Digital Commons Network^™

Evaluating Planting Methods For Native Seed Production And Exploring Granivory In The Northern Great Plains, Allison Dollen

Electronic Theses and Dissertations

Temperate grasslands have faced immense losses due to land use change in the last 150 years and less than half of the overall grasslands that once covered North America remain today. A portion of historic and remaining U.S. grasslands are located within the northern Great Plains (NGP) region which is home to over 1,600 species of native plants and provides many ecosystem services and economic benefits. Initiatives to restore grasslands and their ecosystem services are currently underway, but barriers such as limited native seed supply and granivory hinder restoration efforts. My first chapter addresses knowledge gaps in planting methods for …

Integration Of Ders Volt-Var Dynamic Constraint Into Time-Coupled Optimal Power Flow For System Stability, Shadrack T. Asiedu

Electronic Theses and Dissertations

The transition toward power systems with higher levels of inverter-based generation requires operating models that account for the dynamic support available from distribution-connected resources. Although inverter-based DERs can provide fast reactive-power support through functions such as Volt–VAR control, conventional optimal power flow models generally represent these resources as static power injections. In addition, transmission-level dispatch commonly represents the downstream distribution system as an aggregated load and does not explicitly consider the voltage at the point of common coupling. Consequently, an OPF solution may satisfy the transmission-bus voltage constraints while producing an operating point at which the downstream DERs do not …

Modeling Heterogeneous Trajectories Of Chronic Kidney Disease Progression With Finite Mixture Models Using The All Of Us Dataset, Yahaya Mumuni Musah

Electronic Theses and Dissertations

Background: Chronic kidney disease (CKD) does not progress uniformly across patients, and a single average trajectory often fails to capture this heterogeneity. Understanding variation in disease progression is important for improving risk stratification and clinical management. 
Objectives: This study aims to characterize the heterogeneity of chronic kidney disease (CKD) progression using longitudinal estimated glomerular filtration rate (eGFR) data and to identify factors associated with distinct progression trajectory patterns. 
Methods: A longitudinal cohort study was conducted using data from the All of Us} Research Program collected between April 23, 2002, and October 1, 2023. Adult participants with repeated eGFR measurements were …

Evaluating The Potential Of Genomic Selection For Grain Yield And Yield Component Traits In South Dakota Winter Wheat, Dante Koupal

Electronic Theses and Dissertations

Wheat (Triticum aestivum L.) is a major cereal crop worldwide, but recent gains in grain yield (GY) have not kept pace with projected demand. GY is a highly quantitative trait with low heritability that requires multi-year, multi-location phenotyping, limiting selection efficiency. Targeting higher heritability yield component traits, such as kernel size and weight, and incorporating them into the genomic selection (GS) pipeline has the potential to accelerate genetic gain for GY. The objectives of this study were to (i) understand the relationship between GY and the kernel-size traits, including thousand kernel weight (TKW), kernel length (KL), kernel width (KW), and …

Improving Human Dimensions Of Conservation Planning: Challenges And Opportunities For Sustainable Conservation Outcomes, Vivian Hulugh

Electronic Theses and Dissertations

Conservation planning is important to ensure both ecological and social benefits of natural resources, including the maintenance of functional ecosystems and stable wildlife populations as well as the provision of resources that communities rely on. Yet, the integration of the human dimensions of conservation planning remains limited in practice. This thesis examines conservation planning in South Dakota and within Joint Venture (JV) partnerships, using qualitative methods to identify challenges and opportunities for more effective and coordinated planning. In chapter one, I examine how collaboration, public participation, and the use of climate information are integrated conservation planning in South Dakota and …

The Spacetime Finite Element Method For Investigations Into Physics Ghost Systems And Time Parallel Preconditioning, Jax Wysong

Electronic Theses and Dissertations

This work operates on two fronts, focusing on interesting physical phenomena before turning our attention to an interesting numerical math problem. First, using the spacetime finite element method (FEM), we investigate a PDE system consisting of two Klein Gordon equations, which are coupled nonlinearly through the potential energy. The system contains a ghost (negative kinetic energy term). Systems such as these are generally deemed physically unstable, resulting in infinite energy in finite time. However, recent work has shown that this is not always the case. We investigate multiple scenarios arising from different initial conditions to characterize if/when a ghost system …

