Physical Sciences and Mathematics Commons^™

An Adaptive Weighted Average (Wav) Reprojection Algorithm For Image Denoising, Halimah Alsurayhi

Electronic Thesis and Dissertation Repository

Patch-based denoising algorithms have an effective improvement in the image denoising domain. The Non-Local Means (NLM) algorithm is the most popular patch-based spatial domain denoising algorithm. Many variants of the NLM algorithm have proposed to improve its performance. Weighted Average (WAV) reprojection algorithm is one of the most effective improvements of the NLM denoising algorithm. Contrary to the NLM algorithm, all the pixels in the patch contribute into the averaging process in the WAV reprojection algorithm, which enhances the denoising performance. The key parameters in the WAV reprojection algorithm are kept fixed regardless of the image structure. In this thesis, …

Virtual Sensor Middleware: A Middleware For Managing Iot Data For The Fog-Cloud Platform, Fadi Almahamid

Electronic Thesis and Dissertation Repository

Internet of Things is a massively growing field where billions of devices are connected to the Internet using different protocols and produce an enormous amount of data. The produced data is consumed and processed by different applications to make operations more efficient. Application development is challenging, especially when applications access sensor data since IoT devices use different communication protocols.

The existing IoT architectures address some of these challenges. This thesis proposes an IoT Middleware that provides applications with the abstraction required of IoT devices while distributing the processing of sensor data to provide a real-time or near real-time response and …

Incorporating Figure Captions And Descriptive Text Into Mesh Term Indexing: A Deep Learning Approach, Xindi Wang

Electronic Thesis and Dissertation Repository

The exponential increase of available documents online makes document classification an important application in natural language processing. The goal of text classification is to automatically assign categories to documents. Traditional text classifiers depend on features, such as, vocabulary and user-specified information which mainly relies on prior knowledge. In contrast, deep learning automatically learns effective features from data instead of adopting human-designed features. In this thesis, we specifically focus on biomedical document classification. Beyond text information from abstract and title, we also consider image and table captions, as well as paragraphs associated with images and tables, which we demonstrate to be …

Impact Cratering Processes On The Earth And Moon: Meteorites, Complex Craters, And The Origin Of The Moon, Patrick Hill

Electronic Thesis and Dissertation Repository

This thesis seeks to understand the mechanism of hypervelocity impacts, lunar origin and geology, and stable isotope techniques and its application to lunar material. Three lunar regolith breccias, Dhofar 1673, Dhofar 1983, and Dhofar 1984, were examined. The petrography, mineralogy, isotope chemistry, and bulk chemistry of these meteorites were quantified to investigate their origin. The chemistry of the impact melt rock and bulk chemical analysis suggests sourcing from either the Feldspathic or Outer Feldspathic Highland Terranes. Given the similarities in the meteorites, and the proximal location of each find (within 500 m), this thesis proposes strong evidence for their pairing. …

Characteristics Of Impactites In The Central Uplift Of The Mistastin Lake Impact Structure, Canada, Alaura Singleton

Electronic Thesis and Dissertation Repository

This thesis investigated the nature of parautochthonous and allochthonous impactites found in the erosional remnant of the central uplift of the Mistastin Lake impact structure, central Labrador. This was carried out with the goal of discovering details about the composition and formation conditions of these complex materials. This study involved fieldwork and a range of laboratory techniques. As part of this work, a geological map of Horseshoe Island has been created, and is the most detailed to date. The shock metamorphic features found in the uplifted target rocks have been assessed, and indicate a peak shock level of 5a (35-45 …

Non-Traditional Metallation Of Metallothioneins With Xenobiotic Therapeutic Metals, Daisy L. Wong

Electronic Thesis and Dissertation Repository

The rise of the Anthropocene has seen more global pollution than before in history. With the explosion of consumer electronics in the last half century, the rise of metal pollution from their extraction and disposal results in the unnatural introduction of heavy and rare metals into the ecosystem. Organisms have a metal defense protein, metallothionein, which has multiple roles in essential metal regulation and protection against minimal toxic metal exposure. However, these modern heavy metals prominent in electronics are not found biologically and their interactions in the body are generally unknown. Some of these metals are employed as therapeutic agents …

Investigating The Rotary Mechanism Of Atp Synthase Using Molecular Dynamics Simulations, Angela Marcela Murcia Rios

Electronic Thesis and Dissertation Repository

F₁-ATPase is a motor protein that can use ATP hydrolysis to drive rotation of the central subunit. The γ C-terminal helix constitutes of the rotor tip that is seated in an apical bearing formed by the α₃β₃ head. 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 develop a molecular dynamics (MD) strategy to model the off-axis forces acting on γ in F₁-ATPase. MD runs showed stalling of the …

Machine Learning For Stock Prediction Based On Fundamental Analysis, Yuxuan Huang

Electronic Thesis and Dissertation Repository

Application of machine learning for stock prediction is attracting a lot of attention in recent years. A large amount of research has been conducted in this area and multiple existing results have shown that machine learning methods could be successfully used toward stock predicting using stocks’ historical data. Most of these existing approaches have focused on short term prediction using stocks’ historical price and technical indicators. In this thesis, we prepared 22 years’ worth of stock quarterly financial data and investigated three machine learning algorithms: Feed-forward Neural Network (FNN), Random Forest (RF) and Adaptive Neural Fuzzy Inference System (ANFIS) for …

Improving Neural Sequence Labelling Using Additional Linguistic Information, Muhammad Rifayat Samee

Electronic Thesis and Dissertation Repository

Sequence Labelling is the task of mapping sequential data from one domain to another domain. As we can interpret language as a sequence of words, sequence labelling is very common in the field of Natural Language Processing (NLP). In NLP, some fundamental sequence labelling tasks are Parts-of-Speech Tagging, Named Entity Recognition, Chunking, etc. Moreover, many NLP tasks can be modeled as sequence labelling or sequence to sequence labelling such as machine translation, information retrieval and question answering. An extensive amount of research has already been performed on sequence labelling. Most of the current high performing models are neural network models. …

Haptics-Enabled, Gpu Augmented Surgical Simulation Platform For Glenoid Reaming, Vlad Popa

Electronic Thesis and Dissertation Repository

Surgical simulators are technological platforms that provide virtual substitutes to the current cadaver-based medical training models. The advantages of exposure to these devices have been thoroughly studied, with enhanced surgical proficiency being one of the assets gained after extensive use. While simulators have already penetrated numerous medical domains, the field of orthopedics remains stagnant despite a demand for the ability to practice uncommon surgeries, such as total shoulder arthroplasty (TSA). Here we extrapolate the algorithms of an inhouse software engine revolving around glenoid reaming, a critical step of TSA. The project’s purpose is to provide efficient techniques for future simulators, …

A Survey Of Numerical Quadrature Methods For Highly Oscillatory Integrals, Jeet Trivedi

Electronic Thesis and Dissertation Repository

In this thesis, we examine the main types of numerical quadrature methods for a special subclass of one-dimensional highly oscillatory integrals. Along with a presentation of the methods themselves and the error bounds, the thesis contains implementations of the methods in Maple and Python. The implementations take advantage of the symbolic computational abilities of Maple and allow for a larger class of problems to be solved with greater ease to the user. We also present a new variation on Levin integration which uses differentiation matrices in various interpolation bases.

Calculating The Dimensionality Of The Brain, And Other Applications Of An Optimized Generalized Ising Model In Predicting Brain's Spontaneous Functions, Pubuditha M. Abeyasinghe

Electronic Thesis and Dissertation Repository

Understanding a system as complex as the human brain is a very demanding task. Directly working with structural and functional neuroimaging data has led to most of the understanding we have gained about the human brain. However, performing only the direct statistical comparisons on the empirical function and the structure does not fully explain the observed long-range functional correlations. Therefore, implementations of mathematical models to gain further understanding of the relationship between the structure and function of the brain is critical. Additionally, spontaneous functions of the brain can only be predicted using computer simulated models; which will be pivotal for …

Future Changes Of Hydroclimatic Extremes In Western North America Using A Large Ensemble: The Role Of Internal Variability, Mohammad Hasan Mahmoudi

Electronic Thesis and Dissertation Repository

Increases in the intensity and frequency of extreme events in Western North America (WNA) can cause significant socioeconomic problems and threaten existing infrastructure. In this study we analyze the impacts of climate change on hydroclimatic extremes and assess the role of internal variability over WNA, which collectively drain an area of about 1 million km². We used gridded observations and downscaled precipitation, maximum and minimum temperature from seven General Circulation Models (GCMs) that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and a large ensemble of CanESM2 model simulations (CanESM2-LE; 50 members) for this analysis. Spatial …

Applicability Of Recurrent Neural Networks To Player Data Analysis In Freemium Video Games, Jonathan Tan

Electronic Thesis and Dissertation Repository

We demonstrate the applicability and practicality of recurrent neural networks (RNNs), a machine learning methodology suited for sequential data, on player data from the mobile video game My Singing Monsters. Since this data comes in as a stream of events, RNNs are a natural solution for analyzing this data with minimal preprocessing. We apply RNNs to monitor and forecast game metrics, predict player conversion, estimate lifetime player value, and cluster player behaviours. In each case, we discuss why the results are interesting, how the trained models can be applied in a business setting, and how the preliminary work can …

Valuation And Risk Management Of Some Longevity And P&C Insurance Products, Yixing Zhao

Electronic Thesis and Dissertation Repository

Numerous insurance products linked to risky assets have emerged rapidly in the last couple of decades. These products have option-embedded features and typically involve at least two risk factors, namely interest and mortality risks. The need for models to capture risk factors' behaviours accurately is enormous and critical for insurance companies. The primary objective of this thesis is to develop pricing and hedging frameworks for option-embedded longevity products addressing correlated risk factors. Various methods are employed to facilitate the computation of prices and risk measures of longevity products including those with maturity benefits. Furthermore, in order to be prepared for …

Approximation Algorithms For Problems In Makespan Minimization On Unrelated Parallel Machines, Daniel R. Page

Electronic Thesis and Dissertation Repository

A fundamental problem in scheduling is makespan minimization on unrelated parallel machines (R||C_max). Let there be a set J of jobs and a set M of parallel machines, where every job J_j ∈ J has processing time or length p_i,j ∈ ℚ⁺ on machine M_i ∈ M. The goal in R||C_max is to schedule the jobs non-preemptively on the machines so as to minimize the length of the schedule, the makespan. A ρ-approximation algorithm produces in polynomial time a feasible solution such that its objective value is within a multiplicative factor ρ of …

Local Search Approximation Algorithms For Clustering Problems, Nasim Samei

Electronic Thesis and Dissertation Repository

In this research we study the use of local search in the design of approximation algorithms for NP-hard optimization problems. For our study we have selected several well-known clustering problems: k-facility location problem, minimum mutliway cut problem, and constrained maximum k-cut problem.

We show that by careful use of the local optimality property of the solutions produced by local search algorithms it is possible to bound the ratio between solutions produced by local search approximation algorithms and optimum solutions. This ratio is known as the locality gap.

The locality gap of our algorithm for the k-uncapacitated facility …

Considering A Seismically Active Leech River Valley Fault Zone In Southwestern British Columbia, Jacob J. Kukovica

Electronic Thesis and Dissertation Repository

The transpressional reverse Leech River fault (LRF) extends across the southern tip of Vancouver Island and beneath the city of Victoria, British Columbia, Canada. New paleoseismic studies suggest at least three surface-rupturing earthquakes have exceeded a moment magnitude (M) of 6 within a proposed Leech River Valley Fault Zone (LRVFZ) within the last 9,000 years. We examine the impact of an active LRVFZ to predicted earthquake ground motions for Victoria. In a probabilistic formulation considering the likelihood of all earthquake sources, LRVFZ earthquakes will contribute the most to high-frequency ground motions (≥ 10 Hz) in Victoria. The Canadian …

Algorithms For Bohemian Matrices, Steven E. Thornton

Electronic Thesis and Dissertation Repository

This thesis develops several algorithms for working with matrices whose entries are multivariate polynomials in a set of parameters. Such parametric linear systems often appear in biology and engineering applications where the parameters represent physical properties of the system. Some computations on parametric matrices, such as the rank and Jordan canonical form, are discontinuous in the parameter values. Understanding where these discontinuities occur provides a greater understanding of the underlying system.

Algorithms for computing a complete case discussion of the rank, Zigzag form, and the Jordan canonical form of parametric matrices are presented. These algorithms use the theory of regular …

Extracting Scales Of Measurement Automatically From Biomedical Text With Special Emphasis On Comparative And Superlative Scales, Sara Baker

Electronic Thesis and Dissertation Repository

Abstract

In this thesis, the focus is on the topic of “Extracting Scales of Measurement Automatically from Biomedical Text with Special Emphasis on Comparative and Superlative Scales.” Comparison sentences, when considered as a critical part of scales of measurement, play a highly significant role in the process of gathering information from a large number of biomedical research papers. A comparison sentence is defined as any sentence that contains two or more entities that are being compared. This thesis discusses several different types of comparison sentences such as gradable comparisons and non-gradable comparisons. The main goal is extracting comparison sentences automatically …

Evaluating Restoration Success By Tracking The Structural And Functional Recovery Of Restored, Drained, And Intact Wetlands, Renee C. Howard

Electronic Thesis and Dissertation Repository

Wetland restoration efforts have increased on the Canadian prairies to compensate for widespread loss of wetland area, form, and function. Restoration activity presumes a direct replacement for natural wetlands, where restored wetlands provide equivalent ecological functions and services. However, restoration projects often show limited recovery success in biological structure and biogeochemical function. Using plant functional traits is an emerging approach to assessing ecological process and may provide a better indicator of wetland functional recovery than vegetation structural indicators alone. Here, I tracked vegetation structural metrics (i.e., species richness, composition, and cover) and plant functional traits over a chronosequence of restored …

Optimal Algorithms For Deriving Estimates Of Phytoplankton Biomass In Lakes From Landsat Satellite Imagery, Michael A. Dallosch

Electronic Thesis and Dissertation Repository

The frequency, intensity, and geographical distribution of harmful phytoplankton blooms are on the rise globally. There is a scientific need for estimates of historical and current phytoplankton data. This research develops mathematical algorithms for accurate assessment of surface chlorophyll-a (chl-a), a proxy for phytoplankton biomass, within freshwater lakes. Landsat satellite images (4-5 TM, 7 ETM and 8 OLI) were used to create predictive models (from 1984 to 2017) for seven ecoregions (ranging from the tropics to arctic). Correlation tests for 82 algorithms were conducted to establish the best fit models (linear, exponential, logarithmic, power) for chl-a …

Sedimentology, Lithostratigraphy And Geochronology Of The Paleoproterozoic Gordon Lake Formation, Huronian Supergroup, Ontario, Canada, Carolyn M. Hill

Electronic Thesis and Dissertation Repository

The Gordon Lake Formation of the Paleoproterozoic Huronian Supergroup is a primarily-siliciclastic succession ranging from 300 to 1100 m thick. Lithostratigraphic and sedimentological analysis of the formation in the Bruce Mines and Flack Lake areas, and Killarney and Lady Evelyn-Smoothwater provincial parks revealed 7 lithofacies, which comprise 3 distinct lithofacies associations. The lithofacies associations are subtidal nearshore, subtidal to shallow shelf, and mixed intertidal flat. Microbially-induced sedimentary structures (MISS) related to microbial mat destruction and decay were recognized in the Flack Lake area. The preserved MISS include sand cracks, mat chips, remnant gas domes, and pyrite patches, and iron laminae. …

Corrosion Studies On Lightweight Automotive Alloys: The Effect Of Microstructure And Fundamental Mechanisms, Wilfred J. Binns

Electronic Thesis and Dissertation Repository

Owing to their excellent strength-to-weight ratio and low density, magnesium alloys have the potential to significantly reduce the weight of automobiles leading to decreased emissions and greater range for electrical vehicles. However, the practicality of magnesium alloys for automotive and aerospace applications is severely hindered by their poor corrosion resistance in aqueous environments. Despite intensive research effort, the underlying mechanism(s) responsible for this poor corrosion resistance remains elusive. Further complicating the situation is the presence of secondary microstructures which are necessary for desirable physical properties but lead to microgalvanic coupling which exacerbates the poor corrosion resistance of magnesium alloys. This …

Enhanced Koszulity In Galois Cohomology, Marina Palaisti

Electronic Thesis and Dissertation Repository

Despite their central role in Galois theory, absolute Galois groups remain rather mysterious; and one of the main problems of modern Galois theory is to characterize which profinite groups are realizable as absolute Galois groups over a prescribed field. Obtaining detailed knowledge of Galois cohomology is an important step to answering this problem. In our work we study various forms of enhanced Koszulity for quadratic algebras. Each has its own importance, but the common ground is that they all imply Koszulity. Applying this to Galois cohomology, we prove that, in all known cases of finitely generated pro-$p$-groups, Galois cohomology is …

Development Of In Situ Forming Hydrogels For Intra-Articular Drug Delivery, Andy Prince

Electronic Thesis and Dissertation Repository

Hydrogels are 3-dimensional crosslinked polymer networks that can absorb significant amounts of water. The physical properties associated with hydrogels affords them resemblance to biological tissues making them good candidates for biomedical applications. Many pharmaceuticals, specifically non-steroidal anti-inflammatory drugs (NSAIDs), have poor aqueous solubility, which limits their bioavailability and efficacy. People suffering from chronic osteoarthritis (OA) are required to frequently take large doses to mitigate pain, which can lead to serious side effects. Hydrogels are good strategies to deliver NSAIDs via articular injection because they can form solid gels in situ. This thesis describes the synthesis, formulation, mechanical testing, in …

The Impact-Generated Hydrothermal System Of The East Clearwater Lake Impact Structure, Quebec, Canada, Derek King

Electronic Thesis and Dissertation Repository

Alteration mineralization at impact craters gives insight into the hydrothermal system generated post-impact. This is the first work to document the alteration mineralization to characterize the East Clearwater impact-generated hydrothermal system. The East Clearwater hydrothermal system in the impact melt rocks and melt-bearing breccias transitions from zeolite-smectite assemblages to chlorite-dominant assemblages with depth. pH evolution of the East Clearwater impact-generated hydrothermal system reflects magmatic-driven hydrothermal systems in granitic rocks. West Clearwater has a different alteration style. Given an impact forms a hydrothermal system, the style of alteration will not only vary dependent on target lithologies (i.e., crystalline, sedimentary, mixed target), …

Vessel Tree Reconstruction With Divergence Prior, Zhongwen Zhang

Electronic Thesis and Dissertation Repository

Accurate structure analysis of high-resolution 3D biomedical images of vessels is a challenging issue and in demand for medical diagnosis nowadays. Previous curvature regularization based methods [10, 31] give promising results. However, their mathematical models are not designed for bifurcations and generate significant artifacts in such areas. To address the issue, we propose a new geometric regularization principle for reconstructing vector fields based on prior knowledge about their divergence. In our work, we focus on vector fields modeling blood flow pattern that should be divergent in arteries and convergent in veins. We show that this previously ignored regularization constraint can …

Thermal Performance And Sustainability Of Borehole Heat Exchangers Within Building Clusters, Ronan Drysdale

Electronic Thesis and Dissertation Repository

Geothermal energy has greatly increased in prevalence over the last 20 years. With many new installations, the desire to introduce geothermal energy into unused urban environments has increased. However the urban environment has a great effect on the subsurface thermal profile, which may significantly influence geothermal systems. To test the effectiveness and efficiency of different geothermal systems in tight building clusters, as well as the effects of the system on the subsurface, a three dimensional finite element model was developed. The model is based on an area of University of Western Ontario campus that has a geothermal system utilizing borehole …

Protein Conformations In The Gas Phase Probed By Mass Spectrometry And Molecular Dynamics Simulations, Maryam Bakhtiari

Electronic Thesis and Dissertation Repository

Mass Spectrometry (MS) has been revolutionized by the ability to produce intact gaseous protein ions by electrospray ionization (ESI). The question to what extent these ions retain solution-like conformations under “native” ESI conditions remains a matter of debate. Traditional high-resolution structure determination techniques only report on proteins in the condensed phase. For this reason, MD simulations play an important role in exploring the behavior of gas phase proteins. In this research, mobile and non-mobile proton MD simulations along with mass spectrometry data at 300 K in both positive and negative ion mode indicated that native-like conformations were largely retained. Surface …