Digital Commons Network^™

Assessment Of Simulation Software Used For Cubesat Gnc Verification And Validation By University Research Teams, Alexander Taiyo Newett

Masters Theses

As the growth in university satellite teams continues, along with the greater trend in the small satellite market, the need for a guidance, navigation, and control verification and validation pipeline suitable for these young and inexperienced teams becomes evident. Much of the mathematical theory and software implementation of GNC concepts are large hurdles for teams largely composed of undergraduate students.

Many software packages exist that can help these teams achieve GNC verification and validation. If the learning curves of these software packages can be overcome, new satellite teams have the opportunity to better build and test GNC algorithms that are …

Assessment And Comparison Of Selected Carbon Ablation Models In Hypersonic Free-Flight And Arc-Jet Conditions, Andrew Steven Heider

Masters Theses

Accurate prediction of ablative thermal protection system (TPS) performance is critical for hypersonic vehicle design. However, numerical prediction of ablation remains challenging because results are influenced by complex physics and the choice of surface chemistry model and assumptions made in material response calculations. The objective of this work is to evaluate several carbon ablation models and their implementation within modern computational fluid dynamics (CFD) codes. Numerical simulations were performed using NASA’s LAURA flow solver and the commercial CFD code ANSYS Fluent, which coupled Navier-Stokes with surface chemistry models describing carbon oxidation, nitridation, and sublimation reactions. Several reaction sets were considered, …

Optimal Slotting In Hybrid Warehousing For Industry 4.0, Teng Yang

Masters Theses

In the era of Industry 4.0, the warehouse management system (WMS) employed by many firms prescribes hybrid storage, i.e., products with high turnover, called fast movers, are kept in random storage for a short time duration before being shifted to a dedicated storage area, while products with low turnover, called slow movers, remain in random storage. From dedicated storage, the products are dispatched to the customer. The challenge for managers is selecting the slot in dedicated storage to assign to each product while demand data change because of fluctuating market conditions; this problem is referred to as slotting in the …

Validating A Low-Cost Radio Frequency Characterization Framework For Development-Grade Software-Defined Radios In Short-Duration Cubesat Missions, Thomas Wayne Francois

Masters Theses

Software-defined radios (SDRs) and CubeSat platforms have reduced the cost and complexity of space-based communication systems, enabling broader participation in satellite missions. While low-cost radio hardware is increasingly accessible, the ability to characterize and validate its performance remains constrained by the high cost and limited access to traditional RF test equipment. This disparity creates a challenge for small satellite development teams, which must characterize communication-system technical performance with limited access to laboratory-grade instrumentation.

This thesis presents a low-cost RF characterization framework for assessing key radio-frequency performance metrics using readily available hardware and measurement techniques. The approach integrates frequency translation, SDR-based …

Design For Extrusion-Based Additive Manufacturing: Generation Of Guidelines For Ceramics With Comparison To Thermoplastics, Hollis Hervey Waites

Masters Theses

"Design for Additive Manufacturing (DfAM) has made much progress for polymer material extrusion processes (MEX-P), like Fused Deposition Modeling (FDM), but very little progress for ceramic MEX processes (MEX-C) like Direct Ink Writing (DIW). This thesis leverages MEX-P design guidelines to create an initial set of design guidelines for DIW. FDM and DIW processes and material properties are compared, and the effect of these factors on the differences in rules is discussed. Five design guidelines are identified as applying to all MEX. For three of these, an exact limit for DIW of alumina is studied: minimum corner radius in the …

Cervical Ligament Systems In Sauropod Dinosaurs: What Support Is There?, Audrey Rose Williams

Masters Theses

"Sauropod dinosaurs, such as Diplodocus, have been the subject of numerous hypotheses about what ligamentous structures could have lifted and supported their long necks. Because the supportive tissues rarely fossilize, palaeontologists rely on osteological correlates on the bone to infer their nature. Options for supportive cervical ligaments in sauropods are mammal-style nuchal ligaments, avian-style interlaminar elastic ligaments, reptilian-style supraspinal ligaments, or some combination thereof. This study tested for the presence of a mammal-style nuchal ligament via histological and micro-computed tomography of posterior cervical hemispinous processes of Apatosaurus and Diplodocus, in addition to examining gross morphological features of the cervical vertebrae …

