Optimal and asymptotically optimal policies for assemble‐to‐order n‐ and W‐systems

We consider two specially structured assemble‐to‐order (ATO) systems—the N‐ and W‐systems—under continuous review, stochastic demand, and nonidentical component replenishment leadtimes. Using a hybrid approach that combines sample‐path analysis, linear programming, and the tower property of conditional expectation, we characterize the optimal component replenishment policy and common‐component allocation rule, present comparative statics of the optimal policy parameters, and show that some commonly used heuristic policies can lead to significant optimality loss. The optimality results require certain symmetry in the cost parameters. In the absence of this symmetry, we show that, for systems with high demand volume, the asymptotically optimal policy has essentially the same structure; otherwise, the optimal policies have no clear structure. For these latter systems, we develop heuristic policies and show their effectiveness. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 62: 617–645, 2015     

Auctions in the post‐change‐order period

A change order is frequently initiated by either the supplier or the buyer, especially when the contract is long‐term or when the contractual design is complex. In response to a change order, the buyer can enter a bargaining process to negotiate a new price. If the bargaining fails, she pays a cancellation fee (or penalty) and opens an auction. We call this process the sequential bargaining‐auction (BA). At the time of bargaining, the buyer is uncertain as to whether the bargained price is set to her advantage; indeed, she might, or might not, obtain a better price in the new auction. To overcome these difficulties, we propose a new change‐order‐handling mechanism by which the buyer has an option to change the contractual supplier after bargaining ends with a bargained price. We call this the option mechanism. By this mechanism, the privilege of selling products or services is transferred to a new supplier if the buyer exercises the option. To exercise the option, the buyer pays a prespecified cash payment, which we call the switch price, to the original supplier. If the option is not exercised, the bargained price remains in effect. When a switch price is proposed by the buyer, the supplier decides whether or not to accept it. If the supplier accepts it, the buyer opens an auction. The option is exercised when there is a winner in the auction. This article shows how, under the option mechanism, the optimal switch price and the optimal reserve price are determined. Compared to the sequential BA, both the buyer and the supplier benefit. Additionally, the option mechanism coordinates the supply chain consisting of the two parties. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 248–265, 2015     

基于“招标—投标”策略的舰艇编队协同反导优化

针对舰艇编队协同防空反导的作战过程,以缩短舰艇编队协同反导的整体拦截时间、降低反导资源的消耗为目标,构建了一种"招标—投标"策略的舰艇编队协同反导优化模型。该模型利用模糊数学和动态规划相结合的优化技术,在单个作战单元需要编队内其他作战单元协同反导的情况下,运用"招标—投标"策略建立满足反导策略的决策方案,能实时、动态的调整舰艇编队整体协同反导策略。     

滤波器阶数对导航接收机时域抗干扰的影响分析

滤波器阶数是影响卫星导航接收机时域自适应抗干扰性能和计算复杂度的核心参数。为了解决当前阶数选取严重依赖工程经验而影响分析不足的问题,分析了滤波器阶数对导航接收机时域自适应抗干扰性能的影响,可为导航接收机低复杂度时域抗干扰的研究提供理论支撑。该分析面向不同干扰环境,分别以滤波器幅频响应和信号载噪比为评估指标,并通过仿真实验和实测对传统最小均方算法和改进型最小均方算法进行验证,提出了一种基于数字滤波器设计的自适应最优滤波器阶数的设计方法。实验数据分析表明,通过适当提升滤波器长度,可以有效提升时域自适应滤波器的抗干扰性能;在实际应用中,可根据实际抗干扰需求,对滤波器阶数进行优化设计。     

效率、公平与公共政策

效率是社会经济发展的重要保证,而公平是衡量人类文明的重要尺度,是维护社会稳定的价值基础。效率与公平是辩证的对立统一,既有矛盾性又有统一性。公共政策的关键就是要协调与整合二者之间的关系,确保既能提高经济效率,又能实现社会公平——借助市场机制达到资源的有效配置,以提高效率;依靠社会主义制度解决财富分配不公,以彰显公平。将效率与公平完美地结合于公共政策之中,是社会主义优越性的充分体现。     

物理弱间断线上Ⅲ型斜交裂纹高阶渐近场

针对功能梯度材料层/均匀材料基体的物理弱间断线上斜交裂纹,通过分离变量和级数展开法构造位移函数,求得了裂纹尖端高阶渐近场。其界面裂纹尖端高阶渐近应力场具有与均匀材料相同的r-1/2的奇异性。由高阶项的表达式可知：材料非均匀性对应力场有显著影响。数学上,该解为此类问题的特征函数,能够描述此类材料各种含裂纹结构的整个应力场和位移场,当非均匀参数为零时,它可以退化到均匀材料反平面裂纹问题经典的W il-liam s解。     

边防武警执行命令行为的性质定位

边防武警具有军人和警察的双重属性,因此,其执行命令行为在性质上不同于普通的军事命令,而体现出一定的行政性特征。边防武警执行命令行为的性质定位直接关系到其执行多样化军事任务中各项行为的法律后果,具有重要的理论意义和司法实践意义。     

消防与保险互动机制研究

从分析消防和保险合作发展的历史、合作过程中存在的问题入手,探讨了新形势下消防与保险合作的机制,并从五个方面提出了消防和保险具体合作的方法和步骤,为今后消防和保险的合作提供了建设性的意见,也为消防工作今后的发展提供了新的思路。     

从部队视角看公安现役院校发展之路

公安现役院校是培养公安现役部队各类人才的重要基地,要走出一条符合时代特点和适应形势任务需要的科学发展之路,必须以科学发展观为指导,坚持与时俱进,在把握职责使命上要有新思路,在创新发展模式上要有新理念,在解决突出问题上要有新进展,从而有效提升教学质量和办学水平。     

论公安边防部队党组织建设中的“一单三制”制度

为解决部分党员领导干部不认真过双重组织生活的问题,上海边防总队确立了发放组织生活通知单和组织生活公示制、报告制、通报制,这对于党员领导干部过好组织生活起到了很好的规范作用。严格落实"一单三制"制度,需要把握好三个环节:一要筑牢思想基础,增强落实制度的责任感;二要强化管理监督,提升落实制度的严肃性;三要建立配套制度,提高制度落实的规范性。