Digital Commons Network^™

Synthesizing Realistic Social Networks Using Personality Compatibility, Daniel Anthony O'Neil

Dissertations

Social structures and interpersonal relationships may be represented in abstract mathematical objects known as social networks. A social network consists of nodes corresponding to people and links between pairs of nodes corresponding to relationships between those people. Social networks can be constructed by examining groups of people and identifying the relationships of interest between them. There are circumstances where such empirical social networks are unavailable, or their use would be undesirable. Consequently, methods to generate synthetic social networks that are not identical to real-world networks but have desired structural similarities to them are valuable. A process for generating synthetic social …

Analysis And Mitigation Of Laser Frequency Drift And Its Application In Fiber-Optic Sensing, Dipen Barot

Dissertations

Ultralow-noise and ultra-stable sources of reference signals in the optical domain have become indispensable for applications such as precision measurements, optical sensing, optical frequency metrology, coherent optical communications, and microwave photonics. Such sources possess not only very narrow linewidth but also absolute frequency stability. Attaining high frequency stability in the optical domain requires innovative approaches to analyze and mitigate frequency noises and drifts. In this dissertation, a novel scheme of laser frequency analysis with improved specificity is proposed and demonstrated. The proposed method is based on power spectral density (PSD) measurement in the radio-frequency (RF) range aided by electronic frequency …

Development Of Low Stress, Broadband X-Ray Optic Multilayer Coatings, Danielle Nicole Gurgew

Dissertations

The design and development of an in-house X-ray optic multilayer coating deposition system and coating test facility has provided a substantial contribution to research and development of reflective X-ray optic coatings at NASA Marshall Space Flight Center (MSFC). An extensive validation study of the system's capabilities to deposit repeatable, multilayer reflective X-ray optic coatings of various complexities is discussed and the deposition of initial broadband multilayer coatings are presented. Additionally, a coating stress study has been conducted where intrinsic coating stress was measured and characterized for both periodic and depth-graded multilayer coatings. Several stress reduction techniques, post-deposition annealing and stress …

Local Supervised Methods And Uncertainty Quantification For Boundary Detection In Images, Margaret Coreen Lund

Dissertations

No abstract provided.

Is There A Correlation Between Wikidata Revisions And Trending Hashtags On Twitter?, Paula Dooley

Dissertations

Twitter is a microblogging application used by its members to interact and stay socially connected by sharing instant messages called tweets that are up to 280 characters long. Within these tweets, users can add hashtags to relate the message to a topic that is shared among users. Wikidata is a central knowledge base of information relying on its members and machines bots to keeping its content up to date. The data is stored in a highly structured format with the added SPARQL protocol and RDF Query Language (SPARQL) endpoint to allow users to query its knowledge base.

Forecasting Anomalous Events And Performance Correlation Analysis In Event Data, Sonya Leech [Thesis]

Dissertations

Classical and Deep Learning methods are quite common approaches for anomaly detection. Extensive research has been conducted on single point anomalies. Collective anomalies that occur over a set of two or more durations are less likely to happen by chance than that of a single point anomaly. Being able to observe and predict these anomalous events may reduce the risk of a server’s performance. This paper presents a comparative analysis into time-series forecasting of collective anomalous events using two procedures. One is a classical SARIMA model and the other is a deep learning Long-Short Term Memory (LSTM) model. It then …

Laying The Foundation To Improve Literacy In A K-12 Islamic School Through The Introduction Of A Professional Learning Community: A Formative Evaluation, Hanan Matari, Ruqia Ali

Dissertations

To improve professional development, a professional learning community (PLC) was initiated at a small, K–12 Islamic school in northwest suburban Chicago, IL. This evaluation describes and assesses the initiation and year-one implementation of the PLC, and focuses on teachers’ literacy instruction skills. A formative evaluation approach was used to monitor and assess progress and encourage teachers’ ownership of their learning. Teachers collaborated in large and smaller grade or subject area PLC groups to identify, chart, and implement new teaching strategies under peer observation for feedback. Teachers succeeded in establishing school-wide literacy strategies; however, issues challenged the PLC’s future—time, resources, and …

Explicitly Teaching Scientific Argumentation: Using Action Research To Study High School Science Readiness And Detracking, Ami Lefevre

Dissertations

Access to advanced-level science courses can be difficult for those students who start in a tracked system. Tracking is an educational practice where students are assigned to different classes based on ability level. African American and Hispanic students are most at risk since most minority students are found in the lower level track (Burris, 2014; Mehan, 2015; Oakes, 2005). This investigation used an action research approach to determine how explicitly taught elements of scientific argumentation would impact student mastery of argument skills and influence instructional practices by a professional learning community. A mixed method study was used to collect qualitative …