Feasibility Study For Lithium Mining In South Dakota, Neha Karna

Electronic Theses and Dissertations

The increasing demand for lithium in the battery manufacturing industry, boosted by the growth of electric vehicles and smartphones, has led to concern over its sustainable supply chain in the United States. Historically, South Dakota has played a significant role in U.S. lithium production. The recent surge of interest in lithium exploration in South Dakota, specifically Black Hills, underscores the importance of evaluating the feasibility of lithium mining in Black Hills. This research aims to study the economic feasibility of a lithium mining operation in Black Hills, South Dakota. Our specific objective is to estimate cut-off grade using Lane’s model …

Chemical Load: An Unseen Herbicide Filter In Restored Prairies?, Rylie Franklin

Electronic Theses and Dissertations

Community Assembly Theory is a framework used to describe the process by which species from a regional species pool disperse and encounter various abiotic and biotic conditions that act as filters, limiting which species will populate a specific local community. Prairie restoration success can be improved by understanding abiotic and biotic filters. As agricultural practices have adopted integrated weed management plans, that include the use of both chemical and non-chemical techniques, another filter needs to be considered during restoration: the chemical load of soils, i.e., herbicide residue from recent on-site applications and herbicide drift from adjacent areas. To examine the …

Towards Energy Access For All: Developing The Lived Energy Experience Index (Leei), Kentina Annie Ishimwe

Electronic Theses and Dissertations

Energy is the fuel that powers the engine of civilization. Energy access metrics ensure that nations continuously work towards providing access for all. However, the prevalent binary indicator fails to consider that energy needs to be usable, accessible, affordable, and reliable. As a result, numerous tiered and multidimensional metrics, such as the Multi-Tier Framework, came about to bridge the gap but proved to be complex and complicated to implement. This study presents the existing literature review, assesses the limitations of current energy access measurement frameworks, and compares household energy needs with reported access statistics. Based on the findings, the Lived …

Finite Mixture Modeling Towards Applications In Material Science And Biomedical Data, Jason Hasse

Electronic Theses and Dissertations

This dissertation contains three chapters on different applications of mixture regression models, broadly in materials science and public health. We begin with a basic application of finite mixture models and regression mixture models. The materials science analysis was performed entirely using data from finite element simulations of the additive manufacturing process via powder bed fusion. Visualization of the clustering solution as applied to the additive manufacturing designs highlighted the intuitive patterns that could be found. These patterns simultaneously yield the regression coefficients and subgroups of the geometric regions, providing a way to predict stresses and strains in a new geometry …

Evaluating Supplementation Strategies Using Precision Livestock Technologies And Energy Based Models In Developing Beef Heifers Grazing Dormant Rangeland, Kali-Jo Bentz

Electronic Theses and Dissertations

Replacement beef heifer development in extensive grazing systems is challenged by variation in forage quality, supplement intake, and animal behavior, all of which influence the ability to achieve targeted growth prior to breeding. Precision livestock technologies (PLT) enable continuous monitoring of individual animal performance, while energy-based nutritional models support individualized supplementation. However, their application under extensive grazing conditions remains poorly understood. Therefore, the objectives of this thesis were to (1) evaluate heifer utilization of multiple precision livestock technologies and their relationship with animal performance and (2) evaluate the accuracy of an individualized energy-based supplementation model by comparing predicted supplement allotments …

Securing Smart Agriculture With Communication-Efficient Federated Unlearning, Ujjwal Pudasaini

Electronic Theses and Dissertations

This thesis addresses the data poisoning attack in smart agricultural systems using federated unlearning, where the contribution of compromised field devices must be removed from the global model under communication constraints. We propose FedSCAN, a three-phase framework that identifies critical layers based on parameter sensitivity, classifies active neurons within these layers through relative weight change analysis, and performs unlearning via sparse low-rank adaptation to active neurons while freezing base model parameters. FedSCAN limits computational overhead to a compact parameter subset, enabling devices to participate in a communication-efficient manner. Experimental results on four datasets demonstrate that FedSCAN achieves up to 426.3× …

Data-Driven Decision-Making Frameworks For Energy Procurement And Dynamic Pricing In Electric Vehicle Charging Networks, Pallavi Khanal

Electronic Theses and Dissertations

The continued growth of electric vehicles (EVs) is increasing the demand for charging infrastructure and creating new operational challenges for charging network operators (CNOs). Uncertainty in charging demand, electricity market prices, and user charging behavior can significantly impact both the economic performance and reliability of charging network operations. To address these challenges, this thesis develops an integrated data-driven framework that combines charging demand modeling, risk-aware energy procurement, machine learning, and reinforcement learning for intelligent EV charging network operation. The research begins by developing queueing-based models to characterize EV charging demand under time-varying and stochastic arrival conditions. Time-varying Mt/M/1 and Mt/M/c …

Spatio-Temporal Demand Forecasting For Optimizing Electric Vehicle Charging Network Operations, Subhamyu Mani Nepal

Electronic Theses and Dissertations

The primary objective of this thesis is to create a framework for modeling, forecasting Electric Vehicle load demand and optimizing the EV charging network operation for Charging network operators. As EV’s popularity grows accurate forecasting of EV charging demand and its effect on the distribution network is critical for the efficient planning and operation of charging infrastructure, as well as for enabling Charging Network Operators to participate effectively in wholesale electricity markets. The first part of the work develops Mt /M/1 & Mt /M/c queuing models calibrated using real-world EV charging data to characterize station-level operations under time-varying arrival rates. …

Effect Of Female Employment On Household Expenditure In Bangladesh, Fatema Binte Sharif

Electronic Theses and Dissertations

Female labor force participation (FLFP) in Bangladesh has increased from 29.2% in 2005–06 to 42.8% in 2022, raising important questions about household resource allocation. This study examines the impact of female employment on household expenditure patterns and challenges the traditional unitary model of decision-making. It focuses on how income controlled by women influences spending across essential and non-essential categories. The analysis uses data from the Household Income and Expenditure Survey (HIES) conducted by the Bangladesh Bureau of Statistics. This research employs Seemingly Unrelated Regression (SURE) approach to estimate budget shares for food, housing, health, education, clothing, and transport. The study …

Detecting And Characterizing Latent Subpopulations Of Classes Via Mixture Models, Andrew Simpson

Electronic Theses and Dissertations

A class of problems in statistical pattern recognition exists in which there is high-dimensional data with few realizations per class, commonly referred to as few-shot learning. Data that arises in forensic source identification, which deals with providing a probabilistic value of evidence with regard to the source of some object, falls into this class of problems. Namely, the data is sampled from a hierarchical sampling process, lives in a high-dimensional space, the number of sources (or classes) tends towards infinity, and there are few observations per source. This can be thought of as a few-shot learning problem. Because of these …

Assistant Principals’ Perspectives And Experiences Concerning Their Influence As Instructional Leaders On Student Achievement In Title I Schools, Courtney J. Charles

Electronic Theses and Dissertations

Abstract

This qualitative descriptive study explored the perspectives and experiences of assistant principals in Title I schools in the context of their instructional leadership responsibilities. The study examined the relationship between assistant principals as instructional leaders in Title I schools and student achievement by addressing research questions related to curriculum implementation, data-driven decisions, school culture, instructional support, and professional development. Moreover, this study used purposeful sampling to select 13 assistant principals from Title I schools, and data were collected through semistructured interviews and analyzed using thematic analysis. Marzano’s focused school leader evaluation model served as the framework for interview questions. …

The Impact Of Synchronous And Asynchronous Preference On The Performance Of Distance Learning Students, Christopher A. Wilson

Electronic Theses and Dissertations

Distance learning is a growing part of education. The transition to distance learning was underway at higher education institutions, but the COVID-19 pandemic forced institutions of all types to rapidly transition to distance learning. The technology that was adapted during this emergency distance learning remained in the classroom once normal instruction resumed. This quantitative study examined two aspects of distance learning technology in education. The study examined student preference for either synchronous or asynchronous instruction through the framework of expectancy theory. Students who were more familiar with the course material were hypothesized to have a higher expectation of success and …

Exploring The Potential Effects Of Read Naturally Live To Support Reading Fluency Development In Diverse Learners, Jovonne Tabb

