Physical Sciences and Mathematics Commons^™

Optimizing Ai With Advanced Data Structuring: A Comparative Analysis Of K-Means And Gmm Clustering Techniques, Amir Alipour Yengejeh

Data Science and Data Mining

This study presents a detailed comparison of Kmeans and Gaussian Mixture Model (GMM) clustering algorithms, illustrating their unique capabilities and limitations across various synthetic datasets. By utilizing metrics such as the Adjusted Rand Index (ARI) and Normalized Mutual Information (NMI), the research provides nuanced insights into how these algorithms handle datasets with varying structures and complexities. For instance, while both K-means and GMM show robust performance on well-separated clusters, GMM demonstrates a distinct advantage in scenarios with overlapping clusters or unbalanced data distributions. Conversely, K-means excels in identifying clear, distinct groupings, highlighting its utility in simpler clustering contexts. This study …

Machine Learning Approaches For Cyberbullying Detection, Roland Fiagbe

Data Science and Data Mining

Cyberbullying refers to the act of bullying using electronic means and the internet. In recent years, this act has been identifed to be a major problem among young people and even adults. It can negatively impact one’s emotions and lead to adverse outcomes like depression, anxiety, harassment, and suicide, among others. This has led to the need to employ machine learning techniques to automatically detect cyberbullying and prevent them on various social media platforms. In this study, we want to analyze the combination of some Natural Language Processing (NLP) algorithms (such as Bag-of-Words and TFIDF) with some popular machine learning …

Xgboost Hyperberd Model Using Steam Platform, Yuh-Haur Chen

Data Science and Data Mining

This project investigates game pricing strategies in the Steam market using an XGBoost model, drawing motivation from Professor Xie's lecture, and presenting findings through a density plot that delineates two primary pricing strategies. A free-to-play approach, indicated by a significant hot spot, is adopted by developers focusing on post-purchase revenues through DLC, aesthetic purchases, and in-game transactions. This sailing strategy includes community-centric developers aiming to distribute their games for player engagement rather than profit.

The project illustrates the effectiveness of advanced modeling techniques in handling complex datasets, with significant predictive accuracy reflected by a reduced MSE from 0.3472 to 0.1397. …

Predicting Road Accident Injury Severity For Drivers In Automobile Crashes In United States Using Machine Learning Models And Ai, Emil Agbemade, Benedict Kongyir

Data Science and Data Mining

This study analyzes data from the National Highway Trafc Safety Administration’s 2021 Crash Report Sampling System to identify key factors contributing to the severity of injuries in car accidents. By utilizing various machine learning algorithms and cross-validation techniques, we assessed metrics such as accuracy, sensitivity, precision, specifcity, and the area under the curve (AUC) to evaluate the efectiveness of predictive models. All data preprocessing and model building was done using KNIME Analytical software [9]. Our fndings reveal signifcant correlations between certain variables such as airbag injection, weather conditions, intoxication, vehicle state, driver distractions, and injury severity. These insights underscore the …

Dynamics And Inverse Problems For Nonlinear Schrödinger Equations, Christopher Hogan

Doctoral Dissertations

"The cubic nonlinear Schrödinger equation (NLS) is a model of interest in the study of physical problems including nonlinear optics and Bose-Einstein condensates. Of particular interest is the study of cubic NLS with inhomogeneities such as localizations of the nonlinearity or terms introducing potential barriers. We first address some preliminaries and techniques useful in the study of the cubic NLS and its variations. We then consider the cubic NLS with a localized nonlinearity in dimensions d ≥ 2. We show that solutions with data given by small-amplitude wave packets accrue a nonlinear phase that determines the X-ray transform of the …

High-Resolution Spectroscopy Of Interstellar Lines And Comets, Chemeda Tadese Ejeta

Doctoral Dissertations

"The study of interstellar molecules such as CO is crucial because interstellar ices in the core of a pre-solar molecular cloud provide the starting point for volatile evolution in the protoplanetary disk. A record of the initial volatile composition of the protoplanetary disk can be obtained from the study of the chemical composition of cometary nuclei. Because of their long residence in the Oort cloud and infrequent passage through the inner solar system, long-period comets are one of the most primitive bodies in our solar system that can tell us about the composition of the early solar system. High-resolution infrared …

Community Science And Coyote Stories: Capturing And Communicating Nature's Non-Material Values For Use In Decision-Making, Joshua Wright Morse

Graduate College Dissertations and Theses

The reasons and ways that nature matters underlie every part of environmental decision-making. Yet, there are disparities in how different kinds of benefits from and values about nature are represented in policy and practice. This dissertation explores how decision-makers and community members value nature broadly and also in the context of a specific human-wildlife interaction in Vermont, United States.

In my first chapter, I conduct semi-structured interviews with environmental sector practitioners in Vermont to learn about their awareness of non-material values from nature. I find that practitioners talk readily about both material and non-material ecosystem services as well as multiple …

Analysis Of Ultra-Wideband Voltage Pulse Propagation On Dispersive Absorptive Transmission Lines, Katherine Aho

Graduate College Dissertations and Theses

Electromagnetic transient waves are pulsed events that occur when there is an abruptchange in the typical steady-state conditions on a transmission line. Digital pulses on integrated circuits and a lightning strike on overhead power lines are some examples of transient voltage pulses. Although transients occur within a very short time duration, they can propagate over long distances; much farther than a slowly-varying envelope signal can propagate. Lingering effects of transients can be damaging to electrical equipment if they are not properly mitigated. Despite the negative effects of transients, certain designed transient pulses may be used to an advantage in remote …

Escape The Planet: Revolutionizing Game Design With Novel Oop Techniques, Qusai Kamal Fannoun

All Graduate Theses, Dissertations, and Other Capstone Projects

Mobile devices are continuously evolving and greater computing power and graphics capabilities are being introduced every year. As a result, there is an increasing demand for challenging and engaging mobile games that leverage these advanced features. This project explores best design practices using the development of Escape the Planet, which is an intricate maze game for mobile devices in which players navigate using a spaceship that is trapped in a hostile planet’s maze while avoiding obstacles and enemy attacks. The goal is to safely guide the spaceship out of the maze without colliding into walls or taking bullets from defensive …

Intelligent Traffic Management Systems, Mohammad Mazhar

All Graduate Theses, Dissertations, and Other Capstone Projects

With the increase in population and in particular urban population. The traffic and travel times in between cities and inside cities has increased due to more and more people using private means of transportation. Due to this need arose for tackling the increase in traffic by managing it using various means. For this we look towards The Intelligent Traffic Management System (ITMS). ITMS is an AI-powered solution designed to optimize traffic flow, reduce congestion, and improve overall road safety. The system will monitor real-time traffic data using a combination of cameras and sensors, identify traffic jams, and send alerts to …

Growing Up Sustainable? Politics Of Race And Youth In Urbanplan, Copenhagen, Max Ritts, Rebecca Rutt

Geography

This paper considers how racialized youth in Denmark negotiate sustainability amid contexts marked by intersecting forms of economic restructuring, progressive neoliberalism, white ethno-nationalism, and green urban planning. Urbanplan is a low-income, notoriously “troubled” Copenhagen neighborhood where we conducted fieldwork for 7 months (2019-2020) with fifteen male youth, aged 17-21. Using ethnography, policy reviews, and interviews with city social workers, we explore how intimate experiences of nature, group-identity, and place attachment here relate to and depart from the structural forces actively reshaping the neighborhood. Our analysis combines Cindi Katz's intersectional political economy approach with recent work on green gentrification, Critical Utopian …

Fault-Tolerant Consensus In Anonymous Dynamic Network, Qinzi Zhang, Lewis Tseng

Computer Science

This paper studies the feasibility of reaching consensus in an anonymous dynamic network. In our model, n anonymous nodes proceed in synchronous rounds. We adopt a hybrid fault model in which up to f nodes may suffer crash or Byzantine faults, and the dynamic message adversary chooses a communication graph for each round. We introduce a stability property of the dynamic network - (T, D)-dynaDegree for T ≥ 1 and n - 1 ≥ D ≥1 - which requires that for every T consecutive rounds, any fault-free node must have incoming directed links from at least D distinct neighbors. These …

Farey Recursion And Hyperbolic Dehn Filling, Jose Ebenezer Martinez

Graduate Student Theses, Dissertations, & Professional Papers

In this work, we present a solution to William Thurston's edge gluing equations for Dehn fillings of hyperbolic 3-manifolds. This is done for triangulations that involve the layered solid torus. Our approach uses Farey recursive functions, and we present a Farey recursive function that provides a solution to the gluing equations for any hyperbolic Dehn filling admitting a triangulation by the layered solid torus. We provide examples that demonstrate our solution for multiple 3-manifolds, and study the roots of the corresponding Farey recursive polynomials. As an additional application of our solution, we provide a formula for the complex length of …

Mathematical Modeling Of Phage-Bacteria Population Dynamics, John Lawrence D. Palacios

Theses and Dissertations

Bacteriophages are viruses that infect and replicate within bacteria. Lytic phages cause the bacterial cell to burst, killing the bacteria. These types of phages can be used to treat patients with antibiotic-resistant bacterial infections. As a step in developing successful treatment protocols, we aim to understand the population dynamics of phages and bacteria using an in vitro model. We model the dynamics using the Campbell model, which consists of a delay differential equation (DDE), as a base model. We extended the model by including the emergence of phage resistance. We then compared the DDE model with a parallel ordinary differential …

Pharmacology Of Veratrum Californicum Alkaloids As Hedgehog Pathway Antagonists, Madison L. Dirks, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Veratrum californicum contains steroidal alkaloids that function as inhibitors of hedgehog (Hh) signaling, a pathway involved in the growth and differentiation of cells and normal tissue development. This same Hh pathway is abnormally active for cell proliferation in more than 20 types of cancer. In this current study, alkaloids have been extracted from the root and rhizome of V. californicum, followed by their separation into five fractions using high performance liquid chromatography. Mass spectrometry was used to identify the presence of twenty-five alkaloids, nine more than are commonly cited in literature reports, and the Bruker Compass Data Analysis software …

Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb

Faculty Publications: BCES

Plasmids are mobile genetic elements known to carry secondary metabolic genes that affect the fitness and survival of microbes in the environment. Well-studied cases of plasmidencoded secondary metabolic genes in marine habitats include toxin/antitoxin and antibiotic biosynthesis/resistance genes. Here, we examine metagenome-assembled genomes (MAGs) from the permanently-stratified water column of the Cariaco Basin for integrated plasmids that encode biosynthetic gene clusters of secondary metabolites (smBGCs). We identify 16 plasmid-borne smBGCs in MAGs associated primarily with Planctomycetota and Pseudomonadota that encode terpenesynthesizing genes, and genes for production of ribosomal and non-ribosomal peptides. These identified genes encode for secondary metabolites that are …

Synthesis And Characterization Of Quantum Materials, Yunsheng Qiu

Doctoral Dissertations

"In this study, attempts were made to grow quantum materials that have recently undergone a profound change of perspective. These materials are involved in intricate macroscopic properties rooted in the subtle nature of quantum physics. To explore our understanding of quantum materials, this study includes three projects: Magnetic Topological Insulators, Topological Superconductors, and high-temperature superconductors.

A Cr-doped Sb₂Te₃ is added to the category for the magnetic topological insulators project. Their transport properties are studied, and the origin of ferromagnetism is studied. Anomalous Hall effect is observed in the Hall measurements, and serval factors (cooling rate, dopant deficiency) …

Bootstrap Regression For Investigating Macroeconomics Factors Affecting Usa Home Prices, Benedict Kongyir, Emil Agbemade

Data Science and Data Mining

This study investigates the impact of macroeconomic indicators on US home prices, underscoring the importance of understanding these dynamics due to their signifcant socioeconomic consequences. Utilizing a dataset from Kaggle, originally collected by FRED, the research examines variables like the Consumer Price Index, Population, Unemployment, GDP, Stock Prices, Income, and Mortgage Rate to discern their efect on housing market fuctuations. The analysis identifes multicollinearity among predictors, necessitating a shift from traditional multiple linear regression to a more robust bootstrap regression method due to violations of parametric assumptions. Key fndings reveal that Real Disposable Income is a signifcant predictor of home …

Solutions To The Kaluza-Klein Field Equations, Abel Eshete

All Graduate Theses, Dissertations, and Other Capstone Projects

This Alternate Paper Plan explores Kaluza-Klein theory, a multidimensional framework designed to unify Einstein’s gravitational field theory and Maxwell’s electromagnetic field theory. The objectives of this research can be summarized in two key areas: The first objective is to present a comprehensive introduction to the compactified Kaluza-Klein theory. The second aim involves the application of differential geometry, specifically E ́lie Cartan’s tetrad formalism, to derive exact solutions in two distinct scenarios: a. A Levi-Civita spacetime, b. A general spherical system. Furthermore, Lagrangian and Hamiltonian formalism are utilized to define stability conditions and describe gravitational lensing and Precession of Perihelion within …

Impact Of Solar Radiation On Perchlorate Formation In The Atmosphere: Evidence From Ice Core Measurements, Bishnu Kunwar

Electronic Theses and Dissertations

Perchlorate, which derives from both anthropogenic and natural sources in the current environment, poses a substantial health hazard to humans as it competes with iodine uptake in the thyroid gland. Consequently, there has been considerable concern about minimizing human exposure to environmental perchlorate by restricting its release from man-made sources. However, the absence of a clear understanding regarding the respective contributions of man-made and natural sources has hindered widespread regulation efforts. A 300-year (1700–2007) Summit, Greenland ice core record from a previous study showed relatively stable perchlorate concentrations in Greenland snow prior to 1980, with some elevated perchlorate levels associated …

Species Distribution Modeling Of Aquilegia Brevistyla (Ranunculaceae): A Critically Imperiled Black Hills Disjunct Species, Eric Daniel Puetz

Electronic Theses and Dissertations

Unchecked human activity is contributing to rising levels of greenhouse gas emissions, changes in land use, altered disturbance/fire regimes, spread of invasive species, and loss of biological diversity and related breakdown of ecosystem services. Additionally, climatic shifts may lead to phenological mismatches between species and their environments if these changes outpace a species’ ability to adapt or migrate to a more suitable habitat. Isolated mountain populations are particularly threatened by unpredictable climatic conditions, as they may have limited migration corridors and often lower levels of genetic diversity to move or adapt, respectively. As these negative feedbacks compound on the landscape, …

The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson

Electronic Theses and Dissertations

Long-term and intensified agricultural land management has resulted in increased rates of soil erosion and has altered much of the carbon cycle at regional and global scales. Anthropogenic degradation of soil resources is a barrier to sustainable production, soil functioning, and ecosystem services. It is difficult to quantify the scope of pedogenic changes due to the lack of legacy data and short temporal scales. This study utilized decades to century-old soil information to quantify historical soil erosion losses and changes in soil carbon pools of eastern South Dakota soils. The results show that soils in the region have been significantly …

The Effect Of Social Determinants Of Health On End-Stage Kidney Disease Mortality Across Diverse Adult Populations: Systematic Review And Meta-Analysis, Prince Agyapong

Electronic Theses and Dissertations

Background: This systematic review and meta-analysis aimed to examine the influence of social determinants of health (SDOH) on End-Stage Kidney Disease (ESKD) mortality among diverse racial populations. Given the high morbidity and mortality associated with ESKD, understanding the impact of various SDOH factors across different racial groups is crucial for improving patient outcomes.
Methods: A comprehensive literature search was conducted to identify studies reporting on the relationship between SDOH and ESKD mortality using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) format. Citations were collated in EndNote 21 and screened in Covidence by two independent reviewers, with inter-rater …

Improving Stream Connectivity In South Dakota, Colton Rainier Curtis

Electronic Theses and Dissertations

Stream connectivity is crucial for fish movement and genetic diversity in fragmented landscapes. Road-crossings often act as barriers, disrupting hydrology and isolating fish populations. The Southeast Aquatic Resources Partnership (SARP) has developed rapid road-crossing assessment protocols and tools to prioritize restoration projects. However, managers lack tools for planning, directing, and initiating roadcrossing assessments. Managers also require modeling approaches to effectively identify and monitor road-crossings across dynamic stream networks. Presented here is a case study offering a roadmap for effective implementation of collaborative road-crossing assessments and prioritization of remediation projects, alongside an exploration of predictive modeling approaches to identify problematic crossings …

