Physical Sciences and Mathematics Commons^™

The Synthesis Of Memristive Neuromorphic Circuits, Austin Richard Wyer

Masters Theses

As Moores Law has come to a halt, it has become necessary to explore alternative forms of computation that are not limited in the same ways as traditional CMOS technologies and the Von Neumann architecture. Neuromorphic computing, computing inspired by the human brain with neurons and synapses, has been proposed as one of these alternatives. Memristors, non-volatile devices with adjustable resistances, have emerged as a candidate for implementing neuromorphic computing systems because of their low power and low area overhead. This work presents a C++ simulator for an implementation of a memristive neuromorphic circuit. The simulator is used within a …

The Effect Of Plant Source On Lignin-Based Polyurethanes And The Interdiffusion Dynamics Of Semi-Rigid Polymers, Jason Michael Lang

Masters Theses

The work reported in this thesis increases our understanding of the effect of lignin plant source on the mechanical and morphological properties of lignin-based polyurethanes and the interdiffusion of glassy/liquid bilayer thin films. The interdiffusion of glassy/liquid polymer pairs has received much less attention than liquid/liquid bilayers, leading to conflicting results and unresolved discrepancies. Therefore, the reported study of interdiffusion between polysulfone glassy/liquid polymer layers provides insight into the dynamics of these systems.

This thesis first reports the correlation between the mechanical properties of lignin-based polyurethanes and the lignin plant source. Lignin is a molecule that can be used as …

Development Of Large-Area Gem Detectors For The Forward Muon Endcap Upgrade Of The Cms Experiment And Search For Sm Higgs Boson Decay In The H → Τ+Τ− → Μ+Μ−¯Νμνμ¯Ντντ Channel At √ S = 13 Tev, Vallary Shashikant Bhopatkar

Theses and Dissertations

Gas Electron Multiplier (GEM) technology is being considered for the forward muon upgrade of the Compact Muon Solenoid (CMS) experiment in Phase II of the CERN LHC. The first GEM Endcap (GE1/1) is going to be installed in the 1.5 <| η |< 2.2 region of the muon endcap mainly to control muon level-1 trigger rates after the second long LHC shutdown. A GE1/1 triple-GEM detector is read out by 3,072 radial strips with 453 µrad pitch arranged in eight η-sectors. A meter-long GE1/1 prototype-III was assembled at Florida Tech and tested in 20-120 GeV hadron beams at Fermilab using Ar/CO2 70:30 and the RD51 Scalable Readout System (SRS). Four GEM detectors with 2-D readout and an average measured azimuthal resolution of 36µrad provided precise reference tracks. Construction of this GE1/1 prototype-III detector and its performance in the test beam are described. Strip cluster parameters, detection efficiency, and spatial resolution are studied with position and high voltage scans. The plateau detection efficiency is [97.80 ± 0.2 (stat)]%. The azimuthal resolution is found to be [123.5 ± 1.6 (stat)] µrad when operating in the center of the efficiency plateau and using full pulse height information. The CMS upgrade design calls for readout electronics with binary hit output. When strip clusters are formed correspondingly without charge-weighting and with fixed hit thresholds, a position resolution of [136.8 ± 2.5 stat] µrad is measured, consistent with the expected resolution from strip-pitch/√ 12 = 131.3 µrad. The eight η-sectors of the detector show a similar response and performance. VFAT3 electronics are being considered for the readout system of GE1/1 detectors. The charge that is induced on the GE1/1 readout strips by minimum-ionizing particles is an important parameter that informs the design of the amplifier-shaper input stage of the VFAT3 chip. To estimate the input charge range for these electronics, the most probable value, mean value, and 99th percentile value of the Landau distribution of the charge induced on a single strip are measured and found to be 4 fC, 11 fC, and 115 fC, respectively. The Z/γ∗ → τ τ cross section in proton-proton collisions at √ s = 13 TeV is measured, using data recorded by the CMS experiment at the LHC during 2015 and corresponding to an integrated luminosity of 2.3 fb−1 . The product of the cross section and branching fraction is measured in the dimuon final state to be 1967 ± 121 (stat.) ± 92 (syst.) ± 37 (lumi.) pb, in agreement with the standard model expectation, computed at next-to-next-to-leading order accuracy in perturbative quantum chromodynamics. A search for Standard Model (SM) Higgs bosons decaying into pairs of tau leptons and then to two muons plus (anti)-neutrinos is performed using the data collected by the CMS detector in 2016 with 35.9 fb−1 of integrated luminosity. The upper limits on the cross section relative to SM prediction are calculated in three event categories with different jet multiplicities focusing on Higgs boson signal events produced via gluon-gluon fusion and vector boson fusion. A multivariate analysis with Boosted Decision Trees (BDT) is used to suppress the large Drell-Yan background. The di-tau mass is reconstructed using a Secondary-Vertex fit (SVFit) algorithm using a maximum likelihood approach. Experimental limits are presented in all three categories extracted from the maximum likelihood fit of reconstructed di-tau mass and the visible mass of the dimuon system. The signal strength for the combination of all three categories is estimated as -1.0 ± 1.7. The expected and observed upper limits with 95% CL is at 3.2 and 2.7, respectively, with respect to the SM cross section times branching fraction.

Testing The Wind-Shock Paradigm For B-Type Star X-Ray Production With Θ Carinae, Trisha F. Doyle

Theses and Dissertations

We present Chandra X-ray grating spectroscopy of the B0.2V star, θ Carinae. θ Car is in a critical transition region between the latest O-type and earliest B-type stars, where some of these stars are observed to have UV-determined mass-loss rates much lower than theoretically expected. In general, X-ray emission in this low-luminosity regime should be less prominent than in O-star winds, but observations have shown a higher than expected production of X-ray emission from the winds of these stars (e.g., Cohen et al. 2008; Huenemoerder et al. 2012). A hot wind could explain weak UV wind signatures, but this severely …

Interaction Between Fragments Of Tau Protein Investigated By Force Spectroscopy Using Afm, Anad Mohamed Afhaima

Theses and Dissertations

Over the last couple of decades, there has been rapidly growing interest in research of natively unfolded proteins. Some proteins from this group are implicated in a number of neurodegenerative diseases. One group of neurodegenerative diseases, taupathies, is associated with tau protein. A number of biophysical and spectroscopic studies have revealed that tau protein can expand to a largely extended state and to transition rapidly between many different conformations. Although many of the techniques that elucidate structure of macromolecules have provided important information about the folded states of proteins, important information about the transition between the extended conformation states remain …

Metastable-State Nh Photoacids And Organic Photo Carbon Monoxide Releasing Materials, Aluthwatte Rallage Nawodi Madhusanka Abeyrathna

Theses and Dissertations

The recently discovered metastable-state photoacids (mPAHs) can produce a large proton concentration with high efficiency and good reversibility upon irradiation with visible light with moderate intensity. Therefore, mPAHs can be conveniently incorporated in to different systems to control various proton-transfer processes. Recently, several applications of mPAHs have been demonstrated. However, none of the previously reported mPAHs can function at a pH 7.4. Thus, biological applications of mPAHs are limited. In this work, mPAHs that can reversibly release a proton in PBS buffer (pH = 7.4) under visible light are designed and synthesized. NH-PAH-1 is the first of this type of …

A Mixed-Reality Approach For Cyber-Situation Awareness, Tapas Dipakkumar Joshi

Theses and Dissertations

As the proliferation and adoption of smart devices increase, there is an unprecedented amount of data being released into the network every second. Computer networks are the carriers for the movement of this ever generating amounts of data, but are dumb in a way that they do not distinguish between suspicious data traffic and valid data traffic. Also, for however secure a computer network be, suspicious network traffic activities are bound to happen. These suspicious traffic activities have to be detected, analyzed and stopped before it compromises the entire network and leaves the information and data security of an organization …

A Context-Free Method Of Visualizing Streaming Object Data For The Purpose Of Identifying Known Events: An Implementation And Analysis, Quinn Gregory Carver

Theses and Dissertations

This year, every second, five gigabytes of new data will be streamed to storage and yet less than half a percent of all this data will ever be analyzed. Much of this muted data is high-variety object data, unnoticed in a void of sorely needed tools to make it readily understandable. A software tool for visualizing streaming object data in a context-free manner can be built, and this tool would aid in finding predictor data for known events which are functions of the data. The design of the tool to support the hypothesis is presented and field results from over …

Mining Location And User Information From Users’ Trajectories, Marcello Tomasini

Theses and Dissertations

The understanding of human mobility is integral to the advancement of many fields including public health, city planning, economic forecasting, and it attracts the interest of researchers from a broad number of fields. The work of such researchers would not have been possible without the availability of large localized datasets such as mobile phone Call Detail Records (CDRs) provided by telco operators and Location Based Social Networks (LBSNs) check-ins provided by popular applications such as Twitter, Facebook and Foursquare. However, such datasets are often incomplete, anonymized, and/or inaccurate. Hence there is a need to partially reconstruct or extract more information …

Decision Support For Shared Responsibility Of Cloud Security Metrics, Moteeb Aieed Al Moteri

Theses and Dissertations

With the rapid growth of cloud computing and the increasing importance of measuring the security of cloud systems, more attention has been focused on the need for security metrics that are specific to cloud computing. The use of metrics in cloud computing enables improved service selection, service agreement, and service verification. This dissertation presents a taxonomy of cloud security metrics and guideline and a framework for allocating cloud security metrics shared responsibility. The taxonomy considers several novel viewpoints. Metrics are organized by cloud capability type (Application, Platform, Infrastructure) along with the type of cloud deployment (public, private, hybrid, community), and …

Parametric And Non-Parametric Regression Models With Applications To Climate Change, Osita Eluemuno Onyejekwe

Theses and Dissertations

In this dissertation we have studied the climate factors that contribute to climate change using univariate and multivariate parametric methods as well as nonparametric models. In this study, we have three major contributions. First, the extent of mountain glaciers around the globe and their responses to climate factors are investigated using multivariate methods and we have proposed a predictive model to estimate the mountain glacier response to climate factors. Second, we have addressed the important problem of bandwidth selection in presence of correlated noise in nonparametric regression analysis. We have proposed a denoising method based on an ensemble bandwidth optimization …

On Logconcavity Of Multivariate Discrete Distributions, Majed Ghazi Alharbi

Theses and Dissertations

The contribution of this dissertation to the literature is twofold. First, we use a geometric perspective to present all possible subdivisions of R³ into tetrahedra with disjoint interiors and adopt a combinatorial approach to obtain a special subdivision of Rⁿ into simplices with disjoint interiors, where two simplices are called neighbors if they share a common facet. We then use the neighborhood relationship of the simplices in each subdivision to fully describe the sufficient conditions for the strong unimodality/logconcavity of the trivariate discrete distributions and further extend these results to present a new sufcient condition for the strong unimodality/logconcavity of …

Copper Tolerance Of Amphibalanus Amphitrite As Observed In Central Florida, Hannah Grace Brinson

Theses and Dissertations

Copper tolerance in the invasive barnacle Amphibalanus amphitrite has been observed in Florida by the Center for Corrosion and Biofouling Control since 2012 and by Weiss (1947). To test the theory that this barnacle preferentially settles on copper coated surfaces to avoid settlement competition by other sessile species, a series of two experiments and a literature review of historical copper toxicity tests on larval barnacles was conducted. The barnacle A amphitrite was preferentially used in many previous toxicity studies because it is readily available, has high fecundity, and is more sensitive to some toxicants than other species, including the native …

St. Lucie Shoal Complex: Regional Sediment Resource Or Submerged Storm Breakwater, Leaf Erickson

Theses and Dissertations

Nearshore sand shoals have become the predominant sediment resource for beach nourishment projects on the east coast of Florida. Along this coast, the St. Lucie Shoal Complex (SLSC) is comprised of several shoals designated as sediment resources for beach nourishment, many having depths less than 7 meters, at their crests. This group of shoals represents the largest high-quality beach nourishment sediment resource in southeast Florida. Among these shoals, the St. Lucie shoal is the largest and shallowest at the crest. This project explores the current best practice methodologies to explore impacts of excavating sand resources from shallow-crested shoal systems like …

The Morphology And Uniformity Of Circumstellar Oh/H2O Masers Around Oh/Ir Stars, Derek Sean Felli

Theses and Dissertations

Even though low mass stars (< 8 solar masses) vastly outnumber high mass stars (< 8 solar masses), the more massive stars drive the chemical evolution of galaxies from which the next generation of stars and planets can form. Understanding mass loss of asymptotic giant branch stars contributes to our understanding of the chemical evolution of the galaxy, stellar populations, and star formation history. Stars with mass < 8 solar masses form planetary nebulae, while those with mass < 8 solar masses go supernova. In both cases, these stars enrich their environments with elements heavier than simple hydrogen and helium molecules. While some general info about how stars die and form planetary nebulae are known, specific details are missing due to a lack of high-resolution observations and analysis of the intermediate stages. For example, we know that mass loss in stars creates morphologically diverse planetary nebulae, but we do not know the uniformity of these processes, and therefore lack detailed models to better predict how spherically symmetric stars form asymmetric nebulae. We have selected a specific group of late-stage stars and observed them at different scales to reveal the uniformity of mass loss through different layers close to the star. This includes observing nearby masers that trace the molecular shell structure around these stars. This study revealed detailed structure that was analyzed for uniformity to place constraints on how the mass loss processes behave in models. These results will feed into our ability to create more detailed models to better predict the chemical evolution of the next generation of stars and planets.

Quantitative Morphological Classification Of Planetary Craterforms Using Multivariate Methods Of Outline-Based Shape Analysis, Thomas Joseph Slezak

Theses and Dissertations

Craters formed by impact and volcanic processes are among the most fundamental planetary landforms. This study examines the morphology of diverse craterforms on Io, the Moon, Mars, and Earth using quantitative, outline-based shape analysis and multivariate statistical methods to evaluate the differences between different types of. Ultimately, this should help establish relationships between the form and origin of craterforms. Developed in the field of geometric morphometrics by paleontological and biological sciences communities, these methods were used for the analysis of the shapes of crater outlines. The shapes of terrestrial ash-flow calderas, terrestrial basaltic shield calderas, martian calderas, Ionian paterae, and …

Digitizing Dinosaur National Monument's Carnegie Quarry, Rebecca Esplin

Theses and Dissertations

The Carnegie Quarry in northeastern Utah is world-renowned for the dinosaur skeletons it has produced and for its in situ display of dinosaur bones. The specimens excavated at Carnegie Quarry are displayed and curated in 20 repositories, most in North America. Data on these specimens in the forms of notes, photographs, publications, field maps, and so on, are scattered in an array of formats and institutions. The primary goal of this thesis is to develop a database linking these data with a digital map (GIS system) to make them readily accessible. To this end, a relational database was created using …

Machine Learning To Discover And Optimize Materials, Conrad Waldhar Rosenbrock

Theses and Dissertations

For centuries, scientists have dreamed of creating materials by design. Rather than discovery by accident, bespoke materials could be tailored to fulfill specific technological needs. Quantum theory and computational methods are essentially equal to the task, and computational power is the new bottleneck. Machine learning has the potential to solve that problem by approximating material behavior at multiple length scales. A full end-to-end solution must allow us to approximate the quantum mechanics, microstructure and engineering tasks well enough to be predictive in the real world. In this dissertation, I present algorithms and methodology to address some of these problems at …

A Coverage Metric To Aid In Testing Multi-Agent Systems, Jane Ostergar Linn

Theses and Dissertations

Models are frequently used to represent complex systems in order to test the systems before they are deployed. Some of the most complicated models are those that represent multi-agent systems (MAS), where there are multiple decision makers. Brahms is an agent-oriented language that models MAS. Three major qualities affect the behavior of these MAS models: workframes that change the state of the system, communication activities that coordinate information between agents, and the schedule of workframes. The primary method to test these models that exists is repeated simulation. Simulation is useful insofar as interesting test cases are used that enable the …

Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack

Theses and Dissertations

Using a finite element method, we numerically solve the time-dependent Ginzburg-Landau equations of superconductivity to explore vortex nucleation in type II superconductors. We consider a cylindrical geometry and simulate the transition from a superconducting state to a mixed state. Using saddle-node bifurcation theory we evaluate the superheating field for a cylinder. We explore how surface roughness and thermal fluctuations influence vortex nucleation. This allows us to simulate material inhomogeneities that may lead to instabilities in superconducting resonant frequency cavities used in particle accelerators.

Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack

Theses and Dissertations

Using a finite element method, we numerically solve the time-dependent Ginzburg-Landau equations of superconductivity to explore vortex nucleation in type II superconductors. We consider a cylindrical geometry and simulate the transition from a superconducting state to a mixed state. Using saddle-node bifurcation theory we evaluate the superheating field for a cylinder. We explore how surface roughness and thermal fluctuations influence vortex nucleation. This allows us to simulate material inhomogeneities that may lead to instabilities in superconducting resonant frequency cavities used in particle accelerators.

Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton

Theses and Dissertations

An important obstacle to a functional cure for HIV/AIDS is the persistence of viral reservoirs found throughout the body in various cells and tissues. Reservoirs can be latently infected cells, or in the case of follicular dendritic cells (FDC), non-infected cells that trap infectious virus on their surface through immune complexes (HIV-IC). Although several strategies have been employed to target and eliminate viral reservoirs, they are short-lived and ineffective. In an attempt to provide a long-term approach, chimeric antigen receptor T (CAR-T) cells were designed to eliminate native HIV on FDCs. Although effective at eliminating HIV-infected cells, and halting spreading …

An Lntegrated Approach (Remote Sensing, Hydrogeology, Geotechnical, And Geoinformatics) To Assess And Monitor Fossil Aquifers And Associated Land Deformation Over The Arabian Peninsula, Abdullah Ghurmullah Saeed Othman

Dissertations

Deformational features such as subsidence, sinkholes, fissures, settling and cracks in buildings and structures, and earthquakes are being reported from many of the world’s arid lands, in areas where fossil aquifers are being excessively exploited. Using the Lower Mega Aquifer System (LMAS) in Arabia as a test site, I applied an integrated approach (remote sensing, geodesy, GIS, geology, hydrogeology, and geotechnical) to identify nature, intensity, spatial distribution, and factors controlling the observed deformation in the central (Al-Qassim and Ha'il regions; area: 16×10⁴ km²) and the northern (Wadi As-Sirhan Basin; area: ~10.9×10⁴ km²) Arabia. A four -fold approach was adopted to …

A Hybrid Parallel Approach To High-Performance Compression Of Big Genomic Files And In Compresso Data Processing, Sandino N. Vargas Pérez

Dissertations

Due to the rapid development of high-throughput low cost Next-Generation Sequencing, genomic file transmission and storage is now one of the many Big Data challenges in computer science. Highly specialized compression techniques have been devised to tackle this issue, but sequential data compression has become increasingly inefficient and existing parallel algorithms suffer from poor scalability. Even the best available solutions can take hours to compress gigabytes of data, making the use of these techniques for large-scale genomics prohibitively expensive in terms of time and space complexity.

This dissertation responds to the aforementioned problem by presenting a novel hybrid parallel approach …

Ldentifying And Characterizing Cognitive Factors Significant To Practicing And Learning Meteorology, Peggy M. Mcneal

Dissertations

To see the world as a meteorologist, one must understand and interpret atmospheric processes through representations depicted on two-dimensional weather charts and maps that encode large amounts of spatial and numerical data. This is a cognitively demanding and spatially challenging task, especially for students with burgeoning levels of meteorology knowledge, who lack the expertise of practiced meteorologists that read such charts and maps with ease. With little prior work informing meteorology and meteorology education through a cognitive science lens, this study surveys the literature and follows models of discipline-based education and cognitive science research to identify the discrete intelligence factors …

Vkse-Mo: Verifiable Keyword Search Over Encrypted Data In Multi-Owner Settings, Yinbin Miao, Jianfeng Ma, Ximeng Liu, Junwei Zhang, Zhiquan Liu

Research Collection School Of Computing and Information Systems

Searchable encryption (SE) techniques allow cloud clients to easily store data and search encrypted data in a privacy-preserving manner, where most of SE schemes treat the cloud server as honest-but-curious. However, in practice, the cloud server is a semi-honest-but-curious third-party, which only executes a fraction of search operations and returns a fraction of false search results to save its computational and bandwidth resources. Thus, it is important to provide a results verification method to guarantee the correctness of the search results. Existing SE schemes allow multiple data owners to upload different records to the cloud server, but these schemes have …

D-Watch: Embracing “Bad” Multipaths For Device-Free Localization With Cots Rfid Devices, Ju Wang, Jie Xiong, Hongbo Jiang, Xiaojiang Chen, Dingyi Fang

Research Collection School Of Computing and Information Systems

Device-free localization, which does not require any device attached to the target, is playing a critical role in many applications, such as intrusion detection, elderly monitoring and so on. This paper introduces D-Watch, a device-free system built on the top of low cost commodity-off-the-shelf RFID hardware. Unlike previous works which consider multipaths detrimental, D-Watch leverages the ''bad'' multipaths to provide a decimeter-level localization accuracy without offline training. D-Watch harnesses the angle-of-arrival information from the RFID tags' backscatter signals. The key intuition is that whenever a target blocks a signal's propagation path, the signal power experiences a drop which can be …

Leveraging The Trade-Off Between Accuracy And Interpretability In A Hybrid Intelligent System, Di Wang, Chai Quek, Ah-Hwee Tan, Chunyan Miao, Geok See Ng, You Zhou

Research Collection School Of Computing and Information Systems

Neural Fuzzy Inference System (NFIS) is a widely adopted paradigm to develop a data-driven learning system. This hybrid system has been widely adopted due to its accurate reasoning procedure and comprehensible inference rules. Although most NFISs primarily focus on accuracy, we have observed an ever increasing demand on improving the interpretability of NFISs and other types of machine learning systems. In this paper, we illustrate how we leverage the trade-off between accuracy and interpretability in an NFIS called Genetic Algorithm and Rough Set Incorporated Neural Fuzzy Inference System (GARSINFIS). In a nutshell, GARSINFIS self-organizes its network structure with a small …

Base Faith, Stefano Harney, Fred Moten

Research Collection Lee Kong Chian School Of Business

The earth moves against the world. And today the response of the world is clear. The world answers in fire and flood. The more the earth churns the more vicious the world’s response. But the earth still moves. Tonika Sealy Thompson might call it a procession. The earth’s procession is not on the world’s calendar. It is not a parade on a parade ground. It is not in the world’s teleology. Nor is the procession exactly a carnival played to mock or overturn this parade, to take over its grounds. A procession moves unmoved by the world. The earth’s procession …

Who Are Your Users? Comparing Media Professionals' Preconception Of Users To Data-Driven Personas, Lene Nielsen, Soon-Gyu Jung, Jisun An, Joni Salminen, Haewoon Kwak, Bernard J. Jansen

Research Collection School Of Computing and Information Systems

One of the reasons for using personas is to align user understandings across project teams and sites. As part of a larger persona study, at Al Jazeera English (AJE), we conducted 16 qualitative interviews with media producers, the end users of persona descriptions. We asked the participants about their understanding of a typical AJE media consumer, and the variety of answers shows that the understandings are not aligned and are built on a mix of own experiences, own self, assumptions, and data given by the company. The answers are sometimes aligned with the data-driven personas and sometimes not. The end …