Digital Commons Network^™

2d Materials Based Heterostructures : A Lithography Free Method., Adel Alruqi

Electronic Theses and Dissertations

Many properties of Two-dimensional (2D) materials are vastly different from those of their 3D counterparts. A large family of 2D materials ranging from gapless graphene to metallic NbSe2 (also superconducting), semiconducting MoS2, and insulating hexagonal boron nitride (h-BN) possessing a broad range of exciting new properties have emerged in recent years. Moreover, 2D materials provide the perfect platform to create laterally and vertically stacked heterostructures with intriguing properties. The physics of 2D materials based heterostructures is extremely interesting and novel 2D-heterostructured devices including tunneling diodes, tunneling transistors, photovoltaic cells, and light-emitting diodes have started to emerge. In this work, we …

Studying And Handling Iterated Algorithmic Biases In Human And Machine Learning Interaction., Wenlong Sun

Electronic Theses and Dissertations

Algorithmic bias consists of biased predictions born from ingesting unchecked information, such as biased samples and biased labels. Furthermore, the interaction between people and algorithms can exacerbate bias such that neither the human nor the algorithms receive unbiased data. Thus, algorithmic bias can be introduced not only before and after the machine learning process but sometimes also in the middle of the learning process. With a handful of exceptions, only a few categories of bias have been studied in Machine Learning, and there are few, if any, studies of the impact of bias on both human behavior and algorithm performance. …

Game-Theoretic Frameworks And Strategies For Defense Against Network Jamming And Collocation Attacks, Ahmed Hemida

Electronic Theses and Dissertations

Modern networks are becoming increasingly more complex, heterogeneous, and densely connected. While more diverse services are enabled to an ever-increasing number of users through ubiquitous networking and pervasive computing, several important challenges have emerged. For example, densely connected networks are prone to higher levels of interference, which makes them more vulnerable to jamming attacks. Also, the utilization of software-based protocols to perform routing, load balancing and power management functions in Software-Defined Networks gives rise to more vulnerabilities that could be exploited by malicious users and adversaries. Moreover, the increased reliance on cloud computing services due to a growing demand for …

Light Matter Interaction In Single Molecule Magnets, Rebecca Cebulka

Electronic Theses and Dissertations

This dissertation includes a series of experimental realizations which focus on studying the coupling between photons and single-molecule magnets (SMMs) in both the weak and strong coupling regimes. In the weak coupling regime, the aim is to achieve coherent control over the time evolution of the spin of SMMs while applying rapid microwave pulses at sub-Kelvin temperatures, where polarization of the spin bath may be achieved without large magnetic fields, allowing the suppression of dipolar dephasing. The continuing results of this experiment will be to provide a window into fundamental sources of decoherence in single-crystal SMMs in an energy range …

A Study Of Nonlinear Dynamics Of Eeg Responses To Simulated Unmanned Vehicle Tasks, Ziqing Xu

Electronic Theses and Dissertations

In the contemporary world, mental workload becomes higher as technology evolves and task demand becomes overwhelming. The operators of a system are usually required to complete tasks with higher complicity within a shorter period of time. Continuous operation under a high level of mental workload can be a major source of risk and human error, thus put the operator in a hazardous working environment. Therefore, it is necessary to monitor and assess mental workload. In this study, an unmanned vehicle operation with visual detection tasks was investigated by means of nonlinear analysis of EEG time series. Nonlinear analysis is considered …

Applications Of Deep Learning Models For Traffic Prediction Problems, Rezaur Rahman

Electronic Theses and Dissertations

Deep learning coupled with existing sensors based multiresolution traffic data and future connected technologies has immense potential to improve traffic operation and management. But to deal with complex transportation problems, we need efficient modeling frameworks for deep learning models. In this study, we propose two different modeling frameworks using Deep Long Short-Term Memory Neural Network (LSTM NN) model to predict future traffic state (speed and signal queue length). In our first problem, we present a modeling framework using deep LSTM NN model to predict traffic speeds in freeways during regular traffic condition as well as under extreme traffic demand, such …

An Explainable Sequence-Based Deep Learning Predictor With Applications To Song Recommendation And Text Classification., Khalil Damak

Electronic Theses and Dissertations

Streaming applications are now the predominant tools for listening to music. What makes the success of such software is the availability of songs and especially their ability to provide users with relevant personalized recommendations. State of the art music recommender systems mainly rely on either Matrix factorization-based collaborative filtering approaches or deep learning architectures. Deep learning models usually use metadata for content-based filtering or predict the next user interaction (listening to a song) using a memory-based deep learning structure that learns from temporal sequences of user actions. Despite advances in deep learning models for song recommendation systems, none has taken …

Classifying And Predicting Walking Speed From Electroencephalography Data, Allen Rahrooh

