The blendshape is an effective tool in computer facial animation, enabling represention of muscle actions. Limitations exist, however, in the level of realism attainable under conventional use of blendshapes as non-intersecting deformations. Using the principle of superposition, it is possible to create a facial model with overlapping blendshapes and achieve more realistic performance. When blendshapes overlap, the region of intersection is in superposition and usually exhibits undesired surface interference. In such cases we use a corrective blendshape to remove the interference automatically. The result is an animatable facial model implemented in Maya which represents the effects of muscle action superposition. Performance created with our model of a known human subject is compared to 3D scan reference data and video reference data of that person. Test animation is compared to video reference footage. The test animation seems to mimic the effects of actual muscle action superposition accurately.

Twenty full-scale unreinforced masonry walls were constructed and tested to failure in the Structures Laboratory at the University of Saskatchewan. The focus of the testing related to two primary objectives. The first objective was to study the effects that the support conditions of the walls had on their behaviour. The masonry wall specimens tested spanned vertically under the application of out-of-plane loads. Ten of the full scale walls were tested with support conditions that modeled ideal pinned connections at the top and bottom of the wall, while the remaining half of the walls were tested with nominally “pinned” supports that were similar to the supports typically encountered in practice. The second objective was to determine the effects that dynamic loads had on the behaviour of the walls. Half of the masonry specimens for each group of support conditions were loaded laterally with monotonically increasing quasi-static loads representative of the effects of uniform wind pressure, while the remaining specimens were loaded laterally with dynamic time histories that varied randomly in a manner that was representative of real “gusty” winds. The research was therefore done to determine the influence of load and connection type on the behavior of the masonry walls. When comparing the effects of the support conditions, it was found that the walls constructed with realistic support conditions were able to resist larger out-of-plane loads, with greater ductility than the walls that had ideally-pinned supports. Specifically, the realistically-pinned walls required an average moment (of both the statically and dynamically loaded walls) that was 63% larger to cause mid-height cracking than the average mid-height moment required to cause mid-height cracking in the ideally-pinned walls. After mid-height cracking occurred, the realistically-pinned walls exhibited reserve capacity, resulting in additional strength, such that the ultimate moment capacity of the realistically-pinned walls was 140% greater than the ultimate strength of the ideally-pinned walls, where the ultimate strength was the capacity of the wall at mid-height cracking. As a result, the ductility of the realistically-pinned walls was also significantly larger than that of the ideally-pinned walls. Specifically, the ductility ratio of the realistically-pinned walls was 70 (where the ductility ratio is defined as the displacement at the ultimate load divided by the displacement at mid-height cracking), while the ductility ratio of the ideally-pinned walls was unity (the ultimate load coincided with formation of the mid-height crack). The results of the dynamically and quasi-statically loaded walls were harder to evaluate. In comparing the ideally-pinned walls it was found that the specimens that were loaded dynamically had an average moment capacity that was approximately 10% larger than the walls that were loaded quasi-statically, which was found to be statistically significant at the 90% level. However, the results from the realistically-pinned walls were not as conclusive. At mid-height cracking the dynamically loaded walls had an average moment capacity that was 24% lower than the quasi-statically loaded walls, which seems to contradict with the data from the ideally-pinned walls and from the literature suggesting that dynamic strengths should be higher. At the ultimate condition, the dynamically loaded walls had an average strength that was 12% larger than the quasi-statically loaded walls; however, these comparative results were not statistically significant at the 90% confidence level. It was also found that the dynamic loading failed the wall specimens as a result of sustained, large amplitude “gusts” rather than at the largest instantaneous peak load. The displacement behaviour of the walls was generally independent of the method of loading, but, rather, largely dependent on the support conditions. The collapse of the wall specimens were all initiated when they reached a geometrically unstable displaced shape that was fairly consistent for a given support configuration, regardless of the type of load that was applied. Lastly, results from a numerical model suggested that the dynamically loaded walls exhibited higher apparent stiffness properties as compared to the quasi-statically loaded walls. The difference in the apparent stiffness between the dynamic and quasi-static specimens decreased with increasing damage levels until the dynamic stiffness converged to the static stiffness near the collapse of the walls.

In this thesis, I develop a program to automatically assemble collage sculptures, sets of arbitrary, non-overlapping elements arranged to fill out a recognizable target shape according to a set of procedural rules. A user provides the target and element shapes and the program procedurally places the elements in spherical holes in the target space. A signed distance function defined over the target space keeps track of the remaining holes to fill. Elements are preprocessed to determine the size of their smallest enclosing bounding sphere. They are placed in holes based on the radius of their bounding sphere. After each placement, the signed distance function is efficiently updated to account for the newly added element. Elements are placed from largest to smallest, filling the space to a predefined threshold. To demonstrate this program, I generated a number of collage sculptures. In accordance with our procedural rules, the elements in the resulting collage sculptures recognizably represent the target shape, do not overlap, are not deformed from their original shape, and display variety in size, position, and orientation.

Calculations of band-to-band impact ionisation rates performed in the semi-classical Fermi’s Golden Rule approximation are presented here for the semiconductors GaAs, In(_0.53)Ga(_0.47)As and Si(_0.5)Ge(_0.5) at 300K. The crystal band structure is calculated using the empirical pseudopotential method. To increase the speed with which band structure data at arbitrary k-vectors can be obtained, an interpolation scheme has been developed. Energies are quadratically interpolated on adapted meshes designed to ensure accuracy is uniform throughout the Brillouin zone, and pseudowavefunctions are quadratically interpolated on a regular mesh. Matrix elements are calculated from the pseudowavefunctions, and include the terms commonly neglected in calculations for narrow band gap materials and an isotropic approximation to the full wavevector and frequency dependent dielectric function. The numerical integration of the rate over all distinct energy and wavevector conserving transitions is performed using two different algorithms. Results from each are compared and found to be in good agreement, indicating that the algorithms are reliable. The rates for electrons and holes in each material are calculated as functions of the k-vector of the impacting carriers, and found to be highly anisotropic. Average rates for impacting carriers at a given energy are calculated and fitted to Keldysh-type expressions with higher than quadratic dependence of the rate on energy above threshold being obtained in all cases. The average rates calculated here are compared to results obtained by other workers, with reasonable agreement being obtained for GaAs, and poorer agreement obtained for InGaAs and SiGe. Possible reasons for the disagreement are investigated. The impact ionisation thresholds are examined and k-space and energy distributions of generated carriers are determined. The role of threshold anisotropy, variation in the matrix elements and the shape of the bands in determining characteristics of the rate, particularly the softness of the rate's threshold behaviour are investigated.

There are continuing concerns regarding literacy standards within education with these concerns having resulted in many literacy initiatives being introduced over the past 5 years. Much research has focussed on improving our understanding of literacy, our ability to identify literacy needs and our ability to subsequently address these needs. As a result of an independent review into the early teaching of reading the Government have promoted the use of the ‘Simple View of Reading’ (SVOR) in the Primary Framework for Literacy (DCSF, 2007c). The study reported in this thesis considers whether the Simple View of Reading is perceived by teachers as providing a useful framework for the identification of literacy learning needs. In addition, it also aims to contribute to our understanding of teacher development, identifying for whom, and in what circumstances, the introduction of the SVOR results in a change in practice. Teachers working within five primary schools participated in this study. Data was collected through questionnaires and a small number of follow up interviews. It is important to note that these findings are likely to have been influenced by certain changes in context during the study, for example the delegation of funding to schools, a reduction in central support services and the introduction of the Primary Framework for Literacy. Questionnaire data indicates that, on the whole, teachers perceived the SVOR as easy to use, as providing useful information and as providing an easy visual reference. Results also indicate reported increases in teacher understanding of, and use of, the SVOR, coupled with increased confidence relating to the identification of literacy learning needs. These differences were all statistically significant. Key findings from the interviews suggest that teachers who perceived the SVOR to be useful and helpful to them on a personal level, made links between the SVOR and their existing practice and were more concerned with improving outcomes for children rather than meeting their own personal needs were more likely to incorporate the SVOR into their practice. This study has implications for promoting the SVOR as a framework for identifying literacy needs, future teacher development and the use of realist research approaches within Educational Psychology.

