The regular maximum partial likelihood estimator is biased when the covariates in the Cox proportional hazards model are measured with error, unless the measurement errors tend to zero. Although several alternative estimators have been proposed, theoretical justifications for them are lacking. We try to fill this gap by showing that the corrected maximum partial likelihood estimator proposed by...

Abstract: In this paper, we give an explanation to the failure of two likelihood ratio procedures for testing about covariance matrices from Gaussian populations when the dimension is large compared to the sample size. Next, using recent central limit theorems for linear spectral statistics of sample covariance matrices and of random F-matrices, we propose necessary corrections for these LR tes...

INTERVAL ESTIMATION OF EXCESS RISK RELATED EFFECTIVE DOSES IN TOBIT MODELS by Jia Wang ADVISOR: Professor Nan Lin December 2009 Saint Louis, Missouri In this thesis we consider interval estimation of excess risk related effective dose (ERED) in dose-response studies using tobit model. Let P (x) be the probability of response at dose level x. Considering the background probability P (0), excess ...

land use maps are the most essential information in the hand of natural resources managers.in the present research, to prepare dahat abbas land use map, landsat etm+ (1386) data was used. the image was geometrically corrected with root mean square error of less than 0.47. for classification, artificial neural network, support vector machine and maximum likelihood methods were used.finally, thel...

A randomised controlled trial was conducted to evaluate the effect of a motor developmental program in improving motor performance in Thai infants born preterm. Eighty-four preterm born infants were randomly assigned to either a control or intervention group. Additionally, 27 low-risk preterm infants were included forming a comparative group for this study. From term equivalent age to four mont...

This report discusses the calculation of analytic second-order bias techniques for the maximum likelihood estimates (for short, MLEs) of the unknown parameters of the distribution in quality and reliability analysis. It is well-known that the MLEs are widely used to estimate the unknown parameters of the probability distributions due to their various desirable properties; for example, the MLEs ...

Consider the case where the exact values of covariates in the proportional hazards model may not be observed but instead, only surrogates for them involving measurement errors are available. The maximum likelihood estimate based on the partial likelihood with the true covariate replaced by the observed surrogate is even asymptotically biased and may cause seriously misleading results in covaria...

In this paper, we present case deletion and mean shift outlier models for linear mixed measurement error models using the corrected likelihood of Nakamura (1990). We derive the corrected score test statistic for outliers detection based on mean shift outlier models. Furthermore, several case deletion diagnostics are constructed as a tool for influence diagnostics. It is found that they can be w...

Pfanzagl and Wefelmeyer (1978) show that bias corrected ML estimators are higher order efficient. Their procedure however is computationally complicated because it requires integrating complicated functions over the distribution of the MLE estimator. The purpose of this paper is to show that these integrals can be replaced by sample averages without affecting the higher-order variance. We focus...