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.
Results
Showing 1 to 20 of 24 for “"Zero-inflated Poisson"”.
-
A Simulation Study to Evaluate Bayesian LASSO’s Performance in Zero-Inflated Poisson (ZIP) Models
… count data, it is possible to have excessive zeros in the data in many applications. My thesis concentrates on the variable selection in zero-inflated Poisson (ZIP) models. This thesis work is motivated by Brown et al. (2015), who considered the excessive amount of zero in their data structure …
-
Bayesian approaches to problems in diagnostic testing and underreported count data.
… Finally, the last chapter extends a zero-inflated Poisson distribution accounting for underreporting into the Bayesian paradigm. We analyze this Bayesian model in multiple simulation studies. When underreporting is inaccurately estimated, model parameter estimation can be biased. …
-
Model-based clustering for multivariate time series of counts
… framework for univariate and multivariate zero-inflated time series of counts and applies the models in a clustering scheme to identify groups of count series with similar behavior. The basic modeling framework used is observation-driven Poisson regression with generalized linear model …
-
Evaluating and comparing Gaussian forecasts for discrete process time series.
… similar methods and applications using the Poisson-Lindley integer autoregressive process. In chapter four we extend our work to the zero-inflated Poisson integer autoregressive process. We conclude with a brief summary and discussion in chapter five.
-
Statistical Methods for Genetic Pathway-Based Data Analysis
… model for identifying pathways related to the zero inflated clinical outcomes; the other is to propose a multilevel Gaussian graphical model for exploring both pathway and gene level network structures. For the first problem, we develop a semiparametric model via a Bayesian hierarchical …
-
Zero-Inflated Models to Identify Transcription Factor Binding Sites in ChIP-seq Experiments
… we propose a negative binomial model (NB), a zero-inflated Poisson model (ZIP) and a zero-inflated negative binomial model (ZINB) for peak-calling. Using real ChIP-seq datasets, we show that ZINB model is the best model for ChIP-seq data. Then we incorporate control data, GC count information, …
-
The Doubly Inflated Poisson and Related Regression Models
… 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) and DIP …
-
Estimating Pedestrian Crashes at Urban Signalized Intersections
… vehicle crashes. Regression models such as the Poisson, Zero-inflated Poisson (ZIP), and the Negative Binomial are commonly used to model crashes. Until recently very little research has been conducted on crash prediction modeling for pedestrian-motor vehicle crashes. This thesis considers …
-
An empirical analysis of the effects of fertility on maternal health status in Namibia
… 2013 was used. Firstly the study estimated the Zero-Inflated Poisson (ZIP) model to analyze the effect of socio-economic factors on fertility. Secondly, the Linear Probability Model (LPM) was employed to examine the effect of fertility on maternal health status. To account for possible …
-
Copula-Based Zero-Inflated Count Time Series Models
… finance. In some cases, a specific count, say zero, may occur more often than usual. Additionally, serial dependence might be found among these counts if they are recorded over time. Overlooking the frequent occurrence of zeros and the serial dependence could lead to false inference. In this …
-
Substance Abuse, Marginalization, and Homelessness: Bayesian Perspectives on a Persisting Problem
… transition models of housing state changes and zero inflated Poisson regression models of routine and emergency service counts over two time intervals. Key findings include consistent relationships between living on the streets, alcohol use, and increased marginalization, notably legal problems, …
-
New statistical methods in bioinformatics: for the analysis of quantitative trait loci (QTL), microarrays, and eQTLs
… locus (QTL) when the trait of interest has a zero-inflated Poisson (ZIP) distribution. Though existing methods based on normality may be reasonably applied to some ZIP distributions, the characteristics of other ZIP distributions make such an application inappropriate. We compare our method to …
-
On Development and Performance Evaluation of Some Biosurveillance Methods
… to detect a wide range of shifts in the mean of Poisson distributed biosurveillance data. The application of a sign function on the original GLR chart statistics leads to downward-sided, upward-sided, and two-sided GLR chart statistics in an unified framework. To facilitate the use of such charts …
-
Persistence of Culturable Antibiotic Resistant Fecal Coliforms From Manure Amended Vegetable Fields
… the effects of soil treatment and crop relied on Zero-inflated Poisson Regressions. Antibiotic-resistant culturable fecal coliforms were recoverable from soils across all treatments immediately following application, though persistence throughout the experiment varied by antibiotic. …
-
Parameter Estimation for Normally Distributed Grouped Data and Clustering Single-Cell RNA Sequencing Data via the Expectation-Maximization Algorithm
… takes into account the large proportion of zeros present in the data, which can be either true biological zeros or technological noise. The assumed model for clustering is a mixture of either zero-inflated Poisson or zero-inflated negative binomial distributions, and inference is conducted …
-
Using a multi-dimensional approach to determine the conservation and taxonomic statuses of two rare crayfishes in northern Arkansas
… We ran our fine-scale analysis by modeling zero-inflated Poisson generalized linear models and selecting with AICc. Our best model included proportion of sand in the soil and the presence of a competing burrower as explanatory variables. The interpolated MaxEnt output was found to be a poor …
-
Analysis of Zero-Heavy Data Using a Mixture Model Approach
The problem of high proportion of zeroes has long been an interest in data analysis and modeling, however, there are no unique solutions to this problem. The solution to the individual problem really depends on its particular situation and the design of the experiment. For example, different …
-
A Comparison of the Singing Activity of Carolina Wrens <i>(Thryothorus Ludovicianus)</i>) in Urban and Rural Settings
… chorus lasted nearly twice as long as in July. Zero-inflated Poisson regressions were used to determine the correlations between Carolina Wren singing activity and temperature or anthropogenic noise. Carolina Wren singing activity had significant correlations with both variables.
-
Associated factor of mortality rate amongst patients with AIDS and HIV-TB co-infections using zero inflated negative binomial method
… as count data with a preponderance of zeros. Data in the form of counts and proportions arise in many fields such as studies in medicine, public health, toxicology, epidemiology, sociology, psychology, engineering, agriculture and soon. When the dependent variable is a nonnegative count …
-
Evaluation of soybean cyst nematode (SCN) resistance in perennial glycine species and genome-wide association mapping and genomic prediction study for SCN resistance in common bean and prediction of the short distance movement of soybean rust urediniospores through machine learning
… Shrinkage and Selection Operator (LASSO) method, zero-inflated Poisson/regular Poisson regression model, random forest, and neural network were built and compare to describe deposition of urediniospores collected in passive and active traps. The high prediction accuracy of some of the models …
Page 1 of 2