Dynamic coordination of production planning and sales admission control in the presence of a spot market

We consider the decision‐making problem of dynamically scheduling the production of a single make‐to stock (MTS) product in connection with the product's concurrent sales in a spot market and a long‐term supply channel. The spot market is run by a business to business (B2B) online exchange, whereas the long‐term channel is established by a structured contract. The product's price in the spot market is exogenous, evolves as a continuous time Markov chain, and affects demand, which arrives sequentially as a Markov‐modulated Poisson process (MMPP). The manufacturer is obliged to fulfill demand in the long‐term channel, but is able to rein in sales in the spot market. This is a significant strategic decision for a manufacturer in entering a favorable contract. The profitability of the contract must be evaluated by optimal performance. The current problem, therefore, arises as a prerequisite to exploring contracting strategies. We reveal that the optimal strategy of coordinating production and sales is structured by the spot price dependent on the base stock and sell‐down thresholds. Moreover, we can exploit the structural properties of the optimal strategy to conceive an efficient algorithm. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

Optimal control of a production‐inventory system with both backorders and lost sales

We consider the optimal control of a production inventory‐system with a single product and two customer classes where items are produced one unit at a time. Upon arrival, customer orders can be fulfilled from existing inventory, if there is any, backordered, or rejected. The two classes are differentiated by their backorder and lost sales costs. At each decision epoch, we must determine whether or not to produce an item and if so, whether to use this item to increase inventory or to reduce backlog. At each decision epoch, we must also determine whether or not to satisfy demand from a particular class (should one arise), backorder it, or reject it. In doing so, we must balance inventory holding costs against the costs of backordering and lost sales. We formulate the problem as a Markov decision process and use it to characterize the structure of the optimal policy. We show that the optimal policy can be described by three state‐dependent thresholds: a production base‐stock level and two order‐admission levels, one for each class. The production base‐stock level determines when production takes place and how to allocate items that are produced. This base‐stock level also determines when orders from the class with the lower shortage costs (Class 2) are backordered and not fulfilled from inventory. The order‐admission levels determine when orders should be rejected. We show that the threshold levels are monotonic (either nonincreasing or nondecreasing) in the backorder level of Class 2. We also characterize analytically the sensitivity of these thresholds to the various cost parameters. Using numerical results, we compare the performance of the optimal policy against several heuristics and show that those that do not allow for the possibility of both backordering and rejecting orders can perform poorly.© 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010     

基于单片机的远程光纤通信在点对点安全验证系统上的应用

现有的点对点安全验证系统都是基于电缆连接实现系统信息传输的。电缆传输信号存在传输衰减大、抗干扰能力差、在雷暴天气易发生事故等缺点。通过将基于单片机89C2051的远程光纤通信应用到现有设备来改进控制信号的传输模式,将电信号转换为光信号,在数据传输中使用传输同步码加密、数据包CRC校验、串行数据编码以及光纤连通性定时自动监测等技术,可以从物理信号传输到数据接收处理的整个过程中保证系统的安全性和可靠性;同时,通过光纤通信方案,也能节省系统构建和维护的经费。     

对提高武警部队遂行多样化任务通信保障能力的思考

通信保障能力是武警部队战斗力的重要方面。近年来,武警部队担负的多样化任务日趋增多,呈现出许多新特点,对通信保障能力提出了新的更高要求,加强通信保障能力意义重大。本文从武警部队通信保障能力的现状入手,分析了当前通信保障能力的基本情况和存在不足,并就如何适应形势发展需要,提高遂行多样化任务的通信保障能力进行了思考。     

科技创新引领下的武警部队现代化装备建设发展思路与策略

推进武警部队现代化装备建设跨越发展,需要认清现状、更新观念、明确目标,确立没有科技创新就没有真正意义上的现代化装备建设的观念。武警装备科技创新,应在注重装备理论研究、加强非致命武器研发、拓展特种器材研制上实现新的突破和跨越;要在创新科技人才建设机制、完善装备科研管理机制、建立装备研发保障机制上增强科技创新能力,发挥科技创新引领的作用。     

试论应急管理体系的财政支撑

从2003年的“非典”开始,我国逐步建立起了一套应急管理体系,在南方冰雪灾害、汶川地震以及今年的玉树地震和南方水灾等抗震救灾工作中发挥作用并不断完善。财政支撑在应急管理体系中有着至关重要的作用。对目前我国应急财政管理现状进行分析,结合对外国应急管理体系先进做法的借鉴,提出了对建立健全应急财政支撑体系的政策建议。     

反证法的历史沿革

反证法是数学中常用的一种证明方法。由于逻辑学中也存在同样的相关概念 ,所以分清反证法、归谬法以及反驳和证明之间的细微差别和联系 ,是很有必要的 ,并指出反证法不但是最重要的证明方法 ,而且同其它的证明方法一样也是进行科学积累和发现的源泉。     

空地作战地空导弹射击的一种仿真模型研究

空地作战仿真研究中,对地空导弹射击的仿真是非常重要的一环。给出了一种地空导弹对空中目标射击的建模方法,该方法对建立战役、战术级突防或防空仿真试验系统具有较强的实用性和适用性。     

武器系统经济性参数的支持向量机方法分析

采用一种基于支持向量机的武器系统费用分析方法.计算结果表明,这种方法有效解决了参数法对样本量要求较高以及对非线性问题处理能力较弱等问题.与传统方法相比较,有更好的拟合精度和泛化能力,因而该方法可以作为研究此类问题的新途径.     

基于DW+OLAP+DM的器材保障决策支持系统设计

针对我军当前器材保障状况,阐述了基于数据仓库、联机分析处理和数据挖掘技术的决策支持系统的设计方案和开发理论。通过分析器材保障决策支持的特点,确定了器材保障决策支持系统的需求。具体论述了器材保障决策支持系统的设计步骤,重点讨论了数据仓库多维数据结构的设计。