Digital Commons Network^™

On The Projections Of Commutative C*-Algebras, Alaa Ahmad Hamdan

Theses

Gelfand and Naimark proved that the Banach algebra of continuous complex-valued functions on a compact space Ω is the only example of commutative unital C*-algebras. We study the C*-algebra C(Ω) and its main elements, such as projections. Also, we discuss the mapping between projections, which preserves orthogonality (orthoisomorphism). A bijective θ between projections induces a bijective Θ between the Boolean algebra of clopen subsets of X. Then, we give main properties of such Θ. For a compact subset X of ℝ, we classify the projections of C(X) by introducing the similar relation on P(C(X)). We introduce an …

Virtual Laboratories For Stem Education: An Evaluation Model And Comparison, Jumana Mahmoud Kharsa

Theses

Laboratory work is key to science education, and virtual environments play a vital role in remote learning. This thesis is concerned with the evaluation of virtual laboratories used in educational fields, mainly in STEM courses. This research investigates the basic criteria for evaluating virtual environments used in science education in order to create an evaluation scale. We reviewed the literature to highlight the main guidelines of evaluating virtual laboratories and found that the most common evaluation features for virtual tools are Ease of Use, Usefulness, Motivation, Interface Design, and Realism. Upon generating the assessment scale, we selected two web-based interactive …

Design Of Low-Cost Power Quality And Energy Monitoring System For Low Voltage Distribution Network, Rami Moustafa Mohyeldeen

Theses

The constant increase of non-linear loads and the future high integration of renewable energy sources in the power grid make power quality monitoring systems crucial to maintain maximum efficiency and reliability. However, the current devices for power quality monitoring are costly, limiting PQ monitoring systems' usage to specific applications and for a particular time. This thesis aims to present a design and the implementation of a low-cost power quality monitoring system using a single-board computer (Raspberry Pi) and highly accurate multiphase power quality monitoring ADE9000 IC. The proposed PQM system is configured to work remotely through either a wireless connection …

A Blockchain Based Policy Framework For The Management Of Electronic Health Record (Ehrs), Aysha Ali Mohammed Murad Qambar

Theses

The rapid development of information technology during the last decade has greatly influenced all aspects of society, including individuals and enterprise organizations. Adopting new technologies by individuals and organizations depends on several factors, such as usability, available resources, support needed for adoption benefits, and return on investment, to mention a few. When it comes to the adoption of new technologies, one of the main challenges faced by organizations is the ability to effectively incorporate such technologies into their enterprise solutions to maximize the expected benefits. For the last several years, Blockchain technology has become a popular trend in a variety …

Numerical Methods For Locating Zeros Of Polynomial Systems Using Resultant, Ayade Salah Abdelmalk

Theses

In this thesis, we modify two methods for locating zeros of polynomial systems which are one dimensional path following and Lanczos method. Both approaches are based on calculating the resultant matrix corresponding to each variable in the system. These methods are stable and preserving the spareness of these matrices. These methods are developed to avoid using the zeros of the multiresultant of each variable which are condition problems. Theoretical and numerical results will be given to show the efficiency of these methods. Finally, algorithms for the Mathematica codes are given.

Disturbance-Observer Based Control For Pwm Rectifiers Without Dc Voltage Oscillations Under Unbalanced Grid Conditions, Mohammed Samer Al-Razehi

Theses

A three-phase controlled rectifier is a power electronic converter that employs the grid voltages as an input to produce a constant dc voltage at its output through the use of a capacitor, known as dc-link capacitor. However, the switching devices of power converters can create harmonics in the grid current, which mandates the need for filters to ensure high-quality grid current. This explains why the power converter is normally connected to the grid using passive filters such as L filter or LCL filter. The L filter is normally preferred over LCL filter to reduce harmonic distortions in grid currents as …

The Status Of Homogeneous Grouping Implication In English Language Classrooms In The United Arab Emirates, Eman Mohamed Abdelwahab

Theses

This thesis is concerned with the status of homogeneous grouping implication in English language classrooms in the United Arab Emirates public schools. The study aims at exploring students’ and teachers’ perceptions toward homogeneous learning in English language classrooms, encountered challenges and possible suggestions of improvement. The Mixed method was used for data collection and analysis, by using both qualitative (Interview and short-essay questions) and quantitative (Likert-scale questionnaires) data as main sources of data.

The Study sample included 645 participants, consisting of 30 English language teachers and 615 high school students from 13 public schools in the United Arab Emirates. The …

A Data Driven Model To Promote Preparedness And Respond Intelligently To Pandemic Outbreaks, Safea Mohammed Al Senani

Theses

The COVID-19 pandemic has had a major effect on various vital sectors of the economy, including education healthcare, and the industry. Governments have imposed strict regulations to reduce the spread of this global disease outbreak. Consequently, working from home, online learning, social distancing and various control measures were enforced. In response, many schools shifted to distance learning, although most of these schools were neither technically ready nor administratively prepared for the online transition. Despite recent progress, countries are still experiencing daunting challenges to control the infection rate and magnitude, stabilize the economy, and relax socialization and public life activities. Decision-makers …

Orbit Propagation And Determination Algorithms For Satellite Ground Stations, Shamma Esmaeel Jamali

Theses

The satellite orbital parameters are essential for satellite operations. With these parameters, it is possible to estimate the satellite position in the recent past and near future, which is essential to effectively plan satellite operations and associate satellite telemetry with geographical locations.
However, for small or medium satellite operators who do not possess the infrastructure required to track their satellites, the problem of determining the satellite orbit is problematic. To access the orbit for their satellites, these organizations have to rely on third parties such as Celestrak. These entities provide the service free of charge but do not provide orbital …

Valuation Of Options In A High Volatile Regime Switching Market, Tasnim Mazen Sharif Alhamad

Theses

Financial modeling by Stochastic Differential Equations-SDEs with regime-switching has been utilized to allow moving from one economic state to another. The aim of this thesis is to tackle the pricing of European options under a regime-switching model where the volatility is augmented. Regime-switching models are more realistic since they encompass the effect of an external event on the underlying asset prices. But they are challenging, considering in addition increased volatility in the model will for sure make the option pricing problem more complicated and its solution may not exist analytically. Numerical methods for finance could be very helpful in this …

The Impact Of Stem-Based Curriculum On The Development Of Creative Thinking Of High School Students In The United Arab Emirates, Rana Yousef Khalil

Theses

STEM-based curriculum is an integrated structure for teaching science, technology, engineering, and mathematics using project- and inquiry-based learning to produce creative outcomes. This study aims to assess the impact of STEM-based curriculum on the development of creative thinking of high school students while studying physics. Further, this study aims to assess the impact of students’ gender and grade level on the development of creative thinking after implementing a STEM-based curriculum. For this purpose, a quasi-experimental design was used to collect data using the Torrance Test of Creative Thinking (TTCT) and its metrics (fluency, elaboration, flexibility, and originality). In one of …

Toward Structural Characterization Of Broadacre Crops Using Uas-Based 3d Point Clouds, Fei Zhang

Theses

The use of unmanned aerial systems (UAS)-based remote sensing methods in precision agriculture (PA) has seen rapid development in recent years. These technologies are expected to revolutionize crop management by capturing imagery data with a high spatial, temporal, and spectral resolution, thereby enabling the decision-making of farm inputs at the sub-field level and on an almost daily basis. However, in real-world operational applications, the potential of UAS-based remote sensing methods has not yet been fully exploited. One of the main research avenues is that of structural characterization of crops in order to assess plant density, leaf density, i.e., overall crop …

Bayesian Estimation Of The Intensity Function Of A Non-Homogeneous Poisson Process, James Jensen

Theses

In this paper we explore Bayesian inference and its application to the problem of estimating the intensity function of a non-homogeneous Poisson process. These processes model the behavior of phenomena in which one or more events, known as arrivals, occur independently of one another over a certain period of time. We are concerned with the number of events occurring during particular time intervals across several realizations of the process. We show that given sufficient data, we are able to construct a piecewise-constant function which accurately estimates the mean rates on particular intervals. Further, we show that as we reduce these …

Detailing The Effects Of Cbd On Parp And Survivin Expression In Ewing Sarcoma, Tyler Carter

Theses

Ewing sarcoma (ES) is an aggressive pediatric bone cancer with low five-year survival rates, particularly with recurrent disease because ES often becomes resistant to chemotherapy in these recurrences. Cannabidiol (CBD) has been identified as a potentially promising therapeutic for patients with ES. In other cancer types, CBD has demonstrated effects on two major proteins that contribute to chemotherapy resistance. The first, Poly (ADP-ribose) Polymerase I (PARP1), is a DNA damage repair enzyme that is overexpressed in recurrent ES. Though chemotherapy induces DNA damage in these cancer cells, the high levels of PARP1 facilitate repair of the DNA, allowing the mutated …

Fraudulent Insurance Claims Detection Using Machine Learning, Arif Ismail Alrais

Theses

As the different countries around the world evolve into a more economical-based and stimulating their economy is the goal. The main purpose of most of these countries is to fight off money launderers and fraudsters for better economic growth. A popular fraud topic in this regard is insurance fraud since it costs the companies and the public billions. Applying data analysis and machine learning are great ways used to address many problems regarding any automated system. To address this problem, first extensive research should be made to check out what has been applied and what the most promising solution using …