Perceptions Of High School Principals Of The Role Of Multi-Tiered Systems Of Support-- Formally Rti-- In Bringing About Social Justice And Equity For Black Boys, La Wanna Marie Wells

Dissertations

Historically, Black males are disproportionately represented as the least likely to graduate at every level of education and the demographic most likely placed in Special Education courses, incarcerated, as victims of homicide and who live in poverty. The United States of America implemented a voluntary program, Multi-tiered Systems of Support for educators to "intervene" with proactive measures that target groups that systemically fail: students of color, English learners, students with disabilities and the poor. The purpose of this research is to observe the perceptions of school principals who have implemented Multi-tiered Systems of Support (MTSS) as an education program for …

Measuring And Evaluating Directional Textures And Using Them In Visual Discovery, Manil Maskey

Dissertations

This dissertation focuses on three aspects of directional textures. The first aspect is the development of a new directional texture-based visualization technique to address challenges in visualizing multivariate data in a single display. The technique uses a multi level Markov Random Field-based texture synthesis to progressively generate a visualization that encodes data variables using various texture features, especially texture direction. Since texture directionality has not been used extensively in visualization, this technique provides a new visual cue to display additional data variable in a single display. Evaluations of the new texture-based visualization technique are also presented. The second aspect is …

Parallel Implementation Of Resampling Methods For Particle Filtering On Graphics Processing Units, Matthew A. Nicely

Dissertations

Particle filter techniques are common methods used to estimate the evolving state of nonlinear, non-Gaussian time-variant systems by utilizing a periodic sequence of noisy measurements. The accuracy of particle filtering has often been shown to be superior to other state estimation techniques, such as the extended Kalman filter (EKF), for many applications. Unfortunately, the high computational cost and highly nondeterministic run-time behavior of particle filters often precludes their use in hard, real-time environments where filter response must meet the strict timing requirements of the application. Particle filter algorithms are composed of three main stages: prediction, update, and resampling. General purpose …

Hybrid Impulsive Higher Order Sliding Mode Control, Fathi Muhammad Aldukali

Dissertations

A hybrid-impulsive second order/higher order sliding mode (2- SMC/HOSM) control is explored in order to reduce dramatically the convergence time practically to zero, achieving instantaneous (or short time) convergence and uniformity. For systems of relative degree 2, the impulsive portion of the control function drives the system’s output (the sliding variable) and it’s derivative to zero instantaneously (or in short time) achieving a uniform convergence. Then the discontinuous state or output feedback stabilizes system’s trajectory at the origin (or its close vicinity), while achieving the ideal or real second order sliding mode (2-SM). The Lyapunov analysis of the considered hybrid-impulsive-discontinuous …

Physically Derived Two-Dimensional Predictive Model For Dual-Gate Devices Using Quintic Splines, Scott C. Wolfson

Dissertations

This dissertation presents the first ever application of quintic splines in the development of a dual-gate Metal Oxide Semiconductor Field Effect Transistor (MOSFET) model based on the well-known drift-diffusion system of differential equations. The techniques and methodologies presented advance the current state of the art in this particular area by implementing improved two-dimensional numerical techniques and limiting the use of common accuracy reducing assumptions intended to decrease semiconductor equation complexity and simulation execution time. This results in the first known two-dimensional physics based model that uses this numerical technique, is valid in all regions of operation, includes Non-Quasi Static transient …

A Theoretical Evaluation Of Engineering Conceptual Design Methodologies, John M. Nicholson

Dissertations

Much of Systems Engineering (SE) involves heuristic tools and rules of thumb to aid the engineer in making decisions. Practicing engineers rely on these heuristic methods to manage risk, plan and perform tests, plan projects and design products. Product design is the focus of this research. Numerous product design methods in practice utilize heuristics and simplifying assumptions to ease the burden on the design engineer. However, do engineers pay a price for these simplifications? To understand the impact of design methods, a normative design framework is developed based on a rigorous consideration of Decision Theory and Social Choice Theory. Engineers …

Understanding The Significant Disparity Between Observations And Cmip5 Model Simulations At The Ocean/Atmosphere Interface In The Tropics, Robert Anthony Junod

Dissertations

Observations indicate that the warming of the tropical atmosphere is proceeding at a rate significantly less than depicted in model projections. Surface energy fluxes play a central role in the coupling of the atmosphere and ocean components which impact tropospheric temperature. In order to investigate the atmospheric temperature disparity, this study examines the near-surface air temperature and surface energy fluxes at the ocean-atmosphere interface using a suite of Coupled Model Intercomparison Project 5 (CMIP5) models, comparing their output with observations. Observations are used to test model fidelity with respect to the surface energy fluxes (net shortwave, net longwave, latent heat …

