摘要:

AbstractAn implicit enumeration algorithm is developed to determine the set of efficient points in zero‐one multiple criteria problems. The algorithm is specialized for the solution of a particular class of facility location problems. The procedure is complemented with the use of the utility function of the decision maker to identify a subset of efficient point candidates for the final selection. Computational results are provided and discusse

ISSN:0028-1441    

DOI:10.1002/nav.3800290202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractSuppose one object is hidden in thek‐th ofnboxes with probabilityp(k). The boxes are to be searched sequentially. Associated with thej‐th search of boxkis a costc(j,k) and a conditional probabilityq(j,k) that the firstj‐ 1 searches of boxkare unsuccessful while thej‐th search is successful given that the object is hidden in boxk.The problem is to maximize the probability that we find the object if we are not allowed to offer more thanLfor the search. We prove the existence of an optimal allocation of the search effortLand state an algorithm for the construction of an optimal allocation. Finally, we discuss some problems concerning the complexity of our

ISSN:0028-1441    

DOI:10.1002/nav.3800290203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThe problem of assigning computer program modules to functionally similar processors in a distributed computer network is investigated. The modules of a program must be assigned among processors in such a way as to minimize interprocessor communication while taking advantage of affinities of certain modules to particular processors. This problem is formulated as a zero‐one quadratic programming problem, but is more conveniently modeled as a directed acyclic search graph. The model is developed and a backward shortest path labeling algorithm is given that produces an assignment of program modules to processors. A non‐backtracking branch‐and‐bound algorithm is described that uses a local neighborhood search at each stage of the searc

ISSN:0028-1441    

DOI:10.1002/nav.3800290204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractPosition finding has historically been carried out by calculating the coordinates of the mean position via a least‐squares procedure based on the distance of the position from several direction lines. It has been suggested that the least‐squares procedure assigns too much weight to outliers among the set of direction lines, outliers which may actually be associated with objects other than the one being located. In this paper, a method of using least‐absolute deviations, which yields a more outlier‐resistant median estimate of the position instead of the least‐squares mean estimate, is

ISSN:0028-1441    

DOI:10.1002/nav.3800290205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractAn important class of network flow problems is that class for which the objective is to minimize the cost of the most expensive unit of flow while obtaining a desired total flow through the network. Two special cases of this problem have been solved, namely, the bottleneck assignment problem and time‐minimizing transportation problem. This paper addresses the more general case which we shall refer to as the time‐minimizing network flow problem. Associated with each arc is an arc capacity (static) and a transferral time. The objective is to find a maximal flow for which the length (in time) of the longest path carrying flow is minimized. The character of the problem is discussed and a solution algorithm is presen

ISSN:0028-1441    

DOI:10.1002/nav.3800290206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractTransportation problems with uncertain demands are useful applied models themselves, and also they represent in a formal way the problem of estimating demands for use in deterministic models. We consider the effects of using a small, aggregate model of this type in place of a larger, more detailed one. Formulation of the aggregate objective function turns out to depend on how one chooses to use (disaggregate) the solution; several alternative methods are examined. Bounds are derived on the error induced by the approximation, thus facilitating comparison of alternative aggregations. We also consider the problem of estimating demands for an aggregate‐level deterministic problem. In a specific sense, it is oftennotthe case (as one might expect) that such aggregate demands are easier to estimate than the detailed demands. This is because aggregation and centralization are not the same thin

ISSN:0028-1441    

DOI:10.1002/nav.3800290207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper studies certain “second order” parametric relations in capacitated transportation problems. These relations concern the question of what happens to the effect of a parameter (first derivative) as another parameter is varied. These relationships have been found quite useful in the solution of many types of facility location and capacity expansion problems. The paper presents several results on the parametric behavior of the dual multipliers from which second order parametric relations can be deri

ISSN:0028-1441    

DOI:10.1002/nav.3800290208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThe joint problems of determining the optimal plant locationandoptimal input mix and plant size are addressed. The interrelationship between input substitutability and plant location is stressed. Conditions under which the location problem can be separated from the determination of the optimal input mix are developed for a number of problem variations. The stability of the optimal location in the face of changes in problem parameters is also discussed. It is demonstrated that consideration of input substitutability often makes the resulting problem no more difficult to solve than problem formulations in which the inherent input substitutability is ignored.

ISSN:0028-1441    

DOI:10.1002/nav.3800290209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractSimple direct smoothing formulas are derived for updating coefficient estimates and forecasts in a discounted least squares model. These formulas are the natural extensions of R. G. Brown's well‐known smoothing formulas to a general econometric setting with arbitrary explanatory time series. The recursive updating process and its forecast error properties are illustrated via a simple, yet realistic numerical exampl

ISSN:0028-1441    

DOI:10.1002/nav.3800290210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper analyzes the problem of determining desirable spares inventory levels for repairable items with dependent repair times. The problem is important for repairable products such as aircraft engines which can have very large investment in spares inventory levels. While existing models can be used to determine optimal inventory spares levels when repair times are independent, the practical considerations of limited repair shop capacity and prioritized shop dispatching rules combine to make repair times not independent of one another. In this research a simulation model of a limited capacity repair facility with prioritized scheduling is used to explore a variety of heuristic approaches to the spares stocking decision. The heuristics are also compared with use of a model requiring independent repair times (even though that assumption is not valid here). The results show that even when repair time dependencies are present, the performance of a model which assumes independent repair times is quite good.

ISSN:0028-1441    

DOI:10.1002/nav.3800290211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY