McGill University Thèses et mémoires par auteur commençant par B

We present a novel multi-model management method for numerical design optimization. The goal is to determine whether any of the analysis models associated with lower computational cost (that are typically expected to have inferior predictive capability relative to models associated with higher computational cost) can be used in certain areas of the design space as the latter is being explored during the optimization process. The framework quantifies and utilizes relative errors among available models regardless of their expected fidelity to enhance the predictive capability of inexpensive models and reduce the use of expensive ones. We implement our strategy by means …  Read more

Metallic plasmonic nanostructures continue to fascinate scientists and draw efforts into their smart design and assembly owing to their ability to enhance light manipulation and confinement in small volumes. Plasmonic interactions may be exploited in light-based photonic devices, where the miniaturization of photonic structures is essential to increase their sensitivity and speed. Common dielectric waveguides are restricted by the diffraction limit of light, which, for visible light, is several hundreds of nanometres. For nanodevices, much smaller photonic elements are sought through extended planar structures capable of light guiding. The flux of surface plasmons can be tuned and acclimatized for a …  Read more

Theoretical studies on the wetting of cylindrical solid surfaces with axisymmetric rugosities explicitly showed the presence of contact angle hysteresis, non-equilibrium jumps during contact line motion and the formation of composite surfaces. For physically rough surfaces with unidirectional randomness it was shown that hysteresis increases with decreasing roughness dimensions and with increasing standard deviation in the solid surface slope distribution. The wetting of solid surfaces by liquids was investigated by a new tensiometric technique called capillarography. At large roughness wavelengths ((TURN)100 (mu)m) the contribution of concentric sawtooth-shaped regular roughness was found to be close to the values calculated theoretically. At …  Read more

Designing a framework for realistic resolution-adaptive soil deformation on a large-scale terrain is a challenging problem for real-time applications. Capturing complex behaviors of the soil requires computationally expensive deformation models. In addition, terrain compression techniques are required to tackle the memory limitations in a large-scale simulation. In this thesis, we use a finite element soil deformation model with an adjustable resolution. We apply approximations to calculate the internal forces of the deformation model and we present a simple elastoplasticity model. We find that using a constant incomplete Cholesky preconditioner (factorized in the initial time-step) can greatly reduce the convergence time …  Read more

This study was initiated to determine the effects of Herring Gulls (Larus argentatus) on the vegetation and soils of their nesting sites within the Mingan Island National Park Reserve. Both vegetation (species composition, cover, density, growth) and soil characteristics (pH, N, P, K, Ca, Mg) were monitored throughout the 1995 breeding season. Exclosures were installed within the colonies as control sites to prevent gull activity and these were compared to "treatment plots" or areas where gulls were present. All plants located at the study sites were native perennials with the exception of Stellaria, a native annual. Ledum groenlandicum was the …  Read more

Monte Carlo (MC) dose calculations cannot accurately assess the dose delivered to the patient during radiotherapy unless the patient anatomy is well known. This thesis focuses on the conversion of patient computed tomography (CT) images into MC geometry files. Metal streaking artifacts and their effect on MC dose calculations are first studied. A correction algorithm is applied to artifact-corrupted images and dose errors due to density and tissue mis-assignment are quantified in a phantom and a patient study. The correction algorithm and MC dose calculations for various treatment beams are also investigated using phantoms with real hip prostheses. As a …  Read more

Bovine soluble lens protein was fractionated by a variety of Chromatographic procedures. Bio-Gel A-1.5 M gave a reproducible elution profile consisting of 5 fractions, designated l -> V. The physicochemical properties and degree of heterogeneity of the fractions were studied in dissociating and/or non dissociating solvents by the following methods: ion-exchange chromatography on DEAE-cellulose, sedimentation velocity, high-speed meniscus depletion sedimentation equilibrium, polyacrylamide gel electrophoresis, immuno-diffusion, determination of spectral quantities, amino acid analysis and sulfhydryl group estimation. Comparison of the data with the literature suggestion that Fractions I, II and III, IV, and V were a-, β-, βs- and γ-crystallin respectively. …  Read more

This dissertation consists of three chapters that contribute to the study of blended learning and academic performance. The importance of STEM education is well documented in the literature; however, many educators and researchers have expressed major concern regarding the present state of STEM education. To improve this situation, new pedagogies, such as blended learning have been proposed and researched. The last decade has seen an increase in the use of blended learning to support student learning and enhance engagement in STEM education; however, the effect of blended learning on teaching and learning remains unclear and often are mixed. The extant …  Read more

