Conditional Survival Analysis For Concrete Bridge Decks, 2019 University of Wisconsin-Milwaukee
Conditional Survival Analysis For Concrete Bridge Decks, Azam Nabizadeh, Habib Tabatabai, Mohammad A. Tabatabai
Civil and Environmental Engineering Faculty Articles
Bridge decks are a significant factor in the deterioration of bridges, and substantially affect long-term bridge maintenance decisions. In this study, conditional survival (reliability) analysis techniques are applied to bridge decks to evaluate the age at the end of service life using the National Bridge Inventory records. As bridge decks age, the probability of survival and the expected service life would change. The additional knowledge gained from the fact that a bridge deck has already survived a specific number of years alters (increases) the original probability of survival at subsequent years based on the conditional probability theory. The conditional expected ...
Quantifying Sleep Architecture For Pediatric Hypersomnia Conditions, 2019 Colorado School of Mines
Quantifying Sleep Architecture For Pediatric Hypersomnia Conditions, Alicia K. Colclasure
Biology and Medicine Through Mathematics Conference
No abstract provided.
A Bayesian Framework For Estimating Seismic Wave Arrival Time, 2019 University of Arkansas, Fayetteville
A Bayesian Framework For Estimating Seismic Wave Arrival Time, Hua Zhong
Theses and Dissertations
Because earthquakes have a large impact on human society, statistical methods for better studying earthquakes are required. One characteristic of earthquakes is the arrival time of seismic waves at a seismic signal sensor. Once we can estimate the earthquake arrival time accurately, the earthquake location can be triangulated, and assistance can be sent to that area correctly. This study presents a Bayesian framework to predict the arrival time of seismic waves with associated uncertainty. We use a change point framework to model the different conditions before and after the seismic wave arrives. To evaluate the performance of the model, we ...
Unified Methods For Feature Selection In Large-Scale Genomic Studies With Censored Survival Outcomes, Lauren Spirko-Burns, Karthik Devarajan
COBRA Preprint Series
One of the major goals in large-scale genomic studies is to identify genes with a prognostic impact on time-to-event outcomes which provide insight into the disease's process. With rapid developments in high-throughput genomic technologies in the past two decades, the scientific community is able to monitor the expression levels of tens of thousands of genes and proteins resulting in enormous data sets where the number of genomic features is far greater than the number of subjects. Methods based on univariate Cox regression are often used to select genomic features related to survival outcome; however, the Cox model assumes proportional ...
Automatic 13C Chemical Shift Reference Correction Of Protein Nmr Spectral Data Using Data Mining And Bayesian Statistical Modeling, Xi Chen
Theses and Dissertations--Molecular and Cellular Biochemistry
Nuclear magnetic resonance (NMR) is a highly versatile analytical technique for studying molecular configuration, conformation, and dynamics, especially of biomacromolecules such as proteins. However, due to the intrinsic properties of NMR experiments, results from the NMR instruments require a refencing step before the down-the-line analysis. Poor chemical shift referencing, especially for 13C in protein Nuclear Magnetic Resonance (NMR) experiments, fundamentally limits and even prevents effective study of biomacromolecules via NMR. There is no available method that can rereference carbon chemical shifts from protein NMR without secondary experimental information such as structure or resonance assignment.
To solve this problem, we ...
Quantifying Human Biological Age: A Machine Learning Approach, 2019 West Virginia University
Quantifying Human Biological Age: A Machine Learning Approach, Syed Ashiqur Rahman
Graduate Theses, Dissertations, and Problem Reports
Quantifying human biological age is an important and difficult challenge. Different biomarkers and numerous approaches have been studied for biological age prediction, each with its advantages and limitations. In this work, we first introduce a new anthropometric measure (called Surface-based Body Shape Index, SBSI) that accounts for both body shape and body size, and evaluate its performance as a predictor of all-cause mortality. We analyzed data from the National Health and Human Nutrition Examination Survey (NHANES). Based on the analysis, we introduce a new body shape index constructed from four important anthropometric determinants of body shape and body size: body ...
Real-Time Dengue Forecasting In Thailand: A Comparison Of Penalized Regression Approaches Using Internet Search Data, 2018 University of Massachusetts Amherst
Real-Time Dengue Forecasting In Thailand: A Comparison Of Penalized Regression Approaches Using Internet Search Data, Caroline Kusiak
Dengue fever affects over 390 million people annually worldwide and is of particu- lar concern in Southeast Asia where it is one of the leading causes of hospitalization. Modeling trends in dengue occurrence can provide valuable information to Public Health officials, however many challenges arise depending on the data available. In Thailand, reporting of dengue cases is often delayed by more than 6 weeks, and a small fraction of cases may not be reported until over 11 months after they occurred. This study shows that incorporating data on Google Search trends can improve dis- ease predictions in settings with severely ...
