Physical Sciences and Mathematics Commons^™

Core Formation In Partially Ionized Magnetic Molecular Clouds, Nicole D. Bailey

Electronic Thesis and Dissertation Repository

Linear analysis of the formation of protostellar cores in planar magnetic interstellar clouds shows that molecular clouds exhibit a preferred length scale for collapse that depends on the mass-to-flux ratio and neutral-ion collision time within the cloud. This linear analysis can be used to investigate the formation of star forming clusters and the distribution of mass within star forming regions. By combining the results of the linear analysis with a realistic ionization profile for the cloud, we find that a molecular cloud may evolve through two fragmentation events in the evolution toward the formation of stars. Our model suggests that …

Mapping And Zircon Geochronology Of The Lyon Inlet Boundary Zone, Nunavut; A Crustal Scale Break In The Churchill Province, Nikolas B. Ganderton

Electronic Thesis and Dissertation Repository

An important aspect of geology is the understanding of processes that created and modified continents and their resources. Knowledge of the age of formation and metamorphism of crystalline crust is thus important, and has been pursued in a recently discovered crustal-scale boundary on the southern Melville Peninsula (Nunavut, Canada) through field mapping, U-Pb zircon geochronology and electron beam analysis. This >250km-long crustal feature is termed here the Lyon Inlet Boundary Zone (LIBZ). Three samples from a 15 by 20 km map area reveal a complex Archean history with the dominant granitoid unit crystallizing at 2770±38 Ma and metamorphosed at 2670±36 …

An Architecture For Believable Socially Aware Agents, Arvand Dorgoly

Electronic Thesis and Dissertation Repository

The main focus of this thesis is to solve the believability problem in video game agents by integrating necessary psychological and sociological foundations by means of role based architecture. Our design agent also has the capability to reason and predict the decisions of other actors by using its own mental model. The agent has a separate mental model for every actor.

Comparison Of Option Pricing Between Arma-Garch And Garch-M Models, Yi Xi

Electronic Thesis and Dissertation Repository

Option pricing is a major area in financial modeling. Option pricing is sometimes based on normal GARCH models. Normal GARCH models fail to capture the skewness and the leptokurtosis in financial data. The variant GARCH-in-mean (GARCH-M) model is widely used in the option pricing literature. It adds a heteroskedasticity term to the mean equation, which is interpreted as a risk premium, and also incorporates a type of asymmetry.

Our goal is to compare option valuation between GARCH-M and ARMA-GARCH models with normal and non-normal, z-distributed innovations. The models are fitted to the historical return data, and risk neutral measures are …

A New Diagnostic Test For Regression, Yun Shi

Electronic Thesis and Dissertation Repository

A new diagnostic test for regression and generalized linear models is discussed. The test is based on testing if the residuals are close together in the linear space of one of the covariates are correlated. This is a generalization of the famous problem of spurious correlation in time series regression. A full model building approach for the case of regression was developed in Mahdi (2011, Ph.D. Thesis, Western University, ”Diagnostic Checking, Time Series and Regression”) using an iterative generalized least squares algorithm. Simulation experiments were reported that demonstrate the validity and utility of this approach but no actual applications were …

Joint Outcome Modeling Using Shared Frailties With Application To Temporal Streamflow Data, Lihua Li

Electronic Thesis and Dissertation Repository

Recently there has been tremendous interest in the development of tools for joint analysis of longitudinal data and time-to-event data. This has gained emphasis particularly in clinical studies, where longitudinal measurements on a response may be recorded along with a time-to-event outcome. Joint analysis of multiple outcomes beyond longitudinal and survival have also been considered, for example, joint analysis of a variety of generalized linear models including continuous and count data, or continuous and binomial data. With joint analysis of multiple outcomes, the interest may be analysis of one outcome conditional on the others, or, more typically, analysis of all …

Integrated Development And Parallelization Of Automated Dicentric Chromosome Identification Software To Expedite Biodosimetry Analysis, Yanxin Li

Electronic Thesis and Dissertation Repository

Manual cytogenetic biodosimetry lacks the ability to handle mass casualty events. We present an automated dicentric chromosome identification (ADCI) software utilizing parallel computing technology. A parallelization strategy combining data and task parallelism, as well as optimization of I/O operations, has been designed, implemented, and incorporated in ADCI. Experiments on an eight-core desktop show that our algorithm can expedite the process of ADCI by at least four folds. Experiments on Symmetric Computing, SHARCNET, Blue Gene/Q multi-processor computers demonstrate the capability of parallelized ADCI to process thousands of samples for cytogenetic biodosimetry in a few hours. This increase in speed underscores the …

Nfa Reduction Via Hypergraph Vertex Cover Approximation, Timothy Ng

Electronic Thesis and Dissertation Repository

In this thesis, we study in minimum vertex cover problem on the class of k-partite k-uniform hypergraphs. This problem arises when reducing the size of nondeterministic finite automata (NFA) using preorders, as suggested by Champarnaud and Coulon. It has been shown that reducing NFAs using preorders is at least as hard as computing a minimal vertex cover on 3-partite 3-uniform hypergraphs, which is NP-hard. We present several classes of regular languages for which NFAs that recognize them can be optimally reduced via preorders. We introduce an algorithm for approximating vertex cover on k-partite k-uniform hypergraphs based on a theorem by …

The Trentonian (Late Ordovician) Brachiopod Fauna Of Ontario: Evolution Through A Global Warming Event, Akbar Sohrabi Hashjin

Electronic Thesis and Dissertation Repository

This thesis, which examines the evolution of the Late Ordovician (early Katian) brachiopod fauna of Ontario, consists of two main parts: 1) a case study of the Late Ordovician Rhynchotrema–Hiscobeccus lineage of North America to investigate the morphological variations and evolutionary trends of brachiopod fauna in time and space, 2) the paleobiogeography of early Katian brachiopod fauna to explore their distribution patterns at a global scale and controlling factors.

During the Katian, the North American craton experienced a first-order marine transgression. The early stage of this event in the early Katian (Trentonian, Chatfieldian) was marked by the development …

Implementation,Validation And Application Of An Automated Motion Correction Algorithm In Hepatic Perfusion Ct For Image-Guided Radiotherapy, Nikolaj Kg Jensen

Electronic Thesis and Dissertation Repository

Functional imaging holds promise in guiding, evaluating and predicting efficacy of cancer treatment. Perfusion imaging provides high resolution functional information generated by applying a model to a dynamic series of contrast enhanced anatomical images.

The objectives of this thesis are: 1) to develop and validate a registration algorithm to reduce breathing motion artifacts in hepatic perfusion CT, and 2) to evaluate the potential of perfusion CT to improve radiotherapy of liver cancer.

An automated one-dimensional correlation-based registration algorithm was developed and validated in phantom and pig studies and against manual registration of patient scans. This algorithm was used to register …

A Variability Study Of The Typical Red Supergiant Antares A, Teznie J D Pugh

Electronic Thesis and Dissertation Repository

Red giants and red supergiants have long been known to be variable. In the last 40 years many of the features of this variability have been associated with large convective cells. Unfortunately, due to the long timescales of these variations they are not well studied, with the exception of the bright M-class supergiant Betelgeuse (α Orionis, M2 Iab). Betelgeuse has been well studied both observationally and theoretically, and has many features that are well described by models of convection. It was these studies of Betelgeuse that provided the main motivation for this thesis. We ask if the dramatic motions seen …

Ratio-Based Edge Detection Inspired Speckle Reducing Anisotropic Diffusion, Asaduzzaman Babu

Electronic Thesis and Dissertation Repository

Speckle Reducing Anisotropic Diffusion, SRAD, is a multiplicative speckle noise reduction method. In highly speckled environment, SRAD occasionally produces over-smoothed, dislocated/broadened edge lines and inadequate de-noising on homogeneous image regions where the speckles are well developed. Moreover, the performance of SRAD is highly dependent on the initial selection of a good homogeneous area. To overcome these weaknesses, we propose two different ratio-based edge detection inspired extensions to SRAD. One of the proposed extensions incorporates an edge-sensitive boosting factor to guide the gradient and Laplacian operator based edge detector of SRAD. The edge-sensitive boosting factor is defined by the global edge …

