Digital Commons Network^™

Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros

USF Tampa Graduate Theses and Dissertations

The human brain still has many mysteries and one of them is how it encodes information. The following study intends to unravel at least one such mechanism. For this it will be demonstrated how a set of specialized neurons may use spatial and temporal information to encode information. These neurons, called Place Cells, become active when the animal enters a place in the environment, allowing it to build a cognitive map of the environment. In a recent paper by Scleidorovich et al. in 2022, it was demonstrated that it was possible to differentiate between two sequences of activations of a …

Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros

USF Tampa Graduate Theses and Dissertations

The human brain still has many mysteries and one of them is how it encodes information. The following study intends to unravel at least one such mechanism. For this it will be demonstrated how a set of specialized neurons may use spatial and temporal information to encode information. These neurons, called Place Cells, become active when the animal enters a place in the environment, allowing it to build a cognitive map of the environment. In a recent paper by Scleidorovich et al. in 2022, it was demonstrated that it was possible to differentiate between two sequences of activations of a …

Determining The P-Wave Velocity Structure In The Near-Surface Of Nw Miami, Florida, Using Quarry Blasts, Elham Moslemi

USF Tampa Graduate Theses and Dissertations

The fact that Florida is an earthquake-free region has caused seismologists to pay less attention to it. Few earthquakes in this state mean it is not a usual practice to study the propagation of seismic waves. However, utilizing data from quarry blasts, we studied wave propagation in this region. The primary objective of the project is to investigate the near-surface P-wave velocity structure and factors that may affect it. We also analyzed the amplitude of signals versus distance and blast size. A network of up to 10 Raspberry Shake instruments around the NW Miami-Lakes mining area was deployed where four …

Determining The P-Wave Velocity Structure In The Near-Surface Of Nw Miami, Florida, Using Quarry Blasts, Elham Moslemi

USF Tampa Graduate Theses and Dissertations

The fact that Florida is an earthquake-free region has caused seismologists to pay less attention to it. Few earthquakes in this state mean it is not a usual practice to study the propagation of seismic waves. However, utilizing data from quarry blasts, we studied wave propagation in this region. The primary objective of the project is to investigate the near-surface P-wave velocity structure and factors that may affect it. We also analyzed the amplitude of signals versus distance and blast size. A network of up to 10 Raspberry Shake instruments around the NW Miami-Lakes mining area was deployed where four …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

All Quiet On The Digital Front: The Unseen Psychological Impacts On Cybersecurity First Responders, Tammie R. Hollis

USF Tampa Graduate Theses and Dissertations

Driven by the increasing frequency of cyberattacks and the existing talent gap between industry needs and skilled professionals, this research study focused on the crucial human element in the domain of cybersecurity incident response. The objective of this dissertation was to offer a meaningful exploration of the lived experiences encountered by cybersecurity incident responders and an assessment of the subsequent impacts on their well-being. Additionally, this study sought to draw comparisons between the experiences of cybersecurity incident responders and their counterparts in traditional emergency response roles. Semi-structured interviews were conducted with a cohort of 22 individuals with first-hand experience working …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Synthetic Studies Of Potential New Ketogenic Molecules, Mohammad Nazmus Sakib

USF Tampa Graduate Theses and Dissertations

The ketogenic diet has gained popularity in the past few decades among people and physicians due to its various health benefits. A significant amount of research has been done for the modification of the original ketogenic diet and investigation of its potential health benefits. However, synthesis of novel ketogenic compounds as a dietary supplement has not received the same level of attention. That is the primary objective of this research project. The first chapter of this manuscript describes the synthesis of various short and medium chain esters of different polyols that have been done so far, and areas of their …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Synthetic Studies Of Potential New Ketogenic Molecules, Mohammad Nazmus Sakib

USF Tampa Graduate Theses and Dissertations

The ketogenic diet has gained popularity in the past few decades among people and physicians due to its various health benefits. A significant amount of research has been done for the modification of the original ketogenic diet and investigation of its potential health benefits. However, synthesis of novel ketogenic compounds as a dietary supplement has not received the same level of attention. That is the primary objective of this research project.

The first chapter of this manuscript describes the synthesis of various short and medium chain esters of different polyols that have been done so far, and areas of their …

All Quiet On The Digital Front: The Unseen Psychological Impacts On Cybersecurity First Responders, Tammie R. Hollis

USF Tampa Graduate Theses and Dissertations

Driven by the increasing frequency of cyberattacks and the existing talent gap between industry needs and skilled professionals, this research study focused on the crucial human element in the domain of cybersecurity incident response. The objective of this dissertation was to offer a meaningful exploration of the lived experiences encountered by cybersecurity incident responders and an assessment of the subsequent impacts on their well-being. Additionally, this study sought to draw comparisons between the experiences of cybersecurity incident responders and their counterparts in traditional emergency response roles. Semi-structured interviews were conducted with a cohort of 22 individuals with first-hand experience working …

Influence Of Thickness And Capping Materials On The Static And Dynamic Properties Of Ferrimagnetic Thin Films, Noha Alzahrani

USF Tampa Graduate Theses and Dissertations

Spintronics traditionally relied on ferromagnetic materials for their strong spin properties but facedissues like large stray magnetic fields. To address these challenges, researchers turned to antiferromagnetic materials with fast spin dynamics, due to their zero net magnetic moment but the lack of a net spin moment complicated operation. In this context, ferrimagnetic materials have emerged as promising alternatives. They combine ferromagnetic and antiferromagnetic traits and feature different magnetic ions in their sublattices. This dissertation explores how film thickness and capping materials affect the properties of ferrimagnetic thin films. Rare-earth transition metal ferrimagnetic amorphous alloys have garnered attention in the realm …

Influence Of Thickness And Capping Materials On The Static And Dynamic Properties Of Ferrimagnetic Thin Films, Noha Alzahrani

USF Tampa Graduate Theses and Dissertations

Spintronics traditionally relied on ferromagnetic materials for their strong spin properties but facedissues like large stray magnetic fields. To address these challenges, researchers turned to antiferromagnetic materials with fast spin dynamics, due to their zero net magnetic moment but the lack of a net spin moment complicated operation. In this context, ferrimagnetic materials have emerged as promising alternatives. They combine ferromagnetic and antiferromagnetic traits and feature different magnetic ions in their sublattices. This dissertation explores how film thickness and capping materials affect the properties of ferrimagnetic thin films.

Rare-earth transition metal ferrimagnetic amorphous alloys have garnered attention in the realm …

Refining The Machine Learning Pipeline For Us-Based Public Transit Systems, Jennifer Adorno

USF Tampa Graduate Theses and Dissertations

According to the Population Division of the United Nations, in the United States, almost 90% of the population will live in urban areas by the year 2050. As the population in a given area increases, higher traffic congestion follows due to an increase of vehicles in the road. A possible way to alleviate congestion could be with widespread use of public transit. However, according to the US Census Bureau, the percentage of individuals commuting through public transportation has been decreasing steadily over time, and the American Community Survey reports that during 2019, only around five percent of the US population …

Refining The Machine Learning Pipeline For Us-Based Public Transit Systems, Jennifer Adorno

USF Tampa Graduate Theses and Dissertations

According to the Population Division of the United Nations, in the United States, almost 90% of the population will live in urban areas by the year 2050. As the population in a given area increases, higher traffic congestion follows due to an increase of vehicles in the road. A possible way to alleviate congestion could be with widespread use of public transit. However, according to the US Census Bureau, the percentage of individuals commuting through public transportation has been decreasing steadily over time, and the American Community Survey reports that during 2019, only around five percent of the US population …

Human Vs Machine: Hyper-Realistic Avatars And Their Efficacy As A Communication Channel, Jill S. Schiefelbein

USF Tampa Graduate Theses and Dissertations

Hyper-realistic avatars (HRAs), a form of synthetic media, are custom-created digital embodiments of a human, created by capturing and combining that person’s video and vocal likeness. This is the first known study of the efficacy of videos delivered by hyper-realistic avatars as a communication channel in comparison to videos delivered by their human counterparts. An experiment testing how information retention, engagement, and trust vary between viewers of videos delivered by a real human, videos delivered by the HRA representing that same human, and videos delivered by the HRA that discloses to viewers that it is a hyper-realistic avatar is presented. …

Human Vs Machine: Hyper-Realistic Avatars And Their Efficacy As A Communication Channel, Jill S. Schiefelbein

USF Tampa Graduate Theses and Dissertations

Hyper-realistic avatars (HRAs), a form of synthetic media, are custom-created digital embodiments of a human, created by capturing and combining that person’s video and vocal likeness. This is the first known study of the efficacy of videos delivered by hyper-realistic avatars as a communication channel in comparison to videos delivered by their human counterparts. An experiment testing how information retention, engagement, and trust vary between viewers of videos delivered by a real human, videos delivered by the HRA representing that same human, and videos delivered by the HRA that discloses to viewers that it is a hyper-realistic avatar is presented. …

Using Social Network Analysis To Measure And Visualize Student Clustering Within Middle And High Schools, Geoffrey David West

USF Tampa Graduate Theses and Dissertations

The dominant philosophy of American public schools has been to group students together based on similar characteristics. Known as tracking, high achieving students would take courses on the “college track” while others would take “career track” courses. It was not long until advocates noticed that this process unfairly advantaged affluent and White student over poor and minoritized groups. A new process called “ability grouping” took over where tracking left off, but to the same effect. It is difficult to measure the degree students are grouped together by a certain characteristic, and while a few research papers aim to do so, …

Using Social Network Analysis To Measure And Visualize Student Clustering Within Middle And High Schools, Geoffrey David West

USF Tampa Graduate Theses and Dissertations

The dominant philosophy of American public schools has been to group students together based on similar characteristics. Known as tracking, high achieving students would take courses on the “college track” while others would take “career track” courses. It was not long until advocates noticed that this process unfairly advantaged affluent and White student over poor and minoritized groups. A new process called “ability grouping” took over where tracking left off, but to the same effect. It is difficult to measure the degree students are grouped together by a certain characteristic, and while a few research papers aim to do so, …

Deciphering Trends And Tactics: Data-Driven Techniques For Forecasting Information Spread And Detecting Coordinated Campaigns In Social Media, Kin Wai Ng Lugo

USF Tampa Graduate Theses and Dissertations

The main objective of this dissertation is to develop models that predict and investigate the spread of information in social media over time. In this context, we consider topics of discussions as the information that spreads. Thus, we are interested in forecasting the number of messages per day in a future interval of time. We take a data-driven approach, in which we compare our results with real datasets from a multitude of socio-political contexts and from multiple social media platforms, specifically, Twitter and YouTube.

We identified a number of challenges related to forecasting social media time series per topic. First, …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Deciphering Trends And Tactics: Data-Driven Techniques For Forecasting Information Spread And Detecting Coordinated Campaigns In Social Media, Kin Wai Ng Lugo

USF Tampa Graduate Theses and Dissertations

The main objective of this dissertation is to develop models that predict and investigate the spread of information in social media over time. In this context, we consider topics of discussions as the information that spreads. Thus, we are interested in forecasting the number of messages per day in a future interval of time. We take a data-driven approach, in which we compare our results with real datasets from a multitude of socio-political contexts and from multiple social media platforms, specifically, Twitter and YouTube.

We identified a number of challenges related to forecasting social media time series per topic. First, …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands. In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (~1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands.

In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (∼1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …