Estimation of a multivariate mean with constraints on the norm

Estimation of the mean θ of a spherical distribution with prior knowledge concerning the norm ||θ|| is considered. The best equivariant estimator is obtained for the local problem ||θ|| = λ₀, and its risk is evaluated. This yields a sharp lower bound for the risk functions of a large class of estimators. The risk functions of the best equivariant estimator and the best linear estimator are compared under departures from the assumption ||θ|| = λ₀.     

一类刚性系统基于线性多步法的并行计算方法

针对一类分解的刚性系统,提出了一类并行组合方法.该方法将系统分割与方法分割的并行化方法相结合,采用显式线性多步方法求解非刚性子系统,采用隐式线性多步方法求解刚性子系统.讨论了方法的相容阶、收敛性和数值稳定性.数值试验结果表明,该方法对于求解分解的刚性系统是可行的.     

A general lower bound of minimax risk for absolute-error loss

A general lower bound of minimax risk for absolute-error loss is given in terms of the Hellinger modulus of the estimation problem. The main results are applicable to various parametric, semi-parametric and nonparametric problems. Two examples of parametric estimation problems and two examples of density estimation problems are given. In all of these examples, the general lower bound achieves the convergence rates of minimax risk.     

Confidence Intervals for Intraclass Correlation in Inter-Rater Reliability

Abstract Calculation of a confidence interval for intraclass correlation to assess inter‐rater reliability is problematic when the number of raters is small and the rater effect is not negligible. Intervals produced by existing methods are uninformative: the lower bound is often close to zero, even in cases where the reliability is good and the sample size is large. In this paper, we show that this problem is unavoidable without extra assumptions and we propose two new approaches. The first approach assumes that the raters are sufficiently trained and is related to a sensitivity analysis. The second approach is based on a model with fixed rater effect. Using either approach, we obtain conservative and informative confidence intervals even from samples with only two raters. We illustrate our point with data on the development of neuromotor functions in children and adolescents.     

试论文献检索与情报检索的界域差异

从研究文献与情报的概念和界域差异着眼 ,分析了文献检索与情报检索的界域区别 ,以便于提高检索效率和信息的利用率     

《诗经》对中国人的影响和中文学的熏沐

《诗经》不仅是我国最早的诗歌总集,也是中国文学的奠基石与第一座里程碑,更以其特有的思想、文化意蕴为后世中国文学艺术确立了一种纪元般的范式：“风”蕴含的生活之“真”,“雅”昭告的典范之“美”,“颂”彰显的伦理之“善”,均被后代的统治者用作教化人心、改善民风的圭臬。诗虽有“六义”,但真正对社会的发展和人性的向善起到关键作用的是“美刺比兴”,此由白居易身体力行,后代作家和学者又将其发扬光大。历时地考察各个朝代对“美刺比兴”的接受,正是汉斯·罗伯特·姚斯所谓“垂直接受”方法在“诗经学”研究中的一种合理运用,而在对每个历史时期以及具体的接受者进行考量时,则需要对其中的历史时间和这位接受者所处的社会空间加以辨析,这又是曼弗雷德·瑙曼提出“接受约束”概念时所关注的问题,他的研究方法同样值得借鉴。本文拟从社会学、政治学、伦理学等角度出发,对《诗经》施加于后世文学的影响进行剖析,再结合当下社会的发展要旨给予综合评说,以期为传统文化的递嬗承接提供参照,为中华民族的伟大复兴献策助力。     

Parameter estimation and prediction of order statistics for the Burr Type XII distribution with Type II censoring

This article deals with the statistical inference and prediction on Burr Type XII parameters based on Type II censored sample. It is observed that the maximum likelihood estimators (MLEs) cannot be obtained in closed form. We use the expectation-maximization algorithm to compute the MLEs. We also obtain the Bayes estimators under symmetric and asymmetric loss functions such as squared error and Linex By applying Lindley's approximation and Markov chain Monte Carlo (MCMC) technique. Further, MCMC samples are used to calculate the highest posterior density credible intervals. Monte Carlo simulation study and two real-life data-sets are presented to illustrate all of the methods developed here. Furthermore, we obtain a prediction of future order statistics based on the observed ordered because of its important application in different fields such as medical and engineering sciences. A numerical example carried out to illustrate the procedures obtained for prediction of future order statistics.     

An Improvement of Poisson Approximation for Sums of Dependent Bernoulli Random Variables

This article uses the Stein-Chen method to obtain new non uniform bounds on the error of the cumulative distribution function of sums of dependent Bernoulli random variables and the Poisson cumulative distribution function. The bounds obtained in the present study are sharper than those reported in Teerapabolarn and Neammanee (2006 Teerapabolarn, K., Neammanee, K. (2006). Poisson approximation for sums of dependent Bernoulli random variables. Acta Mathematica Academiae Paedagogicae Nyiregyhaziensis. 22:87–99. [Google Scholar]). Examples are provided to illustrate applications of the obtained results.