Teses e dissertações: Envíos recientes

Mostrando ítems 21-40 de 158

    • Inferência Bayesiana para modelos de volatilidade estocástica baseados em mistura de escala da distribuição normal assimétrica 

      Condori, Ritha Rubi Huaysara (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 28/02/2023)
      This dissertation aims to evaluate and compare the performance of the No-U-Turn Sampler (NUTS) algorithm, implemented in the Stan software, in estimating the parameters of stochastic volatility models with leverage based ...

    • Seleção de covariância para o modelo grafo gaussiano via reversible jump 

      Santos, Eriton Barros dos (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 24/02/2023)
      The purpose of the Graphical Gaussian model is to find the covariance structure that represents the relationship between random variables, whose joint distribution is a multivariate normal. This is a tool used to modeling ...

    • Scalable and interpretable kernel methods based on random Fourier features 

      Otto, Mateus Piovezan (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 29/03/2023)
      Kernel methods are a class of statistical machine learning models based on positive semidefinite kernels, which serve as a measure of similarity between data features. Examples of kernel methods include kernel ridge ...

    • Estimação do número de comunidades no modelo estocástico de blocos com correção de grau 

      Tapia, Cristel Ecaterin Vera (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 14/12/2022)
      The stochastic block model (SBM) is a random graph model that splits the set of vertices into blocks, and the probability connection between each pair of vertices depends on the blocks to which the vertices belong. The ...

    • Nova classe de modelos paramétricos para análise de sistemas reparáveis 

      Lopes, Tito Lívio da Cunha (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 13/01/2023)
      The Arithimetic Reduction of Age (ARA) model class from Doyen e Gaudoin (2004) has been widely used in the analysis of repairable systems, whose repair effect is expressed by an arithmetic age reduction. However, the ...

    • Extensões do resíduo quantílico 

      Andrade, Ana Carolina do Couto (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 20/12/2022)
      Regression models have profound importance in analyses that aim to investigate the relationship between a dependent variable and a set of predictor variables. The diagnostic analysis is a fundamental step in validating a ...

    • Modelos de sobrevivência induzidos por fragilidade discreta com fração de cura e riscos proporcionais 

      Espírito Santo, Ana Paula Jorge do (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 21/10/2022)
      This work presents two new survival models induced by discrete frailty with unobserved heterogeneity and proportional hazards structure, for lifetime data. The first model consider the discrete frailty variable with Katz ...

    • Um estudo dos modelos de sobrevivência de longa duração LIGcr e GEPGWcr 

      Stella, Caroline Amantea (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 04/10/2022)
      In this work we study two long-term survival models denomined Logaritmic Inverse Gaussian cure rate (LIGcr) model and Geometric Exponentiated Power Generalized Weibull cure rate (GEPGWcr) model. Both models take into ...

    • Métodos de estimação baseados em modelos na presença de dados faltantes 

      Ribeiro, Taís Roberta (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 14/10/2022)
      The missing data are observations that should have been made, but were not for some reason, thus reducing the ability to understand the nature of the phenomenon, in addition to making it difficult to extract information ...

    • Observações atípicas em alta dimensão 

      Hisatugu, Matheus Toshio (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 15/09/2022)
      Outliers and heteroskedastic noise are two common situations in Statistics. Nowadays the amount of generated data is very high and for this reason it is possible to find high dimensional data (the dimension d is just as ...

    • A nonparametric bayesian approach for modeling and comparison of functional data 

      Moreira, Diogo Barboza (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 02/09/2022)
      The current advances of technology provides, among other things, several ways of collecting data, which enlarges the possibility of studying new phenomena. Researches focused on studying the functional relation between ...

    • Modelos de sobrevivência bivariados induzidos por fragilidade 

      Bedia, Elizbeth Chipa (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 18/07/2022)
      Frailty models have been developed to quantify both heterogeneity as well as association in multivariate time-to-event data. The frailty distributions used in many studies include the gamma, inverse Gaussian (IG) or stable ...

    • Bayesian inference for term structure models 

      Martins, Thomas Correa e Silva (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 ...

    • Modeling survival data based on a reparameterized weighted Lindley distribution 

      Mota, Alex Leal (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 24/06/2022)
      In this work, we propose different statistical modeling for survival data based on a reparameterized weighted Lindley distribution. Initially, we present this distribution and study its mathematical properties, maximum ...

    • Equações diferenciais estocásticas e as estratégias de hedging no mercado de opções 

      Souza, Matheus de Oliveira (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 24/06/2022)
      The Stochastic Differential Equation models (SDEs) assume an important role in finances. The major part of these models try to help the investors with the risk management of the financial activities and they use SDEs for ...

    • Nonparametric pragmatic hypothesis testing 

      Lassance, Rodrigo Ferrari Lucas (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 13/06/2022)
      In statistical testing, a pragmatic hypothesis is an extension of a precise one, taking cases on the vicinity of the null as being equally worthy of appraisal. Unlike standard procedures, pragmatic hypotheses allow the ...

    • Redes neurais para grafos e suas aplicações aos sistemas complexos 

      Carvalho, Guilherme Michel Lima de (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 08/04/2022)
      Complex systems are composed of several components that interact with each other. A natural approach for these types of systems is to use mathematical graph abstraction. In different contexts in the real world, it is ...

    • Testes bayesianos em ensaios clínicos 

      Silva, Josimara Tatiane da (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 22/02/2022)
      In this thesis, we propose two new Bayesian approaches for equivalence hypotheses testing for proportions and prove that these Bayesian hypotheses tests are equivalent. These Bayesian methodologies applied to equivalence ...

    • Poincaré recurrence times in stochastic mixing processes 

      Amorim, Vitor Gustavo de (Universidade Federal de São Carlos, UFSCar, Programa Interinstitucional de Pós-Graduação em Estatística - PIPGEs, Câmpus São Carlos, 17/02/2022)
      In the context of the discrete-time stochastic processes, this thesis presents new results on Poincaré recurrence theory. After a complete review of recent results, we present a new theorem on the exponential approximations ...

    • Bayesian variable selection for logistic mixture models with Pólya-Gamma data augmentation 

      Bogoni, Mariella Ananias (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 ...