Les précipitations acides dues aux émissions industrielles de dioxyde de soufre et d'oxyde d'azote ont causé des dommages écologiques dans plusieurs milieux aquatiques en Amérique du Nord et dans le nord de l’Europe. À ce titre, les communautés aquatiques exposées aux retombées acides constituent certains des cas les plus étudiés de la réponse d’un écosystème entier face à un facteur de stress. Le déclin des organismes sensibles à l'acide et l'augmentation concomitante des organismes plus résistants est une réponse fréquente; s’installe ainsi une communauté biologique différente de l’originale. Cependant, à la suite de décennies d'exposition à des eaux acides, il …  Read more

Cystic fibrosis (CF) is a severe, systemic disease that impacts multiple organs, including the lungs, bones and intestine. In the lungs, in addition to reoccurring cycles of infection and inflammation, a subset of CF patients present with airway hyperresponsiveness, the increased response of the airways to stimulus. In the intestine, CF patients present with obstructions, small intestinal bacterial overgrowth and an altered intestinal microbiome. In this thesis, we used CF mouse models, which recreate many of the CF clinical phenotypes, to investigate components of the CF disease, including the airway mechanics, intestinal disease and the intestinal microbiome. As dysbiosis of …  Read more

Huebner, Steven (Supervisor1)  Read more

L'accès aux informations visuelles sur internet demeure un obstacle majeur pour les personnes aveugles ou malvoyantes, en particulier concernant les visualisations de données telles que les graphiques. Cette thèse explore comment les récents progrès en intelligence artificielle peuvent améliorer l'accessibilité grâce à des innovations dans la synthèse de graphiques, un processus d'extraction automatique d'informations à partir d'un graphique et de compilation en un résumé textuel intelligible pour les lecteurs d'écran.La thèse se concentre sur deux principaux axes de recherche. Premièrement, elle applique l'architecture émergente des agents basés sur les grands modèles de langage à la tâche de synthèse de graphiques, …  Read more

Mercier, Francois (Supervisor1)  Read more

Pierre Attaingnant's fourteen-volume Motet Series (1534-1539) was a monumental achievement in music printing, featuring innovative approaches to organisation and far exceeding the four earlier motet series printed by Petrucci, Antico, and Moderne, in terms of size and structure. Part I of my dissertation provides a historical context for the Series. Chapter 1 reviews the early years of François I's reign, the musical establishments at the court, and the King's own interest in music. Chapter 2 outlines the state of the motet in sixteenth-century France, and the beginnings of music printing. I then compare the four "predecessors" to Attaingnant's Series in …  Read more

Inflationary cosmology is the standard paradigm of early universe physics. Inflation leaves the universe in a non-thermal state, very cold and effectively empty of matter. Hence any successful inflationary model must explain how the inflationary phase is connected to the high temperatures at Big Bang Nucleosynthesis as well as explaining the production of the Standard Model particles. The Reheating mechanism has been introduced to inflationary cosmology in order to explain transfer ofenergy which is stored in the inflaton field to other dynamical degrees of freedom in the universe and render the universe hot. Therefore, reheating is an integral part of …  Read more

Several systems, containing up to 10 mol % ionic co-units, were investigated by dynamic mechanical techniques, primarily above the glass transition. The ionic units in quaternized poly(styrene-co-4-vinylpyridine) mildly retard chain diffusion. In contrast, the rubbery plateau of blends of poly(styrene-co-styrene-sulfonic acid) and poly(ethyl acrylate-co-4-vinylpyridine), compatible above ca. 4 mol % co-unit content, is greatly extended, independent of co-unit content. It is postulated that the kinetics of ion dissociation and reassociation in the blends are faster than chain diffusion, effectively trapping chain entanglements for comparatively long times. Time-temperature reducibility applies to both the cationic ionomers and the blends. It fails at …  Read more

We have used the living ring-opening metathesis polymerization (ROMP) reaction with C12(PCy3)2Ru=CHPh to generate a new class of conjugated polymer precursors containing the reactive group 1,2-dichlorocarbonate in their backbone. These polymers possess narrow molecular weight distributions and are easily processable. We have incorporated the 1,2-dichlorocarbonate monomers into block copolymers and have shown that these systems can self-assemble in selective solvents to generate spherical micellar aggregates, as observed by transmission electron microscopy (TEM). Mild hydrolytic treatment of these precursor polymers converts them into novel low band-gap conjugated polymers and block copolymers containing 1,2-diol groups in their backbone. We then report the …  Read more

