Selecting T for a periodic review inventory model with staggered deliveries

Consider a single‐item, periodic review, infinite‐horizon, undiscounted, inventory model with stochastic demands, proportional holding and shortage costs, and full backlogging. Orders can arrive in every period, and the cost of receiving them is negligible (as in a JIT setting). Every T periods, one audits the current stock level and decides on deliveries for the next T periods, thus incurring a fixed audit cost and—when one schedules deliveries—a fixed order cost. The problem is to find a review period T and an ordering policy that satisfy the average cost criterion. The current article extends an earlier treatment of this problem, which assumed that the fixed order cost is automatically incurred once every T periods. We characterize an optimal ordering policy when T is fixed, prove that an optimal review period T** exists, and develop a global search algorithm for its computation. We also study the behavior of four approximations to T** based on the assumption that the fixed order cost is incurred during every cycle. Analytic results from a companion article (where μ/σ is large) and extensive computational experiments with normal and gamma demand test problems suggest these approximations and associated heuristic policies perform well when μ/σ ≥ 2. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 329–352, 2000     

The 1983 Nuclear Crisis – Lessons for Deterrence Theory and Practice

This article distills insights for the scholarship of deterrence by examining the 1983 nuclear crisis – the moment of maximum danger of the late Cold War. Important contributions notwithstanding, our understanding of this episode still has caveats, and a significant pool of theoretical lessons for strategic studies remain to be learned. Utilizing newly available sources, this article suggests an alternative interpretation of Soviet and US conduct. It argues that the then US deterrence strategy almost produced Soviet nuclear overreaction by nearly turning a NATO exercise into a prelude to a preventive Soviet attack. Building on historical findings, this article offers insights about a mechanism for deterrence effectiveness evaluation, recommends establishing a structure responsible for this endeavor, and introduces a new theoretical term to the strategic studies lexicon – a ‘culminating point of deterrence’.     

The 1907 Naval War Plans and the second Hague peace conference: A case of propaganda 1

The phenomenon of mutual sea denial had rendered offensive naval actions such as commercial blockade impossible in the narrow seas around Europe. Consequently, the First Sea Lord, Admiral Sir John Fisher, abandoned commercial blockade for the safer option of interdicting enemy commerce on the high seas where the Royal Navy could control communications. The proposal to extend immunity to all private property at sea at the 1907 Hague Conference threatened this strategy. As part of a wider campaign to convince the British establishment to oppose immunity, Fisher created the 1907 Naval War Plans to directly influence Cabinet decision-making. Fisher's close involvement in the creation of the ‘Plans’ indicates that they are an expression of Fisher's strategic vision. Moreover, Fisher's attempt to influence the Cabinet asks questions of the bureaucratic decision-making process within the British establishment before 1914.     

职校数学课堂“分层教学”的策略研究

职校的分层教学是根据职校教育的现状、针对不同层次中职学生的实际,在教学目标、内容、途径、方法上区别对待,使不同层次中职学生都能在其已有基础上很好发展的一种课堂教学策略。在职校数学课程改革理念的引领下,通过对学生自身状况的分析、做好中职学生的层次划分、不同备课目标的制定、不同课堂教学的设计、不同层次联系的布置、课后分层辅导的制定、评价等环节,更能展现因材施教的教学原则,对中职学生个性化教育有所帮助,同时,有利于培养中职学生的逻辑思维,改善当前数学课堂教学的情形,增强学生在数学中的应用能力,从而提高数学教学效果。     

搜索路径给定时的搜索对策问题及其应用

搜索路径给定时的最优搜索方案问题,也可以理解为是关于搜索者和目标的二人对策问题,主要讨论了当搜索路径给定时的单个搜索者和单个目标的搜索对策问题。首先根据问题的特点,利用动态规划和迭代的方法,确定关于目标逃逸路径混合策略的最优分区,证明该分区是多面体凸集;针对目标不同逃逸路径的分区,求出搜索者的最大期望收益,再将问题转化为二人有限零和对策,计算出搜索者的支付矩阵,确定最优搜索策略。最后结合海军护航行动,对我舰载直升机搜索小型海盗船进行分析和计算,说明搜索路径给定时的最优搜索对策对于双方的资源分配和提高搜索效率具有一定的应用价值。     

英语泛读易出现的问题及对策

针对大学英语泛读教学中易出现的问题,系统分析了产生这些问题的主观和客观原因,并提出了解决这些问题的具体办法--教师在泛读课上应把握各教学环节,以"参与者"的身份引导学生阅读,是提高学生阅读能力的重要途径.     

履带车辆下长坡液力辅助制动控制策略仿真研究

针对履带车辆下长坡制动过程中不同制动力的分配关系,在液力减速器和整车下坡动力学分析的基础上,研究了基于液力辅助制动的履带车辆下长坡制动控制策略,建立了基于SIMULINK的履带车辆整车动态仿真模型,对液力减速器的持续制动性能和控制策略的有效性进行了仿真．结果表明,车辆下坡持续制动时,适时应用液力减速器,能够有效分流整车制动功率,明显降低机械制动器的工作负荷,满足整车安全恒速下坡的要求．     

海上犯罪案件的特点及侦查方略研究

随着海洋经济的迅速发展,海上人、财、物的流动急剧增加,海上治安形势日趋复杂。海上抢劫、盗窃、偷渡及贩枪贩毒等犯罪活动呈多发态势,这严重破坏了海上的生产作业秩序,危害了海上治安秩序的稳定。研究海上犯罪案件的特,点,有助于公安边防部门采取有针对性的侦查方略,有力地打击海上犯罪,以创造安全、有序的海上治安环境。     

论边防行政复议存在的问题及对策

边防行政复议是规范边防行政执法和对边防行政执法相对人权益进行救济的重要途径。当前边防行政复议主要存在立法不完善、复议机构设置不完善、复议工作人员法律素质偏低、复议案件审查程序不严谨等方面的问题。加强和完善边防行政复议,主要应从立法、机构设置、转变观念等方面入手。     

基于全站仪最佳布站的调炮精度检测方法

针对目前缺少火炮调炮精度检测方法的现状,提出了一种基于全站仪最佳布站的调炮精度检测方法,建立了全站仪测量系统的数学模型,推导了调炮精度检测方法的解算公式,根据火炮调炮范围确定了调炮精度检测中的测量区域,得出全站仪测量系统对于整个测量区域的测量不确定度,结合某型火炮设计了画图法优化过程,得到全站仪测量系统的最佳测量布站位置。精度仿真试验表明,该方法可对调炮精度进行检测,使最佳布站测量系统的精度高于随机布站的精度。