Digital Commons Network^™

Factors That Affect The Rate Of Preterm Birth: An Examination Of The Inter-Related Impacts Of Social Determinants, Behavior And Physical Health Status, Krystal Michelle Hunter

Dissertations

The work seeks to examine the factors that have significant relationships to the rate of preterm birth (PTB) along with its cost to society.

There are four papers within this work. This purpose of the first paper is to measure the impact that healthy behaviors have on the rate of PTB when modeled with other factors like household demographics, community deprivation, chronic disease and mental health. This work finds that positive health behaviors has a negative relationship with PTB. The interaction between body mass index (BMI) and social class and its relationship to PTB is examined in the second paper. …

Exposing And Fixing Causes Of Inconsistency And Nondeterminism In Clustering Implementations, Xin Yin

Dissertations

Cluster analysis aka Clustering is used in myriad applications, including high-stakes domains, by millions of users. Clustering users should be able to assume that clustering implementations are correct, reliable, and for a given algorithm, interchangeable. Based on observations in a wide-range of real-world clustering implementations, this dissertation challenges the aforementioned assumptions.

This dissertation introduces an approach named SmokeOut that uses differential clustering to show that clustering implementations suffer from nondeterminism and inconsistency: on a given input dataset and using a given clustering algorithm, clustering outcomes and accuracy vary widely between (1) successive runs of the same toolkit, i.e., nondeterminism, and …

Crash Injury Severity Prediction With Artificial Neural Networks, Rima Abisaad

Dissertations

Motor vehicle crashes are one of our nation's most serious social, economic and health issues. They are the leading cause of death among children and young adults, killing approximately 1.35 million people each year. Providing a safe and efficient transportation system is the primary goal of transportation engineering and planning. To help reduce traffic fatalities and injuries on roadways, crash prediction models are used to forecast the injury severity of potential crashes and apply precautionary countermeasures accordingly. Most of these models are reactive as they use historical crash data to categorize crash-related factors. Recently, advancements have been made in developing …

Model Checks For Two-Sample Location-Scale, Atefeh Javidialsaadi

Dissertations

Two-sample location-scale refers to a model that permits a pair of standardized random variables to have a common distribution. This means that if X₁ and X₂ are two random variables with means µ₁ and µ₂ and standard deviations ?₁ and ?₂, then (X₁ - µ₁)/?₁ and (X₂ - µ₂)/?₂ have some common unspecified standard or base distribution F₀. Function-based hypothesis testing for these models refers to formal tests that would help determine whether or not two samples may have come from some location-scale …

On Performance Optimization And Prediction Of Parallel Computing Frameworks In Big Data Systems, Haifa Alquwaiee

Dissertations

A wide spectrum of big data applications in science, engineering, and industry generate large datasets, which must be managed and processed in a timely and reliable manner for knowledge discovery. These tasks are now commonly executed in big data computing systems exemplified by Hadoop based on parallel processing and distributed storage and management. For example, many companies and research institutions have developed and deployed big data systems on top of NoSQL databases such as HBase and MongoDB, and parallel computing frameworks such as MapReduce and Spark, to ensure timely data analyses and efficient result delivery for decision making and business …

Statistics-Based Anomaly Detection And Correction Method For Amazon Customer Reviews, Ishani Chatterjee

Dissertations

People nowadays use the Internet to project their assessments, impressions, ideas, and observations about various subjects or products on numerous social networking sites. These sites serve as a great source of gathering information for data analytics, sentiment analysis, natural language processing, etc. The most critical challenge is interpreting this data and capturing the sentiment behind these expressions. Sentiment analysis is analyzing, processing, concluding, and inferencing subjective texts with the views. Companies use sentiment analysis to understand public opinions, perform market research, analyze brand reputation, recognize customer experiences, and study social media influence. According to the different needs for aspect granularity, …

Machine Learning Techniques For Network Analysis, Irfan Lateef

Dissertations

The network's size and the traffic on it are both increasing exponentially, making it difficult to look at its behavior holistically and address challenges by looking at link level behavior. It is possible that there are casual relationships between links of a network that are not directly connected and which may not be obvious to observe. The goal of this dissertation is to study and characterize the behavior of the entire network by using eigensubspace based techniques and apply them to network traffic engineering applications.

A new method that uses the joint time-frequency interpretation of eigensubspace representation for network statistics …

Coherent Control Of Dispersive Waves, Jimmie Adriazola

Dissertations

This dissertation addresses some of the various issues which can arise when posing and solving optimization problems constrained by dispersive physics. Considered here are four technologically relevant experiments, each having their own unique challenges and physical settings including ultra-cold quantum fluids trapped by an external field, paraxial light propagation through a gradient index of refraction, light propagation in periodic photonic crystals, and surface gravity water waves over shallow and variable seabeds. In each of these settings, the physics can be modeled by dispersive wave equations, and the technological objective is to design the external trapping fields or propagation media such …

Private And Federated Deep Learning: System, Theory, And Applications For Social Good, Han Hu

Dissertations

During the past decade, drug abuse continues to accelerate towards becoming the most severe public health problem in the United States. The ability to detect drug­abuse risk behavior at a population scale, such as among the population of Twitter users, can help to monitor the trend of drug­abuse incidents. However, traditional methods do not effectively detect drug­abuse risk behavior in tweets, mainly due to the sparsity of such tweets and the noisy nature of tweets. In the first part of this dissertation work, the task of classifying tweets as containing drug­abuse risk behavior or not, is studied. Millions of public …

Improving Programming Learners’ Experience Through Interactive Computer Tutor Based Moocs, Ruiqi Shen

Dissertations

With the large demand for technology workers all around the world, more people are learning programming. Studies show that human tutoring is the most effective way to learn for novice programmers. However, problems such as the inaccessibility to physical classes, prohibitive costs, and the lack of educators may limit students' opportunities to learn from these resources. Additionally, because programming is a skill requiring continuous practice and immediate feedback, simply listening to lectures may not be sufficient to learn effectively. This increases the inconvenience of learners who use online learning tools such as Massive Open Online Courses (MOOCs).

In recent years, …

Iii-Nitride Nanostructures: Photonics And Memory Device Applications, Barsha Jain

Dissertations

III-nitride materials are extensively studied for various applications. Particularly, III-nitride-based light-emitting diodes (LEDs) have become the major component of the current solid-state lighting (SSL) technology. Current III-nitride-based phosphor-free white color LEDs (White LEDs) require an electron blocking layer (EBL) between the device active region and p-GaN to control the electron overflow from the active region, which has been identified as one of the primary reasons to adversely affect the hole injection process. In this dissertation, the effect of electronically coupled quantum well (QW) is investigated to reduce electron overflow in the InGaN/GaN dot-in-a-wire phosphor-free white LEDs and to improve the …

Hydrophobically Modified Isosorbide Dimethacrylates As Biomaterials For Bisphenol A Free Dental Fillings, Bilal Marie

Dissertations

Amalgam and Bisphenol A glycerolate dimethacrylate (BisGMA) are the main dental filling materials in use today. Because of the negative perception of amalgam and its lower esthetic appeal, as well as the desire to replace the endocrine disruptor Bisphenol A, which is the building block of BisGMA, there has been a critical need to search for safer alternatives to these dental filling materials.

Isosorbide is a sugar-based molecule generally recognized as safe. It has been extensively studied as a replacement to the Bisphenol A core in various materials. However, isosorbide is extremely hygroscopic, and water uptake in dental fillings causes …

Ecological Restoration Parks In Xi’An, China: An Evolving Type, Han Yan

Dissertations

This dissertation examines four urban ecological restoration projects used as public spaces in the city of Xi'an, China. The overall goal is to understand the social and ecological implications of the site features at both design and planning scale and define what is ecological restoration in China's urban context. The result of the research shows that the top-down planning initiatives approach for establishing ecological restoration sites in urban areas that meet the need for more public open space in addition to restoring healthy urban ecological systems is very different from the definition of what is traditionally understood as "ecological restoration". …

A Vacuum-Driven Distillation Technology Of Aqueous Solutions And Mixtures, Guo Guangyu

Dissertations

Distillation of aqueous solutions and aqueous mixtures has vast industrial applications, including desalination, wastewater treatment, and fruit juice concentration. Currently, two major distillation technologies are adopted in the industry, membrane separation and thermal distillation. However, both of them face certain inevitable drawbacks. Membrane separation has disadvantages as relying on high-grade energy, requiring membrane, fouling problem, narrow treatment range, limited scalability, and vibrating and noisy operating conditions. Traditional thermal distillation technologies can avoid above concerns but has other shortcomings, such as relatively low energy efficiency and yield rate, complicated and bulky system structure, and scaling problem.

This project proposes an innovative …

On Resource-Efficiency And Performance Optimization In Big Data Computing And Networking Using Machine Learning, Wuji Liu

Dissertations

Due to the rapid transition from traditional experiment-based approaches to large-scale, computational intensive simulations, next-generation scientific applications typically involve complex numerical modeling and extreme-scale simulations. Such model-based simulations oftentimes generate colossal amounts of data, which must be transferred over high-performance network (HPN) infrastructures to remote sites and analyzed against experimental or observation data on high-performance computing (HPC) facility. Optimizing the performance of both data transfer in HPN and simulation-based model development on HPC is critical to enabling and accelerating knowledge discovery and scientific innovation. However, such processes generally involve an enormous set of attributes including domain-specific model parameters, network transport …

Electro-Chemo-Mechanics Of The Interfaces In 2d-3d Heterostructure Electrodes, Vidushi Sharma

Dissertations

Unique heterostructure electrodes comprising two-dimensional (2D) materials and bulk three dimensional (3D) high-performance active electrodes are recently synthesized and experimentally tested for their electrochemical performance in metal-ion batteries. Such electrodes exhibit long cycle life while they also retain high-capacity inherent to the active electrode. The role of 2D material is to provide a supportive mesh that allows buffer space for volume expansions upon ion intercalation in the active material and establishes a continuous electronic contact. Therefore, the binding strength between both materials is crucial for the success of such electrodes. Furthermore, battery cycles may bring about phase transformations in the …

Experimental And Computational Studies Of Functionalized Carbon Nanotubes For Use In Energy Storage Devices And Membranes, Emine S. Karaman

Dissertations

Electrolytes with good interfacial stability are a crucial component of any electrochemical device. The development of novel gel polymer electrolytes (GEs) with good interface stability and better manufacturability is important for the development of the next generation electrochemical devices. Gel electrolytes are hybrid electrolyte materials, combining benefits of both liquid and solid systems. Compared with liquid and solid electrolytes, GEs open new design opportunities and do not require rigorous encapsulation methods. In this dissertation, studies on functionalized carbon nanotubes (fCNTs) and graphene oxide (GO) doped polyvinyl alcohol (PVA) based gel electrolytes (GEs) are reported. The ionic conductivity and mechanical strength …

A Practical Approach To Automated Software Correctness Enhancement, Aleksandr Zakharchenko

Dissertations

To repair an incorrect program does not mean to make it correct; it only means to make it more-correct, in some sense, than it is. In the absence of a concept of relative correctness, i.e. the property of a program to be more-correct than another with respect to a specification, the discipline of program repair has resorted to various approximations of absolute (traditional) correctness, with varying degrees of success. This shortcoming is concealed by the fact that most program repair tools are tested on basic cases, whence making them absolutely correct is not clearly distinguishable from making them relatively more-correct. …

Characterization Of The Ch Addition Product From Meta- And Ortho-Xylene + Ch Reaction And Direct Experimental Observation Of The Tetrabromine Cluster Br4 Using Synchrotron Photoionization Mass Spectrometry, Rory R. Mcclish

Master's Theses

This thesis is centered on the use of a unique gas-phase spectroscopy technique to characterize products and elucidate reaction mechanisms. Experiments were carried out at the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source located at the Lawrence Berkeley National Laboratory in Berkeley, CA. Computational work was performed on the scientific supercomputer at USF to supplement experimental findings. Chapter 1 contextualizes the work spurred in response to the deleterious interactions of anthropogenic emissions on Earth’s climate. Chapter 2 describes the theoretical manipulations foundational to the experimental design and interpretation. Chapter 3 delves into the physical details of the experimental …

Parameter Estimation And Inference Of Spatial Autoregressive Model By Stochastic Gradient Descent, Gan Luan

Dissertations

Stochastic gradient descent (SGD) is a popular iterative method for model parameter estimation in large-scale data and online learning settings since it goes through the data in only one pass. While SGD has been well studied for independent data, its application to spatially-correlated data largely remains unexplored. This dissertation develops SGD-based parameter estimation and statistical inference algorithms for the spatial autoregressive (SAR) model, a common model for spatial lattice data.

This research contains three parts. (I) The first part concerns SGD estimation and inference for the SAR mean regression model. A new SGD algorithm based on maximum likelihood estimator (MLE) …

Machine Learning And Computer Vision In Solar Physics, Haodi Jiang

Dissertations

In the recent decades, the difficult task of understanding and predicting violent solar eruptions and their terrestrial impacts has become a strategic national priority, as it affects the life of human beings, including communication, transportation, the power grid, national defense, space travel, and more. This dissertation explores new machine learning and computer vision techniques to tackle this difficult task. Specifically, the dissertation addresses four interrelated problems in solar physics: magnetic flux tracking, fibril tracing, Stokes inversion and vector magnetogram generation.

First, the dissertation presents a new deep learning method, named SolarUnet, to identify and track solar magnetic flux elements in …

Itraconazole Nanocomposites Prepared Via Rotary Evaporator Drying Of Nanomilled Suspensions, Alexander Santos Coelho

Theses

The aim of this study is to explore the feasibility of rotary evaporation for drying wetmilled drug suspensions as a novel approach to produce drug nanocomposites that exhibit fast redispersion and immediate drug release. To this end, the physical stability of the nanomilled itraconazole (drug) suspensions, a.k.a., nanosuspensions, during the milling and storage; the drying of the itraconazole nanosuspensions via the rotary evaporator; and the type/loading of various polymers/surfactants (dispersants) on aqueous redispersion and drug release from the nanocomposites were examined. Our results suggest that smaller drug particle size, owing to nanomilling, and smaller nanocomposite particle size, owing to optimized …

Soil Organic Carbon In Maine, Its Responses To Biochar Addition, And Climate Change, Xue Bai

Electronic Theses and Dissertations

Soil organic carbon (SOC), as one of the largest C pools in terrestrial ecosystems, plays a key role in governing soil ecosystem processes and climate regulation. Climate change concerns have resulted in a rapidly growing interest in understanding the potential for natural climate solutions (NCS) that include enhancing SOC sequestration and reduce net atmospheric greenhouse gas (GHG) emissions. This research focused on addressing information needs about SOC in Maine, specifically in evaluating available soil databases to accurately quantify SOC density and concentration, and study the response of selected representative Maine soils to biochar amendments under a changing climate.

Maine SOC …

Electric-Field-Driven Processes In Multiphase Fluid Systems, Qian Lei

Dissertations

Advantages of using electric fields in miniaturized apparatuses for a wide range of applications are revealed by numerous experimental and theoretical studies over the last several decades as it offers a simple and efficient method for manipulation of multiphase fluid systems. This approach is considered to be especially beneficial for control of boiling processes and colloidal suspensions considered in the presented work.

Boiling. Today's trends for enhancing boiling heat transfer in terrestrial and space applications focus on removal of bubbles to prevent formation of a vapor layer over the surface at a high overheat. In contrast, this dissertation presents a …

Dependent Censoring In Survival Analysis, Zhongcheng Lin

Dissertations

This dissertation mainly consists of two parts. In the first part, some properties of bivariate Archimedean Copulas formed by two time-to-event random variables are discussed under the setting of left censoring, where these two variables are subject to one left-censored independent variable respectively. Some distributional results for their joint cdf under different censoring patterns are presented. Those results are expected to be useful in both model fitting and checking procedures for Archimedean copula models with bivariate left-censored data. As an application of the theoretical results that are obtained, a moment estimator of the dependence parameter in Archimedean copula models is …

Elementary Teacher Experiences With English Language Learners With Special Education Needs In New York, Colleen Ann Cahill

Theses and Dissertations

This qualitative study aimed to understand teacher experiences working with English language learners (ELL) with or suspected of having a learning disability. This study also addressed the current problem of ELL students concurrently being under and over classified as needing special education services. This study explored the experiences of elementary school teachers in the state of New York. The participants were from different school districts within New York State. The participants all had experience teaching students who were designated ELL who were currently in the process of response to intervention (RTI) or had already been referred and classified as having …

Prescreening For Dementia In The Older Adult Surgical Population: A Systematic Review, Brittany M. Wallin

Master's Theses, Dissertations, Graduate Research and Major Papers Overview

In the older adult surgical population, individuals with dementia are at higher risk for postoperative delirium (POD) which has been associated with a decline in patients’ postoperative function, longer hospital length of stay (LOS), and increased morbidity and mortality (Kassahun, 2018). Although the neuropathology of POD remains not fully understood, the pathology of dementia and Alzheimer’s disease (AD) in particular, has been highly researched. Alterations in dementia-associated biomarkers are seen up to a decade before clinical signs and symptoms are evident resulting in difficulty predicting POD in the older adult population (Olsson et al., 2016). Amyloid-ß 1-42 (Aß42), a dementia-associated …

Afflictionary: Defining Disability And Chronic Illness Through Poetic Dictionary Entries, Jaime Chernoch

Graduate Masters Theses

Afflictionary, Defining Disability and Chronic Illness Through Poetic Dictionary Entries is a poetry collection that uses the format of a dictionary to explore individualized experiences of both medical and non-medical words. The definitions and reference quotes that come before the poems come from the Oxford English Dictionary and various medical journals. The quotes act as a prompt or framework that helped shape the personal entries. They may echo the content in the poems, be placed in opposition, or complicate our understanding of the word. Some of the words list multiple years of personal entries which shows the chronic and recurrent …

Meaning-Making Dynamics Of Job Interview Performances, Jacquelyn K. Bertman

Graduate Masters Theses

Behavioral interviewing has become a popular technique used across fields to assess the fitness of job seekers (Roulin & Bangerter, 2012; Powers, 2000). This particular style of interviewing calls on the interviewee to narrate their prior experiences in the workforce, with the idea that past behavior on the job is prelude to future job performance. The answers (stories) follow a specific format in order to be considered successful, one that adheres to the style and organization of the dominant Discourse (Gee, 1989). However, storytelling is a culturally situated practice and candidates from diverse backgrounds may construct their narratives outside of …

Acknowledgment Of Culture And Stereotypes: Black Participants’ Perceptions Of Specific Therapist Behaviors, Tsotso T. Ablorh

Graduate Masters Theses

Mental health disparities for Black people of diverse ethnicities compared to people of other racial identities has been well-documented (Alegría et al., 2008; Maura & Weisman de Mamani, 2017). Research addressing this pervasive systemic and interpersonal problem often focuses on client-related factors that create or intensify barriers to care. However clinician-related factors (i.e., racial identity, multicultural training, implicit biases, behavior, etc.) also have a significant impact on barriers to care, retention in therapy, and clinical outcomes for people of African descent (Larrison & Schoppelrey, 2011; Owen, Imel, Adelson, & Rodolfa, 2012). Researchers suggest that the favoring of historically white perspectives, …