Physical Sciences and Mathematics Commons^™

Detection And Characterization Of Extrasolar Planets Through Planet-Disk Dynamical Interactions, Maryam Tabeshian

Electronic Thesis and Dissertation Repository

Structures observed in circumstellar disks may be caused by gravitational interaction with planetary or stellar companions. These perturbed disks are often signposts of planet birth in exoplanetary systems, and offer insights into the properties of both the disk and the perturbing planets. Therefore, structures observed in these disks provide a powerful tool for detecting and studying extrasolar planetary systems. In this work, we examine the link between disk structures and nearby/embedded planets using numerical simulations of both hypothetical and observed disk systems.

We demonstrate that gaps can be opened in dynamically cold debris disks at the mean-motion resonances (MMRs) of …

Investigating Citation Linkage Between Research Articles, Kokou Hospice Houngbo

Electronic Thesis and Dissertation Repository

In recent years, there has been a dramatic increase in scientific publications across the globe. To help navigate this overabundance of information, methods have been devised to find papers with related content, but they are lacking in the ability to provide specific information that a researcher may need without having to read hundreds of linked papers. The search and browsing capabilities of online domain specific scientific repositories are limited to finding a paper citing other papers, but do not point to the specific text that is being cited. Providing this capability to the research community will be beneficial in terms …

Patch-Based Denoising Algorithms For Single And Multi-View Images, Monagi H. Alkinani

Electronic Thesis and Dissertation Repository

In general, all single and multi-view digital images are captured using sensors, where they are often contaminated with noise, which is an undesired random signal. Such noise can also be produced during transmission or by lossy image compression. Reducing the noise and enhancing those images is among the fundamental digital image processing tasks. Improving the performance of image denoising methods, would greatly contribute to single or multi-view image processing techniques, e.g. segmentation, computing disparity maps, etc. Patch-based denoising methods have recently emerged as the state-of-the-art denoising approaches for various additive noise levels. This thesis proposes two patch-based denoising methods for …

Improving Deep Learning Image Recognition Performance Using Region Of Interest Localization Networks, Abdulwahab Kabani

Electronic Thesis and Dissertation Repository

Deep Learning has been gaining momentum and achieving the state-of-the-art results on many visual recognition problems. The roots of this field can be traced back to the 1940s of the 20th century. The field has recently started delivering some interesting results on many image understanding problems. This is mainly due to the availability of powerful hardware that can accelerate the training process. In addition, the growth of the Internet and imaging devices such as mobile phones and cameras has contributed to the increase in the amount of data that can be used to train neural networks. All of these factors …

Visual Transfer Learning In The Absence Of The Source Data, Shuang Ao

Electronic Thesis and Dissertation Repository

Image recognition has become one of the most popular topics in machine learning. With the development of Deep Convolutional Neural Networks (CNN) and the help of the large scale labeled image database such as ImageNet, modern image recognition models can achieve competitive performance compared to human annotation in some general image recognition tasks. Many IT companies have adopted it to improve their visual related tasks. However, training these large scale deep neural networks requires thousands or even millions of labeled images, which is an obstacle when applying it to a specific visual task with limited training data. Visual transfer learning …

On Vector-Valued Automorphic Forms On Bounded Symmetric Domains, Nadia Alluhaibi

Electronic Thesis and Dissertation Repository

The objective of the study is to investigate the behaviour of the inner products of vector-valued Poincare series, for large weight, associated to submanifolds of a quotient of the complex unit ball and how vector-valued automorphic forms could be constructed via Poincare series. In addition, it provides a proof of that vector-valued Poincare series on an irreducible bounded symmetric domain span the space of vector-valued automorphic forms.

