This thesis addresses three major issues in data mining regarding feature subset selection in large dimensionality domains, plausible reconstruction of incomplete data in cross-sectional applications, and forecasting univariate time series. For the automated selection of an optimal subset of...

In much of applied statistics variables of interest are measured with error. In particular, regression with covariates that are subject to measurement error requires adjustment to avoid biased estimates and invalid inference. We consider two aspects of this problem. Detection Limits (DL) arise...

This dissertation focuses on two topics in semiparametric statistical methods and their applications in medical science: (1) prediction of patients? lifetimes based on their risk profiles; (2) estimation of dynamic exposure effects on survival outcomes. In Chapter II, we develop multiple...

In the first part of the dissertation, we derive two methods for responders analysis in longitudinal data with random missing data. Often a binary variable is generated by dichotomizing an underlying continuous variable measured at a specific point in time according to a prespecified threshold...

In many clinical studies, researchers are mainly interested in studying the effects of some prognostic factors on the hazard of failure from a specific cause while individuals may failure from multiple causes. This leads to a competing risks problem. Often, due to various reasons such as finite...

Material resources affect the levels of mortality. In cross-sectional relationships income has been found to be positively associated with survival, both within and between countries. Preston (1975, 1976), in particular, using cross-national data for three separate decades of the 20th century,...

At the moment variety of methods and commercial tools are available that can be used to model business systems and implement data integrity constraints through the functionality of active database management systems. Unfortunately, these tools do not support data validation – the...

Dėl įvairių priežasčių duomenų bazėse saugomi duomenys genda, todėl vien riboti įvesti klaidingus duomenis nepakanka. Duomenų kokybė užtikrinama draudžiant įvesti klaidingus duomenis ir tikrinant bei valant duomenų bazėse saugomus duomenis. Klaidingų duomenų įvedimo ribojimai...

Current GIS are often described as rich in functionality but poor in knowledge content and transfer. This paper presents a prototype for communicating data quality in spatial databases using a hybrid design between data-driven and user-driven factors based upon traditional communication and...