Japan Day by Day---the Western Zoologist Edward S. Morse's account of his stay in Japan from 1877 to 1883---is analyzed by first comparing it to other contemporary travelogues written by western travelers to Japan, and then by viewing it through a more theoretical framework, including Edward Said's theory on post-colonialism and Michel Foucault's theory of discourse and body experiences. Viewed through this framework, the goal of analysis is not to test the validity of Morse's writings, but to explore the formation of his interpretation of his experience in Japan.  Read more

Kostikov, Alexey (Supervisor2)  Read more

Fiber Reinforced polymer composite materials offer great potential for waterfront structural applications due to their excellent corrosion resistance, and high strength to weight ratio. The purpose of this thesis is to develop a deflection based design approach for composite sheet pile wall, based on the traditional free-earth support method, but modified to allow the use of deflection criterion. With a simplified earth pressure loading on the wall, the relationship between maximum bending moment and maximum bending deflection and the relationship between maximum shear force and maximum shear deflection were established. 16 case studies were carried out to include walls ranging …  Read more

In recent years a number of studies have revealed the existence of biochemical differences between the body fluids of schizophrenic patients and the body fluids of normal human subjects. In particular, differences have been reported in both urine constituents and blood constituents; and in blood constituents, not only in the plasma fraction, but also in the formed elements (or cells) fraction. While the nature of the association between such biochemical anomalies and the behavioral anomalies of schizophrenic patients remains to be investigated, evidence is accumulating that a factor, or factors in the blood substances of schizophrenic patients can disrupt the …  Read more

Man has been aware of the analgesic and narcotic effects of opium, the dried juice of the poppy, at least since civilization dawned in Egypt. However, it was an impure substance and its effects were unpredictable: it might cure pain, provide a "boost", or kill. Not until the Sixteenth Century did man start to unravel the secret of opium. [...]  Read more

Voluntary consumption, as a criterion of feeding value of two forage species was further tested by determining the “within species” effect of stage of maturity and of the physical form in which these forages were fed. Chemical composition, digestibility coefficients, voluntary intake and liveweight gains were determined. Various relationships between these factors and their relationship to forage species, stage of maturity and to the physical form in which the forage was fed, were investigated. Voluntary intake of the forages (including the effect of species, stage of maturity and physical form) was highly and significantly correlated to feeding value, whether expressed …  Read more

[...] DESCRIPTION. The Gray horizontal engine is of the 4 Cycle single acting type and has a single cylinder. It is fitted with a reciprocating fuel pump, which forces the gasoline into the ordinary type or jet carburettor. The pump action is determined by a shaft governor, which has a range of from 200 to 400 R.P.M's., but is very erratic at the lower speeds. When the speed rises above that for which the governor is set, the exhaust valve is held open, and the automatic inlet valve remains closed and by a system of levers, the pump is prevented …  Read more

The effects of interference and channel noise make reliable communication a challenging problem. Most existing multiuser communication systems still perform far below their theoretical limits, partly because the implementation of optimal multiuser receivers has exponential complexity. This thesis studies aspects of transmission over the multi-access (MAC) channel in case of K equal power users. It is motivated by wireless communication systems with perfect power control and optical transmission in local area networks. Limits on CDMA transmission are obtained using multi-access channel models and capacity calculations. Using these insights, a technique is proposed to increase throughput over MAC channels by exploiting …  Read more

Crowley, David (Supervisor)  Read more

All geological processes taking place at the surface of the earth are either influenced or caused by the energy relations between the sun, the surface of the earth, and the atmosphere. Since the surface and atmosphere, unlike the sun, cannot be divorced from the effects of surface geological processes, it follows that these processes, in turn, affect the energy relations between the earth and atmosphere. In short, there is a relationship between geological and atmospheric phenomena which is of utmost importance in both geology and paleoclimatology.  Read more

Over the past 30 years the transportation of goods has developed beyond recognition. The transportation infrastructure is sophisticated and relatively efficient and it is not unusual for goods to be shipped by more than one mode of transportation. Unfortunately, private law has not kept pace with these infrastructure changes. Therefore, a different liability regime applies to every unimodal type of transportation. Though, each unimodal regime is usually based on similar principles they are sufficiently different, from each other, to create a great deal of uncertainty when trying to assess the liability of the participants, in the transportation venture. Such uncertainly …  Read more

