Digital Commons Network^™

Wavelength And Luminance Interaction On Spatio-Temporal Contrast Sensitivity Function, Taylan S. Ergun

Dissertations, Theses, and Capstone Projects

Contrast sensitivity (CS) measures the ability to discriminate objects from their backgrounds under varying conditions(Campbell & Robson, 1968). Contrast sensitivity is important for navigating the real world and operating under different light conditions. The contrast sensitivity function (CSF) reflects how the visual system performs under different conditions. This measure is crucial in assessing the health of the visual system (Chen & Gardner, 2021). CSF contributes to a deeper understanding of how the visual system processes and integrates properties of light to create visual sensation and perception. Human contrast sensitivity depends on the viewing conditions such as field size, luminance, color, …

Developments In The Lithographic Engineering Of Bi2sr2cacu2o8+Delta Mesa Terahertz-Emitting Devices, Sarah Elghazoly

Dissertations, Theses, and Capstone Projects

Devices microfabricated from the high-temperature superconducting cuprate Bi₂Sr₂CaCu₂O_8+𝛿 (Bi-2212) are a promising source of coherent terahertz radiation within the ’terahertz gap’ (0.3- 1.5 THz). A current-biased mesa patterned into the surface of a single crystal will produce electromagnetic radiation in the terahertz regime due to the naturally occurring Josephson junctions formed by the stacks of superconducting cuprate oxide planes in the material separated by insulating BiO and SrO barrier layers. Previous research has shown that by fabricating these mesas such that the geometry supports resonant cavity Fabry-Perot modes, the junctions within the mesa …

The Role Of Water In Peptide Behavior And Peptide-Based Water-Responsive Crystals, Janel Jannette Rivera Cancel

Dissertations, Theses, and Capstone Projects

Water plays a crucial role in shaping the behavior and function of biomolecules across the liquid, supercooled, and glassy states. This thesis presents a dual approach combining computational simulations and experimental investigations to explore the influence of water on biomolecular systems, particularly peptide-based materials. We employ molecular dynamics simulations to study the hydration-dependent structural dynamics of homopolymer peptides. Simulations were carried out across a range of temperatures and pressures to analyze changes in hydration and structural stability, shedding light on the behavior of peptides under supercooled and glassy conditions. These studies are especially relevant for understanding biomolecular stability in cryopreservation. …

Satellite-Host Galaxy Co-Evolution With Next-Generation Regulator Models, Austen Gabrielpillai

Dissertations, Theses, and Capstone Projects

The evolution of satellites galaxies is an unsolved problem in galaxy formation. Recent observations such as the SAGA and ELVES surveys find tension in HI contents and star formation of satellites around their central host galaxies when compared to our own local environment, the Milky Way. These processes are potentially highly influenced by the host's circumgalactic medium (CGM), and to constrain these cases requires accurate and fast modeling of satellites-host interactions. In this work, we present our methodology for evolving z = 0 surviving satellites alongside their central galaxy in sapphire, a CGM regulator co-evolution model of galaxy formation. …

Tradition, Individuality, And Innovation In Western Classical Music Performance: A Quantitative Analysis Of Bach’S Fourth Cello Suite Prelude, Clare Monfredo

Dissertations, Theses, and Capstone Projects

Why do we seek out new performances of a commonly performed piece of music? An essential tradition of Western classical music (WCM) is the performance of canonical works by composers, an activity that requires the interpretation and execution of written scores by individual performers. In this practice, performers are not only expected to determine the composer’s “intentions,” but also somehow (paradoxically) share these in a “unique” performance interpretation. In musical education, performers are trained by teachers to create these “unique” interpretations by learning how to intuit composers’ intentions in a system that passes down interpretative traditions through master-apprentice one-on-one lessons. …

Coding Anti-Discrimination Jurisprudence: A Hybrid Computational Model Of The Arlington Heights Test, Kevin S. Jobe

Philosophy Faculty Publications

The aim of this study is to understand the judicial reasoning process of anti-discrimination jurisprudence by utilizing a hybrid computational model. The advancement of hybrid computational legal studies that combine “law-as-code” and “law-as-data” approaches have led to promising techniques for tackling complex legal reasoning tasks as multifactor judicial reasoning standards. Following this hybrid model, this study conducts a statistical and multilayer perceptron (MLP) analysis of the judicial reasoning process of the multifactor Arlington Heights discriminatory purpose test based on an original hand-coded dataset of discrimination cases. The results of the study show that “sequence of events” predominates the other factors …

Futurescape Libraries Ai Toolkit, Keith Webster

Copyright, Fair Use, Scholarly Communication, etc.

A toolkit developed to explore scenario-specific strategies and activities that research libraries can undertake to prepare for various possible AI-influenced futures. The toolkit integrates the ARL/CNI AI Scenarios published in spring 2024 along with priorities trialed and refined by strategic thinkers working directly in, or adjacent to, the research library field during a Strategic Implications forum held December 7–8, 2024, in Washington, DC.

Missing The Mark: The Cost Of Overlooking Black Students’ Cultural Capital, Christine L. Quince

Teacher Education

Historically, educators and policymakers have viewed Black students from a deficit lens, often presuming they lack the necessary skills needed to become academically successful. Today, teachers have countered deficit framing of Black students by learning more about and incorporating Black students’ assets and critical views of the world into their learning. One issue teachers run into, however, is knowing how to incorporate Black students’ cultures in their classroom learning. Using an embedded case study, this study analyzes how one white teacher draws on Black students’ cultural capital and the ways it impacts students’ classroom experiences. Findings reveal that disconnecting Black …

Nocturnal Foraging By Great Blue Heron (Ardea Herodias) And Roseate Spoonbill (Platalea Ajaja), Laura E. Josler, Johnny E. Owens, Sarrah E. Bristol, Leo N. Dutkewych, Abigail R. Kauke, Signe E. Renstrom, Ben G. Sheffield, Madelyne E. Vashaw, Avery J. Nesbitt, Melia K. Paat, Timothy D. Bransford, Elizabeth A. Forys

Florida Field Naturalist

The Great Blue Heron (Ardea herodias) and Roseate Spoonbill (Platalea ajaja) are long-legged wading birds that can forage throughout a 24-hour cycle. Nocturnal foraging enables these species to take advantage of optimal foraging conditions and reduced competition. This study aims to investigate how environmental factors influence the nocturnal foraging behavior of these species. To monitor foraging activity, we deployed 17-18 infrared cameras from dusk until dawn from 4 October 2023 to 24 July 24 2024, covering two sampling periods across different habitats within Fort De Soto County Park, a barrier island complex in Tampa Bay, Florida. We compared the frequency …

Frsc 359-003: Physical Methods Of Forensics, Kevin Parmelee

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

Physics-Based Machine Learning Framework For Predicting Structure-Property Relationships In Ded-Fabricated Low-Alloy Steels †, Atiqur Rahman, Md Hazrat Ali, Asad Waqar Malik, Muhammad Arif Mahmood, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Directed Energy Deposition (DED) process has demonstrated high efficiency in manufacturing steel parts with complex geometries and superior capabilities. Understanding the complex interplays of alloy compositions, cooling rates, grain sizes, thermal histories, and mechanical properties remains a significant challenge during DED processing. Interpretable and data-driven modeling has proven effective in tackling this challenge, as machine learning (ML) algorithms continue to advance in capturing complex property structural relationships. However, accurately predicting the prime mechanical properties, including ultimate tensile strength (UTS), yield strength (YS), and hardness value (HV), remains a challenging task due to the complex and non-linear relationships among process …

Learning Orientation Field For Osm-Guided Autonomous Navigation, Yuming Huang, Wei Gao, Zhiyuan Zhang, Maani Ghaffari, Dezhen Song, Cheng-Zhong Xu, Hui Kong

Research Collection School Of Computing and Information Systems

OpenStreetMap (OSM) has gained popularity recently in autonomous navigation due to its public accessibility, lower maintenance costs, and broader geographical coverage. However, existing methods often struggle with noisy OSM data and incomplete sensor observations, leading to inaccuracies in trajectory planning. These challenges are particularly evident in complex driving scenarios, such as at intersections or facing occlusions. To address these challenges, we propose a robust and explainable two-stage framework to learn an Orientation Field (OrField) for robot navigation by integrating LiDAR scans and OSM routes. In the first stage, we introduce a novel representation, OrField, which can provide orientations for each …

Preference-Based Deep Reinforcement Learning For Historical Route Estimation, Boshen Pan, Yaoxin Wu, Zhiguang Cao, Yaqing Hou, Guangyu Zou, Qiang Zhang

Research Collection School Of Computing and Information Systems

Recent Deep Reinforcement Learning (DRL) techniques have advanced solutions to Vehicle Routing Problems (VRPs). However, many of these methods focus exclusively on optimizing distance-oriented objectives (i.e., minimizing route length), often overlooking the implicit drivers' preferences for routes. These preferences, which are crucial in practice, are challenging to model using traditional DRL approaches. To address this gap, we propose a preference-based DRL method characterized by its reward design and optimization objective, which is specialized to learn historical route preferences. Our experiments demonstrate that the method aligns generated solutions more closely with human preferences. Moreover, it exhibits strong generalization performance across a …

On The Chlorobenzene-Ammonia Cluster Reaction: Entrance Channel Dynamics, 2cr2pi Spectroscopy, And Ion Imaging Of The Reaction Dynamics, Ronald Mutete, Damian Kokkin, Natan Fessahaye, Thomas R. Howell, Richard A. Loomis, Scott A. Reid

Chemistry Faculty Research and Publications

Prior studies of halobenzene–ammonia complexes have shown that the nature of the cationic intermediate (i.e., Wheland-type vs ion-radical) may play a key role in determining the reaction products. To probe this link, we report here the reaction dynamics of the chlorobenzene-ammonia 1:1 complex (PhCl···NH₃) using product ion imaging following two-color resonant two-photon ionization. A threshold value of 8.863 ± 0.008 eV was determined for the appearance of protonated aniline, which accompanies Cl atom loss and is the dominant product channel at energies near threshold. Scanning down to energies close to threshold, we find no evidence for a roaming …

Wind Turbine Rotor Design Using High-Fidelity Aerostructural Optimization, Marco Mangano, Sicheng He, Yingqian Liao, Denis-Gabriel Caprace, Andrew Ning, Joaquim R. R. A. Martins

Faculty Publications

Large wind turbines yield more energy but demand careful aeroelastic blade design. Coupled multiphysics design strategies can reduce wind energy costs exploiting fluid-structure interactions. This work presents the first high-fidelity aerostructural optimization study of a large wind turbine rotor.We use blade-resolved fluid dynamics and structural solvers in a monolithic gradient-based optimization framework to explore steady-state torque and blade mass trade-offs. The coupled-adjoint approach computes gradients efficiently, enabling the optimization of over 100 structural and geometric parameters simultaneously. Our optimization study modifies a DTU 10 MW benchmark with a simplified structure and isotropic material properties. The tightly coupled optimizations increase torque …

Indigenous Women’S Reproductive Traditions: Reclaiming Sovereignty Through 500 Years Of Colonization, Stephanie A. Sellers

Gettysburg College Faculty Books

In Indigenous Women’s Reproductive Traditions, Stephanie Sellers delves into the rich history of Indigenous women’s reproductive practices before European colonization. The book highlights traditional methods such as birth control, abortion, and child spacing, which were integral to maintaining agency over their bodies. Sellers explores how these practices were disrupted by European patriarchal structures and examines the impact of forced sterilization in the 20th century. Today, Indigenous women are reclaiming their rights through movements for reproductive justice, advocating for a return to their ancestral practices and redefining concepts of womanhood and motherhood on their own tribal terms.

Neutrosophic Probabilistic And Statistical Extensions Of The Neutromultispace Model For Blended Teaching Process In University Physical Education: A Novel Neutrosophic Modeling Framework, Guoquan Lin, Hongtao Guo, Ying Zheng

Neutrosophic Sets and Systems

No abstract provided.

The Cosmoverse White Paper: Addressing Observational Tensions In Cosmology With Systematics And Fundamental Physics, Eleonora Di Valentino, Jackson Levi Said, Adam Riess, Agnieszka Pollo, Vivian Poulin, Adrià Gómez-Valent, Elena Giusarma, Et Al.

Michigan Tech Publications

The standard model of cosmology has provided a good phenomenological description of a wide range of observations both at astrophysical and cosmological scales for several decades. This concordance model is constructed by a universal cosmological constant and supported by a matter sector described by the standard model of particle physics and a cold dark matter contribution, as well as very early-time inflationary physics, and underpinned by gravitation through general relativity. There have always been open questions about the soundness of the foundations of the standard model. However, recent years have shown that there may also be questions from the observational …

A Theoretical Investigation Of Photo-Induced Deformations And Transitions In Nanoscale Ferroelectrics, Carmel Dansou

Graduate Theses and Dissertations

This dissertation presents a comprehensive first-principles investigation into the interaction of light with ferroelectric materials, focusing on light-induced structural responses (photostriction) and phase transitions in Ferroelectric superlattices, epitaxially strained BiFeO3 thin films, and twodimensional NbOX2 (X = Cl, Br, I) ferroelectrics. The work aims to provide microscopic insights into how light can control the lattice structure and even the crystallographic phase in these systems, with the broader goal of informing the design of light-responsive functional materials for practical technological applications. The first part explores light-induced effects in PbTiO3/SrTiO3 superlattices with different polarization orientations. Our simulations reveal that photoexcitation modifies the …

The Cannon-Thurston Map For Relatively Hyperbolic Free-By-Cyclic Groups, Kailey Beth Perry

Graduate Theses and Dissertations

Let F = H1 ∗ · · · ∗ Hk ∗ Fr be a splitting of a finitely generated free group, H = {H1 , . . . , Hk } a set of subgroups of F , and Φ ∈ Aut(F ) an automorphism such that for any i, Φ([Hi ]) = [Hj ] for some j. Consider the free-by-cyclic group Gϕ = ⟨F, t | t−1 xt = Φ(x)⟩. Suppose Gϕ is strongly hyperbolic relative to H̃ = {H̃1 , . . . , H̃k }, where H̃i = ⟨Hi , t | t−1 xt = Φ(x)⟩. In …

Synthesis Of Pillar[N]Arenes And Bridge-Functionalized Pillar[N]Arenes Via Cyclic And Acyclic Acetals, Babitha Machireddy

Graduate Theses and Dissertations

Pillar[n]arenes are macrocyclic compounds consisting of ‘n’ hydroquinone units linked by para-methylene bridges. Since their first report of facile synthesis 17 years ago, pillararenes have attracted significant interest due to their versatile functionality, electron-rich cavity, crystalline nature, and planar chirality. These unique properties have enabled a broad range of practical applications, including small molecule separation, formation of one-dimensional and two-dimensional channels, drug delivery systems, and enhanced emissive and fluorescent properties. The ease of synthesis of pillararenes has been one of the key factors in their widespread adoption and continued exploration in supramolecular chemistry and material science. Despite the efficiency and …

A Security Worth Having: The Pursuit Of Happiness Through Reading Burney, Radcliffe, And Austen, Samantha Meeks

Graduate Theses and Dissertations

This dissertation explores the works of three female authors of female protagonists in the long 18th century: Frances Burney’s Camilla and Evelina; Anne Radcliffe’s The Mysteries of Udolpho and The Italian; and Jane Austen’s Northanger Abbey, Sense and Sensibility, and Pride and Prejudice. By following the paths to security the female protagonists of these novels fashion, and identifying the elements of Stoicism and related Hellenism and the aspects of cybernetics, this dissertation delves into the choices female protagonists make along the way regarding their security and how such choices lead to agency and self-fashioning for these women. Emotional, economic, and …

From Structure To Specificity: Biophysical Characterization Of Functional Interfaces In Protein Systems, Logan M. Brown

Doctoral Dissertations

Proteins are nature’s dynamic molecular machines, operating across a spectrum from highly ordered scaffolds to intrinsically disordered systems, and executing functions that depend on both precise structures and conformational flexibility. Yet, the mechanistic rules linking sequence, structure, and activity particularly in disordered proteins and specialized functional adaptations remain incompletely understood. This dissertation addresses that gap by integrating structural biology, biophysics, and protein engineering to dissect molecular recognition, stability, and function across three diverse yet thematically connected protein systems. Building on this understanding of protein structure and function, the following four projects apply these concepts to address diverse biological questions, ranging …

Interpolated Factored Green's Function (Ifgf) Method Of Acceleration For Electromagnetic Scattering Off Of A Perfectly Electrically Conducting Surface, Mathew D'Amico

Doctoral Dissertations

Boundary integral equation (BIE) methods are advantageous in scattering problems due to their reduction of the problem's dimensionality as well as their automatic satisfaction of far-field radiation conditions. Specifically, for electromagnetic scattering off of perfectly electrically conducting (PEC) geometries, we are concerned with the magnetic field integral equation (MFIE). Typically, BIE implementation is iterative, with each direct integration requiring $\mathcal{O}(N^2)$ operations for a grid size $N$. For large $N$, this incurs very large computation times. To date, all existing methods that reduce the asymptotic operational complexity of evaluating the MFIE integral to $\mathcal{O}(N\log N)$ rely on use of the Fast …

Investigations Into Prior Knowledge And Self-Efficacy As Predictors Of Exam Performance In General Chemistry, And Student Interactions With Chemistry Textbooks, Gordon Hunter

Doctoral Dissertations

The first chapter addresses the validity and reliability of the Motivated Strategies for Learning Questionnaire (MSLQ) as a tool for chemistry education research. The study shows that the original MSLQ did not meet modern standards of reliability and presents a modified version that better captures self-efficacy in chemistry-specific contexts. The revised instrument shows improved model fit, reinforcing the importance of refining assessment tools for chemistry education research.The effects of prior knowledge and self-efficacy on student performance in a first-semester general chemistry course are investigated in the second chapter. Self-efficacy, defined as a learner's belief in their capability to successfully accomplish …

Psychological Factors Of Acting Talent And Success: You've Got "It", Lorelei Tierney Himlin

Doctoral Dissertations

The goal of an actor is to become invisible, bringing a character to life so convincingly that the audience forgets the actor exists outside the role. Different schools of acting often describe differing methods of portraying characters to this same general effect. To followers of the Meisner school, for example, “acting is behaving truthfully under imaginary circumstances” (Meisner et al., 1987). The “truthful” part involves creating a comprehensive mental model of a character’s imagined personality in order to fully embody that personality and extrapolate it to a situation. Then the actor uses a variety of acting techniques to think and …

Black Hole-Neutron Star Mergers: Numerical Relativity Studies Of Remnant Matter, Gravitational Waveforms, And Automated Simulation Workflows, Tia Kathleen Martineau

Doctoral Dissertations

Black hole–neutron star (BHNS) mergers are key sources for multimessenger astrophysics, offering insight into strong-field gravity and the behavior of matter at supranuclear densities. This dissertation presents three independent contributions to the study of BHNS systems using the Spectral Einstein Code (SpEC). First, a set of simulations spanning a range of mass ratios, black hole spins, and neutron star equations of state is used to map disruption thresholds and quantify remnant disk masses, unbound ejecta, and ejecta composition. These results are compared to predictions from remnant mass model FNH18, to assess its reliability in accurately predicting the resulting remnant masses …

Multi-Level Characterization And Testing Of Fatigue, Fracture And Creep Of The Ultra-High Strength Low-Alloy Steel Fabricated Via Laser Powder Bed Fusion, Nemanja Kljestan

Doctoral Dissertations

This dissertation presents a comprehensive experimental investigation of the mechanical behavior of an high-strength low-alloy (HSLA) steel fabricated via laser powder bed fusion (LPBF). The work focuses on fatigue strength, laser shock peening (LSP) effects, creep behavior, fatigue crack growth and fracture toughness. Fatigue strength was assessed using rotating bending tests, showing superior performance of LPBF specimens compared to as-cast materials due to the dual-variant martensitic microstructures. Laser shock peening enhanced fatigue life by inducing compressive residual stresses, delaying crack initiation and slowing crack propagation. Creep behavior was evaluated for different layer thicknesses, with thinner layers improving secondary creep resistance …

Simulations Of Perpendicular Electron Holes, James Patrick Mcclung

Doctoral Dissertations

Bernstein–Greene–Kruskal modes commonly manifest as electron holes and electrostatic solitary waves in space plasmas. These Debye-scale structures are nonlinear solutions to the steady-state Vlasov–Poisson system. Solutions in one dimension are highly tractable mathematically, observationally, and computationally, and are relatively well-understood. Higher-dimensional, magnetized plasmas are less amenable to study, however. Following a 20-year history of theoretical developments in two-dimensional BGK modes, this thesis presents the first high-resolution 2D and 3D simulations thereof. Stability conditions and phase-space dynamics are discovered and discussed. The simulated modes are ultimately compared to observed electron holes and modern width-amplitude relations. In addition, a significant portion of …

Computational String Theory Using Machine Learning, Giorgi Butbaia

Doctoral Dissertations

Low-energy couplings of certain superstring theories are related to the masses of the particles. One of the most promising superstring theories is $\mathcal{N}=1$ supersymmetric $E_8\times E_8$ heterotic string theory. In a certain embedding of the standard model into $E_8\times E_8$ gauge group of the heterotic string, the particle spectrum consists of $(\mathbf{27})^3$, $(\overline{\mathbf{27}})^3$, $(\mathbf{1})^3$ and $\mathbf{1}\cdot \mathbf{27}\cdot\overline{\mathbf{27}}$ couplings. While the $(\overline{\mathbf{27}})^3$ couplings are quasi-topological, the $(\mathbf{27})^3$ explicitly depend on the Ricci-flat metric on Calabi-Yau.

In this dissertation, we explore recently developed techniques for calculating the normalized Yukawa couplings on various Calabi-Yau manifolds. In Chapter 2, we describe a novel architecture, …