Electronic Theses and Dissertations

Electroencephalography (EEG) non-invasively records electrocortical activity and can be used to understand how the brain functions to control movements and walking. Studies have shown that electrocortical dynamics are coupled with the gait cycle and change when walking at different speeds. Thus, EEG signals likely contain information regarding walking speed that could potentially be used to predict walking speed using just EEG signals recorded during walking. The purpose of this study was to determine whether walking speed could be predicted from EEG recorded as subjects walked on a treadmill with a range of speeds (0.5 m/s, 0.75 m/s, 1.0 m/s, 1.25 …

Student Community Detection And Recommendation Of Customized Paths To Reinforce Academic Success, Yuan Shao

Electronic Theses and Dissertations

Educational Data Mining (EDM) is a research area that analyzes educational data and extracts interesting and unique information to address education issues. EDM implements computational methods to explore data for the purpose of studying questions related to educational achievements. A common task in an educational environment is the grouping of students and the identification of communities that have common features. Then, these communities of students may be studied by a course developer to build a personalized learning system, promote effective group learning, provide adaptive contents, etc. The objective of this thesis is to find an approach to detect student communities …

Mediated Physicality: Inducing Illusory Physicality Of Virtual Humans Via Their Interactions With Physical Objects, Myungho Lee

Electronic Theses and Dissertations

The term virtual human (VH) generally refers to a human-like entity comprised of computer graphics and/or physical body. In the associated research literature, a VH can be further classified as an avatar - a human-controlled VH, or an agent - a computer-controlled VH. Because of the resemblance with humans, people naturally distinguish them from non-human objects, and often treat them in ways similar to real humans. Sometimes people develop a sense of co-presence or social presence with the VH - a phenomenon that is often exploited for training simulations where the VH assumes the role of a human. Prior research …

Decision-Making For Vehicle Path Planning, Jun Xu

Electronic Theses and Dissertations

This dissertation presents novel algorithms for vehicle path planning in scenarios where the environment changes. In these dynamic scenarios the path of the vehicle needs to adapt to changes in the real world. In these scenarios, higher performance paths can be achieved if we are able to predict the future state of the world, by learning the way it evolves from historical data. We are relying on recent advances in the field of deep learning and reinforcement learning to learn appropriate world models and path planning behaviors. There are many different practical applications that map to this model. In this …

Hearing The Voices Of The Deserters: Activist Critical Making In Electronic Literature, Laura Okkema

Electronic Theses and Dissertations

Critical making is an approach to scholarship which combines discursive methods with creative practices. The concept has recently gained traction in the digital humanities, where scholars are looking for ways of integrating making into their research in ways that are inclusive and empowering to marginalized populations. This dissertation explores how digital humanists can engage critical making as a form of activism in electronic literature, specifically in the interactive fiction platform Twine. The author analyzes the making process of her own activist Twine game The Deserters and embeds the project within digital humanities discourses on activism and social justice, hypertext, electronic …

Expanding And Shedding The Self: Processing Selfdom Through Painting, Theresa Lucey

Electronic Theses and Dissertations

The absurd perpetual struggle, although entirely without hope of resolution, is the key to life's meaning, or perhaps, meaninglessness. The artist must work to live and live to work and find their place in an absurd world. Find joy in the questioning act of art making, make no attempt to escape the meaninglessness through pacifism, and face the chaos with awareness. I employ self-portraiture as a means to dig deeply into my experience and response to living. Self-portraiture morphs along with my experiences and keeps a record of my thought patterns. My body of work is the harvest of my …

Seeing The World Differently. An Exploration Of A Professional Development Model Bridging Science And Lay Cultures, Michael D. Garrett

Electronic Theses and Dissertations

This study explores the rationale, efficacy, and social validity of a professional development model designed to move elementary school science activities closer to the practices of working scientists as required by the United States’ “Next Generation Science Standards.” The model is culturally sensitive and aims to create experiences with high subjective task value. The formal theory of change uses scaffolding, Piagetian agency, and Vygotskian learning opportunities to argue that culturally familiar representational tasks in culturally natural intersubjective contexts can lead to work prototypical of scientific modeling under particular facilitation conditions: when participants (a) are allowed free use of their cognitive …

Inversed Learning In An Intermediate Accounting Course, Ashley B. Bentley

Electronic Theses and Dissertations

Students enrolled in accounting courses often struggle because of the complexity of the topic. Accounting instructors have searched for effective means of fostering student success, but the learning process continues to change. Critical thinking and problem solving abilities are vital for students and future professionals. Thus, teaching should not be limited to the transmission of information. By moving the dissemination of basic knowledge outside the classroom inversed learning allows class time for deep dives into complex topics and hands-on activities. Students who are actively involved in learning tend to be more successful in the classroom.

The purpose of this study …

Successful Factors For Native And Community College Transfer Students In Engineering Technology At A Four-Year University, Leendert Craig

Electronic Theses and Dissertations

Students who attend community colleges often transfer to 4-year universities seeking to earn a degree typically not offered at the community college level. Tennessee has 2 programs: the Tennessee Promise and the Tennessee Reconnect programs that offer students tuition-free access to the state’s community college system. Previous studies have been conducted to compare transfer students’ performances to that of native students and typically compared the students in all disciplines. This study seeks to compare transfer students (students who enter the participating university with 40 or more credit hours) to native students (students who initially enrolled or transferred into the 4-year …

Teacher Factors And Student Achievement As Measured By The Act Assessment And Subsequent Teacher Perceptions Of Those Factors, Jessica Weaver

Electronic Theses and Dissertations

The purpose of this quantitative study was to investigate educator factors that have an impact on student achievement and overall school performance as indicated in the American College Test (ACT) scores from the district and the individual schools. Educators from a moderate-sized public school district participated in an anonymous online survey. According to the Tennessee Department of Education (TDOE) Report Card, the district ACT composite is a 20.1 (TDOE, 2018e). Two of the district’s schools’ results are higher than the district composite, while the other five are consistent with or below the district composite. Participants of this study shared their …

An Analysis Of Novice Teachers’ Perceptions Regarding Their Teacher Preparation Program, Professional Support, And The Purpose Of School, Maria Veronica Paz Tagle

Electronic Theses and Dissertations

The purpose of this study was to identify existing relationships between the perceptions of novice teachers regarding their teacher preparation programs, the support given to teachers from their schools, and the purpose of school. The study took place in Northeast Tennessee. Seventeen teachers from three different school systems participated in individual qualitative interviews, which lasted about one hour each.

The finding corroborated the theory analyzed for this study and revealed areas for improvement in all levels of the education system. Teachers suggested meaningful changes to teacher preparation programs, including changes to general prerequisites and reorganizing education programs around meaningful field …

Tennessee High School Counselors' And Dual Enrollment Advisors' Perceptions Of Student Readiness For Dual Enrollment, Aleeta L. Shaw

Electronic Theses and Dissertations

The purpose of this qualitative phenomenological study was to explore Tennessee high school counselors’ and dual enrollment advisors’ perceptions of student readiness for dual enrollment within the context of school, institutional, state, and federal policies as aligned with adolescent development theories in order to inform both policy and practice. Twelve purposely sampled participants from three school districts within the First Tennessee Core Region responded to questions via a recorded phone interview. Participants reflected on the readiness of their students for dual enrollment in the academic, social, and emotional domains. Additionally, participants identified strengths and weaknesses of dual enrollment programs and …

Comparison Of Imputation Methods For Mixed Data Missing At Random, Kaitlyn Heidt

Electronic Theses and Dissertations

A statistician's job is to produce statistical models. When these models are precise and unbiased, we can relate them to new data appropriately. However, when data sets have missing values, assumptions to statistical methods are violated and produce biased results. The statistician's objective is to implement methods that produce unbiased and accurate results. Research in missing data is becoming popular as modern methods that produce unbiased and accurate results are emerging, such as MICE in R, a statistical software. Using real data, we compare four common imputation methods, in the MICE package in R, at different levels of missingness. The …

Ecometric Estimation Of Present And Past Climate Of North America Using Crown Heights Of Rodents And Lagomorphs: With Application To The Middle Miocene Climatic Optimum, Julia Schap

Electronic Theses and Dissertations

Continental scale studies on ungulate crown heights in relation to climate and habitat changes have revealed a correlation between increasing hypsodonty and a shift to more arid environments. Small mammals have been shown to adapt to changing habitats millions of years earlier than larger mammals. In this study I examined fossil localities throughout the last 37 Ma across North America. Diversity of rodents and lagomorphs were analyzed through this time period, with examination of community structure characterized by relative percentages of taxa with different crown heights. Overall, a decrease in precipitation and temperature was found across North America from 37 …

Perfect Double Roman Domination Of Trees, Ayotunde Egunjobi

Electronic Theses and Dissertations

See supplemental content for abstract

Synthesis And Evaluation Of 1,2,4-Oxadiazolidinones: The Search For A Potential Non-Β-Lactam Β-Lactamase Inhibitors., Chimdi Eke Kalu

Electronic Theses and Dissertations

β-lactam antibiotics have been the most widely used drug of choice to combat infectious disease caused by bacteria. Unfortunately, their effectiveness is drastically threatened by bacterial β-lactamases. β-lactamases is responsible for the resistance to most antibiotic drugs. For decades, β-lactam β-lactamases inhibitors have been used to reduce bacterial resistance; however, in this study 1,2,4-oxadiazolidinone derivatives as a non-β-lactam β-lactamases inhibitor against TEM-1 and P99 β-lactamases. The significance of oxadiazolidinone is the prominent five-membered ring scaffold in its structure, which is configurationally stable and present in other biologically active compounds such as linezolid and avibactam. Oxadiazolidinones were synthesized by treating nitrones …

A Comparison Of Standard Denoising Methods For Peptide Identification, Skylar Carpenter

Electronic Theses and Dissertations

Peptide identification using tandem mass spectrometry depends on matching the observed spectrum with the theoretical spectrum. The raw data from tandem mass spectrometry, however, is often not optimal because it may contain noise or measurement errors. Denoising this data can improve alignment between observed and theoretical spectra and reduce the number of peaks. The method used by Lewis et. al (2018) uses a combined constant and moving threshold to denoise spectra. We compare the effects of using the standard preprocessing methods baseline removal, wavelet smoothing, and binning on spectra with Lewis et. al’s threshold method. We consider individual methods and …

A Systematic Assessment Of Socio-Economic Impacts Of Prolonged Episodic Volcano Crises, Justin Peers

Electronic Theses and Dissertations

Uncertainty surrounding volcanic activity can lead to socio-economic crises with or without an eruption as demonstrated by the post-1978 response to unrest of Long Valley Caldera (LVC), CA. Extensive research in physical sciences provides a foundation on which to assess direct impacts of hazards, but fewer resources have been dedicated towards understanding human responses to volcanic risk. To evaluate natural hazard risk issues at LVC, a multi-hazard, mail-based, household survey was conducted to compare perceptions of volcanic, seismic, and wildfire hazards. Impacts of volcanic activity on housing prices and businesses were examined at the county-level for three volcanoes with a …

The Correlation Between The Act, Inc. Explore Test And Student Success In High School Advanced And Advanced Placement Mathematics Courses, Virginia Story

Electronic Theses and Dissertations

The purpose of this study was to compare the relationship between the mathematics portion of the EXPLORE test with students successes in advanced and Advanced Placement(AP) mathematics courses in high school. The data was collected from a rural Tennessee school system consisting of five years of data among graduated seniors. Analysis was completed to determine the difference between the two county high schools in advanced coursework. The findings of this study concluded a positive correlation between EXPLORE scores and the frequency of students who took advanced mathematics courses. Positive correlation between EXPLORE scores and student successes in advanced courses was …

Paleoecology And Land-Use Of Quaternary Megafauna From Saltville, Virginia, Emily Simpson

Electronic Theses and Dissertations

Land-use, feeding habits, and response to seasonality by Quaternary megaherbivores in Saltville, Virginia, is poorly understood. Stable isotope analyses of serially sampled Bootherium and Equus enamel from Saltville were used to explore seasonally calibrated (δ¹⁸O) patterns in megaherbivore diet (δ¹³C) and land-use (⁸⁷Sr/⁸⁶Sr). Overall, this dataset suggests an open forest with relatively constant temperatures year round that were similar to modern conditions. Neither Bootherium or Equus individuals spent a significant amount of time at higher elevations in the nearby Blue Ridge geologic province. These analyses provide a unique perspective on long-term response …

Taking Notes: Generating Twelve-Tone Music With Mathematics, Nathan Molder

Electronic Theses and Dissertations

There has often been a connection between music and mathematics. The world of musical composition is full of combinations of orderings of different musical notes, each of which has different sound quality, length, and em phasis. One of the more intricate composition styles is twelve-tone music, where twelve unique notes (up to octave isomorphism) must be used before they can be repeated. In this thesis, we aim to show multiple ways in which mathematics can be used directly to compose twelve-tone musical scores.

Framework For Modeling Attacker Capabilities With Deception, Sharif Hassan

Electronic Theses and Dissertations

In this research we built a custom experimental range using opensource emulated and custom pure honeypots designed to detect or capture attacker activity. The focus is to test the effectiveness of a deception in its ability to evade detection coupled with attacker skill levels. The range consists of three zones accessible via virtual private networking. The first zone houses varying configurations of opensource emulated honeypots, custom built pure honeypots, and real SSH servers. The second zone acts as a point of presence for attackers. The third zone is for administration and monitoring. Using the range, both a control and participant-based …

Miami-Dade Task Force: A Content Analysis Of How Coastal Communities View Sea Level Rise As A Threat, Francisco Alvaro

Electronic Theses and Dissertations

Sea level rise (SLR) has become a serious threat for coastal communities in recent years. Many communities, including South Florida, are already having the security of their daily lives impacted as climate change causes SLR and other environmental impacts to worsen. This study reviews the Miami-Dade Sea Level Rise Task Force Report to determine how this coastal county government views SLR as a threat. Using mixed content analysis to analyze the report qualitatively and quantitatively, the Task Force's recommendations are categorized based on their focus on security, infrastructure, economics, and the environment. One finds the concerns of the people to …