Digital Commons Network^™

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 …

“The Zero To Three Years Are So Important” An Exploration Of The Needs Of Young Children In Ecec Settings From A Policy And Practice Perspective., Rosemary Brien

Dissertations

A strong body of evidence demonstrates that young children under the age of three are experiencing a critical period in their development which impacts long term mental and physical health. Responsive, secure and positive relationships between young children and their caregivers is integral to healthy social and emotional development.The principle aim of this study is to explore how the needs of children under the age of three are perceived and addressed in Irish early childhood education and care settings from a practice and policy perspective.A qualitative research approach was adopted utilising semi-structured interviews with managers of full day care settings …

An Exploration Of Managers’ Perspectives On Their Role In Managing Community Early Years Services : Influences And Insights, Jessica Lee

Dissertations

This exploration into theperspectives of managers of community Early Years services stems from the absence of a requirement of a qualification for supernumerary managers in Early Years services in Ireland and the resulting ambiguity of definedfunctions of such managers and contextually specific requirements. The aim of the study is to gain a deep insight into the perspectives ofthe participants on their roles in leading and managing their services. The objectives are to understand what internal and external factors have shaped their roles, to locate the dichotomies and harmonies between what iscontextuallyrequired of managersand what the true reality of a manager’s …

Analysis Of Acoustic Emission Signals In Aluminum And Composite Structures, Duy Quang Tran

Dissertations

Acoustic emission signal in aluminum plates and composite specimens are examined in this dissertation. The first part of the dissertation examines the symmetric lamb wave modes generated by the spontaneous appearance of a central microcrack in an aluminum plate. The detected acoustic emission amplitude of these waves with radial and angular position of the sensing location was analyzed using finite element analysis. An important aspect of this study is the detailed characterization of the shear horizontal mode of the Lamb wave that is generated by simulated crack growth. This analysis indicates that the amplitude of the shear horizontal mode remains …

Improving School Culture To Enhance Academic Achievement At Samad Islamic School: A Change Leadership Plan, Hanan Matari, Ruqia Ali

Dissertations

The purpose of this leadership change plan was to understand the influence of Samad School’s culture on students’ academic achievement. The goal was to help Samad Islamic School to develop and follow an action plan to improve school culture. Wagner et al.’s (2006) 4C’s change leadership model was used to analyze four dimensions of the school: context, conditions, competencies, and culture. An adapted version of the School Culture Triage Survey was used to collect data. Survey results were presented to and discussed among teachers in both large and small group settings followed by written individual teacher reflections on the process. …

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 …

Interrogation Of Epigenetic And Genetic Determinants Of Complex Diseases, Megan Elizabeth Breitbach

Dissertations

No abstract provided.

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

Dissertations

No abstract provided.

Attack Reconstruction And Secure State Estimation In Cyber-Physical Systems Using Sliding Mode Observers, Shamila Nateghiboroujeni

Dissertations

No abstract provided.

An Industrially Applicable Approach To Transient Thermal Modeling In Additive Manufacturing Using A Mass-Added Finite Difference Method, Tom James Stockman Iii

Dissertations

No abstract provided.

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 …

Wireless Coverage Using Unmanned Aerial Vehicles, Hazim Shakhatreh

Dissertations

The use of unmanned aerial vehicles (UAVs) is growing rapidly across many civilian application domains including real-time monitoring, search and rescue, and wireless coverage. UAVs can be used to provide wireless coverage during emergency cases where each UAV serves as an aerial wireless base station when the cellular network goes down. They can also be used to supplement the ground base station in order to provide better coverage and higher data rates for the users. During such situations, the UAVs need to return periodically to a charging station for recharging, due to their limited battery capacity. Given the recharging requirements, …

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 …

Optimizing Resource Allocation In Eh-Enabled Internet Of Things, Ali Shahini

Dissertations

Internet of Things (IoT) aims to bridge everyday physical objects via the Internet. Traditional energy-constrained wireless devices are powered by fixed energy sources like batteries, but they may require frequent battery replacements or recharging. Wireless Energy Harvesting (EH), as a promising solution, can potentially eliminate the need of recharging or replacing the batteries. Unlike other types of green energy sources, wireless EH does not depend on nature and is thus a reliable source of energy for charging devices. Meanwhile, the rapid growth of IoT devices and wireless applications is likely to demand for more operating frequency bands. Although the frequency …

Characterization Of Self-Heating Effects And Assessment Of Its Impact On Reliability In Finfet Technology, Peter Christopher Paliwoda

Dissertations

The systematically growing power (heat) dissipation in CMOS transistors with each successive technology node is reaching levels which could impact its reliable operation. The emergence of technologies such as bulk/SOI FinFETs has dramatically confined the heat in the device channel due to its vertical geometry and it is expected to further exacerbate with gate-all-around transistors.

