Optimal production and maintenance policy for imperfect production systems

A joint optimization of the production run length and preventive maintenance (PM) policy is studied for a deteriorating production system where the in‐control period follows a general probability distribution with non‐decreasing failure rate. In the literature, the sufficient conditions for the optimality of the equal‐interval PM schedule is explored to derive an optimal production run length and an optimal number of PM actions. Nevertheless, an exhaustive search may arise. In this study, based on the assumption that the conditions for the optimality of the equal‐interval PM schedule hold, we derive some structural properties for the optimal production/PM policy, which increases the efficiency of the solution procedure. These analyses have implications for the practical application of the production/PM model to be more available in practice. A numerical example of gamma shift distribution with non‐decreasing failure rates is used to illustrate the solution procedure, leading to some insight into the management process. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

一种增强嵌入式系统安全性的安全防护技术*

由于嵌入式应用环境的多样性,单纯软件或硬件安全技术或者安全产品的功能和性能都有其局限性,只能满足某类系统的特定安全需求。因此,如何有效利用软硬件技术特点,通过协同防护来保障系统的安全已成为当前信息安全领域的研究热点。通过对嵌入式系统安全威胁和隐患的分析,在此基础上提出一种可以提高嵌入式系统安全性的软硬协同安全防护技术。该技术通过硬件检测、软件处理、综合治理的方法,可以有效地增强嵌入式系统抗击本身缺陷和恶意攻击的能力。     

The impact of manufacturer rebates on supply chain profits

Manufacturer rebates are commonly used as price discount tools for attracting end customers. In this study, we consider a two‐stage supply chain with a manufacturer and a retailer, where a single seasonal product faces uncertain and price‐sensitive demand. We characterize the impact of a manufacturer rebate on the expected profits of both the manufacturer and the retailer. We show that unless all of the customers claim the rebate, the rebate always benefits the manufacturer. Our results thus imply that “mail‐in rebates,” where some customers end up not claiming the rebate, particularly when the size of the rebate is relatively small, always benefit the manufacturer. On the other hand, an “instant rebate,” such as the one offered in the automotive industry where every customer redeems the rebate on the spot when he/she purchases a car, does not necessarily benefit the manufacturer. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Integrated capacity,demand, and production planning with subcontracting and overtime options

Models for integrated production and demand planning decisions can serve to improve a producer's ability to effectively match demand requirements with production capabilities. In contexts with price‐sensitive demands, economies of scale in production, and multiple capacity options, such integrated planning problems can quickly become complex. To address these complexities, this paper provides profit‐maximizing production planning models for determining optimal demand and internal production capacity levels under price‐sensitive deterministic demands, with subcontracting and overtime options. The models determine a producer's optimal price, production, inventory, subcontracting, overtime, and internal capacity levels, while accounting for production economies of scale and capacity costs through concave cost functions. We use polyhedral properties and dynamic programming techniques to provide polynomial‐time solution approaches for obtaining an optimal solution for this class of problems when the internal capacity level is time‐invariant. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

The strategic effects of a merger upon supplier interactions

We consider how a merger between two naturally differentiated dealers affects their interactions with a common supplier and identify conditions under which the merger can increase or decrease the combined net worth of the two firms. Among other things, we find that the attractiveness of merging depends upon the extent to which end demand can be stimulated by either an upstream supplier or the dealers. Specifically, the greater the supplier's ability to invest in stimulating end demand, the more likely it is that the naturally differentiated firms will be better off operating independently than merging. On the other hand, if the greatest opportunities for stimulating demand are through the service that is provided by the dealers, then merging their operations will be more attractive. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

噪声目标转向机动自动检测

根据观测器--目标保持匀速直线运动时目标方位随时间线性变化的一种可量测函数,研究了一种检测目标转向机动的新方法.由于该方法将目标方位随时间变化的非线性关系转换到另一空间的线性关系,这使得检测更加有效、直观,并且能够克服直接采用方位序列检测目标转向机动在特殊情况下失效的限制.最后计算机仿真计算及实测数据验证结果表明,该方法能快速、准确地检测目标的转向机动.     

消防执法引入零容忍政策探析

为了更好地打击消防违法、整治火灾隐患、维护公共安全,探索在消防执法中引入零容忍政策。介绍了零容忍政策的由来及理论依据,分析了消防执法引入零容忍政策的必要性,探讨了实施零容忍打击消防违法、消除火灾隐患的具体意见。     

1．06μm连续激光辐照GaAs探测器的理论研究

建立了高斯型连续激光辐照GaAs探测器物理模型,近似解析计算了圆柱形GaAs靶板的三维温度场.数值分析了激光辐照时GaAs探测器的信号异常及熔融损伤的情况,并计算了相应的损伤阈值.理论计算与实验结论能够精确的一致,理论模型为评论同类激光效应以及激光对抗的激光加固提供了参考.     

基于LabVIEW的变速箱状态检测系统

采用门限关联度理论进行变速箱状态检测,并构建了以虚拟仪器为核心的变速箱状态采集系统,建立了表征变速箱状态的特征参量和正常故障判定准则,采用LabVIEW开发了检测与故障判定软件系统。     

基于策略的网络管理系统的实现

结合网络管理的发展情况,对基于策略的网络管理技术当前所处的地位和发挥的作用进行了探讨。并论述了一种基于策略的网络管理系统的具体实现,其中重点阐述了策略的表现形式和策略管理中基线的分析技术。