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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Modélisation 3D automatique d'environnements : une approche éparse à partir d'images prises par une caméra catadioptrique / Automatic 3d modeling of environments : a sparse approach from images taken by a catadioptric camera

Yu, Shuda 03 June 2013 (has links)
La modélisation 3d automatique d'un environnement à partir d'images est un sujet toujours d'actualité en vision par ordinateur. Ce problème se résout en général en trois temps : déplacer une caméra dans la scène pour prendre la séquence d'images, reconstruire la géométrie, et utiliser une méthode de stéréo dense pour obtenir une surface de la scène. La seconde étape met en correspondances des points d'intérêts dans les images puis estime simultanément les poses de la caméra et un nuage épars de points 3d de la scène correspondant aux points d'intérêts. La troisième étape utilise l'information sur l'ensemble des pixels pour reconstruire une surface de la scène, par exemple en estimant un nuage de points dense.Ici nous proposons de traiter le problème en calculant directement une surface à partir du nuage épars de points et de son information de visibilité fournis par l'estimation de la géométrie. Les avantages sont des faibles complexités en temps et en espace, ce qui est utile par exemple pour obtenir des modèles compacts de grands environnements comme une ville. Pour cela, nous présentons une méthode de reconstruction de surface du type sculpture dans une triangulation de Delaunay 3d des points reconstruits. L'information de visibilité est utilisée pour classer les tétraèdres en espace vide ou matière. Puis une surface est extraite de sorte à séparer au mieux ces tétraèdres à l'aide d'une méthode gloutonne et d'une minorité de points de Steiner. On impose sur la surface la contrainte de 2-variété pour permettre des traitements ultérieurs classiques tels que lissage, raffinement par optimisation de photo-consistance ... Cette méthode a ensuite été étendue au cas incrémental : à chaque nouvelle image clef sélectionnée dans une vidéo, de nouveaux points 3d et une nouvelle pose sont estimés, puis la surface est mise à jour. La complexité en temps est étudiée dans les deux cas (incrémental ou non). Dans les expériences, nous utilisons une caméra catadioptrique bas coût et obtenons des modèles 3d texturés pour des environnements complets incluant bâtiments, sol, végétation ... Un inconvénient de nos méthodes est que la reconstruction des éléments fins de la scène n'est pas correcte, par exemple les branches des arbres et les pylônes électriques. / The automatic 3d modeling of an environment using images is still an active topic in Computer Vision. Standard methods have three steps : moving a camera in the environment to take an image sequence, reconstructing the geometry of the environment, and applying a dense stereo method to obtain a surface model of the environment. In the second step, interest points are detected and matched in images, then camera poses and a sparse cloud of 3d points corresponding to the interest points are simultaneously estimated. In the third step, all pixels of images are used to reconstruct a surface of the environment, e.g. by estimating a dense cloud of 3d points. Here we propose to generate a surface directly from the sparse point cloud and its visibility information provided by the geometry reconstruction step. The advantages are low time and space complexities ; this is useful e.g. for obtaining compact models of large and complete environments like a city. To do so, a surface reconstruction method by sculpting 3d Delaunay triangulation of the reconstructed points is proposed.The visibility information is used to classify the tetrahedra in free-space and matter. Then a surface is extracted thanks to a greedy method and a minority of Steiner points. The 2-manifold constraint is enforced on the surface to allow standard surface post-processing such as denoising, refinement by photo-consistency optimization ... This method is also extended to the incremental case : each time a new key-frame is selected in the input video, new 3d points and camera pose are estimated, then the reconstructed surface is updated.We study the time complexity in both cases (incremental or not). In experiments, a low-cost catadioptric camera is used to generate textured 3d models for complete environments including buildings, ground, vegetation ... A drawback of our methods is that thin scene components cannot be correctly reconstructed, e.g. tree branches and electric posts.
182

Vorsicht Stufe!

