完善我国行政许可听证制度的思考

《行政许可法》中对听证制度的规定,使听证制度得到进一步发展。在分析该法规定的基础上,结合听证程序理论,评析了我国行政许可听证的立法现状,并有针对性地提出了相应的完善建议。     

Stage life testing

In progressive censoring, items are removed at certain times during the life test. Commonly, it is assumed that the removed items are used for further testing. In order to take into account information about these additional testing in inferential procedures, we propose a two‐step model of stage life testing with one fixed stage‐change time which incorporates information about both the removed items (further tested under different conditions) and those remaining in the current life test. We show that some marginal distributions in our model correspond either to progressive censoring with a fixed censoring time or to a simple‐step stress model. Furthermore, assuming a cumulative exposure model, we establish exact inferential results for the distribution parameters when the lifetimes are exponentially distributed. An extension to Weibull distributed lifetimes is also discussed.     

基于硬体拖靶的拖曳式干扰系统构建

战场复杂电磁环境对防空导弹提出了抗拖曳式干扰的新要求，在组织进行实际对抗效果飞行检验时，存在导弹威胁拖曳式诱饵载机安全的风险，影响试验的组织和决策。介绍了拖曳式干扰的系统组成、工作原理和实际使用问题，提出了基于现有硬体拖靶系统构建拖曳式干扰系统的方法，分析了拖曳式诱饵对拖靶系统飞行性能的影响。该构建方法可以有效解决困扰试验的安全问题，为后续系统的建设和试验提供参考。     

Pairwise model discrimination with applications in lifetime distributions and degradation processes

Reliability data obtained from life tests and degradation tests have been extensively used for purposes such as estimating product reliability and predicting warranty costs. When there is more than one candidate model, an important task is to discriminate between the models. In the literature, the model discrimination was often treated as a hypothesis test and a pairwise model discrimination procedure was carried out. Because the null distribution of the test statistic is unavailable in most cases, the large sample approximation and the bootstrap were frequently used to find the acceptance region of the test. Although these two methods are asymptotically accurate, their performance in terms of size and power is not satisfactory in small sample size. To enhance the small‐sample performance, we propose a new method to approximate the null distribution, which builds on the idea of generalized pivots. Conventionally, the generalized pivots were often used for interval estimation of a certain parameter or function of parameters in presence of nuisance parameters. In this study, we further extend the idea of generalized pivots to find the acceptance region of the model discrimination test. Through extensive simulations, we show that the proposed method performs better than the existing methods in discriminating between two lifetime distributions or two degradation models over a wide range of sample sizes. Two real examples are used to illustrate the proposed methods.     

薄壳变速箱壳体动态响应仿真分析与试验验证

在ADAMS（Automatic Dynamic Analysis of Mechanical Systems）中搭建薄壳箱体的刚柔耦合虚拟仿真模型，进行动态响应仿真分析。在相同试验条件下，搭建薄壳箱体动态响应试验台架，并进行动态振动试验。利用Q-400非接触式测试系统测量台架试验结果。对比仿真分析和试验测量结果，验证了仿真分析模型的准确性和计算结果的可靠性。     

某型车载导弹发射制导装置现场快速检测方法

某型装甲车载反坦克导弹系统的发射制导装置，集光、机、电多种技术于一体，技术状态易受装载、运输等因素的影响。在导弹射击前，一般应在现场对发射制导装置进行快速检测以确定其技术状态。为了解决现场快速检测问题，分析了该型导弹系统发射制导装置的结构和技术特点，确定了现场快速检测的内容：用点光源的电视图像检测两个光轴不平度；用电压比较法检测点火电压和点火程序正确性；用指令频率变化检测控制指令正确性。开发了适于现场快速检测的装置，为部队射击保障提供了一种决策支持方法。     

结构化装备型号需求论证模式研究

结构化是系统工程分析问题的重要手段。为给装备型号需求论证工程化提供理论依据与技术支撑,对结构化装备型号需求论证模式的相关问题进行了研究。分析了装备型号需求论证流程,界定了装备型号需求论证工作范围,明确了装备型号需求论证的内部流程和外部边界;针对一体化联合作战要求,提出了有指导性的需求论证策略,确保结构化装备型号需求论证模式的科学性;借鉴美军体系结构技术,构建了结构化装备型号需求论证空间,对整个论证空间的结构设计、论证域的划分和各论证环节的论证任务进行了深入研究,从技术角度实现了需求论证过程的结构化。     

引信湿热强化试验技术研究

针对传统引信湿热试验的缺点,以某型引信的电子头组件为研究对象,开展了引信的湿热强化试验技术研究。首先分析了湿热强化应力对缺陷的激发效果,即温度和湿度越高,对缺陷的激发效果越好。在此基础上,设计了湿热强化试验方案,并通过试验,暴露了电子头组件的薄弱环节,为提高其环境适应性奠定了基础,同时体现了湿热强化试验在激发引信潜在缺陷、缩短试验周期和降低试验费用方面的优势。还根据试验的反馈信息,对试验方案进行了优化。     

装备作战需求论证过程质量评估方法?

过程质量评估是装备作战需求论证质量评估的一项重要内容。在介绍装备作战需求论证过程基础上，提出了基于关键控制点的论证过程质量评估方法。采用判断树法确定四个关键控制点，建立了基于关键控制点的指标体系，采用神经网络法建立过程质量评估模型。最后进行了评估示例分析，结果表明该方法是可行的。     

Some new results on the preservation of the NBUE and NWUE aging classes under the formation of coherent systems

We consider the classical problem of whether certain classes of lifetime distributions are preserved under the formation of coherent systems. Under the assumption of independent and identically distributed (i.i.d.) component lifetimes, we consider the NBUE (new better than used in expectation) and NWUE (new worse than used in expectation) classes. First, a necessary condition for a coherent system to preserve the NBUE class is given. Sufficient conditions are then obtained for systems satisfying this necessary condition. The sufficient conditions are satisfied for a collection of systems which includes all parallel systems, but the collection is shown to be strictly larger. We also prove that no coherent system preserves the NWUE class. As byproducts of our study, we obtain the following results for the case of i.i.d. component lifetimes: (a) the DFR (decreasing failure rate) class is preserved by no coherent systems other than series systems, and (b) the IMRL (increasing mean residual life) class is not preserved by any coherent systems. Generalizations to the case of dependent component lifetimes are briefly discussed.