Generalizing the survival signature to unrepairable homogeneous multi‐state systems

The notion of signature has been widely applied for the reliability evaluation of technical systems that consist of binary components. Multi‐state system modeling is also widely used for representing real life engineering systems whose components can have different performance levels. In this article, the concept of survival signature is generalized to a certain class of unrepairable homogeneous multi‐state systems with multi‐state components. With such a generalization, a representation for the survival function of the time spent by a system in a specific state or above is obtained. The findings of the article are illustrated for multi‐state consecutive‐k‐out‐of‐n system which perform its task at three different performance levels. The generalization of the concept of survival signature to a multi‐state system with multiple types of components is also presented. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 593–599, 2017     

通用装备机械液压系统综合检测试验平台的设计与研制

针对目前通用装备保障建设过程中存在的保障设备通用性差、综合功能弱、机动性能差及信息化程度低等问题,提出了"划类分组、综合集成、一体通用"的设计思想,研制了可完成军械、装甲、工程、防化、车辆、陆军船艇等装备机械液压系统技术状况检测与评估、故障诊断、部(元)件修后试验与质量评估、信息管理等功能的综合机动平台。重点阐述了平台各系统的设计思想、硬件组成及软件框架。实际应用表明,该平台具有"广谱"、"广域"和"全时"的能力,其推广使用将为通用装备保障由"基于型号"向"基于能力"的建设转型提供成功示范。     

Lipschitz非线性系统状态观测器设计新方法

针对Lipschitz非线性系统状态观测器,提出了一种以极小化条件数为目标准则的新的设计方法。运用梯度下降法和Slyvester方程,计算极小化条件数,优化增益矩阵和最大允许Lipschitz常数,完成观测器设计。通过同其它文献的算例比较,结果发现按文中方法设计的观测器具有迭代次数少、优化结果好的特点。     

预警探测体系作战效能评估框架

首先阐述了预警探测体系及其效能评估的概念,根据预警探测体系及其作战任务的特点,建立了效能评价指标体系,并给出了部分效能指标的评估计算模型,最后提出了预警探测体系作战效能评估的框架和一般过程.     

含内聚空洞固体发动机药柱的寿命预估

为了对含内聚空洞固体导弹发动机的贮存寿命进行预估,采用加速老化试验,得到该推进剂最大延伸率随贮存时间的变化规律;应用三维粘弹性有限元分析方法,对含内聚空洞的发动机贮存一定时间后直接点火发射过程进行数值仿真,从中获得发动机药柱在点火增压和轴向过载联合作用下的最大Von Mises应变.将不同贮存期药柱的最大Von Mises应变值与推进剂的最大延伸率进行对比,利用结构完整性评估准则,给出了某发动机药柱不同贮存期间内聚空洞大小的允许值.该方法可为含内聚空洞固体发动机的判废提供定量参考.     

一种面向分布式寄存器文件的VLIW调度新策略

新一代面向密集计算的高性能处理器普遍采用分布式寄存器文件来支撑ALU阵列,并通过VLIW开发指令级并行.面向分布式寄存器文件的编译成为新兴的研究热点,在斯坦福大学的kernelC编译器ISCD中最早提出了面向分布式寄存器的VLIW调度问题,在该领域处于领先水平,但是没有解决重负载下的分布式寄存器分配问题,使应用编程受到极大限制.在其基础上提出了一种新的VLIW调度策略,实验结果表明能够很好地解决重负载下的分布式寄存器分配问题.     

Optimal capacity in a coordinated supply chain

We consider a supply chain in which a retailer faces a stochastic demand, incurs backorder and inventory holding costs and uses a periodic review system to place orders from a manufacturer. The manufacturer must fill the entire order. The manufacturer incurs costs of overtime and undertime if the order deviates from the planned production capacity. We determine the optimal capacity for the manufacturer in case there is no coordination with the retailer as well as in case there is full coordination with the retailer. When there is no coordination the optimal capacity for the manufacturer is found by solving a newsvendor problem. When there is coordination, we present a dynamic programming formulation and establish that the optimal ordering policy for the retailer is characterized by two parameters. The optimal coordinated capacity for the manufacturer can then be obtained by solving a nonlinear programming problem. We present an efficient exact algorithm and a heuristic algorithm for computing the manufacturer's capacity. We discuss the impact of coordination on the supply chain cost as well as on the manufacturer's capacity. We also identify the situations in which coordination is most beneficial. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

Factors that affect the optimal amount of central control in complex systems

Whereas much of the previous research in complex systems has focused on emergent properties resulting from self‐organization of the individual agents that make up the system, this article studies one vital role of central organization. In particular, four factors are conjectured to be key in determining the optimal amount of central control. To validate this hypothesis, these factors are represented as controllable parameters in a mathematical model. For different combinations of parameter values, the optimal amount of central control is found, either analytically or by computer simulation. The model is shown to provide results that match well with the level of control found across a broad spectrum of specific complex systems. This model also provides general guidelines as to how combinations of these factors affect the desirable level of control and specific guidelines for selecting and evaluating leaders. These results indicate that all of these factors, though not exhaustive, should be considered carefully when attempting to determine the amount of control that is best for a system. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

技术保障信息化分布式数据库系统研究

针对我军装甲装备技术保障信息化建设的特点和要求,应用分布式数据库理论,提出了建立装甲装备技术保障分布式数据库系统的方法,阐述了实现该系统的设计要求和关键技术。     

一种新型的P2P Tracker实现方法

流媒体数据已经在互联网流量中占据极高的比例,P2P是目前支撑互联网流媒体数据分发的重要手段。本文提出一种新型的P2P Tracker实现方法——eTracker。该方法通过网络边缘的eTracker分布实现peer列表的保存,不但消除传统集中式Tracker的性能瓶颈,而且通过eTracker对本地peer的识别,优化了P2P系统的peer选择。