A Hybrid Time-Series Pv Power Forecasting Model Implementing Facebook Prophet And Neural Prophet Algorithms, Afra Nasser Al Mansoori, Fatima Ahmed Al Ajami, Maha Ali Mousa

Theses

Globally, countries are limiting their dependency on conventional energy as their primary energy source. From this perspective, the ongoing integration of renewable energy sources with existing systems is the focus of researchers and power utilities. Photovoltaics (PV) is one of the leading solar technologies driving substantial growth in renewable energy applications. Consequently, power utilities are faced with large penetration of PV systems within the existing electrical grid. This ongoing integration introduces new electricity generation profiles, which raises technical challenges affecting grid reliability. Therefore, this work proposes building a PV power short-term forecasting model, which can avoid adverse outcomes of large …

Miniaturized Iii-V/ Si Hybrid Laser With An Integrated Modulator, Praveen Kumar Singaravelu

Theses

Light interaction with microscopic and nanoscopic structures enable manipulation of its characteristics which can be used to detect objects in 3D sensing, propel satellites to space using photonic propulsion and transmit data through optical communication. For optical communication, the basic components are lasers, modulators and photodetectors. The development of CMOS microfabrication foundries helps to manufacture silicon-based photonic devices with high yield that is directly co-integrated with electronics in a single chip. However, the lack of emission of photons efficiently in silicon propelled the necessity of hybrid photonic devices that inherits the combined advantage of different materials i.e. functionality and volume. …

Comparison Of Methane Plume Detection Using Shortwave And Longwave Infrared Hyperspectral Sensors Under Varying Environmental Conditions, Lucy Zimmerman

Theses

Methane is a prevalent greenhouse gas with potent heat trapping capabilities, but methane emissions can be difficult to detect and track. Hyperspectral imagery is an effective method of detection which can locate methane emission sources in order to mitigate leaks, as well as provide accountability for reaching emissions reduction goals. Because of methane’s absorption features in the infrared, both shortwave infrared (SWIR) and longwave infrared (LWIR) hyperspectral sensors have been used to accurately detect methane plumes. However, surface, environmental and atmospheric background conditions can cause methane detectability to vary. This study compared methane detectability under varying environmental conditions for two …

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …

Efficient And Scalable Triangle Centrality Algorithms In The Arkouda Framework, Joseph Thomas Patchett

Theses

Graph data structures provide a unique challenge for both analysis and algorithm development. These data structures are irregular in that memory accesses are not known a priori and accesses to these structures tend to lack locality.

Despite these challenges, graph data structures are a natural way to represent relationships between entities and to exhibit unique features about these relationships. The network created from these relationships can create unique local structures that can describe the behavior between members of these structures. Graphs can be analyzed in a number of different ways including at a high level in community detection and at …

Constraints On Compact Binary Formation And Effective Gravitational Wave Likelihood Approximation, Vera Del Favero

Theses

Since the initial discovery of gravitational-waves from merging black holes, the LIGO Scientific Collaboration together with Virgo and KAGRA have published 90 gravitational-wave observations of compact binary mergers in the Gravitational-Wave Transient Catalog papers. One of the quintessential questions of this decade in gravitational-wave astronomy is the characterization and impact of the population of observed gravitational-wave signals from merging black holes and neutron stars. Now, there is greater incentive than ever to study the formation channels for these compact binary mergers. In this work, we carry out an investigation of isolated binary evolution formation channel, comparing predictions of the gravitational-wave …

Integrated Framework For Analyzing Clean Energy Technology Subsidies, Tiruwork Berhanu Tibebu

Theses

Renewable energy technologies can significantly reduce fossil fuel consumption and greenhouse gas emissions associated with the energy sector. In US, both federal and state governments have implemented numerous policies and programs to support these technologies. But these policies require a substantial amount of public spending. In this study, an integrated model to identify optimal subsidy schedules for clean energy technologies that maximize social benefits less subsidy costs is developed. The national flexible optimal subsidy schedule for residential solar PV begins at $585/kW and declines to zero in 14 years. An alternative analytical model is also presented to analyze technological features …

Bayesian Inference And Prediction In Cardiac Electrophysiology Models With An Application To Representing Variability, Alejandro Nieto Ramos

Theses

Many different techniques have been used for parameter estimation in cardiac electrophysiology models, from optimization algorithms to heuristic and frequentist statistical methods. However, the fixed parameter values obtained from such approaches cannot provide a complete description of variability within an individual or across a population. To overcome this shortcoming, in this work we adopt a Bayesian approach by applying the Hamiltonian Monte Carlo (HMC) algorithm to cardiac electrophysiology models and data for the first time through three studies. (i) Using HMC, we fit synthetic and experimental cardiac voltage data from different pacing rates and find the probability distributions of the …

