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Model-Based Deep Learning For Computational Imaging, Xiaojian Xu

McKelvey School of Engineering Graduate Student Theses & Dissertations

This dissertation addresses model-based deep learning for computational imaging. The motivation of our work is driven by the increasing interests in the combination of imaging model, which provides data-consistency guarantees to the observed measurements, and deep learning, which provides advanced prior modeling driven by data. Following this idea, we develop multiple algorithms by integrating the classical model-based optimization and modern deep learning to enable efficient and reliable imaging. We demonstrate the performance of our algorithms by validating their performance on various imaging applications and providing rigorous theoretical analysis.

The dissertation evaluates and extends three general frameworks, plug-and-play priors (PnP), regularized …

Nanoscale Interfacial Control Of Ion Behaviors And Caco3 Formation In Environmental Systems, Yaguang Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Interfaces in environmental systems can change the distribution of pollutants and nutrients, determine the fate and transport of nanoparticles, and affect the efficiency of engineering projects. Complex interactions, including electrostatic interactions, Van der Waals interactions, chemical interactions, and ion-surface specific interactions, can all contribute to different ion, ion-pair, and nanoparticle formations near interfaces. Although environmental interfaces play critical roles, only a limited number of studies have considered the nanoscale picture of how they control ions and nanoparticles. Thus, this dissertation addresses three research questions: (1) How does sulfate chemically interact with calcium carbonate (CaCO3) during its heterogeneous formation on quartz …

Five Things You Should Know This Week, Georgia Southern University

A Few Things You Should Know This Week (2020-2023)

• GS Behavioral Assessment Team (BAT) is Available to Identify Resources and Appropriate Interventions
• State of Georgia Government Vehicle Insurance ID Card is Available Online
• Please be Aware of Projects and Office Moves Around our Campuses

Macro Barriers To Business And Innovation In Developing Economies: Evidence From Egyptian, Moroccan, And Tunisian Smes, Nizar Becheikh, Mohammed Bouaddi

Faculty Journal Articles

Investing in knowledge and innovation is recognised as a key driver of economic growth in any country. This paper contributes to the thin literature on innovation determinants in developing economies by empirically examining the impact of macro-level obstacles to business on small and medium-sized enterprises’ innovations in three Arab countries, namely, Egypt, Morocco, and Tunisia. While R&D emerged as the main factor that impacts positively and significantly the likelihood that firms innovate and succeed in producing a diverse set of product and process innovations, different combinations of other factors proved to affect innovation in each of the three countries.

Ell Cultural Inclusion Initiative, Julia L. Gidley

Masters Theses

This project draws on Maslow’s theory of motivation using his hierarchy as a framework, as well as Vygotsky’s sociocultural theory. This project aims to engage and involve English Language Learners (ELL) in the classroom by informing educators of strategies that help to find commonalities among students and cultivate communication between Native English Speakers and ELLs thus developing a culturally inclusive classroom. By building the relationships between the two student subgroups (ELLs and NESs) teachers will gain a class of students who have a well-developed world view, increase language acquisition, and develop a deep appreciation and respect for other cultures. Through …

Development Of Noninvasive Biomarkers For Cervical Spondylotic Myelopathy, Dinal Jayasekera

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cervical spondylotic myelopathy (CSM) represents the most common cause of chronic spinal cord injury (SCI) in adults. Many patients with symptomatic CSM will experience a decline in neurological function and consequently undergo surgical decompression. Unfortunately, surgeons are unable to adequately counsel patients about the benefits of surgery because the natural history of disease and outcome after decompression vary widely among patients. This can hinder the decision-making capacity of patients and physicians. Therefore, we require additional tools to help guide therapy and counsel patients with CSM. Noninvasive biomarkers present valuable potential as predictors of a patient’s recovery in the long term. …

