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Articles 1 - 30 of 274
Full-Text Articles in Physical Sciences and Mathematics
Florida's Vanishing Heritage: Climate Risk And Adaptation At Florida Heritage Sites, Levi Watson
Florida's Vanishing Heritage: Climate Risk And Adaptation At Florida Heritage Sites, Levi Watson
Electronic Theses and Dissertations, 2020-
This thesis examines history and preservation at coastal cultural heritage sites threatened by climate change and explores climate adaptation strategies at two sites on Florida's Atlantic coast. Current climate change models indicate the planet may see as much as 1.1 meters, or four feet, of global average sea level rise by the year 2100, requiring site managers to intervene by using adaptation techniques to improve resilience and guard against the loss of cultural heritage monuments. Understanding the history and importance of these sites to the surrounding communities and their numerous stakeholders is the first step to ensuring these sites remain …
Theoretical Framework Of Exchange Coupled Tripartite Spin Systems With Magnetic Anisotropy And Predictions Of Spin And Electronic Transport Properties For Their Use In Quantum Architectures, Eric Switzer
Electronic Theses and Dissertations, 2020-
There has been significant interest in spin systems involving two or more coupled spins as a single logical qubit, particularly for scalable quantum computing architectures. Recent realizations include the so-called singlet-triplet qubits and coupled magnetic molecules. An important class of coupled-spin systems, the three-spin paradigm for spin greater than 1/2, has not yet been fully realized in scalable qubit architectures. In this thesis, I develop the theoretical framework to investigate a class of tripartite spin models for realistic systems. First, I model a spin 1/2 particle (e.g., an electron) and two spin 1 particles (in a dimer arrangement) coupled with …
Deep Video Understanding With Model Efficiency And Sparse Active Labeling, Aayush Jung Bahadur Rana
Deep Video Understanding With Model Efficiency And Sparse Active Labeling, Aayush Jung Bahadur Rana
Electronic Theses and Dissertations, 2020-
Videos capture the inherently sequential nature of the real world, making automatic video understanding an essential need for automatic understanding of the real world. Due to major advancements in camera, communication, and storage hardware, videos have become a widely used data format for crucial applications such as home automation, security, analysis, robotics, and autonomous driving. Existing methods for video understanding require heavy computation and large training data for good performance, this limits how quick the videos can be processed and how much data can be labeled for training. Real-world video understanding requires analyzing dense scenes and sequential information, which increases …
Topological Data Analysis Using The Mapper Algorithm, Jessica Girard
Topological Data Analysis Using The Mapper Algorithm, Jessica Girard
Electronic Theses and Dissertations, 2020-
Topological data analysis is an expanding field that attempts to obtain qualitative information from a data set using topological ideas. There are two common methods of topological data analysis: persistent homology and the Mapper algorithm; the focus of this thesis is on the latter. In this thesis, we will be discussing the key ideas behind the Mapper algorithm, following the flow from Morse Theory to Reeb graphs to the topological version of the algorithm and finally to the statistical version. Lastly, we will present an application of Mapper to the USAIR97 data set using the RTDAmapper package.