This work studies heat generation in the channel of semiconductor devices and measures its dissipation by means of wafer level characterization and predictive thermal simulation. The experimental work is based on several existing device thermometry techniques to which additional layout improvements are made in state …

Load Balancing And Scalable Clos-Network Packet Switches, Oladele Theophilus Sule

Dissertations

In this dissertation three load-balancing Clos-network packet switches that attain 100% throughput and forward cells in sequence are introduced. The configuration schemes and the in-sequence forwarding mechanisms devised for these switches are also introduced. Also proposed is the use of matrix analysis as a tool for throughput analysis.

In Chapter 2, a configuration scheme for a load-balancing Clos-network packet switch that has split central modules and buffers in between the split modules is introduced. This switch is called split-central-buffered Load-Balancing Clos-network (LBC) switch and it is cell based. The switch has four stages, namely input, central-input, central-output, and output stages. …

The Cooperative Effects Of Channel Length-Bias, Width Asymmetry, Gradient Steepness, And Contact-Guidance On Fibroblasts’ Directional Decision Making, Quang Long Pham

Dissertations

Cell migration in complex micro-environments, that are similar to tissue pores, is important for predicting locations of tissue nucleation and optimizing scaffold architectures. Firstly, how fibroblast cells - relevant to tissue engineering, affect each other’s directional decisions when encountered with a bifurcation of different channel lengths was investigated. It was found that cell sequence and cell mitosis influence the directional choices that the cells made while chemotaxing. Specifically, the fibroblasts chose to alternate between two possible paths - one longer and the other shorter - at a bifurcation. This finding was counter-intuitive given that the shorter path had a steeper …

Magnetic Field Assisted Milli-Scale Robotic Assembly Machine: An Approach To Massively Parallel Swarm Robotic Automation Systems, Yan Liu

Dissertations

The vision of highly parallel, automated manufacturing systems that can build macroscopic products by heterogeneous assembly of many small devices will have a major impact in manufacturing. In this study, a novel milli-scale robotic assembly machine with parallel capabilities, assisted with programmable magnetic field, is developed. The machine prototype consists of a 16x16 array of electromagnets. The dimensions of the electromagnets are 5mm high with an inner diameter of 1.1mm and outer diameter of 2.5mm. All the electromagnets are driven by a 16x16 array of H-Bridges, and an Arduino microcontroller is used to control and program the arrays.

Using the …

Storage Systems For Mobile-Cloud Applications, Nafize R. Paiker

Dissertations

Mobile devices have become the major computing platform in todays world. However, some apps on mobile devices still suffer from insufficient computing and energy resources. A key solution is to offload resource-demanding computing tasks from mobile devices to the cloud. This leads to a scenario where computing tasks in the same application run concurrently on both the mobile device and the cloud.

This dissertation aims to ensure that the tasks in a mobile app that employs offloading can access and share files concurrently on the mobile and the cloud in a manner that is efficient, consistent, and transparent to locations. …

Methods To Improve The Remediation Of Polycyclic Aromatic Hydrocarbons (Pahs) In Aerobic And Anaerobic Environments, Brian Wartell

Dissertations

Oil spills occur regularly in terrestrial environments and crude oil can contain many compounds that are highly resistant to degradation. Among these compounds are high levels of polycyclic aromatic hydrocarbons (PAHs) which are not only toxic but can also be carcinogenic and/or mutagenic. The first chapter of this dissertation includes an extensive review chapter on the variables affecting the anaerobic degradation of hydrocarbons, with a particular focus on PAHs. Electron acceptors, electron donors, temperature, salinity, pH all play key roles in determining the possibility effective of effective degradation occurring. Thus, by addressing solutions, such as biostimulation, improving environmental variables for …

High-Speed Data Communications For Vehicular Networks Using Free-Space Optical Communications, Yagiz Kaymak

Dissertations

The demand for high-speed Internet access for vehicles, such as high-speed trains (HSTs) and cars, is on the rise. Several Internet access technologies that use radio frequency are being considered for vehicular networking. Radio-frequency communications technologies cannot provide high data rates due to interference, bandwidth limitations, and the inherent limited data rates of radio technology. Free-space optical communications (FSOC) is an alternative approach and a line-of-sight (LOS) technology that uses modulated light to transfer data between two free-space optical (FSO) transceivers. FSOC systems for vehicular networks are expected to provide data rates in the range of Gbps for stationary and …

Experimental And Numerical Characterization Of Multiphase Subsurface Oil Release, Feng Gao

Dissertations

Subsurface oil release is commonly encountered in the natural environment and engineering applications and has received the substantial attention of researchers after the disastrous Deepwater Horizon Blowout oil spill in 2009. The main focus on the present research is to systematically study the hydrodynamics of underwater oil jet under a variety of conditions, including the effect of dispersant and different gas to oil ratios (GOR) by using experimental measurement as well as a Computational Fluid Dynamics (CFD) approach, from which the measured turbulent characteristics (e.g., velocity, turbulent kinetic energy, turbulence dissipation rate, etc.) of underwater oil jet are thoroughly examined …

Fwer Controlling Procedures In Simultaneous And Selective Inference, Li Yu

Dissertations

With increasing complexity of research objectives in clinical trials, a variety of relatively complex and less intuitive multiple testing procedures (MTPs) have been developed and applied in clinical data analysis. In order to make testing strategies more explicit and intuitive to communicate with non-statisticians, several flexible and powerful graphical approaches have recently been introduced in the literature for developing and visualizing newer MTPs. Nevertheless, some theoretical as well as methodological issues still remain to be fully addressed. This dissertation addresses several important issues arising in graphical approaches and related selective inference problems. It consists of three parts.

In the first …

Functionalized Carbon Nanotubes In Hydrophobic Drug Delivery, Kun Chen

Dissertations

The direct incorporation of carboxylated carbon nanotubes (f-CNTs) into hydrophobic drug particles during their formation via anti-solvent precipitation is presented. The approach is tested using two drugs namely antifungal agent Griseofulvin (GF) and antibiotic Sulfamethoxazole (SMZ) that have very different aqueous solubility. It is observed that the f-CNTs dispersed in the water serve as nucleating sites for crystallization and are readily incorporated into the drug particles without altering crystal structure or other properties. The results show that the hydrophilic f-CNTs dramatically enhance dissolution rate for both drugs. The increased degree of functionalization leads to higher hydrophilicity and therefore faster dissolution …

Deep Learning Methods For Mining Genomic Sequence Patterns, Xin Gao

Dissertations

Nowadays, with the growing availability of large-scale genomic datasets and advanced computational techniques, more and more data-driven computational methods have been developed to analyze genomic data and help to solve incompletely understood biological problems. Among them, deep learning methods, have been proposed to automatically learn and recognize the functional activity of DNA sequences from genomics data. Techniques for efficient mining genomic sequence pattern will help to improve our understanding of gene regulation, and thus accelerate our progress toward using personal genomes in medicine.

This dissertation focuses on the development of deep learning methods for mining genomic sequences. First, we compare …

Cardiac Regenerative Medicine: Insights From Healthy And Diseased Engineered Tissues, Pamela Grace Hitscherich

Dissertations

Cardiovascular disease remains the leading cause of mortality in the United States. Current tissue engineering approaches have fallen short of promoting fully functional cardiovascular cells and the post-myocardial infarction microenvironment is still not well understood. These gaps in knowledge are addressed in this dissertation through the development of in vitro engineered cardiac tissues using electroactive materials to enhance the differentiation of pluripotent stem cell derived cardiomyocytes and through the development of in vitro myocardial inflammation models dedicated to understanding cardiomyocytes and macrophages interactions.

Specifically, piezoelectric poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) supports the attachment and survival of mouse embryonic stem cell derived …

Development Of Flexible Nickel-Zinc And Nickel-Iron Batteries, Xianyang Meng

Dissertations

The fabrication of flexible nickel-zinc batteries using a facile mixing of electroactive components for electrode preparation is presented. Polytetrafluoroethylene (PTFE) is found to be an effective binder by reducing concentration polarization, providing chemical/physical stability and enhancing flexibility. The zinc electrode containing PTFE maintains its original porous morphology even after hundreds of cycles while polymers such as PEO show morphology change. Each component, as well as the assembled flexible cells show desired flexibility and stability even under bending conditions.

The fabrication of flexible nickel-iron batteries using printable composite electrodes embedded with multiwalled carbon nanotubes (CNT) is also presented. All the metal …

Computational Intelligence In Steganography: Adaptive Image Watermarking, Xin Zhong

Dissertations

Digital image watermarking, as an extension of traditional steganography, refers to the process of hiding certain messages into cover images. The transport image, called marked-image or stego-image, conveys the hidden messages while appears visibly similar to the cover-image. Therefore, image watermarking enables various applications such as copyright protection and covert communication. In a watermarking scheme, fidelity, capacity and robustness are considered as crucial factors, where fidelity measures the similarity between the cover- and marked-images, capacity measures the maximum amount of watermark that can be embedded, and robustness concerns the watermark extraction under attacks on the marked-image. Watermarking techniques are often …