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This thesis focuses on the problem of underwater target tracking with consideration for realistic conditions using active sonar. This thesis addresses the following specific problems: 1) underwater detection in three dimensional (3D) space using multipath detections and an uncertain sound speed profile in heavy clutter, 2) tracking a group of divers whose motion is dependent on each other using sonar detections corrupted by unknown structured background clutter, 3) extended target tracking (ETT) with a high-resolution sonar in the presence of multipath detection and measurement origin uncertainty. Unrealistic assumptions about the environmental conditions may degrade the performance of underwater tracking algorithms. Hence, underwater target tracking with realistic conditions is addressed by integrating the environment-induced uncertainties or constraints into the trackers. First, an iterated Bayesian framework is formulated using the ray-tracing model and an extension of the Maximum Likelihood Probabilistic Data Association (ML-PDA) algorithm to make use of multipath information. With the ray-tracing model, the algorithm can handle more realistic sound speed profile (SSP) instead of using the commonly-assumed constant velocity model or isogradient SSP. Also, by using the iterated framework, we can simultaneously estimate the SSP and target state in uncertain multipath environments. Second, a new diver dynamic motion (DDM) model is integrated into the Probability Hypothesis Density (PHD) to track the dependent motion diver targets. The algorithm is implemented with Gaussian Mixtures (GM) to ensure low computational complexity. The DDM model not only includes inter-target interactions but also the environmental influences (e.g., water flow). Furthermore, a log-Gaussian Cox process (LGCP) model is seamlessly integrated into the proposed filter to distinguish the target-originated measurement and false alarms. The final topic of interest is to address the ETT problem with multipath detections and clutter, which is practically relevant but barely addressed in the literature. An improved filter, namely MP-ET-PDA, with the classical probabilistic data association (PDA) filter and random matrices (RM) is proposed. The optimal estimates can be provided by MP-ET-PDA filter by considering all possible association events. To deal with the high computational load resulting from the data association, a Variational Bayesian (VB) clustering-aided MP-ET-PDA is proposed to provide near real-time processing capability. The traditional Cramer-Rao Lower Bound (CRLB), which is the inverse of the Fisher information matrix (FIM), quantifies the best achievable accuracy of the estimates. For the estimation problems, the corresponding theoretical bounds are derived for performance evaluation under realistic underwater conditions. / Thesis / Doctor of Philosophy (PhD)

Syftet med denna studie har varit att undersöka hur lärare på mellanstadiet ser på användandet av en matematik kopplad till elevers vardag och erfarenheter. Vad betyder det för dem, använder de det i sin undervisning, anser de att det hjälper eller hindrar eleven i sin inlärningsprocess? Undersökningen har varit empirisk och utförts genom intervjuer med fem lärare som alla har behörighet att undervisa i matematik på mellanstadiet. De resultat som framkommit visar att lärare använder sig av en konkretiserad matematik genom att ta hjälp av olika material och koppla uppgifter till de intressen och erfarenheter eleverna bär med sig. En del lärare menar att vissa elever påverkas negativt av det här då det finns vissa delar i en konkretiserad, vardagsanknuten, matematik som gör att de kan uppleva problem och förvirring. Andra lärare menar istället att de märker hur elevernas förståelse ökar och att de tycker att matematik är roligt när de ser hur skolmatematiken kan kopplas samman och relateras till deras vardag och närliggande miljö. / <p>Matematik</p>

