具分布时滞的广义系统周期解的存在性

研究了一类具分布时滞的广义系统模型,用矩阵测度和Krasnoselskii不动点定理获得了其周期解存在的若干充分条件,并举例说明其应用.     

若干有偏估计的强影响点的显著性检验

本文首次研究线性模型中有偏估计的强影响点的显著性检验。通过后验分布对数似然函数,本文求出了检验岭估计、广义岭估计和Stein估计的强影响点的Score检验统计量,并用实例说明同一组数据对不同估计的影响的差异。     

长方体上均匀分布的密度函数

讨论了长方体上均匀分布密度函数问题,得到了长方体体积的估计量、估计量的点估计及估计量的密度函数.     

至多一个分布变点的非参数统计推断

本文研究了连续分布函数变点的非参数统计推断问题.利用秩统计量和次序统计量,获得了变点的一种估计,不仅论证了点估计的强相合性,而且讨论了假设检验和区间估计.     

Path-dependent estimation of a distribution under generalized censoring

This paper focuses on the problem of estimating a bivariate distribution when the data points are subject to censoring by a general class of randomsets. A path-dependent estimator for the distribution is proposed. The estimator is sequential in the sense that at any fixed point, it depends only on the data preceding the point. If the censoring mechanism is totally ordered, the paths may be chosen in such a way that the estimate of the distribution is an increasing function. In this case, a functional central limit theorem is proven for the estimator. Applications are discussed, and the validity of bootstrap methods is established.     

学习水平的标准评价模型及应用

提出了一个标准分数系统,给出了标准分数变换公式.该系统将学生的成绩分布转换为一个后验确定参数的正态分布,以后验地修复由试题差异和其他考试环境引起的分数分布异常波动,最大限度的提高了标准分数的区分度,也使该分布更接近学生学习水平的实际分布.在此基础上讨论了该标准化分数系统在学生学习水平的比较,试卷的评估等方面的应用.     

产品失效率的验前分布稳健性分析

研究Bayes统计分析中利用验前信息的稳健性.首先,用一般方法研究了指数寿命型分布中失效率的验前分布的稳健性.然后利用Gamma分布函数的典型性质,并以平方损失下的后验期望损失为判别准则,讨论了失效率的最优Bayes稳健区间.给出了失效率的最优Bayes稳健点估计.     

并联压力—强度模型可靠性研究

In this paper,the reliability of a parallel stress-strength model of exponentiated Pareto distribution is discussed.Different point estimations and interval estimations are proposed.The point estimators obtained are maximum likelihood and Bayesian estimators.The interval estimations obtained are approximate,exact,bootstrap-p and bootstrap-t confidence intervals and Bayesian credible interval.Different methods and the corresponding confidence intervals are demonstrated using some simulation studies.     

二项分布的参数估计问题研究

本文主要讨论二项分布的参数估计问题.对GB/T 4087.1-1983,GB/T 4087.2-1983,GB/T4087.3-1985给出的经典二项分布参数点估计、区间估计和可靠度置信下限计算方法进行了分析,指出了其中存在的问题.根据二项分布的数学表达式推导出了二项分布参数的概率分布密度函数,在此基础上提出了进行二项分布参数估计的一般方法.     

一类五次微分系统的定性分析

对一类五次平面多项式微分系统进行了定性分析.给出原点的中心与等时中心条件及极限环的存在性.研究了此系统无穷远点的性态,该无穷远点是高次奇点,并运用把大角域分为若干小角域的方法对此高次奇点在不定号情形下轨线的分布情况进行讨论.     

Burr Type XII 分布的统计推断

该文讨论了两参数 Burr Type XII 分布基于逐次定数截尾样本的参数估计, 导出了有关参数的点估计和区间估计. 我们利用模拟方法对所给点估计和参数的最大似然估计作了比较, 模拟结果显示所给点估计优于常用的最大似然估计. 最后, 用一个实际例子说明本文所给方法.     

Distribution planning in a turbulent environment

This paper looks at planning within the present distribution environment, paying particular attention to recent trends and developments. The idea of a depot as the traditional building block of a distribution network is questioned and the various functions of a regional depot are explored.The concept of a transit point as a simple alternative to a depot is developed and examples are given of its use in practice. Several refinements are available, particularly in the area of trailer technology, and these are discussed. The necessary support system for transit point operation is identified and finally the implications for distribution planning are considered.     

