Digital Commons Network^™

Classification And Analysis Of Families Of Graphs With Focus On Nordhaus-Gaddum Bounds, Sibi Pranav Muthuprakash

Theses and Dissertations

Nordhaus-Gaddum type problems focus on bounding characteristics of graph and its complement. There are certain families of graphs which yield optimal upper bounds on various Nordhaus-Gaddum characteristics of graph. In this paper, we will talk about bounding combinatorial algebraic connectivity, normalized algebraic connectivity, the Cheeger constant, and the isoperimetric number of a graph and its complement. We will identify some optimal or near optimal families of graphs and conduct an analysis on these families that will help to bound these characteristics. We will also prove and conjecture some bounds that can help in formulating stronger bounds on these characteristics of …

Flowdb: A Complete Method For Extracting Queries From Functional Programs, Koby J. Lewis

Theses and Dissertations

Programmers working on database-backed applications frequently face trade-offs between designing maintainable software and efficient software due to the overhead of querying a database. We demonstrate FlowDB, an analysis for database-backed programs that can aid in program transformations that allow a program to be written in a maintainable style while still being performant. FlowDB employs demand-driven control flow analysis (DCFA) to produce a set of query sites that may be evaluated during the execution of a program. This set of query sites may then be used by a developer or compiler to cache needed results.

Decoding Anisotropic Porous Medium: A Synergy Of Lattice Boltzmann Modelling And Operator Learning To Predict Permeability As A Function Of Orientation, Soumya Shouvik Bhattacharjee

Open Access Theses & Dissertations

Understanding the directional properties of porous media is essential for accurately predicting flow behavior, reactive transport, and fluid-solid interactions in systems ranging from geothermal reservoirs to energy storage devices and biological tissues. Directional variations in permeability - reflecting a medium's response to flow at different angular orientations - are particularly important for complex, inherently anisotropic geometries. In this study, we employ a Lattice Boltzmann (LBM) model to calculate directional permeabilities from porous media images subjected to varying flow inlet angles. Three classes of porous media were investigated: (1) synthetic media with circular grains, serving as isotropic baselines; (2) synthetic media …

Comparison Of Finite-Amplitude Acoustic Models: Single Equation Of Motion For Potential Vs System-Level Approaches, Mohammad Javad Mohaghegh Kojidi

LSU New Orleans Theses and Dissertations

This study evaluates two finite-amplitude acoustic models, by solving the associated equations of motion (in potential form), and then compares the results with recent studies using hyperbolic system-level approaches. An implicit numerical method is employed to solve the second-order equations in one dimension. The performances of the Diaz et al. (2018) and Blackstock (1963) models in approximating the acoustic special case of the Euler system, via velocity profile plots and related metrics, are evaluated and compared. Working in the setting of the classical signaling problem with sinusoidal input, present results (using the single equation of motion approach) provide independent confirmation …

Evaluating Immersion And Agency In Ai-Assisted Live Murder Mystery Games, Seraphina C. Courtney

LSU New Orleans Theses and Dissertations

This thesis explores the impact of AI-assisted narrative generation on player immersion and agency in a live-action roleplaying (LARP) experience. A live-action murder mystery game was designed and run in two formats: a static version with GPT-4 generated characters, dialogue, and stage directions, and a dynamic version where players created their own characters and improvised freely, guided by AI-generated narrative beats, a story element that moves the plot forward [21], that provided a narrative scaffolding for the players. The dynamic version employed a distributed computer vision system that tracks the movement of key items in the play-space so their relevance …

Induced Helical Anisotropy In Permalloy Thin Films And Patterns, Md Mahmudul Hasan

LSU New Orleans Theses and Dissertations

The goal of this research was to create thin films with induced helical anisotropy and investigate magnetic properties of such films and their patterns. An alloy of 20% iron and 80% nickel (permalloy) was used because of very small magnetocrystalline anisotropy and magnetostriction. First, an unconventional method was used to deposit films with uniaxial anisotropy by sputtering the films onto silicon substrates in the presence of a uniform field of 50 Oe along the substrate plane. This resulted in magnetic atom pairs ordering along direction of the field during film growth. Shapes of hysteresis loops measured at different angles were …

Analysis Of Popular Songs In The Us Market, Michael Myers

Theses, Dissertations and Culminating Projects

In today’s digitally driven music landscape, understanding what drive’s a song’s popularity requires insight not only into its acoustic and lyrical content, but also into patterns of listener engagement across platforms. This thesis explores the predictive and descriptive dimensions of song popularity by applying supervised and unsupervised machine learning models to a multi-source dataset integrating audio features, sentiment analysis, and temporal consumption behavior. Drawing from a novel, multi-platform dataset that includes Billboard Hot 100 rankings, Spotify acoustic features and popularity scores, streaming, airplay, and sales metrics as reported on Luminate’s Music Connect, and lyrics from AZLyrics, the study investigates the …

Comparative Expression Of Cgmp-Dependent Protein Kinase G (Pkg) From Plasmodium And Toxoplasma, Tsopmo Asaah

Theses, Dissertations and Culminating Projects

Malaria and Toxoplasmosis are life threatening diseases to humans. The search for a cure and control of these diseases is still one of the major challenges of scientists worldwide. In this research we focused on two Malaria species; Plasmodium bergei² (Pb) and Plasmodium falciparum¹ (Pf) and also on Toxoplasma gondii. Part of the life cycle of these organisms is regulated by the enzyme cyclic GMP-dependent protein kinase G (PKG)⁴. This is our drug target in this research. We believe that inhibiting this enzyme will be a great step in fighting these diseases. In this research, we devised a comparative study …

How To Do Things With Little Talking Tubes: Nonideal Speech Acts In The Digital Age, Anthony Holdier

Graduate Theses and Dissertations

In this work, I develop a view about what it means to share a social or conversational context with others, as well as what is normatively entailed by doing so. Working from a broadly Austinian perspective about the moral foundations of language use and how we use words to position ourselves within social space, as well as from a generally Stalnakerian social ontology (demarcating groups by dint of aligned or overlapping sets of commitments), I present three papers demonstrating how nonidealized, ordinary language philosophy can make sense of complex, real-world phenomena. Through analyses of heretical utterances, context collapse, and chatbot …

Evaluation Of Performance Characteristics And Groundwater Contamination Risks Associated With On-Farm Swine Carcass Disposal Via Composting And Shallow Burial With Carbon, Gustavo Castro Garcia

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation evaluates the performance of three on-farm swine carcass disposal methods: whole carcass composting (WCC), ground carcass composting (GCC), and shallow burial with carbon (SBC), focusing on biosecurity factors and groundwater contamination risks. Foreign animal diseases (FADs), such as African swine fever and classical swine fever, pose severe economic and animal well-being risks if introduced to the United States. With confirmation of an FAD, swine movement will be halted, creating an urgent need for practical, biosecure, and environmentally responsible on-farm disposal strategies for swine carcasses. Nebraska, as a leading swine-producing state, exemplifies the vulnerability of high-density livestock regions to …

Developing Guidance For The Use Of Floating Treatment Wetlands In Brackish Stormwater Ponds, Clare Escamilla

All Dissertations

Stormwater ponds are commonly used as a flood control strategy, particularly in coastal developments. Many coastal stormwater ponds are impaired with high nutrient levels that can lead to algal blooms, impacting the water quality of the pond and surrounding ecosystem. Floating treatment wetlands (FTWs) are one potential strategy that can be implemented in stormwater ponds to reduce high nutrient concentrations, however limited research has been done in brackish waterbodies. To determine the suitability of using FTWs in brackish stormwater ponds this research focused on (1) coastal resident perceptions of FTWs and (2) plants that can be utilized in FTWs deployed …

Predicting Music Origin With Deep Learning, Fruzsina Ladanyi

Electronic Theses, Projects, and Dissertations

This project explores the usage of a late fusion deep learning architecture to predict the geographic origin of music. Mel-Frequency Cepstral Coefficients (MFCCs) and the language of the music sample are used as features. MFCCs were extracted from audio files to capture sound features. The language was identified using OpenAI’s Whisper model to provide additional context. A late fusion neural network architecture combining Long Short-Term Memory (LSTM) layers for sequential MFCC input and dense layers for non-sequential language features were employed to support both classification and regression tasks. The classification model achieved an accuracy of 33.03% across 56 countries or …

Fact-Checker: A Web Application For Leveraging Large Language Models For Fact-Checking Youtube Videos, Andrew R. Craig

Electronic Theses, Projects, and Dissertations

Fact-Checker is a web application that allows users to fact-check YouTube videos. It feeds YouTube’s closed captioning transcript to a large language model (LLM) to extract claims. It then uses multiple LLMs, such as Gemini, Llama, and Claude, to verify these claims. The modular design makes it easy to change to a different LLM or model if needed. The application is built using Python for access to Application Programming Interfaces (APIs) and Streamlit as the front-end framework. The utilization of Docker and Dockerfiles enables easy distribution and deployment. It enables the application to be deployed on almost any hardware platform …

Robustness Investigation, Detection, And Defense Of Deep Learning Models Against False Data Injection, Amirhossein Nazeri

All Dissertations

This dissertation addresses the critical challenge of adversarial robustness in deep learning systems, focusing on two fundamental domains: time-series prediction and object detection. As these AI systems become increasingly deployed in safety-critical applications from power grid management to autonomous vehicles their vulnerability to adversarial attacks poses significant risks to infrastructure and human safety.

The first contribution introduces a novel stealthy black-box False Data Injection (FDI) attack specifically designed for quasi-periodic time-series data. Unlike existing attacks that produce easily detectable anomalies, our method generates adversarial perturbations that preserve the underlying periodicity and statistical properties of the data, effectively bypassing traditional anomaly …

Improving Coastal Hydrodynamic Model Performance Through Parameter Sensitivity Analysis And Optimization, Sunni Siqueira Allen

LSU New Orleans Theses and Dissertations

This thesis presents a framework for parameter sensitivity analysis and optimization of coastal hydrodynamic models. The research uses the Generalized Likelihood Uncertainty Estimation (GLUE) method to quantify parameter sensitivity and identify optimal values for currents, wave height, and water level. A variance-based technique guides parameter selection when GLUE yields competing values or when observations are unavailable.

The framework is demonstrated through two case studies: Hurricane Michael (2018) and the ExCaliBur field study (2022) near Oceanside, CA. Results from Hurricane Michael show higher optimal hydrodynamic model bottom friction values near the hurricane's landfall location. The Oceanside study identifies the hydrodynamic model's …

Mechanistic And Evolutionary Insights Into A Group Of Nicotine And Hydroxynicotine Degrading Flavoenzymes, Zhiyao Zhang

Dissertations

Flavoprotein amine oxidases (FAOs) are key enzymes in various kinds of metabolic pathways, mediating redox reactions via flavin cofactors. While most FAOs function as oxidases that readily reduce oxygen to hydrogen peroxide, a few outliers of the FAO family act as dehydrogenases that suppress the reaction with oxygen. The molecular basis for this divergence in function remains poorly understood.

The work presented in this study investigates the fundamental mechanisms of how flavincontaining enzymes activate or suppress their reaction with different electron acceptors to achieve high turnover rates. The overall body of work is divided into three different sections that (1) …

Insights From Swot Data On Transboundary Upstream-Downstream Impacts In The Nile Basin, Hesham Morgan, Wenzhao Li, Ali Elgendy, Surendra Maharjan, Rejoice Thomas, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study utilizes high-resolution data from NASA's Surface Water and Ocean Topography (SWOT) mission to investigate water dynamics and upstream-downstream impacts across key reservoirs in the Nile Basin. Focusing on the Grand Ethiopian Renaissance Dam (GERD), Rosaries Dam, Merowe Dam, and the Aswan High Dam, the analysis spans 15 months (August 2023 to October 2024). By systematically selecting 30 points across each reservoir, monthly boxplots of surface water elevation were generated, revealing significant temporal and spatial variability. The results show that GERD’s filling phase led to a steady increase in water levels (peaking at ~615 meters from June to October …

Assessing Coastal Vulnerability And Climate-Driven Migration Risk In West Africa, Wenzhao Li, Surendra Maharjan, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study presents a GIS-based multi-criteria decision-making framework to assess climate-induced migration risk along the West African coast. We developed a comprehensive risk index that integrates environmental hazards such as flood frequency and socio-economic vulnerability indicators, including poverty levels, population density, and adaptive capacity. By utilizing datasets such as the Geocoded Disasters (GDIS) dataset, Social Vulnerability Index (SVI), Poverty and Adaptive Capacity Index (PACI), and the Population Exposure Index (PEI), the study identifies regions most susceptible to displacement. Results reveal that areas like Benin’s Abomey-Calavi, Cotonou, and Akpo-Misserete are especially vulnerable due to high disaster frequency, substantial population exposure, and …

Guided Modes Through The Dual Perspectives Of Geometrical Optics And Wave Equation, Mason Spears

Mathematics and Statistics Undergraduate Departmental Honors Theses

In an optical waveguide, only finitely many electric field intensity profiles travel without loss, and these are aptly named guided modes. This paper uses fundamental concepts from the two paradigms of interpreting light, geometrical and physical optics, to derive guided modes axiomatically. First, basic principles of geometrical optics are demonstrated in a slab waveguide to explain characteristics of optical waveguides such as total internal reflection and numerical aperture. Dispersion curves are assembled from the same principles and used to show that only finitely many guided modes exist for a given waveguide. Next, Maxwell’s equations are used to derive the famous …

Enabling Sustainability Transitions For Great Salt Lake: Framing Of Public Opinion, Boundary Work, And Policy, Anna Mcentire

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation explores how people think about, talk about, and take action to save Great Salt Lake, which reached historic low levels in 2021. Using surveys, public records, and legislative documents primarily from 2022 to 2024, the research examines public opinions, collaborative efforts, and policy changes related to the lake. The first chapter looks at what people value about the lake and what actions they want to see taken. It finds that people are very concerned and want significant efforts to stop the lake's decline. The second chapter investigates how different groups work together publicly to negotiate new understandings, create …

Enhanced Point Cloud Generation From A Novel 360° Underwater Lidar, Olagoke E. Daramola

Dissertations

This dissertation presents novel algorithms to improve the mapping capabilities of a 360-degree underwater Pulsed Laser Line Scanner LiDAR (PLLS-360°). Due to its 360° field-of-view (FOV), the PLLS-360° is a compact full-waveform omnidirectional imager suitable for seafloor mapping, underwater asset inspection, object detection, ice-sheet mapping, and construction progress monitoring. The proposed methodology includes an improved waveform fitting technique for saturated waveform recovery, detection array response correction, radiometric corrections, and fusion of LiDAR and sonar bathymetric datasets. The first part of this dissertation assesses the LiDAR’s performance and describes how the data for this unique 360° FOV architecture is processed. The …

Causalabstain: Enhancing Multilingual Llms With Causal Reasoning For Trustworthy Abstention, Yuxi Sun, Aoqi Zuo, Wei Gao, Jing Ma

Research Collection School Of Computing and Information Systems

Large Language Models (LLMs) often exhibit knowledge disparities across languages. Encouraging LLMs to abstain when faced with knowledge gaps is a promising strategy to reduce hallucinations in multilingual settings. Current abstention strategies for multilingual scenarios primarily rely on generating feedback in various languages using LLMs and performing self-reflection. However, these methods can be adversely impacted by inaccuracies and biases in the generated feedback. To address this, from a causal perspective, we introduce CausalAbstain, a method that helps LLMs determine whether to utilize multiple generated feedback responses and how to identify the most useful ones. Extensive experiments demonstrate that CausalAbstain effectively …

Visceral, Neural, And Immunotoxicity Of Per- And Polyfluoroalkyl Substances: A Mini Review, Pietro Martano, Samira Mahdi, Tong Zhou, Yasmin Barazandegan, Rebecca Iha, Hannah Do, Joel Burken, Paul Ki-Souk Nam, Qingbo Yang, Ruipu Mu

Chemistry Faculty Research & Creative Works

Per- and polyfluoroalkyl substances (PFASs) have gained significant attention due to their widespread distribution in the environment and potential adverse health effects. While ingestion, especially through contaminated drinking water, is considered the primary route of human exposure, recent research suggests that other pathways, such as inhalation and dermal absorption, also play a significant role. This review provides a concise overview of the toxicological impacts of both legacy and emerging PFASs, such as GenX and perfluoro butane sulfonic acid (PFBS), with a particular focus on their effects on the liver, kidneys, and immune and nervous systems, based on findings from recent …

Intersecting Realities And Evolving Landscapes: Mapping Generative Ai Within The Framework Of Digital Rhetoric, Joshua Troy Nieubuurt

English Theses & Dissertations

The increased usage of [Generative] AI technologies (GenAI) in the 21st century has called into the question the rhetorical agency of these digital things. [Gen]AI has historically been framed within a Heideggerian “readiness-to-hand” dynamic in which it has been unilaterally conceived as a tool to be used by humans. This dissertation proposes that the GenAI assemblage is capable of being a co-actor in rhetorical spaces. To provide evidence for this stance This dissertation utilizes Actor Network Theory to map the actants within a GenAI assemblage. In doing so it allows for an understanding of the stakeholders (both human and non-human) …

