Digital Commons Network^™

Methodology For The Integration Of Optomechanical System Software Models With A Radiative Transfer Image Simulation Model, Keegan S. Mccoy

Theses

Stray light, any unwanted radiation that reaches the focal plane of an optical system, reduces image contrast, creates false signals or obscures faint ones, and ultimately degrades radiometric accuracy. These detrimental effects can have a profound impact on the usability of collected Earth-observing remote sensing data, which must be radiometrically calibrated to be useful for scientific applications. Understanding the full impact of stray light on data scientific utility is of particular concern for lower cost, more compact imaging systems, which inherently provide fewer opportunities for stray light control. To address these concerns, this research presents a general methodology for integrating …

Annealing Of Fused Filament Fabricated Nylon 6 With Elevated Isostatic Pressure, Anthony G. Tantillo

Theses

Fused filament fabrication (FFF) is the most common form of 3D-printing used today. It combines ease-of-use with broad material options that allow for a wide spectrum of applications. Parts made this way are still considered only prototypes due to their relatively weak strength as compared to traditional manufacturing methods. Two factors leading to a decrease in strength are the interior voids and poor bonding roads. A chamber was created to implement pressurized annealing cycles on nylon 6 co-polymer parts to decrease interior voids and increase road bonding. A designed experiment was used to determine main effect parameter estimates for five …

Numerical Model To Predict Hemolysis And Transport In A Membrane-Based Microfluidic Device, Matthew D. Poskus

Theses

Microfluidics has become an increasingly popular tool in the design and development of medical devices and artificial organs. Two promising applications of microfluidics are dialyzers and oxygenators. As a step toward portable dialysis treatment, continuous microfluidic dialysis may resolve many clinical issues with current dialysis treatments. Additionally, commercially available oxygenators exceed the blood volume of neonatal patients; low-volume microfluidic devices may safely deliver oxygen to these patients. Two critical parameters in the development of these devices is mechanical hemolysis and membrane diffusion, which are intricately connected to the geometry, flow rate, properties of the membrane, and each other. A computational …

Task Scheduling Balancing User Experience And Resource Utilization On Cloud, Sultan Mira

Theses

Cloud computing has been gaining undeniable popularity over the last few years. Among many techniques enabling cloud computing, task scheduling plays a critical role in both efficient resource utilization for cloud service providers and providing an excellent user experience to the clients. In this study, we proposed a priority cloud task scheduling approach that considers users input to calculate priority, while at the same time, efficiently utilizes available resources. This approach is designed for the consideration of both user satisfaction and utilization of cloud services. In the proposed approach, clients will be required to input their time and cost preferences …

Automatic Cancer Tissue Detection Using Multispectral Photoacoustic Imaging, Kamal Jnawali

Theses

Convolutional neural networks (CNNs) have become increasingly popular in recent years because of their ability to tackle complex learning problems such as object detection, and object localization. They are being used for a variety of tasks, such as tissue abnormalities detection and localization, with an accuracy that comes close to the level of human predictive performance in medical imaging. The success is primarily due to the ability of CNNs to extract the discriminant features at multiple levels of abstraction.

Photoacoustic (PA) imaging is a promising new modality that is gaining significant clinical potential. The availability of a large dataset of …

An Exploration Of Emirati Parents’ Involvement In Their Children’S English Reading Of Primary Grades: A Mixed-Method Study, Shaikha Mohammed Ali Saeed

Theses

This study aimed at exploring the Emirati parents’ involvement in their children’s English reading in primary grades (1 through 3). The Study used an Explanatory Sequential Mixed Method Design. In the first phase of the study, a questionnaire (PIQ) was distributed to parents (n=498) who have children in those grades. In the second phase of the study, parents (n=10) were interviewed with regards to their involvement with their children in English language reading. The study found that: Parents have high involvement in their children’s English reading. Parents also reported high involvement in terms of communication, followed by involvement in academic …

Design Of A Multiband Stacked Microstrip Patch Antenna For Satellite Communications Application, Hadef Ahmed Alshamsi

Theses

In this thesis, a multiband stacked patch antenna for satellite communications is proposed. Since handheld devices used for satellite communications are mainly monopole antennas, this thesis explores the possibilities of developing a microstrip patch antenna that can be integrated in the satellite communications’ handheld devices. Therefore, a designed antenna for satellite communications that operates around the two bands 1.487 GHz and 1.578 GHz is proposed. The antenna composes of two stacked patches with total dimensions of 45 x 45 mm and 40 x 40 mm for the lower and upper patches, respectively, separated by FR_4 as a dielectric material. The …

Exploring The Effectiveness Of Privacy Preserving Classification In Convolutional Neural Networks, Prathibha Rama

Theses

A front-runner in modern technological advancement, machine learning relies heavily on the use of personal data. It follows that, when assessing the scope of confidentiality for machine learning models, understanding the potential role of encryption is critical. Convolutional Neural Networks (CNN) are a subset of artificial feed-forward neural networks tailored specifically for image recognition and classification. As the popularity of CNN increases, so too does the need for privacy preserving classification. Homomorphic Encryption (HE) refers to a cryptographic system that allows for computation on encrypted data to obtain an encrypted result such that, when decrypted, the result is the same …

Joint Source-Channel Coding For Image Transmission Over Underlay Multichannel Cognitive Radio Networks, Long Pham

Theses

The increasing prominence of wireless applications exacerbates the problem of radio spectrum scarcity and promotes the usage of Cognitive Radio (CR) in wireless networks. With underlay dynamic spectrum access, CRs can operate alongside Primary Users, the incumbent of a spectrum band, as long as they limit the interference to the Primary Users below a certain threshold. Multimedia streaming transmissions face stringent Quality of Services constraints on top of the CR interference constraints, as some packets in the data stream have higher levels of importance and are the most vulnerable to packet loss over the channel. This raises a need for …

Adding Renewables To The Grid: Effects Of Storage And Stochastic Forecasting, Naga Srujana Goteti

Theses

The electricity sector contributes to a quarter of global greenhouse emissions, and managing its evolution is a critical sustainability challenge. The context for the development and operation of electricity grids has dramatically changed in recent years. Wind and solar power have become much less expensive. Lower costs combined with increased policy action to address carbon emissions is leading to substantial shares of electricity generated by intermittent renewables. Maintaining a stable electricity supply with intermittency is a critical challenge; storage and natural gas are possible solutions. While policymakers promote storage as green grid technology, low-cost natural gas from hydrofracturing extraction raises …

An Exploration Of Microaggression Awareness In Real-Time Conversations And Long-Term Tracking And Learning System, Feifei Guo

Theses

Microaggression is a comment or action that subtly and often unconsciously or unintentionally expresses a prejudiced attitude toward a member of a marginalized group. Microaggressions are often subtle and ambiguous, it's often hard to know if you're committing one or if you're on the receiving end. The recipients of microaggressions always feel a sense of powerlessness and invisibility, while the aggressors are often unaware of the harm they’ve brought. The impact of microaggressions always negatively affects both mental and physical health of recipients and results in persistent health problems.

My goal of the thesis is to make the invisible visible. …

Fabrication Of Organic-Inorganic Hybrid Nanocomposite-Based Sensor For H2s Gas Detection, Fajr Ibrahim Musa Ali

Theses

Low power consumption, low limits of detection, and low cost are the compelling demands in the world of gas sensors development that motivate the search for new materials. Recently, gas sensors based on organic-inorganic nanocomposite materials have attracted much attention due to their high performance and low working temperatures in comparison with the commercial sensors for Hydrogen sulfide (H_₃S) gas. The development of H_₂S gas sensors is vital because H_₂S is one of the major air pollutants produced in large quantities in petroleum/natural gas drilling and refining. H_₂S gas is extremely toxic, …

The Use Of Electrical Resistance Tomography To Determine The Minimum Agitation Speed For Solids Suspension In Stirred Tank Reactors, Baran Teoman

Theses

Njs, the minimum agitation speed needed to just suspend all the solid particles in a solid-liquid mixture stirred in an agitated vessel, is a critical parameter to properly operate industrial tanks in a large number of industrial operations. As a result, a significant literature on Njs is available. The oldest and the most common method to measure Njs experimentally is that of Zwietering’s (Chem. Eng. Sci., 1958, 8, 244-253), where Njs can be visually obtained by determining when the solids stay at the bottom of the tank for no more than 1-2 seconds before being swept away. Although this has …

Blind Source Separation Using Dictionary Learning Over Time-Varying Channels, Anushreya Ghosh

Theses

Distributed sensors observe radio frequency (RF) sources over flat-fading channels. The activity pattern is sparse and intermittent in the sense that while the number of latent sources may be larger than the number of sensors, only a few of them may be active at any particular time instant. It is further assumed that the source activity is modeled by a Hidden Markov Model. In previous work, the Blind Source Separation (BSS) problem solved for stationary channels using Dictionary Learning (DL). This thesis studies the effect of time-varying channels on the performance of DL algorithms. The performance metric is the probability …

A Study Of Machine Learning And Deep Learning Models For Solving Medical Imaging Problems, Fadi G. Farhat

Theses

Application of machine learning and deep learning methods on medical imaging aims to create systems that can help in the diagnosis of disease and the automation of analyzing medical images in order to facilitate treatment planning. Deep learning methods do well in image recognition, but medical images present unique challenges. The lack of large amounts of data, the image size, and the high class-imbalance in most datasets, makes training a machine learning model to recognize a particular pattern that is typically present only in case images a formidable task.

Experiments are conducted to classify breast cancer images as healthy or …

Tomato Puree Convective Heat Transfer Simulation Using Boussinesq Approximation, Matteo Fabbri

Theses

With the advance of new technologies, the food industries are requiring systems that allow to produce the desired products with faster rates at cheaper costs. In this case, the study was initiated with the purpose to better understand what happens inside a package containing tomato puree when this is heated above 343 K in a tunnel pasteurizer. If the fluid must reach the thermal and microbiological condition of “pasteurization”, the system must guarantee that the temperature (around 343° Kelvin) is kept for a certain time allowing to pasteurize even the cooler package’s fluid-particle. The faster the system can heat the …

Deep Morphological Neural Networks, Yucong Shen

Theses

Mathematical morphology is a theory and technique applied to collect features like geometric and topological structures in digital images. Determining suitable morphological operations and structuring elements for a give purpose is a cumbersome and time-consuming task. In this paper, morphological neural networks are proposed to address this problem. Serving as a non-linear feature extracting layers in deep learning frameworks, the efficiency of the proposed morphological layer is confirmed analytically and empirically. With a known target, a single-filter morphological layer learns the structuring element correctly, and an adaptive layer can automatically select appropriate morphological operations. For high level applications, the proposed …

A Comparative Study Of Russian Trolls Using Several Machine Learning Models On Twitter Data, Kannan Neten Dharan Kannan Neten Dharan

Theses

Ever since Russian trolls have been brought into light, their interference in the 2016 US Presidential elections has been monitored and studied thoroughly. These Russian trolls have fake accounts registered on several major social media sites to influence public opinions. Our work involves trying to discover patterns in these tweets and classifying them by using different machine learning approaches such as Support Vector Machines, Word2vec and neural network models, and then creating a benchmark to compare all the different models. Two machine learning models are developed for this purpose. The first one is used to classify any given specific tweet …

Glass Transition Temperature Of Particles For Drug Delivery, Yiqing Yang

Theses

Drug delivery plays an important role in targeted therapies and nanoparticles which can be used as drug carriers and it’s a frequently researched topic. Poly(lactic-co-glycolic acid) (PLGA), a highly biocompatible polymer, has been used as a drug delivery vehicle in many studies. One of the challenges facing drug delivery particles is the problem of burst release which is when a large amount of the drug is suddenly released from the particle once it is placed in the body. This is generally undesirable as usually a slow and controlled release is preferred. The glass transition temperature has an effect on drug …

Calculating The Location Of The Center-Of-Gravity Using An Accelerometer Array, Kristin Angel

Theses

In this work, a method for determining a vehicle’s center-of-gravity using traditional commercially available sensors is developed. The method relies on using an accelerometer array along with rate gyro measurements for determining the linear acceleration of the vehicle along all directions at the center-of-gravity location. Once the acceleration at the center-of-gravity is formulated the location can be estimated by resolving measurements of acceleration not located at the center-of-gravity to the center-of-gravity location. Known kinematic equations are used to transform the accelerations at the instrument locations to the center-of-gravity location. An online parameter estimator is used to localize the center-of-gravity using …

Understanding The Relationship Between Sedimentation, Vegetation And Topography In The Tijuana River Estuary, San Diego, Ca., Darbi Berry

Theses

The aim of this study is to identify and characterize key geomorphic properties and relationships within the study site, the Tijuana River Estuary. This is a first step in contributing data to and assisting current and future restoration projects in employing a holistic management approach. The study identifies specific physical parameters, grain size and metal concentrations, within the estuary whose relationship to one another is not mutually exclusive and therefore should be addressed in tandem. This study also tests a remote sensing method for use as a tool for monitoring habitat changes in the estuary.

Monsters On The Move: Gravitational Recoil Of Supermassive Black Holes In Nearby Elliptical Galaxies, Yashashree Jadhav

Theses

It has long been assumed that Active Galactic Nuclei (AGN) reside at the centers of their host galaxies, but is this really true? A galaxy merger is expected to lead to the formation of a supermassive black hole (SMBH) binary, which can shrink through dynamical processes until it eventually coalesces through the emission of gravitational waves. Numerical relativity simulations show that, depending on the initial spin-orbit configuration of the binary, the merged SMBH receives a gravitational recoil kick that may reach several 1000 km s−1. The kick causes the merged SMBH to oscillate for up to ∼ 1 Gyr in …

Printable Thin-Film Sol-Gel Lead Zirconate Titanate (Pzt) Deposition Using Nanojet And Inkjet Printing Methods, Amanda R. Marotta

