一种基于任务-系统结构的软件可靠性建模方法

针对军用软件特点,提出并定义一种基于任务剖面的软件系统结构准则;基于该准则,给出一种从功能可靠性、事件可靠性到任务可靠性的分层可靠性预计方法。与侧重于数学建模的相关工作不同,该方法更注重在建模中融合软件可靠性设计、测试和管理,成为可靠性保证的一种途径。     

Integrated production scheduling and preventive maintenance planning for a single machine under a cumulative damage failure process

This paper finds the optimal integrated production schedule and preventive maintenance plan for a single machine exposed under a cumulative damage process, and investigates how the optimal preventive maintenance plan interacts with the optimal production schedule. The goal is to minimize the total tardiness. The optimal policy possesses the following properties: Under arbitrary maintenance plan when jobs have common processing time, and different due dates, the optimal production schedule is to order the jobs by earliest due date first rule; and when jobs have common due date and different processing times, the optimal production schedule is shortest processing time first. The optimal maintenance plan is of control limit type under any arbitrary production schedule when machine is exposed under a cumulative damage failure process. Numerical studies on the optimal maintenance control limit of the maintenance plan indicate that as the number of jobs to be scheduled increases, the effect of jobs due dates on the optimal maintenance control limit diminishes. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Machine maintenance with workload considerations

Machine maintenance is modeled in the setting of a single‐server queue. Machine deterioration corresponds to slower service rates and failure. This leads to higher congestion and an increase in customer holding costs. The decision‐maker decides when to perform maintenance, which may be done pre‐emptively; before catastrophic failures. Similar to classic maintenance control models, the information available to the decision‐maker includes the state of the server. Unlike classic models, the information also includes the number of customers in queue. Considered are both a repair model and a replacement model. In the repair model, with random replacement times, fixed costs are assumed to be constant in the server state. In the replacement model, both constant and variable fixed costs are considered. It is shown in general that the optimal maintenance policies have switching curve structure that is monotone in the server state. However, the switching curve policies for the repair model are not always monotone in the number of customers in the queue. Numerical examples and two heuristics are also presented. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

基于卫星数据链路的飞机主动维修保障系统

基于北斗卫星数据链路,采用了"空-地"两级数据处理方式进行飞行参数在线判读、主动维修保障及安全监控系统的实时处理。分析了主动维修保障及飞机实时状态监控、北斗短报文系统的基本情况,并着重介绍了系统的总体结构和优势,以及包括机载部分、地面处理系统和北斗卫星数传装置三部分的工作原理和设备构成。     

地下工程火灾环境对无线信号传输的影响

通过全尺寸实火试验和计算机模拟,分析和研究了地下工程火灾环境对无线信号传输效果的影响,并基于无线信号传输常规模型,假设地下工程火灾条件下的无线信号传输的数学模型,得出接受信号强度RSSI值的衰减与温度变化、烟气浓度变化的关系,通过分析数据之间的关系,得出地下工程中火灾环境下的无线信号传输损耗指数的值,最终建立起地下工程火灾环境下的无线信号传输模型.为复杂环境消防通信问题的研究奠定基础.     

基于遗传算法的装备维修方案多目标优化

针对装备维修方案规划的特点,构建了以维修费用最低和作战能力最大的多目标装备维修方案优化模型,并提出针对该模型求解的改进多目标遗传优化算法。在遗传算法设计中,为保证解集的均匀性和多样性,避免过早收敛,建立了随机权重适应度函数,引入精英保留机制和小生境技术,通过实例对该模型的求解进行了验证。仿真结果表明,所构建的模型合理可行,算法运行高效,为部队装备维修方案的制定提供了一定的借鉴。     

增强现实诱导维修在外军的发展现状和趋势

随着战场环境逐步复杂化和武器装备日益信息化,军用装备维修难度不断增加。针对这一难题,介绍了以增强现实为基础发展起来的增强现实诱导维修技术。分析增强现实诱导维修的基本概念及系统基本构成的同时得出其在未来军事活动中的优势所在。通过介绍国外增强现实诱导维修的发展历程和在军事领域的应用,进一步展望了其在军事领域的发展趋势,对装备维修具有一定的指导意义。     

定期维护与事后修理组合的维修策略

为了客观合理地制定产品的定期维护与事后修理组合的维修策略,分析了该组合策略下产品的性能变化特点,并从失效机理出发,利用复合Poisson过程描述了产品性能退化规律,建立了以产品长期运行下费用率最低为目标的优化模型,并通过求解得到了最优的维护周期.最后,实例分析表明:该方法能够较好地描述产品的性能退化规律;同时,优化得到的维修策略值可以有效地降低维修费用,并延长产品使用寿命.     

装备分布式虚拟维修训练仿真负载平衡研究

基于HLA的装备分布式虚拟维修训练过程极易产生仿真节点负载失衡,以往的负载平衡研究多关注资源利用率,仿真运行过程中可能会因节点负载的不均衡进行频繁的负载调度,影响仿真运行效率.针对此问题,以保证仿真节点的高效运行为首要目的,将负载平衡定义为不存在超载节点即为平衡,提出了一种动静结合的复合式负载平衡调度方法.研究了复合式负载平衡系统的体系结构,采用最小连接调度法实现了节点静态负载的粗粒度平衡,引入仿真运行比率分量参数表征负载量值,进而设计了动态负载平衡算法对仿真运行过程进行实时监控和调度.实验结果表明,改进后仿真平衡调度频率明显下降,实现了资源利用率和仿真效率的平衡兼顾,取得了良好的效果.     

美军现役装备改造后维修保障的做法和启示

现役装备改造是我军装备发展的重要途径.加强对现役装备改造后的维修保障问题研究,是解决目前我军装备改造后战斗力生成的迫切需要.通过深入研究了美军装备改造后维修保障基本做法,对我军当前存在的主要问题进行了探讨,并从中得出对我军加强装备改造后维修保障建设与发展的启示,为提高我军装备维修保障能力做了有益的探索.