Physical Sciences and Mathematics Commons^™

Creating Calibration Curves Using In Situ X-Ray Diffraction To Determine The Shock Pressure Experienced By Clinopyroxene, Laura Jenkins

Electronic Thesis and Dissertation Repository

This work extends on two quantitative methods for evaluating shock metamorphism to include clinopyroxene using X-ray diffraction (XRD). Clinopyroxene samples experimentally shocked to known shock pressures were studied with XRD. Lattice strain (ε) and strain-related mosaicity (SRM) were measured for each sample and plotted against their known shock pressures, creating a ε versus shock pressure calibration curve and an SRM versus shock pressure calibration curve. These calibration curves were applied to three meteorites: Nakhla, Zagami, and ALHA 77005. The SRM calibration curve gave peak shock pressures of 12±8 GPa for Nakhla, 44±8 GPa for Zagami, and 68±8 GPa for ALHA …

Classification With Measurement Error In Covariates Or Response, With Application To Prostate Cancer Imaging Study, Kexin Luo

Electronic Thesis and Dissertation Repository

The research is motivated by the prostate cancer imaging study conducted at the University of Western Ontario to classify cancer status using multiple in-vivo images. The prostate cancer histological image and the in-vivo images are subject to misalignment in the co-registration procedure, which can be viewed as measurement error in covariates or response. We investigate methods to correct this problem.

The first proposed method corrects the predicted class probability when the data has misclassified labels. The correction equation is derived from the relationship between the true response and the error-prone response. The probability for the observed class label is adjusted …

Spatiotemporal Forecasting At Scale, Rafael Felipe Nascimento De Aguiar

Electronic Thesis and Dissertation Repository

Spatiotemporal forecasting can be described as predicting the future value of a variable given when and where it will happen. This type of forecasting task has the potential to aid many institutions and businesses in asking questions, such as how many people will visit a given hospital in the next hour. Answers to these questions have the potential to spur significant socioeconomic impact, providing privacy-friendly short-term forecasts about geolocated events, which in turn can help entities to plan and operate more efficiently. These seemingly simple questions, however, present complex challenges to forecasting systems. With more GPS-enabled devices connected every year, …

Porous Membranes From 2d Materials And Their Integration Into Chemiresistive Sensors For In-Line Detection Of Cadmium In Water Filtration Devices, Sheldon Van Middelkoop

Electronic Thesis and Dissertation Repository

As the global population increases, the need for drinking water is an ever-present concern. Water contamination from cadmium needs to be avoided due to the damaging effects of Cd dications to the human health. The Environmental Protection Agency (EPA) has set an extremely low permissible limit for Cd²⁺ in water, at 5 parts-per-billion (PPB), which poses extreme challenges towards Cd²⁺ detection and retention in specific water purification devices. This has led to a rush in the development of low-cost and scalable devices with in-line Cd²⁺sensing capabilities, with the ability to simultaneously purify water and monitor its …

The Reactivity Of Ditetrelenes Towards Organophosphorus Oxides, Maissa Belcina

Electronic Thesis and Dissertation Repository

The reactivity of tetramesityldisilene 4 and tetramesityldigermene 5 towards organophosphorus oxides was explored in this thesis. The reaction of dialkyl and diarylphosphine oxides and phosphites with ditetrelenes 4 and 5 resulted in a 1,3-addition to form diorganodisilyl and digermyl phosphinites 27, 28, 31, 32 and disilyl phosphites 35 and 36. The 1,3-addition resulted in a mild two electron reduction of the P(V) centre of the phosphine oxide and phosphite to a P(III) centre in the products, without the use of heat or a catalyst. The reaction of organophosphorus oxides provides another example of a main group …

Torsors Over Simplicial Schemes, Alexander S. Rolle

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Let X be a simplicial object in a small Grothendieck site C, and let G be a sheaf of groups on C. We define a notion of G-torsor over X, generalizing a definition of Gillet, and prove that there is a bijection between the set of isomorphism classes of G-torsors over X, and the set of maps in the homotopy category of simplicial presheaves on C, with respect to the local weak equivalences, from X to BG. We prove basic results about the resulting non-abelian cohomology invariant, including an exact sequence associated to a central extension of sheaves of groups, …

Polynomial And Rational Convexity Of Submanifolds Of Euclidean Complex Space, Octavian Mitrea

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The goal of this dissertation is to prove two results which are essentially independent, but which do connect to each other via their direct applications to approximation theory, symplectic geometry, topology and Banach algebras. First we show that every smooth totally real compact surface in complex Euclidean space of dimension 2 with finitely many isolated singular points of the open Whitney umbrella type is locally polynomially convex. The second result is a characterization of the rational convexity of a general class of totally real compact immersions in complex Euclidean space of dimension n..

Of Matroid Polytopes, Chow Rings And Character Polynomials, Ahmed Ashraf

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Matroids are combinatorial structures that capture various notions of independence. Recently there has been great interest in studying various matroid invariants. In this thesis, we study two such invariants: Volume of matroid base polytopes and the Tutte polynomial. We gave an approach to computing volume of matroid base polytopes using cyclic flats and apply it to the case of sparse paving matroids. For the Tutte polynomial, we recover (some of) its coefficients as degrees of certain forms in the Chow ring of underlying matroid. Lastly, we study the stability of characters of the symmetric group via character polynomials. We show …

Incorporation Of Fluorine Into Peptides And One-Bead One-Compound Libraries Through Copper-Free Click Chemistry For The Discovery Of Radiopharmaceuticals, Emily M. Murrell

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Molecular imaging is making possible the understanding of intricate biological processes in real-time in both healthy and diseased tissues. The ability to non-invasively locate biomarkers of disease with good sensitivity and specificity affords the ability to provide accurate and early diagnoses, and patient stratification for therapy. The chemokine receptor CXCR4 is one biomarker of interest, as it is overexpressed in many cancers, yet has low expression elsewhere in normal physiology. This thesis will document a method of combinatorial chemistry to construct libraries of new potential peptide-based imaging agents for positron emission tomography (PET) imaging. It will also incorporate the study …

Essential Dimension Of Parabolic Bundles, Dinesh Valluri

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Essential dimension of a geometric object is roughly the number of algebraically independent parameters needed to define the object. In this thesis we give upper bounds for the essential dimension of parabolic bundles over a non-singular curve X of genus g greater than or equal to 2 using Borne's correspondence between parabolic bundles on a curve and vector bundles on a root stack. This is a generalization of the work of Biswas, Dhillon and Hoffmann on the essential dimension of vector bundles, by following their method for curves and adapting it to root stacks. In this process, we invoke the …

Advances In Moment-Based Distributional Methodologies, Yishan Zang

Electronic Thesis and Dissertation Repository

This thesis comprises various results that rely on the moments of a distribution or the sample moments associated with a set of observations. Since a sample of size n is uniquely specified by its first n moments, it is pertinent to make use of sample moments for modeling, classification or inference purposes. Three density mixtures are approximated by adjusting in various ways an initial density approximation referred to a base density by means certain moment-based functions, and the accuracy of the resulting density approximants are compared. A similar study is carried out in the context of density estimation. Moreover, it …

Ricci Curvature Of Noncommutative Three Tori, Entropy, And Second Quantization, Rui Dong

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In noncommutative geometry, the metric information of a noncommutative space is encoded in the data of a spectral triple $(\mathcal{A}, \mathcal{H},D)$, where $D$ plays the role of the Dirac operator acting on the Hilbert space of spinors. Ideas of spectral geometry can then be used to define suitable notions such as volume, scalar curvature, and Ricci curvature. In particular, one can construct the Ricci curvature from the asymptotic expansion of the heat trace $\textrm{Tr}(e^{-tD^2})$. In Chapter 2, we will compute the Ricci curvature of a curved noncommutative three torus. The computation is done for both conformal and a non-conformal perturbation …

Exploring The Estimability Of Mark-Recapture Models With Individual, Time-Varying Covariates Using The Scaled Logit Link Function, Jiaqi Mu

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Mark-recapture studies are often used to estimate the survival of individuals in a population and identify factors that affect survival in order to understand how the population might be affected by changing conditions. Factors that vary between individuals and over time, like body mass, present a challenge because they can only be observed when an individual is captured. Several models have been proposed to deal with the missing-covariate problem and commonly impose a logit link function which implies that the survival probability varies between 0 and 1. In this thesis I explore the estimability of four possible models when survival …

