There is an apparent problem with children being abused in different ways in their everyday life and the lack of education related to these issues among working adults in the vicinity of these children, for example as social workers or teachers. There are formal courses in child interview training that teach participants how to talk to children in a correct manner. Avatar-mediation enables new methods of practicing this communication without having to involve a real child or role play face-to-face with another adult. In this study it was explored how a system could be designed in order to enable educational practice sessions where a child interview expert can be mediated through avatars in the form of virtual children. Prototypes were developed in order to evaluate the feasibility of the scenario regarding methods for controlling the avatar and how the avatar was perceived by the participants. It was found that there is a clear value in the educational approach of using avatar-mediation. From the perspective of the interactor it was found that using a circular radial interface for graphical representation of different emotions was possible to control a video-based avatar while simultaneously having a conversation with the participant. The results of the study include a proposed design of an interface, description of underlying system functionality and suggestions on how avatar behavior can be characterized in order to achieve a high level of presence for the participant.

The goal of this thesis is to describe teaching styles of two secondary mathematics teachers with very different approaches. One of them represents traditional frontal instruction and one prefers students to be more actively involved in the learning process. Their styles are compared based on their teaching a concrete mathematical topic, namely plane analytic geometry of lines. Examined teaching styles (frontal instruction and so-called realistic education) and selected research with a similar focus are described in the theoretical part of the thesis. The research consisted of observations in lessons of both teachers and a final test for their students. The acquired data has been analyzed by qualitative and quantitative methods. The teacher representing traditional frontal instruction emphasizes practising and explaining the new topic. Problems are solved by herself or one chosen student on the blackboard. Questions, which she is asking, require mainly short answers and are focused on reproduction of the previously learnt knowledge. During the lessons of the teacher who is the creator and also an exponent of the so-called realistic education, students are solving problems independently. New topics are discussed collectively, the teacher often asks questions focused on the application of previous knowledge,...

Les images de synthèse sont présentes à travers un grand nombre d'applications tel que les jeux vidéo, le cinéma, l'architecture, la publicité, l'art, la réalité virtuelle, la visualisation scientifique, l'ingénierie en éclairage, etc. En conséquence, la demande en photoréalisme et techniques de rendu rapide ne cesse d'augmenter. Le rendu réaliste d'une scène virtuelle nécessite l'estimation de son illumination globale grâce à une simulation du transport de lumière, un processus coûteux en temps de calcul dont la vitesse de convergence diminue généralement lorsque la complexité de la scène augmente. En particulier, une forte illumination indirecte combinée à de nombreuses occlusions constitue une caractéristique globale de la scène que les techniques existantes ont du mal à gérer. Cette thèse s'intéresse à ce problème à travers l'application de techniques d'analyse de formes pour le rendu 3D.Notre principal outil est un squelette curviligne du vide de la scène, représenté par un graphe contenant des informations sur la topologie et la géométrie de la scène. Ce squelette nous permet de proposer de nouvelles méthodes pour améliorer des techniques de rendu temps réel et non temps réel. Concernant le rendu temps réel, nous utilisons les informations géométriques du squelette afin d'approximer le rendu des ombres projetés par un grand nombre de points virtuels de lumière représentant l'illumination indirecte de la scène 3D.Pour ce qui est du rendu non temps réel, nos travaux se concentrent sur des algorithmes basés sur l'échantillonnage de chemins, constituant actuellement le principal paradigme en rendu physiquement plausible. Notre squelette mène au développement de nouvelles stratégies d'échantillonnage de chemins, guidés par des caractéristiques topologiques et géométriques. Nous adressons également ce problème à l'aide d'un second outil d'analyse de formes: la fonction d'ouverture du vide de la scène, décrivant l'épaisseur locale du vide en chacun de ses points. Nos contributions offrent une amélioration des méthodes existantes and indiquent clairement que l'analyse de formes offre de nombreuses opportunités pour le développement de nouvelles techniques de rendu 3D / Nowadays, computer generated images can be found everywhere, through a wide range of applications such as video games, cinema, architecture, publicity, artistic design, virtual reality, scientific visualization, lighting engineering, etc. Consequently, the need for visual realism and fast rendering is increasingly growing. Realistic rendering involves the estimation of global illumination through light transport simulation, a time consuming process for which the convergence rate generally decreases as the complexity of the input virtual 3D scene increases. In particular, occlusions and strong indirect illumination are global features of the scene that are difficult to handle efficiently with existing techniques. This thesis addresses this problem through the application of discrete shape analysis to rendering. Our main tool is a curvilinear skeleton of the empty space of the scene, a sparse graph containing important geometric and topological information about the structure of the scene. By taking advantage of this skeleton, we propose new methods to improve both real-time and off-line rendering methods. Concerning real-time rendering, we exploit geometric information carried by the skeleton for the approximation of shadows casted by a large set of virtual point lights representing the indirect illumination of the 3D scene. Regarding off-line rendering, our works focus on algorithms based on path sampling, that constitute the main paradigm of state-of-the-art methods addressing physically based rendering. Our skeleton leads to new efficient path sampling strategies guided by topological and geometric features. Addressing the same problem, we also propose a sampling strategy based on a second tool from discrete shape analysis: the opening function of the empty space of the scene, describing the local thickness of that space at each point. Our contributions demonstrate improvements over existing approaches and clearly indicate that discrete shape analysis offers many opportunities for the development of new rendering techniques

Bien que fort différents, les romans des années 1950 d’Alain Robbe-Grillet et les romans des années 1960 de Robert Pinget ont prétendu contester les formes littéraires que le XXe siècle a héritées du siècle précédent, et notamment la description dite « balzacienne ». Nous interrogeons ici les modalités linguistiques de cette contestation et l’ambiguïté littéraire de ce déni d’héritage. La relation entre la description telle que l’ont pratiquée d’une part ces deux « Nouveaux Romanciers » et d’autre part les grands auteurs réalistes du XIXe siècle est ici envisagée selon une triple perspective : le maintien ou non d’une textualité prototypiquement méronymique ; la construction langagière d’une réalité dont l’existence est soudain moins sûre ; l’effacement énonciatif et ses conséquences esthétiques. Selon une approche résolument technique, les descriptions romanesques de Pinget et de Robbe-Grillet sont donc ici systématiquement mises en regard de descriptions canoniques de Balzac, mais aussi de Flaubert et de Zola. La contestation du protocole réaliste repose en effet sur une reprise et un refus : la complexité textuelle, la confusion dénotative et reférentielle, l’instabilité énonciative permettent aux deux romanciers de procurer des descriptions à la fois hyperréalistes et antiréalistes. Tout en prenant acte de la différence radicale des deux auteurs, il s’agit finalement de montrer comment l’un et l’autre sont parvenus à mettre au point un protocole descriptif résolument nouveau, qui rende compte du monde en tant qu’il est et en tant qu’il échappe. / Although very different, the novels of the 1950s by Alain Robbe-Grillet and of the 1960s by Robert Pinget claimed to challenge the literary forms that the twentieth century has inherited from the previous century, including the description of Honoré de Balzac. We question here the linguistic modalities of this confrontation, as well as the literary ambiguity of this denial of inheritance.The relationship between the description as have practiced these two "New Novelists" and on the other hand the great realistic writers of the nineteenth century is considered here in a triple perspective: maintenance / defence - or not – of a textuality, which is prototypically based on meronymy ; the linguistic construction of a reality whose existence is suddenly uncertain ; the enunciative erasure and its aesthetic consequences. In a decidedly technical approach, the descriptions of the novels of and Robbe-Grillet and Pinget are systematically opposed to the canonical descriptions of Balzac, but also to some extent to Flaubert and Zola. Challenging the realistic protocol is indeed based both on a recovery and a refusal: the textual complexity, the denotative and referential confusion and the enunciative instability allow these two novelists to provide descriptions which can be considered hyperrealistic as well as antirealistic. Eventually, while acknowledging the radical difference between the two authors, the aim is to show how both writers have managed to develop a considerably new descriptive protocol that reflects the world as it is and as it escapes.

The research documented in this report had a twofold purpose. Firstly, it was to design and implement an intervention based on the theory of Realistic Mathematics Education (RME) aimed at improving the mathematical understanding of learners in two Grade 8 remedial mathematics classes, by revisiting the key number concepts of place value, fractions and decimals. In doing so, a second purpose was to investigate the viability and emerging characteristics of an intervention based on the theory of RME in such a setting (i.e. with low attainers to revisit key number concepts). Pending the realisation of these immediate outcomes, more distant outcomes in subsequent research would be: that learners' understanding and academic performance in mathematics improves and to develop a local instruction theory in using the RME theory to revisit the concepts of place value, fractions and decimals with low attaining learners in order to improve their understanding in this regard. Grade 8 low attainers were selected as the target group for this research as a result of the pending implementation of Mathematical Literacy as a compulsory subject for all learners, possibly from 2006. Currently in South Africa, learners who are not meeting the required standard by the end of their Grade 9 year are able to elect not to take mathematics through Grades 10, 11 and 12. When the new Further Education and Training (FET) policy is implemented, this will no longer be the case. All learners, who do not elect to take mathematics as a subject, will have to take Mathematical Literacy as a compulsory subject throughout Grades 10, 11 and 12. Although less detailed and abstract than the subject mathematics, the Mathematical Literacy curriculum still requires learners to have an understanding of key number concepts and also contains a substantial amount of algebra. As Grade 8 is when learners start working with algebra more formally, and is also their first year at secondary school, it was decided that this would be an appropriate year to try and diagnose and remediate problems in learners' understanding of the key number concepts, if and where possible. The intention was that this would then equip learners with a more appropriate structure of conceptualised knowledge of the above-mentioned concepts on which they could further construct their understanding of algebra. The study was carried out at a local urban high school in South Africa and the research design of this study was informed by two development research approaches (van den Akker&Plomp, 1993; Gravemeijer, 1994). Also, the study was only implemented with a small number of participants, within a bounded setting and without the intention to generalise the results. It was therefore regarded as a development case study. The results appear to indicate that it is viable to apply the theory of RME with low attaining Grade 8 learners in order to revisit the key number concepts of place value, fractions and decimals. Copyright 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Barnes, HE 2004, A developmental case study : implementing the theory of realistic mathematics education with low attainers, MEd dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-12032004-103122 / > / Dissertation (MEd (Curriculum design))--University of Pretoria, 2005. / Curriculum Studies / unrestricted

The work developed in this thesis focusses on the electrical activity of the heart, from the modeling of the action potential originating from cardiac cells and propagating through the heart, as well as its electrical manifestation at the body surface. The study is divided in two main parts: modeling the action potential, and numerical simulations. For modeling the action potential a dimensional and asymptotic analysis is done. The key advance in this part of the work is that this analysis gives the steps to reliably control the action potential. It allows predicting the time/space scales and speed of any action potential that is to say the shape of the action potential and its propagation. This can be done as the explicit relations on all the physiological constants are defined precisely. This method facilitates the integrative modeling of a complete human heart with tissue-specific ionic models. It even proves that using a single model for the cardiac action potential is enough in many situations. For efficient numerical simulations, a numerical method for solving the heart-torso coupling problem is explored according to a level set description of the domains. This is done in the perspective of using directly medical images for building computational domains. A finite element method is then developed to manage meshes not adapted to internal interfaces. Finally, an anisotropic adaptive remeshing methods for unstructured finite element meshes is used to efficiently capture propagating action potentials within complex, realistic two dimensional geometries.

This thesis proposes a concept of sampling, especially for path tracing like algorithms, for faster convergence of the scene, using a local radiance approximation in the scene with hemispherical harmonics, which allows more effective way of ray casting on the given surface. In the first part, the basics of photorealistic rendering are introduced together with commonly used algorithms for image synthesis. The mathematical apparatus used in this thesis is defined in the second part of the thesis. Subsequently, existing solutions in this area are presented. The following chapter summarizes state-of-the-art methods in this branch. The rest of this thesis is focused on proposal and implementation of already mentioned extension.

No description available.

This work is about a realistic visualization technique called raytracing. It studies its original form, its extensions and optimizations. Raytracing casts rays through pixels and follows their propagation in the scene, according to the physical laws. It enables rendering of correct shadows, reflections and refractions. Distributed raytracing serves for better visualization and advanced effects. One ray is replaced with a beam of rays that allows soft shadows, fuzzy translucency, depth of field and antialiasing. With the increasing number of rays, the render time rises as well, so it is needed to use some optimization techniques and tools. A way of using this rendering method for visualization of alcoholic beverages is also described.

<p>Terrain generation is a convoluted and a popular topic in the VFX industry. Whether you are part of the film/TV or gaming industry, a terrain, is a highly nuanced feature that is usually present. Regardless of walking on a desert like terrain in the film, Blade Runner 2049 or fighting on different planets like in Avatar, 3D terrains is a major part of any digital media. The purpose of this thesis is about developing a workflow for large-scale terrains using complex data sets and utilizing this workflow to maintain a balance between the procedural content and the artistic input made especially for smaller companies which cannot afford an enhanced pipeline to deal with major technical complications. The workflow consists of two major elements, development of the tool used to optimize the workflow and the recording and maintaining of the efficiency in comparison to the older workflow. </p> <p> </p> <p> My research findings indicate that despite the increase in overall computational abilities, one of the many issues that are still present is generating a highly advanced terrain with the added benefits of the artists and users’ creative variations. Reducing the overall time to simulate and compute a highly realistic and detailed terrain is the main goal, thus this thesis will present a method to overcome the speed deficiency while keeping the details of the terrain present.</p>