Modelling Heterogeneous Effects In Network Contagion: Evidence From The Steam Community, 2018 University of Pennsylvania
Modelling Heterogeneous Effects In Network Contagion: Evidence From The Steam Community, Henrique Laurino Dos Santos
Wharton Research Scholars
This study considers heterogeneous effects of reviews and social interactions on diffusion or contagion of new products in a networked setting, using a sample of interconnected public user profiles from the Steam Community. Ownership and reviews of two cult hit independent games – The Binding of Isaac: Rebirth, and To the Moon – are analyzed over a period of four years. This data was fit with a Hawkes Process Hazard Regression Model with exponential decay kernels for each game, yielding estimates of scale and duration of incremental heterogeneous actions within the network. This analysis finds strong, short term, additive, and marginally decreasing ...
Survival Analysis: A Modified Kaplan-Meir Estimator, 2017 Missouri State University
Survival Analysis: A Modified Kaplan-Meir Estimator, Justin A. Bancroft
MSU Graduate Theses
The popular Kaplan-Meir estimator has traditionally been used to great effect as a survival function estimator. However, the Kaplan-Meir estimator is dependent upon a maximum likelihood parameter estimator which may not be the best estimator in all cases. We modify the Kaplan-Meir estimator, based on a Bayes parameter estimation, in hopes of providing a more accurate survival estimator for small sample sizes. Core elements of survival analysis are presented, acting as a foundation from which to construct and compare our modified Kaplan-Meir estimator. It is hypothesized that our modified Kaplan-Meir estimator is generally more accurate than the standard Kaplan-Meir estimator ...
On The Estimation Of Penetrance In The Presence Of Competing Risks With Family Data, 2017 The University of Western Ontario
On The Estimation Of Penetrance In The Presence Of Competing Risks With Family Data, Daniel Prawira
Electronic Thesis and Dissertation Repository
In family studies, we are interested in estimating the penetrance function of the event of interest in the presence of competing risks. Failure to account for competing risks may lead to bias in the estimation of the penetrance function. In this thesis, three statistical challenges are addressed: clustering, missing data, and competing risks. We proposed the cause-specific model with shared frailty and ascertainment correction to account for clustering and competing risks along with ascertainment of families into study. Multiple imputation is used to account for missing data. The simulation study showed good performance of our proposed model in estimating the ...
Statistical Methods For Two Problems In Cancer Research: Analysis Of Rna-Seq Data From Archival Samples And Characterization Of Onset Of Multiple Primary Cancers, 2017 The University of Texas MD ANderson Cancer Center UTHealth Graduate School of Biomedical Sciences
Statistical Methods For Two Problems In Cancer Research: Analysis Of Rna-Seq Data From Archival Samples And Characterization Of Onset Of Multiple Primary Cancers, Jialu Li
UT GSBS Dissertations and Theses (Open Access)
My dissertation is focused on quantitative methodology development and application for two important topics in translational and clinical cancer research.
The first topic was motivated by the challenge of applying transcriptome sequencing (RNA-seq) to formalin-fixation and paraffin-embedding (FFPE) tumor samples for reliable diagnostic development. We designed a biospecimen study to directly compare gene expression results from different protocols to prepare libraries for RNA-seq from human breast cancer tissues, with randomization to fresh-frozen (FF) or FFPE conditions. To comprehensively evaluate the FFPE RNA-seq data quality for expression profiling, we developed multiple computational methods for assessment, such as the uniformity and continuity ...
Comparision Of Survival Curves Between Cox Proportional Hazards, Random Forests, And Conditional Inference Forests In Survival Analysis, Brandon Weathers, Richard Cutler Dr.
All Graduate Plan B and other Reports
Survival analysis methods are a mainstay of the biomedical fields but are finding increasing use in other disciplines including finance and engineering. A widely used tool in survival analysis is the Cox proportional hazards regression model. For this model, all the predicted survivor curves have the same basic shape, which may not be a good approximation to reality. In contrast the Random Survival Forests does not make the proportional hazards assumption and has the flexibility to model survivor curves that are of quite different shapes for different groups of subjects. We applied both techniques to a number of publicly available ...
Sidz Dc Article April Twenty, 2017 bepress university libraries
Sidz Dc Article April Twenty, Sidney Twentythree Sr., Ann Test
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Novel Computational Methods For Censored Data And Regression, 2017 University of Kentucky
Novel Computational Methods For Censored Data And Regression, Yifan Yang
Theses and Dissertations--Statistics
This dissertation can be divided into three topics. In the first topic, we derived a recursive algorithm for the constrained Kaplan-Meier estimator, which promotes the computation speed up to fifty times compared to the current method that uses EM algorithm. We also showed how this leads to the vast improvement of empirical likelihood analysis with right censored data. After a brief review of regularized regressions, we investigated the computational problems in the parametric/non-parametric hybrid accelerated failure time models and its regularization in a high dimensional setting. We also illustrated that, when the number of pieces increases, the discussed models ...
Survival Analysis In A Clinical Setting, 2016 Washington University in St. Louis
Survival Analysis In A Clinical Setting, Yunzhao Liu
Arts & Sciences Electronic Theses and Dissertations
With the fast paced advancement of modern medicine, cancer treatments have improved greatly over the past few decades; however, the overall survival rate has not improved for head neck squamous cell carcinoma (HNSCC). Traditionally, the general affected population of HNSCC was male over 50-60 years of age, whom have had history of alcohol and tobacco use. Conversely, in the recent decades, HNSCC has exhibited significant rise in younger patients, largely due to the increase in human papillomavirus (HPV) infection among young adults.
Generally, HPV as the most prevalent sexually transmitted disease, consisted of strains that do not cause harm to ...
Who Is Like Whom? Reclassification And Performance Patterns For Different Groupings Of English Learners, 2016 University of Massachusetts Amherst
Who Is Like Whom? Reclassification And Performance Patterns For Different Groupings Of English Learners, Molly M. Faulkner-Bond
Approximately 10 percent of the US K-12 population consists of English learners (ELs), or students who are learning English in addition to academic content in areas like English language arts (ELA) and mathematics. In addition to meeting the same academic content and performance standards set for all students, it is also a goal for ELs to be reclassified – i.e., to master English so that they can shed the EL label and participate in academic settings where English is used without needing special support. Working with a longitudinal cohort of ~28,000 ELs in grades 3 through 8 from one ...
Joint Modelling In Liver Transplantation, 2016 The University of Western Ontario
Joint Modelling In Liver Transplantation, Elizabeth M. Renouf
Electronic Thesis and Dissertation Repository
In the setting of liver transplantation, clinical trials and transplant registries regularly collect repeated measurements of clinical biomarkers which may be strongly associated with a time-to-event such as graft failure or disease recurrence. Multiple time-to-event outcomes are routinely collected. However, joint models are rarely used. This thesis will describe important considerations for joint modelling in the setting of liver transplantation. We will focus on transplant registry data from the United States. We develop a new tool for joint modelling in the context where a critical health event can be tracked in the longitudinal biomarker and often presents as a non-linear ...
Conditional Screening For Ultra-High Dimensional Covariates With Survival Outcomes, 2016 Michigan State University
Conditional Screening For Ultra-High Dimensional Covariates With Survival Outcomes, Hyokyoung Grace Hong, Jian Kang, Yi Li
The University of Michigan Department of Biostatistics Working Paper Series
Identifying important biomarkers that are predictive for cancer patients' prognosis is key in gaining better insights into the biological influences on the disease and has become a critical component of precision medicine. The emergence of large-scale biomedical survival studies, which typically involve excessive number of biomarkers, has brought high demand in designing efficient screening tools for selecting predictive biomarkers. The vast amount of biomarkers defies any existing variable selection methods via regularization. The recently developed variable screening methods, though powerful in many practical setting, fail to incorporate prior information on the importance of each biomarker and are less powerful in ...
A Transformation Class For Spatio-Temporal Survival Data With A Cure Fraction, 2016 Cleveland State University
A Transformation Class For Spatio-Temporal Survival Data With A Cure Fraction, Sandra M. Hurtado Rua, Dipak K. Dey
Mathematics Faculty Publications
We propose a hierarchical Bayesian methodology to model spatially or spatio-temporal clustered survival data with possibility of cure. A flexible continuous transformation class of survival curves indexed by a single parameter is used. This transformation model is a larger class of models containing two special cases of the well-known existing models: the proportional hazard and the proportional odds models. The survival curve is modeled as a function of a baseline cumulative distribution function, cure rates, and spatio-temporal frailties. The cure rates are modeled through a covariate link specification and the spatial frailties are specified using a conditionally autoregressive model with ...
Multilevel Analysis Of Individual, Neighborhood, And Health Care Facility Characteristics Associated With Achievement And Maintenance Of Hiv Viral Suppression Among Persons Newly Diagnosed With Hiv In New York City, 2016 Graduate Center, City University of New York
Multilevel Analysis Of Individual, Neighborhood, And Health Care Facility Characteristics Associated With Achievement And Maintenance Of Hiv Viral Suppression Among Persons Newly Diagnosed With Hiv In New York City, Ellen W. Wiewel
All Dissertations, Theses, and Capstone Projects
To investigate the effect of individual, health care facility, and neighborhood characteristics on achievement and maintenance of HIV viral suppression, among New York City residents aged 13 years and older diagnosed with HIV between 2006 and 2012.
I used individual-level data from the New York City HIV surveillance registry and Case Surveillance-Based Sampling, facility-level data from the surveillance registry, and neighborhood-level data from the U.S. Census and American Community Survey. The outcomes of interest were first viral suppression after diagnosis (Aims 1 and 3; ≤400 copies/mL) and virologic failure after first suppression among persons who achieved ...