Empirical Bayes Test for Two-parameter Exponential Distribution under Type-Ⅱ Censored Samples

The empirical Bayes test problem is considered for scale parameter of twoparameter exponential distribution under type-II censored data.By using wavelets estimation method,the EB test function is constructed,of which the asymptotic optimality and convergence rates are obtained.Finally,an example concerning the main result is given.

BAYESIAN PREDICTION FOR THE TWO-PARAMETER EXPONENTIAL DISTRIBUTION BASED ON TYPE Ⅱ DOUBLY CENSORING

The two-parameter exponential distribution is proposed to be an underlying model,and prediction bounds for future observations are obtained by using Bayesian approach.Prediction intervals are derived for unobserved lifetimes in one-sample prediction and two-sample prediction based on type Ⅱ doubly censored samples.A numerical example is given to illustrate the procedures,prediction intervals are investigated via Monte Carlo method,and the accuracy of prediction intervals is presented.

Prediction of nuclear charge density distribution with feedback neural network

Nuclear charge density distribution plays an important role in both nuclear and atomic physics,for which the two-parameter Fermi(2pF)model has been widely applied as one of the most frequently used models.Currently,the feedforward neural network has been employed to study the available 2pF model parameters for 86 nuclei,and the accuracy and precision of the parameter-learning effect are improved by introducing A^(1∕3)into the input parameter of the neural network.Furthermore,the average result of multiple predictions is more reliable than the best result of a single prediction and there is no significant difference between the average result of the density and parameter values for the average charge density distribution.In addition,the 2pF parameters of 284(near)stable nuclei are predicted in this study,which provides a reference for the experiment.

Interval Estimation in a Two Parameter Weibull Distribution Based on Type-2 Censored Data

In this paper, we consider the construction of the approximate profile- likelihood confidence intervals for parameters of the 2-parameter Weibull distribution based on small type-2 censored samples. In previous research works, the traditional Wald method has been used to construct approximate confidence intervals for the 2-parameter Weibull distribution under type-2 censoring scheme. However, the Wald technique is based on normality assumption and thus may not produce accurate interval estimates for small samples. The profile-likelihood and Wald confidence intervals are constructed for the shape and scale parameters of the 2-parameter Weibull distribution based on simulated and real type-2 censored data, and are hence compared using confidence length and coverage probability.

Statistical Analysis of Two-Parameter Generalized BS-Logistic Fatigue Life Distribution

The logarithmic moment estimations of parameters are proposed for two-parameter generalized Birnbaum-Saunders Logistic fatigue life distribution GBS-Logistic(α,β)under the full sample.The precisions of point estimations are investigated and compared with other point estimations by Monte-Carlo simulations.The approximate interval estimations of parameters are given by using Taylor expansion,and the precisions of approximate interval estimations are investigated by Monte-Carlo simulations.Finally,several examples show the feasibility of the methods.

基于威布尔分布的舰船装备故障分析

传统的舰船故障分析多由早期故障期、偶然故障期和耗损故障期三阶段的故障分布组合而成,没有统一的数学表达式。统计表明现代舰船大量装备不存在耗损故障期。为了满足舰船故障分析的需要,提出基于二参数的威布尔函数的故障率分布,并对该分布进行了卡方检验,结果表明威布尔分布能很好的描述舰船装备的故障率。

机制砂混凝土抗弯曲疲劳性能研究

开展了机制砂混凝土(MSC)与河砂混凝土(RSC)在5种应力水平下的等幅弯曲疲劳试验,进行了混凝土弯曲疲劳寿命的Weibull分布检验,拟合了用于确定等幅荷载下弯曲疲劳寿命的SN-Pf方程,并对混凝土界面过渡区进行了显微分析.结果表明:MSC和RSC的弯曲疲劳寿命分布均符合两参数Weibull分布,MSC弯曲疲劳寿命离散性整体小于RSC;在相同应力水平下,MSC的抗弯曲疲劳性能优于RSC,且其弯曲疲劳寿命的应力水平变化敏感性小于RSC;弯曲疲劳寿命为2×106次时,MSC的弯曲疲劳强度折减系数为55%,RSC的弯曲疲劳强度折减系数为53%;MSC界面过渡区显微硬度大于RSC,且界面过渡区密实性更好.

基于寿命预测的水轮机最佳改造时间模型

在分析水轮机寿命和费用特征的基础上,确立了设备运行维护和修复费用分配,建立了基于威布尔分布的水轮机最佳使用寿命模型,提出基于水轮机寿命预测的设备改造策略,开展水轮机的可靠性研究和寿命预测,有助于提高水轮机运行、管理决策的科学性和水平。

多晶硅微悬臂梁断裂的可靠性预测模型

分析了多晶硅微悬臂梁断裂失效机理,利用威布尔分布理论建立了多晶硅微悬臂梁在轴向拉抻和垂直两种受力方式下的断裂可靠性预测模型,模型考虑了由于实际加工工艺所带来的残余应力因素,模型所得的预测曲线与实验数据比较吻合。

Average Life Prediction Based on Incomplete Data

The two-parameter exponential distribution can often be used to describe the lifetime of products for example, electronic components, engines and so on. This paper considers a prediction problem arising in the life test of key parts in high speed trains. Employing the Bayes method, a joint prior is used to describe the variability of the parameters but the form of the prior is not specified and only several moment conditions are assumed. Under the condition that the observed samples are randomly right censored, we define a statistic to predict a set of future samples which describes the average life of the second-round samples, firstly, under the condition that the censoring distribution is known and secondly, that it is unknown. For several different priors and life data sets, we demonstrate the coverage frequencies of the proposed prediction intervals as the sample size of the observed and the censoring proportion change. The numerical results show that the prediction intervals are efficient and applicable.

LBVW分布的Fisher信息矩阵

文本考察由Larry Lee提出的其生存函数为 F(x_1,x_2)=exp{-[(x_1/θ_1)^(1/αδ)]~δ} (x_i>0,θ_i>0,i=1,2;0<δ≤1,α>0)的LBVW(θ_1,θ_2,δ,α)分布的统计性质,该分布的Fisher信息矩阵被导出。

玄武岩纤维混凝土弯曲疲劳性能研究

对4种纤维掺量的玄武岩纤维混凝土试件在3种不同应力水平下进行三点弯曲疲劳试验,利用数理统计方法对疲劳试验数据进行了弯曲疲劳寿命的威布尔分布检验,并拟合了不同失效概率下的双对数疲劳方程。结果表明:玄武岩纤维混凝土的弯曲疲劳寿命均符合两参数威布尔分布,且随着应力水平的减小,威布尔形状参数先减少后增大,弯曲疲劳寿命离散性先增大后减小;随着纤维掺量的增加,混凝土的弯曲疲劳寿命分布更加均匀,离散性更小,疲劳寿命大幅度增加。

A fiducial argument for generalized p-value

This paper provides a general method for constructing generalized p-value via the fiducial inference.Furthermore,the power properties of the generalized test are discussed.As illustrations, the two-parameter exponential distribution and unbalanced two-fold nested design are researched.It is shown that the resulting generalized p-values are of good frequency property.