SUMMARY The object of the present investigation is to consider a robust procedure for the problem of providing a bounded-length confidence interval for the regression coefficient (in a simple regression model) based on Kendall's (1955) tau. The problem of estimating the difference in the location parameters in the two-sample case may be viewed as a special case of our problem. It is shown that ...

Let Y be a binary random variable and X a scalar. Let β̂ be the maximum likelihood estimate of the slope in a logistic regression of Y on X with intercept. Further let x̄0 and x̄1 be the average of sample x values for cases with y = 0 and y = 1, respectively. Then under a condition that rules out separable predictors, we show that sign(β̂) = sign(x̄1− x̄0). More generally, if xi are vector valued the...

The complexity of semiparametric models poses new challenges to statistical inference and model selection that frequently arise from real applications. In this work, we propose new estimation and variable selection procedures for the semiparametric varying-coefficient partially linear model. We first study quantile regression estimates for the nonparametric varying-coefficient functions and the...

The complexity of semiparametric models poses new challenges to statistical inference and model selection that frequently arise from real applications. In this work, we propose new estimation and variable selection procedures for the semiparametric varying-coefficient partially linear model. We first study quantile regression estimates for the nonparametric varying-coefficient functions and the...

OBJECTIVES This research's main goals were to build a predictor for a turnaround time (TAT) indicator for estimating its values and use a numerical clustering technique for finding possible causes of undesirable TAT values. MATERIALS AND METHODS The following stages were used: domain understanding, data characterisation and sample reduction and insight characterisation. Building the TAT indic...

To study the relationship between chlorophyll-a and environmental variables during spring algal bloom in Xiangxi Bay of Three Gorges Reservoir, the support vector regression (SVR) model was established. In surveys, 11 stations have been investigated and 264 samples were collected weekly from March 4 to May 13 in 2007 and February 16 to May 10 in 2008. The parameters in SVR model were optimized ...

seasonal activity and spatial distribution of eoteranychus frosti mcgregor, tydeus longisetosus (elbagouy and momen) and zetzellia mali ewing were studied during 9th july to 22th october 2006 in an unsprayed apple orchard, maragheh region, northwest of iran. also the density dependence interaction between preys and predator was assessed. to estimate the spatial distribution pattern of these spe...

in this study, the number of 1802 longevity records of ewes collected during 1989 to 2010 in breeding station of lori-bakhtiari sheep flocks were used to estimate of genetic, environmental and phenotypic trends for economic lifetime. the breeding values of a ewe’s lifetime were estimated by restricted maximum likelihood procedure under an animal model of univariate analysis. the best linear unb...

Varying-coefficient linear models arise from multivariate nonparametric regression, nonlinear time series modelling and forecasting, functional data analysis, longitudinal data analysis, and others. It has been a common practice to assume that the vary-coefficients are functions of a given variable which is often called an index. A frequently asked question is which variable should be used as t...