Digital Commons Network^™

Forceful Functors: A Categorical Approach To Constraint Monitoring In Machine Learning Models, Jonathan Wirkkala

Theses and Dissertations

Often times in machine learning there are several heuristic choices that one makes during model selection, training, and validation. These choices include the type of training used, the width and depth of the model, type activation function and many more. These choices are general rules of thumb and best practices when creating a machine learning algorithm to achieve acceptable results. For example, in the case of image processing, this may mean determining whether or not a given image contains a tumor. Decisions made during the design process create several variations of machine learning algorithms, all with various properties with pros …

Life Is Just A Classroom: Student Perceptions Of Courses Incorporating Popular Culture, Virginia Clinton-Lisell

Education, Health & Behavior Studies Faculty Publications

Some faculty design and teach college courses that incorporate popular culture, presumably to engage and spark interest in students. The purpose of this study is to examine student perceptions of courses that incorporate popular culture. College students (N = 464) were randomly assigned to read a course description and learning objectives that incorporated popular culture in general, the specific popular cultural celebrity Taylor Swift, or no mention of popular culture (control). Incorporating popular culture generally or specific to Taylor Swift had no overall effects on topic interest in the course or likelihood to enroll. However, students with greater interest in …

Practical Necromancy For Beginners: A Short Incomplete Opinionated Introduction To Artificial Intelligence For Archaeology And History Students, Shawn Graham

Digital Press Books

Many feel bewildered and quietly embarrassed that they don’t know more about how AI technology works, where it came from, or even how to get started. Start here.

Practical Necromancy represents Shawn Graham’s vision for how we should treat large language model (LLM) artificial intelligence applications. Graham advocates approaching these technologies as a necromancer. In antiquity, the figure of the necromancer lay outside the boundaries of official religion, talking not with gods but with the mournful echoes of ghosts. Practical Necromancy explores ways of surfacing the ghosts that lurk in AI technology. Graham suggests that the most useful thing we …

Stem Professors’ Motivation To Engage In A College Teaching Certificate, Justin Craig Alexander

Theses and Dissertations

Despite an expanded focus on educating students in STEM disciplines, nearly half of U.S. college students who enroll in these degree programs fail to graduate (Hamm et al., 2020, p. 623). Critics sometimes blame pedagogically untrained faculty (e.g., Kahn, 2022). This Dissertation in Practice (DiP) focused on STEM university faculty's motivation for teaching and whether professors are motivated to enroll in pedagogy courses. Via the lens of self-determination theory (SDT), this DiP examined to what extent STEM faculty at a major research university in the upper Midwest could devote additional time to pedagogy by enrolling in a college teaching graduate …

Concept Application Of Active Magnetic Bearing Technology For Offshore Horizontal Axis Wind Turbines, Isaac Ansah

Theses and Dissertations

Wind energy continues to lead the global transition to renewable power, driven by its minimal environmental impact and high scalability. Offshore wind farms benefit from stronger and consistent wind resources. However, these advantages are tempered by challenges related to installation, maintenance, and drivetrain reliability. Conventional bearings, which support the drivetrain system, are prone to wear related failures due to lubrication breakdown and mechanical fatigue from continuous loading. This study explores the integration of Active Magnetic Bearings as an alternative to conventional bearings in offshore Horizontal Axis Wind Turbines. Using advanced engineering simulation tools, the main driveshaft of a 130 MW …

Computational Prediction Of Hemolysis In Laminar Non-Newtonian Fluid, Nasim Gholizadeh

Theses and Dissertations

Hemolysis, the rupture of red blood cells (RBCs), is a critical concern in blood-circulating devices, requiring accurate predictions to ensure patient safety. This study investigates the sensitivity of hemolysis predictions to variations in viscosity models and hemolysis coefficients under complex flow conditions. Computational Fluid Dynamics (CFD) simulations were conducted using Ansys Fluent and OpenFoam on identical meshes with the FDA benchmark nozzle model. Under laminar flow conditions, CFD frameworks accurately predicted global variables, but variations in derived quantities, such as strain rate and vorticity, emerged due to differences in numerical solvers and gradient evaluation methods. These variations affected predictions of …

Laboratory Application Of An Aircraft Particle Imaging Probe To Characterize Levitated Ice Crystals And Their Aerodynamic Drag, Cheyenne Phoenix Harrison

Theses and Dissertations

Ice crystals in the upper atmosphere range in size from a few nanometers to a few millimeters, creating potential damage to vehicles traveling at hypersonic speeds; this problem has not yet been investigated with controlled laboratory techniques. This thesis investigates ice crystal impacts on high-speed flight vehicles and their aerodynamics by exploring a new method to combine ice crystal and shock wave experimental apparatuses to achieve experiments of observing ice crystals and shock waves interacting. The objectives of this research are: (1) to consistently produce levitated ice crystals in a setup that can feasibly release the ice crystals into a …

Energy Systems Optimization Techniques In The Oil And Gas Industry With Special Attention On Oil Field Reciprocating Compressors, Sean Jainarine

Theses and Dissertations

The oil and natural gas exploration and production industry is undergoing rapid growth, resulting in an increased number of operational wells and heightened potential for air emissions from oil and natural gas sources. Within production sites, compressors play a pivotal role and are often regarded as the "heart of a manufacturing plant" in the oil and gas sector. These crucial devices are designed to compress air or other gases to pressures higher than atmospheric pressure. Gas compression is typically achieved using devices with rotating blades or cylinders featuring reciprocating compressors while are essential for operations demanding high-pressures in small packages. …

Doctoral Student Mentoring: A Quantitative Analysis Of Faculty And Student Perceptions And Expectations, Laura Margaret Look

Theses and Dissertations

Doctoral student success is heavily influenced by the quality of mentoring and advising relationships with graduate faculty, yet doctoral student completion rates remain at a low rate of around 50%. The purpose of this quantitative study was to examine the mentoring relationships of doctoral students by surveying doctoral students and graduate faculty who mentor graduate students to identify their expectations for the mentor and mentee in the mentoring relationship. Data were collected from 155 students and 68 faculty in the spring 2024 semester at the University of North Dakota, a Midwest R2 institution. Nonparametric statistical analysis revealed several misalignments between …

Extreme Environment Tribological Studies Of Multifunctional Materials, Matt Malusky

Theses and Dissertations

This research examines polymer wear behaviors across polyether-etherketone (PEEK) and polylactic acid (PLA) composites in varying environmental conditions. Tribological investigations of ceramic and intermetallic coatings are explored in the context of material selection for lunar operation. In the first study, PEEK composites incorporating ternary nanolaminate ceramics, termed MAB and MAX phases, were tested in varying temperature environments above and below their expected glass transition temperatures to evaluate their tribological performance in comparison to a non-reinforced PEEK substrate. Results showed that under ambient conditions, both MoAlB (MAB phase) and Cr2AlC (MAX phase) ceramics stabilize the friction coefficient compared to pure PEEK, …

Chemical Looping As An Enabling Technology For Low-Carbon Energy Production, Junior Neguieh Domkam Nasah

Theses and Dissertations

Growth in global gross domestic product has historically been tied with high-carbon energy sources. Development of new low-carbon energy technologies is thus key to achieving a de-coupling of energy demand from economic growth. This dissertation evaluates the technical feasibility of a small-scale low-carbon solution referred to as Combined Hydrogen, Heat and Power (CH2P), a synthesis gas to hydrogen chemical looping process. The CH2P process is based on the steam-iron process and adopts multiple batch reactors to convert syngas in a two-step approach. First, the syngas is partially oxidized by reducing Magnetite (Fe3O4) to Wüstite (FeO) followed by complete oxidation in …

Student Participation In Informal Resolution: Examination Of Impact Factors On Recidivism And Student Perceptions Of Institutional Care And Fairness, Linnea Rose Nelson

Theses and Dissertations

This exploratory case study, conducted at the University of North Dakota (UND), examined factors influencing recidivism and student perceptions of institutional care and fairness among participants in the piloted Informal Resolution (IR) option. A restorative justice (RJ)-informed alternative to the traditional student conduct process, the IR is offered to students charged with first-time, low-level violations of UND’s code of conduct. This study aimed not only to evaluate the new process but also to respond to recent calls from scholars and practitioners for more extensive research on the intersection of RJ and student conduct outcomes. Sherman’s (1993) defiance theory provided the …

From Theory To Practice: Addressing The Operational Challenges Of School Principals, Darin Murry Scherr