Analysis Of Multi Grade Deep Learning, Ronglong Fang

Mathematics & Statistics Theses & Dissertations

Multi-Grade Deep Learning (MGDL) is a training framework that incrementally builds deep neural networks. It does this by dividing the training process into multiple “grades,” where each grade sequentially trains a shallow neural network to learn the residue from the previous one, using the outputs of prior grades as input. This approach progresses from shallow to deep architectures. This dissertation offers a comprehensive theoretical and numerical analysis of the MGDL methodology.

We first demonstrate that MGDL can effectively learn target functions within the sum-composition learning format. In this context, MGDL approximates high-frequency components by composing multiple low-frequency functions. This unique …

Enhancing Non-Visual Interaction With Online User-Generated Content, Mohan Krishna Sunkara

Computer Science Theses & Dissertations

The Web has become the dominant medium for our everyday activities, including communication, business, e-commerce, news, and entertainment. Consequently, the online world is experiencing an explosion of User-Generated Content (UGC), particularly on social media platforms and online review systems. To facilitate convenient interaction with UGC, web platforms have adopted various presentation strategies that enable users to efficiently browse and contribute to the UGC. However, these user interfaces are primarily designed for sighted individuals, so they do little to assist blind users who rely predominantly on audio-based screen reader assistive technology. The extant efforts to improve web interaction for blind users …

Computational Fact-Checking With Limited Resources, Fengzhu Zeng

Dissertations and Theses Collection (Open Access)

The rapid dissemination of information through online platforms has sparked widespread concern about the propagation of misinformation. Manual fact-checking by pro- fessional fact-checkers is time-consuming and lacks scalability to address the vast volume of daily information. Consequently, computational fact-checking, driven by automated techniques in natural language processing (NLP), has garnered interest as
a potential solution. However, computational fact-checking faces critical challenges limited resources, particularly due to the issues of data scarcity and computing resource constraints. One key challenge is data scarcity, which arises from the constant generation of new information and emerging events on social media. This scarcity manifests in …

Ev Charging Management In A Real-Time Optimization Framework Considering Operational Constraints, Hilmi Cihan Güldorum, Ayşe Kübra Erenoğlu, İbrahim Şengör, Barry P. Hayes, Ozan Erdinç

Department of Computer Science Publications

The electrification of transportation plays a central role in the decarbonization of energy systems. Although electric vehicles (EVs) are expected to reduce energy related emissions, the increasing demand imposed by large scale EV adoption presents serious challenges for distribution systems (DSs), which were not originally designed to accommodate such loads. This study proposes a mixed integer quadratically constrained programming (MIQCP) framework to optimize the operation of an EV parking lot (EVPL) under DS constraints. The model compares three widely adopted objective functions: minimization of active power loss, charging cost, and uncontrolled charging impact, which is represented by minimizing the total …

Do Themes Improve Visitor Outcomes In Interpretive Programs?, Amber K. Hawes

All Theses

Thematic interpretation is widely promoted as being integral to an effective interpretive program. Some studies have suggested that thematic interpretation may enhance visitor outcomes; however, park visitor demographics have changed over the last decade, and others have suggested alternative approaches. In this study, we systematically observed live interpretive programs at 330 programs at 52 National Parks across the United States, monitored the extent and characteristics of theme usage, and collected visitor surveys immediately following each program. We used these data to determine the influence of the presence and characteristics of themes and theme questions on visitor outcomes. The results suggest …

Life Cycle Assessment Of The Cultivation Of Lettuce In A Hydroponic System Using The Nutrient Film Technique, Raquel Jordan

All Theses

Hydroponic systems are an emerging method of soilless crop cultivation typically done inside a greenhouse where nutrients are delivered dissolved in water rather than being supplied from the soil. Potential benefits of hydroponic systems include reduced irrigation requirements, higher crop yield per area, and the ability to grow crops year-round in nontraditional areas such as urban settings, cold climates, and sites with contaminated soil. However, hydroponic systems tend to have high energy requirements for lighting and climate control, which can yield significant environmental impacts. To explore the environmental impacts of cultivating lettuce in a nutrient film technique (NFT) hydroponic system, …