Optimal stopping in software testing

In this paper we address the problem of how to decide when to terminate the testing/modification process and to release the software during the development phase. We present a Bayesian decision theoretic approach by formulating the optimal release problem as a sequential decision problem. By using a non‐Gaussian Kalman filter type model, proposed by Chen and Singpurwalla (1994), to track software reliability, we are able to obtain tractable expressions for inference and determine a one‐stage look ahead stopping rule under reasonable conditions and a class of loss functions. © 2002 Wiley Periodicals, Inc. Naval Research Logistics, 2003     

基于Petri网的某引信安全系统软件安全性分析

介绍了软件安全性和基于Petri网软件安全性分析技术。结合某导弹安全系统的实例,在系统Petri网模型的基础上运用逆向可达图回溯法及关键状态法对系统及其软件的设计进行了安全性分析,还考虑了系统运行时的动态时效对安全性的影响及相应的恢复措施。总结了基于Petri网的系统软件安全性分析的特点。     

考虑资源约束的复杂维修任务时间预计模型

在分析装备维修过程时间影响因素的基础上,研究了维修过程时间模型的建模要素关系。采用Petri网技术建立了反映子任务基本关系、资源约束和调度策略的典型维修过程模型,并对典型子任务执行过程进行了细化建模,研究了模型冲突和资源调度策略。针对典型实例进行了维修时间预计和资源利用率分析。     

基于Petri网的指挥流程建模与优化

鉴于Petri网在企业业务流程优化与重组方面的成功运用,遂将Petri网原理应用于作战指挥流程的建模与优化,以期获得最优作战指挥流程.文中首先阐述Petri网基本原理,然后介绍指挥流程建模的Petri网模型,最后给出指挥流程优化的原则及基本模型,并利用Petri网对指挥流程进行建模和优化,结果表明Petri网理论能够明显优化作战指挥流程.提高作战指挥效率.     

防空组网雷达“四抗”能力综合评估

为正确评估防空组网雷达"四抗"能力,结合雷达组网的因素分析,建立了组网雷达系统层次结构模型,并利用层次分析法确定了各因素的权重,用最优指标法得出指标层的得分值,提出了组网雷达"四抗"综合能力量化评估方法.其评估结果在一定程度上为组网雷达性能优化提供了决策依据.     

随机动态规划的混合算法研究

针对随机条件下动态规划模型的主要特点,运用智能算法混合编程理论,设计了一种探索多阶段决策问题的智能混合算法.该算法首先将问题转化成一族同类型的一步决策子问题,然后利用随机模拟和遗传算法,依据训练样本形成的训练神经元网络,在单步决策中寻求最优策略和最优目标值,逐个求解,再据初始状态逆序求出最优策略序列和最优目标值.仿真结果表明,该算法具有一定的通用性,初始设计点可以随机产生,其计算精度不因函数的非线性强弱而受影响,对目标和约束的限制较少,可应用于多种形式的随机多阶段决策优化问题,较好地满足了随机动态规划模型求解和优化的要求.     

To wait or not to wait: Optimal ordering under lead time uncertainty and forecast updating

There has been a dramatic increase over the past decade in the number of firms that source finished product from overseas. Although this has reduced procurement costs, it has increased supply risk; procurement lead times are longer and are often unreliable. In deciding when and how much to order, firms must consider the lead time risk and the demand risk, i.e., the accuracy of their demand forecast. To improve the accuracy of its demand forecast, a firm may update its forecast as the selling season approaches. In this article we consider both forecast updating and lead time uncertainty. We characterize the firm's optimal procurement policy, and we prove that, with multiplicative forecast revisions, the firm's optimal procurement time is independent of the demand forecast evolution but that the optimal procurement quantity is not. This leads to a number of important managerial insights into the firm's planning process. We show that the firm becomes less sensitive to lead time variability as the forecast updating process becomes more efficient. Interestingly, a forecast‐updating firm might procure earlier than a firm with no forecast updating. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009     

What you should know about approximate dynamic programming

Approximate dynamic programming (ADP) is a broad umbrella for a modeling and algorithmic strategy for solving problems that are sometimes large and complex, and are usually (but not always) stochastic. It is most often presented as a method for overcoming the classic curse of dimensionality that is well‐known to plague the use of Bellman's equation. For many problems, there are actually up to three curses of dimensionality. But the richer message of approximate dynamic programming is learning what to learn, and how to learn it, to make better decisions over time. This article provides a brief review of approximate dynamic programming, without intending to be a complete tutorial. Instead, our goal is to provide a broader perspective of ADP and how it should be approached from the perspective of different problem classes. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

C~4ISR系统任务实时性的评价方法

提出一种定量评价C4ISR(Command Control Communication Computer Intelligence Surveillance and Reconnaissance)系统任务实时性方法--时序着色模糊时间Petri网(TCFTPN)方法.用时序逻辑公式来限制着色Petri网的变迁引发行为,用模糊时间来表示各工作过程的时延特性和降级工作问题.通过估计在规定的时间内标识从任务开始状态到达任务完成状态的概率来确定C4ISR系统的任务实时性.     

战术数据链网络设计优化方法

网络设计优化问题直接关系到战术数据链系统效能的发挥。在分析数据链系统中不同消息类别有不同系统响应时间要求的基础上,提出了一种新的网络设计优化方法。通过建立模型讨论了单个数据链轮询网络的轮询周期、网络成员容量、每个轮询周期内各成员的点名次数等因素间的数学关系。并以Link-11为例进行分析计算。结果表明,该分析方法有效可行,为解决战术数据链网络设计及优化问题提供了一种思路。