Util-Dss: Utilization-Based Dynamic Strategy Switching For Improvement In Data Centre Operation, Graham Foster

Electronic Thesis and Dissertation Repository

Applications are shifting into large scale, virtualized data centres that provide resources on a pay-per-usage basis. With power consumption representing a major operational cost, data centres must prioritize efficiency while still providing enough resources to meet application requirements. To meet variable application demands, a dynamic approach to virtual machine (VM) management is required. This requires: (i) placing newly arrived VMs, (ii) migrating VMs from highly utilized machines to avoid performance degradation, and (iii) migrating VMs from underutilized machines so that they may be deactivated to save power. Here, a management strategy is considered to be policy-set that guides these three …

Fuzzy Expert-Cocomo Risk Assessment And Effort Contingency Model In Software Project Management, Ekananta Manalif

Electronic Thesis and Dissertation Repository

Software development can be considered to be the most uncertain project when compared to other types of projects due to the uncertainty in the customer requirements, the complexity of the process, and the intangible nature of the product. In order to increase the likelihood of success in managing a software project, the project manager(s) must invest more time and effort in the project planning phase. The two main activities in project planning phase are effort estimation and risk management which has to be executed together because the accuracy of the effort estimation is highly dependent on the size and nature …

On The Physical Explanation For Quantum Computational Speedup, Michael Cuffaro

Electronic Thesis and Dissertation Repository

The aim of this dissertation is to clarify the debate over the explanation of quantum speedup and to submit, for the reader’s consideration, a tentative resolution to it. In particular, I argue that the physical explanation for quantum speedup is precisely the fact that the phenomenon of quantum entanglement enables a quantum computer to fully exploit the representational capacity of Hilbert space. This is impossible for classical systems, joint states of which must always be representable as product states. I begin the dissertation by considering, in Chapter 2, the most popular of the candidate physical explanations for quantum speedup: the …

Carbon Nitride And Conjugated Polymer Composite Materials, Josh Byers

Electronic Thesis and Dissertation Repository

The semiconductor and photovoltaic properties of carbon nitride (CNx) thin films prepared using a reactive magnetron sputtering technique were investigated both individually and as composites with the organic conjugated polymers polybithiophene (PBT) and poly(3-hextlthiophene) (P3HT). At low nitrogen content, the film structure was dominated by graphitic sp² percolation networks, whereas at higher nitrogen contents CNx films started to demonstrate semiconductor properties, as evidenced by the occurrence of photoconductivity and the development of a space charge region. When CNx was deposited onto a PBT substrate, it was found to function as an acceptor material improving the photocurrent generation both in …

A Multispectral Assessment Of Complex Impact Craters On The Lunar Farside, Bhairavi Shankar

Electronic Thesis and Dissertation Repository

Hypervelocity collisions of asteroids onto planetary bodies have catastrophic effects on the target rocks through the process of shock metamorphism. The resulting features, impact craters, are circular depressions with a sharp rim surrounded by an ejecta blanket of variably shocked rocks. With increasing impact energy, the inner crater cavity can preserve complex morphologies including terraced walls, central uplifts, and melted rocks. The lack of erosion due to the absence of water or an atmosphere makes the Moon the perfect target to study impact crater processes, in particular the distribution of highly shocked materials within impact craters of different sizes. …

Carboxylic Acid Functionalized Butyl Rubber: From Synthesis To Applications, Matthew John Mceachran

Electronic Thesis and Dissertation Repository

Butyl Rubber (RB) is a copolymer of isobutylene (IB) with small percentages of isoprene (IP). Typically these IP units serve as sites for the covalent cross-linking of the rubber, but they can also serve as sites to further functionalize RB. These modifications can expand the potential applications of RB. This thesis describes the synthesis of carboxylic acid functionalized RB and some properties and applications of these materials.

Persistence And Anti-Persistence: Theory And Software, Justin Quinn Veenstra

Electronic Thesis and Dissertation Repository

Persistent and anti-persistent time series processes show what is called hyperbolic decay. Such series play an important role in the study of many diverse areas such as geophysics and financial economics. They are also of theoretical interest. Fractional Gaussian noise (FGN) and fractionally-differeneced white noise are two widely known examples of time series models with hyperbolic decay. New closed form expressions are obtained for the spectral density functions of these models. Two lesser known time series models exhibiting hyperbolic decay are introduced and their basic properties are derived. A new algorithm for approximate likelihood estimation of the models using frequency …

Multi-Point Stride Coverage: A New Genre Of Test Coverage Criteria, Mohammad Mahdi Hassan

Electronic Thesis and Dissertation Repository

We introduce a family of coverage criteria, called Multi-Point Stride Coverage (MPSC). MPSC generalizes branch coverage to coverage of tuples of branches taken from the execution sequence of a program. We investigate its potential as a replacement for dataflow coverage, such as def-use coverage. We find that programs can be instrumented for MPSC easily, that the instrumentation usually incurs less overhead than that for def-use coverage, and that MPSC is comparable in usefulness to def-use in predicting test suite effectiveness. We also find that the space required to collect MPSC can be predicted from the number of branches in the …

Ph Responsive Hydrogen Bonding Motif To Improve The Sensitivity Of Tumor Imaging, Fatimah Mohammed Algarni

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) is a powerful non-invasive medical diagnostic technique. Superparamagnetic iron oxide nanoparticles (SPIO) are effective contrast agents and provide high sensitivity contrast in MRI. Recent research has demonstrated that nanoparticle clusters exhibit significantly higher relaxivity than individual nanoparticles.

In order to increase the sensitivity of tumor imaging, supramolecular chemistry was introduced to this field and a novel conjugation method was developed using click chemistry between azide functionalized nanoparticles and pH-sensitive hydrogen bonding building blocks. This pH-sensitive hydrogen bonded complex was synthesized to cluster nanoparticles under mildly acidic biological conditions.

Due to the unexpected X-ray crystal structure of …

A Support System For Graphics For Visually Impaired People, Hao Xu

Electronic Thesis and Dissertation Repository

As the Internet plays an important role in today’s society, graphics is widely used to present, convey and communicate information in many different areas. Complex information is often easier to understand and analyze by graphics. Even though graphics plays an important role, accessibility support is very limited for web graphics. Web graphics accessibility is not only for people with disabilities, but also for people who want to get and use information in ways different from the ones originally intended.

One of the problems regarding graphics for blind people is that we have few data on how a blind person draws …

Protein Structure And Interactions Studied By Electrospray Mass Spectrometry, Jiangjiang Liu

Electronic Thesis and Dissertation Repository

Since the emergence of electrospray ionization (ESI) mass spectrometry (MS) as a tool for protein structural studies, this area has experienced tremendous growth. ESI-MS is highly sensitive, and it allows the analysis of biological systems ranging in size from a few atoms to large multi-protein complexes. This work aims to solve questions in protein structural biology by using ESI-MS in conjunction with other techniques.

We initially apply ESI-MS for studying the monomeric protein cytochrome c (Chapter 2). The physical reasons underlying the irreversible thermal denaturation of this protein remain controversial. By utilizing deconvoluted charge state distributions, oxidative modifications were found …

The Periglacial Landscape Of Utopia Planitia; Geologic Evidence For Recent Climate Change On Mars., Mary C. Kerrigan

Electronic Thesis and Dissertation Repository

The northern plains of Utopia Planitia, Mars, hosts an abundance of potential periglacial landforms including scalloped depressions, gullies, and polygon networks. This research was undertaken to investigate the distribution and stratigraphy of scalloped depressions in Utopia Planitia and to reconstruct the past environment in which this periglacial landscape formed. To that end, a revised geologic map of the region has been produced. We define, for the first time, a new Periglacial Unit, the youngest geologic unit in Utopia Planitia. We have also developed a model for the formation and evolution of the periglacial landscape examined by assessing the use of …

X-Ray Absorption Fine Structure And X-Ray Excited Optical Luminescence Studies Of Gallium Nitride - Zinc Oxide Solid Solution Nanostructures, Matthew J. Ward

Electronic Thesis and Dissertation Repository

Gallium nitride – zinc oxide (GaN-ZnO) solid solutions have been realized as potential photocatalysts for overall water splitting due to a narrowing of the band-gap into the visible region of the solar spectrum. Although there has been much experimental and theoretical work on this novel class of semiconductors many questions about the nature of their electronic and chemical properties remain unanswered. In particular the mechanism of band-gap reduction in these materials is not clearly understood. It is also unclear what the local chemical environment of gallium, zinc, nitrogen, and oxygen is in both the surface and bulk of these solid …

The Study Of Optoelectronics In Semiconductor And Metallic Nanoparticle Hybrid Systems, Daniel G. Schindel

Electronic Thesis and Dissertation Repository

This thesis examines optoelectronics of photonic crystals and photonic nanofibers, especially with quantum dots and metallic nanoparticles doped into them. The simulations produced focus on the quantum dots, which are presented in an ensemble of 3-level systems.

In order to consider a photonic nanofiber in isolation, a model was developed for the density of photonic states. We studied two profiles, a square cross-section and a circular cross-section. In addition, we consider two architectures, one where a photonic crystal surrounds a dielectric fiber, and one where the fiber is another photonic crystal. We found several photonic nanofibers with a single bound …

A Study Of Gamma Radiation Induced Carbon Steel Corrosion, Kevin Daub

Electronic Thesis and Dissertation Repository

This thesis presents work on the development of a mechanistic understanding of the effect of ionizing radiation on the aqueous corrosion kinetics of carbon steel. Exposed to ionizing radiation, water decomposes into a range of oxidizing (O₂, •OH, HO₂•, H₂O₂) to reducing (•e_aq^–, •O₂^–, •H) species. The production of the redox active species by radiolysis can have a significant effect on the corrosion behaviour of a metal. Of particular interest is the effect of radiolysis on corrosion when the solution environment, such as temperature, pH, and …

Theory Of Model Kohn-Sham Potentials And Its Applications, Alex P. Gaiduk

Electronic Thesis and Dissertation Repository

The purpose of Kohn-Sham density functional theory is to develop increasingly accurate approximations to the exchange-correlation functional or to the corresponding potential. When one chooses to approximate the potential, the resulting model must be integrable, that is, a functional derivative of some density functional. Non-integrable potentials produce unphysical results such as energies that are not translationally or rotationally invariant. The thesis introduces methods for constructing integrable model potentials, developing properly invariant energy functionals from model potentials, and designing model potentials that yield accurate electronic excitation energies. Integrable potentials can be constructed using powerful analytic integrability conditions derived in this work. …

Estimating Subsurface Anisotropy: Combining Waveform Tomography And Simulated Annealing, Michael Victor Afanasiev

Electronic Thesis and Dissertation Repository

Crosshole seismic tomography has been used by Vale to provide geophysical images of mineralized massive sulphides in the Eastern Deeps deposit at Voisey's Bay. High resolution seismic images are presented by applying acoustic waveform tomography to these data. In waveform tomography, an initial model is required which predicts the first arrival traveltimes to within a half-cycle of the lowest frequency in the data. Because seismic velocity anisotropy can be significant, the initial model must quantify the anisotropy, as well as the velocity, in order to meet the half-cycle criterion.

In our case study, difficulties were encountered in generating an accurate …

Stable Isotopes And Xrd Investigation Of Gold Mineralization At The Syenite-Hosted Young-Davidson Deposit, Matachewan, Ontario, Niloufar Naderi

Electronic Thesis and Dissertation Repository

The Young-Davidson mine is a syenite-hosted orogenic gold deposit at the western end of the Cadillac-Larder-Lake deformation zone in the southern Abitibi greenstone belt, Canada. This study utilized oxygen isotopes to assess the sources of the fluids and evaluate the role of magmatic and metamorphic fluids in gold mineralization. XRD analyses completed on whole-rock powder samples combined with petrography provides a better understanding of the distribution, timing, and nature of alteration patterns and their relationship to gold mineralization.

Temperatures calculated from mineral separates oxygen isotope thermometry indicate the fluids ranged from approximately 322 ± 25° to 431 ± 30°C. The …