Physical Sciences and Mathematics Commons^™

The Effects Of Surface-Water Flow On The Quality Of Groundwater And Surface-Water Systems, Quanghee Yi

USF Tampa Graduate Theses and Dissertations

My research has focused on the effects of surface-water flow on the quality of groundwater and surfacewater systems. For the first part of my research (Chapter 2 ), I s tudied the effects of s urface flow system changes in the water-conservation areas and canals in southeast Florida on the quality of groundwater in the surficial aquifer system.

For the second part of my research, by developing analytical models using the superposition method, I investigated the effects of bidirectional surface-water flow on the conservative contaminant concentrations (Chapter 4) and mean residence time (Chapter 5) in streams and rivers as well …

Structural And Agricultural Value At Risk In Florida From Flooding During Hurricane Irma, Alexander J. Miller

USF Tampa Graduate Theses and Dissertations

Flooding is the most costly type of natural disaster, as well as the most frequent. To provide risk-based flood insurance, providers such as FEMA must be able to accurately determine an asset’s risk of flooding. Additionally, after a flooding event, providers need to quickly determine the direct damages that occurred to verify insurance claims and provide assistance to the affected communities. Many current approaches to flood risk and flood damage estimation involve the use of data or statistical extrapolation that can add various sources of uncertainty into the final damage estimate. In order to reduce uncertainties in flood risk analyses, …

Van Der Waals Epitaxy Of Ultrathin Early Transition Metal (Ti & V) (Di)Selenides: Charge And Magnetic Order In The Ultrathin Limit, Manuel Bonilla Lopez

USF Tampa Graduate Theses and Dissertations

Since the isolation of graphene in 2004, two-dimensional (2D) layered materials, specially the transition metal dichalcogenides (TMDs), have attracted immense interest from theoreticians and experimentalist due to the diversity of properties presented in this family of materials. The main reason for the interest in such materials has been the observation of emergent properties as a consequence of the reduced dimensions, i.e. the monolayer regime. Initially the monolayer regime was obtained via the scotch-tape method. The implementation of exfoliation techniques was successful since layered 2D materials are composed of stacked layers held together by weak van der Walls forces that permits …

Biogeochemical Cycling Of Nutrients And Carbon In Subtropical Wetlands, Lauren N. Griffiths

USF Tampa Graduate Theses and Dissertations

As human development intensifies, ecosystems around the word are being exponentially destroyed and degraded. Wetlands have the capacity to mitigate some of the possible problems by retaining nutrients and carbon, keeping them from harming downstream ecosystems or being released into the atmosphere. This project focuses on the processes that make wetlands successful by studying two unique ecosystems: 1) a created urban stormwater treatment wetland and 2) mangrove wetlands in Florida and Puerto Rico that were affected by hurricanes in 2017.

The first phase of this study investigates the role of sedimentation and vegetative and algal uptake of nutrients to retain …

Using Geophysical And Geodetic Data To Improve Natural And Human-Induced Hazard Assessments, Fanghui Deng

USF Tampa Graduate Theses and Dissertations

I use geophysical and geodetic data to study dynamics of the Earth System, including volcanoes and induced seismicity, aiming to improve related hazard assessment at different time and space scales. My dissertation consists of the following three projects: 1) Geophysical model for the origin of volcano vent clusters (Deng et al., 2017). We developed a conceptual model to simulate long-term magma transport to explain the origin of volcanic vent clusters in Quaternary Colorado Plateau volcanic fields. We used density contrast inverted from gravity data to constrain the magma transport model. The development of vent clusters appears to be influenced by …

Development Of A Benthic Foraminifera Based Marine Biotic Index (Foram-Ambi) For The Gulf Of Mexico: A Decision Support Tool, Bryan O'Malley

USF Tampa Graduate Theses and Dissertations

The Gulf of Mexico (GoM) is an economically important region (e.g. oil and gas, fisheries) and with the expansion of oil drilling, harmful algal bloom events, oil blowouts, dead zones, anthropogenic eutrophication and contaminant loading, it is important that the ecological quality statuses (EcoQS) of different localities in the Gulf are closely monitored. The EcoQS, as implemented by the European Water Framework Directive, is an effective tool for monitoring ecological health and developing reference conditions. One such index used to define EcoQS is the AZTI Marine Biotic Index (AMBI), which pairs species abundance with environmental stressors. Benthic foraminifera are ideal …