Refining The Inverse Lipschitz Constant For Injective Relu Networks, Cole Rausch

Electronic Theses and Dissertations

In this thesis, we study the Inverse Lipschitz Constant (ILC) of injective ReLU layers. We study the tightness of the ILC lower bound established in Puthawala et al. Our approach has three components. First, we find that the conditions for injectivity on lines yield a weaker condition than the general condition given in Puthawala et al. Second, we perform numerical experiments to judge the tightness of the existing ILC lower bound and find that bound is overly conservative. Third, we identify the source of the potential slack in the proof of the existing ILC bound, and perform further numerical experiments …

Development Of Low Threshold Germanium Detectors For The Search Of Low Mass Dark Matter, Pramod Acharya

Dissertations and Theses

This dissertation explores using high-purity germanium (Ge) crystals for low-mass dark matter (DM) detection, focusing on enhancing crystal quality and identifying key crystal growth parameters. The study assesses the electrical properties of refined Ge materials through Hall Effect measurements and uses machine learning to predict impurity profiles, achieving levels conducive to high-resolution DM detectors. Utilizing a planar Ge detector fabricated at Texas A$\&$M and operated at cryogenic temperatures at the University of Minnesota, the study reveals time-dependent internal charge amplification through impact ionization. Research on charge transport dynamics in a cryogenic p-type Ge detector uncovers evolving charge dynamics and cluster …

Incivility In Open Source Projects: A Comprehensive Annotated Dataset Of Locked Github Issue Threads, Ramtin Ehsani, Mia Mohammad Imran, Robert Zita, Kostadin Damevski, Preetha Chatterjee

Computer Science Faculty Research & Creative Works

In the dynamic landscape of open-source software (OSS) development, understanding and addressing incivility within issue discussions is crucial for fostering healthy and productive collaborations. This paper presents a curated dataset of 404 locked GitHub issue discussion threads and 5961 individual comments, collected from 213 OSS projects. We annotated the comments with various categories of incivility using Tone Bearing Discussion Features (TBDFs), and, for each issue thread, we annotated the triggers, targets, and consequences of incivility. We observed that Bitter frustration, Impatience, and Mocking are the most prevalent TBDFs exhibited in our dataset. The most common triggers, targets, and consequences of …

Assessing The Utility Of Breast Cancer Polygenic Risk Scores And Association With Clinical Factors In A Population Of Breast Cancer Patients, John L. Slunecka

Dissertations and Theses

INTRODUCTION: Breast cancer (BC) is the most common cancer among women and is classified as a complex disease. Advances in population genomics have led to the development of polygenic risk scores (PRSs) with the potential to enhance current risk models, but replication is often limited. OBJECTIVE: We sought to assess the predictive capabilities of two high-powered BC PRSs in a sample population selected for breast cancer. In addition, the capacity of the PRSs to predict clinical variables that could improve BC screening and treatments was explored. METHODS: Two published PRS algorithms (313 vs 3820) were used to score female subjects …

Facilitating Mathematics And Computer Science Connections: A Cross-Curricular Approach, Kimberly E. Beck, Jessica F. Shumway, Umar Shehzad, Jody Clarke-Midura, Mimi Recker

Publications

In the United States, school curricula are often created and taught with distinct boundaries between disciplines. This division between curricular areas may serve as a hindrance to students' long-term learning and their ability to generalize. In contrast, cross-curricular pedagogy provides a way for students to think beyond the classroom walls and make important connections across disciplines. The purpose of this paper is a theoretical reflection on our use of Expansive Framing in our design of lessons across learning environments within the school. We provide a narrative account of our early work in using this theoretical framework to co-plan and enact …

A Memory Efficient Deep Recurrent Q-Learning Approach For Autonomous Wildfire Surveillance, Jeremy A. Cantor

UNF Graduate Theses and Dissertations

Previous literature demonstrates that autonomous UAVs (unmanned aerial vehicles) have the po- tential to be utilized for wildfire surveillance. This advanced technology empowers firefighters by providing them with critical information, thereby facilitating more informed decision-making processes. This thesis applies deep Q-learning techniques to the problem of control policy design under the objective that the UAVs collectively identify the maximum number of locations that are under fire, assuming the UAVs can share their observations. The prohibitively large state space underlying the control policy motivates a neural network approximation, but prior work used only convolutional layers to extract spatial fire information from …