Physical Sciences and Mathematics Commons^™

Wavelet Particle Hydrodynamics For Less Smooth Flow, Oddny Brun

Electronic Theses and Dissertations, 2020-

The purpose of this research was to improve the smoothing operation in smoothed particle hydrodynamics, SPH, when the flow of matter is not smooth. Our main focuses are on the kernel selection, identifying the discontinuities in the sequences to be smoothed, and use of the Laplacian as opposed to artificial viscosity for improved physical accuracy. The results show that alternative kernels result in differences in how matter flows. These effects are explained by the kernels' gradient and Laplacian properties. Five alternative kernels were included in our analysis and our SPH-based simulation cases. Further, the sequences to be smoothed by the …

Utilizing High Throughput Computing Techniques For The Predictions Of Spectroscopic Properties Of Astrophysically Relevant Molecules, Brian Ferrari

Electronic Theses and Dissertations, 2020-

Here, we utilize Quantum Chemistry (QC) approaches to predict the structures, vibrational frequencies, infrared intensities and Raman activities of unusual molecular species using the General Atomic and Molecular Structure System (GAMESS(US)) package. A Python-based software, AutoGAMESS, was developed to automate the workflow and take advantage of High Throughput Computing (HTC) techniques enabling the automated generation of spectroscopic data from hundreds of calculations. This approach was utilized to determine these properties for a series of carbon oxides (C2On; n = 3 to 4), anticipated to be produced during the radiation of pure carbon dioxide ices, under conditions relevant to the interstellar …

Nonlinear Light-Matter Interactions In Novel Crystals For Broadband Mid-Infrared Generation, Taiki Kawamori

Electronic Theses and Dissertations, 2020-

Mid-infrared (MIR) laser sources have demonstrated diverse applications in science and technology. For spectroscopy applications, numerous molecules have unique absorption features in this range, and one needs a spectrally broad coherent laser source for parallel detection of mixtures of species. Frequency down-conversion in nonlinear optical materials via second-order nonlinear susceptibility is one of the promising techniques to generate the spectral coverage of more than an octave in the MIR, assisted by emerging novel crystals. The nonlinear light-matter interactions in such special crystals as ZnSe ceramics have not been analyzed. Additionally, through the use of high-intensity few-cycle optical pulses, high-order nonlinear …

Machine Learning Techniques For Topic Detection And Authorship Attribution In Textual Data, Fereshteh Jafariakinabad

Electronic Theses and Dissertations, 2020-

The unprecedented expansion of user-generated content in recent years demands more attempts of information filtering in order to extract high-quality information from the huge amount of available data. In this dissertation, we begin with a focus on topic detection from microblog streams, which is the first step toward monitoring and summarizing social data. Then we shift our focus to the authorship attribution task, which is a sub-area of computational stylometry. It is worth mentioning that determining the style of a document is orthogonal to determining its topic, since the document features which capture the style are mainly independent of its …

Using Iphone Significant Location Data To Improve Air Pollution Exposure Estimation, Elizabeth Eastman

Electronic Theses and Dissertations, 2020-

An accurate estimation of human exposure to ambient air pollution is crucial for air pollution health studies. Time-activity patterns may introduce substantial uncertainties in exposure estimation. As smartphones are becoming increasingly popular and their ownership is becoming ubiquitous in the US. Virtually all smartphones can collect location data, and such data is continuously somewhere. Therefore, it is clear that such stored location data has the potential to be used for characterizing an individual's time-activity patterns for air pollution health studies. However, studies on the accuracy and feasibility of using a smartphone's location data in air pollution exposure estimation are still …

Studying Users Interactions And Behavior In Social Media Using Natural Language Processing, Sultan Alshamrani

Electronic Theses and Dissertations, 2020-

Social media platforms have been growing at a rapid pace, attracting users' engagement with the online content due to their convenience facilitated by many useful features. Such platforms provide users with interactive options such as likes, dislikes as well as a way of expressing their opinions in the form of text (i.e., comments). As more people engage in different social media platforms, such platforms will increase in both size and importance. This growth in social media data is becoming a vital new area for scholars and researchers to explore this new form of communication. The huge data from social media …

Directional Spectral Solar Energy For Building Performance: From Simulation To Cyber-Physical Prototype, Joseph Del Rocco

Electronic Theses and Dissertations, 2020-

The original research and development in this dissertation contributes to the field of building performance by actively harnessing a wider spectrum of directional solar radiation for use in buildings. Solar radiation (energy) is often grouped by wavelength measurement into the spectra ultraviolet (UV), visible (light), and short and long-wave infrared (heat) on the electromagnetic spectrum. While some of this energy is directly absorbed or deflected by our atmosphere, most of it passes through, scatters about, and collides with our planet. Modern building performance simulations, tools, and control systems often oversimplify this energy into scalar values for light and heat, when …

High Spectral Brightness, Broad Area Quantum Cascade Lasers, Enrique Sanchez Cristobal

Electronic Theses and Dissertations, 2020-

Quantum cascade lasers are unipolar semiconductor lasers that offer a unique combination of compact size, high efficiency, high optical power, and flexibility to achieve a targeted emission wavelength with the same laser core material composition, employing so-called bandgap engineering. Since their invention in 1994, watt-level CW power with 5 to 20 % wallplug efficiency was demonstrated for QCLs throughout the entire 4 to 12 µm range, which makes QCLs very attractive for a number of practical applications. Our earlier work on broad-area QCLs emitting in the 4.6 µm to 5.7 µm spectral range demonstrated that CW power scaling with lateral …

Efficient Data Structures For Text Processing Applications, Paniz Abedin

Electronic Theses and Dissertations, 2020-

This thesis is devoted to designing and analyzing efficient text indexing data structures and associated algorithms for processing text data. The general problem is to preprocess a given text or a collection of texts into a space-efficient index to quickly answer various queries on this data. Basic queries such as counting/reporting a given pattern's occurrences as substrings of the original text are useful in modeling critical bioinformatics applications. This line of research has witnessed many breakthroughs, such as the suffix trees, suffix arrays, FM-index, etc. In this work, we revisit the following problems: 1. The Heaviest Induced Ancestors problem 2. …

Spectral Dependence Of Deep Subwavelength Metallic Apertures In The Mid-Wave Infrared, Heath Gemar

Electronic Theses and Dissertations, 2020-

For two decades, extraordinary optical transmission (EOT) has amplified exploration into subwavelength systems. Researchers have previously suggested exploiting the spectrally selective electromagnetic field confinement of subwavelength cavities for multispectral detectors. Utilizing the finite-difference frequency domain (FDFD) method, we examine electromagnetic field confinement in both 2-dimensional and 3-dimensional scenarios from 2.5 to 6 microns (i.e., mid-wave infrared or MWIR). We explore the trade space of deep subwavelength cavities and its impact on resonant enhancement of the electromagnetic field. The studies provide fundamental understanding of the coupling mechanisms allowing for prediction of resonant spectral behavior based on cavity geometry and material properties. …

Quantifiability: Concurrent Correctness From First Principles, Victor Cook

Electronic Theses and Dissertations, 2020-

Architectural imperatives due to the slowing of Moore's Law, the broad acceptance of relaxed semantics and the O(n!) worst case verification complexity of sequential histories motivate a new approach to concurrent correctness. Desiderata for a new correctness condition are that it be independent of sequential histories, compositional over objects, flexible as to timing, modular as to semantics and free of inherent locking or waiting. This dissertation proposes Quantifiability, a novel correctness condition based on intuitive first principles. Quantifiablity is formally defined with its system model. Useful properties of quantifiability such as compositionality, measurablility and observational refinement are demonstrated. Quantifiability models …

Optimizing Mixed Reality Simulation To Support Stem Graduate Teaching Assistants In Developing Student-Centered Pedagogical Skills, Constance Doty

Electronic Theses and Dissertations, 2020-

Physics graduate teaching assistants (GTA) often instruct student-centered lab and recitation sections at large universities, creating the opportunity to positively impact students. However, as STEM GTA professional development varies by institution and discipline, GTAs rarely receive feedback about their teaching. In K-12 teacher preparation, "microteaching", where a teacher teaches a lesson to peers acting as students, is used to provide feedback. Research has demonstrated benefits to microteaching in K-12 teacher and STEM GTA preparation, but practicing teachers find microteaching can lack authenticity. Recently, researchers have explored integrating technology, like simulation, in pedagogy training to provide a more authentic training experience. …

Capsule Networks For Video Understanding, Kevin Duarte

Electronic Theses and Dissertations, 2020-

With the increase of videos available online, it is more important than ever to learn how to process and understand video data. Although convolutional neural networks have revolutionized the representation learning from images and videos, they do not explicitly model entities within the given input. It would be useful for learned models to be able to represent part-to-whole relationships within a given image or video. To this end, a novel neural network architecture - capsule networks - has been proposed. Capsule networks add extra structure to allow for the modeling of entities and has shown great promise when applied to …

The Social And Behavioral Influences Of Interactions With Virtual Dogs As Embodied Agents In Augmented And Virtual Reality, Nahal Norouzi

Electronic Theses and Dissertations, 2020-

Intelligent virtual agents (IVAs) have been researched for years and recently many of these IVAs have become commercialized and widely used by many individuals as intelligent personal assistants. The majority of these IVAs are anthropomorphic, and many are developed to resemble real humans entirely. However, real humans do not interact only with other humans in the real world, and many benefit from interactions with non-human entities. A prime example is human interactions with animals, such as dogs. Humans and dogs share a historical bond that goes back thousands of years. In the past 30 years, there has been a great …

Human Behavior In Domestic Environments: Prediction And Applications, Sharare Zehtabian

Electronic Theses and Dissertations, 2020-

A longstanding goal of human behavior science is to model and predict how humans interact with each other or with other systems. Such models are beneficial and have many applications, including designing and implementing assistive technologies, improving users' experiences and quality of life and making better decisions to create public policies. Behavior is highly complex due to uncertainties and a lack of scientific tools to measure it. Hence prediction of human behavior cannot be 100% accurate. However, prediction is also not hopeless because the biological needs, as well as cultural conventions (for instance, regarding meal times) set the general patterns …

Human-Computer Interaction Research And Education--Crossing Boundaries Between Academic Research And Industry Practices, Yasushi Akiyama

Interface: An International Interdisciplinary Studies Journal

In this paper, I will discuss my own experience and approaches to enhancing students' learning in Human-Computer Interaction (HCI) classes by adopting an interdisciplinary approach that integrates academic research and industry practice. Due to the inherent interdisciplinarity of HCI, and to foster a set of "soft" skills known in Interdisciplinary Studies as the "cognitive toolkit," I invite expertise from the other departments at my university as well as industry professionals to give lectures, facilitate workshops, and oversee projects. These collaborations have produced several insights and have had a positive impact on the participants.

Faculty-Librarian Cooperation For Virtual Stem Based Courses: Creating Successful Learning Experiences For Undergraduate Students At Ucf, Sandy Avila, Nicole Lapeyrouse

Faculty Scholarship and Creative Works

This conference presentation was delivered at the Special Libraries Association annual virtual conference on August 12, 2021.

Session Abstract

In this session, University of Central Florida Chemistry Faculty, Dr. Nicole Lapeyrouse and Science Librarian, Sandy Avila will discuss their transition from in-person instruction to online learning during the pandemic and how their professional collaboration developed instructional resources for student success. Prior to COVID-19, a fruitful cooperative relationship was already in place, but quickly having to pivot to remote teaching and learning allowed for additional opportunities for unique experiences to be created. Those include use of open-educational e-texts, interactive online software …

Sustainability And Hospitality: People, Planet And Prosperity, Alan Fyall

Rosen Research Review

An interview with Jared Meyers, Chairman, Legacy Vacation Resorts, a Certified B Corporation, by Alan Fyall

The Effects Of Water Ice Sublimation On Slope Failures Of Icy Regolith, Christopher Cox, Madison Weinberg, Trisha Joseph

The Pegasus Review: UCF Undergraduate Research Journal

The frost line in a planetary system represents the distance from the central star inside of which conditions are too warm for ice to form, while beyond this line it will be stable. When an icy object passes that line heading toward the Sun it will begin to sublimate and outgas, potentially causing mass loss and surface changes. One example is surface failures, which can lead to material being removed from the object. Evidence of this has been seen on cometary surfaces, where surfaces often show structures that appear to have suffered various mechanical failures like cracking and landslides. By …

13c Chemical Shift Concentration Dependence Of Phenol, Anisole, And Their Sulfur Analogs As A Probe Into Anomalous Reactivity In Electrophilic Aromatic Substitution Reactions, Braxton Lowers, Adam Reed

The Pegasus Review: UCF Undergraduate Research Journal

The ¹³C chemical shift concentration dependence of phenol, anisole, thiophenol, and thioanisole in CDCl₃ was acquired and analyzed over various concentration ranges and reported with the intention of observing the effect of hydrogen bonding on the electron density around aromatic nuclei. Of the para carbon chemical shift concentration dependences observed, phenol exhibited the most significant concentration dependence. Attempts were made to determine the functions describing concentration dependence of the ¹³C chemical shifts observed. Notably, CDCl₃ was found to exhibit relatively nonlinear concentration dependence in the same range as the compounds observed, suggesting that trace impurity and …

Novel Optical Frequency Combs Injection Locking Architectures, Ricardo Bustos Ramirez

Electronic Theses and Dissertations, 2020-

Due to their highly stable timing characteristics, optical frequency combs have become instrumental in applications ranging from spectroscopy to ultra-wideband optical interconnects, high-speed signal processing, and exoplanet search. In the past few years, there has been a necessity for frequency combs to become more compact, robust to environmental disturbances, and extremely energy efficient, where photonic integration shows a clear pathway to bring optical frequency combs to satellites, airships, drones, cars, and even smartphones. Therefore, the development of chip-scale optical frequency combs has become a topic of high interest in the optics community. This dissertation reviews the work made in the …

The Physics Of Nanoaperture Optical Traps: Design, Fabrication And Experimentation, Chenyi Zhang

Electronic Theses and Dissertations, 2020-

Recent progress in nano optics, spurred by progress in nanofabrication, has allowed us to overcome these challenges. We use surface plasmon polaritons to break the optical diffraction limit and squeeze the photon energy into a local hot spot. The small mode volume of a plasmonic antenna or nanoaperature significantly enhances the local field and can be designed to resonate at a desired wavelength. By designing, fabricating, and testing these nanoapertures, I trap single nanoparticles with significantly reduced laser power by measuring the monochromatic transmission change of a resonant aperture. A freely diffused nanoparticle, behaving like a dipole antenna, interacts with …

A Jones Calculus Approach To High-Order Harmonic Generation In Solids, Erin Crites, Shima Gholam-Mirzaei, Zain Khan, Mamta Singh, John E. Beetar

The Pegasus Review: UCF Undergraduate Research Journal

High-order harmonics from bulk solids were first observed in 2011 by focusing an intense mid-infrared laser through a bulk crystal and detecting the harmonics in a transmission geometry. Due to birefringence and possible nonlinear effects in bulk crystal, the polarization state of the laser can change as it propagates through the crystal in this transmission geometry. This can result in harmonic signal generated with an unknown polarization of light, disrupting the signal. Alternatives to bulk crystal, such as a reflection geometry or thin films, are not always ideal – reflection geometry can introduce nonlinear reflection coefficients, while crystalline thin films …

Photoluminescence Properties Of Polycyclic Aromatic Sulfur Heterocycles And Their Sorption And Desorption Onto Microplastics., Sadia Arif

Electronic Theses and Dissertations, 2020-

Polycyclic aromatic sulfur heterocycles (PASHs) are sulfur analogues of polycyclic aromatic hydrocarbons (PAHs) commonly found in environmental samples exposed to oil contamination. The determination of PASHs in complex samples is far more difficult than PAHs because of the sulfur atom in the heterocyclic ring, which increases the total number of possible isomeric compounds. Since their toxicological properties vary considerably from isomer to isomer, the unambiguous determination of specific isomers in environmental samples is crucial for ecotoxicological purposes and human safety. GC-MS has been the primary analytical technique for the determination of PASHs in environmental samples. Unfortunately, as the number of …

Exploring New Materials As Promising Electrocatalysts For The Generation Of A Clean And Renewable Energy Source, Tyler Campbell

Electronic Theses and Dissertations, 2020-

This work presents the research of myself, my advising professor, and our collaborators in first-principles studies of several catalytic materials for improving the efficiency and economics of hydrogen fuel cells, focusing on the oxygen reduction reaction (ORR) at the cathode, CO removal and the hydrogen oxidation reaction (HOR) at the anode, and the redox reactions used for water splitting through photocatalysis. We use a computational design approach to analyze the reaction thermodynamics, applying density functional theory (DFT) for most calculations. We find that, through a subversion of the linear scaling approximation for surface reactivity, an Au monolayer deposited on the …

Development Of Quantitative Intensity-Based Single-Molecule Assays, Benjamin Croop

Electronic Theses and Dissertations, 2020-

Fluorescence microscopy has emerged as a popular and powerful tool within biology research, owing to its exceptional signal contrast, specificity, and the versatility of the various microscope designs. Fluorescence microscopy has been used to study samples across orders of magnitude in physical scale ranging from tissues to cells, down to single-molecules, and as such has led to breakthroughs and new knowledge in a wide variety of research areas. In particular, single-molecule techniques are somewhat unique in their ability to study biomolecules in their native state, which enables the visualization of short-lived interactions and rare events which can be highly relevant …

Directional Link Management Using In-Band Full-Duplex Free Space Optical Transceivers For Aerial Nodes, A F M Saniul Haq

Electronic Theses and Dissertations, 2020-

Free-space optical (FSO) communication has become very popular for wireless applications to complement and, in some cases, replace legacy radio-frequency for advantages like unlicensed band, spatial reuse, and enhanced security. Even though FSO can achieve very high bit-rate (tens of Gbps), range limitation due to high attenuation and weather dependency has always restricted its practical implementation to indoor application like data centers and outdoor application like Project Loon. Building-to-building communication, smart cars, and airborne drones are potential futuristic wireless communication sectors for mobile ad-hoc FSO networking. Increasing social media usage demands high-speed mobile connectivity for applications like video call and …

Analysis Of Sexual Lubricants As A Form Of Trace Evidence For Sexual Assault Cases, Brooke Baumgarten

Electronic Theses and Dissertations, 2020-

A major gap in sexual assault casework is demonstrated when DNA is not recovered. Oftentimes, if DNA evidence is not present on the collection swabs, the sexual assault kit (SAK) is not further analyzed. Due to the "CSI effect," DNA is commonly understood as highly identifiable evidence, potentially leading to increased condom usage to eliminate or reduce DNA transfer during a sexual assault. Therefore, the analysis of condoms and sexual lubricants is pertinent. The purpose of this research is to develop analytical protocols to potentially connect unknown substances recovered in a SAK to known lubricant reference samples. Sexual lubricants were …

Self-Governed Iot Networks: A Blockchain-Based Framework, Mehrdad Salimitari

Electronic Theses and Dissertations, 2020-

In the modern-day, IoT-enabled devices and sensors are growingly deployed in a variety of applications in consumer, commercial, industrial, and infrastructure spaces. Thus, decentralization of such networks for reducing the maintenance and repair costs is significantly gaining attention. In this dissertation, we investigate a variety of mathematical tools and technological advancements to design a secure, fully decentralized, and self-governed IoT network. On this path, the main challenge is ensuring the data integrity in IoT networks, securing the devices against a variety of attack scenarios, and preserving the privacy of the users. We begin by proposing a prospect theoretic method for …

Identification And Detection Of Cosmetics Transferred During Close Personal Attacks, Kandyss Najjar

Electronic Theses and Dissertations, 2020-

New types of trace evidence are necessary to account for the potential lack of evidence found during criminal investigations, due to perpetrators' awareness of common types such as latent prints, hair, and DNA. During cases involving close personal contact, such as sexual assault, perpetrators may not be aware of the possible transfer of cosmetics from or onto the victim or crime scene. Therefore, this project focused on analyzing and developing characterization schemes for cosmetic components, specifically glitter and shimmer particles. Analysis of these particles was performed using various analytical techniques, such as microscopy and spectroscopy techniques, and the developed characterization …