CE模型下Weibull分布序加试验的Bayes分析

序进应力加速寿命试验是一种最为有效而经济的寿命试验方法,随着其理论的日趋成熟,在实践中开始得到应用和推广．本文给出了逆幂律模型下Weilbull分布定时和定数场合序进应力加速寿命试验的一种Bayes统计分析,并利用Gibbs抽样方法解决了分布的形状参数取为连续先验时各参数的Bayes估计．这种先验意义更明确,实例表明这是一种非常有效的方法．     

由 Weibull 子系统数据综合的系统可靠度的置信下界限

§1.前言以往对系统可靠度的置信区间估计方法,主要是利用各个子系统的寿命试验的数据,通过系统的可靠性结构模型,进行可靠性综合的方法来得到系统可靠度的置信区间估计.关于这方面的若干情况可参阅文章[1]的概况介绍.从所查阅到的文献来看,主要是各子系统的寿命试验数据为成败型的或是指数分布类型的情况,至于各子系统的寿命分布是Weibull 分布的情况的文章较少,主要原因是,问题解决的困难和计算上产生的困难等,甚至于无法计算,不得不采用 Monte-Carlo 方法.本文中所讨论的问题,是 Weibull 子系统的情况,其方法的计算困难程度可以得到改善.     

残余寿命熵的上界

讨论寿命分布混合的类不变性问题,改进了文[1]中的相关结果.此外,基于寿命分布类的特性研究了不同于[4]的另一类残余寿命熵的特性,并在一定的条件下得到残余寿命熵的上界.     

用步进应力加速寿命试验法分析爆炸螺栓的可靠性

本文通过对爆炸螺栓进行步进应力加速寿命试验分析 ,得到爆炸螺栓可靠寿命的估计 ,从而确定爆炸螺栓的可靠性     

振动钻削微小孔中钻头寿命与振动参数的二次回归试验研究

本文采用正交组合设计的试验方法，对振动钻削微小孔加工中钻头寿命与轴向振动参数之间的非线性关系进行了二次回归试验，得到了最优回归方程。用回归方程给出的最佳振动参数钻孔，钻头寿命提高了９６．３％     

几何分布的参数估计及EM算法

几何分布是很重要的一种离散型寿命分布.通过添加缺损的寿命变量数据,得到完全数据的似然函数,进而利用EM算法,进行了随机模拟,得到的结果表明精确度较高,误差较小.     

指数分布场合恒加试验缺失数据的Bayes统计分析

主要讨论了当寿命分布是指数分布时恒定应力加速寿命试验中常见几类数据类型(完全样本,分组样本,删失样本)的Bayes统计分析方法.运用G ibbs抽样迭代算法成功解决了Bayes分析中极为复杂的后验边际分布的计算问题,得到了满足顺序约束的参数的Bayes估计.模拟结果表明各场合下此方法均较好.     

截尾子样下的检验方法在可靠性中的应用

<正> 由于产品可靠性日益提高,使用寿命不断延长,所以在寿命试验中,一般只能进行截尾试验,不易得到全子样数据,因而如何利用截尾数据对产品的寿命分布和有关参数进行假设检验,是可靠性数学问题中值得研究的课题.本文将讨论几种检验方法,并用实例说明这些方法在可靠性工程中的应用.     

多源验前信息下的Bayes信息融合方法

本文以指数分布寿命型电子产品为例,讨论了多源验前信息情况下如何对产品失效率进行融合估计的问题。首先,介绍了寿命试验数据的信息融合方法,并以此为例,说明了取伽玛分布为指数分布寿命型产品失效率的先验分布的合理性。然后,在产品具有多源验前信息源的情况下,给出了一种方便实用的Bayes信息融合方法,充分融合各验前信息,得到产品失效率的验前分布及后验分布。最后给出了数值实例。     

左截断右删失剩余寿命分位数的置信区间构造

在医学领域、可靠性分析和人寿保险市场中,剩余寿命是重要的研究范畴之一.因此,剩余寿命分位数区间的精确估计有着重要的意义.但是,在左截断和右删失同时存在的临床数据下,样本量通常很小,传统的置信区间构造方法多数不理想,而且涉及到的估计量方差的计算非常繁琐.为了避免上述困难,文章利用Jackknife-d方法构造了左截断右删失剩余寿命分位数的置信区间.同时,通过蒙特卡罗模拟和实例分析对Jackknife-d方法和传统的4种方法进行评价.模拟结果表明:小样本下,Jackknife-d方法得到的置信区间长度最短且覆盖率在大多数情况下都接近于名义水平,是剩余寿命分位数置信区间构造的一种很好的方法.     

