ISSN:0160-5682    

DOI:10.1057/jors.1988.183

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1988.184

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractA five-stage approach to mathematical modelling is reviewed. It is shown how this can be used as a framework for introducing the teaching of simple stock control and distribution, financial modelling and planning, linear programming, decision trees, network analysis and discrete-event simulation. The framework puts emphasis on the conceptualization and verbalization stages, which provides a unifying link for the techniques described and is found substantially to improve formulation skills.

ISSN:0160-5682    

DOI:10.1057/jors.1988.185

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractIn a 1982 paper, Rosenhead and Thunhurst analysed the origins, development and current practice of operational research from an historical and materialist perspective. A critique of the theoretical and practical implications of their arguments is presented in this paper, along with an alternative interpretation of the historical facts. The relationship between operational research and the forces affecting the development of the capitalist society are discussed within this context.

ISSN:0160-5682    

DOI:10.1057/jors.1988.186

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractIn 1986, Hampshire Local Education Authority reviewed its provision of non-compulsory education in Southampton and proposed the closure of a sixth-form college. The reason given for the closure was an expected fall in rolls, but the review appears to have been motivated primarily by financial pressures. This paper re-examines the evidence put forward by the LEA to forecast rolls. It is found that outdated methods, inadequate data sources and superficial analyses were used to produce the forecast. An alternative analysis shows that the proposed closure, if implemented, would run counter to the objectives of the reorganization. It is argued that the LEA chose to consult on the wrong problem, and that the real issue was a lack of funds in the education budget.

ISSN:0160-5682    

DOI:10.1057/jors.1988.187

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractRule induction is a machine learning technique which has been used in knowledge acquisition for expert systems. This paper explores its use for the interpretation of the results from simulation of investment models in order to identify the major risks.

ISSN:0160-5682    

DOI:10.1057/jors.1988.188

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractThe calculation of certain performance measures in queueing network simulation using operational analysis is presented. A systematic approach to the gathering of output and calculation of performance measures for quantitative system-performance analysis is demonstrated. The assumptions used in operational analysis to derive performance-measure relationships are verifiable by examining the output generated by the simulation. Any errors in assumptions revealed by the output may be measured, and these error measures used to determine correction terms. The performance-measure relations may still be used, even when the assumptions upon which they are based are in error, by adding these correction terms to the performance-measure values obtained. The results will be exact values for the performance measures over the period of the simulation. Calculations of performance measures, error measures and correction terms are illustrated with an example queueing network simulation.

ISSN:0160-5682    

DOI:10.1057/jors.1988.189

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractThis paper considers the problem of locating a single mobile service unit on a networkGwhere the servicing of a demand includes travel time to a permanent facility which is located at a predetermined point onG. Demands for service, which occur solely on the nodes of the network, arrive in a homogeneous Poisson manner. The server, when free, can be immediately dispatched to a demand: the service unit travels to the demand, performs some on-scene service, continues to the permanent facility, where off-scene service is rendered, and then it returns to its‘home’location, where possibly additional off-scene service is given. Previous research has examined the same problem, however without the presence of a permanent facility. The paper discusses methods of solving two cases when the server is unable to be immediately dispatched to service a demand: (1) the zero-capacity queueing system; (2) the infinite-capacity queueing system. For the first case we prove that the optimal location is included in a small set of points in the network, and we show how to find this set. For the second case, we present an 0(n3) algorithm (nis the number of nodes) to obtain the optimal location.

ISSN:0160-5682    

DOI:10.1057/jors.1988.190

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractThis paper describes a partitioning algorithm based on the Benders decomposition to solve net import spatial equilibrium models. The method decomposes the problem into a linear master problem and a quadratic subproblem. It is shown that the quadratic subproblem is trivial, and the associated dual variables can be determined through ordinary calculus. Therefore, the quadratic spatial equilibrium problem is solved iteratively by using linear programming software.

ISSN:0160-5682    

DOI:10.1057/jors.1988.191

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractThe economic lot-scheduling problem for the single-machine, n-item scheduling problem has received attention in a number of journals. One approach is to define a sequence (called the fundamental cycle) in which every item is made at least once, and then to determine the length of production runs consistent with the aggregate inventory level which will maximize the length of the cycle duration. The assumption that production is switched from one item to the next only when the inventory level of the latter reaches zero is often used in heuristic solutions to these models. This paper illustrates the conditions in which the‘zero-switch’rule is a necessary condition at the optimal solution for situations in which demand is continuous and production capacity equals aggregate demand.

ISSN:0160-5682    

DOI:10.1057/jors.1988.192

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor