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DedicationTo my mom María Antonia for her unconditional love and wisedom. To share with me the passion about knowledge.To my wife Sandra, a great support point over these years.
To my kids, Juan David and Ana María, my best examples of how to learn of the life and don't surrender. i
AcknowledgementsTo me is obvious that this work is a crystallization of countless hints, moments and subtle ideas that many people share with me. So, I would like to thank all of you. A special mention to:• Gilberto A. Paula for the opportunity to work under his guidance, his continuous challenges and his confidence.• Viviana Giampaoli and Eliane Pinheiros because their observations in my qualify exam help me to improve this work.• Luis H. Vanegas his illuminating conversations about classic statistics and semi-parametric models were essentials for this project.• Liliana Blanco C. and Rodrigo de Castro K. for their excellence teaching, full of precision and clarity. These qualities shaped my mind.• Yuri M. Suhov and Anatoli Iambartsev for let me know a little bit about information theory and quantum statistical mechanics.• My fellows, Alejandro Roldán, Kishor K. Ramavarmaraja and Rogério de Assis Medeiros because always had time to discuss mathematical and cultural ideas.• Finally, I would like to thank IME-USP, a great place to learn.ii The central objective of this work is to develop statistical tools for semiparametric regression models with generalized log-gamma errors under the presence of censored and uncensored observations. The estimates of the parameters are obtained through the multivariate version of Newton-Raphson algorithm and an adequate combination of Fisher Scoring and Backffitting algorithms. Through analytical tools and using simulations the properties of the penalized maximum likelihood estimators are studied. Some diagnostic techniques such as quantile and deviance-type residuals as well as local influence measures are derived. The methodologies are implemented in the statistical computational environment R. The package sglg is developed. Finally, we give some applications of the models to real data.Keywords: censored observations, generalized log-gamma distribution, maximum penalized likelihood estimation, natural cubic spline, P-splines, skewness, semi-parametric models.iii O objetivo central do trabalhoé proporcionar ferramentas estatísticas para modelos de regressão semiparamétricos quando os erros seguem distribução loggamma generalizada na presença de observações censuradas ou não censuradas. A estimacão paramétrica e não paramétrica são realizadas através dos procedimentos Newton -Raphson, escore de Fisher e Backfitting (Gauss -Seidel). As propriedades assintóticas dos estimadores de máxima verossimilhança penalizada são estudadas em forma analítica, bem como através de simulações. Alguns procedimentos de diagnóstico são desenvolvidos, tais como resíduos tipo componente do desvio e resíduo quantílico, bem como medidas de influência local sob alguns esquemas usuais de perturbacão. Os principais procediment...