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...

This paper studies a general class of nonlinear varying coefficient time series models with possible nonstationarity in both the regressors and the varying coefficient components. The model accommodates a cointegrating structure and allows for endogeneity with contemporaneous correlation among the regressors, the varying coefficient drivers, and the residuals. This framework allows for a mixtur...

The paper deals with the asymptotic distribution of the least squares estimator of a change point in a regression model where the regression function has two phases — the first linear and the second quadratic. In the case when the linear coefficient after change is non-zero the limit distribution of the change point estimator is normal whereas it is non-normal if the linear coefficient is zero.

to perform stability analysis and study g*e interaction, eight commercial sugar beet varieties were evaluated in eight major sugar beet producing areas of karaj, mashad, miandoab, esfahan, shiraz, kermanshah, moghan and hamadan in three years using a randomized complete block design with four replications. the evaluated varieties were br1, 7233, pp.8, ic, 7233-p29, pp22, h5505 and 41rt. having ...

social capital is a multi-faceted phenomenon in social sciences that massively affects many social fields. it can be a helpful factor in promoting health. among the groups with high burnout, nurses have always shown higher levels of burnout. studies have revealed that social capital can be an important factor affecting burnout. this study aimed to determine the extent of the effect of social ca...