ORDER STATISTICS FOR TYPE II CENSORED EXPONENTIALLY DISTRIBUTED DATA IN ACCORDENCE OF EXPLANATORY VARIABLES

number: 
1727
English
Degree: 
Author: 
Rasha Abdul Hussein Ali Al Nea'amy
Supervisor: 
Dr. Akram M. Al-Abood
year: 
2007

In this thesis, we consider a regression models for survival censored data of type II in which the underling distributions are exponential or gamma where the effect of the regressor variables on the means is multiplication given by the model  Three methods of estimation for the regression coefficients are considered, namely maximum likelihood (ML), weighted least squares (WLS), and suggest weighted least squares (SWLS). These methods are discussed theoretically and examined practically by Monte Carlo simulation for the case of a single explanatory variable.Moments and higher moments properties of the estimators, such as, bias, variance, skewness, and kurtosis are examined, illustrated and compared.Finally, a new bias reduction estimator to the ML estimator is proposed and shows a higher performance with respect to the other estimators.