Optimal control of a capacitated inventory system with multiple demand classes

This article studies the optimal control of a periodic‐review make‐to‐stock system with limited production capacity and multiple demand classes. In this system, a single product is produced to fulfill several classes of demands. The manager has to make the production and inventory allocation decisions. His objective is to minimize the expected total discounted cost. The production decision is made at the beginning of each period and determines the amount of products to be produced. The inventory allocation decision is made after receiving the random demands and determines the amount of demands to be satisfied. A modified base stock policy is shown to be optimal for production, and a multi‐level rationing policy is shown to be optimal for inventory allocation. Then a heuristic algorithm is proposed to approximate the optimal policy. The numerical studies show that the heuristic algorithm is very effective. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 43–58, 2011     

Designing acceptance sampling schemes for life testing with mixed censoring

Mixed censoring is useful extension of Type I and Type II censoring and combines some advantages of both types of censoring. This paper proposes a general Bayesian framework for designing a variable acceptance sampling scheme with mixed censoring. A general loss function which includes the sampling cost, the time‐consuming cost, the salvage value, and the decision loss is employed to determine the Bayes risk and the corresponding optimal sampling plan. An explicit expression of the Bayes risk is derived. The new model can easily be adapted to create life testing models for different distributions. Specifically, two commonly used distributions including the exponential distribution and the Weibull distribution are considered with a special decision loss function. We demonstrate that the proposed model is superior to models with Type I or Type II censoring. Numerical examples are reported to illustrate the effectiveness of the method proposed. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

Multiaction maintenance under markovian deterioration and incomplete state information

Much research been devoted to modeling the replacement problem under incomplete state information. Almost no work has been done on the maintenance problem under incomplete information with multiple maintenance actions that may not return the system to as good as new. We model this problem and derive structural results concerning the optimal maintenance policy. For the case where the effect of maintenance actions is state dependent, we give conditions under which the optimal policy is finitely computable. Where maintenance is state independent we show a specific structure, consisting of monotonic waiting times and constant maintenance actions, to be optimal.     

基于句子级BLEU指标挑选数据的半监督神经机器翻译

在单语语料的使用上,统计机器翻译可通过利用语言模型提高性能,而神经机器翻译很难通过这种方法有效利用单语语料.针对此问题,文中提出基于句子级双语评估替补(BLEU)指标挑选数据的半监督神经网络翻译模型.分别利用统计机器翻译和神经机器翻译模型对无标注数据生成候选翻译,然后通过句子级BLEU指标挑选单语候选翻译,加入到有标注的数据集中进行半监督联合训练.实验表明,文中方法能高效利用无标注的单语语料,在NIST汉英翻译任务上,相比仅使用精标的有标注数据单系统,文中方法BLEU值有所提升.     

On scheduling with ready-times,due-dates and vacations

A single machine sequencing problem is considered in which there are ready-time and due-date constraints on jobs and vacation constraints on the machine. Each vacation has fixed starting and finish time and no preemption is allowed for the jobs. The objective is to minimize maximum lateness. An intriguing feature of this formulation is that it allows sequencing in disconnected time windows. A relaxation of the problem is obtained by modeling the vacations as a set of jobs with flexible ready-times and artificial due-dates and a branch and bound algorithm is developed for the problem. In the algorithm, the search is not only guided by the bounds but also by a careful manipulation of the artificial due-dates. Consequently; while searching in the relaxed solution space, solutions of the original problem are implicitly enumerated. Computational results indicate that the algorithm can satisfactorily solve problems with multiple vacations.     

抗超高速撞击多层结构复合材料研究

本文介绍了抗超高速撞击多层结构复合材料的设计、制备和实验,并对结果进行了讨论,实验证明,以SiC陶瓷基复合材料为防护层、以空心微珠或多孔变密度复合材料为缓冲层、以编织物复合材料为结构层的多层结构复合材料,具有面密度低、抗撞击速度范围宽、抗撞击性能好的特点。     

最小自由能法计算烟火药剂热值

烟火药剂的热值计算在烟火研究领域有着重要的作用．本文根据最小自由能原理,通过一系列基本假设计算出了体系燃烧爆炸反应后的热值,计算结果与实验衡量数据相吻合,并且程序可通过进一步完善,扩展应用于非理想气体,提高计算精度．     

打赢现代应急动员“三大战役”——四川“5·12”抗震救灾动员回眸

“5·12”抗震救灾动员是新中国成立以来首次为应对重大突发事件,而在全国范围内实施的大规模局部动员和一省范围内实施的总动员,是一次真正意义上的应急动员。为有效应对这一重大自然灾害引发的原生危机、次生（衍生）危机和社会危机,此次应急动员活动围绕三大动员方向,科学调配社会力量资源,适时动态转换动员重心,打赢了现代应急动员“三大战役”,为未来应急动员的组织实施提供了宝贵经验和有益借鉴。     

浅谈二维条码在军品生产的应用

随着武器装备技术水平和复杂程度的提高,在生产过程和使用过程中需保存的信息量不断增大,这些信息对于控制军品质量、售后服务、维修保障等工作具有重要作用。本文着重介绍了二维条码的特点和优势,从软硬件要求、应用方法、存在问题及对策等方面,简要地提出了二维条码在军品生产中的作用和应用形式。     

争取最好前景 做好最坏准备——读两本抗美援朝战争史侧记

抗美援朝战争经验中总结的"争取和、准备打、军队只管打不管和"的14字方针体现了中共中央在处理和平与战争问题上的战略思维,不仅适用于朝鲜战争,更具有普遍意义,必须完整准确地理解其精神实质,把"争取最好前景"与"做好最坏准备"统一起来.