Split Credibility: A Two-Dimensional Semi-Linear Credibility Model, Jingbing Qiu

Electronic Thesis and Dissertation Repository

In the thesis, we introduce a two-dimensional semi-linear credibility model, which is an extension of the classical credibility or split credibility models used by practicing actuaries. Our model predicts the future expected losses of a policyholder by considering its historical primary and excess losses. The optimal split point is derived based on the mean squared error criterion. We show when and why splitting a policyholder’s historical losses into primary and excess parts work analytically. In addition, we derived formulas for estimating our model parameters nonparametrically. Finally, we show the application of our model through three examples.

A Tropospheric Water Vapour Climatology And Trends Derived From Vibrational Raman Lidar Measurements Over Switzerland, Shannon Hicks-Jalali

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Water vapour is the most effective atmospheric greenhouse gas in terms of warming the atmosphere. Water vapour can magnify the temperature increase that CO₂ would cause alone by 2-3 times. As such, it is critical to monitor changes in water vapour abundance to better understand its role in atmospheric change. I have used 10 years of lidar and radiosonde measurements from the MeteoSwiss research station in Payerne, Switzerland to calibrate the lidar, improve its water vapour retrievals, and finally calculate a lidar water vapour climatology and trend analysis.

Calculating trends with a lidar requires rigorous calibration. Therefore, my first …

Development Of A 1-Dimensional Data Assimilation To Determine Temperature And Relative Humidity Combining Raman Lidar Backscatter Measurements And A Reanalysis Model, Shayamila N. Mahagammulla Gamage

Electronic Thesis and Dissertation Repository

Water vapor is the most dominant greenhouse gas in Earth's atmosphere. It is highly variable and its variations strongly depend on changes in temperature. Atmospheric water vapor can be expressed as relative humidity (RH), the ratio of the partial pressure of water vapor in the mixture to the equilibrium vapor pressure of water over a flat surface of pure water at a given temperature. Liquid water can exist as super-cooled water for temperatures between 0C to -38C. Thus, RH can be measured either relative to water (RHw) or to ice (RHi). RHi measurements are important in the upper tropospheric region, …

Synchrotron Radiation Analysis Of Daguerreotypes: Surface Characterization, Electrocleaning, And Preservation, Madalena S. Kozachuk

Electronic Thesis and Dissertation Repository

The first commercially viable photographic image, the daguerreotype, captured images from 1839 to 1860. While daguerreotypes provide a significant historical record of 19^th century individuals and events, deterioration now disfigures many of these images. This work describes the application of synchrotron radiation (SR) to the study of daguerreotypes.

Three goals were addressed in this thesis: 1) to utilize SR to further elucidate the physics and chemistry of the daguerreotype and how the surface varies with time, 2) to study the effects of the electrocleaning system on the daguerreotype surface, and 3) to propose suggestions to improve their preservation and …

Some Recent Developments On Pareto-Optimal Reinsurance, Wenjun Jiang

Electronic Thesis and Dissertation Repository

This thesis focuses on developing Pareto-optimal reinsurance policy which considers the interests of both the insurer and the reinsurer. The optimal insurance/reinsurance design has been extensively studied in actuarial science literature, while in early years most studies were concentrated on optimizing the insurer’s interests. However, as early as 1960s, Borch argued that “an agreement which is quite attractive to one party may not be acceptable to its counterparty” and he pioneered the study on “fair” risk sharing between the insurer and the reinsurer. Quite recently, the question of how to strike a balance in risk sharing between an insurer and …

Synthesis, Characterization, And Applications Of Group 13 And 14 Complexes Of Chelating Formazanate Ligands, Ryan R. Maar

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis and characterization of group 13 (boron and aluminum) and group 14 (silicon, germanium, and tin) complexes supported by chelating formazanate [R¹-N-N=C(R³)-N=N-R⁵]^‒ ligands. The resulting complexes are redox-active and often luminescent. Chapters two to four describe the synthesis and characterization of boron formazanate adducts. The work in these chapters demonstrates that through structural modification of the formazanate ligand, solid-state- and NIR photoluminescence can be achieved. Furthermore, the formation of an oxoborane (B=O) afforded a highly photoluminescent formazanate adduct due to the structural rigidity imposed by the B=O bond. These …

Using Stable Isotopes To Understand Survival Versus Extinction Of Late Pleistocene Muskoxen, Stephanie Mabee

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This thesis uses stable isotopes to investigate the adaptive advantages of Ovibos moschatus, a muskox, relative to now-extinct Pleistocene megafauna in eastern Beringia (Yukon Territory and Alaska), including another muskox Bootherium bombifrons. Ecological niches were defined for Ovibos and Bootherium using stable carbon and nitrogen isotope compositions of bone collagen. Plant remains trapped in modern Ovibos molars were used to determine the carbon and nitrogen isotope collagen-diet discrimination factors, which were then applied to ancient specimens. Ovibos possessed larger isotopic – and hence ecological – niches than Bootherium across eastern Beringian sites. The larger niche suggests that Ovibos …

Calcium Isotopes In The Saint Agatha Kettle Lake Deposits Of Southern Ontario, Emma-Dawn Ferguson

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The St. Agatha kettle lake deposits, ON, Canada, contain a thick section of endogenic marl and coeval shelly fauna. Marl accumulation occurred from ~13,500 to ~8,200 cal yrs BP. This study examines controls on marl and shell δ^44/42Ca, element ratios (Mg, Fe, and Ba), δ¹⁸O, δ¹³C, and ⁸⁷Sr/⁸⁶Sr ratios of marl calcite, shell aragonite, groundwater, and bedrock as proxies for paleolacustrine conditions. Results for Interval A (532.0 to 475.0cm) indicates a cooler, wetter climate, lower primary lake productivity and higher lake levels. Interval B (475.0 to 345.0cm) marks the onset of …

Localization Theory In An Infinity Topos, Marco Vergura

Electronic Thesis and Dissertation Repository

We develop the theory of reflective subfibrations on an ∞-topos E. A reflective subfibration L on E is a pullback-compatible assignment of a reflective subcategory D_X ⊆ E/X with associated localization functor L_X, for every X in E. Reflective subfibrations abound in homotopy theory, albeit often disguised, e.g., as stable factorization systems. The added properties of a reflective subfibration L on E compared to a mere reflective subcategory of E are crucial for most of our results. For example, we can prove that L-local maps (i.e., those maps p in D_X for some X in E) admit a classifying map. …

Bed Particle Displacement In A Wandering Gravel-Bed River, Ryan Mcqueen

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The primary goal of this thesis was to investigate the influence of channel morphology on individual bed particle path lengths in a wandering gravel bed river, the San Juan River, BC. This was achieved through tracking the transport of sedimentary particles using PIT tags and also capturing changes in channel morphology through repeat topographic surveys over the same three year time period as the tracer tracking. Particle transport tended to remain within the riffle-pool-bar sequence in which they were seeded, with modal path lengths related to areas of deposition along bar margins, especially at the bar apex region. This aligned …

Evaluating Zircon Strain Chronometry Of A Grenville Front Deformation Fabric Through Microstructural Analysis And Quartz Piezometry, Kaitlyn Petkau

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Zircon strain chronometry can allow correlation of isotopic ages with microstructural fabrics to place an absolute age on the timing of deformation. However, the general applicability of zircon strain chronometry to problems in regional continental tectonics is still being tested and this study is the first effort to apply the approach to the ~1 Ga (billion year old) Grenville Province of the Precambrian Canadian Shield. Samples were analyzed from the 1747 +6/-5 Ma Wanapitei Complex, a poly-deformed mafic metaplutonic body that preserves fabric evidence for several stages in the tectonic history of the Grenville Front. This study is the first …

A Computationally Efficient Methodology In Pricing A Guaranteed Minimum Accumulation Benefit, Yiming Huang

Electronic Thesis and Dissertation Repository

In this thesis, we consider a framework under which three correlated factors, namely, financial, mortality and lapse risks, are modelled in an integrated way. This modelling framework supports the valuation of a guaranteed minimum accumulation benefit (GMAB). The change-of-measure approach is employed to come up with a compact and implementable valuation expressions. We provide a numerical demonstration to confirm the efficiency and accuracy of our proposed pricing methodology. In particular, our approach on average takes only 0.07% of the computing time entailed by the Monte-Carlo (MC) simulation technique. Furthermore, the standard errors of our approach’s results are lower than those …

Graded Character Rings, Mackey Functors And Tambara Functors, Beatrice Isabelle Chetard

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Let $G$ be a finite group. The ring $R_\KK(G)$ of virtual characters of $G$ over the field $\KK$ is a $\lambda$-ring; as such, it is equipped with the so-called $\Gamma$-filtration, first defined by Grothendieck. In the first half of this thesis, we explore the properties of the associated graded ring $R^*_\KK(G)$, and present a set of tools to compute it through detailed examples. In particular, we use the functoriality of $R^*_\KK(-)$, and the topological properties of the $\Gamma$-filtration, to explicitly determine the graded character ring over the complex numbers of every group of order at most $8$, as well as …

Development Of Bioorthogonal Molecular Tools On Gold Nanoparticles, Wilson Luo

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This thesis describes the development of bioorthogonal chemical tools — originally designed to form bonds cleanly and selectively in living systems — on gold nanoparticles (AuNPs) as a model reactive nanomaterial template to showcase chemical modifications in a facile and robust manner. To achieve this goal, new methodologies to cleanly incorporate strained alkyne (SA) and cargo-bearing triarylphosphine derivatives onto AuNPs were developed. The protocols described herein provide well-defined reactive AuNP interfaces that undergo bioorthogonal bond-forming and breaking reactions cleanly, selectively, and rapidly to enable chemical tuning of their properties and function.

In order to circumvent the high reactivity of SAs, …

Allostratigraphy And Sedimentology Of The Muskiki And Marshybank Members Of The Wapiabi Formation (Upper Cretaceous, Coniacian) In Southwestern Alberta, Canada, Elizabeth Hooper

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The marine mudstone-dominated, Muskiki and Marshybank members of the Wapiabi Formation occupy the central foredeep of the Western Canada Foreland Basin. These Coniacian (86.3-89.8 Ma) rocks form a ~100 m thick, overall shallowing-upward depositional succession that records a basin-scale transgressive-regressive event following an early Coniacian lowstand. The strata, deposited on a low-gradient storm- dominated marine ramp, contain numerous well-preserved molluscan fossils and comprise many upward-coarsening successions (5-15 m thick). Detailed correlation integrates biostratigraphic and lithologic data from 14 cores and 13 outcrops into a regional (~45,000 km2) allostratigraphic framework constructed from 1020 wireline logs. This integrated stratigraphy provides a basis …

Algebraic Neural Architecture Representation, Evolutionary Neural Architecture Search, And Novelty Search In Deep Reinforcement Learning, Ethan C. Jackson

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Evolutionary algorithms have recently re-emerged as powerful tools for machine learning and artificial intelligence, especially when combined with advances in deep learning developed over the last decade. In contrast to the use of fixed architectures and rigid learning algorithms, we leveraged the open-endedness of evolutionary algorithms to make both theoretical and methodological contributions to deep reinforcement learning. This thesis explores and develops two major areas at the intersection of evolutionary algorithms and deep reinforcement learning: generative network architectures and behaviour-based optimization. Over three distinct contributions, both theoretical and experimental methods were applied to deliver a novel mathematical framework and experimental …

Microfacies Analysis Of Mudstone In A Freshwater To Marine Transect: Upper Cretaceous Dunvegan And Kaskapau Formations, Western Canada Foreland Basin, Katharin Pavan

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In the Cenomanian-Turonian Dunvegan and Kaskapau formations in Alberta and British Columbia, terrestrial, and nearshore to offshore environments can be related temporally and spatially using a well-established allostratigraphic framework. In these varied environments, ten mudstone microfacies were identified, using optical and scanning electron microscopy. Microfacies 1 through 3 were deposited in a freshwater lacustrine environment by hyperpycnal flows, and consist of rippled, structureless, and inverse-to-normally graded thin beds that record turbulent, laminar, and waxing and waning flow. Microfacies 4 and 5 were deposited from turbulent flow in a fluvial environment. Microfacies 6 represents a paleosol that underlies a maximum flooding …