Confidence intervals for the mean of a normal distribution with restricted parameter space

For a normal distribution with known variance, the standard confidence interval of the location parameter is derived from the classical Neyman procedure. When the parameter space is known to be restricted, the standard confidence interval is arguably unsatisfactory. Recent articles have addressed this problem and proposed confidence intervals for the mean of a normal distribution where the parameter space is not less than zero. In this article, we propose a new confidence interval, rp interval, and derive the Bayesian credible interval and likelihood ratio interval for general restricted parameter space. We compare these intervals with the standard interval and the minimax interval. Simulation studies are undertaken to assess the performances of these confidence intervals.     

Connecting for success: Egocentric network types among underrepresented minority students at college

This study investigates the egocentric networks of underrepresented minority students. Adjustment to college for underrepresented minority students often means balancing between the origin (i.e., low-status family) and host (i.e., academic) environments, requiring students to develop different coping strategies. The analysis included 124 Roma university students. We employed the contact diary method and the EgoNet program for mapping students’ egocentric networks. We explored classification among egocentric networks by cluster analysis based on the network proportion of the origin, fellow, and host groups. Three clusters were distinguished. The Host-based cluster proved to be the most advantageous, while the Balancing cluster appeared to be the most disadvantageous in terms of network resources, well-being, and trust. Partners’ ethnicity and educational attainment showed a strong connection with cluster membership. Our results highlight that small fellow communities can successfully interconnect the origin and host groups in students’ egocentric networks.     

争国本：君臣博弈的政治解读

万历年间册立太子之争被称为＂争国本＂,围绕册立皇长子朱常洛还是皇三子朱常洵,明神宗万历与廷臣进行了旷日持久的博弈。整个事件由廷臣温和的建议开始,经过长期而激烈的斗争,以至于谣言四起,最后借助太后的力量得以解决,按祖制皇长子朱常洵被册立为太子,皇三子朱常洛受封福王。争国本是认识明朝政治运作的典型样本,折射了专制王朝政治运作的内在逻辑。     

从城市崇拜看阎连科的小说创作

阎连科出生在贫困的乡村,由于童年和少年时期的缺失性体验而产生一种向往城市的心理。这种心理在他的小说中体现为贫瘠土地上的青年农民拼命逃离土地、渴望进入城市的迫切心情。他的小说可以让人感受到主人公在逃离土地之路上挣扎的痛苦心声,同时也可体味到作者希冀精神上回归土地的殷切心情。     

Beyond the Preschool Years: Children’s Perceptions About Starting Kindergarten

This article describes a research study that investigated three‐ and four‐year‐old Canadian preschool children’s perceptions about starting kindergarten. Findings from 33 focus‐group discussions suggest that children begin to formulate ideas about starting kindergarten prior to school entry. Children’s responses were grouped according to three themes, play versus academic activities and homework; getting bigger but still needing help; and rules. Overall, the responses highlighted their expectations regarding continuity and discontinuity between the two environments. These findings support the position that children should be given the opportunity to contribute to the planning of transition practices.     

从俞平伯晚年自省和“李希凡自述”想到的(之三)——回应俞平伯晚年的红学研究反思

俞平伯先生晚年的红学自省是真实可信的,应引起红学界高度重视,他的红学研究思想的重大变化同1954年那场对他的批评有内在的因果关系。对当年那场"批俞评红"不能全盘否定,不能只讲负面问题,全面否定其正确性和必要性。现在红学研究的一些乱象正是当年批判过了的错误研究思想、研究方法的泛滥。这种泛滥同对当年的全盘否定不无关系。     

A new stratified three-stage unrelated randomized response model for estimating a rare sensitive attribute based on the Poisson distribution

This article suggests an efficient method of estimating a rare sensitive attribute which is assumed following Poisson distribution by using three-stage unrelated randomized response model instead of the Land et al. model (2011 Land, M., S. Singh, and S. A. Sedory. 2011. Estimation of a rare sensitive attribute using poisson distribution. Statistics 46 (3):351–60. doi:10.1080/02331888.2010.524300.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) when the population consists of some different sized clusters and clusters selected by probability proportional to size(:pps) sampling. A rare sensitive parameter is estimated by using pps sampling and equal probability two-stage sampling when the parameter of a rare unrelated attribute is assumed to be known and unknown.

We extend this method to the case of stratified population by applying stratified pps sampling and stratified equal probability two-stage sampling. An empirical study is carried out to show the efficiency of the two proposed methods when the parameter of a rare unrelated attribute is assumed to be known and unknown.     

Robustness to non-normality and autocorrelation of individuals control charts

This paper studies the effects of non-normality and autocorrelation on the performances of various individuals control charts for monitoring the process mean and/or variance. The traditional Shewhart X chart and moving range (MR) chart are investigated as well as several types of exponentially weighted moving average (EWMA) charts and combinations of control charts involving these EWMA charts. It is shown that the combination of the X and MR charts will not detect small and moderate parameter shifts as fast as combinations involving the EWMA charts, and that the performana of the X and MR charts is very sensitive to the normality assumption. It is also shown that certain combinations of EWMA charts can be designed to be robust to non-normality and very effective at detecting small and moderate shifts in the process mean and/or variance. Although autocorrelation can have a significant effect on the in-control performances of these combinations of EWMA charts, their relative out-of-control performances under independence are generally maintained for low to moderate levels of autocorrelation.     

Economic and economic statistical designs for three-level control charts

In some situations, an appropriate quality measure uses three or more discrete levels to classify a product characteristic. For these situations, some control charts have been developed based on statistical criteria regardless of economic considerations. In this paper, we develop economic and economic statistical designs (ESD) for 3-level control charts. We apply the cost model proposed by Costa and Rahim.[Economic design of X charts with variable parameters: the Markov chain approach, J Appl Stat 28 (2001), 875–885] Furthermore, we assume that the length of time that the process remains in control is exponentially distributed which allows us to apply the Markov chain approach for developing the cost model. We apply a genetic algorithm to determine the optimal values of model parameters by minimizing the cost function. A numerical example is provided to illustrate the performance of the proposed models and to compare the cost of the pure economic and ESD for three-level control charts. A sensitivity analysis is also conducted in this numerical example.     

On an asymptotic relative efficiency concept based on expected volumes of confidence regions

ABSTRACT

The paper deals with an asymptotic relative efficiency concept for confidence regions of multidimensional parameters that is based on the expected volumes of the confidence regions. Under standard conditions the asymptotic relative efficiencies of confidence regions are seen to be certain powers of the ratio of the limits of the expected volumes. These limits are explicitly derived for confidence regions associated with certain plugin estimators, likelihood ratio tests and Wald tests. Under regularity conditions, the asymptotic relative efficiency of each of these procedures with respect to each one of its competitors is equal to 1. The results are applied to multivariate normal distributions and multinomial distributions in a fairly general setting.