Generalized additive mixed models

Following the extension from linear mixed models to additive mixed models, extension from generalized linear mixed models to generalized additive mixed models is made, Algorithms are developed to compute the MLE's of the nonlinear effects and the covariance structures based on the penalized marginal likelihood. Convergence of the algorithms and selection of the smooth param¬eters are discussed.     

Diagnostics for elliptical linear mixed models with first-order autoregressive errors

For longitudinal time series data, linear mixed models that contain both random effects across individuals and first-order autoregressive errors within individuals may be appropriate. Some statistical diagnostics based on the models under a proposed elliptical error structure are developed in this work. It is well known that the class of elliptical distributions offers a more flexible framework for modelling since it contains both light- and heavy-tailed distributions. Iterative procedures for the maximum-likelihood estimates of the model parameters are presented. Score tests for the presence of autocorrelation and the homogeneity of autocorrelation coefficients among individuals are constructed. The properties of test statistics are investigated through Monte Carlo simulations. The local influence method for the models is also given. The analysed results of a real data set illustrate the values of the models and diagnostic statistics.     

Several nonparametric and semiparametric approaches to linear mixed model regression

Mixed models are powerful tools for the analysis of clustered data and many extensions of the classical linear mixed model with normally distributed response have been established. As with all parametric (P) models, correctness of the assumed model is critical for the validity of the ensuing inference. An incorrectly specified P means model may be improved by using a local, or nonparametric (NP), model. Two local models are proposed by a pointwise weighting of the marginal and conditional variance–covariance matrices. However, NP models tend to fit to irregularities in the data and may provide fits with high variance. Model robust regression techniques estimate mean response as a convex combination of a P and a NP model fit to the data. It is a semiparametric method by which incomplete or incorrectly specified P models can be improved by adding an appropriate amount of the NP fit. We compare the approximate integrated mean square error of the P, NP, and mixed model robust methods via a simulation study and apply these methods to two real data sets: the monthly wind speed data from countries in Ireland and the engine speed data.     

高校学报混刊问题探讨

我国高校学报目前实行规模狭小的办刊方式、自我封闭的管理模式以及条块分割的管理体制,难以形成规模效应和品牌优势。为了解决学校教师发表文章的困难,某些专业刊物中夹杂着不同学科的论文。文章分析了这种现象的影响及解决对策。     

An Orthogonality‐Based Estimation of Moments for Linear Mixed Models

Abstract. Estimating higher‐order moments, particularly fourth‐order moments in linear mixed models is an important, but difficult issue. In this article, an orthogonality‐based estimation of moments is proposed. Under only moment conditions, this method can easily be used to estimate the model parameters and moments, particularly those of higher order than the second order, and in the estimators the random effects and errors do not affect each other. The asymptotic normality of all the estimators is provided. Moreover, the method is readily extended to handle non‐linear, semiparametric and non‐linear models. A simulation study is carried out to examine the performance of the new method.     

社会转型期领导者能力新框架的构建

在社会转型期,各种竞争日益激烈.领导者们既要正视竞争,更应珍惜竞争的机会.只要对自己的管理才能进行大胆挖掘,全方位修构,便能抓住竞争的机遇,找到自我与组织生存和发展的空间.     

多孔介质中可压缩混溶驱动问题的特征：混合元方法

本文考虑二维一般有界区域中的多孔介质同可压缩混溶动问题的数值解方法，给出了全离散特征－混合元格，证明了格式的唯一可解性，得到最佳Ｈ－模误差估计。     

Conceptual Framework of Coalitions in an Organizational Context

Summary

Organizations are forming coalitions in their struggle to survive with fewer resources. Under the “Contract With America,” funds for human services are expected to be increasingly cut back. Organizational actors will continue to coalesce because of their compelling interests to serve disadvantaged populations in our communities. This article uses the political-economy perspective in presenting a conceptual framework of coalitions in organizational settings. We need access to various perspectives and models of coalition building in order to provide direction for organizational groups as they attempt to change the sociopolitical structures in which they must operate.     

二美杂会还是洁秽相混？——屈赋“芳泽杂糅”诸句释意简析

对屈原《离骚》等作品中的"芳与泽其杂糅兮"诸句,古今学者的解释存在分歧和矛盾。本文支持王逸以来释"芳与泽"为芳香与润泽的观点,并分析了解"泽"作与"芳"相对的污秽、垢腻之类义项的释意的错误原因,指出其思路与前提本不确当,可以视为读懂古书、解决某些字句训释分歧时应吸取的经验教训。     

Tests and Confidence Intervals for an Extended Variance Component Using the Modified Likelihood Ratio Statistic

Abstract.  The large deviation modified likelihood ratio statistic is studied for testing a variance component equal to a specified value. Formulas are presented in the general balanced case, whereas in the unbalanced case only the one-way random effects model is studied. Simulation studies are presented, showing that the normal approximation to the large deviation modified likelihood ratio statistic gives confidence intervals for variance components with coverage probabilities very close to the nominal confidence coefficient.