Electronic Theses and Dissertations

The ability to comprehend and apply knowledge learned through reading is fundamental for individuals to become successful and productive citizens in society. The inability to read fluently and accurately with appropriate pacing and expression significantly inhibits text comprehension. Research suggests that children who do not develop reading fluency are more likely to experience learning and comprehension difficulties throughout their academic careers (Lange, 2019). Computer-assisted interventions (CAI) have demonstrated effectiveness in advancing students' reading fluency, particularly for those at risk of developing reading disabilities or those already diagnosed with reading difficulties. However, a significant gap exists in research examining CAI effectiveness …

Discovery Of The Multi-Ion Bridge Intermediate: A Computational Exploration Of The Mechanism For Azomethine Ylide Formation From N-Oxides, Martin J. Neal

Electronic Theses and Dissertations

Density functional theory (DFT) provides a method for calculating the ground-state energies of complex molecular systems through evaluating the electron density instead of the full wave function. When results match either experimental outcomes, calculations with DFT offer a computationally efficient method to help explain chemical phenomena. The transformation of tertiary amine N-oxides to azomethine ylides, a simple route to the precursor for 1,3-dipolar cycloadditions that result in the pyrrolidine scaffolds found in natural products, has received only minimal attention due to concerns that its mechanism includes a highly electrophilic intermediate. Utilizing DFT to model the mechanism of the conversion …

Limiting A Liberal Education: Exploring Technology Access And Equity Through Universal Design And Critical Disability Studies, Marisa R. Carlson

Electronic Theses and Dissertations

This quantitative improvement study investigates how classroom technology policies impact equity, access, and alignment with liberal arts values at a small Catholic liberal arts college. The study arose from concerns regarding academic accommodations, where students needed to formally request access to digital tools that were widely available. The focus is on inconsistent and sometimes restrictive technology policies that create barriers for students relying on these resources.

Interpreted through the conceptual frameworks of Universal Design for Learning (UDL) and Critical Disability Studies (CDS), this study was guided by the following research questions:

1. What expectations do students have regarding access to technology …

A Sedimentary Source Of Rare Earth Elements In The North Atlantic, Rylee D. Lindner

Electronic Theses and Dissertations

Individually and as a series, the Rare Earth Elements (REEs) are powerful geochemical tracers of environmental processes. However, ambiguities in the oceanic budgets of the REEs hamper their application. Growing evidence suggests a sedimentary benthic flux via the pore water is the major source of REEs to the ocean, with extrapolated estimates of this flux being equivalent in magnitude to that “missing” from modern budgets. However, existing pore water REE data are available from only a few locations globally with no representative dataset from the open North Atlantic. This data scarcity limits our ability to constrain flux estimates and understand …

Molecular Dynamics Simulations Of Biologically Relevant Interfaces: From Tear Film Lipid Layers To Rna Adsorption On Silica Surfaces., Mahbuba Khanom

Electronic Theses and Dissertations

Molecular dynamics (MD) simulation is an important tool in biochemical sciences for studying complex molecular processes and interfacial interactions at the molecular level. Biological interfaces play key roles in processes such as ocular lubrication and biomolecular adsorption. This dissertation studies interfacial phenomena involving two distinct yet conceptually related systems: the tear film lipid layer (TFLL) at the air–water interface at the surface of the human eye, and RNA adsorption on silica surfaces. These studies provide insight into how interfacial composition, structure, and environmental conditions affect larger-scale behavior. Atomistic MD simulations were used to model the TFLL. The TFLL is essential …

Impacts Of Biology Modeling Pedagogy On Student Cogitive And Non-Cognitive Elements Of Learning., Jessie K. Newhouse

Electronic Theses and Dissertations

This dissertation employed a quasi-experimental design used to investigate the use of a modeling pedagogy in high school biology. Modeling is a key element of the Science and Engineering Practices of the Next Generation Science Standards. While research of Model Based Pedagogy (MBP) in physics and chemistry is well established, the influence on biology instruction remains less understood. This research examined how MBP affected both cognitive and non-cognitive components of student learning compared to traditional biology instruction. Existing data collected by Dr. Kathy Malone in collaboration with Ohio State University (2016) were analyzed to study the effectiveness of the MBP. …

Thermal And Non-Thermal Mass Transport Effects In Plasmon-Assisted Electrochemistry., Md Al Amin

