Monitoring censored lifetime data with a weighted‐likelihood scheme

Lifetime experiments are common in many research areas and industrial applications. Recently, process monitoring for lifetime observations has received increasing attention. However, some existing methods are inadequate as neither their in control (IC) nor out of control (OC) performance is satisfactory. In addition, the challenges associated with designing robust and flexible control schemes have yet to be fully addressed. To overcome these limitations, this article utilizes a newly developed weighted likelihood ratio test, and proposes a novel monitoring strategy that automatically combines the likelihood of past samples with the exponential weighted sum average scheme. The proposed Censored Observation‐based Weighted‐Likelihood (COWL) control chart gives desirable IC and OC performances and is robust under various scenarios. In addition, a self‐starting control chart is introduced to cope with the problem of insufficient reference samples. Our simulation shows a stronger power in detecting changes in the censored lifetime data using our scheme than using other alternatives. A real industrial example based on the breaking strength of carbon fiber also demonstrates the effectiveness of the proposed method. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 631–646, 2017     

A stochastic assignment problem

There are n boxes with box i having a quota value Balls arrive sequentially, with each ball having a binary vector attached to it, with the interpretation being that if X_i = 1 then that ball is eligible to be put in box i. A ball's vector is revealed when it arrives and the ball can be put in any alive box for which it is eligible, where a box is said to be alive if it has not yet met its quota. Assuming that the components of a vector are independent, we are interested in the policy that minimizes, either stochastically or in expectation, the number of balls that need arrive until all boxes have met their quotas. © 2014 Wiley Periodicals, Inc. 62:23–31, 2015     

激光测距系统控制策略研究的一种新方法

首先运用更新理论研究了激光测距系统漏测点的分布规律,在该系统跟踪目标的角误差为平稳高斯过程的前提下,给出了易于计算的漏测点分布律的显式表示,为求取使不可补漏测点出现概率最小的控制策略提供了一条行之有效的新途径。     

Testing or fault-finding for reliability growth: A missile destructive-test example

A new piece of equipment has been purchased in a lot of size m. Some of the items can be used in destructive testing before the item is put into use. Testing uncovers faults which can be removed from the remaining pieces of equipment in the lot. If t < m pieces of equipment are tested, then those that remain, m₁ = m − t, have reduced fault incidence and are more reliable than initially, but m₁ may be too small to be useful, or than is desirable. In this paper models are studied to address this question: given the lot size m, how to optimize by choice of t the effectiveness of the pieces of equipment remaining after the test. The models used are simplistic and illustrative; they can be straightforwardly improved. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 623–637, 1997     

给定人员情况下最小化开发时间和成本的软件项目调度

给出了一种软件项目的随机调度模型.它明确地把调度策略作为输入,一旦调度策略确定,模型就可以输出关于项目的完成时间或成本的一个概率分布.利用随机最优化技术,能够计算出软件项目的一个调度策略,它使得项目在人员给定的情况下开发时间和成本最小.     

产品网络化协同开发系统信息处理模型研究

产品网络协同开发系统信息处理模型是现代制造企业从事产品开发、提高企业核心竞争力的关键。在分析产品网络化协同开发系统现状的基础上,阐明了产品网络化协同开发系统的基本内涵及实现方法。提出了基于输入、输出、知识、关系、方法和时间约束六个方面组成的产品网络化协同开发系统的信息处理统一模型;建立了一个面向产品开发全过程协同的信息流模型,构建了产品网络化协同开发平台信息流模型的软件结构,为制造企业建立产品网络协同开发平台,实现产品开发过程的信息化、科学化和规范化进行了有益的工作。     

层次分析法中一致性检验的一种调整方法

针对层次分析法中一致性检验难以通过的问题,提出了一种优化调整方法,并分析了该方法的基本思路及可行性。为方便上机编程,还给出了该方法的具体实现步骤。     

软件可靠性的过程仿真技术

以软件研制的生命周期为背景,探讨利用仿真模型对软件可靠性进行研究的方法．文章阐述了仿真模型分析方法与传统的模型分析方法的不同之处,通过对软件可靠性过程的分析,设计了一个基本的仿真器结构,由此考察引发失效行为的各种故障因素及其对软件可靠性的影响．     

新型船用气体稳压器启动充气过程的建模及仿真研究

基于船用核动力一体化反应堆结构的需要,建立了新型船用气体稳压器启动充气过程的数学模型,并进行了仿真计算.计算结果表明,该模型能正确地描述该型稳压器实际的启动充气过程,满足工程设计及系统研究的需要.     

卫星军事应用系统作战效能评估的网络层次分析法研究

根据卫星军事应用系统的特点研究了基于网络层次分析法的效能评估方法.确立了效能评价的准则,给出了影响其作战效能的指标集,建立了网络层次分析法控制层和网络层模型,并且利用计算极限超矩阵的方法对单个准则下各方案的作战效能进行排序.最后,通过对单个准则下的排序向量进行加权求和获得卫星军事应用系统作战效能的排序向量.