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Consequences of Insect Flight Loss for Molecular Evolutionary Rates and DiversificationMitterboeck, T. Fatima 25 May 2012 (has links)
This thesis investigates the molecular evolutionary and macroevolutionary consequences of flight loss in insects. Chapter 2 tests the hypothesis that flightless groups have smaller effective population sizes than related flighted groups, expected to result in a consistent pattern of increased non-synonymous to synonymous ratios in flightless lineages due to the greater effect of genetic drift in smaller populations. Chapter 3 tests the hypothesis that reduced dispersal and species-level traits such as range size associated with flightlessness increase extinction rates, which over the long term will counteract increased speciation rates in flightless lineages, leading to lower net diversification. The wide-spread loss of flight in insects has led to increased molecular evolutionary rates and is associated with decreased long-term net diversification. I demonstrate that the fundamental trait of dispersal ability has shaped two forms of diversity—molecular and species—in the largest group of animals, and that microevolutionary and macroevolutionary patterns do not necessarily mirror each other. / Generously funded by NSERC with a Canada Graduate Scholarship and the Government of Ontario with an Ontario Graduate Scholarship to T. Fatima Mitterboeck; NSERC with a Discovery Grant to Dr. Sarah J. Adamowicz
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Les lotissements d'Orléans et la formation d'une périphérie urbaine (1875-1958) : processus d'extension, formes et règlements / The subdivisions of Orleans' city and the urbanization of the outskirts (1875-1958) : mecanism of urban extension, forms and regulationsLaunay, Yann 29 September 2015 (has links)
La formation de la périphérie urbaine d’Orléans des années 1870 à l’après-guerre, étudiée à partir d’une échelle d’analyse particulière, le lotissement, constitue le sujet central de cette thèse. L’analyse des processus d’extension resitue plus largement les lotissements dans la ville. Elle montre d’abord les relations étroites qu’ils entretiennent avec le quartier Dunois, aménagé en 1879-1880. Si les Plans d’aménagement, d’embellissement et d’extension (loi Cornudet, 1919), ont peu d’impact sur la construction des lotissements, ces derniers témoignent, à des degrés divers, de la mise en oeuvre du Projet de reconstruction et d’aménagement de la commune (1949). La compréhension du cadre réglementaire et juridique permet d’éclairer la politique d’aménagement de voirie municipale et les projets de lotissement sur une longue durée. Elle nous renseigne également sur la constitution du paysage urbain. Cette étude offre ainsi de nouvelles clés de lecture du territoire orléanais, en nous informant non seulement sur les acteurs et leurs pratiques, mais également sur les formes urbaines et architecturales que ces hommes ont générées / This dissertation focuses on the urbanization of Orléans’ (France) outskirts, from the 1870s to the post-war period, studied from a special analysis of scale, i.e. subdivisions. Analysis of mechanisms and forms of urban extension situates subdivisions in the city on a wider scale. It first enhances the close relationship that subdivisions have with the quartier Dunois that was planned in 1879-1880. In 1919, a French town-planning law named “Cornudet Act” was established. It appears that it had little impact on the construction of subdivisions. In fact, it is the implementation of town-planning for reconstruction and rehabilitation in 1949 that showed more its influence on the construction of subdivisions. Understanding the regulatory and legal framework can illuminate road system rehabilitation policy of the city and subdivision projects on a long-term perspective. It highlights the creation of urban landscape as well. This study provides new keys to understand Orléans’ territory: not only does it accounts for the actors’ roles and their practices, but it also provides new insights into urban and architectural forms that these people generated.
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Habitat périurbain autoconstruit en République démocratique du Congo: perspectives d'amélioration des logements de terre crue en climat tropicalChirhalwirwa, Liévin 26 September 2008 (has links)
Les difficultés d’accès à un logement décent, le coût exorbitant des matériaux de construction dits « nobles » ainsi que l’absence des filières de production foncière et immobilière en RDCONGO ont motivé cette recherche orientée vers l’utilisation des matériaux locaux – et en particulier la terre crue – en vue de contribuer à la résorption des problèmes d’habitat auxquels font face la plupart des populations vivant en zone périurbaine congolaise.<p><p>Cette thèse démontre qu’il est possible, à travers l’autoconstruction – procédé utilisé par plus de 80% de ménages congolais pour produire leurs logements – ,d’améliorer l’habitat dans ce pays en partant de la zone périurbaine. On peut donc, à partir des propositions faites dans cet espace idéalement localisé entre les zones urbaine et rurale, envisager des répercutions positives au sein de ces deux zones qui lui sont contiguës.<p><p>L’observation constitue la principale méthodologie utilisée. <p>Des enquêtes menées sur quelques 930 logements situés au sein de trois sous zones climatiques de la RDCONGO ont permis, suivant 29 critères principaux appliqués sur 3 différents paliers (la maison, la parcelle et le quartier) d’engranger plus de 100 000 (cent mille) données reprises dans les annexes à la présente et offrant la possibilité d’extrapoler les résultats obtenus sur l’ensemble du territoire de la RDCONGO.<p><p>Inventaire des intelligences et connaissances locales relatives à l’utilisation du matériau terre en construction (Savoirs et Pratiques Populaires « SPP »), espaces engendrés par les architectures de terre en RDCONGO, cartographies des constructions en terre en RDCONGO, maisons périurbaines autoconstruites en adobes, modélisation d’un lotissement de 200 logements réalisables en terre crue, etc. constituent les principaux résultats atteints par cette thèse.<p><p>Toutefois, il sied de préciser qu’il s’agit ici, non seulement de construire des maisons en terre, mais surtout de développer un style d’habitat répondant à la fonctionnalité des logements et susceptible de renforcer les dimensions sociales et culturelles tout en respectant l’environnement. <p><p>Enfin, des pistes de recherches ultérieures sont envisagées. Elles nécessitent d’être creusées en vue d’autres améliorations des logements de terre crue en climat tropical. <p>Il s’agit de :l’érosion due au ruissellement sur les murs de terre, l’étude des logements de terre crue en hauteur (R+1, 2, 3, …n ;où n représente le nombre d’étages) pour la RDCONGO, le développement des activités économiques liées aux constructions en terre, la stabilisation organique des sols à l’aide des produits locaux, etc.<p><p><p><p>Contact :arch2002chiral@yahoo.fr<p> / Doctorat en Art de bâtir et urbanisme / info:eu-repo/semantics/nonPublished
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An empirically derived system for high-speed renderingRautenbach, Helperus Ritzema 25 September 2012 (has links)
This thesis focuses on 3D computer graphics and the continuous maximisation of rendering quality and performance. Its main focus is the critical analysis of numerous real-time rendering algorithms and the construction of an empirically derived system for the high-speed rendering of shader-based special effects, lighting effects, shadows, reflection and refraction, post-processing effects and the processing of physics. This critical analysis allows us to assess the relationship between rendering quality and performance. It also allows for the isolation of key algorithmic weaknesses and possible bottleneck areas. Using this performance data, gathered during the analysis of various rendering algorithms, we are able to define a selection engine to control the real-time cycling of rendering algorithms and special effects groupings based on environmental conditions. Furthermore, as a proof of concept, to balance Central Processing Unit (CPU) and Graphic Processing Unit (GPU) load for and increased speed of execution, our selection system unifies the GPU and CPU as a single computational unit for physics processing and environmental mapping. This parallel computing system enables the CPU to process cube mapping computations while the GPU can be tasked with calculations traditionally handled solely by the CPU. All analysed and benchmarked algorithms were implemented as part of a modular rendering engine. This engine offers conventional first-person perspective input control, mesh loading and support for shader model 4.0 shaders (via Microsoft’s High Level Shader Language) for effects such as high dynamic range rendering (HDR), dynamic ambient lighting, volumetric fog, specular reflections, reflective and refractive water, realistic physics, particle effects, etc. The test engine also supports the dynamic placement, movement and elimination of light sources, meshes and spatial geometry. Critical analysis was performed via scripted camera