Theses

Lead zirconate titanate (PZT) sub-5µm thin-films deposited using NanoJet and inkjet printing techniques will be presented. PZT, a perovskite ferroelectric ceramic, possesses both electrical and mechanical properties making it well suited for sensor and actuator applications. Large-scale and additive manufacturing of PZT deposition is currently unobtainable. A novel PZT sol-gel, therefore, comprised of an alkoxide mixture, was adapted for printing. Polyethylene glycol (PEG, 200MW) was discovered to be a superior film forming aid to the PZT sol-gel composite. PEG was added to the PZT composite to prevent film cracking upon gelation and thermal sintering. A powder-based sample of the PZT …

Parameter Estimation Of A Cardiac Model Using The Local Ensemble Transform Kalman Filter, Nathan Holt

Theses

Cardiac arrhythmias are irregularities in the electrical activity in the heart; the electrical impulses in the heart become chaotic or disorganized, which can cause a possibly lethal problem to the contraction of the heart. In order to understand the dynamics of arrhythmias and to be able to predict and treat them, numerical models have been developed to capture the dynamics of the electrical impulses in the heart. In a clinical setting, optical mapping technologies — using cameras and voltage-sensitive dyes to capture the electrical impulses propagating across the heart — have been used to capture the dynamics of the electrical …

Some Statistical Properties Of Spectral Regression Estimators, Nawal Hassan

Theses

In this thesis we explore different Spectral Regression Estimators in order to solve the prob- lem in regression where we have multiple columns that are linearly dependent: We explore two scenarios

• Scenario 1: p << n where there exists at least two columns; xj and xk that are nearly linearly dependent which indicates co-linearity and X⊤X becomes near singular.

• Scenario 2: n << p since there are more predictors than observations so some columns must be a linear combination of another column which indicates linear dependence.

The scenarios give us an ill conditioned matrix of X⊤X (when solving the normal equa- tion) due to collinearity issues and the matrix becomes singular and makes the least squares estimate unstable and impossible to compute. In the paper, we explore different methods (variable selection, regularization, compression and dimensionality reduction) that solves the above issue. For variable selection techniques, we use …

Predict Network, Application Performance Using Machine Learning And Predictive Analytics, Mohamed Elmasry

Theses

In this thesis, a study is performed to find the effect of applications on resource consumption in computer networks and how to make use of available technologies such as predictive analytics, machine learning and business intelligence to predict if an application can degrade the network performance or consume computer system resources. In recent years, having a healthy computer system and the network is essential for continuity of business. The study focusses on analyzing the performance metrics collected from real networks using scripts and available programs created specifically for monitoring applications and network in real-time.

This work has significant importance because …

Aerospace Fuel Flow Metering Check Valve Model, Simulation, And Validation, Trevor M. Crandell

Theses

The fuel atomizer of a gas turbine engine is a critical component of study, design, and manufacture for the gas turbine industry. Modern engines rely on consistent precise operation of fuel nozzles to achieve today’s progressive emission standards and to keep engines operating longer and to keep them overall more competitive. The previous research into this field is extensive but has left a gap where relatively computationally simple methods can be used to benefit companies that build aerospace fuel nozzles. Through simulation and experimentation, the goal of this research was to create a method of modeling aerospace fuel nozzle flow …

Effects Of Grazer Exclusion On Carbon Cycling In Created Freshwater Wetlands, Delanie Spangler

Theses

Wetland ecosystems play a significant role in the global carbon cycle, and yet are increasingly threatened by human development, climate change, and shifts in populations of large grazers. The loss of intact wetland systems heightens the need for effective wetland creation and restoration. However, wetland ecosystems are highly complex, complicating efforts to replace the functionality and delivery of ecosystem services associated with natural wetlands. Increasing waterfowl populations pose a threat to the development and persistence of created wetlands, largely through intensive grazing that can shift vegetation community structure or altogether limit desired plant establishment. This study capitalizes on a long-term …

Controllability Of Cardiac Alternans, Mark O. Ampofo

Theses

An arrhythmia is a disorder in the heart that occurs due to irregular or abnormal heartbeats. There are many types of arrhythmias, some of which are harmless, but some, including ventricular tachycardia and fibrillation, can be life-threatening. Certain arrhythmias are preceded by electrical alternans, which is a state characterized by beat-to-beat alternation in cellular action potential duration. Cardiac alternans may arise from instabilities in either voltage or intracellular calcium cycling. Although a number of techniques have been proposed to suppress alternans, most have focused on appropriately adding a new ionic current or adjusting the timing of pacing stimuli based on …

Advantages And Challenges Of Online Project Based Learning, Peter Alex Kow Amissah

Theses

The purpose of this research is to outline the advantages and challenges of online project-based learning. Becoming knowledgeable about online project-based learning (PBL) is crucial at a time when there is an increased demand for education. The discussion presented here will assist faculty in the teaching of online PBL. The researcher conducted a comprehensive review of the literature and developed an open-ended interview schedule based upon his findings, which was used to interview experts in the field. The experts’ views confirmed the advantages and challenges found in the literature and brought up other factors that were not discovered in the …