alternatives under uncertain environments. Measurements of (especially non-monetary) attribute ratings and assessments of attribute weights are often highly imprecise and subjective, yet most analytical methods lack provisions for handling imprecise data. This paper describes how to measure the propagation of errors in the value of alternatives due to individual attribute rating and weight errors. We also measure the errors in attribute weight due to imprecise preference information from the decision-maker.

ISSN:0160-5682    

DOI:10.1057/jors.1989.111

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractA very efficient and statistically sound random-number generator of the prime modulus multiplicative congruential method is devised for 16-bit microcomputers (8-bit machines have to be double-precisioned). This generator combines several generators, and cycles every (215-20)2numbers with 215-20 different numbers in one cycle. When precision is relatively unimportant, this generator is demonstrated to be a good random-number generator.

ISSN:0160-5682    

DOI:10.1057/jors.1989.112

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractA previous paper presented a new model of manpower systems which was derived from the fundamental concepts of thermodynamics. Of even greater methodological significance, however, is that this model is also connected with statistical physics at the level of quantum mechanics.

ISSN:0160-5682    

DOI:10.1057/jors.1989.113

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor