Digital Commons Network^™

Supervisory Impact On Counselor-In-Training Wellness, Erin Brumfield Grima

Dissertations

Counselors being able to engage in self-care practices to establish and maintain their wellness is a well-documented need. The risks of neglecting self-care are also well documented, yet counselors struggle to engage in consistent self-care practices (Baker & Gabriel, 2021; Posluns & Gall, 2020). When demand for counselors is constant (Bureau of Labor Statistics, U.S. Department of Labor, 2020) an examination of how to impact counselor wellness through supervision discussion of self-care is needed. The purpose of the study was to examine supervision discussion of self-care, support of mastery of counselors-in-training’s emotions and any resulting impact on counselor wellness. Data …

Molecular Mechanisms Of Amyloid-Like Fibril Formation, Sharareh Jalali

Dissertations

Proteins play a critical role in living systems by performing most of the functions inside cells. The latter is determined by the protein's three-dimensional structure when it is folded in its native state. However, under pathological conditions, proteins can misfold and aggregate, accounting for the formation of highly ordered insoluble assemblies known as amyloid fibrils. These assemblies are associated with diseases like Parkinson's and Alzheimer's. Strong evidence suggests that three mechanisms are critical for forming amyloid fibrils. These mechanisms are the nucleation of amyloid fibrils in solution (primary nucleation) as well as on the surface of existing fibrils (secondary nucleation) …

Exploring Topological Phonons In Different Length Scales: Microtubules And Acoustic Metamaterials, Ssu-Ying Chen

Dissertations

The topological concepts of electronic states have been extended to phononic systems, leading to the prediction of topological phonons in a variety of materials. These phonons play a crucial role in determining material properties such as thermal conductivity, thermoelectricity, superconductivity, and specific heat. The objective of this dissertation is to investigate the role of topological phonons at different length scales.

Firstly, the acoustic resonator properties of tubulin proteins, which form microtubules, will be explored The microtubule has been proposed as an analog of a topological phononic insulator due to its unique properties. One key characteristic of topological materials is the …

Models And Algorithms For Promoting Diverse And Fair Query Results, Md Mouinul Islam

Dissertations

Ensuring fairness and diversity in search results are two key concerns in compelling search and recommendation applications. This work explicitly studies these two aspects given multiple users' preferences as inputs, in an effort to create a single ranking or top-k result set that satisfies different fairness and diversity criteria. From group fairness standpoint, it adapts demographic parity like group fairness criteria and proposes new models that are suitable for ranking or producing top-k set of results. This dissertation also studies equitable exposure of individual search results in long tail data, a concept related to individual fairness. First, the dissertation focuses …

Quantifying Balance: Computational And Learning Frameworks For The Characterization Of Balance In Bipedal Systems, Kubra Akbas

Dissertations

In clinical practice and general healthcare settings, the lack of reliable and objective balance and stability assessment metrics hinders the tracking of patient performance progression during rehabilitation; the assessment of bipedal balance plays a crucial role in understanding stability and falls in humans and other bipeds, while providing clinicians important information regarding rehabilitation outcomes. Bipedal balance has often been examined through kinematic or kinetic quantities, such as the Zero Moment Point and Center of Pressure; however, analyzing balance specifically through the body's Center of Mass (COM) state offers a holistic and easily comprehensible view of balance and stability.

Building upon …

Advanced Traffic Video Analytics For Robust Traffic Accident Detection, Hadi Ghahremannezhad

Dissertations

Automatic traffic accident detection is an important task in traffic video analysis due to its key applications in developing intelligent transportation systems. Reducing the time delay between the occurrence of an accident and the dispatch of the first responders to the scene may help lower the mortality rate and save lives. Since 1980, many approaches have been presented for the automatic detection of incidents in traffic videos. In this dissertation, some challenging problems for accident detection in traffic videos are discussed and a new framework is presented in order to automatically detect single-vehicle and intersection traffic accidents in real-time.

First, …

Learning Representations For Effective And Explainable Software Bug Detection And Fixing, Yi Li

Dissertations

Software has an integral role in modern life; hence software bugs, which undermine software quality and reliability, have substantial societal and economic implications. The advent of machine learning and deep learning in software engineering has led to major advances in bug detection and fixing approaches, yet they fall short of desired precision and recall. This shortfall arises from the absence of a 'bridge,' known as learning code representations, that can transform information from source code into a suitable representation for effective processing via machine and deep learning.

This dissertation builds such a bridge. Specifically, it presents solutions for effectively learning …

Fortifying Robustness: Unveiling The Intricacies Of Training And Inference Vulnerabilities In Centralized And Federated Neural Networks, Guanxiong Liu

Dissertations

Neural network (NN) classifiers have gained significant traction in diverse domains such as natural language processing, computer vision, and cybersecurity, owing to their remarkable ability to approximate complex latent distributions from data. Nevertheless, the conventional assumption of an attack-free operating environment has been challenged by the emergence of adversarial examples. These perturbed samples, which are typically imperceptible to human observers, can lead to misclassifications by the NN classifiers. Moreover, recent studies have uncovered the ability of poisoned training data to generate Trojan backdoored classifiers that exhibit misclassification behavior triggered by predefined patterns.

In recent years, significant research efforts have been …

Bacterial Motion And Spread In Porous Environments, Yasser Almoteri

Dissertations

Micro-swimmers are ubiquitous in nature from soil and water to mammalian bodies and even many technological processes. Common known examples are microbes such as bacteria, micro-algae and micro-plankton, cells such as spermatozoa and organisms such as nematodes. These swimmers live and have evolved in multiplex environments and complex flows in the presence of other swimmers and types, inert particles and fibers, interfaces and non-trivial confinements and more. Understanding the locomotion and interactions of these individual micro-swimmers in such impure viscous fluids is crucial to understanding the emergent dynamics of such complex systems, and to further enabling us to control and …

Diversification And Fairness In Top-K Ranking Algorithms, Mahsa Asadi

Dissertations

Given a user query, the typical user interfaces, such as search engines and recommender systems, only allow a small number of results to be returned to the user. Hence, figuring out what would be the top-k results is an important task in information retrieval, as it helps to ensure that the most relevant results are presented to the user. There exists an extensive body of research that studies how to score the records and return top-k to the user. Moreover, there exists an extensive set of criteria that researchers identify to present the user with top-k results, and result diversification …

Human-Ai Complex Task Planning, Sepideh Nikookar

Dissertations

The process of complex task planning is ubiquitous and arises in a variety of compelling applications. A few leading examples include designing a personalized course plan or trip plan, designing music playlists/work sessions in web applications, or even planning routes of naval assets to collaboratively discover an unknown destination. For all of these aforementioned applications, creating a plan requires satisfying a basic construct, i.e., composing a sequence of sub-tasks (or items) that optimizes several criteria and satisfies constraints. For instance, in course planning, sub-tasks or items are core and elective courses, and degree requirements capture their complex dependencies as constraints. …

Program Analysis For Android Security And Reliability, Sydur Rahaman

Dissertations

The recent, widespread growth and adoption of mobile devices have revolutionized the way users interact with technology. As mobile apps have become increasingly prevalent, concerns regarding their security and reliability have gained significant attention. The ever-expanding mobile app ecosystem presents unique challenges in ensuring the protection of user data and maintaining app robustness. This dissertation expands the field of program analysis with techniques and abstractions tailored explicitly to enhancing Android security and reliability. This research introduces approaches for addressing critical issues related to sensitive information leakage, device and user fingerprinting, mobile medical score calculators, as well as termination-induced data loss. …

Fluid Dynamics Of Interacting Particles: Bouncing Droplets And Colloid-Polymer Mixtures, Lauren Barnes

Dissertations

Interacting particles are a common theme across various physical systems, particularly on the atomic and sub-atomic scales. While these particles cannot be seen with the human eye, insight into such systems can be gained by observing macroscopic systems whose physical behavior is similar. This dissertation consists of three different chapters, each presenting a different problem related to interacting particles, as follows:

Chapter 1 explores chaotic trajectories of a droplet bouncing on the surface of a vertically vibrating fluid bath, with a simple harmonic force acting on the droplet. The bouncing droplet system has attracted recent interest because it exhibits behaviors …

Boundary Integral Equation Methods For Superhydrophobic Flow And Integrated Photonics, Kosuke Sugita

Dissertations

This dissertation presents fast integral equation methods (FIEMs) for solving two important problems encountered in practical engineering applications.

The first problem involves the mixed boundary value problem in two-dimensional Stokes flow, which appears commonly in computational fluid mechanics. This problem is particularly relevant to the design of microfluidic devices, especially those involving superhydrophobic (SH) flows over surfaces made of composite solid materials with alternating solid portions, grooves, or air pockets, leading to enhanced slip.

The second problem addresses waveguide devices in two dimensions, governed by the Helmholtz equation with Dirichlet conditions imposed on the boundary. This problem serves as a …

Colloidal Behavior Of Nanobubbles And Their Application In Enhancing Plant Growth: Mechanisms Of Nanobubble Interactions With Microbial And Soil Species, Shan Xue

Dissertations

Climate change has resulted in increasing uncertainties of water resources and disturbance on agricultural activities. For example, the shortage of water resources, land erosion and pollution from runoff significantly affect agricultural sustainability. This dissertation research focuses on the fundamental studies of nanobubble (NB) water and explores the benefits for irrigation to enhance plant germination and growth. Unlike bulk bubbles, NBs exhibit prolonged stability in water and possess large surface areas that facilitate efficient mass transfer and potential tailored reactions (e.g., disinfection). However, the enhancement mechanisms for NBs on seed germination and plant growth remain elusive.

This research first evaluated the …

Data-Driven 2d Materials Discovery For Next-Generation Electronics, Zeyu Zhang

Dissertations

The development of material discovery and design has lasted centuries in human history. After the concept of modern chemistry and material science was established, the strategy of material discovery relies on the experiments. Such a strategy becomes expensive and time-consuming with the increasing number of materials nowadays. Therefore, a novel strategy that is faster and more comprehensive is urgently needed. In this dissertation, an experiment-guided material discovery strategy is developed and explained using metal-organic frameworks (MOFs) as instances. The advent of 7r-stacked layered MOFs, which offer electrical conductivity on top of permanent porosity and high surface area, opened up new …

Variable Resolution Smoothed Particle Hydrodynamics Schemes For 2-D And 3-D Viscous Flows, Francesco Ricci

Dissertations

Smoothed Particle Hydrodynamics (SPH) is a Lagrangian particle-based method for the numerical solution of the partial differential equations that govern the motion of fluids. The main aim of this thesis work is to better enable the applicability of SPH to problems involving multi-scale fluid dynamics. In the first part of the thesis, the capability of the SPH method to simulate three-dimensional isotropic turbulence is investigated with a detailed comparison of Lagrangian and Eulerian SPH formulations. The main reason for this first investigation is to provide an assessment of the error introduced by the particle disorder on the SPH discrete operators …

Computational And Experimental Investigation Of Elemental Sulfur And Polysulfide, Jyoti Sharma

Dissertations

Petroleum processing results in the generation of significant quantities of elemental sulfur (S₈), leading to a surplus of sulfur worldwide. Despite its abundance and low cost, the use of sulfur in value-added organic compound synthesis is limited due to its unpredictable and misunderstood reactivity. This dissertation aims to address this issue by tackling it from two angles. Firstly, by utilizing Density Functional Theory (DFT) calculations, the reactivity of sulfur in the presence of nucleophiles is studied. This facilitates the identification of organic polysulfide intermediates that can be generated under different conditions, as well as the corresponding reactivity for …

Synergistic Effect Of Air Sparging In Separation Via Nano-Carbon Immobilized Membrane Distillation Process And Optimization, Mitun Chandra Bhoumick

Dissertations

Membrane distillation (MD) has gained significant popularity as a separation and purification technique in diverse domains, such as saline/brackish water treatment, organic recovery, and wastewater treatment. The objective of this research is to advance MD by developing a novel air sparged membrane distillation in treating saline water, recovering solvents, and achieving preconcentration. To optimize the flux and selectivity in membrane distillation, the study also employed a response surface method based on a central composite rotatable design.

In this study, a novel air-sparged membrane distillation (ASMD) is introduced for the treatment of saline water, utilizing a nanocarbon immobilized membrane. The performance …

On Explainability Of Neural Networks, Cem Benar

Dissertations

It is widely reported that deep neural networks outperform most competitors for a range of applications. The state-of-the-art neural networks have built-in inductive bias of architectural choices, regularizations, optimizer types, and initialization methods. Using inductive bias is intuitive to enhance the model approximation. Deep neural networks are mostly dense and heavily overparameterized. They tend to be biased towards low-rank solutions to reduce complexity and improve generalization performance, known as implicit regularization. The implicit regularization as observed in specific architectures and various real-world data sets suggests to overparameterize neural networks judiciously and learn compressed representations (lower rank approximation) with improved performance. …

Toward Smart And Efficient Scientific Data Management, Jinzhen Wang

Dissertations

Scientific research generates vast amounts of data, and the scale of data has significantly increased with advancements in scientific applications. To manage this data effectively, lossy data compression techniques are necessary to reduce storage and transmission costs. Nevertheless, the use of lossy compression introduces uncertainties related to its performance. This dissertation aims to answer key questions surrounding lossy data compression, such as how the performance changes, how much reduction can be achieved, and how to optimize these techniques for modern scientific data management workflows.

One of the major challenges in adopting lossy compression techniques is the trade-off between data accuracy …

Integrated Land Use And Transportation Modeling Considering The Impact Of Autonomous Vehicles, Roksana Asadi

Dissertations

The advent of autonomous urban mobility is expected to effect changes in land use patterns and urban development. A new framework for integrated land use and transportation system models that incorporate Autonomous Vehicles (AVs) and Shared Autonomous Vehicles (SAVs) will be needed to investigate the development of transportation and land use plans and policies. This study aims to analyze the impacts of AVs and SAVs on land use changes by defming scenarios that consider different shares of these emerging transportation modes. Also, this study explores the corollary effects of various land use factors by applying them to a case study …

A Student Induction Program’S Impact On Young “Techies’” Purpose In Life And Its Effects On Their Well-Being: A Case Study Of Telangana, India, Ankit Shah

Dissertations

India's higher education system aims to develop well-rounded individuals with intellectual curiosity, a spirit of service, and a strong ethical foundation. However, the current state of technical higher education in India is criticized for mono-disciplinarity and rigid boundaries that do not provide an appropriate context for developing socially conscious individuals who make productive contributions to society. To address this growing concern, the Department of Higher Education in India introduced the Student Induction Program (SIP). The primary objective of the SIP is to foster purpose, which is not only meaningful to the students themselves but also to their nation; as such, …

Local Labor Markets Exposure To Artificial Intelligence, Greg Call

Dissertations

As more evidence builds that artificial intelligence (AI) is a new general-purpose technology driving a fourth industrial revolution, scholars have begun to consider its potential impact on labor markets. The current debate among researchers is centered on whether AI will ultimately produce net new job gains or losses and what type of workers will benefit or be displaced. While no consensus has developed yet within the literature on AI’s predicted net employment impact, a majority of studies are forecasting that a skill-biased technological change will occur.

This exploratory study contributes to the current literature by operationalizing Webb’s objective patent-based AI …

Pláticas Liberadoras: Testimonios Of Chicana/O Elders En La Comunidad De San Diego, Gabriel Nunez-Soria

Dissertations

There is robust scholarship inquiring about many facets of critical consciousness (CC), most of which is centered around working with teens, youth, and educators. This study explored development of CC through testimonios of the lived experiences of eight Chicana/o elders in San Diego County. All eight of these elders participated in the Chicana/o movement during the late 1960s and early 1970s and carried these experiences with them into the present moment. Development of CC, the contextualized understandings of historical, social, and systemic aspects of our collective struggle against oppression through dialogue, reflection, and action, is a fundamental aspect of liberatory …

Advocating For Social Change: How A Human Service Nonprofit Organization Makes Sense Of Its Advocacy Successes And Failures, Megan Pontes

Dissertations

Nonprofit organizations (NPOs) are uniquely positioned to play a vital role in social change, and many integrate advocacy in their efforts. This dissertation examined how one human service nonprofit organization working to help the unhoused engaged in advocacy and advocacy evaluation using formal and informal methods. Through an in-depth case study of Think Dignity, a San Diego-based NPO engaged in the day-to-day work of social change, this research revealed how it developed its advocacy efforts, collaborated with partners, and assessed its successes and failures. Informed by the framework of social change leadership, the researcher conducted semi-structured interviews with Think Dignity. …

‘The Food Of The Home’ An Exploration Of Place And Practice Of Ordinary Women In Dublin City 1950-2000 On Irish Cuisine, Roann Byrne

Dissertations

Before the rise of restaurants and the accessibility of dining out, the home was where food engagement took place. In the recent surge of Irish Michelin restaurants, and our growing reputation for food culture, one element has been overlooked. Long before the great chefs and level of fine dining we have now – the heart of Irish food culture lay in the home. In the ongoing debate of what Irish cuisine is, we haven’t thought to look inwards, to the routes of our food engagement. This thesis seeks to understand the places, practices and engagement of ordinary women and food …

Climate Justice Perspectives And Strategies Implemented By Public Health Nurses And Their Community Partners, Jessica Leclair

Dissertations

The purpose of this dissertation was to understand PHN perceptions, strategies, and experiences with environmental and climate justice in the United States. In the first published study, a scoping review, I examined strategic actions nurses take to promote environmental justice through research, education, advocacy, and practice reported in peer-reviewed literature.

Interests And Decent Work’S Account Of Well-Being And Job Performance In A Lower Social Class Sample, Benjamin J. Wright

Dissertations

There is a need for more accurate information regarding the work-related experiences of individuals from lower social class backgrounds. The present study seeks to evaluate the degree to which important career-related variables (e.g., interest congruence, decent work) account for differences in subjective well-being (SWB) and job performance (e.g., occupational citizenship behavior [OCB], task performance) for a sample of adults from lower social class backgrounds. A novel approach to evaluating the objective indicators of social class for individual study participants was implemented to collect a sample of 365 participants, 105 of which were included in analysis. A path analysis was conducted …

Assessing Threats To Plant Populations: Linking Pollinator Differences To Patterns Of Plant Fitness And Population Genetics, Rieka Yu

Dissertations

Land use change is a major driver of biodiversity loss and consequently has led to the loss of genetic diversity in many plant populations due to declines in population sizes and an increase in spatial isolation. However, not all plant populations respond similarly to land-use change, suggesting there are additional mechanisms mediating plant population genetic patterns. Here, I examine the role of pollinators as this mediating factor. In Chapter 1 I conducted a meta-analysis to investigate how different types of pollinators drive changes in gene flow for plant populations in disturbed habitats, finding that different types of pollinators mediate different …