摘要:

ABSTRACTThe paper discusses the value of information when a number of independent sources provide information related to a common set of states of nature. The starting point is the information economic model of information structures. The model is augmented to represent independence of informational sources by means of orthogonality of the information structures.A new mathematical operator, orthogonal product, is defined and its properties are probed. It is shown that this operator maintains some mathematical properties such as closure, association, unity element, null element, and so forth. It is demonstrated how the orthogonal product represents the notion of multisource information.The paper proves that an orthogonal product is generally more informative than its multipliers, namely, if cost is not considered a constraining factor, then there is a nonnegative value to obtaining a second opinion. An appendix to the paper expands this result to a case of partially dependent signals. The paper concludes with a numerical example and a discussion of the model's applicability for practical problems such as cost estimates.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00265.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTDiscriminant analysis is relevant to business decision making in a variety of contexts, such as when one decides to make or buy a specified component, fund a venture project, or hire a particular person. Potential applications in artificial intelligence, particularly in the area of pattern recognition, have further underscored the importance of the field. A recent innovation in discriminant analysis is provided by special linear programming (LP) models, which offer attractive alternatives to classical statistical approaches. The scope of application in which discriminant analysis can be advantageously employed is broadened by the flexibility to tailor parameters in the LP approaches to reflect diverse goals and by the power to explore the sensitivity of these parameters. In spite of the promise of the LP formulations, however, limitations to their effectiveness have been uncovered in certain settings. A recent advance involving a normalization construct removes some of the limitations but entails solving the LP model twice (to allow for different signs of a normalization constant) and does not yield equivalent solutions for different rotations of the problem data. This paper introduces a new model and a new class of normalizations that remedy both remaining limitations, making it possible to take advantage of the modeling capabilities of the LP formulations without the attendant shortcomings encountered by earlier investigations. Our development shows by empirical testing and illustrative analysis that the quality of solutions from LP discriminant approaches is more favorable (relative to the classical model) than previously supposed.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00266.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThis paper presents a new integrative concept for job sequencing, dispatching, and lot sizing. The interrelation between these procedures and their impact on flow‐time performance is examined in a capacitated production environment. Generally, lot‐sizing decisions are made without regard to shop conditions and do not consider their impact on job sequencing procedures. The repetitive lots (RL) concept (developed and tested in this paper) attempts to integrate these decision processes.RL uses a number of features which have not been considered jointly in either the lot‐sizing or job‐dispatching/sequencing literature. These include operation batch sizes which vary by operation, transfer of work within the shop in quantities less than operation batch size, and the use of overlapped operations. A simulation model is used to analyze flow‐time characteristics in a hypothetical production system. Traditional measures of flow‐time performance are compared to a set of nontraditional measures which capture the interaction between lot sizing and the sequencing pro

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00267.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTConsumer choice among multiattributed products is modeled as a two‐stage process in which a conjunctive stage (that eliminates products with one or more “totally unacceptable” attribute levels) is followed by a compensatory stage (that trades off remaining products on multiple attributes). A self‐explicated preference measurement procedure based on the two‐stage model yielded a slightly larger predictive validity compared to conjoint

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00268.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTEach of the many two‐dimensional variations of the classical assignment problem has at least one counterpart in higher dimensions. This paper is a tutorial on these higher dimensional assignment models and their applications. It is a synthesis of a vast literature scattered throughout a great variety of journal articles and other miscellaneous sources.We have attempted to make the paper a complete bibliography with the emphasis on topics important to practitioners of decision sciences. These topics include original results by the authors, most notably, a polynomial solution approach for a class of multidimensional assignment problems which often arise in scheduling application

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00269.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTFour discriminant models were compared in a simulation study: Fisher's linear discriminant function [14], Smith's quadratic discriminant function [34], the logistic discriminant model, and a model based on linear programming [17]. The study was conducted to estimate expected rates of misclassification for these four procedures when observations were sampled from a variety of normal and nonnormal distributions. In contrast to previous research, data were taken from four types of Kurtotic population distributions. The results indicate the four discriminant procedures are robust toward data from many types of distributions. The misclassification rates for both the logistic discriminant model and the formulation based on linear programming consistently decreased as the kurtosis in the data increased. The decreases, however, were of small magnitude. None of these procedures yielded statistically significant lower rates of misclassification under nonnormality. The quadratic discriminant function produced significantly lower error rates when the variances across groups were heterogeneous.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00270.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTAs a method of solving multiple‐criteria decision making problems with a single quantitative objective and multiple qualitative objectives, the post‐model analysis (PMA) approach is proposed. The essence of PMA is to support the trade‐offs between a quantitative objective and multiple qualitative objectives so that the decision maker can find a perceived most preferred nondominated solution. To this end, the optimal solution of a quantitative model is found first, without regard for qualitative factors. The solution is then evaluated in terms of qualitative objectives. When the initial quantitatively optimal solution is adjusted to allow improvement of qualitative goals, opportunity costs of achieving qualitative goals are incurred. In this process, an expert system and/or graphical display can be used. PMA therefore provides a way to incorporate quantitative models into knowledge‐based expert

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00271.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThis paper presents a tractable set of integer programming models for the days‐off scheduling of a mix of full‐ and part‐time employees working α to β days/week (cycle) in a multiple‐objective, multiple‐location environment. Previous models were formulated to specifically schedule part‐time employees working either two or three days per week. These models were intractable because they required complete employee schedule information. The new models are deemed implicit optimal since they are required to supply only essential information. While the number of variables in previous models is an exponential increasing function of β‐α, the size of three of the new models is independent of α and β.The first three models developed here (as in [18]) deal with the trade‐offs between idle time, the number of employees required to work at multiple “locations,” and the size of the total labor pool. The inherent flexibility of the implicit modeling approach is illustrated by the presentation of various modifications of the basic models. These modifications permit the use of preference weights on the number of employee work days/week (cycle) or the minimization of payroll costs where differential pay rates exist. These latter models may also be formulated such that idle time is ignored, constrained or minimized.The execution time for the implicit models (on a CDC CYBER 730 computer with commercially available software) averaged well under five seconds on 1200 trial problems for the type of application considered in [18]. A solution was obtained in less than 46 seconds of CPU time for a trial problem which would have required over 1.4 million integer variables with previous models.The availability of optimal solutions was invaluable in the development of two heuristics designed to deal with the trade‐offs of [16]. In an experimental analysis a previous heuristic produced results which averaged from 74 to 508 percent above optimum across six experimental conditions. The comparable new heuristic produced results which averaged from 3 to 8 percent above optimum for the same experimental conditions.The paper concludes by developing a framework to integrate the results of this research with the tour scheduling problem and by identifying several other

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00272.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThe matched‐pairs methodology is becoming increasingly popular as a means of controlling extraneous factors in business research. This paper develops discriminant procedures for matched data and examines the properties of these methods. Data from a recent study by Hunt [14] on the determinants of inventory method choice are used to contrast the performance of the different methods. While all of the methods yield the same set of discriminating variables, those procedures that allow for the dependence among observations within a pair provide greater classificatory power than traditional multivariate technique

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00273.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1988.tb00274.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY