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2024

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Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk Jan 2024

Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk

OES Faculty Publications

Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh groundwater and circulating seawater, manifesting as submarine groundwater discharge (SGD). Water circulation induced by tidal pumping enhances the exchange of chemicals between aquifers and coastal waters and thereby influences the biogeochemistry of coastal zones. Here, we report the results of an SGD field study conducted at a steep, mega-tidal sand and gravel beach along the Canadian coast of the Bay of Fundy, a region with the world's highest tides (semi-diurnal tidal ranges exceeding 10 m). Several physical and geochemical measurement techniques were employed to document the spatiotemporal …

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Contrasting Nitrogen Dynamics Across The Mid-Atlantic Bight Shelfbreak Front: Insights From Nitrate Dual Isotopes And Nitrifier Gene Abundance, Yifan Zhu, Margaret R. Mulholland, Corday R. Selden, Dennis J. Mcgillicuddy Jr., Josie Mottram, P. Dreux Chappell, Weifang Gordon Zhang, Julie Granger, Katherine E. Crider, Meredith G. Meyer, Peter W. Bernhardt, Hilde Oliver, Sophie Clayton Jan 2024

Contrasting Nitrogen Dynamics Across The Mid-Atlantic Bight Shelfbreak Front: Insights From Nitrate Dual Isotopes And Nitrifier Gene Abundance, Yifan Zhu, Margaret R. Mulholland, Corday R. Selden, Dennis J. Mcgillicuddy Jr., Josie Mottram, P. Dreux Chappell, Weifang Gordon Zhang, Julie Granger, Katherine E. Crider, Meredith G. Meyer, Peter W. Bernhardt, Hilde Oliver, Sophie Clayton

OES Faculty Publications

Observations and model studies suggest that front dynamics can enhance phytoplankton productivity. This study tested whether frontal systems also increase the abundance of nitrifying microbes and nitrogen recycling during repeat sampling transects across the Mid‐Atlantic Bight shelfbreak in July 2019. We measured ammonium concentrations, nitrate dual isotopes (δ15N, δ18O), and ammonia monooxygenase subunit A (amoA) genes of ammonia‐oxidizing archaea (AOA) and bacteria (AOB). In subsurface shelf waters, ammonium concentrations exceeded 2 μmol L−1, due to a temporary imbalance in regeneration from sinking particles and subsequent nitrification. The inverse correlation between nitrate δ15 …

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Mapping Seagrass Distribution And Abundance: Comparing Areal Cover And Biomass Estimates Between Space-Based And Airborne Imagery, Victoria J. Hill, Richard C. Zimmerman, Dorothy A. Byron, Kenneth L. Heck Jr. Jan 2024

Mapping Seagrass Distribution And Abundance: Comparing Areal Cover And Biomass Estimates Between Space-Based And Airborne Imagery, Victoria J. Hill, Richard C. Zimmerman, Dorothy A. Byron, Kenneth L. Heck Jr.

OES Faculty Publications

This study evaluated the effectiveness of Planet satellite imagery in mapping seagrass coverage in Santa Rosa Sound, Florida. We compared very-high-resolution aerial imagery (0.3 m) collected in September 2022 with high-resolution Planet imagery (~3 m) captured during the same period. Using supervised classification techniques, we accurately identified expansive, continuous seagrass meadows in the satellite images, successfully classifying 95.5% of the 11.18 km² of seagrass area delineated manually from the aerial imagery. Our analysis utilized an occurrence frequency (OF) product, which was generated by processing ten clear-sky images collected between 8 and 25 September 2022 to determine the frequency with which …

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Submarine Groundwater Discharge As A Major Nutrient Source In River-Fed Vs. Tidally Dominated Estuaries, Stephanie J. Wilson, Joseph J. Tamborski, Bongkeun Song, Peter Bernhardt, Margaret R. Mulholland Jan 2024

Submarine Groundwater Discharge As A Major Nutrient Source In River-Fed Vs. Tidally Dominated Estuaries, Stephanie J. Wilson, Joseph J. Tamborski, Bongkeun Song, Peter Bernhardt, Margaret R. Mulholland

OES Faculty Publications

The tidal tributaries of the lower Chesapeake Bay experience seasonally recurring harmful algal blooms and the significance of submarine groundwater discharge (SGD) as a nutrient vector is largely unknown. Here, we determined seasonal SGD nutrient loads in two tributaries with contrasting hydrodynamic conditions, river-fed (York River) vs. tidally dominated (Lafayette River). Radon surveys were performed in each river to quantify SGD at the embayment-scale during spring and fall 2021. Total SGD was determined from a ²²²Rn mass balance and Monte Carlo simulations. Submarine groundwater discharge rates differed by a factor of two during spring (Lafayette = 11 ± 17 cm …

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Widespread Crab Burrows Enhance Greenhouse Gas Emissions From Coastal Blue Carbon Ecosystems, Kai Xiao, Yuchen Wu, Feng Pan, Yingrong Huang, Hebo Peng, Meiqing Lu, Yan Zhang, Hailong Li, Yan Zheng, Chunmiao Zheng, Yan Liu, Nengwan Chen, Leilei Xiao, Guangxuan Han, Yasong Li, Pei Xin, Ruili Li, Bochao Xu, Faming Wang, Joseph J. Tamborski, Alicia M. Wilson, Daniel M. Alongi, Isaac R. Santos Jan 2024

Widespread Crab Burrows Enhance Greenhouse Gas Emissions From Coastal Blue Carbon Ecosystems, Kai Xiao, Yuchen Wu, Feng Pan, Yingrong Huang, Hebo Peng, Meiqing Lu, Yan Zhang, Hailong Li, Yan Zheng, Chunmiao Zheng, Yan Liu, Nengwan Chen, Leilei Xiao, Guangxuan Han, Yasong Li, Pei Xin, Ruili Li, Bochao Xu, Faming Wang, Joseph J. Tamborski, Alicia M. Wilson, Daniel M. Alongi, Isaac R. Santos

OES Faculty Publications

Fiddler crabs, as coastal ecosystem engineers, play a crucial role in enhancing biodiversity and accelerating the flow of material and energy. Here we show how widespread crab burrows modify the carbon sequestration capacity of different habitats across a large climatic gradient. The process of crab burrowing results in the reallocation of sediment organic carbon and humus. Crab burrows can increase more greenhouse gases emissions compared to the sediment matrix (CO2: by 17-30%; CH4: by 49-141%). Straightforward calculations indicate that these increased emissions could offset 35-134% of sediment carbon burial in these two ecosystems. This research highlights the complex interactions between …

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Tracking Social Media Conversations On Extreme Weather Discussion: A Longitudinal Analysis, James Chen, Suhong Li Jan 2024

Tracking Social Media Conversations On Extreme Weather Discussion: A Longitudinal Analysis, James Chen, Suhong Li

Information Systems and Analytics Department Faculty Journal Articles

With the increasing number of extreme weather events and various disasters, people are paying more attention to environmental issues than ever, particularly global warming. Public debate on it has grown on various platforms, including newspapers and social media. This study examines emotions of the general public on global warming in the context of extreme weather events, how emotions differ by location and the change of emotion on those topics over the time. Topic modeling is used to reveal dominant topics for each type of extreme weather. The results show that discussions on Twitter predominantly focus on floods and drought/heatwaves. There …

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Beyond Selection And Practice: A Phenomenological Inquiry Into The Lived Experiences Of K-5 Literacy Curriculum Leaders In Long Island, Ny, Mary Elizabeth Pettit Jan 2024

Beyond Selection And Practice: A Phenomenological Inquiry Into The Lived Experiences Of K-5 Literacy Curriculum Leaders In Long Island, Ny, Mary Elizabeth Pettit

Theses & Dissertations

The ongoing cycle of educational reform in America has led policymakers and educational leaders to prioritize test-based results and de-prioritize noncognitive skills, equitable outcomes, and crucial socio-emotional aspects of schooling (Lynch et al., 2009). Despite the equitable goals outlined in previous education policy reforms, intended outcomes have been eclipsed by the toxic policymakers Global Education Reform Movement (GERM), which ultimately influences the curriculum selection and implementation process (Sahlburg, 2012). A literature review uncovers how inequity has been entrenched in the American education system since the 18th century, perpetuating social stratification and hindering efforts for equitable education reform. Drawing from accountability …

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Predicting Retention, Progression, And Graduation Of First-Time Freshmen Students, Brynn L. Munro, Juliann Sergi Mcbrayer, Antonio P. Gutierrez De Blume, Pamela Wells Jan 2024

Predicting Retention, Progression, And Graduation Of First-Time Freshmen Students, Brynn L. Munro, Juliann Sergi Mcbrayer, Antonio P. Gutierrez De Blume, Pamela Wells

Journal of Higher Education & Student Affairs

Currently, roughly one third of college students fit the federal government’s definition of first-generation college student status, meaning that neither parent has earned a baccalaureate degree (RTI International, 2023). This study utilized archival data at an access institution in the southeastern United States in a causal comparative study using binary logistic regression analysis to determine if first-generation college student status, gender, socioeconomic status, and academic preparedness are predictors for six-year graduation rates. Findings from this quantitative study determined that gender, socioeconomic status, and academic preparedness were significant predictors for graduation within six years of matriculation at the institution. A future …

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Efficient Privacy-Preserving Spatial Data Query In Cloud Computing, Yinbin Miao, Yutao Yang, Xinghua Li, Linfeng Wei, Zhiquan Liu, Robert H. Deng Jan 2024

Efficient Privacy-Preserving Spatial Data Query In Cloud Computing, Yinbin Miao, Yutao Yang, Xinghua Li, Linfeng Wei, Zhiquan Liu, Robert H. Deng

Research Collection School Of Computing and Information Systems

With the rapid development of geographic location technology and the explosive growth of data, a large amount of spatial data is outsourced to the cloud server for reducing the local high storage and computing burdens, but at the same time causes security issues. Thus, extensive privacy-preserving spatial data query schemes have been proposed. Most of the existing schemes use Asymmetric Scalar-Product-Preserving Encryption (ASPE) to encrypt data, but ASPE has proven to be insecure against known plaintext attack. And the existing schemes require users to provide more information about query range and thus generate a large amount of ciphertexts, which causes …

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A Unified Framework For Contextual And Factoid Question Generation, Chenhe Dong, Ying Shen, Shiyang Lin, Zhenzhou Lin, Yang Deng Jan 2024

A Unified Framework For Contextual And Factoid Question Generation, Chenhe Dong, Ying Shen, Shiyang Lin, Zhenzhou Lin, Yang Deng

Research Collection School Of Computing and Information Systems

Question generation (QG) aims to automatically generate fluent and relevant questions, where the two most mainstream directions are generating questions from unstructured contextual texts (CQG), such as news articles, and generating questions from structured factoid texts (FQG), such as knowledge graphs or tables. Existing methods for these two tasks mainly face challenges of limited internal structural information as well as scarce background information, while these two tasks can benefit each other for alleviating these issues. For example, when meeting the entity mention “United Kingdom” in CQG, it can be inferred that it is a country in European continent based on …

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Analyzing Trust In Automation Using Large Language Models, Derek Koehl Jan 2024

Analyzing Trust In Automation Using Large Language Models, Derek Koehl

Theses

This thesis explores the measurement of trust in the context of human interactions with automated systems. Trust is influenced by factors like perceived ability, benevolence, and integrity which presents a measurement challenge. Given the lack of a universally accepted model for trust, there is an abundance of trust measurement methods in the literature. This research aimed to ascertain the reliability of NLP-based measurements to determine whether such methods can shed light on the dimensionality of trust as a construct and to isolate a Linguistic Fingerprint™ of trust. The results lent support to trust as a unidimensional construct. There was little …

