Inference on Overlap for Two Inverse Gaussian Populations: Equal Means Case

The inverse Gaussian distribution is often suited for modeling positive and/or positively skewed data (see Chhikara and Folks, 1989 Chhikara , R. S. , Folks , J. L. ( 1989 ). The Inverse Gaussian Distribution . New York : Marcel Dekker . [Google Scholar]) and presents an interesting alternative to the Gaussian model in such cases. We note here that overlap coefficients and their variants are widely studied in the literature for Gaussian populations (see Mulekar and Mishra, 1994 Mulekar , M. , Mishra , S. N. ( 1994 ). Overlap coefficients of two normal densities: equal means case . J. Japan. Statist. Soc. 24 : 169 – 180 . [Google Scholar], 2000 Mulekar , M. , Mishra , S. N. ( 2000 ). Confidence interval estimation of overlap: equal means case . Computat. Statist. Data Anal. 34 : 121 – 137 .[Crossref], [Web of Science ®] , [Google Scholar], and references therein for further details). This article studies the properties and addresses point estimation for large samples of commonly used measures of overlap when the populations are described by inverse Gaussian distributions. The bias and mean square error properties of the estimators are studied through a simulation study.     

Minimum average risk estimators for coefficients in linear models

We consider the problem of estimating the coefficient vector β of a linear regression model with quadratic loss function. Some biased estimators which utilize the prior information about β are considered. Also studied is the problem of estimating the parameters of an over-identified structural equation from undersized samples.     

An Empirical Study of Statistical Properties of Variance Partition Coefficients for Multi-Level Logistic Regression Models

Partitioning the variance of a response by design levels is challenging for binomial and other discrete outcomes. Goldstein (2003 Goldstein , H. ( 2003 ). Multilevel Statistical Models. 3rd ed . London : Edward Arnold . [Google Scholar]) proposed four definitions for variance partitioning coefficients (VPC) under a two-level logistic regression model. In this study, we explicitly derived formulae for multi-level logistic regression model and subsequently studied the distributional properties of the calculated VPCs. Using simulations and a vegetation dataset, we demonstrated associations between different VPC definitions, the importance of methods for estimating VPCs (by comparing VPC obtained using Laplace and penalized quasilikehood methods), and bivariate dependence between VPCs calculated at different levels. Such an empirical study lends an immediate support to wider applications of VPC in scientific data analysis.     

中国古代墓志形制变迁中的设计思想内蕴

以中国历代墓志形制与文体变化为纵向轴，一是以魏晋南北朝中的“志”“碑”合一形式以及宋齐梁陈中出现的简单化的墓志形式，论述了中国古代墓志设计的“实用”思想；二是以历代墓志文体演变为研读对象，系统论述了墓志文体设计演变中的“实用”与“浮华”的转变。系统考察中国历代墓志的形制与文体设计，墓志作为随葬风俗的一部分，其形制变化基本轨迹还是以实用为美、为尚。浮华的特质在重葬、经济允许的情况下，尤其是墓志志文成为文化人施展才华的载体之际，文体适应了为死者“歌颂”的普世之需，同时也体现了设计“应需而变”的设计本质。     

一类变系数边值问题的样条解法

本文讨论了一类三阶变系数微分方程的边值问题的样条解法．构造了一个四次样条的近似解,并证明了它的唯一性和收敛性．在文末举例说明本方法是可行的．     

平等权的存在形态及其内涵

现代平等权已经从道德形态演进为权利形态,成为宪法上的一项基本人权,其本质是对每一个个体的平等人格的尊重。平等权具有明确的、独特的权利内涵,核心部分包括禁止歧视和反对特权。现实生活中我国的不平等现象屡见不鲜,需要从意识更新和制度建构两方面入手,重构平权社会。     

Testing the monotonicity or convexity of a function using regression splines

Methods for smoothed isotonic or convex regression are useful in many applications. Sometimes the shape assumptions constitute a priori knowledge about the regression function, but often the shape is part of the research question. The authors propose tests for monotonicity and convexity using constrained and unconstrained regression splines. The tests have good large‐sample properties and the small‐sample behaviour is illustrated through simulations. Extensions to the partial linear model and the generalized regression model are presented. The Canadian Journal of Statistics 39: 89–107; 2011 © 2011 Statistical Society of Canada     

Logistic模型的系数比较问题及解决策略：一个综述

本文介绍了Logistic模型中经常被忽视的系数比较问题,包括同一样本在不同模型间的系数比较和在不同样本或子群体间的模型系数比较。研究者往往会沿袭线性回归模型的系数比较方法,但这是不恰当的,因为Logistic模型存在未被观测到的异质性（残差变异）问题,所以模型间系数不能进行简单的直接比较。根据已有研究,本文总结了解决这一问题的五种策略,分别是“y*标准化”、KHB分解、异质选择模型、平均偏效应（APE）和线性概率模型（LPM）,然后利用CGSS2006数据,以教育递进率模型为例,比较这些解决策略的异同,最后总结这些策略的特征及适用情况。     

Inhomogeneous Markov Chains and Ergodicity Coefficients: John Hajnal (1924–2008)

In 1958, a paper by John Hajnal, a demographer and mathematical statistician, was fundamental in the revival of the theory of inhomogeneous Markov chains. Hajnal made his contribution by the development of tools for the analysis of weak ergodicity, and proofs of fundamental theorems. This article reviews Hajnal's career, and then focuses on the four topics: 1. ergodicity coefficients and the weak ergodicity theorem; 2. scrambling matrices; 3. the coupling theorem; and 4. non-negative matrix products. Related work by other authors, especially Wolfgang Doeblin, is mentioned in context. Attention is given to some recent surveys and applications of ergodicity coefficients, including the Google matrix.