Digital Module 16: Longitudinal Data Analysis     

Jeffrey R. Harring  Tessa L. Johnson 《Educational Measurement》2020,39(3):137-138

In this digital ITEMS module, Dr. Jeffrey Harring and Ms. Tessa Johnson introduce the linear mixed effects (LME) model as a flexible general framework for simultaneously modeling continuous repeated measures data with a scientifically defensible function that adequately summarizes both individual change as well as the average response. The module begins with a nontechnical overview of longitudinal data analyses drawing distinctions with cross-sectional analyses in terms of research questions to be addressed. Nuances of longitudinal designs, timing of measurements, and the real possibility of missing data are then discussed. The three interconnected components of the LME model—(1) a model for individual and mean response profiles, (2) a model to characterize the covariation among the time-specific residuals, and (3) a set of models that summarize the extent that individual coefficients vary—are discussed in the context of the set of activities comprising an analysis. Finally, they demonstrate how to estimate the linear mixed effects model within an open-source environment (R). The digital module contains sample R code, diagnostic quiz questions, hands-on activities in R, curated resources, and a glossary.  相似文献   

关于我国离婚法定条件的探讨——混合标准还是单一标准     

邓娟 《安徽职业技术学院学报》2005,4(3):29-33

关于离婚法定条件的探讨贯穿于我国婚姻法发展的整个过程。从1950年新中国第一部婚姻法到1980年婚姻法的重新制定,乃至2001年婚姻法的修订,都是一个探索的过程,但探索的结论并没有很大的突破,仍是将离婚法定条件定为感情或婚姻破裂的单一标准。出于完善我国婚姻立法中的法理基础的需要,笔者以为应在我国婚姻立法中确立混合标准的离婚法定条件。  相似文献   

广义冠状系统中有关共轭圈的一个注记     

柯小玲 《闽江学院学报》2007,28(2):31-33

克库勒结构和共轭圈对于苯环系统或冠状系统的分类及其结构特征的刻画起着重要作用,因此有关共轭圈的研究及其结果在诸多文献中出现.文章就广义冠状系统给出其有关共轭圈的下列结果：一个至多含有两条悬挂边且含有克库勒结构M的广义冠状系统必有一个M-共轭圈等.  相似文献   

论社会主义初级阶段的混合所有制经济     

王艳 《信阳师范学院学报(哲学社会科学版)》2004,24(4):41-43

根据党的十五大以来有关社会主义初级阶段基本经济制度的重要阐述,我国应从所有制结构、分配制度和经济运行机制等三个方面做进一步的调整、变革和创新。  相似文献   

基于OBE理念的二外日语混合式教学改革与实践     

闪晓宇 《保定学院学报》2022,(1)

为了培养具有创新思维和能力的复合型外语类高素质应用型人才,基于OBE理念采用混合式教学模式,提出课堂、作业、考核等方面的改革措施,对英语专业二外日语教学进行改革,取得了较好的教学效果,实现了教学效果和学生学习积极性的同步提高。  相似文献   

Incremental training intensities increases loads on the lower back of elite female rowers     

Erica M. Buckeridge  Anthony M.J. Bull  Alison H. McGregor 《Journal of sports sciences》2016,34(4):369-378

Lumbar-pelvic kinematics change in response to increasing rowing stroke rates, but little is known about the effect of incremental stroke rates on changes in joint kinetics and their implications for injury. The purpose of this study was to quantify the effects of incremental rowing intensities on lower limb and lumbar-pelvic kinetics. Twelve female rowers performed an incremental test on a rowing ergometer. Kinematic data of rowers’ ankle, knee, hip and lumbar-pelvic joints, as well as external forces at the handle, seat and foot-stretchers of the rowing machine were recorded. Inter-segmental moments and forces were calculated using inverse dynamics and were compared across stroke rates using repeated measures ANOVA. Rowers exhibited increases in peak ankle and L5/S1 extensor moments, reductions in peak knee moments and no change in peak hip moments, with respect to stroke rate. Large shear and compressive forces were seen at L5/S1 and increased with stroke rate (P < 0.05). This coincided with increased levels of lumbar-pelvic flexion. High levels of lumbar-pelvic loading at higher stroke rates have implications with respect to injury and indicated that technique was declining, leading to increased lumbar-pelvic flexion. Such changes are not advantageous to performance and can potentially increase the risk of developing injuries.  相似文献   

2015喀山游泳世锦赛混合双人跳水比赛制胜因素分析     

韩风歌 《湖北体育科技》2016,(9):813-818

以2015喀山游泳世锦赛混合双人跳水的比赛视频和成绩为研究对象,综合运用数理统计、录像观察、文献资料等研究方法。研究认为,混合双人跳水比赛除较量运动员的动作完成质量之外,动作的同步性对比赛结果有着极为重要影响,此外动作组别、动作姿势、转体周数及翻腾周数的选择也是影响比赛制胜的因素。  相似文献   

广义马氏过程及其熵率     

张景晓  连秀国  李光芹  姜曰华 《临沂师范学院学报》2004,26(3):26-28

讨论了k步广义马氏过程及其时间不变性和平稳性，给出了熵率的两种定义，说明了其等价性，还给出了平稳的广义马氏链熵率的计算公式．  相似文献   

Fibonacci数列与对角形行列式   总被引：1，自引：0，他引：1  

杨长恩 《咸阳师范学院学报》2007,22(4):3-5,11

通过对Fibonacci数列与对角形行列式的研究,得到了它们之间的密切关系。  相似文献   

广义线性系统极点配置的方法     

杨战民  刘利华  谭宏武  王社宽 《咸阳师范学院学报》2004,19(2):5-7

研究了广义线性系统的极点配置问题，利用矩阵的奇异值分解和矩阵的广义逆得到了广义线性系统的奇异值标准形，使得广义线性系统的极点配置问题转变为正常系统的极点配置问题，从而给出广义线性统极点配置的一种新方法。  相似文献