Electronic Thesis or Dissertation

This study examines the impact of uncertainty associated with Light Detection and Ranging (LiDAR) derived Digital Elevation Models (DEMs) on flood risk mapping in the North Biscayne Bay sub-watershed. A comparison of flood extent and generation of the probability of flooding was carried out using the bathtub and probabilistic approaches respectively. The water level was computed separately for original and refined DEM using Cascade 2001 hydrological model. Using land cover based corrected DEMs reveals a 12% reduction in flooded areas in contrast to original DEM, considering uncertainties associated with land cover. Probabilistic flood modeling via Gaussian Geostatistical Simulation accounts for DEM uncertainty, yielding nuanced probability flood risk maps (0-100%). Findings emphasize DEM refinement before conducting flood mapping to address uncertainties. Future research should explore other mediums of correction incorporating effects of point density of LiDAR, methods of DEM generation, use of diverse scenarios, and kriging techniques for flood modeling and mapping while using LiDAR derived DEM.

The link between organizational theory and its application in practice is explored in this research through the lens of Peircian semiotics. An investigation is conducted of how organizations convey their culture through mission and vision statements and the reflection of these statements within New Institutionalism. Through the use of a novel computational model that merges quantitative analysis with traditional qualitative methods, this study evaluates the relevance and effectiveness of institutional theories. The three main schools of New Institutionalism—rational choice, historical, and sociological institutionalism —are examined to determine how well municipal mission and vision statements align with the theories' principles. The analysis interprets organizational communications identifying similarities or differences between theoretical concepts and the expressions of found organizational culture. The findings produced by the analyses offer insights into the relationship between theory and practice. It highlights the challenges in interpreting the intended meanings behind organizational communications, as well as, the practical utility of theoretical models for organizational behavior. This study contributes to the organizational theory library by introducing a new methodological approach to examine and compare institutional theories and the communicative strategies.

The aim of this dissertation is to achieve a thorough understanding and develop an algorithmic framework for a crucial aspect of autonomous and artificial intelligence (AI) systems: Data Analysis. In the current era of AI and machine learning (ML), ”data” holds paramount importance. For effective learning tasks, it is essential to ensure that the training dataset is accurate and comprehensive. Additionally, during system operation, it is vital to identify and address faulty data to prevent potentially catastrophic system failures. Our research in data analysis focuses on creating new mathematical theories and algorithms for outlier-resistant matrix decomposition using L1-norm principal component analysis (PCA). L1-norm PCA has demonstrated robustness against irregular data points and will be pivotal for future AI learning and autonomous system operations.
This dissertation presents a comprehensive exploration of L1-norm techniques and their diverse applications. A summary of our contributions in this manuscript follows: Chapter 1 establishes the foundational mathematical notation and linear algebra concepts critical for the subsequent discussions, along with a review of the complexities of the current state-of-the-art in L1-norm matrix decomposition algorithms. In Chapter 2, we address the L1-norm error decomposition problem by introducing a novel method called ”Individual L1-norm-error Principal Component Computation by 3-layer Perceptron” (Perceptron L1 error). Extensive studies demonstrate the efficiency of this greedy L1-norm PC calculator.

Social media’s role in daily life is on the rise, but as social media use increases, so do questions about its potential benefits or harms. This set of studies examined the relationship between social media use, wellbeing, and perceived network responsiveness, a measure of an individual’s perception about the degree to which their online social networks are caring, validating, and understanding. Two pre-registered correlational studies which employed surveys of undergraduate students (Study 1a: N = 218, Study 1b: N = 179) found that perceived network responsiveness was positively correlated with life satisfaction and negatively correlated with loneliness. A pre-registered experimental study was also conducted in which young adults recruited from a crowdsourcing platform (N = 236) were randomly assigned to either reduce social media use to ten minutes per platform per day or to continue their normal use for one week. Participants completed nine surveys (an initial survey, seven daily surveys, and one follow-up survey) about their wellbeing, perceived network responsiveness, and social media use. The results of the initial survey also showed that perceived network responsiveness was positively correlated with life satisfaction and negatively correlated with loneliness. Contrary to predictions, the relationship between experimentally manipulated social media use and change in wellbeing outcomes (i.e., life satisfaction and loneliness) was not significantly moderated by perceived network responsiveness. Additionally, there were no significant differences between conditions with regard to wellbeing outcomes. Overall, these studies demonstrated an association between perceived network responsiveness and wellbeing while underscoring the need for focus on the more social aspects of social media use.

I examine the relationship between environmental regulation stringency and the extent of voluntary environmental disclosures by firms. The study draws on theoretical frameworks including legitimacy theory, stakeholder theory, and information asymmetry, to explore how different mechanisms influence firm behavior in the context of environmental transparency.
My empirical analysis shows a positive relationship between the stringency of environmental regulations and the level of voluntary environmental disclosures. This relationship is weakened by factors such as board independence and institutional ownership. I further confirm the positive effect of national level of environmental regulation stringency on the environmental voluntary disclosure. However, I fail to find supporting evidence on the positive moderating role of national level of environmental regulation stringency and corporate governance. In contrast, I find evidence that external institutional ownership and independent directors, who represent interests of external blockholders, have a preventive and monitoring effect on the main relationship to reduce the threat of misleading voluntary information and proprietary cost.

This thesis examines the völur, arguing that these mythic figures actually encompass a broader range of Nordic women than are typically considered. They are magically empowered, usually through their association with and proximity to prophecy and divinity, and are thus tasked with ensuring cultural memory is preserved in much the same way the speaker of “The Seeress’s Prophecy” does. The examination follows an analysis of various Giantesses from the second era of the God of War video games series, an adaptation of Angrboda from The Witch’s Heart by Genevieve Gornichec, and Freydís Eiríksdóttir from Vikings: Valhalla. Each of these women prove to be a völva figure in their own unique ways, and thus carry with them the cultural memory as a form of preservation in the face of apocalypses.

The present study examined the relationship between Action Identification and Homosexual Identity Formation. Specifically, it examines how homosexual male individuals view their actions differently when they are “in the closet” (not open about their sexual orientation) compared to being out today (open about their sexual orientation). Homosexual male participants (N=142) took an online survey containing the internalized Homophobia scale, Self-concept clarity scale, and general demographics questions and took the Behavioral Identification Form with an additional 20 items twice (BIF+). The participants were instructed first to answer the BIF+ as if they were in the closet and later took the same form as they are today, being comfortable with their sexual orientation. Using the original 25-item BIF, a paired t-test revealed a significant difference in the out-of-the-closet (M = .65, SD = .19) from the closeted (M = .60, SD =.21), t(141) = 3.3, p < .001. The effect size measured by Cohen’s d was d=.28, indicating a small effect. With the additional 20 items, a paired t-test for the BIF+ revealed a significant difference in the out-of-the-closet (M = .69, SD = .15) condition, compared to being closeted (M = .63, SD = .19), t(141) = 4.4, p<.001. The effect size, measured by Cohen’s d, was d=.37, indicating a small effect. These findings suggest that when homosexual men are closeted, they tend to view their actions at a lower level compared to when they are open about their sexual orientation.

Online shopping is a common feature of modern adult life and is made easy with targeted advertisements, a large buy now button, and pre-entered credit card information. However, these features do not support making purchasing decisions based on what is best for the individual. Decision making about buying items requires an understanding of basic mathematics, one’s current finances and circumstances, and information about the product, then choosing whether to purchase the item. Adults with intellectual and developmental disabilities (IDD) need explicit instruction on how to make informed decisions regarding online purchases.
The current study sought to evaluate the effectiveness of an intervention package consisting of a mnemonic and behavior skills training (BST) delivered remotely to improve the decision making of three adults with IDD when shopping online through a multiple probe across participants design. Inter-observer agreement and procedural fidelity was assessed throughout each phase of the study and social validity interviews were conducted to measure perceptions of participants, parents, and professionals on the importance of the goals, procedures, and outcomes of the study.

The atmospheric concentration of CO2 increased from 320 to 425 parts per million by volume (ppmv; 0.0425 vol.%) between 1960 and 2024. Sample CO2 reduction strategies include shifting to renewable energy sources and employing CO2 capture. CO2 capture from the air (also known as direct air capture; DAC) has recently received increased attention. CO2 has the potential to act as an asphyxiant at high concentrations, particularly in enclosed environments (e.g., spacecraft, submarines), requiring air revitalization to remove CO2. Hence, the U.S. Occupational Safety and Health Administration determined a permissible exposure limit of 5,000 ppmv CO2 (0.5 vol.%) throughout an 8-hour work shift. Considering the trace levels of CO2 and the presence of humidity in DAC and air revitalization applications, similar materials can be developed for implementation in both cases. CO2 capture involving amine-functionalized silica materials (“aminosilicas”) can achieve high CO2 uptakes at low concentrations due to high selectivity. Additionally, moisture in CO2-laden gases enhances the CO2 uptake and stability of aminosilicas. Therefore, this research investigated the potential of aminosilicas for removing CO2 from dilute streams, including DAC and air revitalization applications. Aminosilicas were produced using mesoporous silica supports with different particle sizes that were modified with tetraethylenepentamine (TEPA) or branched polyethylenimine (PEI) with different molecular weights (600, 1200, and 1800), or grafted with 3-aminopropyltrimethoxysilane (APTMS). The performance of aminosilicas was assessed to determine equilibrium CO2 adsorption capacity, adsorption kinetics, and cyclic stability.

Mindfulness is known to positively impact behavioral and electrophysiological outcomes of inhibitory executive control following long-term practice. For example, increased accuracy and decreased reaction time, as well as neural markers of increased inhibitory processing. More evidence is emerging demonstrating increased inhibitory control following shorter-term interventions ranging from 3 days to less than 8 weeks. However, findings following single, brief (>1 hour) remain mixed. The current study measured behavioral and EEG changes on a Stroop task in 40 college students following either a 30-minute guided mindfulness meditation or audiobook listening. A breath-counting task (objective measure of mindfulness) was administered to capture the effectiveness of the intervention. Results showed the mindfulness group had trending increased accuracy on the breath-counting task post-intervention compared to controls. Equivalent performance was seen across all Stroop trial conditions regardless of group. Regarding the EEG findings, a between-group effect emerged for congruent N2 voltage at P4 and incongruent N2 voltages at FC1 indicating the mindfulness group had reduced negative voltages across both time points. There was a within-subjects x group interaction for incongruent P3b voltage at Pz; MG increased while controls decreased (opposite of what was expected). This study provides partial evidence for a single, 30-min mindfulness induction in producing a more mindful awareness compared to an audiobook control group. Findings regarding enhanced inhibitory processing following the mindfulness intervention are mixed. Contrary to expectations, our findings implicate the effectiveness of a 30-min mindfulness induction in increased resource recruitment for evaluating incongruent words in absence of behavioral effects.