On Estimation of Variance Components in the Mixed-Effects Models for Longitudinal Data

نویسندگان

  • Mi-Xia Wu
  • Song-Gui Wang
چکیده

For the mixed-effects models with two variance components which is often adopted for analyzing longitudinal data, we establish some necessary and sufficient condition for equality of the analysis of variance estimate and the spectral decomposition estimate of variance components. Thus when this condition is satisfied, both estimates share some statistical properties. Two practical examples satisfying the condition are given.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Estimation of Variance Components for Body Weight of Moghani Sheep Using B-Spline Random Regression Models

The aim of the present study was the estimation of (co) variance components and genetic parameters for body weight of Moghani sheep, using random regression models based on B-Splines functions. The data set included 9165 body weight records from 60 to 360 days of age from 2811 Moghani sheep, collected between 1994 to 2013 from Jafar-Abad Animal Research and Breeding Institute, Ardabil province,...

متن کامل

Estimation of genetic parameters for body weight traits in Baluchi sheep

Genetic parameters for birth weight (BW), weaning weight (WW), 6 months weight (6MW), 9 months weight (9MW) and yearling weight (YW) in Baluchi sheep were estimated using data collected during a 26-year period (1984-2010). Estimates of (co)variance components were obtained by REML procedures by fitting a linear mixed animal model. Significant random effects for each trait were explored by fitti...

متن کامل

Transition Models for Analyzing Longitudinal Data with Bivariate Mixed Ordinal and Nominal Responses

In many longitudinal studies, nominal and ordinal mixed bivariate responses are measured. In these studies, the aim is to investigate the effects of explanatory variables on these time-related responses. A regression analysis for these types of data must allow for the correlation among responses during the time. To analyze such ordinal-nominal responses, using a proposed weighting approach, an ...

متن کامل

Parameter Estimation in Spatial Generalized Linear Mixed Models with Skew Gaussian Random Effects using Laplace Approximation

 Spatial generalized linear mixed models are used commonly for modelling non-Gaussian discrete spatial responses. We present an algorithm for parameter estimation of the models using Laplace approximation of likelihood function. In these models, the spatial correlation structure of data is carried out by random effects or latent variables. In most spatial analysis, it is assumed that rando...

متن کامل

Mixed effects models with censored data with application to HIV RNA levels.

Mixed effects models are often used for estimating fixed effects and variance components in longitudinal studies of continuous data. When the outcome being modelled is a laboratory measurement, however, it may be subject to lower and upper detection limits (i.e., censoring). In this paper, the usual EM estimation procedure for mixed effects models is modified to account for left and/or right ce...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008