Dynamic Continuous Distributed Constraint Optimization Problems, Khoi Hoang

McKelvey School of Engineering Graduate Student Theses & Dissertations

The Distributed Constraint Optimization Problem (DCOP) formulation is a powerful tool to model multi-agent coordination problems that are distributed by nature. The formulation is suitable for problems where the environment does not change over time and where agents seek their value assignment from a discrete domain. However, in many real-world applications, agents often interact in a more dynamic environment and their variables usually require a more complex domain. Thus, the DCOP formulation lacks the capabilities to model the problems in such dynamic and complex environments. To address these limitations, researchers have proposed Dynamic DCOPs (D-DCOPs) to model how DCOPs dynamically …

Tfa Inference: Using Mathematical Modeling Of Gene Expression Data To Infer The Activity Of Transcription Factors, Cynthia Ma

McKelvey School of Engineering Graduate Student Theses & Dissertations

Transcription factors (TFs) are a set of proteins that play a key role in the information processing system that enables a cell to respond to changes in internal and external state. By binding near a gene in a cell’s DNA, a TF can influence that gene’s expression level, triggering the appropriate increase or decrease in production levels of proteins that are needed to handle stressors like a change in nutrient availability or damage to the cell’s internal structures. Transcription factor activity (TFA) is a measure of how much effect a TF has on its target genes in a given sample …

Smart Sensing And Clinical Predictions With Wearables: From Physiological Signals To Mental Health, Ruixuan Dai

McKelvey School of Engineering Graduate Student Theses & Dissertations

Wearable devices such as smartwatches and wristbands are gaining adoption. Recent advances in technology in wearables enable remote health monitoring. However, there are challenges in exploiting wearables in healthcare applications. First, sensor readings from wearables are vulnerable to motion and noise artifacts. A robust pipeline is needed to extract reliable measurements from noisy signals. Second, while wearables support an increasing number of sensing modalities, there is a significant need to generate more clinically meaningful measurements with wearables. Finally, to incorporate wearables into clinical practice, we need to establish the link between wearable measurements and clinical outcomes, thus supporting clinical decisions. …

Scheduling For High Throughput And Small Latency In Parallel And Distributed Systems, Zhe Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Parallel and distributed systems are pervasive, such as web services, clouds, and cyber-physical systems. We often desire high throughput and small latency in the parallel and distributed system. However, since the system is distributed and the input is online, scheduling for high throughput while keeping the latency small is often challenging. In this dissertation, we developed scheduling algorithms, policies, and mechanisms to approach high throughput with small latency in various parallel and distributed applications. First, we developed AMCilk runtime system for running multi-programmed parallel jobs on many-processor machines. When running parallel jobs, the allocation of processors to the parallel jobs …

Human-Centered Machine Learning: Algorithm Design And Human Behavior, Wei Tang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Machine learning is increasingly engaged in a large number of important daily decisions and has great potential to reshape various sectors of our modern society. To fully realize this potential, it is important to understand the role that humans play in the design of machine learning algorithms and investigate the impacts of the algorithm on humans.

Towards the understanding of such interactions between humans and algorithms, this dissertation takes a human-centric perspective and focuses on investigating the interplay between human behavior and algorithm design. Accounting for the roles of humans in algorithm design creates unique challenges. For example, humans might …

Focused Ultrasound-Enabled Blood-Based Liquid Biopsy (Sonobiopsy) For Brain Disease Diagnosis, Christopher Pham Pacia

McKelvey School of Engineering Graduate Student Theses & Dissertations

Brain cancer severely threatens human health due to its disruption of neurological function, poor prognosis, and substantial reduction in quality of life. Glioblastoma (GBM) is the most devastating brain cancer; not only is it the most common malignant primary tumor in adults, but also it has a median survival of 14 months with a 5-year survival rate of less than 5%. Despite advances in multidisciplinary treatment that includes surgical resection, radiation therapy, and chemotherapy, almost all patients experience tumor progression and nearly universal mortality within 2 years. However, advances in patient care have suggested that the accurate diagnosis of molecular …

Environmental Fate Of Rna Interference Biopesticides, Ke Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Emerging agricultural biotechnology uses RNA interference (RNAi) to protect crops from pests. RNAi is a cellular mechanism in which double-stranded RNA (dsRNA) directs the degradation of the homologous messenger RNA (mRNA), leading to gene silencing and preventing the synthesis of essential proteins. As applied to agriculture, dsRNA biopesticides have been developed that can trigger RNAi inside of the pest tissues to cause reduced pest growth and/or increased pest mortality. When dsRNA biopesticides are released to receiving environments (e.g., agricultural soils and surface water), they pose potential ecological risks to non-target organisms. This dissertation aims to advance the understanding of the …

Design And Analysis Of Strategic Behavior In Networks, Sixie Yu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Networks permeate every aspect of our social and professional life.A networked system with strategic individuals can represent a variety of real-world scenarios with socioeconomic origins. In such a system, the individuals' utilities are interdependent---one individual's decision influences the decisions of others and vice versa. In order to gain insights into the system, the highly complicated interactions necessitate some level of abstraction. To capture the otherwise complex interactions, I use a game theoretic model called Networked Public Goods (NPG) game. I develop a computational framework based on NPGs to understand strategic individuals' behavior in networked systems. The framework consists of three …

Development Of Intravital Microscopy For Brain Imaging With Improved Spatiotemporal Coverage And Contrast, Yifeng Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Capitalizing on the Brownian motion of red blood cells, the distinct optical absorption spectra of oxy-hemoglobin and deoxy-hemoglobin, and the blood flow-induced signal decorrelation, multi-parametric photoacoustic microscopy (PAM) is capable of quantifying concentration of hemoglobin (CHb), blood oxygen saturation (sO2), and hemodynamics at the microscopic level via statistical, spectroscopic, and correlation analyses. Multi-parametric PAM has found broad biomedical applications. In fact, there are still much room to further improve the performance and imaging capability of multi-parametric PAM to meet the ever-increasing demanding requirements of biomedical research. To date, there are two main obstacles that prevent multi-parametric PAM from being more …

Mechanisms Of Primate Working Memory, Charles Damian Holmes

McKelvey School of Engineering Graduate Student Theses & Dissertations

One of the defining features of the behavior of many animal species is the ability to retain and utilize information from the environment even after it is gone. The encoding and utilization of information on short time scales is referred to as working memory. It is not yet fully understood how the brain accomplishes working memory.

This dissertation presents three studies that help to characterize the working memory system of primates. All three studies involve primates performing saccades during a spatial memory task. The first study demonstrates that while the local field potential power is contralaterally tuned (i.e., power is …

Characterization Of Smoke Particles Toward Improved Remote Sensing Retrievals And Chemical Transport Modeling, Chenchong Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Wildfires increase in extent, intensity, and frequency across the globe over the recent decades. The uncontrolled fires trigger cascading effects on local ecosystems and the fire emissions pose a higher risk to air quality and climate. Wildfire emissions contain a variety of trace gases and particulate matters. The particle-phase emissions, especially those light-absorbing species including black carbon (BC) and brown carbon (BrC), significantly affect the regional and global climate by modulating the radiative transfer phenomena in the atmosphere. A great discrepancy still exists between model- and observation-based estimates of aerosol-radiation interactions (ARI). The discrepancy is partially attributed to the mischaracterizations …

Modeling, Analysis, And Simulation To Reveal The Mechanisms Of Ciliary Beating, Louis Woodhams

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cilia are microscopic cellular appendages that help us breathe by clearing our airways, maintain the health of our central nervous system by circulating cerebrospinal fluid, and allow us to reproduce by transporting eggs and propelling sperm cells. Cilia even determine the asymmetry of our internal organs during embryonic development. However, the mechanisms underlying ciliary beating are not fully understood. Questions remain as to how arrays of the motor protein dynein generate the propulsive waveforms observed in cilia and how structural elements within the cilium and its connection to the cell deform during beating. In the current work, mathematical modeling, analysis, …

The Generation And Transport Of Charged Aerosols: Fundamental Study And Applications In Medicine And Energy Conversion, Hao Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Charged aerosols have significant implications in the field of functional material synthesis, pharmaceutical coating, and drug delivery. Electrospray systems are an effective methodology for generating highly charged monodispersed droplets in the size range from nanometer to micrometer. The prediction of surface charge, size and morphology of nanoparticles resulting from charged droplets are highly required for the precise control of nanoparticle properties and their effective utilization. However, the evolution of charged droplet is not well understood due to the existence of coulombic fission and ion evaporation processes. Thus, the goal of this dissertation is to elucidate how the precursor properties and …