Ion-Atom Charge-Exchange Collisions And Their Effect On Plasma-Neutral Coupling, Anthony M. Destefano

Dissertations

The heliosphere is a cavity carved out of the interstellar medium by the supersonic outflow of solar wind (SW) from the Sun. The local interstellar medium (LISM) is partially ionized with the neutral particles penetrating the heliosphere unimpeded by the electric and magnetic (EM) fields. In order to model the heliosphere, both a magnetohydrodynamic (MHD) and a kinetic Boltzmann (or fluid) approach should be used to represent the plasma and neutral particles, respectively. Even though neutral particles are unaffected by EM fields, certain collisions that exchange charge between ions do occur called charge-exchange. This charge-exchange process, in the form of …

Detection Of Offensive Youtube Comments, A Performance Comparison Of Deep Learning Approaches, Priyam Bansal

Dissertations

Social media data is open, free and available in massive quantities. However, there is a significant limitation in making sense of this data because of its high volume, variety, uncertain veracity, velocity, value and variability. This work provides a comprehensive framework of text processing and analysis performed on YouTube comments having offensive and non-offensive contents.

YouTube is a platform where every age group of people logs in and finds the type of content that most appeals to them. Apart from this, a massive increase in the use of offensive language has been apparent. As there are massive volume of new …

School Principal's Leadership Style And Teacher's Self-Efficacy In High And Low Achieving Schools In Chikankata, Zambia, Pardon Mwansa

Dissertations

Problem and Purpose

Much research has been done in past years on the topic of student achievement, with most of those studies focusing on factors that contribute to student achievement. Little, or no research has been done, especially in the country of Zambia, that has focused on the relationship between leadership style, teacher self-efficacy, and the extent to which these constructs impact student achievement. This study explored the school principals' leadership style, teacher self-efficacy, and the extent to which these factors contribute to student achievement in Chikankata District, Zambia. The Ministry of Education in Zambia and other educators, especially those …

Archaeological Backgrounds Of The Sanctuary: A Search For Egyptian Cultural Influence In The Construction Of The Hebrew Tent-Sanctuary, Leslie Scott Baker Jr

Dissertations

Problem

Although the documented description of the construction of the tent-sanctuary appears to give it an Egyptian context in terms of the materials used and the culture of the artisans, in three distinct spheres (sacred, royal-domestic, and military), very little work has been done in comparing the descriptions in the text with the recovered archaeological fabric from Egypt and no study has, as yet, taken the next step of quantifying that comparison through a potentially-repeatable statistical analysis in an effort to determine, in an unbiased manner, the nature of the relationship.

Method

Design and frequency data of the appearing materials …

Working Memory And Attention As Predictors Of Processing Speed In Elementary School Students: A Developmental Study, Monih Alshehri

Dissertations

Problem

Many studies suggest that Processing Speed (PS), Attention, and Working Memory (WM) are major cognitive functions that collaborate to achieve a coherent cognitive system. The aim of the current study was to improve the conception of how these cognitive functions interrelate. The study addressed two main questions: the first, whether PS can be predicted by WM (visual, verbal, and the central executive) and attention of elementary students in first and fifth grade; the second, whether there are gender differences in the rate of change in WM and PS from first to fifth grade.

Method

The participants were taken from …

Teacher Preparation And English Language Learners: The Negotiation Of Teaching Identities In Communities Of Practice, Eleni Giatsou

Dissertations

This dissertation unveils the identity formation and negotiation processes of teacher candidates, through their practice with English Language Learners (ELLs) in a field-based teacher preparation program. Identity, like learning, is socially constructed and continuously negotiated by someone's engagement in a community (Wenger, 1998). Thus, sociocultural theory and specifically the theoretical construct of communities of practice (Wenger, 1998), guided the exploration of candidates' teaching identities to reveal the processes of becoming a teacher of ELLs. I conducted a qualitative case study to examine candidates' teaching practices with ELLs at a surface level and the (re)construction of their teaching identities at a …

My Role As An Administrator In Supporting The Implementation Of Mtss (Multi-Tiered Systems Of Supports) Tier 3 Students: A Self-Study In A Public School System, Terrycita Delight Perry

Dissertations

For approximately three years, the Chicago Public School (CPS) district has been undergoing a process of creating protocols, structures, and tools that will assist schools with the implementation of multi-tiered systems of support (MTSS). An on-going area of development for the district as well as for my school is developing teachers' abilities to support all students in the leveled tiers, particularly Tier 3. The purpose of this self-study is to understand, document, and analyze my actions (as the principal) while implementing MTSS Tier 3 (K-3) supports at my school. A self-study is a form of research educators use to understand …

