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Métodos Bayesianos para seleção de modelos de mistura de distribuições normais e t de Student assimétricas
(Universidade Federal de São Carlos, 2023-06-28)
In this work, we consider mixture models whose components of the mixture are modeled by the skew normal and skew t distributions. For the estimation of these skew mixtures models, we used a Bayesian approach, via Markov ...
Modelos de fração de cura com fragilidade inflacionado de zero sob diferentes esquemas de ativação
(Universidade Federal de São Carlos, 2023-08-22)
In this doctoral thesis, the proposed methodology is based on zero-inflated survival data to deal with situations where there is a fraction of inflated (or adjusted) zeros and cured cases considering different activation ...
Using VAE for incomplete educational data
(Universidade Federal de São Carlos, 23-03-13)
In Psychometrics, especially in educational assessments, incomplete databases are common.
An individual may leave items unanswered in an assessment due to lack of time, forgetting
the content involved, nervousness, or ...
Teoremas limite para variáveis aleatórias de Bernoulli dependentes
(Universidade Federal de São Carlos, 2023-03-22)
In this work, we consider a sequence of correlated Bernoulli variables whose probability of success for the current trial depends conditionally on previous trials. This conditional probability is given as a linear function ...
Seleção de covariância para o modelo grafo gaussiano via reversible jump
(Universidade Federal de São Carlos, 2023-02-24)
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 ...
Reliability analysis of repairable systems considering unobserved heterogeneity and competing risks
(Universidade Federal de São Carlos, 2023-10-09)
In repairable systems, the failure process defined by the failure intensity function can be impacted by three crucial characteristics: the type of repair performed after the failures occur, the underlying cause of the ...
Modelos alternativos para classificação em dados desbalanceados
(Universidade Federal de São Carlos, 2023-08-11)
In binary classification, the most used method is logistic regression model. However, several authors indicate that this model is not suitable when the data are imbalanced; for this, different asymmetric link functions as ...
Uma abordagem bayesiana para avaliação de concordância entre dispositivos de medição de uma variável funcional
(Universidade Federal de São Carlos, 2023-09-15)
It is common in the industrial and clinical context to seek more precision, accurate, accessible and cheaper equipments. Therefore, it is important for these fields to have a way to compare the agreement of new devices ...
Modelo de regressão chances de sobrevivência proporcionais para dados discretos com presença de censura
(Universidade Federal de São Carlos, 2023-04-25)
Survival models, in their majority, consider continuous survival times. However, in several studies these times are discrete, and in some occasions, it is not advisable to use a continuous model to analyze discrete data. ...
Modelos de sobrevivência bivariados induzidos por fragilidade
(Universidade Federal de São Carlos, 2022-07-18)
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 ...