Digital Commons Network^™

X-Raying The Material Surrounding Active Supermassive Black Holes, Isaiah S. Cox

All Dissertations

It is important to understand the nature of the gas and dust immediately surrounding the supermassive black hole (SMBH) in active galactic nuclei (AGN), because this material feeds the accretion disk and couples the activities going on at the AGN scale to the host galaxy. However, there remain large uncertainties on basic properties about this material such as its location and distribution. This is primarily due to the difficulties in resolving spatial information on these scales at extragalactic distances.

AGN emit a tremendous amount of radiation all across the electromagnetic spectrum, including X-rays. The X-rays come from a very small …

Geography, Income, And The Incidence Of A Massachusetts Carbon Tax, Susan Stratton Sayre

Economics: Faculty Publications

I use spatial microsimulation to estimate the geographic incidence of the consumer-facing portion of various revenue-neutral carbon tax designs in Massachusetts. I identify a substantial urban-rural disparity in impacts that is reduced, but not eliminated, by proposed revenue-targeting mechanisms. I further demonstrate that seemingly small variations in the definition of rural households can have substantial impacts on urban-rural equity and the distribution of gains and losses. Proposed policies are highly progressive in the aggregate with most low-income households receiving more in rebates than they pay in taxes, but notable numbers of low-income households are likely to experience significant losses. Methodologically, …

A Climatology Of Sudden Stratospheric Warmings And Their Tropospheric Response, Joe Lovelien, Mark Sinclair

Publications

Sudden Stratospheric Warmings (SSWs) are major disruptions of the wintertime polar vortex that can significantly influence surface weather, including cold air outbreaks (CAOs) across the midlatitudes. This study presents a climatology of SSWs from 1948-2024 using NCEP-NCAR reanalysis data and examines their temporal distribution, relationships with large-scale climate variability, and impacts on surface temperatures in the United States. SSWs are identified using previously published definitions based on the reversal of zonal-mean winds at 60°N and 10 hPa. A total of 44 SSW events were identified, with a strong seasonal preference for January through March. Some decadal variability is observed, though …

Soil Property Responses To Push-Pull Cropping In East Africa, Grace Mercy Amboka, Mattias Jonsson, Celina Apel, David Meinhof, Adomas Liepa, Frank Chidawanyika, Andargachew Detebo, Felipe Librán-Embid, Emily A. Martin, Ingolf Steffan-Dewenter, Marcell K. Peters, Jie Zhang, Michael Thiel, Michael Otim, James Mugisha, Ghebremedhin Belay Bahta, Fredah Maina, Alice Murage, Benjamin Feit, A. Sigrun Dahlin

All Peer-Reviewed Publications

Push-pull technology is increasingly promoted in sub-Saharan Africa, particularly for pest management and enhancing crop productivity. However, its influence on soil properties remains understudied, despite its potential implications for soil health and sustainable soil fertility management. This study examines soil properties in push-pull and conventional non-push-pull cropping systems. Soil samples were collected from push-pull and conventional plots in Ethiopia, Kenya, Rwanda, and Uganda. We examined the associations between soil physicochemical properties and cropping systems, along with key components of push-pull, namely Desmodium coverage and plot age, and manure and mineral fertiliser application. Overall, there were a few differences in soil …

Conditioning Hierarchical Diffusion Transformers On Rf Circuit Parameters, Ethan Morton

McKelvey School of Engineering Graduate Student Theses & Dissertations

As modern ML techniques have become increasingly advanced, they have begun to be integrated into wireless RF systems for classification, identification, and spectrum management. Deep Neural Networks (DNNs) enable RF system operators and designers to design more flexible systems with greater robustness to errors and attacks. However, neural networks require significant amounts of properly annotated data to train. Current data labeling methods lack the ability to obtain reliable true labels for circuit properties such as carrier frequency offset (CFO), power amplifier (PA) non-linearity, and in-phase/quadrature (IQ) imbalance. This thesis investigates the efficacy of a novel architecture, RF-Diffusion, for generating high-quality …

Smart Medical Support System And Swin Transformer Framework For Breast Cancer Detection And Segmentation In Mammograms, Ahed Abugabah, Prashant Kumar Shukla, Piyush Kumar Shukla, Abhishek Dwivedi

All Works

Accurate and reliable breast cancer detection from mammographic images remains a critical challenge due to subtle lesion appearance, high intra-class variability, and class imbalance inherent in clinical datasets. To address these issues, this study proposes Swin-BreastNet, an explainable and optimization-driven deep learning framework for binary classification of benign and malignant breast lesions from full-field digital mammograms. The proposed approach leverages the hierarchical Swin Transformer model to effectively capture fine-grained local texture patterns and long-range contextual dependencies through Shifted Window Multi-head Self-Attention (SW-MSA). A key novelty of this work lies in the integration of Harris Hawks Optimization (HHO) for automated hyperparameter …

Public Health Responsible Ai Capability (Ph-Raic) Framework: A Conceptual Model For Integrating Ai Into Public Health Agencies, Arnob Zahid, Ravishankar Sharma, Rezwan Ahmed

All Works

Background: Artificial intelligence (AI) is transitioning from experimental pilots to core public health functions such as disease surveillance, resource planning, and analysis of social and structural determinants of health. Yet, health data collection and stewardship remain fragmented across the globe; some jurisdictions still rely on paper-based systems, while others operate noninteroperable digital systems that can exacerbate inequities. Treating health data as a global good therefore requires governance that enables innovation while protecting rights, safety, and trust. This study aims to develop a conceptual meso-level capability framework that translates responsible AI principles into organizational practices for public health agencies. Methods: We …

Assessing Geomorphic Change From Large Wood Additions In An Intensively Monitored Watershed, Alexander Walt

All Graduate Theses and Dissertations, Fall 2023 to Present

Rivers across the American West are under stress. Over time, human activities have decreased riparian vegetation and removed naturally occurring large wood from fallen trees and beaver dams. Overgrazing, wetland drainage, and artificial barriers like levees and berms have further changed these ecosystems, leaving behind simple channels that lack varied habitat for aquatic species.

Efforts to restore rivers have made some progress, but many projects are small in scale and focus more on reshaping the river rather than restoring the natural processes that keep it healthy. This study evaluates a different approach—Low-Tech Process-Based Restoration (LTPBR)—which works with nature to rebuild …

A Catalogue Of Orbital Periods Of Cataclysmic Variables And Candidates From Tess Observations, Meryem K. Dag, Simone Scaringi, Kieran O’Brien, Martina Veresvarska, Nikita Rawat, Yusuke Tampo, Santiago Hernández-Díaz, Liliana Rivera Sandoval, Wendy Mendoza, Ryan J. Oelkers, Jan Kára

Physics & Astronomy Faculty Publications

We present a systematic analysis of 2544 cataclysmic variable systems and related candidates observed by the Transiting Exoplanet Survey Satellite (TESS), with the aim of compiling a comprehensive catalogue of orbital periods. Using 2-min photometric time-series data, we applied an automated algorithm to generate Lomb–Scargle periodograms and identify the most significant coherent periodic signals, which were subsequently verified through visual inspection. This process yielded a confident sample of 910 sources exhibiting at least one periodic signal, hereafter referred to as the Cataclysmic Variable Confident Catalogue (CCC). For each object, we report the most likely orbital period together with …

A New Approach To Generate Combinatorial Patterns In Logical Analysis Of Data And Its Application To Predict College Retention, Salihah Ahmed E. Jaafari

Theses and Dissertations

Student retention and degree completion remain central challenges for higher-education institutions, with significant implications for student success, institutional effectiveness, and public accountability. While advances in predictive analytics have enabled earlier identification of students at risk of withdrawal, many commonly used machine learning approaches suffer from limited interpretability, constraining their practical usefulness for advising, intervention, and policy decision making. This dissertation addresses the problem of predicting student persistence by developing and evaluating optimization based, interpretable classification models within the Logical Analysis of Data (LAD) framework. Building on existing LAD formulations, this research introduces two novel pattern generation models, the Best Term …

Hdra-Fusion: Hybrid Detection With Routed Architecture For Manipulation-Aware Ai Face Forgery Detection, Omar Ebeid

Theses and Dissertations

With the rapid advancements in artificial intelligence-based image generation and manipulation tools, it is extremely difficult to detect if an image is genuine or artificially crafted. Despite extensive research in this area, existing image detection systems suffer from three major problems: suboptimal cross-dataset generalization due to shortcut learning of dataset-specific patterns, unreliable probability estimates due to domain shift, particularly in cross-manipulation evaluation settings, and an inability to detect images manipulated by multiple types of manipulations within a single detection framework. To address these limitations, we propose HDRA-Fusion (Hybrid Detection with Routed Architecture), a framework built on the conclusion that different …

Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante

Theses and Dissertations

This thesis presents the design and simulation of an 8-tube single-ring anti-resonant hollow-core fiber for sensing applications, with particular emphasis on methane gas detection at the fundamental absorption wavelength of 3.3 µm. Conventional solid-core silica optical fibers exhibit strong multi-phonon material absorption beyond 2.5 µm, rendering them fundamentally unsuitable for efficient light guidance and direct gas sensing at mid-infrared wavelengths. Anti-resonant hollow-core fibers overcome this limitation by guiding light predominantly through an air-filled hollow core via the anti-resonant reflecting optical waveguide mechanism, in which the thin silica glass walls of the cladding tubes act as Fabry-Pérot etalons that confine the …

Hybrid Machine Learning For Zero-Day Malware Detection: An Adaptive Static-Dynamic Analysis Approach, Garrett Farmer

Theses and Dissertations

In an era of swiftly evolving cyber threats, zero-day malware continues to be one of the most challenging classes of attacks to detect and mitigate. Traditional signature-based methods often fail to detect novel malicious code, leaving institutions vulnerable to unknown exploits. This thesis proposes a machine learning (ML)-based framework that is designed to detect unknown malware variants. By combining both static and dynamic techniques, such as file structure exam ination and sandbox-based runtime analysis, this approach aims to successfully capture malicious characteristics. The proposed custom pipeline addresses the computational overhead that is associ ated with deep inspections, outlining a staged …

Quantifying Discard Mortality Of Undersized And Ovigerous Crabs In The Gulf Of Mexico Blue Crab Fishery, Micayla Cochran

Master's Theses

Blue crabs support a valuable commercial fishery in the Gulf of Mexico. Most states require the release of undersized and ovigerous blue crabs, yet mortality of these discarded crabs is an understudied component of total mortality. The first objective of this project was to quantify discard mortality of non-target crabs using bycatch surveys across the Lake Pontchartrain–Mississippi Sound coastal system. Ovigerous crabs were most common at high salinities and temperatures, whereas undersized crab presence was inversely correlated with soak time, temperature, and the number of crabs per trap, and also varied among geographic locations. A reflex action mortality prediction assessment …

Assessment Of Mississippi Landfill Capacity In Relation To Waste Generation And Land-Use Constraints, Jason C. Anderson

Master's Theses

Municipal solid waste (MSW) management presents a growing challenge in Mississippi as population trends, socioeconomic change and regional development continue to place pressure on existing landfill capacity. This thesis examines waste generation and disposal patterns from 2000 through 2022 across Mississippi counties, with projections extending to 2050. Historical landfill tonnage data was gathered and compiled from the Mississippi Department of Environmental Quality (MDEQ) and analyzed using regression models in Excel and RStudio, with forecasts generated for both in-state and out-of-state waste flow. Results highlight significant variations among landfills, including differing closure timelines, changing county service areas and notable shifts in …

Modeling The Effects Of Low-Pressure Atmospheric Fronts On Sediment Transport Through Mississippi Sound Barrier Island Inlets, Nicholas J. Gagliano

Master's Theses

Coastal sediment dynamics in the Mississippi Sound are strongly influenced by tropical cyclones and the more frequent passage of low-pressure atmospheric fronts. While hurricanes are well recognized for reshaping barrier islands and altering sediment budgets, the cumulative role of recurrent fronts remains poorly quantified. This thesis investigates the impacts of six low-pressure atmospheric fronts (2015–2017) on sediment flux through six barrier island inlets in the Mississippi Sound.

A high-resolution application of the Regional Ocean Modeling System with the Community Sediment Transport Modeling System was developed to simulate tidal circulation, wind-driven currents, and sediment dynamics. Waves were excluded from the simulations. …

Phase Equilibria Modeling Constraints On Seismic Velocity And Density For Mafic Granulites In The Athabasca Granulite Terrane, Western Canadian Shield, Olivia Wyllie

Geosciences Undergraduate Honors Theses

Samples of mafic granulite and eclogite from the Athabasca granulite terrane, thought to be representative of the lower continental crust, were analyzed via bulk geochemistry analysis and seismically modelled with Perple_X v.7.1.6. Modeled P-wave speeds, S-wave speeds, and densities for the samples were graphed by region and calculated for wet (1.00 wt.% H2O) versus dry (0.01 wt.% H2O) conditions at 460 °C and 648 °C. The samples were found to have higher median P-wave values than those determined by Rudnick and Fountain (1995; 7.4 km/s to 7.8 km/s, as compared to 6.9 km/s to 7.2 km/s). This indicates both a …

The Impact Of Quantum Computing On Ransomware, Byron Denham

Graduate Theses and Dissertations

Ransomware is one of the most pervasive and dangerous threats to cybersecurity today. Attacks involving ransomware have been responsible for the disruption of critical services in many fields including healthcare, education, and government. In the current paradigm, crypto ransomware relies on asymmetric cryptography to perform its operations in a way that ensure the victim’s only chance for file recovery is by paying the attacker’s requested ransom payment. However, advancements in quantum computing threaten the asymmetric cryptography that ransomware relies on. It has been shown that, once developed, a sufficiently powerful quantum computer will have the ability to break asymmetric cryptography …

A Generative Ai Method For Minority Class Handling In Anomaly Detection With Drift And Explainability Analysis, Kelvin J. Mwiga, Mussa A. Dida, Ahmad Mohsin, Iqbal H. Sarker

Research outputs 2022 to 2026

Artificial Intelligence, particularly machine learning (ML) algorithms, plays a crucial role in detecting cyberattacks, including anomalies and intrusions. However, machine learning models trained on imbalanced cybersecurity datasets often struggle to accurately detect minority data instances and potential threats, thereby weakening overall system security. Despite extensive research, a persistent challenge is the inadequate explanation for model predictions concerning minority data classes. This study aims to address these limitations by developing a generative AI-based approach to manage minority classes in anomaly detection, incorporating concept drift handling and explainability analysis. We introduce an over-sampling technique, CGGReaT, designed to enhance the presence of minority …

2-D Materials: The Synthesis Of Solid-State Fuel From Metastable Diboride, Alma Kolakji

Chemistry

2-D materials are widely recognized for their anisotropic mechanical and electrical properties, surpassing their bulk counterparts. These superior characteristics of 2-D materials arise from their high surface-to-volume ratio and strong in-plane bonds. Current routes to exfoliate bulk material into 2-D nanosheets rely on weak interlayer Van der Waals forces and traditional top-down techniques. These methods are dominated by physical “force,” such as liquid-phase and mechanical exfoliation. The downside is that they apply only to weakly bonded VdW materials, limiting the variety of possible 2-D materials. To expand the variety, researchers have studied the synthesis of borophene (boron sheets). Borophene is …

Public Pool Usage As Adaptation Against Urban Heat, Stefan Borsky, Eric Fesselmeyer

Research Collection College of Integrative Studies

This paper examines the relationship between urban heat and outdoor public pool usage. Using attendance data from all 53 outdoor public pools in New York City, we analyze nonlinear effects of heat on pool usage across socioeconomic contexts. Pool attendance rises sharply with heat, especially in low-income neighborhoods where alternative coping options are likely limited. We also find that public pools reduce heat-related emergency medical service calls. Our findings highlight the need for equitable investment in blue infrastructure to enhance urban climate resilience and demonstrate how this type of adaptive infrastructure can play a critical role in managing urban heat.

Barriers To Climate Change And Sustainability Action: Nursing Education And Practice, Dawn Marie Smith

Dissertations

Climate change is one of the most pressing public health emergencies of our time and nurses can have a great impact in their current practice and in the education of future nurses (The Alliance of Nurses for Healthy Environments, n.d.; American Nurses Association, 2023; Health Care without Harm, 2025). Deaths due to rising temperatures, vector-borne illness, and food insecurity related to drought and extreme weather are on the rise (WHO, 2024). It has been estimated that globally over 250,000 additional deaths will be attributed to climate related effects between 2030 and 2050 (Watts et al., 2020; WHO, 2023).

A primary …

Enhancing Control Charting Schemes And Exploring New Assessment Metrics To Advance Quality Control And Cyber-Attack Detection In Manufacturing, Ahmad Al Majali

Dissertations

The increasing integration of digital technologies and industrial control systems in modern manufacturing has introduced new cybersecurity vulnerabilities within cyber–physical production environments. Malicious actors can exploit these vulnerabilities to induce subtle process deviations that degrade product quality while remaining undetected by conventional statistical monitoring tools. Such attacks can be deliberately engineered to manipulate process behavior through transient shifts that vary in magnitude, duration, and frequency. Despite extensive research on transient shifts caused by assignable causes in Statistical Process Control (SPC), limited attention has been given to intelligently designed cyber–physical attacks that exploit the structural characteristics and limitations of control charting …

Final Silver Bow Creek Conservation Area Materials Management Plan, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Revised Silver Bow Creek Conservation Area (Sbcca) Construction Quality Assurance Plan (Cqap), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

2024 Annual Operations And Maintenance Report 2024 Bres Annual Summary Report For Work Completed In Quadrant 4, Butte-Silver Bow Department Of Reclamation And Environmental Services

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Primitive Pythagorean Triples In Lean And Reduction Modulo Odd Prime Powers, Luke Biddle

Mathematical Sciences Undergraduate Honors Theses

Primitive Pythagorean triples (PPTs) are (a,b,c) triples that satisfy the Pythagorean theorem and share no other common factors outside of 1. This project examines these PPTs reduction modulo odd prime powers by combining proof writing and number-theoretical analysis with the process of verification and formalization in the Lean proof coding language. Using the parameterization of PPTs generated by using the unit circle with additional conditions, we investigate how these triples behave modulo  for odd primes , with emphasis on counting the number of elements in the set of PPTs (a,b,c) modulo pⁿ . By using cases based on initial …

Geothermal Gradient And Lithium Co-Generation Power Potential In Lafayette County, Arkansas, Juan Agustin Falquez

Graduate Theses and Dissertations

The Smackover formation in south Arkansas is a known reservoir for brines with high temperature and salinity. Recently, Smackover formation brines in Lafayette County, Arkansas are a target for lithium extraction. A county-wide dataset of Bottomhole Temperatures (BHT) is used to estimate a lower bound geothermal gradient of 36 C/km and a reservoir temperature of 116 C at an approximate depth of 2725 m. The high temperatures make the brines a candidate for geothermal power co-generation. Geothermal power co-generation can be achieved by implementing an Organic Rankine Cycle (ORC) power plant. The Southwest Arkansas Lithium project anticipates a total of …

Impaired Tunability Of Brain State And Motor Dysfunction In A Mouse Model Of Rett Syndrome, Victoria Kindler Norman

Graduate Theses and Dissertations

Rett syndrome (RTT) is a rare neurological disorder, caused by disrupted function of the MECP2 gene, resulting in impaired cognitive and motor functions. Previous studies suggest that although MECP2 has important functions throughout the body, the etiological origins of RTT-related dysfunction should be sought within the brain. However, it remains a mystery how neural population dynamics are altered in the RTT brain and how these alterations relate to motor dysfunction. Previous studies using an RTT mouse model point to abnormal correlations among firing rates of neurons. Here we hypothesize that such disrupted neural activity correlation could be caused by abnormal …

Age And Characteristics Of Quaternary Fluvial And Dune Deposits Along The Arkansas And Cimarron Rivers In Osage And Pawnee Counties, Oklahoma, Barry A. Duncan

Graduate Theses and Dissertations

Quaternary aeolian and fluvial deposits along the Arkansas and Cimarron Rivers in Osage and Pawnee counties of central Oklahoma, record Late Pleistocene and Holocene fluvial landscape history in the eastern Osage Plains. Sediment supply, climate variability, channel incision, and channel migration control this landscape evolution. Sediment supply of both streams is dominantly sand. Late Pleistocene and Holocene precipitation have varied with periods of drought alternating with increased precipitation and warming. The study area is near the eastern boundary of substantial aeolian activity with drought and aeolian reworking of fluvial sand more severe to the west. This study examines the sediment, …