Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"excess zeros"”.
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Multivariate Analysis of Dietary Data in the Presence of Excess Zeros and Measurement Error
… are required to deal with measurement error, excess zeros in the intake distributions, and correlated preferences for frequency of consumption and portion sizes across foods. The thesis demonstrates the use of contemporary statistical methods, based on mixed-distributions and mixed-effects …
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New Multivariate Zero-Inflated Beta-Binomial Distribution
… multivariate proportional data with extra zeros. Comparing with the binomial model, the beta-binomial model is a better alternative for explicitly accounting for over-dispersion, and zero-inflated model has a better performance on analyzing the data with excess zeros. For dealing with the …
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Bayesian methods for hurdle models.
… to zero-inflated models for count data with excess zeros. They consist of two parts: a binary model indicating a positive response (the "hurdle") and a zero-truncated count model. One or both parts of the model can depend on covariates, which may or may not coincide. In this dissertation, we …
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The Doubly Inflated Poisson and Related Regression Models
… of distributions. For data consisting of only excess zeros, in a seminal paper Lambert (1992) introduced Zero-Inflated Poisson (ZIP) model, which is a mixture model that accounts for the inflated zeros. In this thesis, two Doubly Inflated Poisson (DIP) probability models, DIP (<em>p</em>, λ) …
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Variable Selection and Hypothesis Testing for High-Dimensional Models in Mental Health Research
… hierarchical structures, and outcomes exhibiting excess zeros. These characteristics pose significant challenges for variable selection, model estimation, hypothesis testing, and sample size determination, often undermining statistical stability, interpretability, and computational efficiency. …
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Bayesian modelling of mixed outcome types using random effect.
… in a binary covariate (MisPSN model), and excess zeros in the Poisson counts (ZipPSN model). Simulation studies are performed for these models, and the results show that ignoring these complications result in estimated regression coefficients further from the truth when compared to the …
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An Economic Analysis of Secure Messaging between Patients and Providers
… estimating count and continuous models with an excess number of zeros and unobserved individual heterogeneity. This approach is similar to a zero inflated model in the way it deals with excess zeros, but unlike a zero inflated model it is robust to distributional misspecifications. Also, its …
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Component-wise Z-residual Diagnosis for Bayesian Hurdle Models
… research areas, count data often exhibit more zeros than expected under standard distributions like the Poisson or negative binomial. These “excess zeros” are common in fields such as health economics, criminology, and ecology, and can distort inference if not properly accounted for. …