Des millions de barrières anthropiques obstruent les rivières du monde et renferment des réservoirs (Lehner et al. 2011a). La hauteur et le volume de réservoir de ces barrières varient grandement, tout comme les rivières sur lesquelles elles sont situées. Bien qu'initialement construites dans le but de protéger les terres et les populations environnantes contre les inondations et de les approvisionner en hydroélectricité et en eau pour l'irrigation, les barrières fluviales ont également des conséquences socio-environnementales imprévues et néfastes. En plus de perturber la migration des poissons, les barrières fluviales et leurs réservoirs peuvent forcer le déplacement de communautés humaines et …  Read more

Moxley, J. E.  Read more

Les signaux moléculaires qui guident la croissance axonale comme nétrine-1 sont connus pour être importants au développement des circuits neuronaux, mais peu est connu sur leurs rôles possibles à l'âge adulte. Le travail récent de notre laboratoire démontre que le récepteur de nétrine-1 « deleted in colorectal cancer » (DCC) régule la structure et le fonctionnement des synapses matures dans le cerveau des mammifères. Ici, nous démontrons que la protéine nétrine-1 est facilement détectable dans le cerveau adulte et est nécessaire pour la potentialisation à long terme (PLT) de la synapse hippocampale des collatérales de Schaffer. Ensuite, à l’aide d’approches …  Read more

Alters, Brian Josiah (Internal/Cosupervisor2)  Read more

Stix, John (Supervisor2)  Read more

Today's Web browsers provide a platform for the development of complex, richly interactive user interfaces. But, with this complexity come additional challenges for Web developers. The complicated behavioural relationships between user interface components are often stateful, and are difficult to describe, encode and maintain using conventional programming techniques with ECMAScript, the general-purpose scripting language embedded in all Web browsers. Furthermore, user interfaces must be performant, reacting to user input quickly; if the system responds too slowly, the result is a visible UI "lag," degrading the user's experience. Statecharts, a visual modelling language created in the 1980's for developing safety-critical embedded …  Read more

In recent years the overwhelming revolutionary biological discoveries and techniques have introduced an awareness of moral, ethical, and philosophical concepts in the social consciousness.  Read more

We have carried out large scale Monte Carlo simulations of site and bond frustrated Heisenberg models in order to gain insight into experimental phase diagrams on bond and site frustrated magnetic materials. In the case of site frustrated models, we find that spin glass ordering does not take place on either the simple cubic or body-centered cubic lattices which are bipartite. Instead, the model decouples into either one or two percolating clusters of ferromagnetic (antiferromagnetic) sites which order ferromagnetically (antiferromagnetically). The ordering is similar to the situation which exists when ferromagnetic and antiferromagnetic sites do not interact at all. Including …  Read more

This study focuses on understanding the photochemical reactions that occur between ultraviolet stabilizers and lignin during irradiation in order to further comprehend the photo-protection mechanisms of these stabilizers during brightness reversion. The stabilizers chosen for study included a variety of ultraviolet absorbers (UVAs), in addition to a hindered nitroxide free radical (4-hydroxy-TEMPO). Irradiated samples were analyzed using quantitative 31P NMR, in addition to a technique known as 'Derivatization Followed by Reductive Cleavage'. Benzophenone-based UVAs have been shown to be actively involved in photochemical reactions with lignin during irradiation, while benzotriazole-based UVAs are comparatively photostable under identical irradiation techniques. All additive …  Read more

Cette thèse développe des méthodes de calcul pour la conception et l'évaluation de barres idiophones, avec un accent mis sur les marimbas et les vibraphones. Les méthodes développées utilisent des modèles informatiques pour permettre l'évaluation de nouvelles conceptions de barres et de nouveaux matériaux, réduisant ou retardant le besoin de prototypes physiques. Les principaux apports de ce travail portent à la fois sur les méthodes de conception et sur les méthodes d’évaluation.L'accord traditionnel des barres de marimba consiste à tailler un “cutaway” ou un “undercut” au bas de la barre pour ajuster les fréquences jusqu'à trois modes de flexion de …  Read more

We first give a modern presentation of the formal language of Frege's Grundgesetze. There follows a comparison of the motivations for Frege's "Cumulative Type Theory" and for Russell's Type Theory and of the basic arithmetical definitions in each. Quine's New Foundations and, in particular, extensions of Jensen's modification, NFU, are introduced and consistency results are discussed. Finally, an interpretation is given in an NFU framework of a modified form of the Grundgesetze theory. It is shown that an "Axiom of Counting" necessary for arithmetic in NFU is needed in an analogous way for arithmetic in our interpretation; it is further …  Read more

Rousseau, Cecile (Internal/Supervisor)  Read more