摘要:

AbstractA mathematical model describing the sortie of a single aircraft under enemy threats, attacking a single passive target, is developed. Emphasis is placed on the determination of the probabilities associated with the various events in the sortie. These probabilities are then used to derive appropriate measures of effectiveness. The optimum sortie time is analyzed.

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<127::AID-NAV3220360202>3.0.CO;2-5

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

年代:1989

数据来源: WILEY

摘要:

AbstractWith repeated firing, fatigue cracks are produced in a gun barrel, and the barrel is no longer useful when a crack reaches a critical size. The initial crack size and the critical crack size, as well as the number of firings producing the critical crack size, may be considered as random variables. Assuming a proportional damage model for crack growth, a method for estimating the critical crack size distribution is presented. From these results, an estimate of the barrel life, or the residual barrel life once a crack of a given size is measured, can be obtained.

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<139::AID-NAV3220360203>3.0.CO;2-Y

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

年代:1989

数据来源: WILEY

摘要:

AbstractFinite‐capacity queues arise naturally in many practical situations, notably in communications and manufacturing engineering. In this article, the matrix formalism of probability distributions of phase type is used to develop fast algorithms to compute various steady‐state distributions for the finite‐capacity PH/PH/1 queue. This algorithm is an important ingredient in solving nontraditional but significant design problems. Some of these are described as illustrative exa

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<147::AID-NAV3220360204>3.0.CO;2-U

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe DOD directs the usage of 10% of item cost as the cost of capital in the calculation of inventory holding costs. This 10% cost is not totally justified and a complete review must be accomplished to bring this factor to a meaningful and more useful value. The current logic supporting a 10% cost of capital results in a continuing perturbation which forces the Air Force to operate in a less than efficient mode when using the economic order quantity for consumable purchases.

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<167::AID-NAV3220360205>3.0.CO;2-L

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

年代:1989

数据来源: WILEY

摘要:

AbstractWe consider a multiechelon repairable‐item inventory system where several bases are supported by a central depot. Unlike METRIC‐based models, there are only a finite number of repairmen at each base and the depot, and the failure rates at the bases depend on the current number of items online. The principal objective of this article is to develop a quick and accurate approximation to the steady‐state distribution of this system. A secondary objective is to compare the solution of this system with a comparable METRIC sol

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<179::AID-NAV3220360206>3.0.CO;2-D

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

年代:1989

数据来源: WILEY

摘要:

AbstractDirichlet mixed models find wide application. Estimation is usually achieved through the method of moments. Here we present an iterative hybrid algorithm for obtaining the maximum likelihood estimate employing both modified Newton‐Raphson and E‐M methods. This successful MLE algorithm enables calculation of a jack‐knife MLE. Simulation comparison of the three estimates is provided. The MLE substantially improves upon the moments estimator particularly with increasing dimension. The jack‐knife MLE in turn offers dramatic improvement over

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<197::AID-NAV3220360207>3.0.CO;2-6

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe standard problem in sampling inspection is to consider plans with and without curtailment. Curtailment causes difficulty and authors rarely give exact results (i.e., exact OC and ASN functions) for curtailed procedures. In this article we regard curtailment as an inverse sampling procedure and use Dirichlet integrals to obtain exact formulas for the OC, the ASN, and also the variance of the number of observations required under three types of plans: no curtailment, semicurtailment (for rejection only) and two‐sided curtailment. Different sections of the article deal with the single sample, the two‐stage, and the multiple‐stage sampling problems. New tables for carrying out the single‐sample procedure are included in the article. The authors feel that this article presents new directions and new ways of dealing with problems associated with quality

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<215::AID-NAV3220360208>3.0.CO;2-S

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

年代:1989

数据来源: WILEY

ISSN:0894-069X    

DOI:10.1002/1520-6750(198904)36:2<::AID-NAV3220360201>3.0.CO;2-B

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

年代:1989

数据来源: WILEY