Digital Commons Network^™

Government Documents For All: U.S. Supreme Court Opinions, Tim Dodge

The Southeastern Librarian

No abstract provided.

The Future Of Brain Tumor Diagnosis: Cnn And Transfer Learning Innovations, Shengyuan Wang

Mathematics, Statistics, and Computer Science Honors Projects

For the purpose of improving patient survival rates and facilitating efficient treatment planning, brain tumors need to be identified early and accurately classified. This research investigates the application of transfer learning and Convolutional Neural Networks (CNN) to create an automated, high-precision brain tumor segmentation and classification framework. Utilizing large-scale datasets, which comprise MRI images from open-accessible archives, the model exhibits the effectiveness of the method in various kinds of tumors and imaging scenarios. Our approach utilizes transfer learning techniques along with CNN architectures strengths to tackle the intrinsic difficulties of brain tumor diagnosis, namely significant tumor appearance variability and difficult …

Genetics Of Lrg1 And Its Association With The Cardiometabolic Risk Traits In Mexican American Children And Adolescents, Aaron Rene Reyna

Theses and Dissertations

Leucine-rich alpha-2-glycoprotein 1 (LRG1) has become a major topic of research due to an increasing number of studies demonstrating its unique role in the pathogenesis of multiple human diseases including diabetes and cardiovascular disease. LRG1 has recently been identified as an adipokine, a signaling molecule secreted by adipose tissue. Furthermore, it has been correlated with intercellular signaling that promotes diet-induced hepatosteatosis and insulin resistance in mice. In this study, LRG1 serum concentrations were measured in a family-based cohort of 571 non-diabetic Mexican American children and adolescents aged 6-17 years old (mean age = 11.76 years and females = 48.2%) to …

Foxo4 Impacts Akt In Glioblastoma Multiforme, David Uribe

Theses and Dissertations

Glioblastoma Multiforme (GBM) is an aggressive cancer with patients surviving 13 months on average after diagnosis. The PI3K-PKB/AKT pathway is conserved from flies to mammals. The PI3K signaling pathway aids in the growth and survival of tumor cells. Forkhead box transcription factors subclass O (FOXO1, FOXO3, and FOXO4) act as tumor suppressors in some contexts. In GBM, our group and others showed that FOXO transcription factors drive stem gene expression to promote growth and survival. We disrupted the FOXO4 gene in U87MG cells using CRISPR Cas9 genome editing and performed RNA-seq to identify targets of this …

Development And Application Of Environmental Dna (Edna) Techniques To Detect Rough-Footed And Yellow Mud Turtles: A Seasonal Field Study To Detect Turtle Edna, Sakib Tahmid Rishan

Theses and Dissertations

The application of environmental DNA (eDNA) has improved the ability of humans to detect the existence and geographical distribution of aquatic organisms. The present study highlights the development and application of eDNA techniques to detect rough-footed mud turtles and yellow mud turtles in different areas in Texas. Both mud turtle species were successfully detected in lakes/resacas using direct eDNA sampling techniques. Moreover, passive eDNA sampling techniques were conducted using different membrane filters to detect mud turtle species. The findings indicated that only the mixed cellulose esters (MCE) filter membranes effectively identified eDNA of yellow mud turtles in the fall, but …

Effects Of Nitrogen Or Phosphorus Depletion On Lipid Production In Bracteacoccus Sp. And Tetrastrum Sp., Cassandra J. Po

Theses and Dissertations

As global energy demands have risen in the past decades, various species of microalgae have been chosen and used as sources of lipids for third-generation biofuel. I selected two species of green microalgae, Bracteacoccus sp. and Tetrastrum sp., from isolates from South Texas to determine their potential as sources of biofuel. For comparison, Chlamydomonas reinhardtii was used as a model organism. To evaluate lipid productivity under different nutrient regimens, the microalgae were grown in nutrient-replete growth media until the population had reached the end of the logarithmic phase (roughly 14 days), and then transferred into growth media depleted of nitrogen …

Development Of A More Sustainable High And Ultra-High-Performance Concrete, Enrique Chirino Andalco

Theses and Dissertations

The urgent need to address climate change and environmental damage presents humanity with significant challenges that must be tackled quickly, not acting promptly will result in irreversible consequences, such as extreme weather events, public health risks, and water shortages, among other impacts.