Transformer-Based Language Models For Bitcoin Market Prediction And Interpretation, Erich Gozebina

Masters Theses

"In the context of a Master's thesis in applied mathematics, this work investigates compact transformer-based language models as an instrument for Bitcoin-related predictions and decision support. The work connects three topics: the structure of the Bitcoin system and its data, the mathematical and algorithmic foundations of deep autoregressive transformers, and the design of practical training pipelines for financial applications. On this foundation, a reproducible ETL pipeline for Bitcoin data is developed and two forecasting experiments are conducted with the compact language model nanochat. The first experiment approaches the prediction of next-day price movements through autoregressive next-token generation based on structured …

Characterizing A Delay-Programmable Two-Color Femtosecond Light Source For Coherent Control Of Atomic Multi-Photon Ionization Processes, Mason Tanner Toombs

Masters Theses

"In this work a delay-programmable two-color femtosecond laser based on a chirped-seed noncollinear optical parametric amplifier was characterized. This design utilizes a titanium-sapphire crystal oscillator to generate broadband pulses of light spanning approximately 600-1200 nm, with a pulse duration of ~5 fs, repetition rate of 80 MHz, and pulse energy of ~2.5 nJ. An infrared portion of the light, spanning approximately 1020-1060 nm, is split off from the pulse and used to generate a pump beam. By dispersing the remaining seed beam and controlling the relative timing delay between the seed and the pump, tunable frequencies within the seed can …

The Occurence Of Expansive Clay Soils In Illinois And Their Effects On Shallow Lightly Loaded Foundations, Greg James Gollaher

Masters Theses

"The damage caused to shallow foundations and slabs on grade by the shrink-swell activity of clay soils is well documented across the United States. There are local and national resources available that delineate areas that are problematic and areas that are not. These resources paint Illinois as an undemanding foundation environment. However, our experience differs from this. Our experience tells us that damage related to the shrink-swell activity of clay soils is widespread, and commonly severe causing not only cosmetic damage to structures and hard improvements but also affecting the serviceability and longevity of structures. My goal is to accurately …

Structured Decomposition And Efficient Adaptation For Scientific Data Movement: From Transfer Concurrency To Genomic Data Acquisition, Rasman Mubtasim Swargo

Masters Theses

"The end-to-end performance of scientific data movement is increasingly limited not by raw network capacity but by whichever resource along the path is momentarily slowest, a bottleneck that no single static configuration can track. This thesis argues that the right response is to decompose each problem along the resource or workflow axis where bottlenecks vary, adapt only the genuinely dynamic control variables at runtime, and make that adaptation efficient through utility-guided or offline-learned control rather than expensive online search. The thesis develops this principle through four systems of widening scope. AutoMDT decomposes a transfer by operation, assigning separate concurrency levels …

Pedagogical Moves For Provoking Prospective Teachers’ Intellectual Needs While Connecting Abstract Algebra And Secondary Mathematics, Kaitlyn Stephens Serbin, Estrella Johnson, Sthefanía Espinosa

School of Mathematical & Statistical Sciences Faculty Publications

Researchers have exhibited ways in which prospective secondary mathematics teachers can connect content from abstract algebra with secondary mathematics in ways that reshape their understanding of secondary mathematics and thereby support their teaching of that content. However, there has been very little research done on what mathematics teacher educators can do in the classroom to help prospective teachers make connections between abstract algebra and secondary algebra in ways that support such reshaping. This study focuses on a mathematics teacher educator who guided a class of prospective teachers to connect properties of algebraic structures with equation-solving procedures by directing their focus …