movement and object and light source additions – done not only to ensure consistent testing, but also to ease future validation and replication of results. This provided us with a scalable interactive testing environment as well as a complete solution for the rendering of computationally intensive 3D environments. As a full-fledged game engine, our rendering engine is amenable to first- and third-person shooter games, role playing games and 3D immersive environments. Evaluation criteria (identified to access the relationship between rendering quality and performance), as mentioned, allows us to effectively cycle algorithms based on empirical results and to distribute specific processing (cube mapping and physics processing) between the CPU and GPU, a unification that ensures the following: nearby effects are always of high-quality (where computational resources are available), distant effects are, under certain conditions, rendered at a lower quality and the frames per second rendering performance is always maximised. The implication of our work is clear: unifying the CPU and GPU and dynamically cycling through the most appropriate algorithms based on ever-changing environmental conditions allow for maximised rendering quality and performance and shows that it is possible to render high-quality visual effects with realism, without overburdening scarce computational resources. Immersive rendering approaches used in conjunction with AI subsystems, game networking and logic, physics processing and other special effects (such as post-processing shader effects) are immensely processor intensive and can only be successfully implemented on high-end hardware. Only by cycling and distributing algorithms based on environmental conditions and through the exploitation of algorithmic strengths can high-quality real-time special effects and highly accurate calculations become as common as texture mapping. Furthermore, in a gaming context, players often spend an inordinate amount of time fine-tuning their graphics settings to achieve the perfect balance between rendering quality and frames-per-second performance. Using this system, however, ensures that performance vs. quality is always optimised, not only for the game as a whole but also for the current scene being rendered – some scenes might, for example, require more computational power than others, resulting in noticeable slowdowns, slowdowns not experienced thanks to our system’s dynamic cycling of rendering algorithms and its proof of concept unification of the CPU and GPU. / Thesis (PhD)--University of Pretoria, 2012. / Computer Science / unrestricted
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Photon tracing na GPU / Photon Tracing on GPUGalacz, Roman January 2013 (has links)
Subject of this thesis is acceleration of the photon mapping method on a graphic card. The photon mapping is a method for computing almost realistic global illumination of the scene. The computation itself is relatively time-consuming, so the acceleration of it is a hot issue in the field of computer graphics. The photon mapping is described in detail from photon tracing to rendering of the scene. The thesis is then focused on spatial subdivision structures, especially to the uniform grid. The design and the implementation of the application computing the photon mapping on GPU, which is achieved by OpenGL and CUDA interoperability, is described in the next part of the thesis. Lastly, the application is tested properly. The achieved results are reviewed in the conclusion of the thesis.
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Procedurálně generované město / Procedurally Generated CityPanáček, Petr January 2011 (has links)
This paper deals with problem of procedurally generated city. There are described steps of creation of city. These steps are: road generation, extraction of minimal cycles in graph, division of lots and generation of buildings. Road and buildings are generated by L-system. Our system generate a city from input images, such as height map, map of population density and map of water areas. Proposed approaches are used for implementation of application for generation of city.
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Minimalistická reprezentace modelu areálu Božetěchova / Minimal Representation of the Božetěchova ComplexKrál, Tomáš Unknown Date (has links)
The document describes developing graphical application with limited size. It describes suitable techniques for a polygonal mesh's compression. The second part is focused on practical usage of this techniques for developing scene in 3D modeling environment and also describes how to transfer this model to the executable file. The work attends to optimalizations of source code compilation and executables compression at the final chapters.
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Problèmes d'économétrie en macroéconomie et en finance : mesures de causalité, asymétrie de la volatilité et risque financierTaamouti, Abderrahim January 2007 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
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