Digital Commons Network^™

The Implementation And Comparison Of Fuzzy Logic Control Systems To Modern Control Methods On Low-Cost Hardware, Cristian A. Barron

Theses and Dissertations

Modern control engineering provides many options to automate systems for which a mathematical model is required. Another control does not rely on the mathematical model of the system and is known as fuzzy logic control. In this study, a literature review is conducted on existing control systems strategies such as proportional integral and derivative (PID), linear quadratic regulator (LQR), and fuzzy logic controller (FLC), the complexity of the systems they control, and their strengths and weaknesses. In addition, a series of experiments are conducted, both through simulations in MATLAB Simulink and using their implementation using the actual physical hardware to …

Chemical Investigation Of Avocado (Persea Americana) Seed Husk (Testa): A Waste Of Waste, Orlando A. Castillo Scheren

Theses and Dissertations

Food chemistry is a new field in the world and is currently still expanding into the types of market in which it can be tapped into. There are about 1.3 billion tons of food waste produced in 2016 in the world, and food chemistry is going to help get rid of that waste by finding new and exciting applications to the things currently considered as waste. In these products, there might be new and undiscovered drugs that can be used in the market to help treat diseases for which might not have a cure at the current moment. The avocado …

Developing A Uhf/Vhf Phased-Array Satellite Ground Station, Brent K. Cole

Theses and Dissertations

Earth-satellite communications and tracking of spacecraft are accomplished using ground stations. Traditionally, this has been achieved by using a large parabolic antenna or pair of antennas that point at a source of interest and mechanically steer the antenna(s) as the source moves throughout the sky. Phased arrays, which have often been used in radio astronomy, can provide multiple benefits when used as a ground station including fast scanning speeds across the sky, tracking and communication of multiple sources simultaneously, and significant improvements to overall gain, signal-to-noise ratio (SNR), and data bandwidth. This thesis presents a preliminary analysis of a 20-element …

Synthesis, Characterization, And Application Of Meso-Tetraphenyl Metalloporphyrin Photocatalysts Under Visible Light, Alexis Echavarria

Theses and Dissertations

The photocatalytic activity of meso-Tetraphenyl Metalloporphyrins with different metal centers was investigated. The synthesized metalloporphyrin photocatalysts was performed and analyzed using FT-IR spectroscopy, UV-VIS spectroscopy, and powder X-Ray Diffraction analysis. The synthesized TPP crystals were determined to be tetragonal crystal structure and the structure was observed in all synthesized metalloporphyrin catalysts. The Soret (B) bands, Q bands, FT-IR functional groups were identified. Reaction progress was investigated by sampling at intervals of one hour and analysis of the samples was performed using Gas Chromatography-Mass Spectrometry. GC-MS analysis was used to identify the products of the photochemical catalytic redox reactions performed under …

The Relationship Between The 9th Grade State Assessment And Extra Curricular School Activities And Gender For Disadvantaged Hispanic Students In South Texas, Paz Elizondo Jr.

Theses and Dissertations

The purpose of this study is to analyze the relationship between the 9th grade state assessment test scores for Disadvantaged Hispanic students who are taking the English I State of Texas Assessment of Academic Readiness End-of-Course exam. The group analyzed was comprised of the 2016-2017 cohort students from a South Texas High School.

Mexartivist As Resistance Against Media Representation Of Latinxs In The U.S., Jose Garcia Gilling

Theses and Dissertations

MexArtivist comes as a response of wanting to reflect our experiences as Mexicanxs, Latinxs, Chicanxs and Mexican Americans. I've merged my recent academic years, research and knowledge along with my over then years of experience in the film and audiovisual production industry to create the audiovisual group called MexArtivist. Based on research regarding the image, representation, misrepresentation and lack of representation of Latinxs in U.S. films, I present a tangible proposal to try and better this issue.

The Influence Of College Preparation In The Relationship Between High School Socioeconomic Context And College Enrollment, Jeffery J. Huerta

Theses and Dissertations

Recent research has documented that the socioeconomic context of high schools plays a significant role in students’ postsecondary enrollment outcomes (Engberg & Wolniak, 2014; Roderick et al., 2011; Engberg & Wolniak, 2010; Nuñez & Kim, 2012; Hill, 2008; Perna & Titus, 2005; Perna, 2000), with lower college outcomes occurring due to students at lower SES high schools having lower amounts of capital, less access to rigorous curriculum, and more negative peer influences than students at higher SES high schools. However, absent in these studies is whether efforts of comprehensive college preparation were taking place and if such efforts are also …

The Design, Fabrication, And Testing Of A Cooling Garment, Richard James Garza

Theses and Dissertations

The aim of this research is to design a device or technology capable of cooling the user – such as a college student walking to class, for example – in a manner as convenient as putting on a jacket. The idea is to use the peltier effect – a phenomenon in which two dissimilar semi-conductors heat up and cool down with the application of an electric current – as the source of heat absorption used to cool the user. In this research it will be determined whether or not it is feasible to use such a phenomenon to keep the …

Reinforcement Learning Environment For Orbital Station-Keeping, Armando Herrera Iii

Theses and Dissertations

In this thesis, a Reinforcement Learning Environment for orbital station-keeping is created and tested against one of the most used Reinforcement Learning algorithm called Proximal Policy Optimization (PPO). This thesis also explores the foundations of Reinforcement Learning, from the taxonomy to a description of PPO, and shows a thorough explanation of the physics required to make the RL environment. Optuna optimizes PPO's hyper-parameters for the created environment via distributed computing. This thesis then shows and analysis the results from training a PPO agent six times.

Assessing The Performance Of Reconditioned Railroad Tapered-Roller Bearings Used In Freight Rail Service, Veronica Valeria Hernandez

Theses and Dissertations

The rail industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). Bearings that are removed from service are sent to specialized facilities where they undergo a reconditioning process before the bearings can be returned to rail service. The reconditioning process has been used for decades although there has been no previous study on the effectiveness of the reconditioning process on defective bearings that were removed from service. This persuaded the researchers from the University Transportation Center for Railway Safety (UTRCS) …

On Coupled Reaction Diffusion Equations And Their Applications, Juan J. Huerta

Theses and Dissertations

Reaction-diffusion equations are nonlinear partial differential equations that have been used extensively in mathematical modeling. An interesting case in this type of equation is the Fisher-Kolmogorov system, which has been used to study a low-grade glioma, a group of primary brain tumors. In the first part of this thesis, a stochastic version of the Fisher-Kolmogorov system will be studied, and exact and numerical solutions will be presented.

The second part of this thesis will show how the speed of information propagation affects disease spread and vaccination uptake through networks in epidemics. In this model, the information reaches different people at …

Traffic Time Headway Prediction And Analysis: A Deep Learning Approach, Saumik Sakib Bin Masud

Theses and Dissertations

In the modern world of Intelligent Transportation System (ITS), time headway is a key traffic flow parameter affecting ITS operations and planning. Defined as “the time difference between any two successive vehicles when they cross a given point”, time headway is used in various traffic and transportation engineering research domains, such as capacity analysis, safety studies, car-following, and lane-changing behavior modeling, and level of service evaluation describing stochastic features of traffic flow. Advanced travel and headway information can also help road users avoid traffic congestion through dynamic route planning, for instance. Hence, it is crucial to accurately model headway distribution …

Thermal And Spectroscopic Investigations On Polymer-Based Nanofibers, Omosola Oriretan

Theses and Dissertations

Nanofibers of Poly (ethylene oxide), PEO, Poly (vinylpyrrolidone) PVP, Co-nanofiber of PEO-PVP and PEO nanocomposite of various Fullerene compositions were prepared by dissolving PEO, PVP and Fullerene in water. The Fullerene nanoparticles were added to the PEO solutions, the mixtures were homogenized under high power sonication. The PEO solutions, PVP solutions, the co-polymer solutions of PEO-PVP and the PEO -Fullerene solutions were centrifugally spun using Force spinning™ machine. The obtained nanofibers and the nanocomposites were subjected to FTIR analysis, Raman analysis and various heating and cooling cycles with heating and cooling rates ranging from 10C/min to 600C/min using differential scanning …

Chemical Modification And In Silico Validation Of Medicinally Privileged Molecular Scaffolds As Kras And Sars-Cov-2 Protease Inhibitors, Precious M. Okwuchukwu

Theses and Dissertations

Coronavirus disease was declared a global pandemic by WHO in March 2020, cancer is the second leading cause of death by a disease. Several scientists around the world are working relentlessly to discover an effective remedy to eradicate these deadly diseases. A natural polyphenol (magnolol) has been isolated from a tree Magnolia grandiflora (family Magnoliaceae) found on UTRGV campuses. This research is focused on design of a series of chemically modified sulfonyl derivatives based on the isolated magnolol framework and other medicinally privileged molecular scaffolds framework that can effectively bind to the COVID-19 main protease, SARS- CoV-2 3CL protease …

Effects Of Elevated Temperature On 8-Hydroxy-2'-Deoxyguanosine Expression, Dna Damage And Cellular Apoptosis In The American Oyster (Crassostrea Virginica), Md Faizur Rahman

Theses and Dissertations

Global temperature increases due to anthropogenic activities. The effects of rising temperature are well documented in aquatic organisms. The American oyster is an ideal shellfish species to study on global warming and oxidative DNA damage. In this study, We observed the effects of high temperature on heat shock protein-70 (HSP70), 8-hydroxy-2’-deoxyguanosine (8-OHdG), ssDNA, dsDNA, caspase-3 (CASP3), BAX and γH2AX, a molecular marker of DNA damage, protein expressions in gills of oysters. Immunohistochemical results showed that elevated temperatures (28 and 32°C) significantly increased HSP70, 8-OHdG, dsDNA, γH2AX, BAX and CASP3 protein expressions in gills of oysters compare to control (24°C). In …

Bivariate Markov Chain Model Of Irritable Bowel Syndrome (Ibs) Subtypes And Abdominal Pain, Ricardo Reyna Jr.

Theses and Dissertations

Researchers use stochastic models like continuous-time Markov chains (CTMC) to model progression of morbidities of public health impact, like HIV and Hepatitis C. Most of the research in that area is done for a single disease. In this research, we use a bivariate continuous-time Markov chain (CTMC) to model progression of co-morbidities. In particular, we use a bivariate CTMC to model the joint progression of Irritable Bowel Syndrome (IBS) and abdominal pain. Symptoms of IBS are known to change throughout the duration of the disorder. Hence, patients are normally asked to make a journal of the stool type, symptoms, and …

Artificial Intelligence In A Main Warehouse In Panasonic: Los Indios, Texas, Edison Antonio Trejo Hernandez

Theses and Dissertations

The Panasonic Company warehouse is located in Los Indios Texas. The warehouse presents the limitation of the great distances between its headquarters and the Main Warehouse for supplying the branches and main customers, which requires a considerable amount of time to maintain effective communication in the inventory area. In addition, during an online review, it can be confirmed that the website is disabled, contradicting its corporate policy.

The structure of the thesis proposal is arranged in four chapters from the Introduction, Statement of the Problem and Purposes; Previous Studies and Definition of the literature; the Research Methodology and the resources …

Principal Instructional Leadership Behavior As Perceived By Middle School Principals In The Rio Grande Valley Of Texas, Joseph R. Villarreal

Theses and Dissertations

The purpose of this study is to determine which of the 10 leadership functions contained in the PIMRS, as identified by Hallinger (1983), are demonstrated by principals in Rio Grande Valley middle schools that received Texas Education Agency distinctions for closing performing gaps, compared to those middle schools in the Rio Grande Valley that did not. The study aimed to determine if there was a significant difference been the principal instructional leadership behaviors at middle schools recognized for closing performance gaps compared to those that were not recognized. The results showed that there did not exist a significant difference between …

Bioconversion Of Industrial Hemp Biomass For Bioethanol Production: A Review, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Kraig Roozeboom, Donghai Wang

School of Earth, Environmental, & Marine Sciences Faculty Publications

Industrial hemp (Cannabis sativa L.) with robust drought-resistant features has excellent agronomic and pharmaceutical characteristics. As the federal prohibition on hemp cultivation was lifted, its valorization in various aspects is highly required. This review aims to summarize the potential of hemp biomass for bioethanol production. Chemical compositions of hemp biomass were evaluated as compared with those of corn fiber, corn stover, and sorghum bagasse. Several representative pretreatment technologies used for hemp biomass were summarized in terms of sugar recoveries, lignin removal, and sugar and ethanol yields. This review presents numerous technical barriers attributed to insufficient fermentable sugar and ethanol …

Optimizing Energy Power Consumption Of Freight Railroad Bearings Using Experimental Data, Carlos Eliasar Lopez Iii

Theses and Dissertations

Throughout the railway industry, trains use systems that record total energy efficiency of a train but not energy efficiency or consumption by components. Monitoring freight bearing power consumption can support the railroad industry efforts to maintain the railroad economic competitiveness and minimize the environmental impact.

For more than a decade now, the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV) has been collecting power consumption data for railroad bearings under various loads, speeds, ambient temperatures, bearing condition, and bearing classes. Specifically, data such as temperatures, voltages, speed, and load were collected to …

A Targeted Adversarial Attack On Support Vector Machine Using The Boundary Line, Yessenia Rodriguez

Theses and Dissertations

In this thesis, a targeted adversarial attack is explored on a Support Vector Machine (SVM). SVM is defined by creating a separating boundary between two classes. Using a target class, any input can be modified to cross the “boundary line,” making the model predict the target class. To limit the modification, a percentage of an image of the target class is used to get several random sections. Using these sections, the input will be moved in small steps closer to the boundary point. The section that took the least number of steps to cause the model to predict the target …

Motivators And Factors For Career Decision-Making In Speech Language Pathology Students, Ruth Crutchfield, Adriana T. Gomez, Zacarias Olivarez, Celeste N. Gonzalez, Alyssa L. Anglin

Communication Sciences & Disorders Faculty Publications

Career decision-making is a strenuous process that requires an individual to research and determine if the ends of the profession justify its means. Specifically, if the vocation of interest meets specific standards set by an individual. Literature review findings revealed eight subtopics that were salient: influencers/role models, demographics, perception of the profession, social belonging, personality type, curriculum approach, clinical experience and sense of urgency. To achieve an understanding of Communication Sciences and Disorders (COMD) student’s motivators and factors for career decision making, a survey was administered which consisted of 37 questions composed of inquiries regarding demographics, decision making and self-efficacy. …

Infection And Persistence Of Zika Virus In Female Immune-Competent Gray Short-Tailed Opossums (Monodelphis Domestica), Oscar Quintanilla

Theses and Dissertations

Zika virus (ZIKV) is a class IV RNA virus transmitted by Aedes species of mosquitoes. It produces flu-like symptoms, but recent studies have associated additional, more severe pathologies with ZIKV like microcephaly. Currently, no effective treatment options or vaccines exist. This is partly due to limitations of current animal models. Monodelphis domestica (the gray short-tail opossum) may serve as a proper model for ZIKV research. Here we test the susceptibility of M. domestica to ZIKV infection. Female, immune-competent subjects were injected with live ZIKV and analyzed serologically and histologically for evidence of ZIKV replication. ELISAs performed on sera confirmed that …

Total Synthesis Of Cytotoxic Mansouramycins From Amino Acids, Beatriz Gamez

Theses and Dissertations

Natural products produced by plants, animals, and microorganisms are of significant importance in chemistry for being major sources of molecular scaffolds essential for new drug discovery. Mansouramycins are cytotoxic bioactive compounds containing isoquinoline skeletons with substituents on the quinone and pyridine rings that may be difficult to synthesize. Synthetic processes exist for compounds B and D, however, there exists an absence of simple synthetic approaches to all four alkaloids.

This project aims to provide a general total synthetic pathway to Mansouramycins A—D from amino acids for possible use in cancer treatment via these isoquinolinequinones. Preliminary experimentation suggests there may be …

A Python-Based Brain-Computer Interface Package For Neural Data Analysis, Md Hasan Anowar

Theses and Dissertations

Anowar, Md Hasan, A Python-based Brain-Computer Interface Package for Neural Data Analysis. Master of Science (MS), December, 2020, 70 pp., 4 tables, 23 figures, 74 references.

Although a growing amount of research has been dedicated to neural engineering, only a handful of software packages are available for brain signal processing. Popular brain-computer interface packages depend on commercial software products such as MATLAB. Moreover, almost every brain-computer interface software is designed for a specific neuro-biological signal; there is no single Python-based package that supports motor imagery, sleep, and stimulated brain signal analysis. The necessity to introduce a brain-computer interface package that …

Neural Network Development In An Artificial Intelligence Gomoku Program, David Garcia

Theses and Dissertations

The game of Gomoku, also called Five in a Row, is an abstract strategy board game. The Gomoku program is constructed upon an algebraic monomial theory to aid values for each possible move and estimate chances for the artificial intelligence program to accomplish a winning path for each move and rounds. With the utilization of the monomial theory, winning configurations are successfully converted into monomials of variables which are represented on board positions. In the artificial intelligence program, an arduous task is how to perform the present configuration of the Gomoku game along with the past moves of the two …

The Relationship Between Academic Performance And Student Mobility, Gender, Ethnicity, Socioeconomic Status And Number Of Moves, Juan C. Garza

Theses and Dissertations

This study analyzes the relationship between student mobility, reading and math scores, gender, ethnicity, socioeconomic status (SES), and the number of moves by students during their academic years. Data were taken from four different high schools during the 2015-2016, 2016-2017, and 2017-2018 school years. The purpose of this study was to determine if student mobility when considering gender, ethnicity, SES, and number of moves impact a student’s reading and math scores. The study will provide educational leaders, community, and parents with valuable data to make informed decisions with regards to instructional adjustments and school changes for mobile students. The null …

A Predictive Analytics Approach To Building A Decision Support System For Improving Graduation Rates At A Four-Year College, Xuan Wang, Helmut Schneider, Kenneth R. Walsh

Information Systems Faculty Publications

Although graduation rates have interested stakeholders, educational researchers, and policymakers for some time, little progress has been made on the overall graduation rate at four-year state colleges. Even though selective admission based on academic indicators such as high school GPA and ACT/ SAT have widely been used in the USA for years, and recent statistics show that less than 40% of students graduate from four-year state colleges in four years in the US. The authors propose using an ensemble of analytic models that considers cost as a better form of analysis that can be used as input to decision support …

Existence And Stability Of The Doubly Nonlinear Anisotropic Parabolic Equation, Huashui Zhan, Zhaosheng Feng

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, we are concerned with a doubly nonlinear anisotropic parabolic equation, in which the diffusion coefficient and the variable exponent depend on the time variable t. Under certain conditions, the existence of weak solution is proved by applying the parabolically regularized method. Based on a partial boundary value condition, the stability of weak solution is also investigated.

Functional Kernel Density Estimation: Point And Fourier Approaches To Time Series Anomaly Detection, Michael R. Lindstrom, Hyuntae Jung, Denis Larocque

School of Mathematical & Statistical Sciences Faculty Publications

We present an unsupervised method to detect anomalous time series among a collection of time series. To do so, we extend traditional Kernel Density Estimation for estimating probability distributions in Euclidean space to Hilbert spaces. The estimated probability densities we derive can be obtained formally through treating each series as a point in a Hilbert space, placing a kernel at those points, and summing the kernels (a “point approach”), or through using Kernel Density Estimation to approximate the distributions of Fourier mode coefficients to infer a probability density (a “Fourier approach”). We refer to these approaches as Functional Kernel Density …