Electronic Theses and Dissertations

Plasmon-assisted electrochemistry has received attention due to its effects of hot charge carriers, photothermal heating, and enhanced electromagnetic field impact on electrochemical transformation. These effects have contributed to lowering the onset potential and increasing the reaction kinetics. Numerous studies have been employed to differentiate the effect of photothermal heating from hot charge carriers on the electrochemical reaction. Most of these studies have been employed to measure and quantify the photothermal heating effects at equilibrium temperature; however, localized heating from the incident light does not result in homogeneous heating across the electrochemical cell. Many studies investigating the photothermal heating effect in …

A Persistent Homology Framework For Scrna-Seq: Assessing Clustering Robustness And Quantifying Preprocessing And Integration Effects On Topological Features., Jonah Daneshmand

Electronic Theses and Dissertations

As single-cell RNA sequencing (scRNA-seq) data expands, robust methods for integrating diverse datasets are critical. This dissertation applies Persistent Homology (PH), a technique from Topological Data Analysis (TDA), to a collection of scRNA-seq datasets spanning eight tissue types to quantify how data integration affects topological features and biological interpretability. We assessed global topological structure using Betti curves, Euler characteristics, and persistence landscapes across raw, normalized, and integrated data representations. Our analysis revealed a performance inversion: while conventional methods excelled on unintegrated data, high-granularity topological methods, particularly those sensitive to global data structure, became superior after integration. This suggests a synergy …

Controlling Selectivity In Electrocatalytic Co2 Reduction With An External Magnetic Field., Nawaraj Karki

Electronic Theses and Dissertations

My dissertation describes how to alter the speciation and concentration of molecules at the electrode-electrolyte interface, and how those alterations affect reactivity and selectivity. This dissertation presents two distinct approaches to control the mass transport of neutral molecules such as carbon dioxide (CO₂) at the electrode-electrolyte interface by using an external magnetic field. The first finding demonstrates that magnetic fields indirectly affect the mass transport of target analytes such as CO₂ molecules by selectively interacting with charged species, such as hydroxide ions (OH^-). Such interaction induces magnetohydrodynamic (MHD) effects, which generate localized hydrodynamic flow and …

Preparing Confident Elementary Mathematics Teachers: Addressing Anxiety, Building Fluency, And Strengthening Practice., Amber Diamond Pendleton

Electronic Theses and Dissertations

This dissertation, presented in three articles, examines how elementary preservice teachers (PSTs) experience and develop as mathematics learners and future educators when methods coursework deliberately integrates mathematical reasoning with affective supports. Collectively, the studies investigate how research-informed instructional design may help address mathematics anxiety (MA), mathematics teaching anxiety (MTA), procedural fluency, and instructional practice. The first article, written for practitioners and elementary mathematics teachers, illustrates how well-established instructional routines, such as number talks and student work analysis, can be facilitated to support procedural fluency in multiplication. Using classroom vignettes, this article highlights instructional moves that make structure visible, promote strategy …

Plasma-Enhanced Carbon Nanomaterial Synthesis: A Pathway To Reducing Greenhouse Gasses And Carbon-Based Waste., Zane Ronau

Electronic Theses and Dissertations

This research leveraged incorporation of capacitively coupled radio frequency plasma into chemical vapor deposition (CVD) for a reduction in the temperature requirements [a reduction of energy barrier] needed for the conversion of methane (CH₄), carbon dioxide (CO₂), and various carbon-based-waste to produce value-added carbon nanomaterials. An array of catalysts and catalyst supports were employed to optimize the synthesis of graphitic carbon under various gas environments, temperatures and pressures. The nanomaterials synthesized after fine tuning the growth parameters included graphene, carbon nanotubes (CNT), carbon microtubes and carbon nanocages with a variety of properties. Raman Spectroscopy was used …

Direct And Satellite-Based Quantification Of Greenhouse Gas Fluxes In Small Ponds., Mark Christopher Tierney

Electronic Theses and Dissertations

As evidenced by their historic losses due to anthropogenic activities, wetlands are undervalued ecosystems that provide numerous ecosystem services, from recreational opportunities to carbon (C) storage. However, these wetlands are also the largest natural source of atmospheric methane (CH₄). Additionally, small water bodies (< 10,000 m²) are disproportionately large emitters relative to larger lakes and reservoirs. As construction and restoration efforts proceed, it is crucial to identify wetlands that need restoration and to understand the factors driving both greenhouse gas (GHG) fluxes and the C balance of these systems. This dissertation investigates the drivers of greenhouse gas fluxes …