Bayesian model pooling for the analysis of generalized linear models with missing-not-at-random covariates

Download
2020-9
Çiftçi, Sezgin
Missing data in modeling is one of the main problems of researchers. If the missingness mechanism is related to the value of the variable itself, then the missing is defined as not-at-random (MNAR). Additionally, finding the best model in statistics has always been the focus of researchers. However, it's known from examples that there may be any other model with the same best fit but has different estimated coefficients. Hence, an uncertainty about model selection that may be problematic in estimation especially when there is also uncertainty about the accuracy of the estimations caused by MNAR mechanism can cause misleading inferences. In this thesis, a hybrid Bayesian method is developed for the analysis of a generalized linear model (GLM) with MNAR covariates. In the analysis of GLM with MNAR covariates, main response and missingness probabilities of the MNAR covariates are modeled jointly. In our approach, we create a model space as a set of the best fits among all possible joint models. This is accomplished by the Reversible Jump Monte Carlo Markov Chain (RJMCMC) approach that is adopted here. Coefficient estimates are obtained by pooling the posterior estimations of each model with the posterior model probabilities, which are also calculated within RJMCMC algorithm.

Suggestions

Bayesian semiparametric models for nonignorable missing datamechanisms in logistic regression
Öztürk, Olcay; Kalaylıoğlu Akyıldız, Zeynep Işıl; Department of Statistics (2011)
In this thesis, Bayesian semiparametric models for the missing data mechanisms of nonignorably missing covariates in logistic regression are developed. In the missing data literature, fully parametric approach is used to model the nonignorable missing data mechanisms. In that approach, a probit or a logit link of the conditional probability of the covariate being missing is modeled as a linear combination of all variables including the missing covariate itself. However, nonignorably missing covariates may n...
Comparison of physical and numerical dam-break simulations
Bozkuş, Zafer (Turkiye Bilimsel ve Teknik Arastirma Kurumu, 1998-01-01)
Laboratory data obtained from model studies of an existing dam under three different failure scenarios are presented. Moreover, the numerical failure simulations of the same dam were performed by employing two state-of-the-art numerical models, namely, SMPDBK and DAMBRK, both developed at the National Weather Service (NWS) in the United States. Comparison of the measured and computed results indicate that both numerical models predict peak flood elevation with somewhat reasonable accuracy. However, the resu...
Bayesian solutions and performance analysis in bioelectric inverse problems
Serinağaoğlu Doğrusöz, Yeşim; MacLeod, RS (Institute of Electrical and Electronics Engineers (IEEE), 2005-06-01)
In bioelectric inverse problems, one seeks to recover bioelectric sources from remote measurements using a mathematical model that relates the sources to the measurements. Due to attenuation and spatial smoothing in the medium between the sources and the measurements, bioelectric inverse problems are generally ill-posed. Bayesian methodology has received increasing attention recently to combat this ill-posedness, since it offers a general formulation of regularization constraints and additionally provides s...
AI-based predictive modeling for safety assessment in construction industry
Ayhan, Bilal Umut; Tokdemir, Onur Behzat; Department of Civil Engineering (2019)
The predictive modeling is a popular research area among the researchers. Most of the proposed models cannot provide a solution for the needs of every contractor as the existing ones served for only a specific task. Therefore, using these systems become inevitably burden on contractors due to its difficulty of use. The thesis aims to provide an AI-based safety assessment strategy for every project. The assessment strategy encapsulated the detection of trends in safety failures and corrective actions to prev...
Neural network models as a management tool in lakes
Karul, C; Soyupak, S; Yurteri, C (Springer Science and Business Media LLC, 1999-01-01)
A research was made on the potential use of neural network based models in eutrophication modelling. As a result, an algorithm was developed to handle the practical aspects of designing, implementing and assessing the results of a neural network based model as a lake management tool. To illustrate the advantages and limitations of the neural network model, a case study was carried out to estimate the chlorophyll-a concentration in Keban Dam Reservoir as a function of sampled water quality parameters (PO4 ph...
Citation Formats
S. Çiftçi, “Bayesian model pooling for the analysis of generalized linear models with missing-not-at-random covariates,” Ph.D. - Doctoral Program, Middle East Technical University, 2020.