Physical Sciences and Mathematics Commons^™

Comparative Analysis Of Surrogate Models For The Dissolution Of Spent Nuclear Fuel, Dayo Awe

Electronic Theses and Dissertations

This thesis presents a comparative analysis of surrogate models for the dissolution of spent nuclear fuel, with a focus on the use of deep learning techniques. The study explores the accuracy and efficiency of different machine learning methods in predicting the dissolution behavior of nuclear waste, and compares them to traditional modeling approaches. The results show that deep learning models can achieve high accuracy in predicting the dissolution rate, while also being computationally efficient. The study also discusses the potential applications of surrogate modeling in the field of nuclear waste management, including the optimization of waste disposal strategies and the …

Detection And Classification Of Diabetic Retinopathy Using Deep Learning Models, Aishat Olatunji

Electronic Theses and Dissertations

Healthcare analytics leverages extensive patient data for data-driven decision-making, enhancing patient care and results. Diabetic Retinopathy (DR), a complication of diabetes, stems from damage to the retina’s blood vessels. It can affect both type 1 and type 2 diabetes patients. Ophthalmologists employ retinal images for accurate DR diagnosis and severity assessment. Early detection is crucial for preserving vision and minimizing risks. In this context, we utilized a Kaggle dataset containing patient retinal images, employing Python’s versatile tools. Our research focuses on DR detection using deep learning techniques. We used a publicly available dataset to apply our proposed neural network and …

Quantifying The Relative Importance Of Boat Wakes In Fetch-Limited Environments, Abigail Maria Carswell

Electronic Theses and Dissertations

Wind waves and wave-generated currents are known to contribute to shoreline change, but there is increasing evidence that vessel-generated waves (i.e., boat wakes) may be responsible for erosion of shorelines in fetch-limited environments. Depending on vessel type and speed of operation, boat wakes have also been shown to be capable of resuspending sediment, degrading habitat, and water quality, and causing damage to shoreline infrastructure. The number of cottages and recreational boats on inland lakes has been steadily increasing in recent decades in Ontario, Canada, which has resulted in a growing perception that boat wakes are detrimental to the environment, infrastructure, …

An Soa-Based Approach Of Adaptive E-Tutoring Systems, Parth Hetalkumar Mistry

Electronic Theses and Dissertations

The educational technology landscape continually evolves, and e-tutoring systems are pivotal in modern pedagogy. Traditional e-tutoring methods often need help with adaptability and user-friendliness across various devices and platforms. To address these challenges, this research introduces a novel approach that leverages service-oriented architecture (SOA) principles, enhancing scalability and flexibility. The SOA configuration streamlines communication between system components, optimizing question delivery and response evaluation. Additionally, the research contributes adaptive interfaces that intelligently engage users based on their device configurations and preferences, offering facial, vocal, or textual interactions. These interfaces ensure a consistent and tailored learning experience across PCs, laptops, and mobile …

City Guarding With Cameras Of Bounded Field Of View, Mohammad Hashemi

Electronic Theses and Dissertations

We study two problems related to the City Guarding and the Art Gallery problems. 1. Given a city with k rectangular buildings, we prove that 3k+1 cameras of 180◦ field of view (half-sphere guards) are always sufficient to guard the free space (the ground, walls, roofs, and the sky). This answers a conjecture of Daescu and Malik (CCCG, 2020). 2. Given k orthogonally convex polygons of total m vertices in the plane, we prove that (m/2)+k+1 cameras of 180◦ field of view are always sufficient to guard the free space (avoiding all the polygons). This answers another conjecture of Daescu …

Automatic Construction Of Ontology With Public-Domain Datasets For Personalized Tutoring With Eca, Asim Jamal

Electronic Theses and Dissertations

E-tutoring systems have transformed remote learning and personalized education, offering potent tools for tailored instruction. The core of a personalized tutor lies in its robust ontology and knowledge base, working seamlessly to deliver captivating educational experiences. These two integral components collaborate to empower the tutor to discern learners’ needs, adapt content accordingly, and provide tailored guidance. This study introduces an automated approach for constructing an ontology utilizing publicly accessible datasets, aiming to enhance personalized tutoring through Embodied Conversational Agents (ECA). The objective is to improve the tutoring encounter by delivering bespoke, domain-specific knowledge to learners. The approach harnesses natural language …