Acquisition Strategies For Gravitational Wave Surrogate Modeling, Karl Daningburg

Theses

Gravitational wave science is dependent upon expensive numerical simulations, which provide the foundational understanding of binary merger radiation needed to interpret observations of massive binary black holes. The high cost of these simulations limits large-scale campaigns to explore the binary black hole parameter space. Surrogate models have been developed to efficiently interpolate between simulation results, but these models require a sufficiently comprehensive sample to train on. Acquisition functions can be used to identify points in the domain for simulation. We develop a new acquisition function which accounts for the cost of simulating new points. We show that when applied to …

Infomixup : An Intuitive And Information-Driven Approach To Robust Generalization, Andrew H. Meyer

Theses

The discovery of Adversarial Examples — data points which are easily recognized by humans, but which fool artificial classifiers with ease, is relatively new in the world of machine learning. Corruptions imperceptible to the human eye are often sufficient to fool state of the art classifiers. The resolution of this problem has been the subject of a great deal of research in recent years as the prevalence of Deep Neural Networks grows in everyday systems. To this end, we propose InfoMixup , a novel method to improve the robustness of Deep Neural Networks without significantly affecting performance on clean samples. …

Impacts Of Spatial Resolution And Viewing Angle On Remotely Sensed Estimates Of Spartina Alterniflora Aboveground Biomass, Avery Miller

Theses

Coastal salt marshes sequester large quantities of “blue carbon” in plant biomass and sediments, and provide numerous other valuable ecosystem functions and services. However, these ecosystems are increasingly threatened by external stressors, including rising sea levels and a changing climate, which have resulted in large losses of tidal marsh habitat. Measuring plant biomass is critical for understanding how carbon storage may be affected as stressors continue to cause marsh losses, and for improving conservation and management efforts. A number of studies have quantified aboveground biomass (AGB) in salt marshes using remote sensing techniques, and with the development of high resolution …

The Earth Disk Model: Analysis And Integration Of Protoplanetary Disk Mineralogy And Structure, William Allen Richard Grimble

Theses

Our understanding of how exoplanets form and evolve relies on analyses of both the mineralogy of protoplanetary disks and their detailed structures; however, these key complementary aspects of disks are usually studied separately. We present initial results from a hybrid model that combines the empirical characterization of the mineralogy of a disk, as determined from its mid-infrared spectral features, with the well-tested MCFOST radiative transfer disk model that takes into account realistic disk density and temperature structures, a combination we call the EaRTH Disk Model. With the results of the mineralogy detection serving as input to the radiative transfer model, …

Investigating Kandinsky's Inspiration From Michelangelo Buonarroti, Asal F. Morvari

Theses

This study aims to analyze Kandinsky's The Last Judgment painting and compare it with Michelangelo's The Last Judgment to show that Michelangelo's work influenced Kandinsky's painting. For this study, the mixed-methods methodology is applied, which refers to an emergent methodology of research that advances the systematic integration or combining of quantitative and qualitative analysis within a single investigation. Mathematical analysis and a review of Kandinsky's books and manuscripts are considered. Image processing analysis is applied using biorthogonal Wavelet analysis and Canny Edge detection, in conjunction with Kandinsky's writings on color theory, to determine whether Kandinsky was inspired by Michelangelo's The …

Revisiting Ad-Hoc Polymorphism, Apurav Khare

Theses

Ad-hoc polymorphism is a type of polymorphism where different function definitions can be given the same name. Programming languages utilize constructs like Type classes and Object classes to provide a mechanism for implementing ad-hoc polymorphism. System O, by Odersky, Wadler, and Wehr is a language which defines a dynamic semantics that supports ad-hoc polymorphism. It also describes static type checking for its programs and a transformation to the Hindley/Milner system. In this study, we present extensions to System O by defining constructs that make the language more practical to use. We utilize the dynamic semantics to define the ability to …

Experimental Designs For Observing The Hong-Ou-Mandel Manifolds Using Silicon Micro-Ring Resonators, Joseph Monteleone Iii

Theses

We propose three experimental designs for observing the Hong-Ou-Mandel Manifolds using silicon micro-ring resonators. These experimental designs tackle the challenges of producing and coupling identical photon pairs to be incident on a silicon micro-ring resonator, and they describe methods of photon observation. We experimentally characterized a silicon micro-ring resonator with Mach-Zehnder Interferometer couplers. We modified the Hong-Ou-Mandel Manifold theory to include these realistic Mach-Zehnder Interferometer couplers, and computationally predict new manifold structures based on experimental power transmission spectrum comparisons. We also characterized a packaged foundry-fabricated silicon spiral photon pair source to be used as a possible identical photon pair source.