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391.
贮连续检测情形、定期检测情形、根除失效源意义下的可靠性增长试验建立了费用分析模型,着重对实际中经常采用的定期检测试验的费用问题进行了细致的分析,从理论上导出了定期检测中系统失效时停止运行和不停止运行的最佳检测周期。  相似文献   
392.
装备维修宏观调控指标体系研究   总被引:3,自引:0,他引:3  
在对大量历史数据的统计分析基础上 ,科学确定了全军装备维修宏观管理所需的调控指标 ,并建立了计量经济学模型和回归模型 ,为装备维修宏观调控提供了基本依据。  相似文献   
393.
In many practical situations of production scheduling, it is either necessary or recommended to group a large number of jobs into a relatively small number of batches. A decision needs to be made regarding both the batching (i.e., determining the number and the size of the batches) and the sequencing (of batches and of jobs within batches). A setup cost is incurred whenever a batch begins processing on a given machine. This paper focuses on batch scheduling of identical processing‐time jobs, and machine‐ and sequence‐independent setup times on an m‐machine flow‐shop. The objective is to find an allocation to batches and their schedule in order to minimize flow‐time. We introduce a surprising and nonintuitive solution for the problem. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004  相似文献   
394.
自动喷水灭火系统在我国一直存在质量不高、管理不当的现象,严重威胁人们的生命财产安全。产生这种现象的一个重要原因就在于投资者和业主不了解自动喷水灭火系统所能产生的经济效益,从而对设置该系统不够重视,甚至持反对的态度。针对这种情况,提出了一种定量评估设置自动喷水灭火系统的成本和效益的模型及具体计算方法,并结合工程实例验证了该模型的可行性。  相似文献   
395.
作业成本法在包装成本管理中的应用   总被引:2,自引:0,他引:2  
我国的市场竞争日趋激烈,产品的复杂程度越来越高,传统成本计算方法已无法满足对成本精确性的要求.鉴于作业成本法(ABC法)在成本管理领域中的日益普及,重点探讨ABC法在包装成本管理中的运用.通过对某企业包装成本进行实例计算和作业分析,说明应用ABC法可以得到相对准确的包装成本信息,并找出影响包装成本的主要因素及相应的解决方法,为包装成本管理提供了依据.  相似文献   
396.
We consider a two‐phase service queueing system with batch Poisson arrivals and server vacations denoted by MX/G1G2/1. The first phase service is an exhaustive or a gated bulk service, and the second phase is given individually to the members of a batch. By a reduction to an MX/G/1 vacation system and applying the level‐crossing method to a workload process with two types of vacations, we obtain the Laplace–Stieltjes transform of the sojourn time distribution in the MX/G1G2/1 with single or multiple vacations. The decomposition expression is derived for the Laplace–Stieltjes transform of the sojourn time distribution, and the first two moments of the sojourn time are provided. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
397.
    
We consider a generalized one‐dimensional bin‐packing model where the cost of a bin is a nondecreasing concave function of the utilization of the bin. Four popular heuristics from the literature of the classical bin‐packing problem are studied: First Fit (FF), Best Fit (BF), First Fit Decreasing (FFD), and Best Fit Decreasing (BFD). We analyze their worst‐case performances when they are applied to our model. The absolute worst‐case performance ratio of FF and BF is shown to be exactly 2, and that of FFD and BFD is shown to be exactly 1.5. Computational experiments are also conducted to test the performance of these heuristics. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006  相似文献   
398.
    
Fully sequential indifference‐zone selection procedures have been proposed in the simulation literature to select the system with the best mean performance from a group of simulated systems. However, the existing sequential indifference‐zone procedures allocate an equal number of samples to the two systems in comparison even if their variances are drastically different. In this paper we propose new fully sequential indifference‐zone procedures that allocate samples according to the variances. We show that the procedures work better than several existing sequential indifference‐zone procedures when variances of the systems are different. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006  相似文献   
399.
    
Additive convolution of unimodal and α‐unimodal random variables are known as an old classic problem which has attracted the attention of many authors in theory and applied fields. Another type of convolution, called multiplicative convolution, is rather younger. In this article, we first focus on this newer concept and obtain several useful results in which the most important ones is that if is logconcave then so are and for some suitable increasing functions ?. This result contains and as two more important special cases. Furthermore, one table including more applied distributions comparing logconcavity of f(x) and and two comprehensive implications charts are provided. Then, these fundamental results are applied to aging properties, existence of moments and several kinds of ordered random variables. Multiplicative strong unimodality in the discrete case is also introduced and its properties are investigated. In the second part of the article, some refinements are made for additive convolutions. A remaining open problem is completed and a conjecture concerning convolution of discrete α‐unimodal distributions is settled. Then, we shall show that an existing result regarding convolution of symmetric discrete unimodal distributions is not correct and an easy alternative proof is presented. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 109–123, 2016  相似文献   
400.
    
Motivated by the flow of products in the iron and steel industry, we study an identical and parallel machine scheduling problem with batch deliveries, where jobs finished on the parallel machines are delivered to customers in batches. Each delivery batch has a capacity and incurs a cost. The objective is to find a coordinated production and delivery schedule that minimizes the total flow time of jobs plus the total delivery cost. This problem is an extension of the problem considered by Hall and Potts, Ann Oper Res 135 (2005) 41–64, who studied a two‐machine problem with an unbounded number of transporters and unbounded delivery capacity. We first provide a dynamic programming algorithm to solve a special case with a given job assignment to the machines. A heuristic algorithm is then presented for the general problem, and its worst‐case performance ratio is analyzed. The computational results show that the heuristic algorithm can generate near‐optimal solutions. Finally, we offer a fully polynomial‐time approximation scheme for a fixed number of machines. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 492–502, 2016  相似文献   
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