Reproduire efficacement l'apparence réaliste des matériaux est un problème crucial pour la synthèse d'images réalistes dans les productions cinématographiques et les jeux vidéo. Outre le transport global de la lumière, le réalisme d'une image de synthèse passe avant tout par une modélisation correcte du transport local, c'est-à-dire les interactions entre lumière et matière. La modélisation de ces interactions donne lieu à une grande variété de modèles de réflectance. Nous proposons une classification de ces modèles en s'appuyant sur l'échelle des détails géométriques abstraits. À partir de cette classification, nous étudions des modèles de réflectance particuliers : * un modèle de transmission pour les surfaces transparentes et rugueuses, tels que le verre dépoli. Son efficacité permet une utilisation au sein applications temps-réel * une analyse et une modélisation du transport de la lumière dans les matériaux composés d'agrégats de particules * une base alternative aux harmoniques sphériques pour représenter et illuminer efficacement les matériaux mesurés ayant une réflectance à basses fréquences. Ces modèles permettent une abstraction efficace des interactions locales tout en conservant la reproduction de leurs effets réalistes. / Reproducing efficiently the appearance of complex materials is a crucial problem in the synthesis of realistic images widely involved in the production of video games and movies. Apart from global light transport, the realism of a synthetic image is in large part due to the adequate modeling of local light transport, i.e. the interactions between light and matter. Modeling these interactions gives rise to a large variety of reflectance models. We therefore propose a classification of these models based on the scales of their abstract geometric details. From this classification, we can study particular reflectance models: a transmitting reflectance model for transparent rough surfaces such a frosted glass. The efficiency of our model allows real-time performances, a study and a model of energy propagation in material composed of dense packed discrete particles, an alternative basis for representing and lighting efficiently measured materials having a low frequency reflectance. These models permit the abstraction of local interactions while keeping the realism of fully simulated local light transport models.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Katie (Mary Catherine) Kingery-Page / Landscape architecture lacks evidence-based theory for the communicative effectiveness of graphics used in representing design ideas to stakeholders. For the purpose of this study, communicative effectiveness is operationalized as visual communication that expresses accurately the design in a way that the receiver understands the intentions — programmatic, experiential or otherwise — of the design. People need graphic representation to grasp abstract concepts, and drawings can help one imagine what a place can look like years down the road (Hester 2007). Graphics inform the viewer about essential elements of the design and the broader impact that design has on future experiences (Coe 1981). Knowing how people perceive and understand design graphics is key to communicating effectively to clients and other stakeholders. Graphic communication is complex, and no formula exists for communication in landscape architecture (Kingery-Page and Hahn 2012; Ware 2014). The questions guiding this study are: What graphic representation styles increase the non-designers’ understanding of design proposals? Do degrees of abstraction or realism affect understanding of the design drawing? I identified three research phases to adequately answer the questions: Phase One: Site Design Development — I designed a site plan for the Manhattan Arts Center (MAC), a community arts center in Manhattan, Kansas. Design intentions were carefully outlined based on stakeholder input. Phase Two: Graphics Production — Visual representations of the site design were developed in styles ranging from formal abstract to more realistic, based on review of precedent images in academic and professional architectural publications. Phase Three: Evaluation of Graphics Through Focus Groups— The communicative effectiveness of the representations were tested through three focus groups of stakeholders. Content analysis of the recorded focus group sessions revealed patterns of understanding the graphics. Overall, participants revealed that the more real the abstraction, the less understanding takes place. Formal Abstraction communicates the physical dimensions of the design most effectively, and Formal Abstraction has relatively the same communicative effectiveness regarding experience of place. Quantitative and qualitative data informed the creation of theories and a framework practitioners may use for selecting the most effective graphic communication options appropriate to project and audience. Key Words: Effective visual representation, visual communication, graphic style, Formal Abstraction, Semi-Realistic Abstraction, Realistic Abstraction, drawings, design intent, design ideas, accurate, perception, understanding, stakeholders, non-designer, landscape architecture.