Development and Application of Novel Computer Vision and Machine Learning Techniques (open access)

Development and Application of Novel Computer Vision and Machine Learning Techniques

The following thesis proposes solutions to problems in two main areas of focus, computer vision and machine learning. Chapter 2 utilizes traditional computer vision methods implemented in a novel manner to successfully identify overlays contained in broadcast footage. The remaining chapters explore machine learning algorithms and apply them in various manners to big data, multi-channel image data, and ECG data. L1 and L2 principal component analysis (PCA) algorithms are implemented and tested against each other in Python, providing a metric for future implementations. Selected algorithms from this set are then applied in conjunction with other methods to solve three distinct problems. The first problem is that of big data error detection, where PCA is effectively paired with statistical signal processing methods to create a weighted controlled algorithm. Problem 2 is an implementation of image fusion built to detect and remove noise from multispectral satellite imagery, that performs at a high level. The final problem examines ECG medical data classification. PCA is integrated into a neural network solution that achieves a small performance degradation while requiring less then 20% of the full data size.
Date: August 2021
Creator: Depoian, Arthur Charles, II
System: The UNT Digital Library
Community First: An Ethnographic Approach to Understanding Local Perceptions of Sustainability in the Age of Neoliberalism (open access)

Community First: An Ethnographic Approach to Understanding Local Perceptions of Sustainability in the Age of Neoliberalism

This work describes ethnographic research completed in order to understand how local community members in Denton, Texas define, conceptualize, and speak about sustainability. The goal of this research is to encourage a more representative approach to sustainability initiatives within the City of Denton by uniting community ideas with local governance. Data for this study was collected through semi-structured interviews with residents, participant observation at community meetings, and quantitative survey analysis. Through the use of a Foucauldian framework for analysis, in conjunction with David Harvey's "entrepreneurial city," and work done in the field of environmental justice, this study highlights a potential link between neoliberal approaches to city governance and community perceptions of sustainability. This research concludes by calling for more representation of all community members within local sustainability initiatives, and provides several suggestions for how this can be achieved.
Date: May 2021
Creator: LeMay, Brittany Michelle
System: The UNT Digital Library

Influence of Hypoxia on Acute Lead Toxicity and Calcium Homeostasis in Early Life Stage Zebrafish (Danio rerio)

The purpose of this study was to investigate the effects of Pb and hypoxia co-exposure on Pb toxicity and Ca homeostasis in early life stage (ELS) zebrafish (Danio rerio). Previous evidence indicates that exposure of ELS zebrafish to hypoxia (~20% air saturation) reduces Ca uptake, likely through down-regulation of the apical epithelial Ca channel (ECaC). Considering that Pb and Ca are known antagonists and compete for uptake pathways, it was hypothesized that co-exposure of Pb with hypoxia would decrease Pb toxicity by reducing Pb uptake (likely mediated through a reduced number of ECaCs). However, it was shown that at 96 hpf, whole body accumulation of both Pb and Ca was lower at 40% air saturation compared to 100% and 20% air saturation. This result closely aligned with the 96h LC50 results which showed the highest mortality of zebrafish at 40% compared to the other air saturation levels. This suggests that toxicity is likely the result of exacerbated hypocalcemia at 40% air saturation due to both Pb competition for Ca binding to Ca uptake channels/transporters, such as ECaC, and potentially reduced expression of such channels/transporters in response to this level of hypoxia. Overall, it appears that ELS zebrafish respond differentially to …
Date: December 2021
Creator: Moghimi, Mehrnaz
System: The UNT Digital Library
CO2 Transport and Acid-Base Status during Fluctuations in Metabolic Status in Reptiles (open access)

CO2 Transport and Acid-Base Status during Fluctuations in Metabolic Status in Reptiles

Reptiles can often experience perturbations that greatly influence their metabolic status (e.g., temperature, exercise, digestion, and ontogeny). The most common cause of fluctuations in metabolic status in post-embryonic reptiles is arguably digestion and physical activity (which will be further referred to as exercise). The objective of this thesis is to determine the mechanisms involved in CO2 transport during digestion, determine the mechanisms that allow for the maintenance of acid-base homeostasis during digestion, and observing the effect of an understudied form of exercise in semi-aquatic reptiles on the regulation of metabolic acidosis and base deficit. This dissertation provided evidence for potentially novel and under investigated mechanisms for acid-base homeostasis (e.g., small intestine and tissue buffering capacity; Chapters 3 & 4), while also debunking a proposed hypothesis for the function of an anatomical feature that still remains a mystery to comparative physiologist (Chapter 2). This thesis is far from systematic and exhaustive in its approach, however, the work accomplished in this dissertation has become the foundation for multiple distinct paths for ecologically relevant investigations of the regulation of metabolic acidosis/alkalosis in reptiles.
Date: December 2021
Creator: Conner, Justin Lawrence
System: The UNT Digital Library