Theses and Dissertations

School principals play a crucial role in the effectiveness of educational institutions, yet many enter leadership positions lacking adequate preparation for operational responsibilities. This Dissertation in Practice examines the challenges principals face in managing financial, staffing, and facility operations and the impact of these challenges on principal retention. Using a qualitative multiple-case study approach, the research investigates the experiences of new and veteran principals within Bismarck Public Schools to identify gaps in their operational preparedness.Findings highlight five key themes: (1) gaps in financial and budgetary training, (2) the role of mentorship and support systems, (3) balancing instructional leadership with operational …

Synthesis And Characterization Of Additive Manufactured Functional Composites For Biomedical Applications, Alexander Thorne

Theses and Dissertations

This dissertation investigates the synthesis and characterization of 3D printed polymer composites, with engineered porosity and both natural and synthetic additives, using fused deposition modeling (FDM) and selective laser sintering (SLS) for potential biomedical applications. The structural, mechanical, tribological, and surface behavior of these composites were evaluated with respect to their suitability for orthopedic load-bearing implants and scaffolds. In the first phase, PEEK-based composites reinforced with 10 or 20 wt% carbon fibers or 20 wt% E-glass fibers were fabricated using FDM with varying infill densities of 30-100% to introduce porosity. Results revealed that loading additives, infill densities, and porosity play …

Advancing Human-Computer Interaction Systems Through Explainable And Secure Ai Integration, Ifiok Udoidiok

Theses and Dissertations

As artificial intelligence (AI) systems increasingly shape how humans interact with digital environments, the need for transparency, security, and robustness in intelligent decision making has become critical. This thesis explores how explainable and secure AI techniques can be integrated into modern human-computer interaction (HCI) systems to enhance trust, resilience, and alignment with human operators.

We present three related studies, each addressing a distinct challenge in the design of human-centered AI. First, we apply XAI methods, specifically Local Interpretable Model-Agnostic Explanations (LIME), to deep learning (DL) based CAPTCHA solvers. By interpreting model attention patterns, we uncover exploitable weaknesses in text CAPTCHA …

Targeted Coaching In The Detroit Promise Path: A Thematic Network Analysis Of Current Challenges And Opportunities For Student Success, Maryse Danielle Wilson

Theses and Dissertations

The Detroit Promise Program is one of the many college promise programs operating within the United States that offers full college tuition coverage to students within the city who meet certain residential criteria. Detroit’s population has one of the highest proportions of Black and first-generation students and the lowest average socioeconomic class in the country. From the time of the Promise Program’s launch until now it has seen minor improvements in college degree competition rates, but this rate is still low compared to the national average. The Detroit Promise Path, which is an off branch of the Detroit Promise Program, …

Comparative Analysis Of Lstm-Based And Traditional Hydrologic Models For River Discharge Prediction: A Case Study Of The Goose River, Adewale Ajao

Theses and Dissertations

Streamflow predictions are important in planning water resources and effective hydrological management. Physically based models such as the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) have been used in the past for this purpose. Still, the use of machine learning models such as Long Short-Term Memory (LSTM) has been proven to complement the use of traditional models. This study compares the reliability performances of HEC-HMS and LSTM models to predict the streamflow of Goose River Watershed in North Dakota. The objective of the research is to perform a comprehensive comparative analysis between the performance of HEC-HMS and LSTM models to predict …

Domain Adapted Signal Classification For Simulated And Real-World Signals, Mohammad Ali

Theses and Dissertations

Signal classification models based on deep neural networks are trained on a set of data either simulated or over-the-air that are restricted to specific channel environments, varying distortion conditions such as SNR offsets. The consequence are models that unexpectedly do not do well in scenarios when the feature distribution between domains are too large such as when simulated models are deployed in real world environments. In this regard, we propose signal classification framework leveraging Domain-Adversarial Neural Networks to address SNR variability for simulated data Unsupervised Domain Adaptation frameworks for simulated to real world signals. Our first approach employs domain adversarial …

The Influence Of Active Galactic Nuclei (Agn) Feedback On Star Formation In Spiral Galaxies, Moreom Akter