Multi-View Ontology Explorer (Moe): Interactive Visual Exploration Of Ontologies, Zhao Lin

Electronic Thesis and Dissertation Repository

An ontology is an explicit specification of a conceptualization. This specification consists of a common vocabulary and information structure of a domain. Ontologies have applications in many fields to semantically link information in a standardized manner. In these fields, it is often crucial for both expert and non-expert users to quickly grasp the contents of an ontology; and to achieve this, many ontology tools implement visualization components. There are many past works on ontology visualization, and most of these tools are adapted from tree and graph based visualization techniques (e.g. treemaps, node-link graphs, and 3D interfaces). However, due to the …

Developments In Pet-Mri For Radiotherapy Planning Applications, John Christian Patrick

Electronic Thesis and Dissertation Repository

The hybridization of magnetic resonance imaging (MRI) and positron emission tomography (PET) provides the benefit of soft-tissue contrast and specific molecular information in a simultaneous acquisition. The applications of PET-MRI in radiotherapy are only starting to be realised. However, quantitative accuracy of PET relies on accurate attenuation correction (AC) of, not only the patient anatomy but also MRI hardware and current methods, which are prone to artefacts caused by dense materials. Quantitative accuracy of PET also relies on full characterization of patient motion during the scan. The simultaneity of PET-MRI makes it especially suited for motion correction. However, quality assurance …

Metafork: A Compilation Framework For Concurrency Models Targeting Hardware Accelerators, Xiaohui Chen

Electronic Thesis and Dissertation Repository

Parallel programming is gaining ground in various domains due to the tremendous computational power that it brings; however, it also requires a substantial code crafting effort to achieve performance improvement. Unfortunately, in most cases, performance tuning has to be accomplished manually by programmers. We argue that automated tuning is necessary due to the combination of the following factors. First, code optimization is machine-dependent. That is, optimization preferred on one machine may be not suitable for another machine. Second, as the possible optimization search space increases, manually finding an optimized configuration is hard. Therefore, developing new compiler techniques for optimizing applications …

Experimental Studies Of Electrical Resistivity Behavior Of Cu, Zn And Co Along Their Melting Boundaries: Implications For Heat Flux At Earth’S Inner Core Boundary, Innocent Chinweikpe Ezenwa

Electronic Thesis and Dissertation Repository

Abstract

The electrical resistivity of high purity Cu, Zn and Co has been measured at pressures (P) up to 5GPa and at temperatures (T) in the liquid phase. The electrical resistivity of solid state Nb was also measured up to 5GPa and ~1900K. All measurements were made in a large volume cubic anvil press. Using two thermocouples placed at opposite ends of the sample wire, serving as temperature probes as well as resistance leads, a four-wire technique resistivity measurement was employed along with a polarity switch. Post-experiment compositional analyses were carried out on an electron microprobe.

The expected resistivity decrease …

Detection And Recognition Of Traffic Signs Inside The Attentional Visual Field Of Drivers, Seyedjamal Zabihi

Electronic Thesis and Dissertation Repository

Traffic sign detection and recognition systems are essential components of Advanced Driver Assistance Systems and self-driving vehicles. In this contribution we present a vision-based framework which detects and recognizes traffic signs inside the attentional visual field of drivers. This technique takes advantage of the driver's 3D absolute gaze point obtained through the combined use of a front-view stereo imaging system and a non-contact 3D gaze tracker. We used a linear Support Vector Machine as a classifier and a Histogram of Oriented Gradient as features for detection. Recognition is performed by using Scale Invariant Feature Transforms and color information. Our technique …

Developing Predictive Models Of Driver Behaviour For The Design Of Advanced Driving Assistance Systems, Seyed Mohsen Zabihi

Electronic Thesis and Dissertation Repository

World-wide injuries in vehicle accidents have been on the rise in recent

years, mainly due to driver error. The main objective of this research is to

develop a predictive system for driving maneuvers by analyzing the cognitive

behavior (cephalo-ocular) and the driving behavior of the driver (how the vehicle

is being driven). Advanced Driving Assistance Systems (ADAS) include

different driving functions, such as vehicle parking, lane departure warning,

blind spot detection, and so on. While much research has been performed on

developing automated co-driver systems, little attention has been paid to the

fact that the driver plays an important role …

Using Machine Learning To Predict Chemotherapy Response In Cell Lines And Patients Based On Genetic Expression, Dimo Angelov

Electronic Thesis and Dissertation Repository

The goal of this thesis was to examine different machine learning techniques for predicting chemotherapy response in cell lines and patients based on genetic expression. After trying regression, multi-class classification techniques and binary classification it was concluded that binary classification was the best method for training models due to the limited size of available cell line data. We found support vector machine classifiers trained on cell line data were easier to use and produced better results compared to neural networks. Sequential backward feature selection was able to select genes for the models that produced good results, however the greedy algorithm …