Advancing The Portability, Field Of View, And Spatiotemporal Resolution Of Multi-Parametric Photoacoustic Microscopy, Fenghe Zhong

McKelvey School of Engineering Graduate Student Theses & Dissertations

Capable of structural, functional, molecular, and metabolic imaging with high spatial resolution in vivo, photoacoustic microscopy (PAM) is an emerging tool in biomedical research. Further, recent advances in multi-parametric acquisition and analysis make PAM uniquely capable of simultaneously mapping the total concentration of hemoglobin (CHb), oxygen saturation of hemoglobin (sO2), and blood flow speed. However, there are multiple major limitations, including, the large footprint, low imaging speed, limited imaging contrast, and insufficient axial resolution, which impedance its applications in basic and translational research. In this dissertation, I presented potential solutions to overcome the limitations above.In the first part of this …

Lead(Iv) Oxide In Drinking Water Systems: Formation, Dissolution, Redox-Driven Recrystallization, And Implications For Lead Control, Weiyi Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Lead (Pb) in tap water is mainly contributed by lead service lines (LSLs). The dissolved lead concentration is controlled by the solubilities of lead corrosion products that form on the inner surface of LSLs. Among these lead corrosion products, lead(IV) oxide (PbO2) has the lowest solubility and can maintain a low lead level when free chlorine is present. Current strategies to control the lead concentration include replacing the LSL, optimizing the water chemistry conditions, and using point-of-use (POU) filters. The present study investigated the effect of manganese (Mn) on the oxidation of the lead(II) carbonate solids by free chlorine, the …

Geometric Algorithms For Modeling Plant Roots From Images, Dan Zeng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Roots, considered as the ”hidden half of the plant”, are essential to a plant’s health and pro- ductivity. Understanding root architecture has the potential to enhance efforts towards im- proving crop yield. In this dissertation we develop geometric approaches to non-destructively characterize the full architecture of the root system from 3D imaging while making com- putational advances in topological optimization. First, we develop a global optimization algorithm to remove topological noise, with applications in both root imaging and com- puter graphics. Second, we use our topology simplification algorithm, other methods from computer graphics, and customized algorithms to develop a high-throughput …

Integrating Physical Models And Deep Priors For Computational Imaging, Yu Sun

McKelvey School of Engineering Graduate Student Theses & Dissertations

This dissertation addresses integrating physical models and learning priors for computational imaging. The motivation of our work is driven by the recent discussion of learning-based methods that solve the imaging inverse problem by directly learning a measurement-to-image mapping from the existing data: they achieve superior performance over the traditional model-based methods but lack the physical model to impose sufficient interpretation and guarantee of the final image. We adopt the classic statistical inference as the underlying formulation and integrate learning models as implicit image priors, such that our framework is able to simultaneously leverage physical models and learning priors. Additionally, the …

Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas

McKelvey School of Engineering Graduate Student Theses & Dissertations

Nonthermal plasmas offer a unique nonequilibrium environment that has been leveraged in a wide variety of applications in the fields of material processing, lighting, and waste management to name a few. In all of these cases, the plasma serves as a source of high energy electrons, ions, reactive gas species, and radicals that interact in several ways with surfaces brought into contact with the plasma. Specifically, nonthermal plasmas have been shown to be very successful in achieving continuous, high-throughput, monodisperse nanocrystals of a wide variety of materials. The crystallinity of nanoparticles synthesized in nonthermal plasmas can be attributed to the …

Intrinsic Cardiac Effects Of Severe Acute Respiratory Syndrome Coronavirus 2 In Coronavirus Disease 2019, Brittany Danielle Brumback

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cardiac arrhythmias, particularly ventricular arrhythmias, can be life-threatening and caused by both congenital genetic mutations and acquired cardiac injury. My thesis work was originally focused on delineating the effects of genetic mutation-driven dysregulation of a protein called Hey2 in Brugada Syndrome, a complex disease characterized by a predisposition to dangerous arrhythmias originating in the right ventricular outflow tract. In response to the pandemic, my thesis work shifted toward understanding the mechanisms of cardiovascular injury in Coronavirus disease 2019 (COVID-19), which is associated with serious cardiovascular complications, including ventricular arrhythmias and sudden cardiac death as well as endothelial dysfunction and coagulopathies. …

Droplet Dynamics And Heat Transfer During Condensation On Lubricant-Infused Surfaces, Jianxing Sun

McKelvey School of Engineering Graduate Student Theses & Dissertations

Inspired by pitcher plants, a micro/nano- structured solid surface infused with low-surface-tension lubricant constitutes a novel class of biomimetic surfaces—lubricant-infused surfaces (LISs). Unlike solid hydrophobic and superhydrophobic surfaces, a LIS is “hemi-solid and hemi-liquid”. The thin lubricating film can extraordinarily decrease adhesion and avoid contact line pinning between the working fluid and the underlying solid, displaying many desirable properties, such as excellent liquid repellency, suppression of fouling, and self-healing. Hence, LISs are ideal for applications where liquids or contaminants must be efficiently removed from surfaces in harsh environments. For example, LISs can promote stable dropwise condensation of water or low-surface-tension …

Design Of Multi-Principal Element Materials Using A Combination Of First-Principles Calculations And Machine Learning, Zhaohan Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Multiple-principal element materials, including alloys (MPEAs), oxides and other compounds combine several elements on a sub-lattice, which increases the configurational entropy and contributes to their thermodynamic stability. The vast combinatorial design space of multi-principal element materials gives rise to diverse microstructures and unprecedent combination of properties. It also poses a challenge—how to rapidly screen MPEAs with stability and properties for targeted applications. Furthermore, fundamental composition-structure-property relationships in MPEAs are currently missing. In this dissertation, I have used MPEAs as a representative system and investigated the role of chemical composition on their phase-stability and mechanical properties. With a combination of first-principles …

Trauma Exposures Across The Life Course For Individuals Who Experience Incarceration, Maria Morrison

Brown School Graduate Student Theses and Dissertations

The U.S. incarcerates more people than any other country in the world, with 2.2 million people currently behind bars, 60% of whom are people of color. At the same time, there is an unprecedented political consensus to develop strategies for reducing the incarcerated population and safely returning the majority of incarcerated individuals to society. While there has been a substantial research focus on the potential of this population to commit acts of violence post-release, this tells only half the story. This dissertation hopes to provide a more complete picture of the role of violence in the lives of individuals released …

The Effect Of Off-Site Examination: A Natural Experiment After Covid-19, Whan Kyu Shin

Olin Business School Graduate Student Theses and Dissertations

I examine the effectiveness of off-site bank examinations by using the natural experiment during COVID-19. Exploiting the difference in the amount of soft information and in the effect of the change to off-site examination between the banks far from the supervisory field office and those near the field office, I find that distant banks increase asset risk regarding RWA to asset ratio and become less conservative in anticipating or preparing for future losses from loan portfolios. I also show that distant banks that adjust the loan portfolio to be riskier are less profitable, and the effect is prominent among the …

The Vulnerability Of A Poor Urban Neighborhood To Extreme Weather Disasters And The Role Of Ecosocial Work: The Case Of Tongja-Dong Jjokbang-Chon In Seoul, South Korea, Joonmo Kang

Brown School Graduate Student Theses and Dissertations

his study is an inquiry into the vulnerability of poor older adults living in the Tongja-dong jjokbang-chon, one of the last remaining informal settlements in Seoul, South Korea, to climate change-related disasters, particularly heat waves and cold waves; climate change’s impact on their livelihoods; and the role of social work in responding to these challenges. Even though the harsh living conditions and the sufferings of those living in jjokbang-chon residents during extreme weather is constantly highlighted in the media, there is a dearth of empirical research focusing on the vulnerabilities of marginalized communities living in jjokbang-chon to extreme weather and …