3 Illustrative examples 4 3.1 Linear regression model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.1 Log transformation in the response . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.2 Log transformation in the explanatory variable . . . . . . . . . . . . . . . . . . . . 9 3.1.3 Log transformation in both the response and the explanatory variable ...

This paper reviews several common challenges encountered in statistical analyses of epidemiological data for epidemiologists. We focus on the application of linear regression, multivariate logistic regression, and log-linear modeling to epidemiological data. Specific topics include: (a) deletion of outliers, (b) heteroscedasticity in linear regression, (c) limitations of principal component ana...

Precise estimation of root biomass is important for understanding carbon stocks and dynamics in forests. Traditionally, biomass estimates are based on allometric scaling relationships between stem diameter and coarse root biomass calculated using linear regression (LR) on log-transformed data. Recently, it has been suggested that nonlinear regression (NLR) is a preferable fitting method for sca...

SUMMARY This paper discusses the log-linear model for multi-way contingency table , where the cell values represent the frequency counts that follow an extended negative multinomial distribution. This is an extension of negative multinomial log-linear model described by Evans (1989). The parameters of the new model are estimated by maximum likelihood method. The likelihood ratio test for the ge...

aim : to determine the associated factors of reflux duration, using quantile regression model. background : reflux is one of the most prevalent gastrointestinal disorders.  statistical tools are widely used to assess the associated factors on reflux severity and frequency. patients and methods : a door to door questionnaire has been used to evaluate gastrointestinal symptoms including reflux an...

Reservoir permeability is a critical parameter for characterization of the hydrocarbon reservoirs. In fact, determination of permeability is a crucial task in reserve estimation, production and development. Traditional methods for permeability prediction are well log and core data analysis which are very expensive and time-consuming. Well log data is an alternative approach for prediction of pe...