Minimizing the false alarm rate in systems with transient abnormality

We consider a stochastic partially observable system that can switch between a normal state and a transient abnormal state before entering a persistent abnormal state. Only the persistent abnormal state requires alarms. The transient and persistent abnormal states may be similar in appearance, which can result in excess false alarms. We propose a partially observable Markov decision process model to minimize the false alarm rate, subject to a given upper bound on the expected alarm delay time. The cost parameter is treated as the Lagrange multiplier, which can be estimated from the bound of the alarm delay. We show that the optimal policy has a control‐limit structure on the probability of persistent abnormality, and derive closed‐form bounds for the control limit and present an algorithm to specify the Lagrange multiplier. We also study a specialized model where the transient and persistent abnormal states have the same observation distribution, in which case an intuitive “watchful‐waiting” policy is optimal. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 320–334, 2016     

Bayesian enhanced decision making for deteriorating repairable systems with preventive maintenance

Since a system and its components usually deteriorate with age, preventive maintenance (PM) is often performed to restore or keep the function of a system in a good state. Furthermore, PM is capable of improving the health condition of the system and thus prolongs its effective age. There has been a vast amount of research to find optimal PM policies for deteriorating repairable systems. However, such decisions involve numerous uncertainties and the analyses are typically difficult to perform because of the scarcity of data. It is therefore important to make use of all information in an efficient way. In this article, a Bayesian decision model is developed to determine the optimal number of PM actions for systems which are maintained according to a periodic PM policy. A non‐homogeneous Poisson process with a power law failure intensity is used to describe the deteriorating behavior of the repairable system. It is assumed that the status of the system after a PM is somewhere between as good as new for a perfect repair and as good as old for a minimal repair, and for failures between two preventive maintenances, the system undergoes minimal repairs. Finally, a numerical example is given and the results of the proposed approach are discussed after performing sensitivity analysis. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

基于ARIS的战时修理业务流程仿真研究

利用ARIS建模方法与工具，对战时装备修理业务流程进行了仿真研究。以陆军某机步师某型装备为例，给出了战时修理业务的主流程模型以及各分支模型，通过仿真运行及结果分析，得出了制约该流程的瓶颈和需要进一步优化的对象，为装备维修保障过程仿真提供了一个很好的思路和方法。该方法对于开发战时维修保障效能仿真评估系统，实现维修保障系统的动态仿真和全要素评估具有重要的支撑作用。     

基于资源平衡的分布式星群网络连接接入策略

针对现有卫星网络接入策略未能充分考虑卫星资源以及合理确定卫星资源权重问题,提出了一种基于资源平衡的星群网络连接接入策略。该策略充分考虑卫星的多种资源建立卫星资源评价模型,利用移动代理技术,采用层次分析法和熵值法计算各卫星资源的主观和客观权重,并通过Kullback散度权重优化方法对主客观权重进行平衡处理,判决过程兼顾了卫星的综合性能水平和用户偏好,提高了接入的准确性和合理性。仿真结果表明,采用该接入策略,有效改善了新呼叫阻塞率和强制中断率。     

AHP及其在潜艇作战指挥上的应用

层次分析法(AHP)是一种简便的、实用的多准则决策分析方法.在对传统的AHP进行概述的基础上,针对其在实际应用中存在的问题,介绍了国内外几种经典的综合及改进的层次分析法,并建立了较为完备的潜艇作战指挥效能的评价体系和模糊综合评价模型,对潜艇的作战指挥效能进行了综合的定量分析和计算.最后展望了AHP在潜艇作战指挥上的应用前景,并对各种AHP进行了比较.     

信息网络作战技术

信息战是现代战争中重要作战样式,网络战是信息战的重要组成部分,分布式、网络化的计算机系统是信息作战中实施攻击与防护首要作战目标。根据网络作战的需求,从技术角度出发,首先对网络战的要素组成进行了分析,在此基础上将网络战划分为两个阶段,并对此进行了深入研究,最后提出了实施网络战的方法与步骤。     

使用图像优化方法估计水体调制传递函数

针对水体属性的变化使图像复原困难的问题,提出了一种从退化的水下图像中估计自然水体调制传递函数的方法。该方法首先建立了自然水体的调制传递函数与其固有光学特性参数之间的关系,然后采用图像复原技术对图像进行复原,最后使用粒子群优化算法来优化调制传递函数的相关参数。仿真实验表明:该方法能有效对水下图像进行复原,且不需测量水体的光学参数就能估计出自然水体的调制传递函数。该方法用于水下激光成像系统的图像复原可取得明显效果。     

基于模糊物元分析法的坦克作战效能评估

鉴于坦克作战效能评估中客观存在的不确定性和模糊性,提出了基于改进模糊物元分析方法的坦克作战效能评估模型。该模型在构建坦克作战效能评估指标体系基础上,将层次分析法和熵权法计算出的权重有机组合实现综合赋权,并据此建立坦克作战效能的模糊物元分析评估模型。实例分析表明,所提出的模型便于理解,易于实现,兼顾了主客观因素的影响,评估结果总体反映了坦克作战效能的真实水平,也为其他装甲武器作战效能的科学评估提供新思路。     

箔条云干扰下的单目标恒虚警率检测研究

箔条云在扩散过程中随着时间变化会稀释和扩大,其回波特性会发生改变,被检测目标与箔条的相互位置关系也会影响雷达恒虚警检测。针对作战对抗过程中箔条干扰易造成雷达接收机阻塞干扰目标检测,检测概率迅速降低且易丢失目标贻误战机,通过详细分析箔条的扩散过程及信号频谱特性及其箔条云和目标的两种位置关系,利用恒虚警处理算法在噪声基底为10 dB和20 dB情况下对目标进行恒定虚警率检测研究。研究结果对改善飞机检测性能和抗虚警能力以及提高战场生存率具有积极作用。     

基于“综合赋权”模糊物元模型的机场运行安全评价

为了保证机场运行安全,防止事故的发生,依据模糊物元分析理论,结合机场运行安全评价指标体系,构建了基于综合赋权的机场系统模糊物元安全评价模型。在该模型中,通过层次分析法和熵值法主客观综合所确定的权重,为指标体系进行线性加权,实现综合赋权,从而将计算得到的综合权重用于模糊物元建模与评价。实例分析结果表明,该模型步骤简单,过程科学合理,并兼顾了主客观因素的影响,评价结果总体反映了机场的真实安全水平,也为机场安全的科学评价提供了新思路。