Theses and Dissertations

We investigate the influence of Active Galactic Nuclei (AGN) feedback on star formation in spiral galaxies by analyzing a sample of 324 red and 273 blue spiral galaxies from 115 low-redshift galaxy clusters. The multi-wavelength dataset combines optical emission line data from the Sloan Digital Sky Survey (SDSS), X-ray luminosity from the Chandra X-ray & XMM-Newton observatories, and ultraviolet (UV) and infrared (IR) measurements from GALEX and WISE. Using diagnostic emission line ratios, we constructed Baldwin, Phillips, and Terlevich (BPT) diagrams to classify galaxies based on nuclear activity. Our analysis reveals that most of the red spirals have AGNs and …

Learning To Teach Digital Literacy: Faculty As Learners, Nicole Marie Maier Derenne

Theses and Dissertations

Rapid developments in artificial intelligence technologies and widening digital divide inequities have made digital literacy instruction an urgent priority in higher education. This qualitative, interpretive case study examined how faculty learned to teach Digital Information Literacy at an instructional development workshop facilitated by academic librarians, following a mandate to integrate digital literacy into the institution’s general education program. Using transformative learning theory as a framework, data were collected from a purposive sample of faculty, librarians, and administrators involvedin the workshop through field notes, interviews, a focus group, document reviews, and journaling, and then hermeneutically analyzed. Findings revealed that although demonstrations …

Advanced Motor Control Using Td3 Model-Free Reinforcement Learning, Muhammad Azam

Theses and Dissertations

Motor control plays a critical role in industrial automation, ensuring the precise regulation of speed, torque, and position across various applications. Traditional motor control techniques, such as open-loop, closed-loop, and feedback control, have been widely used but face limitations in handling complex and dynamic systems. Recent advancements in machine learning (ML) offer potential improvements in motor control by enabling systems to learn optimal control policies autonomously. This research investigates the integration of Reinforcement Learning (RL) with Field-Oriented Control (FOC) for the control of Permanent Magnet Synchronous Motors (PMSMs). The study aims to address a significant gap in reward function design, …

Enhancing Green Hydrogen Integration In Distributed Energy Systems, Solomon Evro

Theses and Dissertations

This study investigates strategic integration of green hydrogen into Distributed Energy Systems (DES) as a means of addressing three closely related challenges: first, uncertainties in hydrogen supply due to renewables intermittency; second, non-existence of practical, scalable modeling solutions for early-phase DES planning involving Alkaline Water Electrolyzers; and third, a lack of sufficient policy frameworks facilitating mass deployment. Existing hydrogen production models are often too complex for effective use in DES and do not relate stack number, input power, and renewable resource fluctuation. To address this limitation, the paper introduces a new probabilistic electrolyzer sizing method based on cumulative distribution function …

Belongingness And Science Identity Of Underrepresented Students In Aerospace Sciences, Bella Hettich

Theses and Dissertations

Despite efforts to support underrepresented individuals—specifically those from racial, ethnic, and gender minority groups—they continue to face unique challenges that affect their belongingness in aerospace sciences, leading to issues with retention in educational programs and subsequent professional pathways. Such hindrances to personal achievement can also impede broader organizational goals. Addressing these challenges is critical, as supporting the success of underrepresented individuals fosters diverse perspectives, which are essential for driving innovation and maximizing organizational productivity. Just as importantly, ensuring that every individual, regardless of background, has access to opportunities and the support needed to succeed fulfills an ethical obligation. Upholding the …

Hybrid Energy Storage Systems For Renewable Integration: Combining Batteries, Supercapacitors, And Flywheels, Tanwa Morohunkeji Iwayemi

Theses and Dissertations

Renewable energy integration into existing power grids is crucial for a sustainable future, but its intermittency poses technical challenges to grid stability and reliability. Hybrid Energy Storage Systems (HESS), combining lithium-ion batteries, supercapacitors, and flywheels, offer a promising solution by leveraging the complementary strengths of these technologies. This study explores optimal configurations of HESS using HOMER Pro software and a theoretical analysis approach to establish unified mathematical models for the three storages with constraints to address various operational scenarios, including normal operation, absence of renewable sources, and component failures. The proposed system integrates an Energy Management System (EMS) using a …

Thermally Induced Evolution Of The Cement Microannulus In Co2 Injection Wells, Jawad Ali Khan

Theses and Dissertations

Ensuring wellbore integrity during CO₂ injection is a critical challenge in Carbon Capture and Storage (CCS), as failures at the casing-cement and cement-formation interfaces can create potential leakage pathways. This dissertation presents a multi-scale, physics-based investigation into well integrity risks, integrating finite element analysis (FEA), thermal-mechanical-poroelastic modeling, and transient stress analysis to evaluate cement sheath stability, fracture-driven stress localization, and microannulus formation under various CCS conditions.