Electrochemical And Modelling Studies On Simulated Spent Nuclear Fuel Corrosion Under Permanent Waste Disposal Conditions, Nazhen Liu

Electronic Thesis and Dissertation Repository

The safety assessment models for the deep geological disposal of spent nuclear fuel require a fundamental understanding of the corrosion of spent fuel in a failed waste container. The overall research goal of this project is to investigate the corrosion of simulated spent fuel under permanent disposal conditions, using both model simulations and experimental investigations. A model for fuel corrosion has been expanded to determine the relative importance of radiolytic hydrogen and hydrogen from corrosion of the steel vessel in suppressing fuel corrosion. It was shown that, for CANDU (CANada Deuterium Uranium) fuel with moderate in-reactor burnup, only micromolar concentrations …

Confidence Interval Estimation Of Cumulative Incidence For Clustered Competing Risks, Atul Sivaswamy

Electronic Thesis and Dissertation Repository

In a cluster randomized trial studying a primary outcome patients are sometimes exposed to competing events. These are risks that alter the probability of the primary outcome occurring. Traditional methods of estimating the cumulative incidence for an outcome and its associated confidence interval under competing risks do not account for the effect of clustering. This may cause incorrect estimation of confidence intervals because outcomes among patients from the same center are correlated. This thesis compared six nonparametric methods of confidence interval construction for cumulative incidence, four of which account for clustering effect, under competing risks via simulation study. Over the …

Cu-Pd Mineralization And Exploration Geochemistry Of The Eastern Gabbro, Coldwell Alkaline Complex, On, Canada, Yonghua Cao

Electronic Thesis and Dissertation Repository

The Eastern Gabbro forms the northern and eastern margin of the Coldwell Alkaline Complex. It contains three magma series: the barren meta-basalt, the Layered Series, and the Marathon Series which hosts all known PGE mineralization. The Marathon Series can be distinguished from other Series using the combination of portable X-ray fluorescence (pXRF) and benchtop scanning electron microscope (bSEM). Whole-rock Ba, Mg# (molar Mg/(Mg+Fe)*100), Zr and V/Ti values acquired from pXRF, and Mg#s of olivine and clinopyroxene, and anorthite content (molar Ca/(Ca+Na)*100) of plagioclase acquired from bSEM-EDS are key parameters. The Layered Series generally contains higher Ba and lower V/Ti than …

Synthesis Of Manganese(Ii) Containing Metal Chalcogen Cluster Complexes From Metal Trimethylsilylthiolate Precursors, Kyle Nw Rozic

Electronic Thesis and Dissertation Repository

The manganese(II)‐palladium(II)‐sulfide complex [MnCl₂(μ₃‐S)₂Pd₂(dppp)₂] 2 has been isolated from the reaction of [(dppp)PdCl₂] with [Li(N,N’‐tmeda)]₂[Mn(SSiMe₃)₄] 1 in a 2:1 ratio under mild conditions. The trimethylsilyl thiolate complex [(dppp)Pd(SSiMe₃)₂] 3 has been synthesized from the reaction of [(dppp)PdCl₂] with Li[SSiMe₃] as well as the reaction of [(dppp)Pd(OAc)₂] with Li[SSiMe₃] under mild conditions. The newly synthesized complex [(dppp)Pd(SSiMe₃)₂] 3 was used in reaction with the manganese(II) salt [(CH …

Integration Of Orbital-Dependent Exchange-Correlation Potentials, Hanqing Zhao

Electronic Thesis and Dissertation Repository

In density-functional theory, one can approximate either the exchange-correlation energy functional or the corresponding Kohn--Sham effective potential, which is then converted into an energy functional by functional integration. A directly approximated potential may depend on the electron density explicitly or implicitly through Kohn--Sham orbitals. A potential that depends on the electron density explicitly can be converted into an energy functional by evaluating the Leeuwen--Baerends line integral along some path of electron densities. We extend this technique to orbital-dependent potentials by integrating them along the path of scaled orbitals. Using this method, we assign energy expressions to the Slater, Becke--Johnson and …

Design Of Radio-Frequency Arrays For Ultra-High Field Mri, Ian R O Connell

Electronic Thesis and Dissertation Repository

Magnetic Resonance Imaging (MRI) is an indispensable, non-invasive diagnostic tool for the assessment of disease and function. As an investigational device, MRI has found routine use in both basic science research and medicine for both human and non-human subjects.

