Digital Commons Network^™

Bayesian Network: An Explainable Artificial Intelligence (Xai) Approach To Human Performance Modelling For Control Room Operations, Houda Briwa

Theses

Alarm systems in process industry control rooms routinely exceed the performance targets set by standards such as EEMUA 191, placing operators under conditions where reliable performance is most difficult to achieve. Predicting how operators respond under such conditions is central to risk management, yet current Human Reliability Assessment (HRA) methods depend on expert judgement that is rarely tested against operational evidence, assume independence among factors known to interact, and do not explicitly represent the cognitive processes through which performance emerges. In Resilience Engineering terms, these methods encode Work-as-Imagined with limited means to assess how far expectations hold when work is …

Electromagnetic Signatures Of Massive Binary Black Hole Systems, Kaitlyn Porter

Theses

(EM) radiation, with their observable signatures shaped by the complex interplay between orbital dynamics, gas dynamics, and radiative processes. The evolution of the surrounding accretion flow is governed by general relativistic magnetohydrodynamics (GRMHD) within a strongly curved, timedependent spacetime, making the prediction of observable EM signals a challenging computational problem. This dissertation presents the development of a general relativistic ray-tracing framework that post-processes numerical relativity GRMHD simulations of accreting SMBHB systems. The framework enables the calculation of predicted images, spectra, and light curves throughout the inspiral, merger, and early post-merger phases. In parallel, improvements are made to an analytical model …

Lost In Translation: Quantifying Political Sociolect Divergence And Testing Llm Reliability As Political Interpreters, Daniel J. Corcoran

Theses

In the United States political sphere, growing polarization between Democrats and Republicans, particularly their more ideologically extreme wings, has given rise to distinct English-adjacent languages, shaped by social tendencies and referred to as “sociolects”. These sociolects offer a new avenue to analyze and further quantify growing polarization, and as Generative Artificial Intelligence (GenAI) and Large Language Models (LLMs) become increasingly embedded in political and social analysis, understanding their depth of political reasoning, biases, and classification behavior has become imperative. In this study, we sourced comment data from the CNN, Fox, and MSNBC YouTube channels, spanning from 2020 through 2024, trained …

Understanding The Long-Term Patterns Of Change Of A Tidal Marsh In Mission Bay, San Diego, California, Carrie A. Shuster, Theresa Sinicrope Talley Ph.D., Drew Talley Ph.D., Zhi-Yong Yin Ph.D., Kellie Uyeda Ph.D.

Theses

Coastal marshes are among California’s most productive ecosystems and the most impacted, having been extensively modified by dredging, filling, and urban development. This thesis investigates over a century of change for a marsh in Northern Mission Bay, San Diego, California using ecological and spatial analyses.

Chapter 1 provides an overview of the environmental history and current land use of the Northern Mission Bay marsh, tracing changes from pre-contact Indigenous stewardship through colonial and modern urban development. It also introduces a restoration plant palette derived from historical and contemporary species occurrences, ecological functions, and documented cultural uses. By integrating ethnobotanical knowledge …

Elimination Of Object Jittering Via Impostor Rendering With Gpu Emulated Doubles, James Govan Moir Iv

Theses

Object jittering is an issue that arises when rendering objects at large distances from the scene's origin. This challenge arises in software that focuses on rendering realistically scaled planetary systems and games which simulate large open world environments. While there are several techniques in common use that aim to manage jittering, they come with performance tradeoffs. We propose a new technique that combines GPU based emulated double arithmetic with impostor rendering. Our technique aims to eliminate object jittering while maintaining reasonable performance.

Accelerometer-Based Longitudinal Center Of Gravity Estimation With Lateral Acceleration Compensation, John Wynne

Theses

Spatially separated accelerometers and measured rotational motion can enable estimation of an aircraft’s longitudinal center-of-gravity (CG) location. Because the unrestricted rigid-body governing equations form an underdetermined system, the problem is reduced by assuming known lateral and vertical CG coordinates. The resulting estimator uses the lateral acceleration equation, where sensitivity to longitudinal CG is governed by the rotational excitation term 𝑀_21 = 𝑝𝑞 + 𝑟̇. Three representations of lateral acceleration at the CG are evaluated: a zero- acceleration assumption, a linear sideslip angle model, and a model based on sideslip angle and true airspeed squared. Each model is calibrated using known …

Stochastic Inverse Problems In Stochastic Elliptic And Parabolic Pdes, Zi-Jia Gong

Theses

This dissertation presents a computational framework for solving stochastic inverse problems in partial differential equations (PDEs) with random data. The objective is to recover unknown random coefficients in parabolic and elliptic diffusion equations, as well as nearly incompressible linear elasticity models. To achieve this, optimization-based approaches are used to minimize regularized Energy Least Squares (ELS) and Output Least Squares (OLS) objective functionals. Both direct and adjoint methods are used to estimate the gradient and Hessian of the objective functionals with respect to the coefficients. To avoid the expensive computation of the full Hessian matrix, the Newton-CG-like method is also adopted, …

Comparing Initial Data For Binary Neutron Star Mergers With Different Equations Of State, Aarati Nandre

Theses

Binary neutron star (BNS) mergers are an important tool for studying nuclear matter at extreme densities inaccessible to laboratory experiments. The equation of state (EOS) of this nuclear matter affects the inspiral dynamics, remnant properties, and the resulting gravitational-wave signal, but remains only weakly constrained at supranuclear densities. The observation of  GW170817 provided observational constraints on the EOS and established multimessenger astrophysics as a probe of dense matter. Simulating BNS mergers across a range of EOSs and comparing the resulting observables against detections helps narrowing this uncertainty further, and is the broader motivation for this thesis. General relativistic magnetohydrodynamic simulations …

Impact Of Chiral Chain Conformations On The Self-Assembly Of Helical Polymers, Michael J. Grant

Theses

Polymers are a soft material with diverse applications across a spectrum of technologies including, but not limited to, packaging, drug-delivery, optics, lithography and templating. This ubiquity stems from over a century of in-depth theoretical and experimental investigations relating polymer size, stiffness and architecture to their emergent material properties. Interestingly, unlike small organic molecules where solution behavior is predominantly a function of hydrophobicity, in polymers, adjusting the aforementioned features can have a dramatic impact on their interactions with neighboring molecules. In turn, this allows for a tunable parameter space enabling the ability to achieve specific engineering goals. Yet, while the impact …

Effects Of Disorder On The Magnetic And Electronic Structure Of Kagome Alloy Fe2mnsn., Thayne Dean

Theses

Iron-based magnets with the Kagome lattice are a rich set of materials due to their non-trivial topology combined with high magnetic ordering temperature (Tc). Previously, we identified and synthesized Fe2MnSn as a promising material with high magnetic anisotropy characterized by a high Tc. The desirable magnetic properties of ternary alloys are controlled by atomic-level antisite disorder and are sensitive to stoichiometry as well. To illustrate the role of disorder in Fe2MnSn, we performed DFT calculations using 64-atom supercells, which enabled us to probe changes in the density of states and magnetic moments by design. Our data show that substitution of …

Modeling Intercellular And Intracellular Organization And Dynamics Of The Bacteria Escherichia Coli : From Population Dynamics In The Gut Microbiome, To Condensate Formation In Starved Cells, Alberto Alonso

Theses

Escherichia coli is a predominantly non-pathogenic species of bacteria present in the gut of most healthy adults. It plays a critical role in the health of the gut microbiome and is also widely used as a model organism in microbiology and synthetic biology studies. This thesis discusses results from two ongoing projects on E. Coli organization and emergent biophysical properties at two very distinct length scales. The first project focuses on using genetically modified engineered E. coli bacteria for early detection and intervention in colorectal cancer (CRC), a significant public health issue in the US. The success of these engineered …

Cross-Layer Security And Responsive Evaluation Architectures For Quantum Resistance In Connected Vehicles, Geoff Twardokus

Theses

Connected vehicle (CV) technologies are emerging as a crucial technology for improving safety on future roadways. Wireless vehicle-to-everything (V2X) communication allows CVs to exchange information that provides enhanced awareness and supports better driving decisions, especially in high-risk or non-line-of-sight scenarios. However, V2X also exposes new surfaces to physical layer attacks and increasingly sophisticated, potentially quantum-capable threat actors. As human or autonomous CV drivers will make split-second safety-critical decisions based on the contents of V2X messages, ensuring their authenticity, as well as their reliable and timely delivery, is crucial. Otherwise, malicious attackers may interfere with safety services or spoof messages to …

Analysis Of Gwtc-3 With Multiple Quasicircular Next-Generationwaveform Models, Noah M. Manning

Theses

The interpretation of gravitational wave sources depends on the specific choice of model used to interpret signals. For example, previous analyses of GWTC-3 event candidates using the SEOBNRv4PHM, IMRPhenomXPHM, and NRSur7dq4 models have arrived at sometimes notably di!erent conclusions about event properties. Unfortunately, subtle analysis settings and code di!erences can also produce notable di!erences in event properties. Previous work on GWTC-3 has not yet used a consistent analysis framework to reassess all events with state-of- the-art models. In this work, we revisit GWTC-3, reassessing every event using three waveform models: two state-of-the-art models (SEOBNRv5PHM and IMRPhenomTPHM) and one older waveform …

Design And Verification Of A Reconfigurable Cryptographic Hardware Accelerator, Nicholas Merante

Theses

Cryptographic operations are used throughout computing systems to protect data confidentiality and integrity. Although software implementations provide flexibility, dedicated hardware can offer more predictable execution time and reduce the processing burden placed on a general-purpose processor. This thesis presents the design and verification of a Reconfigurable Cryptographic Hardware Accelerator (RCHA) that integrates AES-128, ChaCha20, SHA-256, and BLAKE2s within a single Verilog/SystemVerilog design. A top-level interface shared by the four cores manages algorithm selection, inputs, outputs, status, protocol errors, cycle measurement, and known-answer self-tests. Verification combined primitive-level tests, integrated UVM regressions, randomized stimulus, directed coverage tests, and OpenSSL-based C++ reference models …

Asynchronous Methods For Reducing Dynamic Power In Sparse Systems, Braley Lachner

Theses

While a strong history of computer development has maximized architecture performance, modern computing is fundamentally constrained by thermal limits and power consumption. This is especially true in power sensitive edge applications, which often have low activity. Asynchronous architectures offer a pathway to take advantage of sparsity within hardware to drastically reduce dynamic power through fine-grain selective activation of only necessary hardware. Despite these advantages, the semiconductor industry relies heavily on Electronic Design Automation (EDA) toolchains, which have been developed with many synchronous assumptions. The traditional overhead and strict incompatibility with standard EDA toolchains have limited adoption of asynchronous technologies in …

Uvm Verification Of A 4-Stage Asynchronous Risc-V Processor, Yashaswini Suresha

Theses

Functional verification often takes more effort than designing the system itself, especially when the design departs from the synchronous, globally clocked style that verification tools assume. Asynchronous or clockless circuits are an example of this. They use local request and acknowledge handshaking instead of a global clock, which reduces dynamic power and eliminates clock-distribution and skew problems. However, this also means that standard verification methods that rely on a single periodic clock no longer apply. This thesis introduces a constrained-random, coverage-driven verification environment for a four-stage asynchronous RISC-V processor. The environment is built in SystemVerilog using the Universal Verification Methodology …

Characterizing Heavy Water Displacement In Molecular Sieve Drying Beds For Practical Trace Tritium Capture Methods, Brandon M. Massett

Theses

Tritium plays a crucial role in nuclear fusion power plant designs, and adsorption beds are essential tools for managing tritiated water vapor. A series of tests was performed to investigate whether a saturated adsorption bed preferentially adsorbs heavy water vapor. The design of passive tritium control systems could potentially rely on adsorption beds preferentially trapping heavier isotopologues of water. This work investigates the displacement phenomenon and the effects of carrier gas superficial velocity on bed performance. Significant displacement was observed when a humid stream containing heavy water was diverted through a bed pre-saturated with light water, as indicated by changes …

Beyond Conventional Construction A Sustainability Assessment Of 3d-Printed Concrete For Multi-Family Housing, Jennifer Candelier

Theses

The construction industry continues to face significant challenges, including labor shortages, increasing housing demand, rising material costs, and pressure to reduce environmental impacts. Three-dimensional printed concrete (3DPC) has emerged as a potential alternative to conventional construction methods by improving automation, material efficiency, and construction productivity. However, existing research has focused primarily on single-family applications, leaving limited understanding of its feasibility for multi-family residential construction. This study evaluates whether 3D printed concrete can become a standardized construction method for multi-family residential buildings by comparing it with conventional concrete masonry unit (CMU) construction. A comparative, performance-based methodology was developed using two equivalent …

Population Inference Of Compact Binaries With Eccentricity, Muhammad Zeeshan

Theses

Gravitational waves opened a new window to study the properties of compact binary systems, providing insights into their astrophysical formation and evolution. Initially, population studies relied on mass and spin distributions to distinguish between isolated, dynamical, and hierarchical merger channels; however, orbital eccentricity offers a complementary probe of binary formation scenarios. Historically, eccentricity received limited attention due to the lack of eccentric wave- form models and the absence of strong observational evidence within the LIGO–Virgo–KAGRA sensitivity band. A growing catalog, recent advances in eccentric waveform modeling, and analyses reporting candidates consistent with non-zero eccentricity motivate a systematic population-level study with …

The Impact Of Built-Environment Walkability On Obesity Among Women In Pakistan: A Cross-Sectional Analysis Using Demographic Health Surveys (Dhs) Data, Areej Arshad

Theses

Pakistan is the fifth most populous country in the world, with a population of over 247 million people in 2023. According to the World Health Organization, 23% of Pakistan’s population is obese, with higher prevalence among women (26%) compared to men (19.9%). Recent research in high-income countries has identified built-environment as an important factor impacting physical activity, as well as health outcomes like obesity rates. However, work linking built-environment and health outcomes is scattered for low- and middle- income countries. This study, therefore, aimed to construct a consistent and simple built-environment walkability score for Pakistan using Demographic Health Surveys (DHS) …

Model-Free Sliding Mode Control On Dc Motor Modules Using Coulomb Friction Simulation, Donovan Barros

Theses

Classical control methods such as PID control are effective for simple systems where the system model is well-known and tuning can be completed without significant time and financial investment. However, systems in the modern world have become more intricate and complicated to model, which also results in more extensive tuning being required to develop effective controllers. Sliding Mode Control was developed as a more robust way to handle nonlinear systems while ensuring global asymptotic stability using Lyapunov’s stability theorem. Traditional Sliding Mode Control does still require a well-known system model, necessitating the development of a new control method. Model-Free Sliding …

Learning-Based Multi-Objective Operation Of Microgrid With Renewable Uncertainty And Demand-Side Management, Zeina Bahij

Theses

A microgrid is a small-scale power grid that can operate in either the grid-connected mode or the islanded mode. It consists of energy generation and storage devices for both power and thermal demands, where the thermal energy from the exhaust heat that cannot be transmitted over long distances can be utilized locally. The supply side may include dispatchable generation units with adjustable outputs and energy storage, alongside non-dispatchable renewables that depend entirely on resource availability. On the demand side, thermal loads are satisfied through waste heat recovery from exhaust gas (to maximize overall system efficiency) and direct fuel combustion. Electrical …

Numerical Range Of Rank-1 Partial Isometries And Elliptical Range Theorem, Lucas Saone

Theses

The Elliptical Range Theorem states that the numerical range of a 2x2 complex matrix A is an elliptical disc with foci at the eigenvalues of A and center at tr(A)/2. Many proofs have been offered for this theorem. In this paper, we provide another one. The strategy we will use is to decompose the matrix A into the sum of rank-1 operators of the form YxX*, where X and Y are in 2-D complex vectors. When analyzing the numerical range of a rank-1 operator of this form, three results can happen: i) the numerical range forms a disc at the …

Towards Reliable Large Language Models For Cyber Threat Intelligence, Md Tanvirul Alam

Theses

Cyber Threat Intelligence (CTI) helps security analysts respond to evolving threats, but the evidence it draws on is often scattered across noisy reports, advisories, and threat descriptions. Large language models (LLMs) provide a flexible interface for security analysis, yet reliable use requires grounding their outputs in source evidence, domain schemas, and CTI standards. We address this problem through structured threat representation, task-specific evaluation, and verifier-guided post-training. First, we study how unstructured CTI reports can be converted into structured threat knowledge. We develop an ontology-guided extraction framework that normalizes attack patterns, extracts typed entities and relations, and constructs a threat intelligence …

Prototyping Of A Spectropolarimetry Module For Lenslet-Based Integral Field Spectrographs, Manasa Lakshmi Narasimhan

Theses

Integral-field spectropolarimetry enables simultaneous spatial, spectral, and polarization measurements. Observations of polarized light allow researchers to map magnetic fields, distinguish scattering from intrinsic emission, and characterize the geometry of sources illuminating the large-scale dust distribution within and around galaxies. In tandem with spectral information, polarized emission can be used to detail the kinematics of dust expelled from galaxies and to probe the underlying spectrum of scattered light—measurements that help constrain key open questions such as the missing baryon problem and the role of feedback in galaxy evolution. However, spectropolarimetry is a rare capability among ground-based observatories. This thesis showcases a …

Comparing Deposition-Dependent Variations In Tungsten Oxide Thin-Film Composition Using X-Ray Photoelectron Spectroscopy, Tevfik Ozkaynak

Theses

In this work, tungsten oxide thin films were fabricated using magnetron sputter deposition and electron beam evaporation under varying oxygen conditions to produce a range of stoichiometries, including substoichiometric compositions near WO₂.₇. The primary goal was to evaluate how reliably X-ray photoelectron spectroscopy (XPS) can quantify the stoichiometry of WOₓ thin films, determine how deposition conditions influence measured composition and oxidation states, and assess how argon ion sputtering, used for surface cleaning, alters tungsten oxidation states and affects XPS based stoichiometry. The films were analyzed using XPS under ultra-high vacuum conditions. Survey spectra were used to identify elemental composition, while …

Improving Neutron Scattering And Fission Modeling With Modern Machine Learning, Karl Daningburg

Theses

We describe the development of a novel emulator for the fission fragment decay code, $\texttt{CGMF}$, which calculates the emission of prompt neutrons and $\gamma$ rays from fission fragments.  The emulator described in this work uses a combination of a noisy emission model and mixture density network to model the neutron and $\gamma$-ray multiplicities and energies.  In this manuscript, we display the power of this type of emulator for not only modeling average prompt fission observables but also correlations between fission fragment initial conditions and these observables, using both neutron-induced and spontaneous fission reactions. We find that neutron ($\gamma$-ray) multiplicities can …

Understanding The Lubrication Mechanisms Of Environmentally Compatible Protic Ionic Liquids, Davis Kipkania Kiboi

Theses

The development of environmentally sustainable lubricants is increasingly important as industries seek to reduce friction, wear, energy losses, and environmental impact. Choline amino acid protic ionic liquids (PILs) have emerged as promising candidates due to their bio-based constituents, tunable molecular structures, and favorable lubrication properties. However, the influence of amino acid structure on their lubrication mechanisms and tribological performance remains poorly understood. This dissertation investigates the physicochemical properties, tribological behavior, and tribofilm formation mechanisms of choline amino acid PILs to establish structure–property–performance relationships for sustainable lubricant design. Ten choline amino acid PILs containing glycine, alanine, lysine, leucine, isoleucine, aspartic acid, …

Analysis Of The Formation And Structure Of Protective Films In Sustainable Ionic Liquid Lubricants, Brendan Mahoney

Theses

Friction losses and wear of sliding components account for nearly one quarter of global energy consumption. Developing new lubricants to reduce these losses is essential for a more cost-effective and sustainable future. The automotive industry offers the greatest economic potential for new tribological discoveries, as it affects billions of people around the world. A significant portion of the friction losses in automobiles are due to the reciprocating motion in the engine, which leads to metal-on-metal contact. Ionic liquids have emerged as novel lubricants and additives due to their ability to form protective surface layers on metals, reducing friction and wear. …

Topological Tools For The Analysis Of Complex Networks And Higher-Order Networks, Jason P. Laruez

Theses

This dissertation investigates the intersection of topological data analysis and network science, applying and extending persistent homology, Betti numbers, and simpliciality measures to study temporal, evolving, and coevolving networked systems. We introduce a multi-layer zigzag persistent homology framework for analyzing temporal hypergraphs across multiple timescales simultaneously, and validate it on the DARPA Operationally Transparent Cyber dataset, where it produces topological signatures that distinguish malicious from benign network activity by source IP. We then apply topological tools to classical generative network models and their hypergraph extensions, characterizing how Betti numbers, filling efficiencies, and simpliciality measures evolve as these models grow or …