Optimal inventory control policy for periodic‐review inventory systems with inventory‐level‐dependent demand

We consider a setting in which inventory plays both promotional and service roles; that is, higher inventories not only improve service levels but also stimulate demand by serving as a promotional tool (e.g., as the result of advertising effect by the enhanced product visibility). Specifically, we study the periodic‐review inventory systems in which the demand in each period is uncertain but increases with the inventory level. We investigate the multiperiod model with normal and expediting orders in each period, that is, any shortage will be met through emergency replenishment. Such a model takes the lost sales model as a special case. For the cases without and with fixed order costs, the optimal inventory replenishment policy is shown to be of the base‐stock type and of the (s,S) type, respectively. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012     

基于半马氏决策过程的电容器维修策略优化

针对电容器随机劣化失效的特点,采用半马氏决策过程解决其预防性维修方案设计和维修策略优化问题.在电容器随机劣化的Gaussian-Poisson模型基础上,以检测周期为优化变量,同时考虑预防性维修次数阈值的影响,建立电容器长期运行费用率优化模型.分析表明,对该型号电容器来说,预防性维修相比于事后修理更加有利于节省部件长期运行的费用率.     

Newsvendor problems with sequentially revealed demand information

This article analyzes a capacity/inventory planning problem with a one‐time uncertain demand. There is a long procurement leadtime, but as some partial demand information is revealed, the firm is allowed to cancel some of the original capacity reservation at a certain fee or sell off some inventory at a lower price. The problem can be viewed as a generalization of the classic newsvendor problem and can be found in many applications. One key observation of the analysis is that the dynamic programming formulation of the problem is closely related to a recursion that arises in the study of a far more complex system, a series inventory system with stochastic demand over an infinite horizon. Using this equivalence, we characterize the optimal policy and assess the value of the additional demand information. We also extend the analysis to a richer model of information. Here, demand is driven by an underlying Markov process, representing economic conditions, weather, market competition, and other environmental factors. Interestingly, under this more general model, the connection to the series inventory system is different. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 2012     

基于作战任务的多机种故障备件需求模型

通过分析战时故障备件的需求特点,对备件的工作时间进行讨论,改进了传统的单机故障备件需求模型。根据多机种协同作战任务的不同,引入备件工作运行比的概念,在考虑飞机是否战损的前提下,建立了基于作战任务的多机种故障备件需求模型。算例分析证明了模型的有效性。     

航空集群机载网络Failure-Oblivious路由策略

航空集群机载网络作为集群成员间信息交互的纽带,其路由策略性能优劣直接影响信息传输实时性与可靠性,从而制约网络化集群作战效能发挥.考虑到航空集群机载网络具有诸多不确定性,为应对路由失效以及尽可能避免路由更新,从路由选择算法的角度,在软件定义网络架构下提出Failure-Oblivious路由策略.与传统路由策略不同的是,...     

‘Clean’ bombs: Nuclear technology and nuclear strategy in the 1950s

The idea of ‘clean’ bombs, nuclear weapons with a reduced amount of radioactive fallout resulting from their fission part, has met much ridicule since its public inauguration in 1956. Many scholars have regarded the bombs as a propaganda tool, stopping short of analyzing their role in the transformative phase of US nuclear strategy in the 1950s. This paper reexamines the clean bomb episode through 1958, shedding light upon the dynamic relationship between the development of nuclear weapons technology and the evolution of nuclear strategy from massive retaliation to flexible response. It also discusses the mechanism and momentum of nuclear weapons technology innovation until the US suspended nuclear testing in late 1958.     

Russian Reactions to Reagan's ‘Maritime Strategy’

The US Navy's audacious Maritime Strategy of the 1980s is often credited with acting as a key catalyst to the demise of the USSR. In assessing the role of strategic missile submarine “bastions” in the country's overall military strategy, the authors are skeptical of the above thesis, explaining that Moscow actually viewed deployments of Tomahawk land-attack cruise missiles on to US submarines (versus direct threats against the Soviet Navy itself) as the most alarming threat. The authors concede that the arms race played a role in the collapse of the USSR, but deny a direct connection with Soviet naval development citing the relatively minor naval proportion of overall defense spending. For the difficulties facing the fleet at the end of the Cold War, they instead blame deep systemic problems internal to the Soviet Navy.     

Major Stepan Stebelski of the Ukrainian Insurgent Army: examples of insurgency leadership and tactics

This is a biographical analysis of Stepan Stebelski (‘Khrin’) and his time in the Ukrainian Insurgent Army. His military command is an example of classic insurgency tactics and strategies. He was trained in underground tactics before the Second World War, used his image very effectively during his time in the UPA, and used his knowledge of the terrain to become an exceptional enemy against Soviet and Polish authorities.     

The vanguard's dilemma: understanding and exploiting insurgent strategies

The purpose of this paper is to provide a better conceptualization of insurgent strategies. Specifically, I shall examine Che Guevara's ‘Foco’ theory of insurgency, as it is one of the most theoretically popular and most pervasive strategies of insurgency currently practiced throughout the world. After briefly examining the origins, objectives, and theoretical strengths of the Foco theory (also known as the Vanguard Theory), I will argue that Guevara's theory suffers from an internal tension that I term the ‘Vanguard's Dilemma’. The significance of this dilemma creates a tension within the Vanguard Theory that can be fatal for insurgents if properly exploited by counterinsurgent operations. This paper will examine in detail this dilemma and show how it can be exploited. Given that several insurgent groups within Iraq and Afghanistan currently adhere to the Vanguard Theory of insurgency, a proper understanding of this insurgent strategy is an essential first step in the long road towards confronting and winning asymmetrical conflicts.     

The strategic utility of New Zealand Special Forces

In 1955, the New Zealand government authorised the creation of a Special Forces unit to operate with British forces in Malaya to counter a communist-inspired guerrilla insurgency. Drawing upon the operational experiences of the New Zealand SAS largely taken from the Cold War period, and underpinned by Colin Gray's Special Forces essentials of ‘economy of force’ and ‘expansion of choice’, this article will show how New Zealand's SAS is now accepted not only as a respected and relevant part of the nation's military capability, but also empowers its political decision-makers with the confidence to take on significant, and at times difficult, strategic foreign-policy choices.