Theoretical Analysis Of Charge Conduction And Rectification In Self-Assembled-Monolayers In Molecular Junctions, Francis Adoah
Theoretical Analysis Of Charge Conduction And Rectification In Self-Assembled-Monolayers In Molecular Junctions, Francis Adoah
Electronic Theses and Dissertations, 2020-
As electrical devices shrink to the atomic scale, it is expected that Moore's law will soon be obsolete for semiconductor devices. In 1974, Avriam and Ratner predicted that organic devices could replace semiconductor technology, leading to extensive research on molecular-based organic devices. This dissertation delves into the theoretical frameworks used to examine the transport in molecular junctions and aims to enhance our comprehension of charge transport and conduction properties. The studies presented in this thesis illustrates that a molecule's alteration by just a single atom can change it from an insulator to a conductor, and also that, by fine-tuning the …
Annotation Efficient Visual Recognition: From Semi-Supervised To Few-Shot Learning, Mamshad Nayeem Rizve
Annotation Efficient Visual Recognition: From Semi-Supervised To Few-Shot Learning, Mamshad Nayeem Rizve
Electronic Theses and Dissertations, 2020-
In recent years, supervised deep learning has achieved remarkable success in solving a wide range of visual recognition problems. Large-scale labeled datasets have been crucial for this success and the progress has primarily been limited to controlled environments. In this dissertation, we present methods to improve the annotation efficiency of deep visual recognition models and also propose methods to improve the performance of annotation-efficient models in unconstrained open-world settings. To address the annotation bottleneck in supervised learning, we introduce a pseudo-labeling framework for semi-supervised learning. While consistency regularization methods dominate the field, they heavily rely on domain-specific data augmentations, limiting …
Towards Efficient And Effective Representation Learning For Image And Video Understanding, Taojiannan Yang
Towards Efficient And Effective Representation Learning For Image And Video Understanding, Taojiannan Yang
Electronic Theses and Dissertations, 2020-
Deep learning has achieved tremendous success on various computer vision tasks. However, deep learning methods and models are usually computationally expensive, making it hard to train and deploy, especially on resource-constrained devices. In this dissertation, we explore how to improve the efficiency and effectiveness of deep learning methods from various perspectives. We first propose a new learning method to learn computationally adaptive representations. Traditional neural networks are static. However, our method trains adaptive neural networks that can adjust their computational cost during runtime, avoiding the need to train and deploy multiple networks for dynamic resource budgets. Next, we extend our …
Due Tomorrow, Do Tomorrow: Measuring And Reducing Procrastination Behavior Among Introductory Physics Students In An Online Environment, Zachary Felker
Due Tomorrow, Do Tomorrow: Measuring And Reducing Procrastination Behavior Among Introductory Physics Students In An Online Environment, Zachary Felker
Electronic Theses and Dissertations, 2020-
This work is focused on the measurement and prevention of procrastination behavior among college level introductory physics students completing online assignments in the form of mastery-based online learning modules. The research is conducted in two studies. The first study evaluates the effectiveness of offering students the opportunity to earn a small amount of extra credit for completing portions of their homework early. Unsupervised machine learning is used to identify an optimum cutoff duration which differentiates taking a short break during a continuous study session from a long break between two different study sessions. Using this cutoff, the study shows that …
Detecting Team Conflict From Multiparty Dialogue, Ayesha Enayet
Detecting Team Conflict From Multiparty Dialogue, Ayesha Enayet
Electronic Theses and Dissertations, 2020-
The emergence of online collaboration platforms has dramatically changed the dynamics of human teamwork, creating a veritable army of virtual teams composed of workers in different physical locations. The global world requires a tremendous amount of collaborative problem solving, primarily virtual, making it an excellent domain for computer scientists and team cognition researchers who seek to understand the dynamics involved in collaborative tasks to provide a solution that can support effective collaboration. Mining and analyzing data from collaborative dialogues can yield insights into virtual teams' thought processes and help develop virtual agents to support collaboration. Good communication is indubitably the …
A Study On Robustness And Semantic Understanding Of Visual Models, Madeline Chantry
A Study On Robustness And Semantic Understanding Of Visual Models, Madeline Chantry
Electronic Theses and Dissertations, 2020-
Vision models have improved in popularity and performance on many tasks since the emergence of large-scale datasets, improved access to computational resources, and new model architectures like the transformer. However, it is still not well understood if these models can be deployed in the real world. Because these models are "blackbox" architectures, we do not fully understand what these models are truly learning. An understanding of what models learn "underneath the hood" would result in better improvements for real-world scenarios. Motivated by this, we benchmark these impressive visual models using newly proposed datasets and tasks on their robustness and their …
Human Recognition Theory And Facial Recognition Technology: A Topic Modeling Approach To Understanding The Ethical Implication Of A Developing Algorithmic Technologies Landscape On How We View Ourselves And Are Viewed By Others, Hajer Albalawi
Electronic Theses and Dissertations, 2020-
The emergence of algorithmic-driven technology has significantly impacted human life in the current century. Algorithms, as versatile constructs, hold different meanings across various disciplines, including computer science, mathematics, social science, and human-artificial intelligence studies. This study defines algorithms from an ethical perspective as the foundation of an information society and focuses on their implications in the context of human recognition. Facial recognition technology, driven by algorithms, has gained widespread use, raising important ethical questions regarding privacy, bias, and accuracy. This dissertation aims to explore the impact of algorithms on machine perception of human individuals and how humans perceive one another …
Efficient Convolutional Neural Networks For Image Classification And Regression, Muhammad Tayyab
Efficient Convolutional Neural Networks For Image Classification And Regression, Muhammad Tayyab
Electronic Theses and Dissertations, 2020-
Neural networks have been a topic of research since 1970s and the Convolutional Neural Networks (CNNs) were first shown to work well for hand written digits recognition in 1998. These early networks were however still shallow and contained only a few layers. Moreover these networks were mostly trained on a small amount of data in contrast to the modern CNNs which contain hundreds of convolution layers and are trained on millions of images. However, this recent shift in machine learning comes at a cost. Modern neural networks have extremely large number of parameters and require huge amount of computations for …
Studying Memes During Covid Lockdown As A Lens Through Which To Understand Video-Mediated Communication Interactions, Tatyana Claytor
Studying Memes During Covid Lockdown As A Lens Through Which To Understand Video-Mediated Communication Interactions, Tatyana Claytor
Electronic Theses and Dissertations, 2020-
The purpose of this study is to analyze image macros about video-mediated communication (VMC) created during the time frame of 2020-2021 when people all over the world started using Zoom and VMC for work and school. It is a unique opportunity to study how users' interactions with themselves and with others were affected at a time when a lot of people started using the technology at the same time. Because the focus is on interactions, I narrowed it down to three topics to analyze the memes: presence, self, and space and place to analyze the memes. I chose memes relating …
Identification And Modeling Social Media Influence Pathways: A Characterization Of A Disinformation Campaign Using The Flooding-The-Zone Strategy Via Transfer Entropy, Jasser Jasser
Electronic Theses and Dissertations, 2020-
The internet has made it easy for narratives to spread quickly and widely without regard for accuracy or the harm they may cause to society. Unfortunately, this has led to the rise of bad actors who use fake and misleading articles to spread harmful misinformation. These actors flood the information space with low-quality articles in an effort to disrupt opposing narratives, sow confusion, and discourage the pursuit of truth. In societies that prioritize free speech, maintaining control over the information space remains a persistent challenge. Achieving this requires strategic planning to protect the dissemination of information in ways that promote …
Reflective Planar Optics With Cholesteric Liquid Crystal For Near-Eye Displays, Yannanqi Li
Reflective Planar Optics With Cholesteric Liquid Crystal For Near-Eye Displays, Yannanqi Li
Electronic Theses and Dissertations, 2020-
Display market has undergone dramatic changes as the near eye displays (NED) are gaining increasing attention because they offer a deeper level of human-computer interaction with the advancement of electronic devices and computer sciences. The NEDs can be presented in two ways: virtual reality (VR) and augmented reality (AR). The former is completely immersive while the latter combines the digital information with the surrounding scenes. Although several VR headsets have been commercialized for consumers and AR products for prosumers because of their high cost, but there is still a long way to go to satisfy the strict requirements of human …
Instrumental Approaches For High Resolution Photoluminescence Spectroscopy And Its Applications To Environmental Analysis, Anthony Santana
Instrumental Approaches For High Resolution Photoluminescence Spectroscopy And Its Applications To Environmental Analysis, Anthony Santana
Electronic Theses and Dissertations, 2020-
Photoluminescence phenomena provide valuable information for the direct analysis of target chemicals in complex samples. To take full advantage of the information content of fluorescence and phosphorescence phenomena, the analyst should have access to instrumentation capable to record data formats in the wavelength and time domains. Previous efforts in our lab have developed laser-based instrumentation to combine spectral and lifetime information into data formats known as wavelength time matrices (WTMs) and time-resolved excitation emission matrices (TREEMs). Recording WTMs during the emission decay of the sample makes it possible to unambiguously identify chemicals on the bases of spectral and lifetime information. …
Integrated Frequency Combs For Applications In Optical Communications & Microwave Photonics, Chinmay Shirpurkar
Integrated Frequency Combs For Applications In Optical Communications & Microwave Photonics, Chinmay Shirpurkar
Electronic Theses and Dissertations, 2020-
This dissertation reviews the advancements made in chip-scale optical frequency combs and their applications towards optical communications and optical to RF links. We review different chip-scale comb sources and in particular, chip-scale Kerr microresonator frequency combs. Then, we establish the theoretical background in nonlinear optics which allows the formation and stabilization of Kerr solitons in nonlinear cavities. We also discuss the concept of optical injection locking and in particular, multi-tone injection locking which precedes the idea of regenerative harmonic injection locking. We then go on to show the experimental work involved in soliton generation and characterization. We show efforts towards …
Clustering Of Diverse Multiplex Networks, Yaxuan Wang
Clustering Of Diverse Multiplex Networks, Yaxuan Wang
Electronic Theses and Dissertations, 2020-
This dissertation introduces the DIverse MultiPLEx Generalized Dot Product Graph (DIMPLE-GDPG) network model where all layers of the network have the same collection of nodes and follow the Generalized Dot Product Graph (GDPG) model. In addition, all layers can be partitioned into groups such that the layers in the same group are embedded in the same ambient subspace but otherwise all matrices of connection probabilities can be different. In common particular cases, where layers of the network follow the Stochastic Block Model (SBM) and Degree Corrected Block Model (DCBM), this setting implies that the groups of layers have common community …
Mapping The Focal Points Of Wordpress: A Software And Critical Code Analysis, Bryce Jackson
Mapping The Focal Points Of Wordpress: A Software And Critical Code Analysis, Bryce Jackson
Electronic Theses and Dissertations, 2020-
Programming languages or code can be examined through numerous analytical lenses. This project is a critical analysis of WordPress, a prevalent web content management system, applying four modes of inquiry. The project draws on theoretical perspectives and areas of study in media, software, platforms, code, language, and power structures. The applied research is based on Critical Code Studies, an interdisciplinary field of study that holds the potential as a theoretical lens and methodological toolkit to understand computational code beyond its function. The project begins with a critical code analysis of WordPress, examining its origins and source code and mapping selected …
Understanding, Modeling, And Simulating The Discrepancy Between Intended And Perceived Image Appearance On Optical See-Through Augmented Reality Displays, Austin Erickson
Understanding, Modeling, And Simulating The Discrepancy Between Intended And Perceived Image Appearance On Optical See-Through Augmented Reality Displays, Austin Erickson
Electronic Theses and Dissertations, 2020-
Augmented reality (AR) displays are transitioning from being primarily used in research and development settings, to being used by the general public. With this transition, these displays will be used by more people, in many different environments, and in many different contexts. Like other displays, the user's perception of virtual imagery is influenced by the characteristics of the user's environment, creating a discrepancy between the intended appearance and the perceived appearance of virtual imagery shown on the display. However, this problem is much more apparent for optical see-through AR displays, such as the HoloLens. For these displays, imagery is superimposed …
Refining The Use Of Stable Isotope Analysis In Detecting Wildlife Laundering, Kevin Guilfoyle
Refining The Use Of Stable Isotope Analysis In Detecting Wildlife Laundering, Kevin Guilfoyle
Electronic Theses and Dissertations, 2020-
The international wildlife trade has caused significant declines in wild populations. Captive breeding can reduce the pressure on wild populations caused by overcollection, but if not properly monitored, wildlife laundering can lead to further population declines. Improving the forensic ability to detect wildlife laundering will assist in monitoring the wildlife trade and enforcing regulations, thereby aiding recovery of wild populations. Stable isotope analysis has grown in importance as a forensic tool, but improvements are needed. Here, stable isotope analysis (δ13C) on eggshells of captive bred and wild sourced island apple snails (Pomacea maculata) distinguished between the two; eggshells of captive …
High-Dynamic-Range And High-Efficiency Near-Eye Display Systems, En-Lin Hsiang
High-Dynamic-Range And High-Efficiency Near-Eye Display Systems, En-Lin Hsiang
Electronic Theses and Dissertations, 2020-
Near-eye display systems, which project digital information directly into the human visual system, are expected to revolutionize the interface between digital information and physical world. However, the image quality of most near-eye displays is still far inferior to that of direct-view displays. Both light engine and imaging optics of near-eye display systems play important roles to the degraded image quality. In addition, near-eye displays also suffer from a relatively low optical efficiency, which severely limits the device operation time. Such an efficiency loss originates from both light engines and projection processes. This dissertation is devoted to addressing these two critical …
A Developmental Investigation Of Separation And Analysis Of Molecular Mass 302 Da Polyaromatic Hydrocarbons Using High Performance Liquid Chromatography And Chiral Stationary Phase, James Janesko
Electronic Theses and Dissertations, 2020-
High molecular weight – polycyclic aromatic hydrocarbons (HMW-PAH) are often found where air, water, and soil are subject to higher levels of industrial pollutants. These molecules are environmentally concerning due to their carcinogenic, mutagenic, and tumorigenic propensities. Furthermore, the isomers in this family are challenging to separate due to similar retention parameters, spectroscopic fingerprints, and mass spectral patterns. The primary purpose of this dissertation is to expand on the methodology for separation and analysis of the molecular mass 302 Da six-ring isomers using High Performance Liquid Chromatography. Retention behaviors of 21 commercially available isomers in synthetic mixture were collected via …
Impact On Infinite Asteroids: Analysis Of Ejecta Outcomes In Small Body Binary Systems, Jennifer Larson
Impact On Infinite Asteroids: Analysis Of Ejecta Outcomes In Small Body Binary Systems, Jennifer Larson
Electronic Theses and Dissertations, 2020-
Binary asteroid systems make up roughly 15% of objects occupying near-Earth space, the Main Belt, and trans-Neptunian space. The impact history of asteroids in binary systems represents an interesting aspect of the general problem pertaining to the nature and evolution of surfaces for such objects. Specifically, the post-impact dynamics of ejecta and its relation to surface modification is a challenging question owing, in part, to the unusual gravitational field in a binary system and the subsequent capture and emplacement of debris on either binary component. Observable differences or similarities between the two bodies in the color, reflectance, thermal properties, and …
Development Of Regolith Simulants Of Lunar Permanently Shadowed Regions And Jupiter Trojan Asteroids, Karlis Slumba
Development Of Regolith Simulants Of Lunar Permanently Shadowed Regions And Jupiter Trojan Asteroids, Karlis Slumba
Electronic Theses and Dissertations, 2020-
Every scientific experiment or innovation goes through a phase of testing equipment. This is not only true for experiments in the laboratory, but also very relevant for experiments on other planetary bodies. In order to test tools and robotic equipment that are destined for another planet, moon, asteroid or comet, it is necessary to simulate the regolith environment on that surface. In this thesis we have provided an overview of two methods for regolith simulant development. In one approach we made simulants in different compositions to find the best spectral fit to Jupiter Trojan asteroids. At visible to near-infrared (VNIR) …
From Human Behavior To Machine Behavior, Zerong Xi
From Human Behavior To Machine Behavior, Zerong Xi
Electronic Theses and Dissertations, 2020-
A core pursuit of artificial intelligence is the comprehension of human behavior. Imbuing intelligent agents with a good human behavior model can help them understand how to behave intelligently and interactively in complex situations. Due to the increase in data availability and computational resources, the development of machine learning algorithms for duplicating human cognitive abilities has made rapid progress. To solve difficult scenarios, learning-based methods must search for solutions in a predefined but large space. Along with implementing a smart exploration strategy, the right representation for a task can help narrow the search process during learning. This dissertation tackles three …
Improving Deep Neural Network Training With Knowledge Distillation, Dongdong Wang
Improving Deep Neural Network Training With Knowledge Distillation, Dongdong Wang
Electronic Theses and Dissertations, 2020-
Knowledge distillation, as a popular compression technique, has been widely used to reduce deep neural network (DNN) size for a variety of applications. However, in recent years, some research had found its potential for improving deep neural network performance. This dissertation focuses on further exploring its power to facilitate accurate and reliable DNN training. First, I explored data-efficient method for blackbox knowledge distillation where the specifics of the DNN for distillation is inaccessible. I integrated active learning and mixup to obtain significant distillation performance gain with limited data. This work reveals the competence of knowledge distillation to facilitate large foundation …
Towards Optimization And Robustification Of Data-Driven Models, Ehsan Kazemi Foroushani
Towards Optimization And Robustification Of Data-Driven Models, Ehsan Kazemi Foroushani
Electronic Theses and Dissertations, 2020-
In the past two decades, data-driven models have experienced a renaissance, with notable success achieved through the use of models such as deep neural networks (DNNs) in various applications. However, complete reliance on intelligent machine learning systems is still a distant dream. Nevertheless, the initial success of data-driven approaches presents a promising path for building trustworthy data-oriented models. This thesis aims to take a few steps toward improving the performance of existing data-driven frameworks in both the training and testing phases. Specifically, we focus on several key questions: 1) How to efficiently design optimization methods for learning algorithms that can …
Analysis Of Polycyclic Aromatic Hydrocarbons In Tobacco Related Samples Via High Performance Liquid Chromatography And Laser Excited Time Resolved Shpol' Skii Spectroscopy, Ahmed Comas
Electronic Theses and Dissertations, 2020-
Human exposure to polycyclic aromatic hydrocarbons (PAHs) due to cigarette smoke is well known. It is also known that PAHs are not inherent components of tobacco. Their presence in cigarette smoke results from the curing process of tobacco leaves used for the fabrication of cigarettes and the incomplete combustion of tobacco during the smoking process. The two chromatographic versions of EPA method 610 are popular approaches for the analysis of PAHs in a wide variety of samples. This method, which is based either on High-Performance Liquid-Chromatography (HPLC) or Gas-Chromatography (GC) has shown the presence of Benzo[a]pyrene (B[a]P) in tobacco samples …
Compact And High Optical Efficiency Near-Eye Displays With Liquid Crystal Flat Optics, Junyu Zou
Compact And High Optical Efficiency Near-Eye Displays With Liquid Crystal Flat Optics, Junyu Zou
Electronic Theses and Dissertations, 2020-
Since the concepts of augmented reality (AR) and virtual reality (VR) were introduced, they have attracted people's attention worldwide, both in the industry and research areas. As the most promising hardware architecture that can bring AR/VR into daily life, near eye displays (NEDs) have been studied and investigated heavily over the past half-century, especially the concept of "Metaverse" introduced by some top companies in recent years. However, the form factor and optical efficiency are two major bottlenecks for the current NEDs before they can become the major platform. Liquid crystal (LC) flat optics have several advantages, including compact, high diffraction …