A key novelty of this research is the development of a fully coupled thermal-mechanical-poroelastic FEA framework using COMSOL Multiphysics, a renowned industry-standard software for multiphysics simulations. This model enables a dynamic, time-dependent assessment …

A Federated Learning Solution For Secure And Scalable Edge Computing In Distributed Environments, Muhammad Hamza Karim

Theses and Dissertations

The growing penetration of Distributed Energy Resources (DERs) into the modern power system has introduced significant challenges related to data volume and cybersecurity. Centralized approaches struggle to process the large volume of data generated by inverters or other DER-related assets securely and efficiently. This problem raise concerns about the confidentiality, integrity, availability, and accountability (CIAA) properties of DER assets. Moreover, the large deployment of Internet of Things (IoT) and edge computing devices has introduced new security vulnerabilities. Malicious actors can exploit resource-constrained edge devices for unauthorized activities and resource consumption, threatening the performance and operational capabilities of the edge infrastructure. …

The Role Of Student Loan Debt On Delayed Homeownership Among Black American College Graduates, Dedan Makongoro Kusaga

Theses and Dissertations

The growing burden of student loan debt in the United States has raised significant concerns about its broader social and economic impacts, particularly on young adults’ ability to achieve financial milestones such as homeownership. Black American college graduates are especially affected, often carrying higher loan balances and facing greater financial barriers due to historical and structural inequalities. This quantitative study examined the role of student loan debt and other factors influencing delayed homeownership among Black American college graduates, using the public-use Baccalaureate and Beyond (B&B: 2008/2018) dataset from the National Center for Education Statistics (NCES). Findings indicated student loan debt, …

Creating Equitable Employment Practices For Adjunct Faculty: Perceptions Of Academic Administrators At Public Institutions In A Great Plains State, Constance Mciver

Theses and Dissertations

Adjunct faculty are a substantial feature of the higher education classroom. Their increased prevalence has contributed to elevated concerns regarding the employment practices of these part-time faculty. While numerous published accounts of adjunct faculty experiences are available, recorded perceptions of academic administrators are less prevalent. Eighty-six academic administrators from six public universities in a Great Plains state participated in a researcher-developed survey to determine the expectations placed upon and compensation practices for adjunct faculty, as well as perceptions of the strengths and weaknesses of the adjunct system and the feasibility of providing more equitable compensation. Survey findings suggest there is …

Geothermal Sweep Efficiency Enhancement Potential Analysis Using Geological Modeling And Numerical Simulation On Unconventional Deadwood Formation, Ashraf Mohammed

Theses and Dissertations

This study investigates the potential to enhance geothermal sweep efficiency in the fractured, low-permeability Deadwood Formation using a cellulose-based biopolymer and gel treatment. A geological model was developed using well log and structural data from four wells in the Williston Basin and subsequently upscaled into a numerical reservoir simulation in CMG/STARS. Laboratory core-flooding experiments on Deadwood samples were used to calibrate gel behavior under high-temperature (160 °C) and high-salinity (17% TDS) reservoir conditions.Simulation results indicate that a short-duration gel treatment—equivalent to 0.03 pore volumes over one year—can significantly reduce channeling through high-conductivity fractures. The reduction in channeling improves thermal conformance …

Development Of A Climbing Collaborative Mobile Manipulator (C2m2) For Supporting In-Space Assembled Truss Structures, John Robert Isaac Merila

Theses and Dissertations

The Climbing Collaborative Mobile Manipulator (C2M2) is being developed as a robotic system to support truss outfitting operations. The goal of the project is to build a truss climbing robot and demonstrate gaits that allow the robot to reach any point on the structure. The demonstrated motions are compared to simulated joint data. Design and construction of the robot was completed to allow for the robot to traverse the structure and operate as a stationary manipulator while grappled to the truss. A worm gear actuator system was developed for use in three 2-DOF modules composed into the 6-DOF robot. The …