Due to its enormous size and variety of uses, the construction industry is a key factor in addressing the climate challenge. Specifically, concrete as the most used construction material in the world is a good target for developing innovative and Sustainable improvements to reduce environmental impacts.

Using by-products from other industries in concrete manufacturing is a common and …

Care-Teach: Proposing An Open-Source Approach To Personalized Learning, Jaime Augusto Alvarez Perez

Theses and Dissertations

Care-Teach is an algorithmic educational model that provides teachers and educators with the tools to create interactive, text-based lessons that address a student’s need for continuity and reinforcement. Care-Teach is built around two core components: a Student Behavior Profile and the Skill Tree. These models work together to give each student a personalized learning experience that reinforces their pre-existing strengths and inclinations. The Student Behavior Profile model keeps track of a learner’s inclinations and mood, utilizing metrics such as average response time and accuracy to categorize opportunities for educator involvement. The Skill Tree is an organizational …

The Impact Of Culture On Firm Performance: A Study On The Effect Of Respect, Teamwork, Innovation, Quality And Integrity On Corporate Profitability, Raphael Mwangi Wambugu

Theses and Dissertations

This thesis investigates the intricate relationship between organizational culture and firm performance, focusing on specific cultural dimensions of respect, teamwork, innovation, quality, and integrity as possible determinants of firm performance. The main objective is to find out the impact of these cultural elements on the dependent variable, return on assets (ROA).

As organizations strive for sustained success and competitive advantage, understanding the interplay between culture and financial performance becomes important. The cultural variable of respect is examined as a catalyst for fostering diverse perspectives and collaborative interactions within the organization. Teamwork is analyzed for …

Machine Learning Predictive Models For Load Identification Of Railroad Bridges Subjected To Train-Induced Vibration, Md Masnun Rahman

Theses and Dissertations

The U.S. rail network is among the world's largest, safest, and most efficient. However, many its railway bridges, which play an essential role in its connectivity, are over 100 years old, showing signs of structural deterioration exceeding their practical service life. The increased weight and speed of modern trains also pose a risk to these bridges. Traditional load identification and monitoring technologies like Weigh-in-Motion (WIM) systems are rarely used on railway bridges due to their cost and practical limits. This thesis explores a cost-effective approach to utilize vibration sensors on railway bridges to identify and predict train load features (speed …

Cultural Norms And The Expression Of Affection In Nigerian Yoruba Families, Tolulope G. Banjo

Theses and Dissertations

Affectionate behaviors have biological and physiological implications for humans. Affectionate communication encompasses behaviors that convey affection to the senders and receivers. The purpose of this qualitative study was to investigate the role of culture and cultural traditions in the expression of affectionate behaviors among members of the Nigerian Yoruba family. Two focus groups were conducted in which participants (18-39 years of age) identified the affectionate behaviors they use in their families. Participants also shared how they perceived their culture playing a role in their affectionate communication. The findings revealed 18 categories of affectionate behaviors used by Nigerian Yoruba …

Corre Y Se Va: A Collection Of Ramblings, Daniella Arredondo

Theses and Dissertations

This thesis explores womanhood, death, and life writings. Through various pieces of nonfiction writings and poetic writings, this thesis reacts to each theme by making a personal connection to certain moments in the narrator’s life. From the Me-Too moment to a tonsil removal, the narrator situates the thesis as a reactive piece to works like “Borderlands/La Frontera” by Gloria Anzaldúa, nonfiction works, like Chanel Miller’s “Know My Name,” and various news articles around events that relate to each theme. The selections of the themes stem from Loteria, a popular bingo-like game within Hispanic culture. The use of these images creates …

In Absentia, Noreen M. Graf

Theses and Dissertations

In Absentia is a collection of short creative pieces that includes short stories, flash fiction, essay, and comics. The critical introduction aims to place my work into the ongoing dialog surrounding the accelerated portrayal of unlikable female protagonists in contemporary literary fiction.

Model-Based And Model-Free Control Approaches In Subgrids: A Conceptual Review Of Control Strategies In Microgrids, Omobolade H. Abioye

Theses and Dissertations

Increased reliance on the power grid and concerns over climate change issues have resulted in the rapid adoption of renewable energy technologies. Consequently, it is necessary to consider how renewable energy resources are combined and controlled. The microgrid serves as the control center for distributed energy resources. This thesis paper introduces the microgrid elements and framework, its control strategies highlighting frequency and voltage control, and the prospects of artificial intelligence for control, considering two significant approaches. Key components of sub grids like the energy management system (EMS) and energy storage systems (ESSs) are discussed, and lastly, the …

Particle Swarm Optimization For Training Quadrotor Pid Controller, Eric Xavier Rodriguez

Theses and Dissertations

The objective of this research is to establish a fundamental approach to tuning PID (Proportional-Integral-Derivative) parameters for a simulated quadrotor drone. Implementing a PID controller for autonomous flight provides a straightforward and efficient method for monitoring and correcting robotic movement based on the robot's current state. However, applying a PID approach to a quadrotor's flight controller poses challenges, such as assigning multiple parameters to control an inherently under-actuated system. This includes the need to find optimal parameter values that reduce the likelihood of large overshoots and lengthy adjustment times. Ineffectively tuning PID parameters can have detrimental effects on autonomously …

The Impracticality Of Silk, Jo A. Reyes

Theses and Dissertations

In the impracticality of silk, the author examines and critiques the world through poetry and prose poetry, specifically addressing gender, sexuality, relationships, the borderlands, and canonized art as they view it to foment a new understanding and voice during a time of societal and personal shifts. Further complicating the author’s understanding are questions around desire both within reclaimed sensuality and within Audre Lorde’s larger understanding of desire as foundational and necessary in creation and liberation, and Gloria E. Anzaldúa’s use of autohistoria-teoria and her work within borderlands as ways toward reevaluating and reclaiming identity and place in the larger world. …

Rsm For The Optimization Of Selective Laser Melting Process Parameters For Manufacturing Initial Layers Of Horizontal Overhang Structures, Prince Yaw Asamani

Theses and Dissertations

While prevalent in 3D printed objects, overhang features are difficult to print with selective laser melting due to the limitation of a purely vertical laser. To address this issue, overhang features are typically built on temporary supports, which are removed following printing. However, this results in wasted material and longer production time. Several authors have studied printing overhangs without support structures. However, there has not been a systematic approach to studying the effect of multiple process parameters on the quality of a printed overhang. This thesis investigates the effect of laser power, scanning speed, and hatch distance on the surface …

Bayesian Estimation Of Reproduction Numbers From Distributions Of Outbreaks Sizes: Branching Process Approach, Alberta Araba Johnson

Theses and Dissertations

The Generalized Poisson distribution is useful in modeling epidemiological processes as a branching stochastic processes problem. Our goal is to construct accurate and reliable estimators for the reproduction number (R0) (i.e., the number of secondary infections), particularly in the context of disease outbreaks modeled by a Galton-Watson process. Towards this goal, we construct the classical Bayes estimator, the Maximum Likelihood estimator, and the Empirical Bayes (EB) estimator under the Square Error Loss function in Chapter II. We prove that the Empirical Bayes estimator is asymptotically optimal and estimate the rate of convergence. We then proceed to monotonize the Empirical Bayes …

Variational Bias Sampling For Collaborative Filtering Recommender Systems, Prisca Stephens

Theses and Dissertations

Advancements in digitalization has yielded enormous growth of data on online platforms, overwhelming users with multitude of options to choose from. Recommender systems narrow down these options to a few relevant ones thereby facilitating the decision-making processes for users. This study presents a framework for integrating variational bias sampling into model-based collaborative filtering techniques for recommender systems. Variational bias sampling is a novel and unique way to account for random factors that affect explicit ratings in collaborative filtering recommender systems. A Gaussian distribution is used to model all the possible random factors that could affect ratings. Sampling user and item …

Mitigation Methods For Instrumental Artifacts In Gravitational Wave Data, Raghav Girgaonkar

Theses and Dissertations

Strain data from ground-based gravitational wave detectors are regularly affected by instrumental artifacts known as glitches. Such glitches form the background of false alarms in the detection of gravitational waves from compact binary coalescences, in-turn reducing search sensitivity. If left unaccounted, these glitches along with other non-stationarity may also contribute towards a corrupted representation of the statistical properties of detector noise, subsequently affecting parameter estimation for detected gravitational wave candidates. Therefore, effective data analysis methods to veto glitches and identify non-stationarities in detector data are crucial to enhancing the sensitivity of a gravitational wave search. In this thesis, we …

Conditional Constrained And Unconstrained Quantization For A Uniform Distribution On A Hexagon, Christina Hamilton

Theses and Dissertations

In this thesis, we have considered a uniform distribution on a regular hexagon and the set of all its six vertices as a conditional set. For the uniform distribution under the conditional set first, for all positive integers n ≥ 6, we obtain the conditional optimal sets of n-points and the nth conditional quantization errors, and then we calculate the conditional quantization dimension and the conditional quantization coefficient in the unconstrained scenario. Then, for the uniform distribution on the hexagon taking the same conditional set, we investigate the conditional constrained optimal sets of n-points and the conditional constrained quantization errors …

Soil Carbon Sequestration Efforts In Arid And Semi-Arid Climates Under Conservation Agriculture And Reforestation, Samantha Lynn Colunga

Theses and Dissertations

Soil organic carbon (SOC) plays a vital role in the global carbon cycle and aids in climate change mitigation. However, deforestation and intensive agricultural practices threaten topsoil and carbon (C) pools through soil disturbances releasing vast amounts of carbon dioxide (CO2) by enhancing the decomposition of organic materials. Degraded soils typically lack stable aggregates, nutrient and water retention, and overall low fertility. In arid and semi-arid regions, soils are in an even more dire situation, as low precipitation and high temperatures slow down the accumulation of SOC. This thesis has two objectives: 1) to evaluate whether conservation tillage practices increase …

A Descriptive Exploration Of Selected Employment Barriers And Supports For Individuals With Visual Impairments In Bangladesh, Mohammed Mozadded Hossen

Theses and Dissertations

Employment is crucial for individuals with disabilities, including those with visual impairments, as it facilitates financial independence, promotes social inclusion, enhances the quality of life, and enables the utilization of valuable job-related skills. However, some barriers obstruct opportunities for employment for individuals with visual impairments, which affect different areas of their lives. This dissertation investigated the employment barriers, supports, and outcomes for individuals with visual impairments in Bangladesh, with an aim to understanding the factors that impacted employment outcomes for individuals with visual impairment, including access to education and training, availability of employment supports …

How Mathematics Instructors Foster The Development Of Black Students' Mathematics Identity In Undergraduate Active Learning Mathematics Courses, Ashly J. Olusanya

Theses and Dissertations

Black students must overcome unique challenges to succeed in mathematics. Educators are tasked with identifying equitable teaching practices to support these students. Active learning (AL) is a teaching pedagogy that engages students in rigorous mathematical activities and encourages student participation. This research study will explore the professors’ beliefs about how students learn mathematics and why they use active learning in their collegiate mathematics courses. The study explores the connections between these beliefs and their reported use of instructional practices. The study also identifies the instructors’ beliefs about developing students’ mathematics identities, particularly their Black …

Exploring Equity In Biliteracy Development In A Two-Way Dual Language Program, Dalila Ochoa

Theses and Dissertations

This qualitative exploratory study aimed to better understand how biliteracy is conveyed to native English speakers in order for them to acquire a second language, Spanish in a two-way dual language program. The study uses the theoretical framework of Jose Medina’s C6 Biliteracy Framework (2019) and research from Kathy Escamilla (2014). The research questions that guided this study were: (1) What type of instructional methods are the bilingual certified teachers utilizing to support Spanish development for native English students in a two-way dual language program? (2) How are bilingual teachers tracking the progress …

A Multivariate Analysis Of The Gravitational Wave Signal Landscape From Core Collapse Supernovae, Raul Alberto Espinosa Perez

Theses and Dissertations

Core collapse supernovae (CCSN) are highly anticipated sources of gravitational waves (GW) during the on-going fourth observation run (O4) of GW detectors like LIGO and the future observation runs. The GW signal from the CCSN cannot be modeled mathematically. Several groups around the world have engaged in simulation of the predicted GW signals from CCSN sources. These simulations are carried out in supercomputers, and they incorporate general relativity, hydrodynamics, neutrino physics, mass and angular momentum of the stellar progenitor and nuclear equations of state (EoS). The output consists of simulated signals with varying duration, peak frequency, GW energy and time-frequency …

A Study On A Vector Complex Modified Korteweg-De Vries Equation, Changyan Shi

Theses and Dissertations

In this thesis, we systematically study a vector complex modified Kordeweg-de Vries equation by combining Hirota's bilinear method and the the Kadomtsev–Petviashvili (KP) reduction method. This vector nonlinear equation is a multi-component generalization of the well-known modified Kordeweg-de Vries (mKdV) equation and can be reduced to the known Hirota equation, Sasa-Satsuma (SS) equation, Sasa-Satsuma-mKdV equation as well as coupled Sasa-Satsuma equation. First, we bilinearize the vector complex mKdV equation under both the zero and nonzero boundary conditions by introducing auxiliary tau functions. Then, starting from two sets of bilinear equations of multi-component KP hierarchy and single-component KP-Toda …

Uncovering Insights On Remote Learning Through A Critical Discourse Analysis Of Tweets At The Start Of The Pandemic In The United States, Douglas Wayne Bridges

Theses and Dissertations

This dissertation examines the discourses surrounding remote learning during the initial stages of the COVID-19 pandemic through Twitter conversations. Employing a Critical Discourse Analysis informed by Michel Foucault’s theories of discourse and power, this study explores how the pandemic has transformed educational interactions over social media platforms. It particularly focuses on the relationships between language, power, and social structures, highlighting the transformative potentials of remote learning amidst a global crisis.

The research reveals how discourse on Twitter reflects broader societal and cultural dynamics, serving as a microcosm of the shifts within the educational sector. Analysis of Twitter threads, retweets, and …

The Perspectives Of Using Desmos For Students’ Conceptual Understanding And Procedural Fluency To Solve Linear Equations, Larmel Dimatulac Madrilejos

Theses and Dissertations

The study examines the perspectives of using the Desmos calculator of Algebra I students' conceptual understanding and procedural fluency to write, graph, and solve linear equations in Algebra I STAAR. While the students have continuously used technology for mathematics assessment, emergent bilingual students in South Texas still need help passing high-stakes testing. The framework of the study is grounded in the theory of mathematical education (knowledge of mathematics educators to teach), the theory of mathematical learning (understanding how students learn mathematics), and social constructivism. The study seeks ways to teach all students, mainly the minority, to learn …

Synthesis Of Nano-Microstructured Barium Titanate (Batio3) Incorporated In Pvdf-Hfp/Peo For Sustainable And Green Energy Generation, Rigobert Ybarra Jr.

Theses and Dissertations

The global reliance on fossil fuels and natural gas, has largely dominated the energy production field, but due to finite resource depletion and escalating greenhouse gas emissions, the immediate exploration of sustainable energy alternatives to mitigate climate change and ensure resource security has been a major concern. There has been extensive research into other more renewable methods of energy production such as wind and hydropower. Of these current energy generation types there are many areas of untapped potential from the mechanical movements generated ambiently not only in the large scale of power generation but also on a smaller scale. The …