Traveling Waves For A Diffusive Sir Epidemic Model With Delay In The Diffusion Term, William Barker

Faculty Scholarship

This paper investigates the existence of traveling waves in a diffusive SIR model with delay incorporated in the diffusion terms and a nonlinear incidence rate with delay. By employing a cross-iteration scheme and partial monotonicity conditions, we establish that the existence of quasi-upper and lower solutions, along with suitable super and sub-solutions, provides sufficient conditions for the existence of a traveling wavefront. This existence result is obtained via Schauder’s fixed-point theorem. Furthermore, given an appropriate basic reproduction number, the traveling wavefront transitions from the disease-free steady state to the endemic steady state. To illustrate our approach, we explicitly construct super- …

A Universal Hybrid Model-Free Deep Quantum–Transfer Learning Controller Enhanced By Grey Wolf Optimization For Dc–Dc Boost Converters With Hardware-In-Loop Validation, Seyyed Morteza Ghamari, Asma Aziz

Research outputs 2022 to 2026

This paper proposes a universal hybrid model-free quantum–transfer learning controller with enhanced online grey wolf optimization algorithm (GWO–QTL) for DC–DC boost converter. This system has the characteristics of non-minimum phase behavior, parasitic effects, and fractional-order dynamics because of high frequency operation. These characteristics make analytical modeling complicated and make it difficult to have a single traditional controller that will operate reliably over different converter types. This motivates the creation of a unified model-free control framework that is able to learn directly from the behavior of the converter without relying on the topology specific models. Reinforcement learning, where an agent interacts …

Does Class Ability Grouping In Secondary Schools Improve Students’ Literacy Scores On Australia’S Naplan Tests?, Olivia Johnston, Christa Norris, Peter Palamara

Research outputs 2022 to 2026

Many schools choose to use ability grouping, despite longstanding evidence that it is inequitable and does not improve overall academic outcomes. One reason that the practice of grouping students by ‘ability’ continues is because of pressure to perform on standardised tests. Educators hold beliefs that grouping students for English classes, for example, will improve their literacy scores. This paper presents findings from a study about class ability grouping for English in Australia and how different class grouping practices relate with students’ achievement on Australia’s standardised literacy test. The findings draw on data from our Class Ability Grouping Survey, where participant …

Maternal Prebiotic Supplementation Modifies Associations Between Intrapartum Antibiotics And Infant Allergy, Summer V.M. Walker, Thomas R. Sullivan, Rachelle A, Pretorius, Nina D'Vaz, Johnny Lo, Johan Garssen, Jeffrey A. Keelan, Desiree Silva, Susan L. Prescott, Claus T. Christophersen, Debra J. Palmer

Research outputs 2022 to 2026

Background: Prebiotics promote growth of beneficial gut bacteria, whereas antibiotics can disrupt the microbial balance, reduce diversity, and potentially cause gut dysbiosis. This investigation aimed to determine whether antibiotic use before, during, or after birth altered the risk of infant allergic disease outcomes within a maternal prebiotic dietary supplementation trial. Methods: Maternal participants were allocated to consume daily prebiotics (galacto-oligosaccharides and fructo-oligosaccharides) or placebo (maltodextrin) powder from 18 to 20 weeks' gestation until 6 months postnatal. All infants had a family history of allergic disease. Maternal and infant antibiotic use was prospectively collected monthly throughout the trial intervention period, and …

Measuring Teachers’ Beliefs In Their Capacity To Use Differentiated Instruction In Their Classrooms: Development, Validation And Confirmation Of A Self-Efficacy Scale, Kathryn Gibbs, Stuart Woodcock, Nicole Dargue, Leah Le, Eunjae Park, Tom Porter, Gemma Scarparolo

Research outputs 2022 to 2026

The purpose of this study was to develop, validate and confirm a scale to gain a better understanding of teachers’ beliefs in their capacity to use differentiated instruction in their classrooms. Differentiation is an effective approach to teaching, designed to enable equitable learning opportunities for every student. Teachers are recommended to differentiate aspects of teaching, instruction, learning, assessment and the learning environment due to the increasing student heterogeneity within classrooms worldwide. Emerging literature has suggested that teacher self-efficacy may influence how teachers use this teaching approach. It is unknown if there is an existing scale that measures teachers’ self-efficacy when …

What Are Information Literacy Skills? Western Australian Primary Teachers’ Interpretations Of The Ict Curriculum, Louise Moroney, Vaille Dawson

Research outputs 2022 to 2026

Teachers must equip students to navigate an increasingly complex world of unique challenges and opportunities, necessitating the development of a diverse range of transferable skills. These skills are embedded in the General Capabilities (GC) of the Australian school curriculum. Upper primary school teachers’ interpretations of one of the GC, Information and Communication Technology (ICT) learning progressions, was examined, as these skills have become increasingly important with the rise in generative and assistive artificial intelligence. Using an interpretivist paradigm, an exploratory study was used to determine the areas where 36 teachers differed in their interpretations of the learning progression. Data collected …

Design Of Artificial Interference Signal Waveforms For Covert Communication Aided By Multiple Friendly Nodes, Xuyang Zhao, Wei Guo, Yongchao Wang, Shihao Yan

Research outputs 2022 to 2026

In this work, we consider a covert communication scenario with multiple friendly interference nodes. The goal is to hide a legitimate communication link from a transmitter to a receiver under a warden’s surveillance. Firstly, we propose a novel strategy for generating artificial noise (AN) signals and formulate a corresponding design problem, aiming to minimize the adverse effects of AN on the legitimate receiver while enhancing communication covertness. Specifically, we optimize the basis matrix for AN signal space using statistical information of the involved channel coefficients, when precise channel state information are unavailable. Secondly, we analyze the geometric structure of the …

Optimizing Ev Battery Charging Using Fuzzy Logic In The Presence Of Uncertainties And Unknown Parameters, Minhaz Uddin Ahmed, Md Ohirul Qays, Stefan Lachowicz, Parvez Mahmud

Research outputs 2022 to 2026

The growing use of electric vehicles (EVs) creates challenges in designing charging systems that are smart, dependable, and efficient, especially when environmental conditions change. This research proposes a fuzzy-logic-based PID control strategy integrated into a photovoltaic (PV) powered EV charging system to address uncertainties such as fluctuating solar irradiance, grid instability, and dynamic load demands. A MATLAB-R2023a/Simulink-R2023a model was developed to simulate the charging process using real-time adaptive control. The fuzzy logic controller (FLC) automatically updates the PID gains by evaluating the error and how quickly the error is changing. This adaptive approach enables efficient voltage regulation and improved system …

Professional Development To Inspire, Support, And Extend Stem-Related Learning, Somayeh Ba Akhlagh, Asma Hulayyil Aljohani, Maryam Jamal Alharthi, Nahla Mahmoud Gahwaji, Nouf Mohammed Albadi, Marianne Knaus

Research outputs 2022 to 2026

The success of STEM education in early childhood education is reliant on the pedagogical practices of teachers. Effective teaching of STEM requires specific knowledge of the four disciplines of STEM, appropriate teaching and learning methods and relevant experiences. In Saudi Arabia the teaching of STEM is a relatively new field, and this paper outlines a research project to promote the teaching and learning of STEM through professional development workshops. The research is informed by Vygotsky’s cultural-historical/socio-cultural theory, acknowledging the crucial role of social interaction and cultural context in a collaborative learning environment. To evaluate the project, a mixed methods approach …

Mobility Of Hydrophilic And Hydrophobic Nanoparticles In Carbonate Reservoirs: Application To Subsurface Projects, Zain Ul Abedin Arain, Sarmad Al-Anssari, Muhammad Ali, Faisal Ur Rahman Awan, Alireza Keshavarz, Jitendra Sangwai, Mohammad Sarmadivaleh, Stefan Iglauer

Research outputs 2022 to 2026

Nanoparticles (NPs) have been suggested for subsurface projects, including enhanced oil recovery (EOR), carbon capture and storage (CCS), and hydrogen storage, due to their small size, high surface energy, controlled surface properties, and significant effects on the underground formation properties. Silica is an excellent NP that efficiently modifies the surface properties of subsurface formations for incremental oil recovery and to derisk carbon and hydrogen leaks. However, the retention of injected NPs in a narrow area near the injection inlet can limit a project’s feasibility. In the present study, hydrophobic (hybrid) NPs were produced via silanization of silica NPs, and the …

Baseline Body Mass Index Category And Incident Treated Hypertension In Australian Men: A Linked Prospective Cohort Study Using Pbs/Mbs Data, Ebenezer Afrifa-Yamoah

Research outputs 2022 to 2026

Background: Excess adiposity is a major modifiable risk factor for hypertension; however, the incremental prognostic value of body mass index (BMI) beyond standard predictors remains unclear. We examined the associations between baseline BMI category and incident treated hypertension, and assessed whether BMI improved risk prediction.

Methods: Data were obtained from the Ten to Men longitudinal study (2013–2024) linked to Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Schedule (MBS) records. The cohort comprised 12,742 men aged ≥ 18 years without treated hypertension at baseline, followed for 133,038 person-years. Adjusted Cox proportional hazards models were fitted. Discrimination, calibration, decision curve analysis, E-values, …

Load-Settlement Behaviour Of Tailings Dam Foundation Strengthened Using The Wraparound Geosynthetic Reinforcement Technique, Francis Otieno, Sanjay Kumar Shukla

Research outputs 2022 to 2026

This paper presents a numerical investigation of the load–settlement behaviour of a geosynthetic-reinforced tailings foundation comprised of gold tailings, subjected to the weight of a tailings dam embankment. The study considered varying conditions, including the horizontal and vertical components of the wraparound reinforcement, reinforcement burial depth, and shear strength parameters of the foundation material. A particular focus of this study is to investigate the effect of reinforcement wraparound ends on the settlement behaviour of the foundation using commercially available finite element (FE) software. The reinforcement is a single-layer biaxial woven geotextile, with and without wraparound ends, at varying depths from …

The Lawyer Of The Future: Ethics And Identity In The Age Of Ai, David Yosifon, Michael Santoro, Isaac Nikssarian

American University Law Review

The dawn of artificial intelligence (AI) poses a fundamental challenge to the legal profession’s practical function and social identity. We argue that this challenge should be met as an opportunity to reclaim the profession’s core ethical intentions. We approach the emergence of AI as an occasion to define and safeguard what is irreducibly human in legal work. We ground our approach in the ethical imperatives set out in the American Bar Association’s Model Rules of Professional Conduct, while extending them into an invigorated framework for the AI era.

We survey the uses and ethical challenges associated with cutting-edge deployment of …

Healthcare Provider Perspectives On A Clinical Decision Tool To Support Individualized Exercise Prescriptions And Discussions For Breast Cancer Survivors, Jinani Jayasekera, Oliver W. A. Wilson, Kaitlyn M. Wojcik, Eleanor M. Kerr, Rachelle Brick, David Berrigan, Jennifer Yeong-Shin Sheng, Takeo Fujii, Kathleen Thomas, Henri K. Parson, Padma Sheila Rajagopal, Richard L. Street Jr.

Department of Medicine Faculty Publications

Purpose: We evaluated healthcare providers' current knowledge, practices, and perspectives on a novel clinical decision tool (beta-version) to facilitate individualized exercise prescriptions and discussions in clinical settings.

Methods: We recruited healthcare providers who had treated or provided care to breast cancer survivors aged >= 35-years in the past 12 months. The participants were presented with a tool to provide individualized exercise recommendations considering women's individual, clinical, and contextual characteristics. Validated and reliable pre-existing instruments were used to survey providers' current knowledge, practices regarding exercise discussions, and perspectives on the beta-version (paper-draft) of the novel tool.

