Testing equality of two normal covariance matrices with monotone missing data

Abstract

The problem of testing equality of two multivariate normal covariance matrices is considered. Assuming that the incomplete data are of monotone pattern, a quantity similar to the Likelihood Ratio Test Statistic is proposed. A satisfactory approximation to the distribution of the quantity is derived. Hypothesis testing based on the approximate distribution is outlined. The merits of the test are investigated using Monte Carlo simulation. Monte Carlo studies indicate that the test is very satisfactory even for moderately small samples. The proposed methods are illustrated using an example.     

Design selection for strong orthogonal arrays

Strong orthogonal arrays (SOAs) were recently introduced and studied as a class of space‐filling designs for computer experiments. An important problem that has not been addressed in the literature is that of design selection for such arrays. In this article, we conduct a systematic investigation into this problem, and we focus on the most useful SOA(n,m,4,2 + )s and SOA(n,m,4,2)s. This article first addresses the problem of design selection for SOAs of strength 2+ by examining their three‐dimensional projections. Both theoretical and computational results are presented. When SOAs of strength 2+ do not exist, we formulate a general framework for the selection of SOAs of strength 2 by looking at their two‐dimensional projections. The approach is fruitful, as it is applicable when SOAs of strength 2+ do not exist and it gives rise to them when they do. The Canadian Journal of Statistics 47: 302–314; 2019 © 2019 Statistical Society of Canada     

住宅小区景观的配套设计与绿化

当前，小区的景观配置及绿化已经成为人们选择住宅的重要条件之一。小区景观设计的细节往往是小区景观的配套设计与绿化成功的关键。住宅小区景观的配套设计与绿化是自然与人的完美协调与交融，是人的精神通过加工寄托于景物的一个过程。     

Modifications of sequential designs in bioequivalence trials

Bioequivalence (BE) studies are designed to show that two formulations of one drug are equivalent and they play an important role in drug development. When in a design stage, it is possible that there is a high degree of uncertainty on variability of the formulations and the actual performance of the test versus reference formulation. Therefore, an interim look may be desirable to stop the study if there is no chance of claiming BE at the end (futility), or claim BE if evidence is sufficient (efficacy), or adjust the sample size. Sequential design approaches specially for BE studies have been proposed previously in publications. We applied modification to the existing methods focusing on simplified multiplicity adjustment and futility stopping. We name our method modified sequential design for BE studies (MSDBE). Simulation results demonstrate comparable performance between MSDBE and the original published methods while MSDBE offers more transparency and better applicability. The R package MSDBE is available at https://sites.google.com/site/modsdbe/ . Copyright © 2015 John Wiley & Sons, Ltd.     

三维实体设计与工程制图课程的改革

三维实体设计是工程设计的必然趋势,设计方法的变革导致企业对人才的新需求,也给传统的工程制图课程体系带来了巨大的冲击。改革与现代生产和人才需求不相适应的教学内容,建立以三维设计为主线,以培养创新思维和创新能力为目标的工程制图新体系,是工程制图课程改革的方向。     

基于WEB的远程教学管理软件分析与设计

本论文主要讨论了基于WEB远程教学管理软件的分析与设计。首先对远程教育与传统教育进行了比较研究,确定远程教育是现代教育发展的方向;其次对开发基于WEB远程教学管理软件进行了环境分析和需求分析;最后讨论了远程教学管理软件的实现,包括软件模块结构设计和网站的总体框架。     

论新闻报道策划的实践意义

新闻报道策划 在近几年的新闻实践中应用非常广泛。就报道主题、整合信息、沟通受众和发挥媒体整体优 势等方面论述了新闻报道策划的实践意义。     

工业设计专业数字化设计类课程体系建设的思考

针对数字化技术对工业设计的巨大影响 ,提出了工业设计专业数字化设计类课程体系的框架和对一些课程设置及教学方法的设想     

ALL-BIAS DESIGNS FOR POLYNOMIAL SPLINE REGRESSION MODELS

Polynomial spline regression models of low degree have proved useful in modeling responses from designed experiments in science and engineering when simple polynomial models are inadequate. Where there is uncertainty in the number and location of the knots, or breakpoints, of the spline, then designs that minimize the systematic errors resulting from model misspecification may be appropriate. This paper gives a method for constructing such all‐bias designs for a single variable spline when the distinct knots in the assumed and true models come from some specified set. A class of designs is defined in terms of the inter‐knot intervals and sufficient conditions are obtained for a design within this class to be all‐bias under linear, quadratic and cubic spline models. An example of the construction of all‐bias designs is given.     

"V 什么V"式的句法、语义、语用分析

"V什么V"式是现代汉语中常用的表否定的句式。它形式上最大的特点是"什么"前后的词语相同,它的基本句法结构是主谓结构;"V什么V"式的基本语义特征是表否定,这是通过"什么"实现的;"V什么V"式的语用特点是表示强烈的否定、表达强烈的意志性及简略性。