Digital Commons Network^™

Testing And Modeling Of Nonlinearities In Riveted And Bolted Structures, Joshua E. Blackham

Theses and Dissertations

Joints are difficult to model because of various small-scale and nonlinear features, such as local geometry, preload, friction and contact. These features cause a local change in stiffness and energy dissipation which result in changes in the effective natural frequency and damping of the whole structure. Past studies have found good success using nonlinear Iwan elements as whole joint models for bolted joints in a few different structures. In Chapter 3, a similar approach is proposed for modeling riveted joints, which seeks to capture the vibrational response of a test structure including changes in the effective modal frequency and damping …

Wind Collapse Risk And Serviceability Drift Of Steel Concentrically Braced Frame Buildings, Sarah Corrinne Partington Cluff

Theses and Dissertations

Seismic design provisions use the ductility and reserve strength of the lateral structural system to reduce the loads used in design, making the structural design more economical while maintaining life safety. In contrast, current wind design provisions do not. Conventional wind design relies primarily on elastic behavior. The objective of this study is to determine a wind response modification factor for steel concentrically braced frames that could be applied to reduce wind design loads based on ductility and reserve strength, while still meeting drift requirements for serviceability of the structure. To achieve the objective, three types of ductile braced frames …

Steps Towards Effective Human-Robot Co-Manipulation Through Real-Time Modus Detection And Effects Of Stiffness Variation For Human-Soft-Robot Dyads, Shaden Moss

Theses and Dissertations

A group of individuals can coordinate very easily to carry a large or heavy object together. This act of collaborative carrying is called co-manipulation. Unlike human teammates, robots cannot easily detect and respond to the intent of human partners during co-manipulation tasks. This shortcoming can be compensated for via the physical design and the software design of robots. This work treats software design with a neural net that detects human modus (or the manner in which a team moves an object together) in real time. This work treats physical design with the use of a soft robot in human-robot co-manipulation, …

Improving Devices To Measure The Thermal Conductivity Of Molten Halide Salts, Ryan J. Ruth

Theses and Dissertations

Molten salts are of high interest for use in nuclear reactors, though their thermophysical properties are notoriously hard to measure due to the extreme conditions created by them. Significant gaps remain in thermal conductivity and heat capacity data, which this work seeks to fill by improving the Needle Probe-a modified transient hot wire probe originally used by Merritt et al to measure the thermal conductivity of FLiNaK- measuring two new salts, and exploring new materials for use with molten salts. Improvements made to the Needle Probe include automation to reduce human error, more accurate heat generation modeling, a more thorough …

Integrating Temperature-Dependent Tissue Properties Into Hifu Computational Models For Enhanced Treatment Planning, Christian Kevin Valencia Narva

Theses and Dissertations

Objective: High-intensity focused ultrasound (HIFU) is a non-invasive therapy that ablates diseased tissues with high precision. Computational simulations using the Pennes Bioheat Transfer Equation (PBTE) can guide HIFU treatment by predicting temperature distributions and thermal dose volumes. Traditional simulations assume constant thermal and acoustic properties, which may oversimplify tissue behavior. Methods: This study evaluates the impact of integrating temperature-dependent thermal properties (thermal conductivity, specific heat capacity, and perfusion) in finite-difference time-domain HIFU simulations. Three scenarios were simulated: (1) a homogeneous liver with both high- and low-power sonications, (2) a rabbit thigh muscle validated against preclinical MRTI data, and (3) an …

Reservoir Characterization And Basin Modeling Of Mesozoic Siliciclastic Strata For Sedimentary Geothermal Exploration, Iron County, Utah, Theodore L. Morgan

Theses and Dissertations

The transition zone between the Colorado Plateau and Basin and Range provinces of southwestern Utah provides excellent opportunities for future geothermal resource development. A combination of large fault-controlled extensional basins with outcrop analogs along basin margins, an elevated heat flow and thermal regime and the presence of porous and permeable sedimentary formations within extensional sedimentary basins allow for sedimentary geothermal exploration and development. Utilizing a reservoir-centered approach has the potential to dramatically expand the economic limits of geothermal plays in both established and frontier basins. This study characterizes a sedimentary geothermal system in Iron County Utah, centered on the Escalante …

