Physical Sciences and Mathematics Commons^™

Extended Producer Responsibility: Successes, Failures, And The Future Of Oregon Recycling, Zoe Vandal

University Honors Theses

Extended Producer Responsibility (EPR) is a waste management program used globally to improve the recovery, recycling, and management of solid waste materials. There are three types of EPR programs defined by their target materials: electronic and electrical waste (WEEE) EPR, hazardous waste EPR, and packaging EPR. Europe has implemented all three types with relative success. The US has implemented WEEE EPR and hazardous waste EPR and is currently in the process of implementing packaging EPR on a state scale in Oregon, California, Colorado, Maine, and Maryland with 10 more bills being introduced in 2024 alone. Oregon's EPR program will be …

Design And Test Of Asynchronous Systems Using The Link And Joint Model, Ebelechukwu Esimai

Dissertations and Theses

Asynchronous circuits offer numerous advantages, including low energy consumption and good composability and scalability. However, they remain meagerly adopted in the mainstream semiconductor industry. One reason is the limited number of design tools available to help designers navigate design complexity, particularly the myriad of asynchronous implementation styles.

This dissertation focuses on managing the myriad of asynchronous implementation styles by utilizing a circuit-neutral model, called Links and Joints, and embedding this Link-Joint approach into a design flow. Although years of past work have already laid the groundwork, the work in this dissertation identifies and addresses key missing pieces.

First, the …

Some Hypergeometric Identities And Related Leonard Pairs, Taiyo Summers Terada

Dissertations and Theses

The notion of a Leonard pair was introduced by Terwilliger in 2001 to simplify Leonard's theorem, which classifies the orthogonal polynomials in the terminating branch of the Askey-Wilson scheme. In the same year, Kresch and Tamvakis made a conjecture about a certain ₄F₃ hypergeometric series while studying the arithmetic analogues of the standard conjectures for the Grassmanian G(2,n). The ₄F₃ series appearing in their conjecture is closely related to a family of orthogonal polynomials in the Askey-Wilson scheme. Consequently, the theory of Leonard pairs provides a useful framework for understanding their conjecture.

In …

Atmospheric Circulation, Climate Change, And Related Impacts Over The Western United States, Graham Patrick Taylor

Dissertations and Theses

This dissertation characterizes the range of atmospheric circulation patterns and select associated meteorology impacting the northwest United States, the onset timing of rain and wind relevant to wildfire across the western United States, and how these may respond to global warming. The ability of a suite of models contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) to simulate observed large-scale atmospheric circulation patterns over the Pacific Northwest of North America is evaluated. Climate model projections of atmospheric circulation patterns, their frequency, and associated temperature and precipitation anomalies under a high-end global warming scenario are assessed over …

Computational Tools For Exploring Eigenvector Localization, Robyn Ashley Markee Reid

Dissertations and Theses

We develop computational tools for exploring eigenvector localization for a class of selfadjoint, elliptic eigenvalue problems regardless of the cause for localization. The user inputs a desired region R (not necessarily connected), a tolerance for the amount localization in R, and the desired energy range [a,b]. The tool outputs eigenvectors concentrated within the tolerance inside R and within [a, b]. We develop ample theory that justifies our algorithm, which involves a complex, compact perturbation of the operator L, Ls = L+isχR, for some (small) s > 0. Our central idea can be summarized as follows: if (λ,ψ) is an eigenpair of …

Geochemistry And Geochronology Of The Steens And Monument Dike Swarm: Implications And Relationships To Magmatic Storage And To Lava Flows Of The Picture Gorge And Steens Basalt, Rachel Anne Sweeten

Dissertations and Theses

The Columbia River Basalt Group (CRBG) is the youngest and best-preserved example of a continental flood basalt province. Vents and dikes for the four main eruptive units (Steens, Imnaha, Grande Ronde, and Picture Gorge Basalt) are the Monument, Steens and Chief Joseph Dike Swarms located in eastern Oregon, southeastern Washington, and northern Nevada.

Here we report on the compositions and timing of the dikes and sills of the Monument Dike Swarm (MDS), as well as their relationship to the subaerial lava flows of the Picture Gorge Basalt (PGB) with implications for crustal storage of these magmas. We evaluate data from …

A Deep Learning Framework For Blockage Mitigation In Mmwave Wireless, Ahmed Hazaa Almutairi

Dissertations and Theses

Millimeter-Wave (mmWave) communication is a key technology to enable next generation wireless systems. However, mmWave systems are highly susceptible to blockages, which can lead to a substantial decrease in signal strength at the receiver. Identifying blockages and mitigating them is thus a key challenge to achieve next generation wireless technology goals, such as enhanced mobile broadband (eMBB) and Ultra-Reliable and Low-Latency Communication (URLLC). This thesis proposes several deep learning (DL) frameworks for mmWave wireless blockage detection, mitigation, and duration prediction. First, we propose a DL framework to address the problem of identifying whether the mmWave wireless channel between two devices …

Optical Transport Of Ultracold Atoms, David Vera

Undergraduate Honors Theses

At temperatures near absolute zero, bosons form a macroscopic quantum state that can be manipulated and imaged in a very controlled and tunable way. To reach these extreme temperatures near absolute zero, advanced methods in cooling, including laser and evaporative cooling, must be used. In addition to these techniques for cooling, atoms must also be held up against the constant pull of gravity, so additional trapping techniques using lasers and magnets are used. In our lab at University of San Diego, we are implementing a tunable lens system (TLS) to optically transfer atoms to a more optically accessible location. A …

Using Virtual Power Plants To Advance Decarbonization And Energy Equity In California, Cheri Tsoi Yu Tse

Master's Theses

To achieve 60% renewable electricity generation by 2030 and 100% zero-carbon electricity by 2045, California must rapidly electrify and decarbonize all sectors while ensuring grid stability to avoid power outages. Virtual power plants (VPPs) are an emerging solution that can help increase the percentage of renewable energy on California’s electrical grid. This research examined how VPPs can advance decarbonization, grid stability, and energy equity in California. The report begins by clarifying the definitions and components of a VPP, finding the crucial interactions among distributed energy resources (DERs), management systems, and prosumers (energy consumers who both produce and consume electricity). Next, …

Helping The Home Cook: How Unsupervised Machine Learning Can Prevent Food Waste, Ryan B. Watson

Honors Projects

A common problem for the home cook is having too much of one food ingredient leftover, then not knowing what to do with it. To alleviate this problem, I propose using an unsupervised machine learning model to recommend recipes based on what ingredients the home cook wants to use. This model is built with FastText and trained on the recipe ingredients in the RecipeNLG dataset. Recipes are recommended based on which recipe ingredient set is most similar to the recipe ingredients provided in the user input. This solution will reduce consumer food waste by giving the home cook the information …

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

Releases Of Hazardous Materials And Waste From Transportation Incidents In The Us: An Analysis To Increase Environmental Resiliency, Elizabeth Irene Tautges

Master's Projects and Capstones

Excessive amounts of hazardous materials and waste are released into the environment from transportation incidents. The United States federal government has regulations on the movement of hazardous material and waste during transportation, but preventing environmental releases is not a major priority. Multiple external factors influence the release of hazardous material and waste into the environment. Transportation incidents can be prevented by modifying the information collected in emergency reports, adjusting transportation patterns and conditions, and expressing negative environmental impacts, preparing responder efforts to communicate effectively. The components of previous hazardous materials and waste releases emphasize the needed improvements for increasing environmental …

Evaluating The Impact Of Wildfires On Mixed Conifer Forest Regeneration And The Effectiveness Of Usfs Management Strategies On Restoring Ecosystem Services, Wyatt Farino

Master's Projects and Capstones

Wildfires are increasing in frequency, duration, and severity across Western North America. 20,438,720 acres (20.1%) of California has burned at least once since 2010. Projections suggest a statewide increase in burned area between 36% and 74% by 2085, with some forested areas in Northern California exceeding 100% in all modeled scenarios. Fire regimes have deviated far from their historical norm, significantly increasing the risk of type conversion from forest to other ecosystems. Californians rely on the myriad of ecosystem services produced by these forests to meet their basic needs. Access to these fundamental services will be severely reduced if appropriate …

Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons

Master's Projects and Capstones

The agriculture sector is responsible for 10% of the United States’ greenhouse gas emissions. In turn, anthropogenic climate change threatens crops. With its Mediterranean climate, California is the country’s largest agricultural-producing state. Many California crops are at risk due to increasing temperatures and changed precipitation patterns. This paper investigates regenerative farming techniques as a tool to protect California crops from a changing climate. Almonds are used as a case study to analyze the soil management practices, finances, and policies underlying regenerative agriculture in California. A literature review and comparative analysis are used to compare regenerative and conventional soil management practices …

U.S. International Climate Finance: An Analysis Of Historical Shortfalls And A Proposal For More Equitable Distribution, Maria-Cristina Kealey

Master's Projects and Capstones

Least-developed countries experienced 69% of deaths from climate disasters over the past 50 years despite comprising only 13% of the world’s population. Low-income and climate vulnerable nations around the world are suffering disproportionately as wealthy, high-emitting countries, such as the U.S., profit from the climate crisis. This research provides a comprehensive overview of past U.S. contributions to international climate finance efforts, assesses the climate finance deficit globally and specifically for developing countries, and proposes a more equitable share of U.S. funding from a quantitative and restorative climate justice approach. The primary analyses included quantifying the U.S. share of global greenhouse …

Supporting South Korea’S Aging Population: How Ai And Iot Acceptance Connects The Young And Old, Bobby Im

Master's Projects and Capstones

In 2024, South Korea surpassed every other nation by becoming the country with the lowest fertility rate (below 0.7%). Population decline will hinder future ability to care for their aging population and although the government and private corporations are investing millions of dollars on developing Artificial Intelligence-Internet of Things (AI-IoT) devices to support the aging, the acceptance levels and the amount of family support required is undervalued. By examining AI-IoT’s current use and role in South Korea’s public health system this paper shows how intergenerational support helps optimize existing procedures and equipment, increases the level of acceptance and use, and …

From Pixels To Plants: Remote Sensing Of California Invasive Plants, Kenneth Rangel

Master's Projects and Capstones

Invasive plants cause significant impacts to ecosystems, the economy, and human health. California has experienced significant plant invasions and is well suited to future invasion because of its Mediterranean climate and human disturbance. Eradication or control of invasive plant species requires a detailed understanding of their spatial distribution, which typically involves on the ground surveys that can be expensive or inconsistent. Remote sensing offers a potential alternative or supplement to in-person invasive plant mapping. This study performed a comparative analysis of 41 remote sensing studies that mapped the distribution of California invasive plants. I found that while high spectral resolution …

An Inventory Of Tidal Marsh Restoration Opportunities In Humboldt Bay And Their Impact On Greenhouse Gas Emissions, Nicholas Rowlands

Master's Projects and Capstones

Blue carbon ecosystems like tidal marshes, mangroves, and seagrass are efficient carbon sinks that release minimal methane under saline conditions. However, coastal wetlands globally are under threat, and on the U.S. West Coast some 85% of historic tidal wetlands have been lost. As such, there is increasing interest in their restoration as a necessary climate mitigation strategy. This GIS analysis identifies potential tidal marsh restoration sites in Humboldt Bay, California, and estimates the post-restoration greenhouse gas benefits. An elevation-based model of Humboldt Bay’s full estuary extent developed by West Coast researchers was combined with data from the California Aquatic Resources …

Elevating Urban Landscapes: How Green Roofs Enhance Biodiversity And Address Climate Change In California, Jeffrey R. Beaudoin

Master's Projects and Capstones

Green roofs are increasingly valued for mitigating the Urban Heat Island effect, providing thermal comfort amidst rising temperatures of climate change, enhancing hydrological properties, and improving urban biodiversity. In this report, I explore the environmental benefits and practical challenges of green roofs, with a specific focus on California. My study evaluates the effectiveness of green roofs in enhancing environmental sustainability using a weighted rating system. I categorize the benefits of green roofs into key areas: thermal performance, stormwater management, ecological support, mental health benefits, noise reduction, air quality improvement, and water quality enhancement. Green roofs have shown the potential for …

Non-Destructive Determination Of Surface Area In Reverse Phase Chromatographic Columns, Margaret Figus

Seton Hall University Dissertations and Theses (ETDs)

Excess adsorption isotherms of acetonitrile and methanol from water were measured on eight commercial columns. Columns used in this study represent the latest examples in column development and include three different poroshell columns (Kinotex C18, Ascentis C18, and Halo C18) as well as conventional columns with significantly different adsorbent geometries (Allure C18, YMC C18) and various hybrid-silica columns (Gemini C18, Xterra C18, and XBridge C18). Comparison of the excess adsorption isotherms measured on all these columns and expressed in surface-specific form demonstrated significant similarity of the adsorption properties of all columns, which allows the introduction of the Standard Excess Adsorption …

Optics Design And Fabrication For A Lung Interferometry-Radiography System, Rachael Lyn Blair

LSU Master's Theses

Purpose: High prevalence of lung diseases leads to many people worldwide needing spirometry and imaging testing. The typical imaging done uses chest radiography and/or low-dose CT. Lung tissue is difficult to visualize, making them substandard for monitoring lung disease progression. An improvement on these systems is x-ray interferometry which produces additional images that provide better visualization of changes in the lung tissue. The set-up of x-ray interferometry builds upon other imaging systems in that it includes diffraction gratings.

Materials: This thesis focused on implementing the fabrication processes to create diffraction gratings for a lung imager prototype that is currently under …

Decay Spectroscopy Of 134sb Using X-Array And Saturn, Graeme E. Morgan

LSU Doctoral Dissertations

The ground-state decay of ¹³⁴Sb is reported by the current evaluated nuclear data to be dominated by a 0^-→0⁺ first-forbidden Gamow-Teller transition to the ground state of ¹³⁴Te. In 2013, a recoil-ion time-of-flight (RI-TOF) spectroscopy measurement of ¹³⁴Sb with the Beta-decay Paul Trap (BPT) indicated that the ground-state feeding of ¹³⁴Te is weaker than reported. Simulation work of ¹³⁴Sb ground-state decays replicated the RI-TOF results with the addition of a theorised 5-MeV state that was fed with ~17% of the total β-decay strength. To search for higher energy states and transitions that …

H1-Conforming Finite Elements On Nonstandard Meshes, Samuel Edward Reynolds

Dissertations and Theses

We present a finite element method for linear elliptic partial differential equations on bounded planar domains that are meshed with cells that are permitted to be curvilinear and multiply connected. We employ Poisson spaces, as used in virtual element methods, consisting of globally continuous functions that locally satisfy a Poisson problem with polynomial data. This dissertation presents four peer-reviewed articles concerning both the theory and computation of using such spaces in the context of finite elements. In the first paper, we propose a Dirichlet-to-Neumann map for harmonic functions by way of computing the trace of a harmonic conjugate by numerically …

Embodied Visions: Interactive Installations That Reimagine Bodily Presence In Digital Imaging Apparatuses As Shadows, Yunzi Shi

Dartmouth College Master’s Theses

Contextualized within a history of technological development, the evolution of imaging devices and technologies is accompanied by the abstraction of spatial relationships between the body of the observer, the apparatus, and physical reality, which leads to disembodying experiences for the observing subject. Compared with devices and interactive experiences, critical reflection on the epistemological impact of digital imaging devices has less priority in computational imaging and human-computer interaction research. Taking an artistic approach, this thesis describes Embodied Visions, an exhibition featuring three interactive installations exploring the technical infrastructure for imaging and reflecting on the (dis)embodied experiences in the digital age. …

Tree Recovery By Dynamic Programming, Gustavo Alberto Gratacos

McKelvey School of Engineering Theses & Dissertations

Tree-like structures are common, naturally occurring objects that are of interest to many fields of study, such as plant science and biomedicine. Analysis of these structures is typically based on skeletons extracted from captured data, which often contain spurious segments or cycles that need to be removed. We propose a dynamic programming algorithm which seeks to recover directed trees from these noisy skeletons. Our method recovers trees by removing edges and duplicating nodes while adhering to edge-label constraints. Our algorithm proceeds by iteratively merging graph nodes, such that the solution on the original graph can be obtained from those on …

Latent Auto-Recursive Composition Engine: A Generative System For Creative Expression In Human-Ai Collaboration, Yenkai Huang

Computer Science Senior Theses

This thesis investigates the shifting boundaries of art in the era of Generative AI, crit-
ically examining the essence of art and the legitimacy of AI-generated works. Despite
significant advancements in the quality and accessibility of art through generative
AI, such creations frequently encounter skepticism regarding their status as authentic
art. To address this skepticism, the study explores the role of creative agency in var-
ious generative AI workflows and introduces an ”artist-in-the-loop” system tailored
for image generation models like Stable Diffusion. This system aims to deepen the
artist’s engagement and understanding of the creative process. Additionally, a novel
tool, …

Analysis And Computation Of Constrained Sparse Coding On Emerging Non-Von Neumann Devices, Kyle Henke

Mathematics & Statistics ETDs

This dissertation seeks to understand how different formulations of the neurally inspired Locally Competitive Algorithm (LCA) represent and solve optimization problems. By studying these networks mathematically through the lens of dynamical and gradient systems, the goal is to discern how neural computations converge and link this knowledge to theoretical neuroscience and artificial intelligence (AI). Both classical computers and advanced emerging hardware are employed in this study. The contributions of this work include:

1. Theoretical Work: A comprehensive convergence analysis for networks using both generic Rectified Linear Unit (ReLU) and Rectified Sigmoid activation functions. Exploration of techniques to address the binary …

Thermal Physiology Of Sceloporus Olivaceus And Sceloporus Variabilis In South Texas, Ian Rockel

Masters Theses

This study explores the thermal physiology of two sympatric lizard species, Sceloporus olivaceus (Texas spiny lizard) and Sceloporus variabilis (rose-bellied lizard), in South Texas. I document the metabolic rate and its temperature sensitivity, thermal limits, and performance at different temperatures to better understand the impact of rising temperatures and urbanization on these ectotherms, whose body temperature and, consequently, metabolic rate, activity level, and reproductive success depend on their thermal environment. We hypothesize that S. olivaceus will exhibit greater thermal resilience owing to its broader latitudinal range, variable habitat usage within Texas, and presumed more versatile thermoregulatory strategies. Scelorporus olivaceus's higher …

Characteristics Based Factor Models - Comparison Of Estimation Procedures, Henri Ohl

McKelvey School of Engineering Theses & Dissertations

Understanding cross-sectional and time series variation of asset returns is fundamental in finance, particularly in asset pricing. This thesis explores the integration of factor theory with machine learning to deepen our comprehension of these dynamics. Characteristics based factor models offer a systematic framework for quantifying an asset's underlying risk-return structure, leveraging time-varying conditional information on model parameters carried by firm-specific characteristics. These models serve as valuable tools for discerning the driving components of an asset's expected excess return. Recent research established a novel methodology for consistent parameter estimation within this framework, only requiring a large cross-section but not a long …

Assessing Reproducibility Of Brain-Behavior Associations Using Bootstrap Aggregation Methods, Zhetao Chen

Arts & Sciences Electronic Theses and Dissertations

在本论文中，随着越来越多地利用静息态功能连接 MRI (rs-fcMRI) 将神经活动与病理状况联系起来，我们面临着对此类数据可靠性的普遍担忧。我们的探索集中于提高人类连接组计划（HCP）数据集框架内大脑行为关联的可重复性。我们采用两种不同的引导聚合方法来研究功能连接可靠性的增强：使用循环块引导（CBB）的单独时间序列装袋和使用线性支持向量回归（LSVR）模型的主题级装袋。我们对 CBB 个体时间序列 bagging 的调查表明，这种方法并不能显着增强大脑行为关联的可重复性。这一发现指出了实现可靠的功能连接措施的复杂性以及某些聚合方法在克服这一挑战方面的局限性。相比之下，我们的学科水平考试 通过 LSVR 模型装袋呈现出更有希望的结果。这种方法显着增强了分析之间模型权重的可靠性，证明了其在提高数据稳健性和可重复性方面的功效。两种方法的这种不同影响强调了适当的分析策略在提高神经影像数据可靠性方面的关键作用。通过描述这两种方法的结果，本论文有助于对神经影像领域的数据可靠性进行更广泛的讨论。它强调了在不同数据集上持续进行方法创新和验证的必要性，以提高 rs-fcMRI 研究的可靠性和可解释性。