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The Impact Of The 2018 Camp Fire On Land-Atmosphere Interactions, Andrew C. Blackford Jan 2024

The Impact Of The 2018 Camp Fire On Land-Atmosphere Interactions, Andrew C. Blackford

Theses

Research on the effects of wildfire-induced changes in land use and land cover (LULC) on atmospheric processes is limited. This thesis presents a thorough analysis using satellite remote sensing and numerical modeling to examine how land-atmosphere interactions have been altered by the burn scar from the 2018 Camp Fire event in California. Satellite data reveals significant changes in surface characteristics affecting land-atmosphere interactions, such as land cover type, vegetation fraction (-0.12), albedo (+0.01), daytime temperature (+2.5 K), and roughness length (>-90%). Numerical modeling, based on satellite-derived LULC change scenarios, indicates notable shifts in net radiation (-0.2 MJ m-2), sensible …

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Small Molecule Modulation Of The P75 Neurotrophin Receptor Attenuates Neurodegeneration In An In Vitro Model Of Parkinson’S Disease, Poshan Pokharel Jan 2024

Small Molecule Modulation Of The P75 Neurotrophin Receptor Attenuates Neurodegeneration In An In Vitro Model Of Parkinson’S Disease, Poshan Pokharel

Theses

The p75 Neurotrophin Receptor (p75NTR) is a multifunctional transmembrane protein expressed in distinct regions of the adult nervous system. p75NTR regulates various functions, including neuronal survival or apoptosis interacting with coreceptors Trk receptors or sortilin. Activation of p75NTR occurs through proteolytic processing, and we previously demonstrated that oxidative stress induces activation of p75NTR in LUHMES cells, a neuronal cell line derived from the human ventral mesencephalon. Dopaminergic neurons of the ventral mesencephalon are vulnerable to oxidative stress and neurodegeneration associated with Parkinson’s disease (PD). Thus, we evaluated the mechanisms behind p75NTR activation and its physiological implications in a PD model. …

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Functionalizing Silicon Oxide Like Surfaces With Fatty Acids, Maman Sani Maman Brah Maman Jan 2024

Functionalizing Silicon Oxide Like Surfaces With Fatty Acids, Maman Sani Maman Brah Maman

Theses

The goal of this project was to make flat hydrophilic, silicon oxide-like surfaces hydrophobic. Using fatty acids in a wet chemistry approach. Glass, mica, and silicon wafer surfaces were cleaned with standard methods from the literature. The substrates were functionalized with oleic acid and stearic acid in ethyl alcohol. The solution concentration was held constant at 100 times a theoretical minimum concentration. The substrates were immersed at various functionalization times and various solution temperatures. Contact angle goniometer was used to measure the contact angle for water on the functionalized surfaces. The results confirmed that glass and oxidized silicon wafer surfaces …

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The Effectiveness Of Online Video-Based Training Methods, Chloe L. Wood Jan 2024

The Effectiveness Of Online Video-Based Training Methods, Chloe L. Wood

Theses

Employee training is considered critical for organization success legitimacy. The present study investigated the effects of four different online training methods on post- test recall. Student participants from UAH viewed one of four types of videos covering diversity, equity, and inclusion concepts--generative scenarios in which participants generated a label for what the scenarios covered, descriptive scenarios that included a label, a control with scenarios, and a control with no scenarios. Scenarios involved school-based and work-based examples to assess how the relevance of context for student non-workers versus student-workers impacted recall. A repeated measures ANOVA revealed that across all four conditions …

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Reduction Of Cognitive Load In Immersive Virtual Reality With Multisensory Cues, Daniel Wilson Jan 2024

Reduction Of Cognitive Load In Immersive Virtual Reality With Multisensory Cues, Daniel Wilson

Theses

This study investigated the effects of multimodal interfaces and immersive virtual environments on cognitive load. Participants played a first-person target shooting game with either a virtual reality headset or on a monitor, using visual, auditory-visual, and a haptic-visual interfaces. Performance and self-reported data about cognitive load and spatial presence were collected for each interface. The study found that both immersive environments and multimodal interfaces reduced cognitive load. Additionally, an interaction was seen such that multimodal interfaces were more effective at reducing cognitive load in immersive environments. These findings indicate that the addition of more modalities into interfaces, especially in highly …

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Quasi-Static And Dynamic Tension Testing Of As-Built And Heat-Treated Additively Manufactured 316l Stainless Steel, Terrell Elias Marler Jan 2024

Quasi-Static And Dynamic Tension Testing Of As-Built And Heat-Treated Additively Manufactured 316l Stainless Steel, Terrell Elias Marler

Theses

Additive manufacturing (AM) has several advantages over conventional subtractive manufacturing techniques, including the ability to create parts of highly complex geometries in one process thus reducing time and cost for each part. However, AM parts show different mechanical behavior compared to wrought parts due to the differences in the manufacturing processes. In particular, lack-of-fusion defects, voids, and keyhole defects can act as crack initiation sites leading to the possibility of more brittle behavior. This may be exacerbated by high rate loads, which tends to induce more brittle behavior, higher flow stress, and higher yield stress in materials. Therefore, it is …

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Spectral Deconvolution Using Machine Learning For Determining Material Compositions In Mixed Samples, Prakash Chaudhary Jan 2024

Spectral Deconvolution Using Machine Learning For Determining Material Compositions In Mixed Samples, Prakash Chaudhary

Theses

Hyperspectral unmixing is essential in determining material compositions in mixed samples with a larger number of endmembers, but achieving precise decom- position remains challenging due to the limited work done, the presence of spectral variability, and endmember complexities. This study proposes many machine learning methods and techniques to identify the material composition in mixed samples (composites). Other methods to solve this problem mainly focus on a very small number of endmembers; our approach works with many end members, improving the model’s robustness. The proposed methods effectively tackle spectral variability, high dimensionality, and the presence of similar endmembers by integrating a …

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Clearscan : A Machine Learning System For Customized, Site-Specific Radar Image Filters, Erick Jones Jan 2024

Clearscan : A Machine Learning System For Customized, Site-Specific Radar Image Filters, Erick Jones

Theses

In the field of radar meteorology, a perpetual problem is removal of so-called anomalous propagation (AP), i.e. non-precipitation echoes, from the produced images. Much work has been done in this area already, including conventional heuristic algorithms as well as machine-learning systems such as neural networks. Often the focus is on certain familiar radar architectures such as WSR-88D, also known as NEXRAD. However, a large number of radars exist which are not identical to NEXRAD; and there are also environmental differences such as RF interference which can affect the success rate of existing AP removal strategies. The focus of this paper …

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Potential Mechanisms Maintaining A Conspicuous Polymorphism In Eastern Mosquitofish (Gambusia Holbrooki), Katelyn Giltner Jan 2024

Potential Mechanisms Maintaining A Conspicuous Polymorphism In Eastern Mosquitofish (Gambusia Holbrooki), Katelyn Giltner

Theses

Genetic variation often precedes adaptation, so the mechanisms that maintain this variation are a central topic in evolutionary biology. Gambusia holbrooki, or eastern mosquitofish, possesses a rare polymorphism for melanistic coloration. Melanics and typical silver males were examined for differences in behavioral and physiological traits that may impact the persistence of the melanism trait. No differences in standard metabolic rate were found via closed-chamber respirometry, but a detour task indicated that melanic males possess greater cognitive flexibility. Effects of the social environment on stress and reproductive traits were also evaluated by pairing males and comparing cortisol levels and sperm quality …

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Aerodynamic Losses Of Additively Manufactured Blades In Transonic Conditions With Different Surface Treatments, Chase Allen Herrin Jan 2024

Aerodynamic Losses Of Additively Manufactured Blades In Transonic Conditions With Different Surface Treatments, Chase Allen Herrin

Theses

Additive manufacturing (AM) allows the production of high strength and high temperature alloys to increase the operational temperature of turbines and other engine components. AM inherently has high surface texturing, inclusive of waviness due to the layering effect in the laser powder bed fusion (L-PBF) process, and roughness due to surface defects such as partially sintered powder, deep notches, and micro-cracks. This thesis investigates how different surface treatments affect the surface static pressure variations and wake aerodynamic loss characteristics for each blade. A supersonic transonic blow down wind tunnel with a linear cascade test section is used to acquire this …

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Goes-16 Glm Optical Energy In The Inner Core Of Hurricane Ian During Two Rapid Intensification Periods, Kiahna Mollette Jan 2024

Goes-16 Glm Optical Energy In The Inner Core Of Hurricane Ian During Two Rapid Intensification Periods, Kiahna Mollette

Theses

Tropical cyclone (TC) rapid intensification (RI) is difficult to forecast but is a crucial element of TC forecasts and impacts. How lightning evolves prior to and during RI is of interest to better understanding TC RI. Results have not found a consensus in the flash rates within the inner core of rapidly intensifying TCs, indicating that there is not an understanding of these processes. Using the optical energy, measured by satellite imagery, the lightning behavior is investigated during Hurricane Ian's two RI periods, the first with almost no lightning and the second with nearly constant lightning. Radar measurements indicate that …

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Assessing The Mesoscale Variability And Rapid Tornadogenesis In The High-Shear/Low-Cape, Surging Qlcs In Northern Alabama On 01 April 2023, Joshua L. Huggins Jan 2024

Assessing The Mesoscale Variability And Rapid Tornadogenesis In The High-Shear/Low-Cape, Surging Qlcs In Northern Alabama On 01 April 2023, Joshua L. Huggins

Theses

On 01 April 2023, a severe QLCS impacted Northern Alabama during the PERiLS field campaign under High-Shear/Low-CAPE (HSLC) conditions, with CAPE below 1000 J/kg and 0-6 km wind shear exceeding 25 m/s. This study examines the mesoscale variability and tornadogenesis within the QLCS. Ceilometer and Radar Wind Profiler data indicated lowering cloud bases and shifts in the boundary layer winds. Surface analyses revealed a cold pool strength of -9◦C at the tornadogenesis location, with significant spatial variability. Storm Relative Helicity values decreased from nearly 900 to 350 m2/s2 by 0800 UTC. A lightning jump around 0756 UTC coincided with a …

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Development Of A High Speed Differential Temperature Sensor For In Situ Estimations Of Cn2 In The Planetary Boundary Layer, Michael C. Yurovchak Jan 2024

Development Of A High Speed Differential Temperature Sensor For In Situ Estimations Of Cn2 In The Planetary Boundary Layer, Michael C. Yurovchak

Theses

The propagation of electromagnetic energy through the Earth’s atmosphere is significantly modulated by spatial variability of the refractive index structure function (Cn2). In situ estimates of vertical profiles of Cn2 in the boundary layer are critical for evaluating model predictions and ground-based remote sensing retrievals of Cn2. This thesis describes the development of a sensor system that produces high frequency measurements of differential temperature between two points in space separated by a distance of 0.3m using two 5 𝜇𝑚 diameter platinum resistance temperature sensors with 10-4K resolution. The platinum wire sensors are connected to two legs of a Wheatstone Bridge …

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Grating Lobe Suppression Techniques In Sparse Linear And Planar Phased Array Antennas With Reconfigurable Phasor Elements, William M. Current Jan 2024

Grating Lobe Suppression Techniques In Sparse Linear And Planar Phased Array Antennas With Reconfigurable Phasor Elements, William M. Current

Theses

With the continual increase in the need for wireless communications, there comes a desire to decrease fabrication costs. One of the primary drivers for the cost of an antenna array is the actual number of antennas used. This number, however, can only be decreased so far for a fixed aperture area without causing undesired secondary main beams, grating lobes, to appear in the radiation pattern. This work aims to analyze the results of two methods for reducing these grating lobes in sparse, scanning phased array antennas. Both of these methods are based upon dual-mode antenna elements, as opposed to single-mode …

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Physiological Effects Of Facial Expressions During Cognitive And Social Stress, Emily X. Sorrells Jan 2024

Physiological Effects Of Facial Expressions During Cognitive And Social Stress, Emily X. Sorrells

Theses

This study explored the dynamics of facial expressions during stress. This 2 X 2 (Facial Expression by Task) mixed design evaluated how smiling and grimacing affected physiological and self-report measures of cognitive and social stress. The study implemented continuous monitoring of electrodermal activity (EDA). Facial expression was manipulated between-subjects as a genuine smile or grimace using chopsticks in the mouth. Task was manipulated as a counterbalanced within-subjects as a cognitive stressor using the Paced Auditory Serial Addition Task (PASAT) and a social stressor using Cyberball. Time was analyzed as repeated measures of change from baseline of EDA. Participants provided ratings …

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Characterization Of Thin-Walled W-24re Structures Fabricated Using Laser-Powder Bed Fusion, Madelyne Rushing Jan 2024

Characterization Of Thin-Walled W-24re Structures Fabricated Using Laser-Powder Bed Fusion, Madelyne Rushing

Theses

W-24Re is a refractory alloy used in high temperature applications due to its high melting point, recrystallization temperature, and tensile strength. Due to the high melting point, fabrication is more commonly achieved through powder metallurgy processing, which relies on diffusion. As the material is available as a powder, it is a good candidate for laser-powder bed fusion (L-PBF) processing. This study focuses on characterization of L-PBF of W-24Re thin-walled structures to determine the feasibility and primary failure mechanisms under tension compared to that of bulk W-24Re. A laser parameter set was developed, and samples were provided by Quadrus Corporation for …

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Reinforcement Learning: Applying Low Discrepancy Action Selection To Deep Deterministic Policy Gradient, Aleksandr Svishchev Jan 2024

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

College of Graduate Studies: Theses & 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. …

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The Effects Of Cultural Responsiveness And Therapy Duration On Black Americans’ Therapy Preference, Katilyn M. Ashley Treem Jan 2024

The Effects Of Cultural Responsiveness And Therapy Duration On Black Americans’ Therapy Preference, Katilyn M. Ashley Treem

College of Graduate Studies: Theses & Dissertations

Marginalized groups are less likely to seek out mental health services than non-marginalized groups. There are various reasons why marginalized groups, such as Black Americans, are less likely to seek out mental health services, one of which is the cultural barriers between a clinician and client. Research suggests that Black Americans feel that clinicians struggle to overcome these cultural barriers. Therefore, it is important for clinicians to actively receive training on how to serve clients with diverse backgrounds. Cultural responsiveness, an extension from cultural competence, is the active application of the knowledge and skills obtained in training. Examining people’s therapy …

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Applications Of Predictive And Generative Ai Algorithms: Regression Modeling, Customized Large Language Models, And Text-To-Image Generative Diffusion Models, Suhaima Jamal Jan 2024

Applications Of Predictive And Generative Ai Algorithms: Regression Modeling, Customized Large Language Models, And Text-To-Image Generative Diffusion Models, Suhaima Jamal

College of Graduate Studies: Theses & Dissertations

The integration of Machine Learning (ML) and Artificial Intelligence (AI) algorithms has radically changed predictive modeling and classification tasks, enhancing a multitude of domains with unprecedented analytical capabilities. Predictive modeling leverages ML and AI to forecast future trends or behaviors based on historical data, while classification tasks categorize data into distinct classes, from email filtering to medical diagnosis. Concurrently, text-to-image generation has emerged as a transformative potential, allowing visual content creation directly from textual descriptions. These advancements are pivotal in design, art, entertainment, and visual communication, as well as enhancing creativity and productivity. This work explores three significant studies in …

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