Due to the potential increase in spatial resolution, signal-to-noise ratio (SNR), and the ability to exploit novel tissue contrasts, the main magnetic field strength of human MRI scanners has steadily increased since inception. Beginning in the early 1980’s, 0.15 T human MRI scanners have steadily risen in main magnetic field strength with ultra-high field (UHF) 8 T MRI systems deemed to …

Full-Waveform Inversion With Scaled-Sobolev Preconditioning Applied To Vibroseis Field Data, Benjamin Paul Consolvo

Electronic Thesis and Dissertation Repository

I present an application of a high-resolution subsurface imaging technique known as “full-waveform inversion” (FWI) to a vibroseis seismic dataset from eastern Ohio, USA. The data were collected over a crooked line with rough topography, 3.5 km maximum offsets, and no significant frequency content below 12 Hz. These parameters present challenges to obtaining quality images from FWI. The use of a preconditioner–the ‘scaled-Sobolev preconditioner’ (SSP - Zuberi and Pratt, 2017)–on the gradient of the misfit functional was key to obtaining low wavenumbers without discarding high wavenumbers. The results represent the first successful application of FWI with the SSP to a …

Fast Fourier Transforms Over Prime Fields Of Large Characteristic And Their Implementation On Graphics Processing Units, Davood Mohajerani

Electronic Thesis and Dissertation Repository

Prime field arithmetic plays a central role in computer algebra and supports computation in Galois fields which are essential to coding theory and cryptography algorithms. The prime fields that are used in computer algebra systems, in particular in the implementation of modular methods, are often of small characteristic, that is, based on prime numbers that fit on a machine word. Increasing precision beyond the machine word size can be done via the Chinese Remaindering Theorem or Hensel Lemma. In this thesis, we consider prime fields of large characteristic, typically fitting on n machine words, where n is a power of …

Analysis Of 3d Cone-Beam Ct Image Reconstruction Performance On A Fpga, Devin Held

Electronic Thesis and Dissertation Repository

Efficient and accurate tomographic image reconstruction has been an intensive topic of research due to the increasing everyday usage in areas such as radiology, biology, and materials science. Computed tomography (CT) scans are used to analyze internal structures through capture of x-ray images. Cone-beam CT scans project a cone-shaped x-ray to capture 2D image data from a single focal point, rotating around the object. CT scans are prone to multiple artifacts, including motion blur, streaks, and pixel irregularities, therefore must be run through image reconstruction software to reduce visual artifacts. The most common algorithm used is the Feldkamp, Davis, and …

Nanoscale Thermal And Electronic Properties Of Thin Films Of Graphene And Organic Polyradicals, Sabastine Chukwuemeka Ezugwu

Electronic Thesis and Dissertation Repository

Ultrathin film materials have attracted significant attention in light of their potential applications in very large scale integrated electronics and data storage. For instance, the amount of data that can be addressed and stored in a memory device scales inversely with the thinness of the active layer of these components. In our thesis, we have developed a suite of scanning-probe and nano-optical techniques focused on understanding the electronic surface properties and the thermal conductivity of ultrathin materials. We discuss a few specific examples in which we applied these techniques towards improved performance of thin films of graphene and organic polyradicals …

Synthesis Of Metal-Containing Phosphines And Their Use In Coordination, Polymer, And Materials Chemistry, Amir Rabiee Kenaree

Electronic Thesis and Dissertation Repository

This thesis describes the investigation of a novel strategy for the synthesis of metal-containing small molecules, polymers, and nanomaterials. In this context, a new family of air-stable, homo- and heterometallic primary, secondary, and tertiary phosphines were prepared via the radical-initiated hydrophosphination reaction of PH₃ with vinylferrocene and/or vinylruthenocene. The full characterization of the phosphines confirmed their targeted structures and proved that the properties of the starting metallocenes are reflected in those of the resulting phosphines.

