摘要:

AbstractMail-survey response rates and their prediction are important issues for researchers. The conceptual differences between industrial and most non-industrial populations raised doubt about the applicability of the Heberlein and Baumgartner model for the prediction of industrial mail-survey response rates. A test of their model using data from industrial mail-survey studies revealed a low level of predictive ability. A new model, based upon a linear logit specification and data from industrial populations, was developed and validated using a hold-out sample. The results suggested that the model based upon the new specification was superior to the simple linear alternative. The model identified a number of variables which were associated with response rates from industrial populations, and allows researchers to test and refine alternative survey designs.

ISSN:0160-5682    

DOI:10.1057/jors.1989.152

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper presents a microcomputerized simulation game designed as an analysis, experimentation and training tool in the field of intercity passenger-transportation planning and management. The simulation deals with different transportation modes and companies in a competitive environment, whether it be regulated or not. The background, philosophy and objectives of the game are discussed in relation to the intrinsic complexity of decision-making and the state of development of modelling in transportation.

ISSN:0160-5682    

DOI:10.1057/jors.1989.153

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe planning and design of computer networks give rise to many location problems. These may be split into those primarily concerned with placement of hardware and those with software. Here, a broad overview of location of software components (programs and data files) is given, together with a brief appraisal of the state-of-the-art for various problems.

ISSN:0160-5682    

DOI:10.1057/jors.1989.154

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn index fund is an investment vehicle which mimics a stock-market index and thus exhibits market risk only. Fund managers can passively invest in index funds and concentrate on actively managing the remainder of their funds. This paper looks in detail at the use of statistical selection methods in the construction of these funds. The measurement of the ability of these funds to track the underlying index is examined. Emphasis is placed on the relevance of the horizon of the investor to the choice of measure of tracking error. Four different methods of index-fund construction are described and applied to Japanese stock-market data. The tracking abilities of the constructed funds, both in and out of sample, are compared and contrasted.

ISSN:0160-5682    

DOI:10.1057/jors.1989.155

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper describes a case study on the logistics of replenishing a naval warship group. A discrete simulation model of the system was developed. A rule-based adviser was then embedded into the model, thus providing an intelligent decision-maker to automate the simulation model. The simulation methodology was later transformed from simple event-scheduling to the three-phase eLSE system, in preparation for future integration work. Some observations are made about the simulation methodologies used.

ISSN:0160-5682    

DOI:10.1057/jors.1989.156

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractConsider ak-out-of-nsystem where the lifetimes of the components are independent and identically distributed exponential (λ) random variables. Each component has its own repair facility, the repair times being independent and identically distributed exponential (μ) random variables, independent of the failure times. The mean operating time and mean repair time during the cycle between two successive breakdowns are found using renewal theory and the expression for the system availability. Using these, the mean first-passage times from any of the operating states of the system to the down state, and the mean first-passage times from any of the down states to the operating state are found recursively.

ISSN:0160-5682    

DOI:10.1057/jors.1989.157

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn interactive algorithm to solve multiple-objective non-linear programming (MONLP) problems is proposed. In each iteration of the proposed algorithm, the decision-maker is presented with a solution and a set of direction (trade-off) vectors indicating possible trade-offs. Using the decision-maker's preferred trade-off vector, a new current solution and the corresponding trade-off vectors are found. The proposed algorithm is illustrated with a numerical example of a replacement model. Finally, the method is compared with four other interactive multiple-objective algorithms.

ISSN:0160-5682    

DOI:10.1057/jors.1989.158

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper deals with the problem of finding the minimum finish-time schedule in a two-machine flowshop, where the processing times of jobs are linearly dependent on the job waiting-times. The problem is shown to be NP-hard. A heuristic algorithm is presented, and the worst-case bounds are derived for the different variations of the algorithm.

ISSN:0160-5682    

DOI:10.1057/jors.1989.159

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractFor farmers in the UK who use hosereel-raingun irrigation systems, irrigation scheduling requires that three questions be answered: (i) when should each field be irrigated; (ii) how much water should be applied; and (iii) which field should be irrigated first on a particular day? A mixed linear programme has been built to produce optimum irrigation schedules. The objective function maximizes the financial return from irrigation over the short term (typically 7 days). The constraints are equipment, labour and water availability. Use of the mixed linear programme is illustrated with a typical situation faced by a UK farmer.

ISSN:0160-5682    

DOI:10.1057/jors.1989.160

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractIn certain applications of linear programming, such as blending problems, there are constraints which place limits on ratios of linear combinations of the decision variables. These constraints can easily be linearized, but the values of the dual variables associated with them give the marginal cost associated with the linearized and not the original constraint. This note shows how the required marginal cost can be calculated by considering the problem as a special case of a more general one.

ISSN:0160-5682    

DOI:10.1057/jors.1989.161

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor