A measure of the predictive capability of a proportional hazards regression is derived. The measure is based on the residuals appropriate to proportional hazards regression. A population version is presented and can be seen not to depend on the censoring mechanism under the provision that any such censoring be independent or conditionally independent of the failure mechanism given the covariate...

Recently, a new entropy based divergence measure has been introduced which is much like Kullback-Leibler divergence. This entropy measures the distance between an empirical and a prescribed survival function and is a lot easier to compute in continuous distributions than the K-L divergence. In this paper we show that this distance converges to zero with increasing sample size and we apply it to...

We propose a new family of distributions referred to as Weibull taildistributions. This family is designed to model left tails with exponential behavior. The exponent can be estimated using inference procedures adapted from the Weibull tail-distributions literature. Let us define a negative Weibull tail-distribution through its distribution function by: F (x) = exp {

BACKGROUND The use of three-dimensional (3D) surface imaging is becoming more popular and accepted in the fields of Medicine and Dentistry. The present study aims to develop a technique to automatically localise and quantify soft-tissue asymmetry in adults using 3D facial scans. This may be applied as a diagnostic tool to monitor growth and dynamic changes and to evaluate treatment outcomes. ...

This paper considers various estimation methods to estimate the unknown parameters of DUS Inverse Weibull (DIW) distribution using maximum likelihood (ML), least squares (LS), weighted (WLS), Cramer-von Mises (CVM) and Anderson-Darling (AD) estimators. A Monte-Carlo simulation study is conducted determine most preferable estimators in terms their efficiencies. Furthermore, error simple linear r...

OBJECTIVES This study evaluated and compared Weibull parameters of resin bond strength values using six different general-purpose statistical software packages for two-parameter Weibull distribution. METHODS Two-hundred human teeth were randomly divided into 4 groups (n=50), prepared and bonded on dentin according to the manufacturers' instructions using the following resin cements: (i) Vario...

In many situations individuals with the same values for all observed covariables will have important covariables which cannot be measured or which were not measured during the study. These unknown or unmeasured covariables make the subpopulations, as defined by the observable covariables, heterogeneous. The present study explores the affect of unobservable heterogeneity in the context of Weibul...