基于单一聚类方法的航空器相撞HFACS诱发模式分析

为了有效防控航空器相撞事故的发生,保证航空系统安全、有序和高效运行,提出一种基于单一聚类过程的人为因素分析分类系统(HFACS)诱发模式分析方法。在该方法中,首先,根据航空器相撞的具体特点建立了HFACS。然后,利用HFACS对发生的航空器相撞事故/事故征候进行量化,构建历史信息的数据表。最后,采用单一聚类方法对得到的数据表进行诱发模式分析,识别出重要的诱发模式及模式中包含的重要影响因素,并据此提出防相撞的管控措施。实例分析表明,所提出方法的实现过程简便,定性定量结合,形式易于理解,分析结果也更加贴近实际,对于提升防相撞的管理和决策水平,防范航空器相撞及减少造成的损失具有重要的实用价值。     

多击痕轮廓最小外接圆法测量击针偏心度

针对两个以上的击痕会有重叠不利于单个击痕轮廓圆拟合的问题,提出了一种通过测量多个击痕整体轮廓的最小外接圆来实现火炮击针偏心度检测的方法。首先,对药筒进行单次击发,获得底火上单个击痕的图像,并拟合出单个击痕的圆半径;然后,再对药筒进行不少于3次的击发,任意两次击发之间药筒的旋转角大致相同;最后,对底火上多个击痕的图像进行处理得到其整体轮廓,并解算出该轮廓的最小外接圆半径。轮廓最小外接圆半径与单个击痕圆半径之差即为火炮击针偏心度。采用蒙特卡洛方法仿真结果表明:新方法不受药筒旋转的转角误差和击针偏心度大小的影响,测量均方差数值稳定。仿真结果验证了该方法的可行性和有效性。     

基于改进Markov模型软件测试策略

针对已有软件测试Markov模型与工程实践不符的情况,通过引入软件需求覆盖率改进Markov模型。在改进的Markov模型基础上,本文以软件测试过程中测试总代价最小为控制目标,采用交叉熵方法修正测试剖面,由优化测试剖面生成测试用例序列。仿真结果表明这种方法能够有效地降低软件测试总代价,是一种有效的软件测试方法。     

An MX/G/1 queueing system with disasters and repairs under a multiple adapted vacation policy

We consider a queueing system with batch Poisson arrivals subject to disasters which occur independently according to a Poisson process but affect the system only when the server is busy, in which case the system is cleared of all customers. Following a disaster that affects the system, the server initiates a repair period during which arriving customers accumulate without receiving service. The server operates under a Multiple Adapted Vacation policy. The stationary regime of this process is analyzed using the supplementary variables method. We obtain the probability generating function of the number of customers in the system, the fraction of customers who complete service, and the Laplace transform of the system time of a typical customer in stationarity. The stability condition for the system and the Laplace transform of the time between two consecutive disasters affecting the system is obtained by analyzing an embedded Markov renewal process. The statistical characteristics of the batches that complete service without being affected by disasters and those of the partially served batches are also derived. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 171–189, 2015     

多品种空投小件装载优化建模研究

针对空投小件装载率低下的现状,提出利用相关容重比平衡法,制定装载计划以充分利用飞机的载重能力及其使用面积,分别建立了单机和多机空投小件装载模型。该模型充分考虑了飞机的面积和载重量,对提高空投小件装载的利用率,起到良好应用效果。     

Tests for homogeneity of distributions of component lifetimes from system lifetime data with known system signatures

In this article, we discuss the problem of testing the homogeneity of distributions of component lifetimes based on system lifetime data when the system signatures are known. Both parametric and nonparametric procedures are developed for this problem. For nonparametric testing, the Mann–Whitney‐type statistic is used, and its performance and limitations are discussed. Next, we assume the component lifetimes to follow exponential distributions and then develop different parametric tests. Exact and asymptotic methods are developed based on the method of moments estimators. A Monte Carlo simulation study is used to compare the performance of different parametric procedures with that of the nonparametric procedure. Based on the results of the simulation study, discussions and practical recommendations are made and finally some concluding remarks are provided. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 550–563, 2015     

新装备故障分析与判定方法探讨

介绍了“新装备故障分析与判定方法”,提出了用逻辑分析的方法分析产生故障的可能原因.重点分析故障的特征与检查判定方法,拟定故障的诊断程序应遵循的原则,并结合××坦克主离合器踏板过重的故障模式进行了实例分析.     

铁红—酚醛船底漆中缓蚀剂的研究

在铁红—酚醛船底漆中,加入一种羧酸类化合物或一种肟类化合物作为涂层缓蚀剂,经电化学方法评定,证明它们在3％的NaCl溶液中的耐蚀性能,较之未加缓蚀剂的涂装钢样均有不同程度的提高。     

一种火力毁伤效能评估方法

Lanchester方程和Monte Carlo方法是作战模拟的常用方法,前者按取均值的方法处理作战过程,忽略了各种因素随时间的差异性,降低了模拟精度;后者对细节的要求较高,使问题变得复杂难解。结合两种方法,既充分考虑了作战问题的宏观规律性和局部共性,也顾及了其中关键因素的微观差异性和随机性,在火力毁伤效能模拟评估问题的应用研究中有较好的表现。     

Non‐zero‐sum nonlinear network path interdiction with an application to inspection in terror networks

A simultaneous non‐zero‐sum game is modeled to extend the classical network interdiction problem. In this model, an interdictor (e.g., an enforcement agent) decides how much of an inspection resource to spend along each arc in the network to capture a smuggler. The smuggler (randomly) selects a commodity to smuggle—a source and destination pair of nodes, and also a corresponding path for traveling between the given pair of nodes. This model is motivated by a terrorist organization that can mobilize its human, financial, or weapon resources to carry out an attack at one of several potential target destinations. The probability of evading each of the network arcs nonlinearly decreases in the amount of resource that the interdictor spends on its inspection. We show that under reasonable assumptions with respect to the evasion probability functions, (approximate) Nash equilibria of this game can be determined in polynomial time; depending on whether the evasion functions are exponential or general logarithmically‐convex functions, exact Nash equilibria or approximate Nash equilibria, respectively, are computed. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 139–153, 2017