Analysis of a two-component series system with a geometric process model

In this article, a geometric process model is introduced for the analysis of a two-component series system with one repairman. For each component, the successive operating times form a decreasing geometric process with exponential distribution, whereas the consecutive repair times constitute an increasing geometric process with exponential distribution, but the replacement times form a renewal process with exponential distribution. By introducing two supplementary variables, a set of partial differential equations is derived. These equations can be solved analytically or numerically. Further, the availability and the rate of occurrence of failure of the system are also determined. © 1996 John Wiley & Sons, Inc.     

射频识别系统的多目标识别-反碰撞算法

对多目标识别技术的二进制搜索算法、时隙ALOHA算法进行了剖析,并对ALOHA算法用概率论和数理统计的方法进行了深入的理论分析,得出要根据所设计的射频识别系统的特点合理采用各种算法方可得到良好的效果.该算法的实现对提高高速公路上自动收费系统、人员和物流管理等各领域的工作效率具有一定的指导意义.     

用科学发展观指导扎实有效地开展政治工作

科学发展观是加强和改进政治工作的重要指导方针。更加有力、更加扎实、更加富有成效地开展政治工作,必须牢固确立以科学发展观为指导的理念,切实理清工作思路,努力掌握科学方法,不断提高能力素质。     

牢固树立科学人才观——学习胡锦涛主席关于科学人才观的重要论述

科学人才观是做好人才工作,落实人才强军战略的思想基础。全面理解和践行科学人才观,一要牢固树立人才资源是第一资源、人人都可以成才、以人为本的观念;二要始终坚持党管人才原则,加强各级党委对人才工作的领导;三要构建与科学人才观相适应的军事人才激励机制。     

牢固树立和认真落实科学发展观推动部队思想政治建设创新发展

坚持用科学发展观统领部队思想政治建设创新发展,一要抓好用党的创新理论武装官兵这一基础性工程,兴起学习贯彻科学发展观热潮;二要紧贴时代和实践的新发展,提升思想政治建设的起点和标准;三要着眼部队全面建设和可持续发展要求,不断提高基层建设质量;四要加大组织指导力度,促进思想政治建设各项任务的有效落实。     

努力做社会主义荣辱观的模范实践者

社会主义荣辱观的提出,为构建和谐社会、推进思想道德建设提供了根本遵循,明确了当代中国最基本价值导向和行为准则。我们要紧密结合部队建设实际,增强践行“八荣八耻”的自觉性和坚定性,努力做社会主义荣辱观的模范实践者。     

推进军事学研究生教育科学发展

推进军事学研究生教育科学发展,必须贯彻落实科学发展观,坚持以人为本,树立发展的质量观、特色的质量观、全面的质量观;坚持协调发展,统筹数量规模与质量效益的关系、学术型标准与应用型标准的关系、共性要求与个性发展的关系;坚持固本强基,加强学科专业建设、导师队伍建设、政策制度建设,为研究生教育的可持续发展提供强大动力。     

Integrating decisions with advance supply information in an assemble-to-order system

We study a periodic-review assemble-to-order (ATO) system with multiple components and multiple products, in which the inventory replenishment for each component follows an independent base-stock policy and stochastic product demands are satisfied according to a First-Come-First-Served rule. We assume that the replenishment for various component suffers from lead time uncertainty. However, the decision maker has the so-called advance supply information (ASI) associated with the lead times and thus can take advantage of the information for system optimization. We propose a multistage stochastic integer program that incorporates ASI to address the joint optimization of inventory replenishment and component allocation. The optimal base-stock policy for the inventory replenishment is determined using the sample average approximation algorithm. Also, we provide a modified order-based component allocation (MOBCA) heuristic for the component allocation. We additionally consider a special case of the variable lead times where the resulting two-stage stochastic programming model can be characterized as a single-scenario case of the proposed multistage model. We carry out extensive computational studies to quantify the benefits of integrating ASI into joint optimization and to explore the possibility of employing the two-stage model as a relatively efficient approximation scheme for the multistage model.     

Inventory policies with quantized ordering

This article studies (nQ, r) inventory policies, under which the order quantity is restricted to be an integer multiple of a base lot size Q. Both Q and r are decision variables. Assuming the one-period expected holding and backorder cost function is unimodal, we develop an efficient algorithm to compute the optimal Q and r. The algorithm is facilitated by simple observations about the cost function and by tight upper bounds on the optimal Q. The total number of elementary operations required by the algorithm is linear in these upper bounds. By using the algorithm, we compare the performance of the optimal (nQ, r) policy with that of the optimal (s, S) policy through a numerical study, and our results show that the difference between them is small. Further analysis of the model shows that the cost performance of an (nQ, r) policy is insensitive to the choice of Q. These results establish that (nQ, r) models are potentially useful in many settings where quantized ordering is beneficial.     

Optimal allocation of minimal repairs in parallel and series systems

In reliability engineering, the concept of minimal repair describes that the repair brings the failed unit (eg, system or component) to the situation which is same as it was just before the failure. With the help of the well‐known Gamma‐Poisson relationship, this paper investigates optimal allocation strategies of minimal repairs for parallel and series systems through implementing stochastic comparisons of various allocation policies in terms of the hazard rate, the reversed hazard rate, and the likelihood ratio orderings. Numerical examples are presented to illustrate these findings as well. These results not only strengthen and generalize some known ones in the seminal work of Shaked and Shanthikumar, but also solve the open problems proposed by Chahkandi et al.'s study and Arriaza et al.'s study.