Analyzing Twitter Feeds To Facilitate Crises Informatics And Disaster Response During Mass Emergencies, Arshdeep Kaur

Dissertations

It is a common practice these days for general public to use various micro-blogging platforms, predominantly Twitter, to share ideas, opinions and information about things and life. Twitter is also being increasingly used as a popular source of information sharing during natural disasters and mass emergencies to update and communicate the extent of the geographic phenomena, report the affected population and casualties, request or provide volunteering services and to share the status of disaster recovery process initiated by humanitarian-aid and disaster-management organizations. Recent research in this area has affirmed the potential use of such social media data for various disaster …

Comparing Procedural Content Generation Algorithms For Creating Levels In Video Games, Zina Monaghan

Dissertations

Procedural Content Generation (PCG) is used frequently in games to increase replayability by introducing variety to playghrough of a game and reduce development time by allowing complex game worlds to be developed by a smaller team over a more limited amount of time.

An Evaluation Of The Information Security Awareness Of University Students, Alan Pike

Dissertations

Between January 2017 and March 2018, it is estimated that more than 1.9 billion personal and sensitive data records were compromised online. The average cost of a data breach in 2018 was reported to be in the region of US$3.62 million. These figures alone highlight the need for computer users to have a high level of information security awareness (ISA). This research was conducted to establish the ISA of students in a university. There were three aspects to this piece of research. The first was to review and analyse the security habits of students in terms of their own personal …

An Investigation Into The Predictive Capability Of Customer Spending In Modelling Mortgage Default, Donal Finn [Thesis]

Dissertations

The mortgage arrears crisis in Ireland was and is among the most severe experienced on record and although there has been a decreasing trend in the number of mortgages in default in the past four years, it still continues to cause distress to borrowers and vulnerabilities to lenders. There are indications that one of the main factors associated with mortgage default is loan affordability, of which the level of disposable income is a driver. Additionally, guidelines set out by the European Central Bank instructed financial institutions to adopt measures to further reduce and prevent loans defaulting, including the implementation and …

Noise Reduction In Eeg Signals Using Convolutional Autoencoding Techniques, Conor Hanrahan

Dissertations

The presence of noise in electroencephalography (EEG) signals can significantly reduce the accuracy of the analysis of the signal. This study assesses to what extent stacked autoencoders designed using one-dimensional convolutional neural network layers can reduce noise in EEG signals. The EEG signals, obtained from 81 people, were processed by a two-layer one-dimensional convolutional autoencoder (CAE), whom performed 3 independent button pressing tasks. The signal-to-noise ratios (SNRs) of the signals before and after processing were calculated and the distributions of the SNRs were compared. The performance of the model was compared to noise reduction performance of Principal Component Analysis, with …

Promotion And Retention Of English Learners (Ells) In An Large Urban School District: A Policy Advocacy Document, Hanan Matari, Ruqia Ali

Dissertations

This policy advocacy document argues for a fair and equitable retention and promotion policy for English language learners (ELLs) in elementary grades of a large urban school district. Increasing access and instructional opportunities within bilingual/ESL services combined with more accurate measures of English proficiency would help mitigate random or unfair promotion and retention practices. A needs analysis was conducted on educational, economic, social, political, and moral-ethical dimensions and arguments made in support of the recommended policy (Browder, 1995). This policy solidifies district accountability for the education of all ELL students by mandating schools provide equal opportunity and access to high-quality …

Domain Decomposition Methods For The Solution Of Multiple Scattering Problems, Michael Pedneault

Dissertations

This presents a Schur complement Domain Decomposition (DD) algorithm for the solution of frequency domain multiple scattering problems. Just as in the classical DD methods,(1) the ensemble of scatterers is enclosed in a domain bounded by an artificial boundary, (2) this domain is subdivided into a collection of nonoverlapping subdomains so that the boundaries of the subdomains do not intersect any of the scatterers, and (3) the solutions of the subproblems are connected via Robin boundary conditions matching on the common interfaces between subdomains. Subdomain Robin-to-Robin maps are used to recast the DD problem as a sparse linear system whose …

Impairments In Ground Moving Target Indicator (Gmti) Radar, Phuoc Doan Huu Vu

Dissertations

Radars on multiple distributed airborne or ground based moving platforms are of increasing interest, since they can be deployed in close proximity to the event under investigation and thus offer remarkable sensing opportunities. Ground moving target indicator (GMTI) detects and localizes moving targets in the presence of ground clutter and other interference sources. Space-time adaptive processing (STAP) implemented with antenna arrays has been a classical approach to clutter cancellation in airborne radar. One of the challenges with STAP is that the minimum detectable velocity (MDV) of targets is a function of the baseline of the antenna array: the larger the …