ISSN:0160-5682    

DOI:10.1057/jors.1965.1

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractThis article attempts to place in focus the role of the Army Operational Research Establishment as interpreted against the broad and changing background of Army operational research.AORE is the oldest formally established operational research agency and, in this context, the pattern of evolution reflected by its programme of work is traced from World War II when problems were, in the main, concerned with getting the best out of existing weapons, equipment and the associated subsystems. Later the trend has moved towards systems analysis related to broad functional requirements and to the development of overall policies. The increasing complexity and cost of weapons and equipment and the growth of new but untried technologies add stimulus to studies of this nature and to the development of appropriate operational research techniques.

ISSN:0160-5682    

DOI:10.1057/jors.1965.2

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractThe arbitrary character of such concepts as“Discounted Present Worth”, which are often advocated as methods of assessing and comparing investment opportunities, is discussed in Part 1 of this paper. It is also pointed out that, by their nature, these concepts are not particularly well adapted to situations in which“risk”is an important factor. In order to develop a method in which a logical approach to risk can be adopted, an understanding of the basic problem of Decision Making under Uncertainty is required. An introduction to this subject forms Part 2 of this paper. In Part 3 the problem of Plant Investment under Risk is considered, and a rational approach to this is developed. The importance of the“portfolio”concept in such problems is particularly demonstrated.

ISSN:0160-5682    

DOI:10.1057/jors.1965.3

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractThe logistic model expects: If an item is told and heard in a set of people and periods under conditions of steady, pairing off, with equal opportunity, thenΔt=kptqt, i.e. increments in knowers are proportional to joint probabilities.Unequal opportunities result (among many causes) from“clique effects”where people communicate more within their daily circles of contacts (in homes, work, transit, eating and in leisure or other activities) than between such cliques.We hypothesized that if cliques are randomly overlapped in membership, then as clique size increases from 2 to allNpersons, the diffusion-retarding effect of clique barriers will tend to vanish.“Larger cliques accelerate diffusion.”Previous experiments confirmed this hypothesis up to 4-man cliques and contradicted it thereafter, as larger cliques exceeded logistic expectations, and did so systematically. This was due to a constraint of“seeking out non-knowers”which was eliminated in the present experiments.With three replications from a population of playing cards, simulating increasing sizes of cliques, the curves rose steadily towards the logistic as upper limit just as hypothesized. The parameterricmeasuring agreement of observed with expected increments rose from zero for the 2-man cliques up toric= 0·98 for theN-man clique-of-the-whole.From this and other experiments, we infer that logistic diffusion of items is likely to be approximated in so far as populations are homogeneous with very diversely overlapped cliques which are larger than pairs. As cliques enlarge, the diffusion curve approaches the simplest logistic model. At cliques of four persons, acceleration from“seeking non-knowers”offset deceleration from clique barriers.

ISSN:0160-5682    

DOI:10.1057/jors.1965.4

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractTwo studies are described dealing with the problem of hospital admission and duration of stay for maternity care. Maternity admissions and deliveries are shown to be strongly influenced by the general availability of hospital beds; duration of stay is not affected by bed scarcity. A statistical method of assessing the perinatal mortality risk of individual cases and selecting women for hospital care is outlined.

ISSN:0160-5682    

DOI:10.1057/jors.1965.5

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractTo date, no scientific method for the sizing of storage calorifiers has existed. This short paper outlines the analytical methods which were established to provide design criteria for the storage calorifiers serving hospital ward units. A full report of the survey which was carried out is contained in a paper entitled“A study of water consumption in ward units”.

ISSN:0160-5682    

DOI:10.1057/jors.1965.6

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractBy combining Roy's graph-theoretical interpretation of the problem of job scheduling on machines and some general results of his theory with the“branch-and-bound”method recently applied by Littleet al.to the travelling salesman problem an algorithm has been obtained for the exact solution of the scheduling problem in the case of three machines. The working of the algorithm has been illustrated by numerical examples and possibilities of further investigations have been indicated.

ISSN:0160-5682    

DOI:10.1057/jors.1965.7

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractIn the situation where a number of items must pass through a number of processes in the same order, it is suggested that the optimum (minimum total time) scheduling may be approximated by giving priority to items according to the extent to which process time increases with process number in order; this criterion is put in arithmetical form. This is confirmed by (a) a simple geometrical argument; (b) comparison with the known optimum schedules of a number of published three-process cases; (c) experiments on larger cases; it is not practical here to find the exact optimum.Methods are given for obtaining lower bounds which all scheduling times must equal or exceed; besides placing limits on the amount of effort to be expended, these bounds support the suggested approximate method.

ISSN:0160-5682    

DOI:10.1057/jors.1965.8

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1965.9

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1965.11

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor