ISSN:0160-5682    

DOI:10.1057/jors.1985.1

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractAfter outlining the background, the results are given of a Swedish simulation of the effects on unemployment and on the economy of different forms of government subsidy to industry. The influence of different rates of expansion of the public sector is also discussed.Ways in which O.R. in the U.K. might follow up the Swedish work are also discussed, with particular reference to improving the competitive position.

ISSN:0160-5682    

DOI:10.1057/jors.1985.2

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThis paper outlines a generalized public-sector project selection model using linear goal programming and demonstrates its application using data from the energy-based sector in Trinidad and Tobago, a small developing country in the Caribbean. The decision maker's influence on the project portfolio selected is demonstrated by varying parameters, such as the priority structure and the level of availability of key resources. Goal programming emerges as a powerful tool available for use by public-sector planners in developing countries faced with the challenge of formulating an appropriate public-sector investment programme.

ISSN:0160-5682    

DOI:10.1057/jors.1985.3

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThis paper reports on a study initiated to check the validity of an existing six-monthly block replacement policy for a set of filling valves in a canning line. After dealing with inadequacies in the data and changing to a production-based time measure, the paper shows how a renewal function measure of the expected number of valve replacements was obtained and led to the conclusion that the current block replacement policy could not be justified.The possibility of an age-based replacement policy being of value remained. In order to model such a policy, it was necessary to reverse the usual analysis of renewal-type processes in that an estimate was required of the distribution function of time between renewals, given the renewal function.A finite optimal replacement age was found which depended upon the objective being to minimize a measure of downtime due to replacements, or operating costs attributable to replacements. Calculations were further complicated by part of the plant having a finite remaining life before being upgraded.

ISSN:0160-5682    

DOI:10.1057/jors.1985.4

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractLogit models attempt to answer the following question. Given a set of alternatives, each with multiple attributes, what is the probability that a decision maker will choose a certain alternative? Initially psychologists, then economists and marketing strategists, more recently transportation policy makers and design engineers have employed logit models. A brief review of these models is given in an attempt to show their relevance to more general decision-making situations, and their descriptiveness of human decision-making processes. A new model which synthesizes the desirable features of earlier models is then presented. The new model is applied to an actual case of predicting customer purchase probabilities for a particular brand of an industrial product. The prediction capability of the model is externally validated statistically, using real data, by comparing model results with the actual market share of the company.

ISSN:0160-5682    

DOI:10.1057/jors.1985.5

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThis paper compares the performance of CUSUM and smoothed-error tracking signals for monitoring the adequacy of exponential smoothing forecasts. Previous research has favoured the CUSUM. However, there is some evidence that the performance of the smoothed-error signal can be improved by a simple modification in its application: the use of different smoothing parameters in the tracking signal and the forecasting model. The effects of this modification are tested using simulated time series. We conclude that the CUSUM is robust to the choice of forecasting parameter, while the smoothed-error signal is not. The CUSUM is also more responsive to small changes in the time series, regardless of the parameters used.

ISSN:0160-5682    

DOI:10.1057/jors.1985.6

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractTwo different statistical models have been frequently used for short-term forecasting. The first, involving seasonal indices, is easy to understand but can lead to problems of instability. The second, transcendental functions (mixtures of sine waves), tends to be much more stable but is difficult for the user to understand. In this paper, we explain an approach that combines the benefits of the two types of models.

ISSN:0160-5682    

DOI:10.1057/jors.1985.7

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe returns to research are uncertain. It is shown that, if returns are marginally diminishing in relation to effort, a simple probabilistic argument favours the idea of splitting the research effort into two (or more) semi-independent parts. An example is drawn from the field of plant breeding. The argument is analogous to that first developed by Daniel Bernouilli in his invention of utility.

ISSN:0160-5682    

DOI:10.1057/jors.1985.8

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractSome algorithms are described for solving plant location problems with non-linear warehousing costs. The heuristic procedures are flexible with respect to the type of warehousing cost structure permitted, and may be used to solve fixedp-median location problems as well as problems in which the numbers and locations of warehouses in solution are jointly determined as a trade-off between transportation and fixed and operating plant costs. Computational experience is reported on some well known problem sets in which the economies of scale in production are continuously concave. Comparisons with other solution methods indicate that the proposed procedures perform as well as, or better than any currently known on these standard tests problems.

ISSN:0160-5682    

DOI:10.1057/jors.1985.9

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThis note considers the problem of cutting rectangular pieces from a single large rectangle so as to maximize the value of the pieces cut. A number of bounds that can be used in any tree search procedure for the problem are derived from a zero-one formulation of the problem. Computational results are presented.

ISSN:0160-5682    

DOI:10.1057/jors.1985.10

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor