Physical Sciences and Mathematics Commons^™

Predicting Software Fault Proneness Using Machine Learning, Sanjay Ghanathey

Electronic Thesis and Dissertation Repository

Context: Continuous Integration (CI) is a DevOps technique which is widely used in practice. Studies show that its adoption rates will increase even further. At the same time, it is argued that maintaining product quality requires extensive and time consuming, testing and code reviews. In this context, if not done properly, shorter sprint cycles and agile practices entail higher risk for the quality of the product. It has been reported in literature [68], that lack of proper test strategies, poor test quality and team dependencies are some of the major challenges encountered in continuous integration and deployment.

Objective: The objective …

Partitioning And Offloading For Iot And Video Streaming Applications That Utilize Computing Resources At The Network Edge, Navid Bayat

Electronic Thesis and Dissertation Repository

The Internet of Things (IoT) is a concept in which physical objects embedded with sensors, actuators, and network connectivity can communicate and react to their surroundings. IoT applications connect physical objects for the purpose of decision making by sensing and analysing generated data from the embedded sensors in physical objects. IoT applications are growing rapidly as sensors become less expensive. Sensors generate large amounts of data that may meaningless unless the data is used to derive knowledge with in a certain period of time. Stream processing paradigm is used by IoT to provide requirements of IoT applications. In a stream …

Advancements In Fractal Plasmonics: Structures, Optical Properties, And Applications., Gregory Q Wallace, Francois Lagugne-Labarthet

Chemistry Publications

The structural characteristics of plasmonic nanostructures directly influence their plasmonic properties, and therefore, their potential role in applications ranging from sensing and catalysis to light- and energy-harvesting. For a structure to be compatible with a selected application, it is critical to accurately tune the plasmonic properties over a specific spectral range. Fabricating structures that meet these stringent requirements remains a significant challenge as plasmon resonances are generally narrow with respect to the considered selected spectral range. Adapted from their well-established role in GHz applications, plasmonic fractal structures have emerged as architectures of interest due to their ability to support multiple …

Photo-Isomerizable Complementary Hydrogen Bond Arrays, Jeffrey S. Pleizier

Electronic Thesis and Dissertation Repository

The use of light as an external stimulus provides a non-invasive technique to induce large changes in physical and chemical properties of a substrate. The incorporation of a photochromic subunit into supramolecular polymeric systems therefore adds a potential "smart" quality for polymer manipulation. The azo moiety (-N=N-) is one of the most popular photochromic units as the trans to cis isomerization results in a large degree of spatial rearrangement. This present thesis exploits the azo group by its incorporation into complementary hydrogen bonded complexes. Hydrogen bonding acceptor groups attached to the periphery of the central azo photoswitch provided strong complexation …

Validating And Highlighting The Advantages Of The Optimal Estimation Method For Rayleigh Lidar Middle Atmospheric Temperature Retrievals, Ali Jalali

Electronic Thesis and Dissertation Repository

An improved understanding of temperature variations in Earth’s middle atmosphere is important for the improvement of our understanding of climate and weather on the surface. The optimal estimation method (OEM) is an inversion modeling approach, which uses regularized nonlinear regression to retrieve, in this case, the temperature of Earth’s middle atmosphere using Rayleigh-scatter lidar measurements. The OEM regularization term is the a priori knowledge of the atmospheric temperature profile. In this thesis I use lidar temperatures in the altitude range 30–110km to construct a temperature climatology using over 500 nights of measurements obtained by the Purple Crow Lidar in London, …

Secured Data Masking Framework And Technique For Preserving Privacy In A Business Intelligence Analytics Platform, Osama Ali

Electronic Thesis and Dissertation Repository

The main concept behind business intelligence (BI) is how to use integrated data across different business systems within an enterprise to make strategic decisions. It is difficult to map internal and external BI’s users to subsets of the enterprise’s data warehouse (DW), resulting that protecting the privacy of this data while maintaining its utility is a challenging task. Today, such DW systems constitute one of the most serious privacy breach threats that an enterprise might face when many internal users of different security levels have access to BI components. This thesis proposes a data masking framework (iMaskU: Identify, Map, Apply, …

Development Of Exploratory Data Analysis Methods For Chemical, Spatial And Temporal Analysis Of Surface Water Quality Data: The Ontario Provincial Water Quality Monitoring Network, Shuyang Wang

Electronic Thesis and Dissertation Repository

Surface water quality (SWQ) databases have been widely compiled to provide information characterizing environmental conditions. But SWQ databases appear to be under-utilized, given the large investment in their creation. One reason is that database spatial, temporal, and compositional dimension vary through time, reflecting changing priorities through time and contrasts between different agencies, making coherent analysis challenging. This thesis explores the Ontario Provincial Water Quality Monitoring Network (PWQMN) to derive higher order hydrochemical properties, to render SWQ data in “network space” permitting catchment-wide visualization, and in undertaking temporal trend analysis.

Rivers play a critical role in the terrestrial carbon cycle, but …

Investigation Of Flow Disturbances And Multi-Directional Wall Shear Stress In The Stenosed Carotid Artery Bifurcation Using Particle Image Velocimetry, Amanda L. Dicarlo

Electronic Thesis and Dissertation Repository

Hemodynamics and shear forces are associated with pathological changes in the vascular wall and its function, resulting in the focal development of atherosclerosis. Flow complexities that develop in the presence of established plaques create environments favourable to thrombosis formation and potentially plaque rupture leading to stroke. The carotid artery bifurcation is a common site of atherosclerosis development. Recently, the multi-directional nature of shear stress acting on the endothelial layer has been highlighted as a risk factor for atherogenesis, emphasizing the need for accurate measurements of shear stress magnitude as well direction. In the absence of comprehensive patient specific datasets numerical …

Corrosion Dynamics Of Carbon Steel In Used Fuel Container Environments, Dan Guo

Electronic Thesis and Dissertation Repository

The current Canadian used nuclear fuel container (UFC) design uses a pressure‑grade carbon steel (CS) vessel with its outer surface coated with a thin layer of copper. One concern regarding the structural integrity of the UFC design is the potential internal corrosion of the CS vessel. Moisture trapped inside a UFC could condense within the gap between the hemispherical head and the cylindrical body of the vessel. The internal UFC environment will be exposed to a continuous flux of ionizing radiation arising from the decay of radionuclides trapped in the used UO₂ fuel matrix.

This thesis research project investigates …

Complexity Results For Fourier-Motzkin Elimination, Delaram Talaashrafi

Electronic Thesis and Dissertation Repository

In this thesis, we propose a new method for removing all the redundant inequalities generated by Fourier-Motzkin elimination. This method is based on Kohler’s work and an improved version of Balas’ work. Moreover, this method only uses arithmetic operations on matrices. Algebraic complexity estimates and experimental results show that our method outperforms alternative approaches based on linear programming.

Multiwavelength, Machine Learning, And Parallax Studies Of X-Ray Binaries In Three Local Group Galaxies, Robin Arnason

Electronic Thesis and Dissertation Repository

X-ray binary stars are rare systems consisting of a black hole or neutron star and a main-sequence companion star. They are useful probes of galaxy properties and interesting laboratories for extreme physical conditions. In this thesis, I investigated the X-ray binary population of three galaxies in the Local Group.

The Sculptor Dwarf Spheroidal Galaxy offers the chance to study a primordial low-mass X-ray binary (LMXB) population in an isolated, low-metallicity environment. Combining X-ray, optical, and infrared observations, I have studied nine previously-identified and discovered four additional LMXB candidates in this galaxy. Of these candidates, all but one are either background …

Understanding New Trends On Gold Mineralization At The Yellowknife City Gold Project, Northwest Territories, Using Synchrotron X-Ray Spectroscopy, Ramjay Jude L. Botor

Electronic Thesis and Dissertation Repository

The Yellowknife City Gold Project (YCGP) currently encompasses 780 sq. km of contiguous land north, south and east of the city of Yellowknife. The project lies in the prolific Archean north-south trending Yellowknife Greenstone Belt, a suite of mafic and felsic volcanics and greywacke turbidites overlying a gneissic basement. Exploration and drilling efforts have been focused along 70 km of strike length on the southern and northern extensions of the mineralized shear zones and quartz veins associated with the past-producing high-grade Con (6.1 Moz @ 16.1 g/t Au) and Giant (8.1 Moz @ 16.0 g/t Au) gold mines.

Synchrotron X-ray …

Electrical Resistivity Of Nickel, Iron And Iron-Silicon Alloy Melts At High Pressure With Implications For The Thermal Conductivity Of The Earth’S Core, Reynold E. Silber

Electronic Thesis and Dissertation Repository

The Earth’s liquid outer core (OC) is composed of Fe alloyed with up to 10% Ni and a small fraction of light elements. However, the effect of light elements such as Si on the transport properties of liquid Fe-alloy in Earth’s OC is not clear. Thermal conductivity (κ) and related electrical resistivity (ρ) are the least constrained parameters in OC. Therefore, the characterization of transport properties of Ni, Fe and Fe-Si at high pressure has important geophysical implications for the Earth’s core. The ρ of solid and liquid Ni, Fe and Fe 4%Si was measured at …

Properties Of Si Quantum Dots, Carolyn C. F Cadogan

Electronic Thesis and Dissertation Repository

The fundamental properties of matter in confined particles change dramatically due to quantum effects. In this work, we have explored the optical properties of silicon quantum dots (Si-QDs) embedded in Si₃N₄; and the role of crystallinity on the optical properties and formation of Si-QDs in Al₂O₃. This work examined the role of (1) annealing temperature and the composition of the film, (2) Al doping of the host Si₃N₄ film, (3) doping Si-QDs and (4) Al and P passivation of Si-QDs on the PL intensity of Si-QDs embedded in Si …

Morphologic Mapping Of Lunar Impact Basins, Zachary R. Morse

Electronic Thesis and Dissertation Repository

Modern high-resolution remote sensing datasets for the Moon provide a detailed view of the lunar surface and its features. This thesis uses visible, compositional, and topographic data to create the most detailed geomorphological maps to date of portions of three lunar impact structures: Orientale Basin, Tsiolkovsky Crater, and Schrödinger Basin, which are three of the best-preserved impact structures on the lunar farside.

This thesis discusses the mapping and analysis of seven distinct ejecta facies around Orientale, nine distinct facies in and around Tsiolkovsky, and twelve units of surface materials in the central Schrödinger Basin region. This analysis utilized 100 m/pixel …

Causes And Consequences Of Soil Carbon Mobilization And Lake Brownification In Northern Forested Landscapes, Óscar Esbrí Senar

Electronic Thesis and Dissertation Repository

Global changes are fundamentally changing terrestrial and aquatic ecosystems. Some of the highest rates of global change are in the north, where they are leading to the faster destabilization of forest soil carbon and its mobilization as dissolved organic matter and causing the brownification of lakes. This thesis investigated the causes of soil carbon destabilization and consequences of the mobilized soil carbon to lake food webs. The first finding was that global change increased carbon export from catchments. Increased temperatures and changes in hydrologic connectivity interacted with catchment topography to modulate the timing, magnitude, and fate of soil carbon export. …

Robust Earthquake Site Classification Assessment At Ontario Bridge Sites., Alex Bilson Darko

Electronic Thesis and Dissertation Repository

Canadian seismic design guidelines classify subsurface ground conditions based on the average shear-wave velocity (V_S) of the upper 30 meters (V_S30). We seek to optimize a robust earthquake site classification procedure for Ontario bridge sites, assessed primarily from blind comparison of non-invasive V_S depth profiling techniques. Non-invasive seismic testing is performed at 10 bridge sites in southern Ontario co-located with invasive penetration and/or borehole V_S measurements. Non-invasive surface wave dispersion and site amplification functions are jointly inverted to retrieve V_S profiles at each site. A general correlation between corrected V_S and cone …

Near-Infrared Photoluminescence And Electrochemiluminescence From An Exceptionally Simple Boron Difluoride Formazanate Dye, Ryan R. Maar, Ruizhong Zhang, David G. Stephens, Zhifeng Ding, Joe Gilroy

Chemistry Publications

Electrochemiluminescence involves the generation of light via electrochemical reactions and has recently shown utility for single-cell imaging. To further develop this novel imaging platform, it is necessary to produce readily available dyes that photoluminesce and electrochemiluminesce in the near-infrared region to limit absorption by biological tissue. To address this need, we prepared a boron difluoride formazanate dye that exhibits near-infrared photoluminescence and electrochemiluminescence in two straightforward synthetic steps. Examination of its solid-state structure suggests that the N-aryl substituents have significant quinoidal character, which narrows the S₁-S₀ energy gap and leads to near-infrared absorption and photoluminescence. Electrochemical …

Empirical Characterization Of Induced Seismicity In Alberta And Oklahoma, Mark Novakovic

Electronic Thesis and Dissertation Repository

This thesis characterizes ground motions from induced seismic events in Alberta and Oklahoma, following an overall methodology that uses ground-motion recordings to calibrate the parameters of a seismological model. This body of work is carried out in three related studies.

In the first study, we perform a preliminary evaluation of ground motions in Alberta using thousands of observations of natural, induced and blast events of magnitude 1 to 4, recorded on a newly-deployed regional seismograph array. We evaluate the applicability of a moment magnitude (M) estimation algorithm for the events and compare the observed ground motions with expectations …

Anisotropic Kernel Smoothing For Change-Point Data With An Analysis Of Fire Spread Rate Variability, John Ronald James Thompson

Electronic Thesis and Dissertation Repository

Wildland fires are natural disturbances that enable the renewal of forests. However, these fires also place public safety and property at risk. Understanding forest fire spread in any region of Canada is critical to promoting forest health, and protecting human life and infrastructure. In 2014, Ontario updated its Wildland Fire Management Strategy, moving away from ``zone-based" decision making to ``appropriate response" decision making. This new strategy calls for an assessment of the risks and benefits of every wildland fire reported in the province. My research places the emphasis on the knowledge and understanding of fire spread rates and their variabilities. …

Bias Assessment And Reduction In Kernel Smoothing, Wenkai Ma

Electronic Thesis and Dissertation Repository

When performing local polynomial regression (LPR) with kernel smoothing, the choice of the smoothing parameter, or bandwidth, is critical. The performance of the method is often evaluated using the Mean Square Error (MSE). Bias and variance are two components of MSE. Kernel methods are known to exhibit varying degrees of bias. Boundary effects and data sparsity issues are two potential problems to watch for. There is a need for a tool to visually assess the potential bias when applying kernel smooths to a given scatterplot of data. In this dissertation, we propose pointwise confidence intervals for bias and demonstrate a …

Stable Carbon Isotope Variations Of Organic Matter And N-Alkanes In The Plant-Bulk Soil-Clay Fraction Continuum, Alana Crump

Electronic Thesis and Dissertation Repository

Organic matter (OM) adsorbed to clay minerals in soils can have C/N similar to lacustrine algal matter. Accurate source identification of OM in sediments is crucial for predicting future climate change impacts in the Great Lakes region. We analyzed C/N, carbon-isotope compositions, n-alkane abundances and compound-specific carbon-isotope compositions of vegetation, soil, and OM associated with clay minerals in soils and glacial till in order to determine if (i) OM associated with clay minerals has unique signatures distinct from lacustrine algal matter and is traceable to modern vegetation, and (ii) if these signatures have been transferred to and preserved in …

Evidence For A Partially Stalled Γ Rotor In F, Angela Murcia Rios, Siavash Vahidi, Stanley D Dunn, Lars Konermann

Chemistry Publications

F₁-ATPase uses ATP hydrolysis to drive rotation of the γ subunit. The γ C-terminal helix constitutes the rotor tip that is seated in an apical bearing formed by α₃β₃. It remains uncertain to what extent the γ conformation during rotation differs from that seen in rigid crystal structures. Existing models assume that the entire γ subunit participates in every rotation. Here we interrogated E. coli F₁-ATPase by hydrogen-deuterium exchange (HDX) mass spectrometry. Rotation of γ caused greatly enhanced deuteration in the γ C-terminal helix. The HDX kinetics implied that most F_{1 …}

The Electrochemical Study Of Simulated Spent Nuclear Fuel (Simfuel) Corrosion Under Permanent Disposal Conditions, Ziyan Zhu

Electronic Thesis and Dissertation Repository

The safety assessment of spent nuclear fuel under permanent disposal conditions requires examination of the corrosion of the spent fuel waste form (UO₂) inside a failed waste container. The objective of this research project was to develop a detailed mechanism of the UO₂ corrosion process when exposed to groundwater. The redox conditions within a failed container in a deep geologic repository will be complex. The oxidant, H₂O₂, produced by the α-radiolysis of groundwater, will be the main driving force for fuel corrosion. However, the efficiency of fuel dissolution will be determined by the …

Trends In Obesity And Multimorbidity In Canada., Michael Lebenbaum, Gregory S Zaric, Amardeep Thind, Sisira Sarma

Epidemiology and Biostatistics Publications

Very few studies have examined trends in multimorbidity over time and even fewer have examined trends over time across different body mass index (BMI) groups. Given a general decline in death rates but increased cardiovascular risk factors among individuals with obesity, the trend in the association between obesity and multimorbidity is hypothesized to be increasing over time. The data for our study came from the 1996-97 National Population Health Survey and the 2005 and 2012-13 Canadian Community Health Surveys (N = 277,366 across all 3 surveys). We examined trends in the association between BMI groups and multimorbidity using a logistic …

Pressure Tuning Of Energy Storage Materials Probed By In-Situ Vibrational Spectroscopy And Synchrotron Radiation, Pan Wang

Electronic Thesis and Dissertation Repository

Clean and renewable energy has drawn much attention recently due to the increasing demand for more energy and environmental issues. New materials have been developed and the improved performance of such materials have been achieved in the past decades. It has been proved that application of external high pressure can significantly tune the structure of materials. Consequently, the properties of the materials could also be modified. Therefore, in this thesis, we focused on the high-pressure studies of two classes of energy storage materials, hydrogen storage materials and solar cell materials. Ammonia borane (AB) has been extensively investigated as an excellent …

Bifurcation Analysis Of Two Biological Systems: A Tritrophic Food Chain Model And An Oscillating Networks Model, Xiangyu Wang

Electronic Thesis and Dissertation Repository

In this thesis, we apply bifurcation theory to study two biological systems. Main attention is focused on complex dynamical behaviors such as stability and bifurcation of limit cycles. Hopf bifurcation is particularly considered to show bistable or even tristable phenomenon which may occur in biological systems. Recurrence is also investigated to show that such complex behavior is common in biological systems.

First we consider a tritrophic food chain model with Holling functional response types III and IV for the predator and superpredator, respectively. Main attention is focused on the sta- bility and bifurcation of equilibria when the prey has a …

The Effect Of Sub-Facet Scale Geometry On Vertical Facet Temperatures In Urban Street Canyons, Rainer V.J. Hilland

Electronic Thesis and Dissertation Repository

Surface temperature plays a key role in many micro-scale urban processes. Walls comprise a significant percentage of the urban surface, yet are under-represented by many methods of thermal remote sensing and not considered in detail by micro-scale surface temperature mod- els. This thesis presents a novel method of mobile thermal observation performed in urban street canyons in London, ON that uses a thermal imager as well as a visual spectrum camera to provide dense spatial and temporal resolution of micro-scale wall temperature distributions. Images are manually classified by a series of nominal variables and the resulting data set discusses the …

Ecology And Evolution Of Dispersal In Metapopulations, Jingjing Xu

Electronic Thesis and Dissertation Repository

Dispersal plays a key role in the persistence of metapopulations, as the balance between local extinction and colonization is affected by dispersal. Herein, I present three pieces of work related to dispersal. The first two are devoted to the ecological aspect of delayed dispersal in metapopulations. The first one focuses on how dispersal may disrupt the social structure on patches from which dispersers depart. Examinations of bifurcation diagrams of the dynamical system show a metapopulation will, in general, be either in the state of global extinction or persistence, and dispersal only has a limited effect on metapopulation persistence. The second …

Computational Studies On Nucleic Acid-Ion Interactions In Droplets And Bulk Solution, Mahmoud Sharawy

Electronic Thesis and Dissertation Repository

Interactions of macromolecules with ions in solution have a long history of study because of their ubiquitous nature. These interactions are essential for the stability and function of macromolecules such as nucleic acids. Nucleic acids are involved in many natural biochemical processes. For example, deoxyribonucleic acid (DNA) provides more than storage of genetic information. The guanine-rich structures, at the ends of the DNA, participate in regulating the gene expression in the living cell by forming guanine quadruplex (G-quadruplex) structures. These structures provide a possible drug target for the treatment of cancer. Nucleic acids are polyions under physiological pH of 7.4. …