This thesis aims to seek interesting patterns from massive amounts of Flickr data in Sweden with pro- posed new clustering strategies. The aim can be further divided into three objectives. The first one is to acquire large amount of timestamped geolocation data from Flickr servers. The second objective is to develop effective and efficient methods to process the data. More specifically, the methods to be developed are bifold, namely, the preprocessing method to solve the “Big Data” issue encountered in the study and the new clustering method to extract spatio-temporal patterns from data. The third one is to analyze the extracted patterns with scaling analysis techniques in order to interpret human social activities underlying the Flickr Data within the urban envrionment of Sweden. During the study, the three objectives were achieved sequentially. The data employed for this study was vector points downloaded through Flickr Application Programming Interface (API). After data ac- quisition, preprocessing was performed on the raw data. The whole dataset was firstly separated by year based on the temporal information. Then data of each year was accumulated with its former year(s) so that the evovling process can be explored. After that, large datasets were splitted into small pieces and each piece was clipped, georeferenced, and rectified respectively. Then the pieces were merged together for clustering. With respect to clustering, the strategy was developed based on the Delaunay Triangula- tion (DT) and head/tail break rule. After that, the generated clusters were analyzed with scaling analysis techniques and spatio-temporal patterns were interpreted from the analysis results. It has been found that the spatial pattern of the human social activities in the urban environment of Sweden generally follows the power-law distribution and the cities defined by human social activities are evolving as time goes by. To conclude, the contributions of this research are threefold and fulfill the objectives of this study, respectively. Firstly, large amount of Flickr data is acquired and collated as a contribution to other aca- demic researches related to Flickr. Secondly, the clustering strategy based on the DT and head/tail break rule is proposed for spatio-temporal pattern seeking. Thirdly, the evolving of the cities in terms of human activities in Sweden is detected from the perspective of scaling. Future work is expected in major two aspects, namely, data and data processing. For the data aspect, the downloaded Flickr data is expected to be employed by other studies, especially those closely related to human social activities within urban environment. For the processing aspect, new algorithms are expected to either accelerate the processing process or better fit machines with super computing capacities.

Master of Arts / Department of Communications Studies / Timothy Steffensmeier / Due to a rising interest for degrees in higher education, more students with disabilities have enrolled in the university system. Still, accessibility issues on campuses suggest institutions are not meeting the needs of students in the classroom or through curricula. This study examines current academic adjustments and the lived experiences of students with disabilities in order to understand the ableist Othering phenomenon in higher education. Qualitative research methods have been commonly used to investigate the “disabled voice”; however, triangulation of such methodologies has been criticized for reinforcing Otherness. This study used a phenomenological design implementing rhetorical agency for disabled students to answer open-ended questions in semi-structured interviews about their lived experiences. Consequently, such interviews created a platform for social change. The author also reflects on his own lived experiences as a deaf student in higher education. Findings include major themes such as a percolation of institutional hegemony, a re-appropriation of stigma through “voice,” and a call for inclusive strategies. Results indicate disabled students experience discrimination likely due to organizational tension in their university institution. Further, this study elaborates on proposed policy changes to college classrooms on large university campuses. Contributions of this study lie in implications for the future of qualitative inquiry, including how current research practices could undergo methodological reinvention to examine the ableist Othering phenomenon.

Master of Science / Department of Electrical and Computer Engineering / Christopher L. Lewis / This thesis describes the development of an automated computer vision system that identifies and inventories road signs from imagery acquired from the Kansas Department of Transportation's road profiling system that takes images every 26.4 feet on highways through out the state. Statistical models characterizing the typical size, color, and physical location of signs are used to help identify signs from the imagery. First, two phases of a computationally efficient K-Means clustering algorithm are applied to the images to achieve over-segmentation. The novel second phase ensures over-segmentation without excessive computation. Extremely large and very small segments are rejected. The remaining segments are then classified based on color. Finally, the frame to frame trajectories of sign colored segments are analyzed using triangulation and Bundle adjustment to determine their physical location relative to the road video log system. Objects having the appropriate color, and physical placement are entered into a sign database. To develop the statistical models used for classification, a representative set of images was segmented and manually labeled determining the joint probabilistic models characterizing the color and location typical to that of road signs. Receiver Operating Characteristic curves were generated and analyzed to adjust the thresholds for the class identification. This system was tested and its performance characteristics are presented.

Ce projet de maîtrise présente l'intégration d'une méthode d'optimisation topologique dans le processus de Conception et Fabrication Assistée par Ordinateur. Il fut réalisé dans le cadre d'un projet multidisciplinaire issu d'une collaboration entre le groupe de recherche en optimisation des structures de l'Université de Sherbrooke (OptiS) et l'Équipe de Recherche en Intégration CAO-Calcul de l'UQTR (ÉRICCA).Ce projet multidisciplinaire consiste à développer un gratuiciel multiplateforme d'optimisation des structures intégrant la CAO à l'optimisation afin de permettre le développement complet de pièces ou structures mécaniques en partant du modèle CAO initial, jusqu'au modèle CAO final optimisé. Deux objectifs principaux sont visés dans le cadre de ce projet de maîtrise. Premièrement, implanter la méthode d'optimisation topologique par homogénéisation (méthode SIMP) pour des structures quelconques en 3D. Deuxièmement, développer une méthode de lissage pour réduire le bruit présent sur le maillage optimisé résultant de l'optimisation topologique par la méthode SIMP. Nous avons atteint ces deux objectifs en développant un processus d'optimisation complètement automatique en sept étapes. Elles correspondent respectivement à la modélisation géométrique, l'entrée des données initiales du problème (conditions aux limites, matériau, etc.), la sous-division de la géométrie en sous-domaines de design et de non-design, le maillage automatique adapté aux sous-domaines multiples, l'optimisation topologique, le lissage du maillage de surface et finalement la reconstruction de la géométrie finale. Les résultats ont démontré que notre implantation de la méthode SIMP fonctionne et donne des résultats très intéressants qui s'apparentent aux résultats présentés dans la littérature. Néanmoins, le développement d'une méthode de lissage de triangulation basée sur les méthodes classiques a démontré que ces méthodes sont très mal adaptées à des maillages très bruités tels que ceux obtenus avec la méthode SIMP. En somme, ce projet a permis de faire un grand pas vers l'intégration complète de l'optimisation comme une étape à part entière du processus de CAO/FAO.

In this thesis, an approach is presented for the generation of grids suitable for the simulation of high Reynolds number viscous flows in complex three-dimensional geometries. The automatic and reliable generation of such grids is today on the biggest bottlenecks in the industrial CFD simulation environment. In the proposed approach, unstructured tetrahedral grids are employed for the regions far from the viscous boundaries of the domain, while semi-structured layers of high aspect ratio prismatic and hexahedral elements are used to provide the necessary grid resolution inside the boundary layers and normal to the viscous walls. The definition of the domain model is based on the STEP ISO standard and the topological information contained in the model is used for applying the hierarchical grid generation parameters defined by the user. An efficient, high-quality and robust algorithm is presented for the generation of the unstructured simplicial (triangular of tetrahedral) part of the grid. The algorithm is based on the Delaunay triangulation and the internal grid points are created following a centroid or frontal approach. For the surface grid generation, a hybrid approach is also proposed similar to the volume. Semi-structured grids are generated on the surface grid (both on the edges and faces of the domain) to improve the grid resolution around convex and concave ridges and corners, by aligning the grid elements in the directions of high solution gradients along the surface. A method is also developed for automatically setting the grid generation parameters related to the surface grid generation based on the curvature of the surface in order to obtain an accurate and smooth surface grid. Finally, a semi-structured prismatic/hexahedral grid generation algorithm is presented for the generation of the part of grid close to the viscous walls of the domain. The algorithm is further extended with improvements meant to increase the grid quality around concave and convex ridges of the domain, where the semi-structured grids are known to be inadequate. The combined methodology is demonstrated on a variety of complex examples mainly from the automotive and aeronautical industry.

本篇文章是針對「凸多邊形的三角化」和「正方形街道中，好路徑的方法」(正方形街道中走 步 向右， 步 向上，且沿途中 不超過 的捷徑走法)兩者之間的對應關係的探討。

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The main results of this dissertation show evidence supporting the Successive Surface Scaffolding Conjecture. This is a new conjecture that, if true, guarantees the existence of all the wye-delta-order minimal obstructions of a surface S as subgraphs of the irreducible triangulations of the surface S with a crosscap added. A new data structure, i.e. an augmented rotation system, is presented and used to create an exponential-time algorithm for embedding graphs in any surface with a constant-time check of the change in genus when inserting an edge. A depiction is a new formal definition for representing an embedding graphically, and it is shown that more than one depiction can be given for nonplanar embeddings, and that sometimes two depictions for the same embedding can be drastically different from each other. An algorithm for finding the essential cycles of an embedding is given, and is used to confirm for the projective-plane obstructions, a theorem that shows any embedding of an obstruction must have every edge in an essential cycle. Obstructions of a general surface S that are minor-minimal and not double-wye-delta-minimal are shown to each have an embedding on the surface S with a crosscap added. Finally, open questions for further research are presented. / Graduate

This qualitative descriptive case study investigates four Chinese international students’ use of online resources for academic writing in a western Canadian university. This study has direct implications for English as a Foreign Language/English as a Second Language writing instruction as well as international students’ use of university library. Methodological triangulation was used to collect data. This included a semi-structured interview, a computer-based writing task, and a think-aloud activity. Data was coded and analyzed within cases and re-analyzed across the four cases. The salient themes that emerged from this analysis include: indispensable role of online resources in academic writing; a solution to language problems; ability of evaluation; a solution to plagiarism; influences of search habits; concerns about graduate students; and the importance of professors. Four major findings of the study include: important uses of online resources for solving language problems; students’ search skills in online databases; students’ use of the UVic library; and the importance of professors’ instruction. These findings will be helpful for educators to consider as they work to integrate online resources for international students’ writing instruction; and for academic libraries to consider as they offer services to assist EFL/ESL learners. / Graduate / 2017-12-05 / 0727 / 0399 / 0515 / ketien0421@gmail.com

This work deals with the description and analysis of image data, which related to the initial stages of the thin film growth. The introductory retrieval section includes a description of thin films and methods of their deposition. The following part is an overview of the growth models of thin layers. The heart of my thesis is the analysis and modification of morphological methods and interpretation of their results. The emphasis is placed on the statistical aspect of methods and their optimal implementation due to the accuracy of the results. The work shows how to modify the radial distribution function and methods based on so-called Voronoi and Delaunay triangulation tessellation so that they can better affect the character of test data. New methods are tested both on the experimental and model data. Then we examine their robustness, sensitivity and their mutual independence. At the conclusion it is introduced and analyzed a new model of thin film growth.