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Wavelet Particle Hydrodynamics For Less Smooth Flow, Oddny Brun
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
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
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
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
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 …
Directional Spectral Solar Energy For Building Performance: From Simulation To Cyber-Physical Prototype, Joseph Del Rocco
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
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
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
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
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
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. …
Human Behavior In Domestic Environments: Prediction And Applications, Sharare Zehtabian
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 …
The Social And Behavioral Influences Of Interactions With Virtual Dogs As Embodied Agents In Augmented And Virtual Reality, Nahal Norouzi
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 …
Studying Users Interactions And Behavior In Social Media Using Natural Language Processing, Sultan Alshamrani
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 …
Capsule Networks For Video Understanding, Kevin Duarte
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 …
Novel Optical Frequency Combs Injection Locking Architectures, Ricardo Bustos Ramirez
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
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 …
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
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
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
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
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
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
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 …
A Deep Learning Approach For Learning Human Gait Signature, Alexander Matasa
A Deep Learning Approach For Learning Human Gait Signature, Alexander Matasa
Electronic Theses and Dissertations, 2020-
With advancements in biometric securities, focus has increased on utilizing gait as a means of recognition. Gait describes the unique walking pattern present in humans and has shown promising results in person re-identification tasks. Unlike other biometric features, gait is unique in that it is a subconscious behavior minimizing the risk of purposeful obfuscation. In this research, we first cover supervised approaches showing that current methods fail to learn a unique signature that describes the motion of a subject. Rather they extract frame-based feature information which is then aggregated. While these methods have shown to be effective, they do not …
Enhancement And Evaluation Of Proton Pencil Beam Spot Placement Algorithms, Mahboob Ur Rehman
Enhancement And Evaluation Of Proton Pencil Beam Spot Placement Algorithms, Mahboob Ur Rehman
Electronic Theses and Dissertations, 2020-
Intensity modulated proton therapy (IMPT) in the form of pencil beam scanning (PBS) has shown improvement in treatment plan quality as compared to conventional proton and photon-based radiotherapy techniques. However, in IMPT maintaining a sharp lateral dose falloff is crucial for sparing organs at risk (OARs), especially when they are in close proximity to the target volume. The most common approach to improve lateral dose falloff is through the use of physical beam shaping devices, such as brass apertures or collimator-based systems. This work has shown that IMPT can be further improved by implementation of advanced spot placement techniques by …
Secure And Trustworthy Hardware And Machine Learning Systems For Internet Of Things, Shayan Taheri
Secure And Trustworthy Hardware And Machine Learning Systems For Internet Of Things, Shayan Taheri
Electronic Theses and Dissertations, 2020-
The advancements on the Internet have enabled connecting more devices into this technology every day. This great connectivity has led to the introduction of the internet of things (IoTs) that is a great bed for engagement of all new technologies for computing devices and systems. Nowadays, the IoT devices and systems have applications in many sensitive areas including military systems. These challenges target hardware and software elements of IoT devices and systems. Integration of hardware and software elements leads to hardware systems and software systems in the IoT platforms, respectively. A recent trend for the hardware systems is making them …
Spatial-Temporal Representation Learning: Concepts, Algorithms And Applications, Pengyang Wang
Spatial-Temporal Representation Learning: Concepts, Algorithms And Applications, Pengyang Wang
Electronic Theses and Dissertations, 2020-
Recent years have witnessed the flourish of Internet-of-Things (IoT), in which sensors connect spatial entities to constitute complex Cyber-Physical Systems (CPSs). In this setting, spatial-temporal data becomes increasingly available. Mining spatial-temporal data can reveal holistic user and system structures, dynamics, and semantics of the underlying CPSs, including identifying trends, forecasting future behavior, and detecting anomalies. However, obtaining effective representations over spatial-temporal data remains a big challenge for the following reasons: (1) on the one hand, traditional manual feature design is labor-intensive and time-consuming facing the complex and huge volumes of spatial-temporal data; (2) on the other hand, as an emerging …
Biophysical Analysis Of The Structure And Aggregation Of Amyloid Beta Peptide, Faisal Abedin
Biophysical Analysis Of The Structure And Aggregation Of Amyloid Beta Peptide, Faisal Abedin
Electronic Theses and Dissertations, 2020-
Alzheimer's disease (AD) is the major cause of dementia and is characterized by neuronal death and brain atrophy. The amyloid ß (Aß) peptide is tightly associated with neuronal dysfunction during AD, but the molecular mechanism underlying the neurotoxic effect of Aß is poorly understood. Extracellular fibrillar deposits (plaques) of Aß were initially believed to be the cause of AD, but currently there is overwhelming evidence that the prefibrillar Aß oligomers are the major toxic entities. Structural characterization of Aß oligomers and fibrils is important for understanding the structural features determining the toxic potency of the peptide. This project has studied …
Visual Learning Beyond Human Curated Datasets, Muhammad Abdullah Jamal
Visual Learning Beyond Human Curated Datasets, Muhammad Abdullah Jamal
Electronic Theses and Dissertations, 2020-
The success of deep neural networks in a variety of computer vision tasks heavily relies on large- scale datasets. However, it is expensive to manually acquire labels for large datasets. Given the human annotation cost and scarcity of data, the challenge is to learn efficiently with insufficiently labeled data. In this dissertation, we propose several approaches towards data-efficient learning in the context of few-shot learning, long-tailed visual recognition, and unsupervised and semi-supervised learning. In the first part, we propose a novel paradigm of Task-Agnostic Meta- Learning (TAML) algorithms to improve few-shot learning. Furthermore, in the second part, we analyze the …