reference curves are useful tools to monitor children’s growth status and can promote growth velocity in infants. in this regard, various parametric and semi-parametric methods are frequently used in the last decades. in the present paper, nonparametric quintile regression method is used as a powerful and applicable methodology to estimate height curves and normal values of height-for-age in ch...

The issue of poverty traps is assessed using quantile regression. For that an augmentation of the usual convergence regressions by quadratic and cubic terms is used with emphasis on curve fitting rather than parameter estimation. The results show that the generic mechanism leading to poverty traps predominantly applies to countries with relatively low levels of income per capita or per worker t...

this paper deals with ridge estimation of fuzzy nonparametric regression models using triangular fuzzy numbers. this estimation method is obtained by implementing ridge regression learning algorithm in the la- grangian dual space. the distance measure for fuzzy numbers that suggested by diamond is used and the local linear smoothing technique with the cross- validation procedure for selecting t...