摘要:

AbstractA survey of the practitioner members of the United Kingdom Operational Research Society was conducted to identify current levels of MS/OR tool usage at the strategic level. In this paper details of the survey will be outlined, the framework of strategic tasks will be described, and the MS/OR tool usage results for these strategic tasks will be presented and discussed.

ISSN:0160-5682    

DOI:10.1057/jors.1995.148

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThe concept of sustainable yield, i.e. the fish catch that can be maintained in the long run from a fishery in a steady state, is widely used in fisheries management. In traditional methods of sustainable yield analysis, based on the Schaefer model of a fish stock, the age structure of the stock is ignored. Approaches based on the Beverton-Holt multicohort fish population model take account of age structure but assume that instantaneous natural and fishing mortality rates are constant throughout the year. Using a fish population model in which this assumption is not required, a mixed integer programming model is developed for the analysis of a multicohort single-species fishery in a steady state. This new method of sustainable yield analysis is demonstrated using data for the western mackerel fishery. Comparisons with results from other studies of this fishery are presented.

ISSN:0160-5682    

DOI:10.1057/jors.1995.149

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThis paper is concerned with the study of force deployment in a conventional theatre-level military engagement. First, it discusses some of the governing parameters that affect the modelling. A non-linear programming model is then developed to describe the combat dynamics. Sensitivity analysis on the optimal solution is also discussed. The merit of the model is demonstrated by applying the formulation to study the effect of various sustainment policies on the outcome of a battle.

ISSN:0160-5682    

DOI:10.1057/jors.1995.150

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractSugar cane harvesting consists of the following operations: cutting the cane, carrying it from the field to the processing plant and unloading it there. Before being harvested, the sugar cane is burnt and after burning it has to be processed within 15 days, otherwise the saccharose in it will gradually transform into ethylic alcohol and the cane will have to be discarded, because sugar cannot be extracted from it. In this paper, we present a simulation algorithm for scheduling the operations and for planning the resources available, in such a way that the time between the end of cane burning and the start of processing is minimized. This algorithm can provide the basis of a decision support system for minimizing the quantity of discarded cane and optimizing the utilization of resources.

ISSN:0160-5682    

DOI:10.1057/jors.1995.151

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThe National Health Service and the Social Services are engaged on a massive transfer of resources in which, wherever possible, care will be delivered to vulnerable patients in their own homes. This paper deals with two pilot medical practices in Rochdale. The needs of patients are considered on a subjective scale in five categories. It was confirmed that there was a consistency of subjective measurement between the nurses involved but there was no relation between these particular measures and the amount of nursing care being delivered. However, there was a strong relationship between age and the probability of being on the nursing care list, with a significant difference between the sexes. The model can lead to the identification of categories of patients who might have slipped through the net and also to estimates of the total home care nursing list in a practice.

ISSN:0160-5682    

DOI:10.1057/jors.1995.152

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractPort cities where marine cargo terminals are located are generally near urban areas characterized by high-congestion road traffic. Changes in cargo traffic volumes into a marine terminal, or in the surrounding traffic arteries, which carry this traffic, can significantly affect the terminal's operations. Conversely, activity at the terminal can have an impact on the traffic levels and congestion for a considerable distance from the terminal. This paper demonstrates a methodology useful for studying the impact of road traffic flows on marine container terminals located in highly congested areas. This model was developed at the request of the Virginia Center for World Trade and was used to answer three planning questions in the port of Hampton Roads, Virginia, USA-what would be the impact of: opening a new section of interstate highway, a projected doubling of container traffic at one terminal, and a daily unit train in the vicinity of another terminal. The problem was made more challenging by limited data-collection funds. None the less, the model was deemed valid by a panel of traffic experts and officials from several major state and private agencies involved in marine traffic management. The model results were subsequently a factor in two major decisions related to terminal management.

ISSN:0160-5682    

DOI:10.1057/jors.1995.153

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThis paper reports research on an estimator of bus driver duties. The estimator simulates rules in the manual scheduling process; it produces the number of duties likely to be required in a driver schedule. The development of this system involved a series of learning processes, concerning knowledge acquisition and the solution of real problems. The paper describes how the knowledge of scheduling is formulated and built into the estimator.

ISSN:0160-5682    

DOI:10.1057/jors.1995.154

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThis paper sets out a model that simultaneously determines insurers' satisficing compositions of their insurance and investment portfolios. This model can be explained as follows: different insurance lines and investments have different rates of return and different risks associated with those rates of return. Different insurers also have different, but satisfactory levels of return on equity and risk levels of violating the minimum requirement on cash and liquid assets. We propose a chance constrained programming approach to incorporate all of these factors in the portfolio analysis.

ISSN:0160-5682    

DOI:10.1057/jors.1995.155

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractWe present an interior Multiple Objective Linear Programming (MOLP) algorithm based on the path-following primal-dual algorithm. In contrast to the simplex algorithm, which generates a solution path on the exterior of the constraints polytope by following its vertices, the path-following primal-dual algorithm moves through the interior of the polytope. Interior algorithms lend themselves to modifications capable of addressing MOLP problems in a way that is quite different from current solution approaches. In addition, moving through the interior of the polytope results in a solution approach that is less sensitive to problem size than simplex-based MOLP algorithms. The modification of the interior single-objective algorithm to MOLP problems, as presented here, is accomplished by combining the step direction vectors generated by applying the single-objective algorithm to each of the cost vectors into a combined direction vector along which we step from the current iterate to the next iterate.

ISSN:0160-5682    

DOI:10.1057/jors.1995.156

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractWe consider a problem of sequencing a set of alternatives (i.e. manufacturing methods, job applicants or target journals) available for selection to complete a project. Associated with each alternative are the probability of successful completion, the completion time, and the reward obtained upon successfully completing the alternative. The optimal sequencing strategy that maximizes the expected present value of total rewards, is derived based on a simple ordering parameter. We further consider an extension in which one of the alternatives will not be available for selection if not selected by a certain time, and another extension in which the selection process is allowed only for a limited period of time. We propose solution strategies to the selection and sequencing problem under time constraints.

ISSN:0160-5682    

DOI:10.1057/jors.1995.157

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor