Browsing Teses e dissertações by Title
Now showing items 3-22 of 169
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A abordagem de martingais para o estudo de ocorrência de palavras em ensaios independentes
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 07/04/2017)Let {Xn} be a sequence of i.i.d. random variables taking values in an enumerable alphabet. Given a finite collection of words, we observe this sequence till the moment T at which one of these words appears as a run. In ... -
Uma abordagem estatística para a análise dos resultados das eleições presidenciais
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 15/01/2024)Multiparty data has characteristics that make it compositional data such as a constant sum of components and a limited space known as simplex. Thus, the purpose of the work is to develop a methodology to analyze multi-party ... -
Algoritmos de estimação para modelos Markovianos não-homogêneos
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 27/02/2020)Hidden Markov models are a statistical paradigm which can be used to mode stochastic processeswhere the observable values are directly dependent on a sequence of hidden random variables.In the context of the hidden Markov ... -
Alternative regression models to beta distribution under bayesian approach
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 25/08/2017)The Beta distribution is a bounded domain distribution which has dominated the modeling the distribution of random variable that assume value between 0 and 1. Bounded domain distributions arising in various situations ... -
Análise bayesiana de dados funcionais com o uso de processo Gaussiano e metanálise: uma aplicação para a marcha humana
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 02/05/2019)The term "functional data" arised to accommodate situations in which each observation can be naturally interpreted as a function. These situations have become increasingly common with the availability of measuring instruments ... -
Análise de agrupamentos para dados espectrais
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 11/03/2024)Spectroscopy is the study that uses techniques to measure the spectrum of electromagnetic radiation, including visible light and radiofrequency, where we search for information such as chemical composition, temperature, ... -
Análise de diagnóstico em modelos de regressão ZAGA e ZAIG
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 10/03/2016)Residuals play an important role in checking model adequacy and in the identi cation of outliers and in uential observations. In this paper, we studied two class of residuals for the zero adjusted gamma regression model ... -
Análise de textos por meio de processos estocásticos na representação word2vec
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 03/03/2021)Within the field of Natural Language Processing (NLP), the word2vec model has been extensively explored in the field of vector representation of words. It is a neural network that is based on the hypothesis that similar ... -
Análise teórica e computacional de processos estocásticos inspirados em sistemas biológicos.
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 06/01/2020)The aim of this work is to present two methodologies based on the theoretical and computational analysis of continuous time stochastic processes inspired by biological systems, whose dynamics are influenced by the stochastic ... -
Análises Bayesiana para o modelo de regressão Birnbaum-Saunders com zeros ajustados
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 11/08/2021)Modeling based on the Birnbaum-Saunders distribution has received considerable attention in recent years. In this work we consider the reparametrized Birnbaum-Saunders distribution with zero-adjusted (ZARBS) (SANTOS-NETO ... -
Uma aproximação do tipo Euler-Maruyama para o processo de Cox-Ingersoll-Ross
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, , 26/02/2015)In this master's thesis we work with Cox-Ingersoll-Ross (CIR) process. This process was originally proposed by John C. Cox, Jonathan E. Ingersoll Jr. and Stephen A. Ross in 1985. Nowadays, this process is widely used in ... -
Avaliação da proficiência em inglês acadêmico através de um teste adaptativo informatizado
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 09/04/2015)This work describes the steps for converting a linear paper-and-pencil English proficiency test for academic purposes, composed with multiple choice items that are administered following the admissible probability ... -
Avaliação do lasso e métodos alternativos em modelos de regressão logística
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 11/03/2021)Logistic regression has always been an important tool not only in the area of statistics, but also in several other areas such as economic, biological and medical. In many of these areas it is common to encounter problems ... -
Bandas de predição usando densidade condicional estimada e um modelo LDA com covariáveis
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 15/10/2021)Machine learning methods are divided into two main groups: supervised and unsupervised methods. In the first part of this work, we develop a method for creating prediction bands that can be applied to supervised problems. ... -
Bayesian and classical inference for the generalized gamma distribution and related models
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 22/02/2018)The generalized gamma (GG) distribution is an important model that has proven to be very flexible in practice for modeling data from several areas. This model has important sub-models, such as the Weibull, gamma, lognormal, ... -
Bayesian estimation of dynamic mixture models by wavelets
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 20/04/2023)Gaussian mixture models are used successfully in various statistical learning applications. The good results provided by these models encourage several generalizations of them. Among possible adaptations, one can assume a ... -
Bayesian inference for term structure models
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 09/06/2022)We explore recent advances in Bayesian methods in order to estimate the Vasicek, CIR and dynamic Nelson-Siegel (DNS) models for term structure of interest rates. The models are specified as state space time series. The ... -
A bayesian nonparametric approach for the two-sample problem
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 19/11/2018)In this work, we discuss the so-called two-sample problem (PEARSON; NEYMAN, 1930) assuming a nonparametric Bayesian approach. Considering X 1 ,...,X n and Y 1 ,...,Y m two inde- pendent i.i.d samples generated from P 1 ... -
Bayesian spatial process models for activation patterns in transcranial magnetic stimulation mapping
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 07/07/2023)In recent years, Spatial statistical models have been gaining rapid attention for solving problems in biological systems due to the improvement in spatial data collection. It has proven extremely important in unveiling ... -
Bayesian variable selection for logistic mixture models with Pólya-Gamma data augmentation
(Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 15/02/2022)In this work, Bayesian methods for estimating and selecting variables in a mixture of logistic regressions model are presented. In order to simplify its Bayesian estimation, we extend the data augmentation approach ...