一种特殊的Wishart分布的密度函数

本文用积分变量替换的方法导出了一种特殊情形下的非中心Wishart分布密度函数的表达形式。     

关于五种常见的可测函数定义

列出了现今各种实变函数教材中五种常见的可测 函数的定义形式,通过对它们相互等价性的证明及一个实例的分析和几点评论,更加深入地 揭示了可测函数这一概念的内涵.     

一类局部紧的全不连通群上的加权Hardy－Bessel位势空间

从几个不同角度刻划了Vilenkin群上的加权Hardy-Bessel位势空间。     

上凸密度与Hausdorff测度—Koch曲线

探讨Koch曲线的Hausdorff测度与端点处的上凸密度之间的关系,利用Koch曲线的自相似性,证明了Koch曲线端点处的上凸密度小于1,并通过具体的数值计算,到它的1个上界。     

多维空间中点的密度与近似连续函数

给出可测集中点的密度的简单性质;推广一元近似连续函数到多元情形,得到可测函数与近似连续函数之间的关系。     

管状TB 上的解析函数

给出了2≤q≤+∞时管状Hq(TB)中的一类解析函数,并用新方法证明了Hp(TB0)中函数的一致有界性.     

几类函数的可测性判定

从可测函数的定义出发根据可测函数的判定方法,总结推导出复合函数,多元函数及幂指函数等函数的可测性的判定定理.     

Test selection and optimization for PHM based on failure evolution mechanism model

The test selection and optimization （TSO） can improve the abilities of fault diagnosis, prognosis and health-state evalua- tion for prognostics and health management （PHM） systems. Traditionally, TSO mainly focuses on fault detection and isolation, but they cannot provide an effective guide for the design for testability （DFT） to improve the PHM performance level. To solve the problem, a model of TSO for PHM systems is proposed. Firstly, through integrating the characteristics of fault severity and propa- gation time, and analyzing the test timing and sensitivity, a testability model based on failure evolution mechanism model （FEMM） for PHM systems is built up. This model describes the fault evolution- test dependency using the fault-symptom parameter matrix and symptom parameter-test matrix. Secondly, a novel method of in- herent testability analysis for PHM systems is developed based on the above information. Having completed the analysis, a TSO model, whose objective is to maximize fault trackability and mini- mize the test cost, is proposed through inherent testability analysis results, and an adaptive simulated annealing genetic algorithm （ASAGA） is introduced to solve the TSO problem. Finally, a case of a centrifugal pump system is used to verify the feasibility and effectiveness of the proposed models and methods. The results show that the proposed technology is important for PHM systems to select and optimize the test set in order to improve their performance level.     

点集的几个性质

本文定义了可化闭集和可化分离集的概念,并证明了R′中的有界点集E是有界可测的充要条件E是可化闭集,有界点集E是可测的充要条件E是可化分离集。