摘要:

AbstractThe 1984 UK Finance Act introduced changes in tax legislation with consequences for both capital and revenue expenditure on plant. The one- and two-cycle rent models for capital equipment replacement and the infinite-cycle discounted-cost model are extended here to incorporate the new tax features. A specific replacement problem is used as the basis of an analyis of the sensitivity of the optimal replacement period to parameters. Whilst all these models are consistently insensitive to the new tax legislation, there is no consistency across models with respect to which parameters dominate choice of optimal replacement period.

ISSN:0160-5682    

DOI:10.1057/jors.1987.170

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractThe Fleet Structures Model is a predictive computer model under development by the Sea Fish Industry Authority. Its purpose is to simulate aspects of the structure and operation of the UK sea-fishing fleet in order to make comparative appraisals of fleet-management policy scenarios under varying assumptions about the behavioural environment. The model operates in yearly incremental steps, providing feedback between the fleet operation, the expected changes in fleet structure, fish prices and the state of fish stocks. It is an analytic model, and is mainly deterministic with stochastic elements. Implementation is in programs written in Pascal. This paper presents an overview of the model, and highlights aspects of its development and implementation.

ISSN:0160-5682    

DOI:10.1057/jors.1987.171

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractA mathematical programming model is proposed to select an optimal cooperation policy between autonomous service networks for dispatching purposes. In addition to traditional characteristics such as network topology and station locations, this model takes into account‘political’constraints on minimum response-time in certain subzones. Such constraints are translated into performance requirements, which are imposed on the cooperation policy. Testing the model under different assumptions can be useful for analysing various cooperation policies. The paper formulates a mathematical programming model, derives example policies for various circumstances, and tests the sensitivity of the resultant policies to some parameters, such as the penalty for not providing service, and distances between adjacent networks. The paper suggests also a less constrained approach, which entails a linear programming model. A comparison between the two approaches is presented.

ISSN:0160-5682    

DOI:10.1057/jors.1987.172

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractThe aim of the paper is to show how Shannon's entropy may be used for optimal grouping of state spaces of discrete stochastic systems. Compositions (ordered partitions) of discrete state spaces and their entropic optimality have been defined, and optimal compositions were computed as solutions of a dynamic programme. Uniform and binomial systems were used for illustrations. Sturges' rule was reinterpreted.

ISSN:0160-5682    

DOI:10.1057/jors.1987.173

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractThe hypothesis that firms simultaneously determine their research and development, investment, dividend and effective-debt policies generally is substantiated in the financial literature. The determinants of research and development, dividend, investment and financing decisions of 303 firms are estimated econometrically during the 1976-1982 period. Moreover, an optimization model is estimated for a firm that seeks to minimize underachievement of desired investments, dividend and R&D and minimize the underachievement of desired effective debt. Management gains additional insights to increase the achievement of maximizing research and development expenditures at the expense of paying dividends and undertaking investments.

ISSN:0160-5682    

DOI:10.1057/jors.1987.174

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractNetwork oligopoly models have been recently proposed as an alternative to general equilibrium models for analysing conflict situations between spatially separated firms. However, the oligopoly models are, from an algorithmic standpoint, less well understood than their equilibrium counterparts. In this paper we propose four iterative schemes for computing Cournot-Nash equilibria on congested transportation networks. The algorithms will be analysed theoretically, and computational results will be provided (i) for an oligopoly test problem, and (ii) for a small-scale network oligopoly problem.

ISSN:0160-5682    

DOI:10.1057/jors.1987.175

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractIn modern processor-controlled systems, it is common to find a central processor polling a number of message queues, where at most one message is processed from each queue during one polling cycle. This paper shows how one important parameter can be estimated quickly, namelythe cycle-time distribution. This is the distribution of times taken for the cyclic server to perform one complete cycle in its continuous scan of a number of queues. The method of solution is to identify various constraints which will determine the cycle-time distribution, formulate them as linear inequality and equality constraints and, by determining an appropriate objective function, apply the simplex method to find upper and lower bounds on the values taken by the cycle-time distribution itself. A great strength of this technique is its overall simplicity, which enables it to be used to obtain important results very quickly and cheaply.

ISSN:0160-5682    

DOI:10.1057/jors.1987.176

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractWe discuss generalized travelling-salesman problems where nodes are visited either once or not, and a penalty cost is incurred for each unvisited node. The generalization includes the longest-path problem and the shortest-path problem with specified nodes to be visited. A new transformation of generalized into standard travelling-salesman problem is presented. We give computational results for the shortest-path problem with specified nodes. The transformation makes it possible to solve symmetric problems with a relatively large number of specified nodes, which cannot be solved by previously published algorithms based on a linear assignment relaxation. Furthermore, we show how to obtain improved lower bounds for a special Euclidean-type variant.

ISSN:0160-5682    

DOI:10.1057/jors.1987.177

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractAn earlier paper by the authors discussed the importance of credit policies in the basic economic-order-quantity inventory model. Recently this analysis has been questioned, and a different result produced from similar initial assumptions. This paper resolves the discrepancy, confirming the authors' original analysis.

ISSN:0160-5682    

DOI:10.1057/jors.1987.178

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractThis paper presents a literature survey on the use of supercomputers in operational research.

ISSN:0160-5682    

DOI:10.1057/jors.1987.179

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor