Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 61 - 82 of 82

Full-Text Articles in Entire DC Network

I’M Being Framed: Phase Retrieval And Frame Dilation In Finite-Dimensional Real Hilbert Spaces, Jason L. Greuling Jan 2018

I’M Being Framed: Phase Retrieval And Frame Dilation In Finite-Dimensional Real Hilbert Spaces, Jason L. Greuling

Honors Undergraduate Theses

Research has shown that a frame for an n-dimensional real Hilbert space offers phase retrieval if and only if it has the complement property. There is a geometric characterization of general frames, the Han-Larson-Naimark Dilation Theorem, which gives us the necessary and sufficient conditions required to dilate a frame for an n-dimensional Hilbert space to a frame for a Hilbert space of higher dimension k. However, a frame having the complement property in an n-dimensional real Hilbert space does not ensure that its dilation will offer phase retrieval. In this thesis, we will explore and provide what necessary and sufficient …


Climate Modeling, Outgoing Longwave Radiation, And Tropical Cyclone Forecasting, Thomas Rechtman Jan 2018

Climate Modeling, Outgoing Longwave Radiation, And Tropical Cyclone Forecasting, Thomas Rechtman

Honors Undergraduate Theses

Climate modeling and tropical cyclone forecasting are two significant is- sues that are continuously being improved upon for more accurate weather forecasting and preparedness. In this thesis, we have studied three climate models and formulated a new model with a view to determine the outgoing longwave radiation (OLR) budget at the top of the atmosphere (TOA) as ob- served by the National Oceanic and Atmospheric Administration’s (NOAA) satellite based Advanced Very High Resolution Radiometer (AVHRR). In 2006, Karnauskas proposed the African meridional OLR as an Atlantic hur- ricane predictor, the relation was further proven in 2016 by Karnauskas and Li …


Mathematical Models Of Mosquito Populations, Hanna Reed Jan 2018

Mathematical Models Of Mosquito Populations, Hanna Reed

Honors Undergraduate Theses

The intent of this thesis is to develop ordinary differential equation models to better understand the mosquito population. We first develop a framework model, where we determine the condition under which a natural mosquito population can persist in the environment. Wolbachia is a bacterium which limits the replication of viruses inside the mosquito which it infects. As a result, infecting a mosquito population with Wolbachia can decrease the transmission of viral mosquito-borne diseases, such as dengue. We develop another ODE model to investigate the invasion of Wolbachia in a mosquito population. In a biologically feasible situation, we determine three coexisting …


Psychometric Properties Of A Working Memory Span Task, Juan M. Alzate Vanegas Jan 2018

Psychometric Properties Of A Working Memory Span Task, Juan M. Alzate Vanegas

Honors Undergraduate Theses

The intent of this thesis is to examine the psychometric properties of a complex span task (CST) developed to measure working memory capacity (WMC) using measurements obtained from a sample of 68 undergraduate students at the University of Central Florida. The Grocery List Task (GLT) promises several design improvements over traditional CSTs in a prior study about individual differences in WMC and distraction effects on driving performance, and it offers potential benefits for studying WMC as well as the serial-position effect. Currently, the working memory system is composed of domain-general memorial storage processes and information-processing, which involves the use of …


Surfactant Driven Assembly Of Freeze-Casted, Polymer-Derived Ceramic Nanoparticles On Grapehene Oxide Sheets For Lithium-Ion Battery Anodes, Ali Zein Khater Jan 2018

Surfactant Driven Assembly Of Freeze-Casted, Polymer-Derived Ceramic Nanoparticles On Grapehene Oxide Sheets For Lithium-Ion Battery Anodes, Ali Zein Khater

Honors Undergraduate Theses

Traditional Lithium-Ion Batteries (LIBs) are a reliable and cost-efficient choice for energy storage. LIBs offer high energy density and low self-discharge. Recent developments in electric-based technologies push for replacing historically used Lead-Acid batteries with LIBs. However, LIBs do not yet meet the demands of modern technology. Silicon and graphene oxide (GO) have been identified as promising replacements to improve anode materials. Graphene oxide has a unique sheet-like structure that provides a mechanically stable, light weight material for LIB anodes. Due to its structure, reduced graphene oxide (rGO) is efficiently conductive and resistive to environmental changes. On the other hand, silicon-based …


Resonant Anisotropic Emission In Rabbitt Spectroscopy, Bejan M. Ghomashi Jan 2018

Resonant Anisotropic Emission In Rabbitt Spectroscopy, Bejan M. Ghomashi

Honors Undergraduate Theses

A variant of RABBITT pump-probe spectroscopy in which the attosecond pulse train comprises both even and odd harmonics of the fundamental IR probe frequency is explored to measure time-resolved photoelectron emission in systems that exhibit autoionizing states. It is shown that the group delay of both one-photon and two-photon resonant transitions is directly encoded in the energy-resolved photoelectron anisotropy as a function of the pump-probe time-delay. This principle is illustrated for a 1D model with symmetric zero-range potentials that supports both bound states and shape-resonances. The model is studied using both perturbation theory and solving the time-dependent Schodinger equation on …


Nanoscale Characterization And Mechanism Of Electroless Deposition Of Silver Metal, Christopher Grabill Jan 2018

Nanoscale Characterization And Mechanism Of Electroless Deposition Of Silver Metal, Christopher Grabill

Electronic Theses and Dissertations

This dissertation is an investigation of the nanoscale characteristics and mechanism of electrolessly deposited silver metal seeded by gold nanoparticles. The process of growing seed-nanoparticles on a polymer surface was studied. Several bifunctional amines and organic reducing agents were used to explore how these chemical factors affect the size and distribution of gold nanoparticles formed at the interface. The nanoparticles were characterized by transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). An electroless deposition (ED) bath developed by Danscher was selected to study electroless deposition of silver in detail. The chemical species in the bath …


Advancing Practical Specification Techniques For Modern Software Systems, John Singleton Jan 2018

Advancing Practical Specification Techniques For Modern Software Systems, John Singleton

Electronic Theses and Dissertations

The pervasive nature of software (and the tendency for it to contain errors) has long been a concern of theoretical computer scientists. Many investigators have endeavored to produce theories, tools, and techniques for verifying the behavior of software systems. One of the most promising lines of research is that of formal specification, which is a subset of the larger field of formal methods. In formal specification, one composes a precise mathematical description of a software system and uses tools and techniques to ensure that the software that has been written conforms to this specification. Examples of such systems are Z …


Thin-Film Lithium Niobate Photonics For Electro-Optics, Nonlinear Optics, And Quantum Optics On Silicon, Ashutosh Rao Jan 2018

Thin-Film Lithium Niobate Photonics For Electro-Optics, Nonlinear Optics, And Quantum Optics On Silicon, Ashutosh Rao

Electronic Theses and Dissertations

Ion-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated photonics based on lithium niobate. These thin-film LN waveguides offer over an order of magnitude improvement in optical confinement, and about two orders of magnitude reduction in waveguide bending radius, compared to conventional LN waveguides. Harnessing the improved confinement, a variety of miniaturized and efficient photonic devices are demonstrated in this work. First, two types of compact electrooptic modulators are presented – microring modulators, and Mach-Zehnder modulators. Next, two distinct approaches to nonlinear optical frequency converters are implemented – periodically poled lithium niobate, and mode shape …


Determining The Small-Scale Structure And Particle Properties In Saturn's Rings From Stellar And Radio Occultations, Richard Jerousek Jan 2018

Determining The Small-Scale Structure And Particle Properties In Saturn's Rings From Stellar And Radio Occultations, Richard Jerousek

Electronic Theses and Dissertations

Saturn's rings consist of icy particles of various sizes ranging from millimeters to several meters. Particles may aggregate into ephemeral elongated clumps known as self-gravity wakes in regions where the surface mass density and epicyclic frequency give a Toomre critical wavelength which is much larger than the largest individual particles (Julian and Toomre 1966). Optical depth measurements at different wavelengths can be used to constrain the sizes of individual particles (Zebker et al. 1985, Marouf et al. 1983) while measurements of optical depths spanning many viewing geometries can be used to determine the properties of self-gravity wakes (Colwell et al. …


Development And Characterization Of Solid-Contact Paper-Based And Micro Ion-Selective Electrodes For Environmental Analysis, Stephanie Armas Jan 2018

Development And Characterization Of Solid-Contact Paper-Based And Micro Ion-Selective Electrodes For Environmental Analysis, Stephanie Armas

Electronic Theses and Dissertations

Ion-selective electrodes (ISEs) have extensively been used for food analysis, as medical diagnostic tools, and for some environmental applications. However, ISEs are hindered by the need of a bulky reference electrode and the pre-conditioning step of the sensor, which can often be lengthy. This work will discuss how the direct addition of target analyte into the cocktail sensing membrane can circumvent the pre-conditioning step. Furthermore, the work is presented in an optimized ready-to-use single strip design, where the bulky glass reference electrode (RE) is no longer needed. The bulky RE was replaced by drop casting a simple two-component mixture consisting …


Quantitative Line Assignment In Optical Emission Spectroscopy, Jessica Chappell Jan 2018

Quantitative Line Assignment In Optical Emission Spectroscopy, Jessica Chappell

Electronic Theses and Dissertations

Quantitative elemental analysis using Optical Emission Spectroscopy (OES) starts with a high level of confidence in spectral line assignment from reference databases. Spectral interferences caused by instrumental and line broadening decrease the resolution of OES spectra creating uncertainty in the elemental profile of a sample for the first time. An approach has been developed to quantify spectral interferences for individual line assignment in OES. The algorithm calculates a statistical interference factor (SIF) that combines a physical understanding of plasma emission with a Bayesian analysis of the OES spectrum. It can be used on a single optical spectrum and still address …


Towards High-Performance Big Data Processing Systems, Hong Zhang Jan 2018

Towards High-Performance Big Data Processing Systems, Hong Zhang

Electronic Theses and Dissertations

The amount of generated and stored data has been growing rapidly, It is estimated that 2.5 quintillion bytes of data are generated every day, and 90% of the data in the world today has been created in the last two years. How to solve these big data issues has become a hot topic in both industry and academia. Due to the complex of big data platform, we stratify it into four layers: storage layer, resource management layer, computing layer, and methodology layer. This dissertation proposes brand-new approaches to address the performance of big data platforms like Hadoop and Spark on …


A Value Sensitive Design Approach To Adolescent Mobile Online Safety, Arup Kumar Ghosh Jan 2018

A Value Sensitive Design Approach To Adolescent Mobile Online Safety, Arup Kumar Ghosh

Electronic Theses and Dissertations

With the rise of adolescent smartphone use, concerns about teen online safety are also on the rise. A number of parental control apps are available for mobile devices, but adoption of these apps has been markedly low. To better understand these apps, their users, and design opportunities in the space of mobile online safety for adolescents, we have conducted four studies informed by the principles of Value Sensitive Design (VSD). In Study 1 (Chapter 2), we conducted a web-based survey of 215 parents and their teens (ages 13-17) using two separate logistic regression models (parent and teen) to examine the …


Evolution And Distribution Of Phenotypic Diversity In The Venom Of Mojave Rattlesnakes (Crotalus Scutulatus), Jason Strickland Jan 2018

Evolution And Distribution Of Phenotypic Diversity In The Venom Of Mojave Rattlesnakes (Crotalus Scutulatus), Jason Strickland

Electronic Theses and Dissertations

Intraspecific phenotype diversity allows for local adaption and the ability for species to respond to changing environmental conditions, enhancing survivability. Phenotypic variation could be stochastic, genetically based, and/or the result of different environmental conditions. Mojave Rattlesnakes, Crotalus scutulatus, are known to have high intraspecific venom variation, but the geographic extent of the variation and factors influencing venom evolution are poorly understood. Three primary venom types have been described in this species based on the presence (Type A) or absence (Type B) of a neurotoxic phospholipase A2 called Mojave toxin and an inverse relationship with the presence of snake venom metalloproteinases …


Qualitative And Quantitative Elemental Composition Analysis Of The Surrounding Pollen Coating Via Icp-Ms, Brandy Voyer Jan 2018

Qualitative And Quantitative Elemental Composition Analysis Of The Surrounding Pollen Coating Via Icp-Ms, Brandy Voyer

Electronic Theses and Dissertations

Pollen evidence has proven to be a powerful forensic tool to trace a suspect or item to a victim or a crime scene. This is possible because it is microscopic, abundant in nature, resistant to degradation and decay; it presents dispersal patterns that can be used to generate a 'fingerprint' within specific areas, and has illustrated a unique morphology that can be used to classify species. While the pollen grain morphology has been extensively used to characterize the specific species, not much has been investigated as pertains to the coating that surrounds the pollen grain aside from it being categorized …


In Quest Of Bernstein Inequalities Rational Functions, Askey-Wilson Operator, And Summation Identities For Entire Functions, Rajitha Puwakgolle Gedara Jan 2018

In Quest Of Bernstein Inequalities Rational Functions, Askey-Wilson Operator, And Summation Identities For Entire Functions, Rajitha Puwakgolle Gedara

Electronic Theses and Dissertations

The title of the dissertation gives an indication of the material involved with the connecting thread throughout being the classical Bernstein inequality (and its variants), which provides an estimate to the size of the derivative of a given polynomial on a prescribed set in the complex plane, relative to the size of the polynomial itself on the same set. Chapters 1 and 2 lay the foundation for the dissertation. In Chapter 1, we introduce the notations and terminology that will be used throughout. Also a brief historical recount is given on the origin of the Bernstein inequality, which dated back …


Mode-Locked Laser Based On Large Core Yb3+-Doped Fiber, Fei Jia Jan 2018

Mode-Locked Laser Based On Large Core Yb3+-Doped Fiber, Fei Jia

Electronic Theses and Dissertations

The thesis reviews principle of laser cavity and gives a general introduction to modelocked laser (MLL). By using Yb3+-doped fiber as gain medium, passive MLL cavity is developed in experiment, aiming to obtain femtosecond pulses with high pump power from 25W to 35W. The gain medium fiber with 65µm core diameter is cleaved with one flat end and another angled. Pump laser with 976nm wavelength is coupled into Yb3+ -doped fiber to excite signal from 1020nm to 1040nm in the core. 9W is threshold for laser setup. After locking all modes, picosecond pulses are output from laser cavity and coupled …


Experimental Confirmation Of Ballistic Nanofriction And Quasiparticle Interference In Dirac Materials., Michael Lodge Jan 2018

Experimental Confirmation Of Ballistic Nanofriction And Quasiparticle Interference In Dirac Materials., Michael Lodge

Electronic Theses and Dissertations

This dissertation is broadly divided into two parts. The first part details the development and usage of an experimental apparatus to measure the dry nanofriction for a well-defined interface at high sliding speeds. I leverage the sensitivity of a quartz crystal microbalance (QCM) to determine the drag coefficient of an ensemble of gold nanocrystals sliding on graphene at speeds up to 11 cm/s. I discuss the theories of velocity-dependent friction, especially at high sliding speeds, and QCM modeling. I also discuss our synthesis protocols for graphene and molybdenum disulfide, as well as our protocol for fabricating a clean, graphene-laminated QCM …


Environmental Physical-Virtual Interaction To Improve Social Presence With A Virtual Human In Mixed Reality, Kangsoo Kim Jan 2018

Environmental Physical-Virtual Interaction To Improve Social Presence With A Virtual Human In Mixed Reality, Kangsoo Kim

Electronic Theses and Dissertations

Interactive Virtual Humans (VHs) are increasingly used to replace or assist real humans in various applications, e.g., military and medical training, education, or entertainment. In most VH research, the perceived social presence with a VH, which denotes the user's sense of being socially connected or co-located with the VH, is the decisive factor in evaluating the social influence of the VH—a phenomenon where human users' emotions, opinions, or behaviors are affected by the VH. The purpose of this dissertation is to develop new knowledge about how characteristics and behaviors of a VH in a Mixed Reality (MR) environment can affect …


In Situ Treatment Systems For Remediation Of Polychlorinated Biphenyl-Contaminated Building Materials, Adibah Almutairi Jan 2018

In Situ Treatment Systems For Remediation Of Polychlorinated Biphenyl-Contaminated Building Materials, Adibah Almutairi

Electronic Theses and Dissertations

Polychlorinated Biphenyls (PCBs) are a family of synthetic organohalides comprising 209 congeners which were used historically as additives in paint and caulking materials over a span of many years. Even though the production of PCBs in the USA has been banned since the late 1970s, their former prevalence and widespread use means many structures are still coated with PCB-laden paints. In addition, the presence of PCBs in elastic sealants has resulted in transport of PCBs into concrete structures and has caused soil contamination around buildings. PCB-contaminated building materials have become a significant concern for the environment and building occupants due …


Catalyst Design And Mechanism Study With Computational Method For Small Molecule Activation, Muqiong Liu Jan 2018

Catalyst Design And Mechanism Study With Computational Method For Small Molecule Activation, Muqiong Liu

Electronic Theses and Dissertations

Computational chemistry is a branch of modern chemistry that utilizes the computers to solve chemical problems. The fundamental of computational chemistry is Schrödinger equation. To solve the equation, researchers developed many methods based on BornOppenheimer Approximation, such as Hartree-Fock method and DFT method, etc. Computational chemistry is now widely used on reaction mechanism study and new chemical designing. In the first project described in Chapter 3, we designed phosphine oxide modified Ag3, Au3 and Cu3 nanocluster catalysts with DFT method. We found that these catalysts were able to catalyze the activation of H2 by cleaving the H-H bond asymmetrically. The …