Aesthetics In Instructional Design, Dennis M. West

Theses and Dissertations

This multi-article dissertation examines how aesthetics enhances instructional design to foster engaging, transformative learning experiences. Despite its potential, aesthetics is often granted a secondary status in design practice, being seen as less important than functionality. The first article explores philosopher Monroe Beardsley's five aesthetic criteria--object-directedness, felt freedom, detached affect, active discovery, and wholeness--through a theoretical literature review, proposing their application to elevate learner engagement and interest. The second article, a qualitative investigation, analyzed the Cybermatics Playable Case Study (PCS; a cybersecurity simulation) from the perspective of Beardsley's aesthetic criteria. This investigation involved four students and two designers interviewed hermeneutically over …

Data Quality And Enterprise Architecture: An Analysis Of The Awareness And Knowledge Of Data Quality Artifacts, Principles, Practices, And Application In Enterprise Architecture, Jason Alan Minton

Theses and Dissertations

Enterprise Architecture (EA) is a discipline, approach, and practice that aims to align the enterprise’s technical infrastructure, strategy, processes, and technology investments with the organization’s strategy to fulfill the mission and vision. Data quality is conformance to data specifications (Talburt, 2015, p. 192), and low data quality has significant implications for decisions and outcomes across the enterprise. Scant literature and research exist surrounding the intersection, integration, and impact of data quality within EA practices. This research examines the awareness and understanding of Enterprise Architect and Technology Architect populations regarding data quality concepts, artifacts, and tools. The research aims to answer …

Building And Understanding Cryptographic Authentication Systems, James S. Conners

Theses and Dissertations

The security and usability challenges of password-based authentication have driven ongoing research into alternative cryptographic authentication systems. This dissertation explores the design, implementation, and evaluation of authentication mechanisms that enhance security while maintaining usability. Specifically, we investigate the limitations of existing passwordless authentication systems, such as FIDO2, and propose novel solutions that improve account recovery, user mental models, and adoption rates. We introduce Let's Authenticate, a certificate-based authentication system designed to address usability and security concerns inherent in existing models. Through iterative development and empirical studies, we compare this approach against contemporary methods like passkeys and password managers. Additionally, we …

An Analysis Of The Encryption Algorithms Proposed For The Mqtt Protocol On Resource Constrained Iot Devices, John Joseph Keenan

Theses and Dissertations

As more IoT devices are used to gather data and automate devices throughout the world, more security solutions are needed to keep these devices and the data they transmit secure. Many of these devices use the MQTT protocol, which does not encrypt the transferred data by default. The TLS/SSL protocols are the standard proposed solution for encrypting this traffic, but many resource constrained IoT devices do not have enough resources to run these protocols efficiently. Because of this, many other encryption algorithms have been proposed or designed for resource constrained IoT devices running the MQTT protocol, but very limited research …

Toxiverse: An Online Comprehensive Chemical Profiling, Modeling, And Data Analysis Platform, Yitao Shen

Theses and Dissertations

Massive chemical data is now publicly available through publications and various online databases. However, most online databases only provide data unsuitable for modeling purposes and limited machine learning (ML) modeling for those data. As a public chemical toxicity evaluation tool to resolve these issues, the Toxicology Universe (ToxiVerse) portal hosts curated chemical structures and toxicological/pharmaceutical data of 26,000 compounds which can be used directly for modeling purposes. Furthermore, users can upload chemical datasets to extract all involved bioassays for compounds inside as biological profiles. ToxiVerse also features automatic QSAR modeling of uploaded datasets using multiple chemical descriptors and algorithms provided …

Social Belonging In Post-Resettlement Refugees: The Role Of Aid Organizations In The United States, Jessica Jean Byers

Theses and Dissertations

Since 1975, an estimated 3.6 million refugees have entered the United States (USA Facts, 2024). The months and even years following resettlement can be difficult and isolating for refugees. Previous research has shown that creating connections with others can enhance well-being, feelings of security, and self-reliance, all of which are especially needed for vulnerable populations such as refugees (Archambault et al., 2022; Giovanetti et al., 2022). Using the theory of social network analysis and semi-structured, in-depth interviews with aid organization leaders, this study seeks to understand the relationship between refugees and aid organizations during the post-resettlement phase. It also explores …

Contingency Management For Opioid Use Disorder Buprenorphine Treatment Engagement: 3-Month Outcomes, Shelby Renee Goodwin

Theses and Dissertations

Individuals with opioid use disorder exhibit difficulty sustaining prolonged buprenorphine treatment engagement. Contingency management (CM; incentives) may serve to increase the reinforcing value of treatment itself, but most buprenorphine CM studies delivered incentives more frequently than in typical outpatient practice. This study sought to compare CM with treatment as usual (TAU; regular clinic procedures) in visit attendance and adherence (defined as urine samples positive for buprenorphine and negative for other opioids) in new outpatients at a hospital opioid treatment clinic. Participants (46 per group) were randomized to either CM or TAU and monitored by medical record for 12 weeks; for …

Contemporary Voices Of China: Biographical Introduction Of Four Contemporary Chinese Composers And Their Chinese Language Art Songs, Xintian Xu

Theses and Dissertations

This document primarily explores the rich developmental journey of Chinese modern art songs from the early 20th century to the present. It provides an overview of the lives, compositional activities, and contributions to Chinese art songs of four contemporary composers: Zheng Qiufeng, Wang Liping, Lu Zaiyi, and Zhao Jiping. To provide more specific resources, this study includes a table of selected works by the four composers, detailing the composer, song title, poet/lyricist, vocal range, and difficulty level. This section aims to serve as a practical reference for researchers, performing artists, and music educators interested in Chinese art songs.

Building Trustable Methods For Group Recommendations: Advancing Fairness And Robustness Across Domains, Siva Likitha Valluru

Theses and Dissertations

On the internet, where the number of available choices for information is exponentially growing, there is a need to prioritize and deliver relevant results to users efficiently, on demand. Recommendation systems (RSs) address that need by searching through and filtering large amounts of dynamically generated information and providing users with recommendations tailored to them. These systems have primarily focused on (1) single-user models, where recommendations are tailored towards a specific individual, or (2) single-item models, where items are recommended based on a broader appeal to users and similarities in item metadata, in the past. In many real-world scenarios, however, recommendation …

Neural Network-Based Low-Level 3d Point Cloud Processing, Pingping Cai

Theses and Dissertations

3D computer vision is a promising research field with the potential to revolutionize future lifestyles. Among various 3D representation formats, point clouds stand out for their efficiency in depicting 3D objects using a set of coordinates, enabling advancements in fields such as autonomous driving, virtual reality, and robotics. Due to the limitations of sensor fields of view and scanning trajectories, the collected point clouds are usually sparse, noisy, and incomplete, impeding the performance of many downstream applications. Thus, the tasks of low-level point cloud processing are proposed to refine and generate dense, clean, and complete point clouds. To accomplish these …

Investigating The Influence Of Volumetric Water Content In The Upper Layer Of Soil On Embankment Factor Of Safety, Kiera Rose Hughes

Theses and Dissertations

Geohazards, including landslides and embankment failures, pose significant risks to railway infrastructure, necessitating early recognition methods for effective risk mitigation. This research explores the relationship between the volumetric water content in the upper soil layer and the embankment's factor of safety (FOS) to improve early detection and stability assessment. A parametric analysis was conducted to evaluate how variations in the soil type (shear strength and hydraulic conductivity), slope geometry (angle and height) and recharge conditions (rainfall intensity and duration) affect the FOS. Using the GeoStudio software, seepage and slope stability analyses were performed for two baseline soils, as well as …

Exploiting Structures In Reinforcement Learning: Multi-Agent Homogeneity, Euclidean Symmetry, And Natural Languages, Dingyang Chen

Theses and Dissertations

Reinforcement learning (RL) has emerged as a powerful paradigm for decision-making in complex environments. However, many RL tasks exhibit inherent structural properties—such as homogeneity, symmetry, and linguistic patterns—that are often underutilized, leading to inefficiencies in learning and generalization. This dissertation systematically exploits these structures to improve the efficiency, scalability, and robustness of RL algorithms across multi-agent and sequential decision-making settings. First, we investigate homogeneity in multi-agent systems, where agents share similar roles and objectives. By leveraging this structure, we develop communication-efficient actor-critic methods for homogeneous Markov games, enabling scalable learning with reduced coordination overhead. Second, we introduce Euclidean symmetry in …

Experimental And Numerical Analysis Of Fluidization Of Pelletized Activated Carbon Columns: Effects Of Glass Bead Retention Layer, Amin Nemati Tamar

Theses and Dissertations

In pressure swing adsorption (PSA) processes there is always a desire to process as much gas as possible in the smallest beds possible. This necessarily leads to velocities that, especially during pressure-changing steps, may exceed the adsorbent particle fluidization velocity within the bed. To prevent the possibility of bed expansion and fluidization bed retention systems are usually employed at the top of the bed in the form of dense beads, bags of the same or springs, otherwise the mechanical integrity of the adsorbent might become compromised. PSA process simulation, based on Archimedes’ force balance involving weight, buoyancy and the drag …

Augmenting Deep Learning For Efficient Nextg Wireless Communication And Sensing Systems, Hem Kanta Regmi

Theses and Dissertations

Wireless networks have become an integral aspect of our daily lives. Over the years, earlier generations of wireless networks have enabled some innovative applications, such as wireless gaming, fast internet browsing, and home automation, which were previously unattainable. However, to support emerging technologies like autonomous driving, virtual reality, telemedicine, and intelligent manufacturing, which require high data throughput and low latency, there is a need for advanced wireless networks. Legacy networks like WiFi/LTE, which operate below 6 GHz, have limited bandwidth and are insufficient to fulfill the high data throughput demands of several applications. Millimeter-wave (mmWave) networks, operating between 30 GHz …

Approaches To Teaching Music Reading To Students With Dyslexia: A Guide For Piano Teachers, Olivia Grace Bradstreet Colomaio

Theses and Dissertations

Dyslexia is the most common learning disability in the United States, affecting approximately one in five individuals. According to the DSM-V-TR, the ICD-11, and the International Dyslexia Association, dyslexia is a Specific Learning Disorder that causes issues with phonological processing, sequencing of information and information processing, word recognition, reading fluency, and other issues. Due to its prevalence, the chances of piano teachers encountering a student with dyslexia in their teaching studios is highly likely. However, there is relatively little research available for piano teachers of students with dyslexia. In the music lesson, common areas of struggle for students with dyslexia …

Tritium As A Model Tracer For Predicting Per- And Polyfluoroalkyl Exposure And Potential Ecosystem And Human Health Impacts, Erika Craig

Theses and Dissertations

For this thesis, historical tritium and per-and polyfluoroalkyl substances (PFAS) concentrations measured in surface waters of South Carolina at or near the Savannah River Site (SRS) were compared. Statistical linear regression analysis was used to assess the ability of tritium as a model tracer for predicting PFAS concentrations, specifically perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) distributions. Nine years of tritium monitoring data, (2014 – 2022), were analyzed and used in linear regressions to assess their association with PFAS levels of PFOA and PFOS measured during 2023, in and around the SRS and the adjoining Savannah River. Initially, a normality …

Reclaiming The Body: Gender Politics And Embodied Meaning In Piano Performance And Pedagogy, Rachel Misheff

Theses and Dissertations

This study examines the impact of the mind-body duality and its gendered metaphor on the lived experiences of historical and contemporary female pianists. Specifically, it explores how the principles of mind-body dualism have constructed gendered practices in piano performance and pedagogy that have both marginalized female pianists and engendered distinct embodied relationships to music. The study draws upon research from other disciplines, such as phenomenology, theories of embodiment, feminist theory, psychoanalysis, and Embodied Music Cognition, to examine how these gendered musical norms resulting from mind-body dualism functioned as forces of social inscription. This research, therefore, suggests that the body’s lived …

Multiscale Modeling Techniques For Electrodynamic Systems, Hunter Teel

Theses and Dissertations

In order to rapidly develop better electromagnetic and electrochemical systems, approaching these complicated topics from multiple perspectives is necessary. The use of mathematical models and numerical simulation offers the ability to evaluate and predict the performance of these systems based off the principles of electrodynamics in an ideal setting. Through the use of Computational Fluid Dynamics (CFD), representative geometries of scales can be created and evaluated to provide insight into the behavior of these systems. Simulation offers a modifiable environment that can approach the relevant physics from both the microscale and macroscale. Conclusions, results, boundary conditions, or other information from …

Hallucinations In Large Foundation Models: Characterization, Quantification, Detection, Avoidance, And Mitigation, Vipula Rawte

Theses and Dissertations

Deception is an inherent aspect of social interactions, with research indicating that most people engage in deceptive behavior at least once or twice daily . In parallel, advances in artificial intelligence have led to machines exhibiting deceptive tendencies. These deceptions can be categorized into two types: unintended and intentional. Unintended deceptions - often referred to as hallucinations - occur when generative AI systems produce plausible and convincing narratives yet are factually inaccurate. This phenomenon primarily results from the systems' architectural design, extensive parametric memory, and reliance on statistical assumptions. In this thesis, we provide a comprehensive discussion on the characterization, …

A Novel Geometric Modeling Kernel For Automated Fiber Placement, Rowen Burney

Theses and Dissertations

Automated Fiber Placement (AFP) is a key manufacturing technique for producing high-performance composite structures, yet existing geometric modeling frameworks lack the specialized functionality required for efficient toolpath planning and laminate optimization. This work presents Knots, a Geometric Modeling Kernel (GMK) developed specifically to address these limitations by providing a unified geometric foundation tailored for AFP. Unlike general-purpose Computer Aided Design (CAD) libraries, Knots is optimized for AFP, offering specialized geometric operations that streamline the transition from design to manufacturing. It directly manages the loading and computation of geometric data, ensuring structured laminate generation while supporting automation and scripting for improved …

Imu-Mechanized Discrete Error-State Kalman Filtering With Lie-Group Pose Representations, Daniel P. Koch

Theses and Dissertations

This dissertation investigates methodologies for consistent Kalman filtering with Lie-group based representations of the vehicle pose. Early results are centered around the relative navigation framework, which maintains filter observability and consistency by only tracking the state relative to the latest keyframe of an odometry system such as visual odometry or laser scan matching. A detailed derivation of a relative multiplicative extended Kalman filter, using a quaternion parameterization of the attitude state, is presented for application to multirotor vehicles. The remainder of the dissertation focuses on Kalman filtering using a Lie-group SE(3) pose representation, which improves filter consistency by correctly modeling …

The Confidence Trap In Pr Academia: Barriers And Solutions For Female Professors, Kailey R. Thompson

Theses and Dissertations

This study examines the career barriers female public relations professors face through the lens of Brubaker et al.'s (2025) theoretical model of "The Confidence Trap." While existing research has explored gender disparities in the PR industry, limited scholarship has investigated the challenges faced by women in PR academia. This qualitative study utilizes in-depth, semi-structured interviews with 22 female public relations professors currently on the tenure track or who have earned tenure at R1 and R2 research institutions in the United States. Thematic analysis of interview transcripts revealed that traditional barriers--such as the glass ceiling, sticky floors, maternal walls, and sexism--manifest …

Enhanced Vapour Detection Through Electrospun Metal-Oxide Nanofibers, Sri Varshini K Ms

Theses and Dissertations

The objective of this work is to fabricate metal oxide-based nanofibers, which helps in monitoring indoor air quality, which is deteriorating due to VOCs like Formaldehyde, Toluene, and Ammonia, commonly found in paints, plywood, and adhesives. Prolonged exposure to these VOCs can affect the respiratory and nervous system. They are classified as carcinogens by the IARC.

Based on the analysis, this work was framed to deposit Fe2O3, NiO, and ZnO/Fe2O3 as well ZnO/NiO and Fe2O3/NiO nanofibers on the glass substrate through horizontal electrospinning method. The obtained nanofibers are vacuum annealed at 50 ℃ for 30 mins to remove the water …

Design And Realization Of Concurrent Cryptosystem For Medical Image Privacy On Reconfigurable Hardware, Vinoth Raj R

Theses and Dissertations

The protection of medical image privacy plays a crucial role in maintaining confidentiality for the secure storage and transmission of patient’s sensitive healthcare data. Medical images are the widely used data type in the e-healthcare sector. Traditional cryptographic algorithms have limitations when applied to large-scale medical image datasets due to their high computational requirements. The primary goal of this research work is to design and implement indigenous algorithms to provide confidentiality for grayscale and color DICOM (Digital Imaging and Communications in Medicine) images through an encryption process. The research leverages the benefits of reconfigurable hardware, namely the Field-Programmable Gate Arrays …