摘要:

AbstractMethods are developed for approximately characterizing the departure process from a single‐server queue and calculating approximate congestion measures for several single‐server queues in series. These methods are modifications of the previously described asymptotic method and stationary‐interval method for approximating a stochastic point process. The approximations are evaluated by comparing approximate congestion measures for queues in series with previous simulation re

ISSN:0028-1441    

DOI:10.1002/nav.3800310402

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

年代:1984

数据来源: WILEY

摘要:

AbstractThis article analyzes two general warranty policies involving an initial free replacement period, followed by apro rataperiod. We examine the short‐run total costs and longrun average costs under these policies. Formulas for both consumer costs and manufacturer profits under warranty are derived. We also study the expected number of purchases over the product life cycle under both policies. Bounds for the expected total costs and expected number of purchases are obtained for the case where the failure distribution of the item is new better than use

ISSN:0028-1441    

DOI:10.1002/nav.3800310403

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

年代:1984

数据来源: WILEY

摘要:

AbstractThis article considers combined continuous and discrete replacement with minimal repair at failure, in which a unit is replaced at time T or at number N of uses. Both optimal time T* and number N* to minimize the expected cost rate are discussed. They are found by unique solutions of equations when the hazard rates are monotonously increasing. A numerical example is given.

ISSN:0028-1441    

DOI:10.1002/nav.3800310404

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn this article, we are concerned with scheduling stochastic jobs in a flowshop with m machines and zero intermediate storage. We assume that there are n ‐ 2 identically distributed and 2 fast stochastic jobs. Roughly, the main result states that the makespan is stochastically minimized by placing one of the fast jobs first and the other las

ISSN:0028-1441    

DOI:10.1002/nav.3800310405

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

年代:1984

数据来源: WILEY

摘要:

AbstractIt is sometimes reasonable to assume that the lifetime distribution of an item belongs to a certain parametric family, and that actual parameter values depend upon the testing environment of the item. In the two‐parameter Weibull family setting, suppose both the shape and scale parameters are expressible as functions of the testing environment. For various models of functional dependency on environment, maximum likelihood methods are used to estimate characteristics of interest at specified environmental levels. The methodology presented handles exact, censored, and grouped data. A detailed accelerated life testing analysis of stress‐rupture data for Kevlar/epoxy composites is gi

ISSN:0028-1441    

DOI:10.1002/nav.3800310406

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

年代:1984

数据来源: WILEY

摘要:

AbstractFinite Markov processes are considered, with bidimensional state space, such that transitions from state (n,i) to state (m,j) are possible only ifm≤n+ 1. The analysis leads to efficient computational algorithms, to determine the stationary probability distribution, and moments of first passage time

ISSN:0028-1441    

DOI:10.1002/nav.3800310407

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn this article we address the question of developing deep cuts for disjunctive programs using rectilinear distance measures. The method is applied to linear complementarity problems where the matrixMneed not be copositive plus. Some modifications that are needed as a computational expediency are discussed. The computation results for matrixMof size up to 30 × 30 are discussed

ISSN:0028-1441    

DOI:10.1002/nav.3800310408

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

年代:1984

数据来源: WILEY

摘要:

AbstractSample sizes for tolerance limits are given on a normal distribution. β‐Expectation tolerance intervals are defined and constructed to control the proportion in each tail of the normal distribution. We also require with a high probability that the proportion in each tail is close to its corresponding expected coverage. Under these conditions. we dctcrniine a minimum sample size and its accompanying tolerance limits. Graphs of minimum sample sizes for the tolerance limits are provided. The computation for minimum samplc sizes is based on the bivariate noncentral t distribution. Examples are given to illustrate the use of the grap

ISSN:0028-1441    

DOI:10.1002/nav.3800310409

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

年代:1984

数据来源: WILEY

摘要:

AbstractThis article considers an inventory model with constant demand and stochastic lead times distributed over a finite range. A generalization of the EOQ formula with backorders is derived and ranges for the decision variables are obtained. The results are illustrated with the case of uniformly distributed lead time.

ISSN:0028-1441    

DOI:10.1002/nav.3800310410

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

年代:1984

数据来源: WILEY

摘要:

AbstractOne branch of the reliability literature is concerned with devising statistical procedures with various nonparametric “restricted family” model assumptions because of the potential improved operating characteristics of such procedures over totally nonparametric ones. In the single‐sample problem with unknown increasing failure rate (IFR) distributionF, (1) maximum‐likelihood estimators ofFhave been calculated, (2) upper or lower tolerance limits forFhave been determined, and (3) tests of the null hypothesis thatFis exponential have been constructed. Barlow and Campo proposed graphical methods for assessing goodness of fit to the IFR model when the validity of this assumption is unknown. This article proposes several analytic tests of the IFR null hypothesis based on the maximum distance and area between the cumulative hazard function and its greatest convex minorant (GCM), and the maximum distance and area between the total time on test statistic and its GCM. A table of critical points is provided to implement a specific test having good overall power pro

ISSN:0028-1441    

DOI:10.1002/nav.3800310411

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

年代:1984

数据来源: WILEY