To study the coordination behavior of this family of phosphines, primary, secondary, and tertiary ethylferrocene phosphines were reacted with Group 6 metal carbonyl adducts …

Regulatory Compliance-Oriented Impediments And Associated Effort Estimation Metrics In Requirements Engineering For Contractual Systems Engineering Projects, Md Rashed I. Nekvi

Electronic Thesis and Dissertation Repository

Large-scale contractual systems engineering projects often need to comply with a myriad of government regulations and standards as part of contractual fulfillment. A key activity in the requirements engineering (RE) process for such a project is to elicit appropriate requirements from the regulations and standards that apply to the target system. However, there are impediments in achieving compliance due to such factors as: the voluminous contract and its high-level specifications, large number of regulatory documents, and multiple domains of the system. Little empirical research has been conducted on developing a shared understanding of the compliance-oriented complexities involved in such projects, …

Creating Functional Materials With Phosphorus, Tyler John Cuthbert

Electronic Thesis and Dissertation Repository

Understanding the relationship between small molecules or polymers and how they affect the properties of materials they compose is the basis of materials science. Using unique and versatile components can impart useful and interesting properties to materials. Here, we aimed to extend this understanding to phosphorus, and the known properties it possesses. This included the production of photopolymerizable coatings containing phosphonium molecules and polymers for antifouling and antibacterial applications. The synthesis and characterization of these phosphonium components was completed and materials were produced utilizing UV curing technology. Addition of these components produced coatings that could resist bacteria attachment and efficiently …

X-Ray Absorption And Emission Studies Of Anodic Titania Nanostructures, Jun Li

Electronic Thesis and Dissertation Repository

One-dimensional (1D) TiO₂ nanomaterials with ordered structure have been extensively applied in various fields, such as photocatalysts, solar cells, supercapacitors and rechargeable batteries, due to the unique structural and functional properties compared to the disordered nanoparticulate forms. Nevertheless, intrinsic disadvantages of TiO₂, such as its large band gap (~3 eV), fast recombination rate of photoexcited electron–hole pairs and insufficient ionic conductivity, severely limit the development of 1D TiO₂ nanomaterials for practical applications. To address the above issues, the scope of this thesis focus on the fundamental understandings of the electronic structure of highly ordered TiO_{2 …}

Synthesis Of Metal-Containing Polymers And Stable Organic Radical-Containing Polymers And Their Use As Advanced Functional Materials, Joseph A. Paquette

Electronic Thesis and Dissertation Repository

The work presented in this thesis details the synthesis and characterization of two different families of multifunctional polymers. The first family involved the incorporation of stable 6-oxoverdazyl radicals into polymer scaffolds. This was originally achieved by the polymerization of the radical precursors, phenyl- and isopropyl-6-oxotetrazanes, followed by post-polymerization oxidation to afford the phenyl- and isopropyl-6-oxoverdazyl polymers. A second methodology involved the direct polymerization of isopropyl-6-oxoverdazyl radicals using ring-opening metathesis polymerization (ROMP) to afford polymers with controlled molecular weights and narrow molecular weight distributions. The polymers were characterized by the close comparison of the physical and spectroscopic properties …

Static Magnetic Field Interactions Of Medical Devices In The Mri Environment, Spencer Baird Parent

Electronic Thesis and Dissertation Repository

Background: The current procedures and guidelines for testing medical devices require that conservative testing be carried-out using the “worst-case” device or device configuration for each interaction (force, torque, heating, et cetera) of importance, and the results of those tests be used to inform regulatory labeling for that device. One of the most difficult elements of carrying out the above procedure is the determination of what represents a “worst-case” device or device configuration. A simulation “pipeline” would enable a systematic procedure for identification of the worst-case device or device configuration for magnetic force from an otherwise impossibly large set of options. …

Properties Of High Nitrogen Content Carbon Nitride Thin Films Prepared By A Radio Frequency Magnetron Sputtering Deposition Technique, David Pipher

Electronic Thesis and Dissertation Repository

The properties of carbon nitride (CNx) films deposited onto various substrates using a radiofrequency magnetron sputtering technique were studied as a function of deposition parameters, especially magnetron power, gas pressure and nitrogen content in the plasma. Indium tin oxide (ITO) coated glass and fluorine tin oxide (FTO) coated glass as well as metal substrates (silver and tungsten) were used. Scanning electron microscopy (SEM) was used to study the surface morphology of the prepared CNx films. Energy-dispersive X-ray spectroscopy (EDX) as well as survey X-ray photoelectron spectroscopy (XPS) spectra were used to perform the elemental analysis of the CNx films.

Ultraviolet-visible …