Physical Sciences and Mathematics Commons^™

Sequential Recommendation: From Representation Learning To Reasoning, Lei Wang

Dissertations and Theses Collection (Open Access)

The recommender system is a crucial component of today's online services. It helps users navigate through an overwhelmingly large number of items and discovering those that interest them. Unlike general recommender systems, which recommend items based on the user's overall preferences, sequential recommender systems consider the order of user-item interactions. Sequential recommendations aim to predict the next item a user will interact with, given a sequence of previously interacted items, while considering the short-term and long-term dependencies among items.

In this thesis, we focus on sequential recommendation methods: from representation learning to large language model (LLM)-based reasoning. On the one …

Combine Shapelets, Zeng Qingwen

LMU/LLS Theses and Dissertations

Sensor-based human activity recognition has become an important research field within pervasive and ubiquitous computing. Techniques for recognizing atomic activities such as gestures or actions are mature for now, but complex activity recognition still remains a challenging issue. I was a candidate in an activity classification thesis. It collected 4 activities, which included walking on the sidewalk for a set distance, walking up and down a set of stairs, walking on the treadmill at 2.5 mph for 2 minutes, and jogging on the treadmill at 5.5 mph for 1 minute. It took 30 minutes to collect one candidate data. If …

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh

LSU Master's Theses

The marine cyanobacterium Synechococcus sp. CCMP 1334 was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nitrate availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21°C, 24°C, 28°C, 32°C, and 35°C. The maximum median nutrient-replete growth rate was ~1.15 d−1 at 32 –35°C. Median growth rates at 1000 ppmv pCO2 were higher than those at 400 ppmv at all temperatures, but most of the differences were statistically insignificant. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate but decreased with …

Thermal Ecology And Swimming Performance Of Native Tadpoles Dryophytes Femoralis In Central Florida, Jessalyn Aretz

USF Tampa Graduate Theses and Dissertations

Urbanization and climate warming have contributed to global amphibian declines in recent decades. Amphibians are particularly vulnerable to climate and urban-induced warming because their physiological processes are dependent on temperature across all life stages, but few studies have been done on tadpole responses to warming in comparison to adult responses. The study objective was to determine how the thermal ecology and swimming performance of a native Florida tadpole varied with rearing temperature and urban level, and whether these traits are plastic or adaptive. We collected eggs from wild populations of pine woods treefrog (Dryophytes femoralis) tadpoles at an urban and …

Advancing Depth-Storage-Discharge Modeling In Regional Hydrology, Fahad Alshehri

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of an innovative approach to populating rating characteristics and supporting hydrologic modeling, designed to simplify complex real-world hydrological systems and accurately estimate their responses to rainfall, runoff, baseflow and evaporation stresses. The core of this research addresses the challenges inherent in characterizing hydrography elements in hydrologic modeling, particularly in regions lacking comprehensive stream reach survey data, flow and stage. This issue is pronounced in areas with extensive wetland hydrography, where traditional modeling requires intensive manual calibration, and course rating data that are often unavailable. To overcome these challenges, this study introduces a novel procedure that …

Individual Behavioral Modeling Across Games Of Strategy, Logan Fields

USF Tampa Graduate Theses and Dissertations

An individual’s actions in a particular environment and with specified resources can reveal their decision-making tendencies and patterns, and by analyzing the variations in cognitive traits among individuals, it may be possible to identify trends that can foretell their future behaviors. This can be a powerful tool in various fields including cognitive modeling, player analytics, computer security, and threat detection. Collectible card games are a fruitful test space for studying cognitive differences in decision-making, as they can have clearly defined and replicable environments and large player bases. As such, in this work, I explore the potential of using two virtual …

Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent

LSU Master's Theses

Submarine pipelines and cables are vital for transmitting physical and digital resources across bodies of water, necessitating regular inspection to assess maintenance needs. The safety of subsea pipelines and cables is paramount for sustaining industries such as telecommunications, power transmission, water supply, waste management, and oil and gas. Incidents like those involving the Nord Stream subsea pipeline and the SEA-ME-WE 4 subsea communications cable exemplify the severe economic and environmental consequences of damage to these critical infrastructures. Existing inspection methods often fail to meet accuracy requirements, emphasizing the need for advancements in inspection technologies. This comprehensive survey covers the sensors …

An Analysis And Ontology Of Teaching Methods In Cybersecurity Education, Sarah Buckley

LSU Master's Theses

The growing cybersecurity workforce gap underscores the urgent need to address deficiencies in cybersecurity education: the current education system is not producing competent cybersecurity professionals, and current efforts are not informing the non-technical general public of basic cybersecurity practices. We argue that this gap is compounded by a fundamental disconnect between cybersecurity education literature and established education theory. Our research addresses this issue by examining the alignment of cybersecurity education literature concerning educational methods and tools with education literature.

In our research, we endeavor to bridge this gap by critically analyzing the alignment of cybersecurity education literature with education theory. …

Home Is Where The Work Is: How Biases In Managers’ Resource Allocation Decisions Affect Task Performance In Remote Work Environments, Richard D. Mautz Iii

USF Tampa Graduate Theses and Dissertations

As the use of remote and hybrid work arrangements continues to grow, it is important to understand how these arrangements can yield performance. In this paper, I conduct two studies to examine how the remote work environment affects managers’ task assignment decisions across different task types and how those decisions affect workers’ task performance. First, I survey managers, in both a cross-section of industries and specifically in accounting, to study the effect of remote work on their task assignment decisions. Consistent with prior literature and economic theory, I predict and find that managers are more inclined to assign generative tasks …

Introductory Chemistry Student Success: Evaluating Peer-Led Team Learning And Describing Sense Of Belonging, Jessica D. Young

USF Tampa Graduate Theses and Dissertations

Identifying approaches that make science and engineering education broader and more inclusive is core to discipline based education research. Both fundamental and applied research are important in advancing a STEM education that retains the necessary scientists of the U.S.’s future. Thus, the major goal of this work was to evaluate and describe efforts that promote student success within introductory STEM courses. This began with applied research by utilizing quantitative analyses like case-matching, logistic regression, independent sample t-tests, and repeated measures while evaluating the efficacy of peer-led team learning (PLTL). Later, this work delves into qualitative approaches to answer fundamental research …

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …

Characterizing And Mitigating Transient Noise In Ligo Observatories For Gravitational Wave Detection, Jane Glanzer

LSU Doctoral Dissertations

The existence of gravitational waves is predicted by Albert Einstein's Theory of General Relativity. Commonly referred to as "ripples in spacetime", these waves are generated by some of the most violent and energetic processes in the universe. Despite their theoretical prediction over a century ago, it wasn't until 2015 that the Advanced LIGO (aLIGO) interferometers in Hanford, WA and Livingston, LA directly detected gravitational waves for the first time, confirming Einstein's theory and ushering in a new era of astrophysics.

Detecting gravitational waves requires incredible precision. Because of the extreme sensitivity required, it is possible for the gravitational wave data …

Explorations On Non-Covalent Interactions: From Supramolecules To Drug-Like Molecules, Zhanpeng Zhang

USF Tampa Graduate Theses and Dissertations

Non-covalent interactions are everywhere in our material world. From the microstructures of organisms to the functional materials used in industrial production, whenever matter exists, there are non-covalent interactions between the molecules that build up the matter.The exploration of non-covalent forces helps people understand the intrinsic principles of life processes, it can be applied to create new supramolecular materials as well. Supramolecular chemistry is a research field focusing on the properties and applications of non-covalent interactions. Various non-covalent interactions, such as hydrogen bonds, metal-ligand coordination, π-π interaction, hydrophobic interaction, etc., are objects of research in supramolecular chemistry.

Not only supramolecular chemists, …

On The Subelliptic And Subparabolic Infinity Laplacian In Grushin-Type Spaces, Zachary Forrest

USF Tampa Graduate Theses and Dissertations

This thesis poses the ∞-Laplace equation in Grushin-type spaces. Grushin-type spaces G are defined by the vector fields which serve as a basis for their tangent spaces; by weighting the canonical (Euclidean) directional vectors {∂/∂x_i}ⁿ_i=1 by functions ρ_i that obey certain technical assumptions, we produce a class of metric spaces in which certain directions may not be accessible at all points in the space. We prove the existence and uniqueness of viscosity solutions to both Dirichlet problems and Cauchy-Dirichlet problems involving the∞-Laplacian over bounded Grushin-type domains. The main tool in proving uniqueness of …

Interfacial Magnetism And Anisotropy In Dirac And Weyl Semimetals, Noah Schulz

USF Tampa Graduate Theses and Dissertations

Semimetals have gained intense interest recently due to their exotic magnetic and electronic properties. One of the most widely studied semimetals is graphene, a Dirac semimetal. The utilization of graphene in devices and sensors requires interfacing it with other materials, which may induce potentially strong interfacial effects. Furthermore, graphene alone does not possess magnetic order. Studying the interfacial effects between graphene and magnetic materials is therefore of great importance in the application of graphene to meet modern technological needs. Furthermore, by understanding the fundamental interfacial physics between graphene and magnetic materials, new properties can be unlocked, broadening the possible applications …

Birkhoff Summation Of Irrational Rotations: A Surprising Result For The Golden Mean, Heather Moore

University Honors Theses

This thesis presents a surprising result that the difference in a certain sums of constant rotations by the golden mean approaches exactly 1/5. Specifically, we focus on the Birkhoff sums of these rotations, with the number of terms equal to squared Fibonacci numbers. The proof relies on the properties of continued fraction approximants, Vajda's identity and the explicit formula for the Fibonacci numbers.

Spectroscopic End Point Detection With An Electron Beam Evaporator, Ryan Mcgraw

University Honors Theses

Spectroscopic end point detection is a common tool used for measuring slope changes in wavelength intensity. Using algorithms able to apply this concept, coatings will be able to be dynamically measured in real time and stopped at the appropriate level to ensure process uniformity. It is currently applied to reductive processes such as etching, where the surface will start to be eaten away, creating a plasma. When the entire amount of a material on a substrate has been eaten away, the plasma will change color as it is beginning to etch a different material. Using a spectrometer, this point where …

Unraveling Biases And Customer Heterogeneity In E-Commerce Recommendation Systems, Sachin Sharma

Dissertations

This research explores the biases present in AI algorithms within e-commerce recommendation systems, focusing on how these biases prioritize popular, sponsored, and private-label products over actual customer preferences. We extend the responsible AI discourse by critically examining these biases and their implications for fairness in e-commerce. To strengthen the current understanding of AI fairness in the fields of information systems and computer science, we aim to challenge the assumption that AI fairness is objective and the same for everyone. We examine how individual differences, such as equity sensitivity and exchange ideology, contribute to users' varied perceptions of AI fairness. Through …

N-H Nhc Palladium Catalysts Derived From Unique 2-Phosphinoimidazole Precursors For C-C Cross Coupling Reactions And Application Of Slow Releasing Polymers Impregnated With Gibberellic Acid To Overcome Seed Dormancy For Land Reclamation, Alexandra Jean Setelin Larson

Theses and Dissertations

Organometallic chemistry is highly dependent upon the ligands which are employed on a metal's surface. These ligands control steric bulk and electronics of the metal center which can change the reactivity of the organometallic complex. Ligands that are standard in organometallic chemistry include phosphine ligands. These phosphine ligands have been utilized in the field since the 1960's and have shaped the development of many key organometallic catalysts. Phosphine ligands are easily functionalized and highly reactive. This increased reactivity, however, causes severe limitations as phosphine ligands are often unstable under standard benchtop conditions and must be handled both air and moisture …

Development And Evaluation Of Novel Applications For The Ethos Cbct-Guided Online Adaptive Radiotherapy System, Nour Nasser

USF Tampa Graduate Theses and Dissertations

Radiation therapy (RT) is an important pillar of modern cancer treatment, in neoadjuvant, curative, adjuvant, and palliative settings. The physics underlying RT is ionizing radiation that produces charged particles, which deposit their energy in the tissues they pass through. This energy results in unrepairable DNA damage resulting in the death of cancer tissue. The aim of RT is to deliver the desired radiation dose to the tumor while maximizing normal tissue sparing. Over the past decades, physics, engineering, and computational improvements has allowed advancement of external beam RT techniques, for example from 2D RT to 3D RT to now intensity …

Dissolved Nitrogen Removal In Biochar Amended, High Permeability Media For Urban Stormwater Treatment, Mark Vicciardo

USF Tampa Graduate Theses and Dissertations

Nutrient pollution in stormwater drives the eutrophication of inland and costal waterbodies which leads to sea grass retreat and the proliferation of harmful algal blooms (HAB). These anthropogenic effects destabilize ecosystems, and some HABs can pose direct human health risk. Bioretention, or the storage and controlled discharge of stormwater run-off in an ecologically engineered setting, is a potential solution to this problem. However, it relies heavily on the settling of particles as a nutrient removal mechanism, and thus struggles with pollutants, such as dissolved nitrogen, which is a particular problem in Florida where the geological prominence of phosphorus leaves nitrogen …

Understanding Waveguides In Resonance, Pieter Johannes Daniel Vandenberge

Dissertations and Theses

Several important classes of modern optical waveguides, including anti-resonant reflecting and photonic bandgap fibers, make use of geometries that guide energy in low refractive index material, a property that makes them of significant interest in numerous applications, notably including high-power delivery and guidance. These waveguides frequently exhibit resonance phenomena, in which their ability to propagate an input signal is sharply curtailed at particular operating frequencies. In this work we detail new advances in understanding these resonance effects and their implications for numerical modeling of these structures.

Part 1 focuses on the fields of slab waveguides, relatively simple structures for which …

Automatic Image-Based Nutritional Calculator App, Kejvi Cupa

USF Tampa Graduate Theses and Dissertations

Nutrition plays a pivotal role in shaping an individuals’ health and quality of life, making the evaluation of dietary intake crucial for promoting healthier lifestyle choices. Various solutions, particularly mobile apps, have been developed to facilitate the process of dietary estimation. Accurate nutritional intake assessment relies on two key components: ingredient recognition and food portion estimation. For a mobile app to offer a comprehensive solution for automatic nutritional assessment, it must address both components.

In this work, we focus on a mobile app pipeline: the semi-automatic pipeline which focuses on automatic food ingredient recognition. This pipeline integrates state-of-the-art models for …

Semi-Automated Cell Annotation Framework Using Deep Learning, Abhiram Kandiyana

USF Tampa Graduate Theses and Dissertations

Unbiased stereology refers to a field of applied mathematics \cite{intro-to-stereology} focused on accurate (model and assumption-free) quantification of three-dimensional (3D) objects, typically based on their appearance in 2D sections (planes) through the objects. In the biological sciences, these techniques are widely used for making unbiased estimates of arbitrary-shaped (stochastic) objects such as stained cells, blood vessels, region volumes, etc., in tissue sections through a region of interest (ROI).

This fundamental methodology is widely used for evaluating structural changes that occur in diseases, aging, and pharmaceutical interventions, thereby ensuring reliable outcomes. In terms of limitations, stereology is tedious, time- and labor-intensive, …

Bird Strike Hazard Assessment For The Tampa International Airport, Florida, Usa, Yakubu Ogwu Isah

USF Tampa Graduate Theses and Dissertations

Managing wildlife at airports poses a challenge for ensuring safety for aviation traffic. Airports, with their surrounding habitats and infrastructure, serve as attractants for avian species. Threats created by these species have led managers to develop management techniques in and around airports (DeVault et al 2013). One approach is the use of geographic information systems (GIS) for analyzing avian strike data and airport bird surveys. Spatial analysis of strike data identifies species of threat by categorizing strike occurrence, species sizes, phase of flight, and risk of damage. In addition, GIS can be used to map hotspots of bird strikes. These …

Investigating Gulf Coast Aquifer System: Stratigraphy Reconstruction, Inverse Modeling, And Groundwater Stress Assessment, Shuo Yang

LSU Doctoral Dissertations

The Mississippi Embayment aquifer system (MEAS) and the Coastal Lowlands aquifer system (CLAS) provide substantial groundwater resources for human activities in the U.S. Gulf Coastal Plain. However, the overexploitation has led to groundwater depletion in the MEAS and the CLAS, threatening sustainable groundwater use. Such concern highlights the crucial need for an advanced understanding of stratigraphy and groundwater in these aquifer systems, which is essential for effective regional groundwater management. This dissertation presents a comprehensive investigation of MEAS and CLAS in the Louisiana and southwestern Mississippi region, encompassing three fundamental dimensions: stratigraphy reconstruction, groundwater modeling, and groundwater stress assessments. A …

Utilizing Machine Learning Techniques For Accurate Diagnosis Of Breast Cancer And Comprehensive Statistical Analysis Of Clinical Data, Myat Ei Ei Phyo

USF Tampa Graduate Theses and Dissertations

Breast cancer represents a formidable malignancy, presenting a substantial threat to global health and individual well-being. Conventionally, it is widely held that the prognosis for breast cancer patients hinges predominantly upon the timing of diagnosis and the extent of cancer progression, typically delineated by its stage. However, emerging evidence from robust regression and machine learning analyses challenges this prevailing notion. The results indicate that survival months cannot be solely attributed to diagnosis and socio-economic factors. Instead, additional variables such as existing diseases and treatment complexities may contribute to the intricate landscape of breast cancer outcomes.

This research aims to delve …

Predicting Gender Of Author Using Large Language Models (Llms), Satya Uday Sanku

USF Tampa Graduate Theses and Dissertations

The advent of text data from social media, blogs, movie reviews, and other textual sources has opened new avenues for research, particularly in the domain of Author Profiling. Author Profiling helps in Capturing the Stylistic features and also useful for analyzing the required elements in the written text. This Study addresses one of the tasks in Author Profiling which is termed as gender detection or Classification of Gender from Text. The main goal of this research is to obtain valuable and relevant gender characteristics that will accurately classify the Author’s gender of a review extracted from an Anime Review website. …

Interrelationships Among Local Values Of Wet Bulb Globe Temperature, Heat Index, And Adjusted Temperature, Andrea Giraldo

USF Tampa Graduate Theses and Dissertations

Occupational heat stress significantly affects outdoor workers who face challenges due to increased heat exposure. Because of the prevalence of heat illness, it is important to measure heat stress for outdoor workers. Monitoring occupational heat stress most often relies on the Wet Bulb Globe Temperature (WBGT) measure. Heat Index (HI) is a widely used measure to account for air temperature and humidity. Adjusted Temperature (Tadj) considers air temperature, humidity and estimates radiant heat. There is interest in predicting WBGT from HI and HI from WBGT. This study builds on previous USF research by Bernard and Iheanacho and Irvin to evaluate …

Investigating The Causes Of Lake Level Variability On A Modern Carbonate Platform, Natalie M. Salazar

USF Tampa Graduate Theses and Dissertations

Lakes on carbonate islands are known to reduce freshwater lens volumes and alter freshwater lens distribution; however, the magnitude and controlling factors between lake and freshwater lens interactions remain poorly understood. Since freshwater lenses are thin and can be fragmented by lakes in small carbonate islands, it is important to understand the magnitude of exchange between lakes and the freshwater lens to understand potential groundwater depletion. This study utilized high temporal resolution water levels and meteorological data to quantify monthly water budgets for seven lakes on San Salvador Island, The Bahamas. The monthly water budgets accounted for rainfall, potential evaporation, …