Non-Hermitian Physics Achieved Via Non-Local Gilbert Damping, Trevor Joshua Macintosh

Electronic Theses and Dissertations

In this thesis, we study a simple model for a ferromagnet starting with Heisenberg exchange interaction including the effects of dissipation. Gilbert damping is consid- ered and generalized from an on-site term to include non-local damping interactions between neighbouring spins. The strength of the damping interaction between neigh- bours can be tuned individually to provide the freedom to change the parameters of the system and explore the range of possible non-Hermitian behaviours. We consider the example of a honeycomb lattice ferromagnet featuring Dirac cones and two sub- lattices and analyse the resulting spectra and eigenstates. Under periodic boundary conditions, we …

Xlnet4rec: Modeling User’S Long-Term And Short-Term Interests In E-Commerce Recommender Systems, Namarta Vij

Electronic Theses and Dissertations

In e-commerce, a sequential recommender system is often used to predict the item that the user is likely to select next. This prediction can be used to create a recommender system to assist the user in making selections. However, when the user’s interests evolve over time, it becomes challenging to make such personalized recommendations. A more accurate recommender system thus needs to effectively interpret and adapt to a user’s changing interests by considering user’s long-term and short-term interests. Many attention-based methods focus on a user’s last clicked item to learn short-term interests. However, this approach may not consistently represent the …

Construction Of Quot-Schemes, Majid Dehghani

Electronic Theses and Dissertations

The Quot Scheme is a construction representing parameter spaces for quotient objects of sheaves or coherent modules over a scheme. It encapsulates families of quotients by fixing a certain quotient's structure. The Hilbert Scheme, a specific type of Quot Scheme, focuses on parameterizing subschemes of a fixed projective space by fixing their Hilbert polynomials. After recalling the basic concepts of the theory, we explain the Grothendieck’s Quot scheme construction and its Grassmannian embedding. Then we continue to an explicit construction of Quot scheme in the case of graded modules over graded rings.

Knowledge Informed Fake News Detection Using Large Language Models, Jess Joseph Joseph Benny

Electronic Theses and Dissertations

The spread of false or misleading information as news has been a significant threat to governments, organizations and the economy for a long time. However, it has become more prevalent and influential in recent years due to the growing popularity of social media, which is now the primary source of information for more than half of the world’s population. Detecting fake news used to rely mostly on statistical and linguistic analysis of texts, but with the advancement of AI and computer-assisted writing tools, fake news authors can now deceive statistical models. Therefore, more sophisticated methods that use document representations from …

Dynamic Metal-Ligand Interactions In Semiconducting Π-Conjugated Materials, Peter Blake Joseph St Onge

Electronic Theses and Dissertations

Over the years, the development of materials has seen a vast amount of expansion into a variety of disciplines which have demonstrated usefulness in a large span of applications. One of these new and developing themes is the use of metals and ligands which are incorporated into polymers to modify their properties, which can enable different desired properties. Incorporation of metal-ligand complexes in materials chemistry has proven to be an area of rising interest, however, many of these interactions and systems remained completely unexplored. Understanding the key fundamental principles of how these materials can be changed and modified through metal-ligand …

On A Class Of James-Stein’S Estimators In High-Dimensional Data, Arash Aghaei Foroushani

Electronic Theses and Dissertations

In this thesis, we consider the estimation problem of the mean matrix of a multivariate normal distribution in high-dimensional data. Building upon the groundwork laid by Chételat and Wells (2012), we extend their method to the cases where the parameter is the mean matrix of a matrix normal distribution. In particular, we propose a novel class of James-Stein’s estimators for the mean matrix of a multivariate normal distribution with an unknown row covariance matrix and independent columns. Given a realistic assumption, we establish that our proposed estimator outperforms the classical maximum likelihood estimator (MLE) in the context of high-dimensional data. …

Adaptive Model Selection In Stock Market Prediction: A Modular And Scalable Big Data Analytics Approach, Mohammadehsan Akhavanpour

Electronic Theses and Dissertations

In today's globalized economy, financial markets are more interconnected than ever, generating vast amounts of data from thousands of sources every second. The need to accurately analyze and interpret this data is crucial for investors, analysts, and researchers alike. Traditional models for market prediction are limited by their ability to adapt to the real-time nature and 'big data' dimensions of these complex financial datasets. To address these challenges, this thesis proposes and implements a novel framework that combines Apache Kafka with a microservices framework. This framework offers a scalable, real-time solution for financial market prediction that effectively manages the 5Vs …

Quantifying Survival And Behaviour Of Hatchery-Reared Juvenile Bloater Stocked Across Bathymetric Depths In Lake Ontario, Lydia L. Paulic

Electronic Theses and Dissertations

Over 20 million native and non-native fishes are stocked into the Great Lakes annually as part of restoration initiatives and to support commercial and recreational fisheries. Bloater (Coregonus hoyi), a deep-water planktivore that was extirpated from Lake Ontario in the 1980s, has been consistently stocked in the lake since 2012 by Canadian and American natural resource agencies with the goal of producing a self-sustaining population. Previous research has highlighted challenges with stocking such as poor survival, attributed to high predation, potential maladaptive behaviour and barotrauma resulting from introducing a hatchery-reared species into a foreign environment. To address these survival challenges, …

Stimulated Raman Spectroscopy With Widely Tunable Probe Pulse For Measuring Dissolved Inorganic Phosphorus In The Great Lakes, Nathan Gregory Drouillard

Electronic Theses and Dissertations

The eutrophication of freshwater ecosystems remains a persistent global problem threatening biodiversity, drinking water, and economic interests. Among the Laurentian Great Lakes, Lake Erie is most severely impacted by eutrophication, experiencing annual harmful algal blooms that are thought to result from excess phosphate deposition into the ecosystem. Efforts to study and mitigate the effects of eutrophication require accurate monitoring of phosphate concentrations. The current method for measuring phosphate, the molybdenum blue method, suffers from signal interference. In this thesis, I recommend Raman spectroscopy as a label-free, reagent-free spectroscopic technique for accurately measuring phosphate in freshwater. I verify the Raman spectrum …

Medicinal Mushrooms: The Extraction And Analysis Of Bioactive Compounds From Hericium Erinaceus And Ganoderma Lucidum Mushrooms., Jhanielle Amanda-Kaye James

Electronic Theses and Dissertations

Medicinal mushrooms, such as Hericium erinaceus (lion's mane) and Ganoderma lucidum (reishi), have a rich history of traditional use in natural remedies, garnering attention for their bioactive compounds and nutritional benefits. Renowned for being protein-rich and low in fat, these fungi exhibit antimicrobial, anti-tumor, antioxidant, anti-diabetic, and anti-hypercholesterolemic properties attributed to their diverse bioactive components, including polysaccharides, proteins, terpenes, sterols, vitamins, polyphenols, and fatty acids. This study aimed to optimize extraction techniques, comparing maceration, ultrasound-assisted maceration, and Soxhlet extraction on fresh and dried lion's mane and reishi mushrooms. Varying solvent polarities and extraction times revealed that 8-hour extractions with dried …

Boat Wake Attenuation Through Artificial Vegetation - A Case Study From Peche Island, Jamie Kathryn Lilly

Electronic Theses and Dissertations

The use of nature-based solutions and engineering ideas has sparked interest in the value of vegetated shorelines for protecting against erosion. However, there is a lack of field data, and more research is needed to understand how effective vegetation is in reducing the impact of wind waves and boat wakes. The difference in period between wind waves and boat wakes suggests that they may be attenuated differently, requiring further study to determine the optimal management design. The purpose of this study is to quantify the ability of artificial vegetation to attenuate boat wakes and calculate the drag coefficient for model …

Impact Of Solar Radiation On Perchlorate Formation In The Atmosphere: Evidence From Ice Core Measurements, Bishnu Kunwar

Electronic Theses and Dissertations

Perchlorate, which derives from both anthropogenic and natural sources in the current environment, poses a substantial health hazard to humans as it competes with iodine uptake in the thyroid gland. Consequently, there has been considerable concern about minimizing human exposure to environmental perchlorate by restricting its release from man-made sources. However, the absence of a clear understanding regarding the respective contributions of man-made and natural sources has hindered widespread regulation efforts. A 300-year (1700–2007) Summit, Greenland ice core record from a previous study showed relatively stable perchlorate concentrations in Greenland snow prior to 1980, with some elevated perchlorate levels associated …

Enhancing Flight Delay Predictions Using Network Centrality Measures, Joseph Ajayi

Electronic Theses and Dissertations

Accurate prediction of flight delays remains a formidable challenge within the aviation industry, owing to its inherent complexity and the interconnectivity of its operations. Traditional flight prediction methods frequently utilize meteorological conditions—such as temperature, humidity, and dew point—alongside flight-specific data like departure and arrival times. However, these predictors often fall short of capturing the nuanced dynamics that lead to delays. This thesis introduces network centrality measures as novel predictors for enhancing the binary classification of flight arrival delays. Furthermore, it emphasizes the application of tree-based ensemble models, which are recognized for their superior ability to model complex relationships compared to …

Exploring The Consistency Of Flow Regimes Within And Among Ecoregions Of The Southeastern United States, Frank Paul Braun Iv

Electronic Theses and Dissertations

Human manipulation of river systems has long been a known contributor to the loss of freshwater biodiversity. By accounting for environmental causes of hydrologic variation among rivers, we can better understand how ecoregion mediates flow regimes and forecast species that may be at risk. Presumably, natural variation associated with ecoregion boundaries exerts strong influence on flow regimes, and may mediate relationships between other features (e.g., land use, dam operations) and hydrology. However, such between-ecoregion variation is poorly investigated, particularly at fine spatial and temporal scales. I characterized 10 hydrologic metrics, representing the five key dimensions of the flow regime (magnitude, …

Reinforcement Learning: Applying Low Discrepancy Action Selection To Deep Deterministic Policy Gradient, Aleksandr Svishchev

Electronic Theses and Dissertations

Reinforcement learning (RL) is a subfield of machine learning concerned with agents learning to behave optimally by interacting with an environment. One of the most important topics in RL is how the agent should explore, that is, how to choose actions in order to rate their impact on long-term reward. For example, a simple baseline strategy might be uniformly random action selection. This thesis investigates the heuristic idea that agents will learn faster if they explore by factoring the environment’s state into their decision and intentionally choose actions which are as different as possible from what they have previously observed. …

Influence Of Landscape And Nutrients On Stable Isotope Dynamics And Food Webs In A River Prior To Re-Establishing Fish Migration, Selina Al-Nazzal

Electronic Theses and Dissertations

Great Lakes tributaries are undergoing major ecosystem restoration through dam removal aimed at improving habitat connectivity. Re-establishing connectivity can have consequences for both desirable and undesirable species, especially in watersheds that risk the invasion of non-native species. To predict and evaluate the effects of reconnecting native fish habitats, I used stable isotopes of carbon (δ13C), nitrogen (δ15N), and sulphur (δ34S), spatial stream network (SSN) models and trophic niche measurements to examine the influence of land cover and nutrient concentration on the trophic ecology and distribution of stable isotopes of biofilm, macroinvertebrates, and fishes in the Boardman/Ottaway River (BOR), a tributary …

Advanced Deep Learning Multivariate Multi-Time Series Framework For A Novel Covid-19 Dataset, Swastik Bagga

Electronic Theses and Dissertations

This thesis introduces an innovative framework aimed at addressing the complexities of predicting outcomes in multivariate multi time series datasets in regression analysis. By applying this framework to a novel COVID-19 dataset, it enhances predictive analytics by providing accurate forecasts for epidemic trends at regional or provincial levels, going beyond national-level analysis. The framework incorporates advanced data preprocessing, feature selection, engineering, encoding, and model architecture, effectively capturing intricate variable interactions and temporal dependencies. This makes it a powerful tool for tackling multivariate multi time series regression challenges, offering valuable insights for informed decision-making. Predicting outcomes in such datasets is challenging …

Mitigating The Shortcomings Of Language Models: Strategies For Handling Memorization & Adversarial Attacks, Aly Kassem

Electronic Theses and Dissertations

Deep learning models have recently achieved remarkable progress in Natural Language Processing (NLP), specifically in classification, question-answering, and machine translation. However, NLP models face challenges related to security and privacy. Security-wise, even small perturbations in the input can significantly impact a model's prediction. This highlights the importance of generating natural adversarial attacks to analyze the weaknesses of NLP models and bolster their robustness through adversarial training (AT). Conversely, Large Language Models (LLMs) are trained on vast amounts of data, which may include sensitive information. If exposed, this poses a risk to personal privacy. LLMs can memorize portions of their training …

Comparative Lineament And Geomorphic Analysis Of Chaotic Terrains And Noctis Labyrinthus, Mars, Sarah A. Walton

Electronic Theses and Dissertations

Noctis Labyrinthus (NL) is an extensional trough network connecting the Tharsis rise and Valles Marineris on Mars. Chaotic terrains are a group of polygonally-fractured surface features commonly associated with subsidence due to rapid fluid loss within the subsurface. Polygonal surface patterns are seen at both sites, where geometric topographic highs are bounded by low troughs. Lineaments, topography, and geomorphology of NL and chaotic terrains were analyzed to determine tectonics and fluid influence in the formation and evolution of both sites. NL shows preferential fracture patterns associated with regional extension. Lineaments within chaotic terrains do not show cumulative preferential trends but …

Interactive Effects Of Sublethal Concentrations Of Fracking Biocides And Abandoned Mine Drainage On Amphipod Behavior, Kelly Lenhart

Electronic Theses and Dissertations

This thesis examined the sublethal effects of three pollutants, namely glutaraldehyde, 4,4-dimethyloxazolidine (DMO), and abandoned mine drainage (AMD), on amphipods. The primary objective was to investigate their combined effects on amphipods. The three pollutants, despite having the potential to combine in the environment, have not been studied to determine their potential for detrimental interactive effects which could result in unexpected environmental damage.

The research employed a series of experimental setups involving controlled exposure of amphipods to varying, putatively sublethal, concentrations of the chemicals of interest. Subsequently, effects were assessed via both behavioral and feeding assessments. To facilitate this analysis, novel …

Context-Driven Behavior: Improved Contextual Reasoning For Context-Aware Agents, Christian L. Wilson

Electronic Theses and Dissertations

Over the last three decades, a considerable amount of research has been dedicated to improving an artificial agent's ability to recognize and deal effectively with context. In this paper, I discuss a framework for a novel form of contextual reasoning. Unlike existing contextual reasoning frameworks, which allow an agent to apply its contextual knowledge after it is operating in an instance of a known context, the model I discuss allows an agent to reason about context proactively. With a proactive model, an agent forecasts the future contexts it will encounter, then takes steps to ensure its behaviors are appropriate for …

Modeling Forest Growth Using Sentinel-2-Derived Variables And Site Data, Peter G. Larson

Electronic Theses and Dissertations

Growing stock volume (GSV) is an important metric for determining economic yield, carbon sequestration and other ecosystem services. GSV has traditionally been estimated in situ by measuring individual trees in a stand. This process is slow and expensive, and, as a result, is not a viable means to estimate GSV on a large scale. It is also not feasible in places that are difficult to access and in places that do not have reliable management records. Multispectral optical sensors mounted on satellites are an important technology for monitoring forest resources because they offer the possibility of measuring forest resources quickly …

Synthesis Of Poly(Styrene-Co-Butyl Acrylate) Pickering Emulsion With Montmorillonite Nanoparticles And Its Comparison With Sodium Dodecyl Sulfate Surfactant On Affecting The Water Barrier Properties Of Coated Paper, Chidubem H. Uchefuna

Electronic Theses and Dissertations

Water-borne barrier dispersion coatings on paper have emerged as an alternative to extrusion coatings on paper due to improved recycling, high application speed, and other end of life attributes. Pigments are often added to improve the performance of dispersion coatings. The use of pigments to form a Pickering emulsion during the polymerization step for the production of a barrier coating on paper has not been discussed in the literature.

In this study, montmorillonite (MMT) pigment varied from 0-6 % pigment volume concentration (PVC) was used to synthesize dispersion coatings consisting of poly(styrene-co-butylacrylate) latex and compared with sodium dodecyl …

Elucidating The Pd Active Sites Of Bimetallic Gold-Palladium Catalysts Using Chemisorption And Titration Techniques, Andrew T. Boucher

Electronic Theses and Dissertations

A bimetallic nanoparticle catalyst combines two different metals on an oxide support, which can increase the selectivity towards useful products that may be too tightly bound to a monometallic catalyst. To explore the surface properties of such a system, we made a group of four PdAu bimetallic catalysts with varying gold mass loadings to compare with a parent Pd catalyst. The parent catalyst was synthesized using ion exchange, and gold was added to this parent Pd catalyst using incipient wetness impregnation (IWI) to create four bimetallic catalysts. All catalysts were characterized using H₂ and CO chemisorption in tandem with …