TRANSIENT SOLUTION FOR QUEUE-LENGTH DISTRIBUTION OF Geometry/G/1 QUEUEING MODEL

In this paper, the Geometry/G/1 queueing model with inter-arrival times generated by a geometric（parameter p） distribution according to a late arrival system with delayed access and service times independently distributed with distribution {gj }, j≥ 1 is studied. By a simple method （techniques of probability decomposition, renewal process theory） that is different from the techniques used by Hunter（1983）, the transient property of the queue with initial state i（i ≥ 0） is discussed. The recursion expression for u -transform of transient queue-length distribution at any time point n^＋ is obtained, and the recursion expression of the limiting queue length distribution is also obtained.     

Some properties of the bivariate lognormal distribution for reliability applications

In this paper, we study the bivariate lognormal distribution from a reliability point of view. The conditional distribution of X given Y > y is found to be log‐skew normal. The monotonicity of the hazard rates of the univariate as well as the conditional distributions is discussed. Clayton's association measure is obtained in terms of the hazard gradient, and its value in the case of our model is derived. The probability distributions, in the case of series and parallel systems, are derived, and the monotonicity of their failure rates is discussed. Three real applications of the bivariate lognormal distribution are provided, two from financial economics and one from reliability. Copyright © 2012 John Wiley & Sons, Ltd.     

U型波纹壳轴对称大挠度非线性变形问题(Ⅱ)——计及壁厚分布的变化

在文[1]基础上,假设U型波纹壳子午线上任一点处壁厚的对数与该点到对称轴距离的对数成线性关系,给出了相应的轴对称大挠度问题的摄动解,讨论了由工艺因素引起的壁厚分布的变化对波纹壳刚度的影响.     

带两类服务的一般休假M/GI/1型系统的随机分解

借助于建立在平稳点过程和Palm分布理论基础上的强度保守原理,讨论了一个具有一般休假策略的M/GI/1型排队系统.该模型允许闲期中顾客非泊松到达且顾客的服务可以被休假中断。我们得到了稳态下工作量和顾客离去前所见队长的随机分解.     

指数寿命定时截尾数据情形下可靠度的置信限

本文提供了一种指数寿命定时截尾寿命试验数据情形下参数的点估计方法,并在该点估计的基础上,利用Winterbottom[1]推广了的Cornish－Fisher（记为WCF）展开给出了参数的区间估计．进一步讨论了部件为指数寿命定时截尾寿命试验数据情形下系统可靠性综合问题,并通过数值模拟说明本文方法的可行性．     

Power laws behavior in multi-state elastic models with different constraints in the statistical distribution of elements

Often materials exhibit nonlinearity and hysteresis in their response to an elastic excitation and the dependence of the nonlinear indicator on the excitation energy is a power law function. From the theoretical point of view, such behavior could be described using multistate elastic models based on a generalized Preisach–Mayergoyz (PM) approach. In these models a statistical distribution of transition parameters is usually introduced. We show in this paper the existence of a link between the power law exponent predicted by the model and the properties of the chosen distribution. Numerical results are discussed, based on an implementation in the PM formalism of an adhesion model.     

Statistical Analysis Technique of Two-parameter Generalized Exponential Sum Distribution

A new life distribution is proposed, known as ``two-parameter generalized exponential sum distribution". We study the density function and failure rate function, the average failure rate function, the image features and the numerical characteristics of the mean residual life of the distribution. Several methods of calculating point estimation of parameters are discussed. Through the Monte-Carlo simulation, we compare the precision of the point estimations. In our opinion, the best linear unbiased estimation is the most optimal solution of these methods. At the same time, several methods of calculating parameters of interval estimations are given. We also discuss the precision of interval estimations by Monte-Carlo simulation and use the best linear unbiased estimation and the best linear invariant estimation to construct interval estimations which are better than other estimation method. Finally, several simulation examples and a case of maintaining tanks is used to illustrate the application of the methods presented in this paper.