Bayesian Reliability Analysis For Optical Media Using Accelerated Degradation Test Data, Kun Bu

USF Tampa Graduate Theses and Dissertations

ISO (the International Organization for Standardization) 10995:2011 is the inter-national standard providing guidelines for assessing the reliability and service life of optical media, which is designed to be highly reliable and possesses a long lifetime. A well-known challenge of reliability analysis for highly reliable devices is that it is hard to obtain sufficient failure data under their normal use conditions. Accelerated degradation tests (ADTs) are commonly used to quickly obtain physical degradation data under elevated stress conditions, which are then extrapolated to predict reliability under the normal use condition. This standard achieves the estimation of the lifetime of recordable media, …

Investigating The Isotope Signatures Of Dissolved Iron In The Southern Atlantic Ocean, Brent A. Summers

USF Tampa Graduate Theses and Dissertations

Iron (Fe), used as a cofactor in nitrogen fixation and photosynthesis by oceanic microorganisms, has extremely low dissolved concentrations in the surface ocean, leading to widespread limitation of phytoplankton growth. Dissolved Fe isotope ratios (δ56Fe) have been shown to be useful in helping to quantify the sources and cycling of Fe in the oceans if Fe source signatures and fractionation processes are well understood. Here, this thesis presents data from GEOTRACES section GA10W, and investigate the isotopic signature of sediment-derived dissolved Fe from the South Atlantic margins. My results show that there are both shallow (δ56Fe of -0.2‰) and deep …

Action Recognition Using The Motion Taxonomy, Maxat Alibayev

USF Tampa Graduate Theses and Dissertations

In the last years, modern action recognition frameworks with deep architectures have achieved impressive results on the large-scale activity datasets. All state-of-the-art models share one common attribute: two-stream architectures. One deep model takes RGB frames, while the other model is fed with pre-computed optical flow vectors. The outputs of both models are combined to be used as a final probability distribution for the action classes. When comparing the results of individual models with the fused model, it is common to see that that latter method is more superior. Researchers explain that phenomena with the fact that optical flow vectors serve …

Sentiment Analysis In Peer Review, Zachariah J. Beasley

USF Tampa Graduate Theses and Dissertations

Sentiment analysis, a widely popular subfield of natural language processing, has recently been used in the classroom to predict student attrition or to determine the mood of students, teacher strengths and weaknesses, or student perception of internship experience. These are all helpful indicators for the enhancement of students' academic experience but none improve the information gathered from or the reliability of peer review. This is particularly important in large courses with complex assignments (e.g., essays, software projects, and presentations) where scalable grading is requisite. In this dissertation, we apply sentiment analysis not on an assignment itself, but on the meaningful …

Automating The Classification Of Mosquito Specimens Using Image Processing Techniques, Mona Minakshi

USF Tampa Graduate Theses and Dissertations

According to WHO (World Health Organization) reports, among all animals, mosquitoes are responsible for the most deaths worldwide. Mosquito borne diseases continue to pose grave dangers to global health. In 2015 alone, 214 million cases of malaria were registered worldwide. According to Centers for Disease Control and Prevention (CDC) report published in 2016, 62,500 suspected case of Zika were reported to the Puerto Rico Department of Health (PRDH) out of which 29,345 cases were found positive. The year 2019 was recorded as the worst for dengue in South East Asia. There are close to 4,500 species of mosquitoes (spread across …

Investigation Into Reduced Thermal Conductivity For Half-Heusler Alloys And Identification Of Novel Multinary Chalcogenides Possessing Intrinsically Low Thermal Conductivity, Dean Hobbis

USF Tampa Graduate Theses and Dissertations

The current climate makes the need for sustainable energy production a priority, leading to keen interest towards the advancement of “green” energy sources and technology. This necessity has led to a multidisciplinary scientific approach with collaborations across various fields that are looking to solve this extremely important problem. One such technology is thermoelectric devices, which are attractive due to the fact that they provide direct solid-state conversion of heat to electrical power, and vice versa. This in turn allows for both waste heat recovery and sustainable refrigeration. One key aspect that is preventing the wide scale commercial use of thermoelectric …

Exploring The Potential Of Nutrient Retention And Recycling With Wetlaculture Systems In Ohio With Physical And Landscape Models, Bingbing Jiang

USF Tampa Graduate Theses and Dissertations

Significant expansion of agricultural land use has been widely recognized for leading to global and regional negative environmental impacts, especially increased eutrophication of surface water systems for the last half-century. The landscape-scale environmental problem of overloading nutrients to lakes and streams by excessive fertilizer use and increased human-caused N-fixation is in urgent need of a sustainable landscape-scale solution. Wetlands have long been considered as an effective way to remove nutrients from surface water. However, the influence of regional seasonality and hydrologic conditions on agricultural runoff treatment wetlands still needs more investigation. A new approach, “wetlaculture,” has recently described as a …

Privacy-Preserving And Functional Information Systems, Thang Hoang

USF Tampa Graduate Theses and Dissertations

Information systems generally involve storage and analytics of large-scale data, many of which may be highly sensitive (e.g., personal information, medical records). It is vital to ensure that these systems not only provide essential functionalities at large scale efficiently but also achieve a high level of security against cyber threats. However, there are significant research challenges in offering security and privacy for such information systems while preserving their original functionalities (e.g., search, analytics) effectively. Hence, there is a critical need for efficient cryptographic protocols that can address data privacy vs. utilization dilemma for real-life applications.

In this dissertation, we introduce …

Do Similar Exposure Groups (Seg) Differ From Air Force Base To Air Force Base? A Combat Arms Training And Maintenance (Catm) Noise Exposure Comparison Of Moody Afb And Macdill Afb., Miriam F. Escobar

USF Tampa Graduate Theses and Dissertations

Noise is a common hazard for the military. The Department of Defense has set an Occupational Exposure Limit for noise at 85 dBA. The Air Force manages exposures using similar exposure groups (SEGs) which are formed at each Air Force Base. The purpose of this study was to compare the noise levels in SEGs in two Air Force bases across distance and time, and to review the effectiveness of the Air Force Hearing Conservation Program over distance and time. The SEGs chosen were Combat Arms Training and Maintenance (CATM) at Moody Air Force Base and MacDill Air Force Base because …

Reimagining Bottom-Up Participatory Climate Change Adaptation In The Philippines, Emily Clark Nabong

USF Tampa Graduate Theses and Dissertations

While climate change trends indicate the progression towards more widespread and severe impacts across the world, current consequences of society’s climate inaction are already being felt by many vulnerable populations. Low-lying and coastal areas are particularly at risk from climate-related hazards such as sea level rise and increased intensity storms. In order to protect residents, countries and regional governments have begun to plan and implement adaptation strategies to minimize the impact of future climate change related disasters.

This thesis explores the current status of bottom-up participatory climate change adaptation planning in the Philippines and offers new insights into making this …

Identification Of Patterns And Disruptions In Ambient Sensor Data From Private Homes, Yan Wang

USF Tampa Graduate Theses and Dissertations

The world’s population is rapidly aging and the increasing demand for home and health care services from this aging population brings unprecedented challenges to the economy and society. Ambient-assisted smart homes, residences equipped with ambient sensors to monitor the resident’s daily activities in a continuous and unobtrusive way, present great potential to manage the growing care service needs of this older population segment, and enable them to age-in-place.

Despite growing research, using ambient sensor data from private homes to monitor daily activities, health and wellness still faces significant challenges. To study ambient sensor data from private homes where annotated data …

Design Of Support Measures For Counting Frequent Patterns In Graphs, Jinghan Meng

USF Tampa Graduate Theses and Dissertations

In recent years, the popularity of graph datasets has grown rapidly. Frequent subgraph mining (FSM) from graphs becomes an important subject in computer science research. In this dissertation, we study single-graph as an effective model to represent information and its related graph mining techniques. In frequent pattern mining in a single-graph setting, there are two main problems: support measure and search scheme. We study the development of support measures, which are basically functions that map a pattern to its frequency count in a database. Our work is based on the hypergraph framework using the concept of occurrence/instance hypergraphs. We present …

Breakthroughs In Obtaining Qm/Mm Free Energies, Phillip S. Hudson

USF Tampa Graduate Theses and Dissertations

The computation of free energy is pivotal to understanding the fundamental nature of chemical phenomena. That is, whether a specific molecular outcome occurs spontaneously or is inherently unfavorable. The need to do this with consistent accuracy begs for the use of quantum mechanical (QM) methods. However, techniques for directly computing free energy differences with QM or mixed QM/MM methods are untenable, as the computational expense is quite exorbitant. At present, the most feasible approach for obtaining QM/MM free energies is employing the so-called indirect cycle, which relies on accurately computing free energy differences between low (e.g., molecular mechanical, MM) and …

Service Provisioning And Security Design In Software Defined Networks, Mohamed Rahouti

USF Tampa Graduate Theses and Dissertations

Information and Communications Technology (ICT) infrastructures and systems are being widely deployed to support a broad range of users and application scenarios. A key trend here is the emergence of many different "smart" technology paradigms along with an increasingly diverse array of networked sensors, e.g., for smart homes and buildings, intelligent transportation and autonomous systems, emergency response, remote health monitoring and telehealth, etc. As billions of these devices come online, ICT networks are being tasked with transferring increasing volumes of data to support intelligent real-time decision making and management. Indeed, many applications and services will have very stringent Quality of …

Climate Change And Liberation In Latin America, Ernesto O. Hernández

USF Tampa Graduate Theses and Dissertations

The purpose of this dissertation is to propose the liberation movements in Latin America as alternative philosophical frameworks to the crisis of climate change. These movements have provided the grounds to identify inequities and injustices and have practiced ethical methodologies to overcome them. Additionally, the movements seek to represent and reflect the value of non-traditional philosophical agents in Latin America. The work focuses on four major Latin American ecological liberation movements; theology, philosophy, pedagogy, and feminism. Eco-Theology advances the role of Religion as the practice of Religação, reexamination, and resetting our relationship with nature by reconnecting with it. Eco-Philosophy of …

Growth And Characterization Of 2d Layered Materials, Algene Fryer Ii

USF Tampa Graduate Theses and Dissertations

2D layered materials are becoming an important area of research due to their exceptional electrical and optical properties. Specifically, 2D layered monochalcogenides are known for their high carrier motilities, whereas layered metal halides have been shown to have noteworthy photoresponsivity. Despite the assortment of 2D layered materials, the search for reliable and scalable synthesis methods is still a challenge in this family of materials. Often a certain growth technique will compromise a desirable trait needed for further fabrication, such as the quality of the crystal or its coverage on a substrate. In this study, two growth techniques that incorporate changeable …

New Synthetic Methodology Using Base-Assisted Diazonium Salts Activation And Gold Redox Catalysis, Abiola Azeez Jimoh

USF Tampa Graduate Theses and Dissertations

Over the past two decades, homogeneous Au(I) catalysis has been a valuable synthetic tool for activating a series of unsaturated carbon-carbon bonds towards nucleophilic attack. Despite this progress, Au(I/III) redox chemistry has not been well explored. This is largely due to the challenges associated with the high oxidation potential of gold. Hence, the need for an efficient and safe method for Au oxidation.

Herein, a base-assisted diazonium salt activation has been used to facilitate Au redox reactions under mild reaction conditions. This oxidative coupling method afforded functional isoxazolines with good to excellent yields, while the alternative photoactivation method provided trace …

Artificial Intelligence Towards The Wireless Channel Modeling Communications In 5g, Saud Mobark Aldossari

USF Tampa Graduate Theses and Dissertations

Channel prediction is a mathematical predicting of the natural propagation of the signal that helps the receiver to approximate the affected signal, which plays an important role in highly mobile or dynamic channels. The standard wireless communication channel modeling can be facilitated by either deterministic or stochastic channel methodologies. The deterministic approach is based on the electromagnetic theories and every single object in that environment has to be known in that propagation space and an example of this method is ray tracing. While the stochastic modeling method is based on measurements that involve statistical distributions of the channel parameters and …

Post-Overlay Flexible Pavement Performance Modeling And Its Application In Sustainable Asphalt Overlay Policy Making, Chunfu Xin

USF Tampa Graduate Theses and Dissertations

Highway pavement is a critical component of the highway transportation infrastructure. After the construction of a pavement system, pavement condition will deteriorate over time due to a combination effect of material aging, traffic loading, and environmental impact. To restore the pavement performance and to reduce its adverse effects on public users and environment, asphalt overlay activities are conducted frequently during the service life of a pavement. As a key component that bridges the overlay policies with future pavement performance, economic cost and environmental impact, the forecast accuracy of post-overlay pavement performance model is extremely important. However, most of previous studies …

Keyless Anti-Jamming Communication Via Randomized Dsss, Ahmad Alagil

USF Tampa Graduate Theses and Dissertations

Nowadays, wireless networking is ubiquitous. In wireless communication systems, multiple nodes exchange data during the transmission time. Due to the natural use of the communication channel, it is crucial to protect the physical layer to make wireless channels between nodes more reliable. Jamming attacks consider one of the most significant threats on wireless communication. Spread spectrum techniques have been widely used to mitigate the effects of the jammer. Traditional anti-jamming approaches like Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS) require a sender and a receiver to share a secret key prior to their communication. If this …

Complexities Of Data, Tasks And Workflows In Health It Management, Gaurav Jetley

USF Tampa Graduate Theses and Dissertations

This dissertation focuses on three key aspects in health IT management: (1) Complexities in the collection of health data in electronic health record (EHR) systems and the use of EHR data in research, (2) Complexities of collaboration between physicians and AI for improving healthcare delivery, and (3) Complexities of workflows and collaborations between healthcare organization (HCO) staff during the delivery of care. The first dissertation essay (Chapter 1) examines the key data quality issues that arise in recorded health information in EHR systems, provides quality thresholds that the data needs to meet for mitigating errors and increasing reproducibility of downstream …

Models Of Secure Software Enforcement And Development, Hernan M. Palombo

USF Tampa Graduate Theses and Dissertations

Computer Security has been a pressing issue that affects our society in multiple ways. Although a plethora of security solutions have been proposed and implemented throughout the years, security continues to be a problem for at least two important reasons, (1) implementations of runtime enforcement mechanisms have not been modeled rigorously and thus may not be enforcing the policies that are expected to enforce, and (2) there are conflicting tensions in the software development process that hinder the implementation and maintenance of secure software. To investigate these issues, this dissertation is divided into two parts.

The first part of this …

Composition Of Atomic-Obligation Security Policies, Danielle Ferguson

USF Tampa Graduate Theses and Dissertations

There has been significant work to date on policy-specification languages that allow specification of arbitrary obligations, but there continues to exist open challenges in the composition of these arbitrary obligations, especially when obligations can be complex (i.e. consist more than one action). There are currently no solutions that allow complete and automatic resolution of conflicts between policies and other policies' obligations or that allow policies to react to the complex obligations of other policies. In particular, there is minimal work that considers the benefits and challenges of allowing complex obligations that operate in an atomic fashion, that is that execute …

Developing Agent-Based Models To Study Financial Markets, Saurav Chakraborty

USF Tampa Graduate Theses and Dissertations

This dissertation presents research that employs agent-based modelling to provide a framework to support simulation as a complement to traditional economic models for policy evaluation. It consists of three studies. The first study employs cluster analysis to capture the different types of banks and the associated business models that define their decision-making. The results from study one will help us get an understanding of how different banks behave and provide an insight into their lending practices. Hence, it would be very helpful in evaluating and analyzing the impact of future policies. Study two develops a fine-grained interbank lending model based …