Results: The sample consisted of …

Tyranny Of A Feather: Asymmetry In Civil Burdens Of Proof, Thomas O. Main

American University Law Review

Civil litigation suffers from a paradox that is at once self-evident, unfair, and overlooked: the trial process promises equality between plaintiffs and defendants under the preponderance-of-the-evidence standard, even as the pretrial process is skewed dramatically in defendants’ favor. At trial a plaintiff needs only “50% plus a feather” to tip the scales and prevail, reflecting a commitment to equal treatment of the parties. Pretrial, however, the playing field tilts steeply: plaintiffs alone must navigate a procedural gauntlet of motions that impose pleading and production burdens for which defendants face no equivalent. This entrenched asymmetry in pretrial practice has become so …

Elevated Sulfate Concentrations In Groundwaters Of Glaciated Terrains—Natural Or Anthropogenic?, Christabel Obi, Eric W. Peterson

Faculty Publications - Geography, Geology, and the Environment

Increasing sulfate (SO₄²⁻) concentrations in groundwater systems are a growing environmental concern due to their implications for drinking-water quality and biogeochemical cycling. While sulfate is commonly of geogenic origin, its behavior in agriculturally influenced glacial aquifers remains poorly constrained. This study investigates the distribution, depth dependence, and seasonal variability of sulfate concentrations in groundwater within a riparian system comprised of sediments deposited by glaciers in central Illinois, USA. The study specifically evaluates whether sulfate concentrations 1) vary with groundwater depth, 2) exhibit seasonal trends, and 3) reflect contributions from agricultural tile drainage waters. Groundwater samples collected from …

A Quantitative Analysis Of Barriers To College Students’ Seasonal Vaccination Intentions And Behaviors, Kelly S. Clemens, John Matkovic

Faculty Publications – Health Sciences

Objective
Vaccination is crucial to college student health, but quantitative analyses of barriers in this population are limited. The present study expands the work of Su and Chen to determine the relative influence of structural, psychological, and social vaccination barriers.

Participants
Participants were 650 students from a large, midwestern university during the 2024 vaccination season.

Methods
Participants were recruited from a college campus and randomized to respond to items assessing their barriers to, intentions to receive, and uptake of the COVID-19 or influenza vaccination.

Results
Structural, psychological, and social barriers were differentially important to vaccinations and to intentions vs. uptake …

Exponentially Many Correspondence Colourings Of Planar And Locally Planar Graphs, Luke Postle, Evelyne Smith-Roberge

Faculty Publications – Mathematics

We show that there exists a constant c>0 such that if G is a planar graph with a 5-correspondence assignment (L,M), then G has at least 2c⋅v(G) distinct (L,M)-colourings. This confirms a conjecture of Langhede and Thomassen. More broadly, we introduce a general method showing how hyperbolicity theorems for certain families of critical graphs can be used to derive lower bounds on the number of colourings of the associated class of planar graphs. Hence our main result follows from this method plus a technical theorem (that we proved in a previous paper) involving the hyperbolicity …

Energy Poverty, Economic Growth And Environmental Degradation In South Asia: Do Energy Resources Matter?, Memona Rasheed, Hooi Hooi Lean, Nam Foo

Research outputs 2022 to 2026

Developing countries can combat energy poverty by enhancing renewable energy and economic growth with minimal adverse environmental effects. In this paper, we present a comprehensive analysis of energy poverty, renewable energy, economic growth, carbon dioxide emissions, and urbanization (URB) in South Asian countries from 1990 to 2021, focusing on Pakistan, India, Bangladesh, and Sri Lanka. We employed econometric analysis techniques like Panel Pooled Mean Group (PMG)-Autoregressive Distributed Lag (ARDL), Fully Modified Ordinary Least Squares (FMOLS), and Dynamic Ordinary Least Squares (DOLS) to provide empirical results, as they enable panel data and control for endogeneity. The findings suggested that the fight …