Optimal burn‐in procedure for periodically inspected systems

Burn‐in is a widely used method to improve the quality of products or systems after they have been produced. In this paper, we study burn‐in procedure for a system that is maintained under periodic inspection and perfect repair policy. Assuming that the underlying lifetime distribution of a system has an initially decreasing and/or eventually increasing failure rate function, we derive upper and lower bounds for the optimal burn‐in time, which maximizes the system availability. Furthermore, adopting an age replacement policy, we derive upper and lower bounds for the optimal age parameter of the replacement policy for each fixed burn‐in time and a uniform upper bound for the optimal burn‐in time given the age replacement policy. These results can be used to reduce the numerical work for determining both optimal burn‐in time and optimal replacement policy. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Modeling and analysis of a mixed‐model assembly line with stochastic operation times

We consider a mixed‐model assembly line (MMAL) comprised a set of workstations and a conveyor. The workstations are arranged in a serial configuration. The conveyor moves at a constant speed along the workstations. Initial units belonging to different models are successively fed onto the conveyor, and they are moved by the conveyor to pass through the workstations to gradually generate final products. All assembling tasks are manually performed with operation times to be stochastic. An important performance measure of MMALs is overload times that refer to uncompleted operations for operators within their work zones. This paper establishes a method to analyze the expected overload times for MMALs with stochastic operation times. The operation processes of operators form discrete time nonhomogeneous Markov processes with continuous state spaces. For a given daily production schedule, the expected overload times involve in analyzing the Markov processes for finite horizon. Based on some important properties of the performance measure, we propose an efficient approach for calculating the expected overload times. Numerical computations show that the results are very satisfactory. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Technical note: Worst‐case performance of power‐of‐two policies for serial inventory systems with incremental quantity discounts

This study presents power‐of‐two policies for a serial inventory system with constant demand rate and incremental quantity discounts at the most upstream stage. It is shown that an optimal solution is nested and follows a zero‐inventory ordering policy. To prove the effectiveness of power‐of‐two policies, a lower bound on the optimal cost is obtained. A policy that has a cost within 6% of the lower bound is developed for a fixed base planning period. For a variable base planning period, a 98% effective policy is provided. An extension is included for a system with price dependent holding costs. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

舰载导弹垂直发射系统的综合测控系统

通过对舰载导弹垂直发射系统中贮运发射箱内环境监控、导弹综合测试、发射过程控制、射击参数装定以及应急状态自动处理等需求分析,提出建立综合测控系统方案,并探讨了以LONworks总线为核心的综合测控系统基本结构、组成和功用.     

地(舰)空导弹测试系统的设计方法探讨

导弹测试系统是进行导弹综合测试的专用地面设备系统。导弹测试系统的特点是多方面的, 包括： 测试功能全面、综合; 系统组成设备类型较多;测试安全性要求突出。如何进行导弹测试系统的优化设计, 是文章阐述内容的主题     

数字式稳态频率特性测试仪设计

通用频率特性测试仪在使用中存在两个问题：一是与计算机接口困难,二是稳态测试和暂态测试相互影响导致测试结果不准确。在微处理器控制下,数字分频器和锁相环提供精确的点频激励源,程控数据采集电路处理响应信号。根据这一原理构成的数字式稳态频率特性测试仪较好地解决了上述问题。     

采用神经网络技术降低机电设备BIT虚警

机电设备 Ｂ Ｉ Ｔ 的突出问题是虚警率高，重要原因之一是 Ｂ Ｉ Ｔ 系统传感器通路故障。本文选取神经网络技术进行传感器通路故障诊断，剖析某大型船舶动力装置机电设备 Ｂ Ｉ Ｔ 系统中传感器通路的故障机理和类型，得到其故障样本数据，经过神经网络学习训练后对实际系统进行故障诊断和识别，实验结果表明该方法简洁、有效，能够有效地诊断故障并识别出故障类型，具有实用价值。     

特大规模组合电路高速测试生成系统ATGTA-1

针对特大规模组合电路和全扫描设计电路提出了一种高速测试生成方法，并建成了相应的测试生成系统ＡＴＧＴＡ－１。该系统采用有限回溯测试模式产生方法生成测试码，采用ｎ（机器字长）个测试码并行的单故障传播方法模拟验证测试覆盖。测试生成与故障模拟为ｎ对１紧耦合集成方式。该系统运行１０个Ｂｅｎｃｈｍａｒｋ电路，取得了低测试长度、高故障覆盖、高效率的良好效果。     

VXI Plug & Play : 一种组建测试系统的理想规范

介绍了对推动ＶＸＩ技术发展具有重要意义的ＶＸＩＰｌｕｇ＆Ｐｌａｙ系统联盟成立的背景以及ＶＸＩＰｌｕｇ＆Ｐｌａｙ规范的主要内容,制定规范所遵循的原则和要求,对ＶＸＩＰｌｕｇ＆Ｐｌａｙ发展前景做了展望,说明了虚拟仪器软件结构的框架,并初步探讨了组建一个自动测试系统的方法和步骤以及如何利用ＶＸＩＰｌｕｇ＆Ｐｌａｙ设计仪器驱动程序。     

Weibull 分布场合下恒定应力加速寿命试验的保序估计

讨论了Ｗｅｉｂｕｌ场合下恒定应力加速寿命试验的最优线性无偏估计及保序估计,获得了保序估计的表示式,并给出了一个模拟例子．