Estimating a survival function with incomplete cause-of-death data

We propose a random censorship model which permits uncertainty in the cause of death assessments for a subset of the subjects in a survival experiment. A nonparametric maximum likelihood approach and a “self-consistency” approach are considered. The solution sets corresponding to both approaches are found. They are infinite and identical. Only some of the solutions are consistent; i.e., the MLEs and self-consistent estimators are not consistent in general. Two estimates are thus proposed and their asymptotic properties are studied. It is shown that both estimates are strongly consistent and converge to Gaussian processes. The covariance structures of these Gaussian processes are derived.     

Some properties of singular integral operators over an open curve Dedicated to the 85th birthday of Prof.Lu Jinake

In this paper, the stability properties, the endpoint behavior and the invertible relations of Cauchy-type singular integral operators over an open curve are discussed. If the endpoints of the curve are not special, this type of operators are proved to be stable. At the endpoints, either the singularity or smoothness of the operators are exactly described. And the function sets or spaces on which the operators are invertible as well as the corresponding inverted operators are given. Meanwhile, some applications for the solution of Cauchy-type singular integral equations are illustrated.     

Depth notions for orthogonal regression

Global depth, tangent depth and simplicial depths for classical and orthogonal regression are compared in examples, and properties that are useful for calculations are derived. The robustness of the maximum simplicial depth estimates is shown in examples. Algorithms for the calculation of depths for orthogonal regression are proposed, and tests for multiple regression are transferred to orthogonal regression. These tests are distribution free in the case of bivariate observations. For a particular test problem, the powers of tests that are based on simplicial depth and tangent depth are compared by simulations.     

Enumeration of point-determining graphs

Point-determining graphs are graphs in which no two vertices have the same neighborhoods, co-point-determining graphs are those whose complements are point-determining, and bi-point-determining graphs are those both point-determining and co-point-determining. Bicolored point-determining graphs are point-determining graphs whose vertices are properly colored with white and black. We use the combinatorial theory of species to enumerate these graphs as well as the connected cases.     

On the Geometry of Liouville Equation: Symmetries, Conservation Laws, and Bäcklund Transformations

Various geometrical structures related to the Liouville equation are considered. Properties of the symmetry algebra are discussed and local conserved currents are constructed. Bäcklund transformations for the Liouville equation are integrated and nontrivial generalizations of the latter are studied as well as the structures on them.     

Some properties of singular integral operators over an open curve Dedicated to the 85th birthday of Prof. Lu Jianke

In this paper, the stability properties, the endpoint behavior and the invertible relations of Cauchy-type singular integral operators over an open curve are discussed. If the endpoints of the curve are not special, this type of operators are proved to be stable. At the endpoints, either the singularity or smoothness of the operators are exactly described. And the function sets or spaces on which the operators are invertible as well as the corresponding inverted operators are given. Meanwhile, some applications for the solution of Cauchy-type singular integral equations are illustrated.     

On covering mappings on solenoids

Covering mappings on the dyadic solenoid are studied. Some results stated by Zhou Youcheng (2000) are discussed in a more detailed way by indicating certain inaccuracies in their proofs. These are either corrected or supplemented, or else suitable counterexamples are constructed. Some open questions are asked and connections with related results are considered.

     

凹角型区域椭圆边值问题的自然边界归化

In this paper, the natural boundary reduction for some elliptic boundary value problems with concave angle domains and their natural boundary methods are investigated. The natural integral equations and the Poisson integral formulae are given. The finite element methods of the natural integral equations are discussed in details. The convergences of the approximate solutions and their error estimates are obtained. Finally, some numerical examples are presented to show that our methods are effective.     

Some properties of complex matrix-variate generalized Dirichlet integrals

Dirichlet integrals and the associated Dirichlet statistical densities are widely used in various areas. Generalizations of Dirichlet integrals and Dirichlet models to matrix-variate cases, when the matrices are real symmetric positive definite or hermitian positive definite, are available [4]. Real scalar variables case of the Dirichlet models are generalized in various directions. One such generalization of the type-2 or inverted Dirichlet is looked into in this article. Matrix-variate analogue, when the matrices are hermitian positive definite, are worked out along with some properties which are mathematically and statistically interesting.     

Stability of random impulsive coupled systems on networks with Markovian switching

Abstract

This article is intended to study global asymptotical stability in probability for random impulsive coupled systems on networks with Markovian switching. Two cases are considered. (1) Continuous dynamics are stable while impulses are unstable; (2) impulses are stable while continuous dynamics are unstable. To begin with, based on Lyapunov method as well as graph-theoretic technique, several new stability criteria in two cases are derived, that are, the Lyapunov-type criteria and the coefficients-type criteria. Then main results are used for a class of random impulsive coupled oscillators. Finally, the effectiveness of the obtained results is verified by numerical simulations.