Technical note: An improved range chart for normal and long‐tailed symmetrical distributions

The distribution of the range of a sample, even in the case of a normal distribution, is not symmetric. Shewhart's control chart for range and other approximations for range from skewed distributions and long‐tailed (leptokurtic) symmetrical distributions assume the distribution of range as symmetric and provide 3 sigma control limits. We provide accurate approximations for the R‐chart control limits for the leptokurtic symmetrical distributions, using a range quantile approximation (RQA) method and illustrate the use of the RQA method with a numerical example. As special cases, we provide constants for the R‐chart for the normal, logistic, and Laplace distributions. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

Technical note: Reexamination of all‐or‐none inspection policies in a supply chain with endogenous product quality

This note studies the optimal inspection policies in a supply chain in which a manufacturer purchases components from a supplier but has no direct control of component quality. The manufacturer uses an inspection policy and a damage cost sharing contract to encourage the supplier to improve the component quality. We find that all‐or‐none inspection policies are optimal for the manufacturer if the supplier's share of the damage cost is larger than a threshold; otherwise, the manufacturer should inspect a fraction of a batch. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

Scheduling and due‐date quotation in a make‐to‐order supply chain

We consider a manufacturer, served by a single supplier, who has to quote due dates to arriving customers in a make‐to‐order production environment. The manufacturer is penalized for long lead times and for missing due dates. To meet due dates, the manufacturer has to obtain components from a supplier. We model this manufacturer and supplier as a two‐machine flow shop, consider several variations of this problem, and design effective due‐date quotation and scheduling algorithms for centralized and decentralized versions of the model. We perform extensive computational testing to assess the effectiveness of our algorithms and to compare the centralized and decentralized models to quantify the value of centralized control in a make‐to‐order supply chain. Since complete information exchange and centralized control is not always practical or cost‐effective, we explore the value of partial information exchange for this system. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

基于复合等效可信度加权的Bayes融合评估方法

在小子样试验评估时,为避免大量先验信息湮没实际飞行试验的信息,融合先验补充样本时通常会进行数学相容性检验并加权.首先分析了小子样情形下直接根据数据计算数学相容性可能造成的不稳定性,为改善这种情况,根据不同试验类型的不同试验环境,对不同试验类型下的误差进行分析和折合,定义了物理等效可信度;并结合物理等效可信度和数学相容性检验,得到先验样本的复合等效可信度权重,基于正态逆伽玛分布计算了Bayes融合评估的后验结果;通过比较Bayes估计后验方差与不磁合先验信息的估计后验方差,根据先验信息参与融合后是否能减小后验方差来判断先验样本是否应该参与融合.理论分析和仿真说明,基于复合等效可信度的加权方法是合理的.     

DEA models for two‐stage processes: Game approach and efficiency decomposition

Data envelopment analysis (DEA) is a method for measuring the efficiency of peer decision making units (DMUs). This tool has been utilized by a number of authors to examine two‐stage processes, where all the outputs from the first stage are the only inputs to the second stage. The current article examines and extends these models using game theory concepts. The resulting models are linear, and imply an efficiency decomposition where the overall efficiency of the two‐stage process is a product of the efficiencies of the two individual stages. When there is only one intermediate measure connecting the two stages, both the noncooperative and centralized models yield the same results as applying the standard DEA model to the two stages separately. As a result, the efficiency decomposition is unique. While the noncooperative approach yields a unique efficiency decomposition under multiple intermediate measures, the centralized approach is likely to yield multiple decompositions. Models are developed to test whether the efficiency decomposition arising from the centralized approach is unique. The relations among the noncooperative, centralized, and standard DEA approaches are investigated. Two real world data sets and a randomly generated data set are used to demonstrate the models and verify our findings. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

基于HLA的电子战仿真测试与评估

针对电子战系统的特点,介绍了电子战系统开发与测试的一般过程。分析基于高层体系结构的电子战仿真测试与评估包括两个方面,HLA各组成部分性能以及电子战系统自身效能的测试与评估。在分析美国电子战仿真测试的基础上,将基于HLA的电子战系统应用于指挥自动化体系对抗仿真中,设计了对应的框架结构。分别对运行支撑系统KD-RTI和DMSORTI1.3v6在不同传输方式下的传输时延和丢包率进行了比较。进一步以信息的完备性为指标,对电子战系统的作战效能进行了评估。     

人工智能技术的军事应用边界研究

与国际上其他军事强国相比,我国军事智能化发展还处于起步和探索阶段.当前军事智能化发展呈现出技术增长点随机发散与关键技术领域不聚焦等特征,阻碍了人工智能技术在军事领域的应用.人工智能技术在军事应用中应本着"有所为有所不为"的原则.为了增强对"为军所用"人工智能核心技术的评价能力,推动高需求匹配度的核心技术发展,本文对军事...     

仿真在制导兵器试验与鉴定中的应用

制导兵器向信息化方向发展,对制导兵器试验与鉴定技术提出了新的要求.针对这些新要求,介绍了国外制导兵器仿真试验技术现状和方法,论述了仿真在制导兵器试验与鉴定中的作用,设计了制导兵器半实物仿真试验系统及其试验模式.得出结论认为,建立实际飞行试验与半实物仿真试验相结合的综合试验模式,是仿真技术在制导兵器试验与鉴定中应用的发展方向.     

多喷嘴超声速引射器压力匹配性能试验研究

建立了多喷嘴超声速引射器试验台,采用燃气作为一、二次流驱动工质对多喷嘴超声速引射器进行了试验研究,重点考察了引射器的压力匹配问题。试验结果表明:一次流总压越低,引射喷嘴出口压力越低,与二次流压力匹配越容易;二次流总压越低,保持压力匹配对引射器的要求越高;二次流总温对压力匹配基本无影响。     

超燃冲压发动机燃烧室构型优化的试验研究

在直连式超燃冲压发动机试验系统上,通过调节超燃冲压发动机燃烧室壁面扩张角和燃料喷注位置,对燃烧室构型优化进行了试验研究。为了提高试验效率,燃烧室形面调节采用正交试验设计方法进行组织,每个形面进行5种喷注位置的试验,每次试验通过文氏管调节3个当量比的燃料流量。利用试验数据构造燃烧室性能关于构型参数的响应面模型,可用于燃烧室构型优化。通过两次渐进优化获得了性能更优的燃烧室构型,并根据试验数据分析了各构型参数对燃烧室性能的影响,结果表明:优化构型燃烧室的推力增益比基准构型增大了10.4%;燃烧室性能受各构型参数的强烈耦合影响。