Buck, Marc Fabian 23 February 2016 (has links)
In dieser Arbeit werden verschiedene Entwicklungsmodelle des Menschen vorgestellt und in ihrem Gebrauch in und für die Pädagogik kritisch reflektiert. Zunächst werden Vorüberlegungen zur Etymologie und Systematik der Begriffe Entwicklung (zwischen Natur und Kultur) und Modell (gegenüber Theorie, Simulation und Schema) angestellt. Anhand des Gangs von Beispiel zu Beispiel (Günther Buck) werden jeweils die Entwicklungsmodelle des Menschen von Rudolf Steiner, Maria Montessori, Jean Piaget, Lawrence Kohlberg, Erik Erikson und Werner Loch kritisch dargestellt und problematisiert. Es schließen sich bildungs- und erziehungstheoretische Überlegungen an, wie das Phänomen der Entwicklung heute in angemessener Weise behandelt werden kann. Anhand der dargestellten Modelle zeigt sich, dass nur ein von absoluter Teleologie und Linearität befreiter Entwicklungsbegriff mit modernen Vorstellungen pädagogischer Anthropologie und Ethik kompatibel sein kann. Deswegen können Entwicklungsmodelle lediglich eine veranschaulichende oder regulierende Funktion ausüben. Sie stehen jedoch so zumeist im Widerspruch zu den grundlegenden Momenten der freien Bildsamkeit und Mitbestimmung des Einzelnen im Erziehungsprozess. Eine Rehabilitation des Entwicklungsdenkens erweist sich dennoch als sinnvoll, da dieser in der Lage ist, auf die komplexe Genealogie menschlichen Lebens und die Möglichkeiten und Grenzen pädagogischer Einsätze zu verweisen. / The issue of developmental models of human beings and their implementation in both pedagogical practice and theory are critically reflected within this thesis. In the beginning, preliminary considerations of the etymology and systematization of development (between nature and nurture) and model (as opposed to theory, simulation, scheme) are framed. Based on Günther Bucks''s approach (from „Beispiel“ to „Beispiel“) several developmental models by Rudolf Steiner, Maria Montessori, Jean Piaget, Lawrence Kohlberg, Erik Erikson and Werner Loch are critically examined. Subsequently, considerations on addressing the phenomenon of development from the perspective of education theory and „Bildung“ in an appropriate contemporary way are given expression. On the basis of the outlined models it is depicted that only a concept of development that is exempt from absolute teleology and linearity can be compatible with modern ideas of educational anthropology and ethics. Hence, developmental models may only serve visualizing and regulating purposes. They often contradict fundamental principles such as „Bildsamkeit“ (the ability and necessity of self-forming) and participation within the process of education. Nevertheless, the rehabilitation of development thinking proves beneficial due to its ability to indicate the complex genealogy of human life and the opportunities as well as limitations of pedagogical actions.
183

Solutions optimales des problèmes de recouvrement sous contraintes sur le degré des nœuds / Optimal solutions of problems of finding spanning tree with constraints on the degree of the nodes

Merabet, Massinissa 05 December 2014 (has links)
Le travail que nous développons dans le cadre de cette thèse s'articule autour des problèmes de recherche de structure de recouvrement de graphes sous contrainte sur le degré des sommets. Comme l'arbre de recouvrement couvre les sommets d'un graphe connexe avec un minimum de liens, il est généralement proposé comme solution à ce type de problèmes. Cependant, pour certaines applications telles que le routage dans les réseaux optiques, les solutions ne sont pas nécessairement des sous-graphes. Nous supposons dans cette thèse que la contrainte sur le degré est due à une capacité limitée instantanée des sommets et que la seule exigence sur le recouvrement est sa connexité. Dans ce cas, la solution peut être différente d'un arbre. Nous reformulons ces problèmes de recouvrement en nous appuyant sur une extension du concept d'arbre appelée hiérarchie de recouvrement. Notre objectif principal est de démontrer son intérêt vis-à-vis de l'arbre en termes de faisabilité et de coût du recouvrement. Nous considérons deux types de contraintes sur le degré : des bornes sur le degré des sommets ou une borne sur le nombre de sommets de branchement et cherchons dans les deux cas un recouvrement de coût minimum. Nous illustrons aussi l'applicabilité des hiérarchies en étudiant un problème prenant davantage en compte la réalité du routage optique. Pour ces différents problèmes NP-difficiles, nous montrons, tant sur le coût des solutions optimales que sur la garantie de performance des solutions approchées, l'intérêt des hiérarchies de recouvrement. Ce constat se voit conforté par des expérimentations sur des graphes aléatoires. / The work conducted in this thesis is focused on the minimum spanning problems in graphs under constraints on the vertex degrees. As the spanning tree covers the vertices of a connected graph with a minimum number of links, it is generally proposed as a solution for this kind of problems. However, for some applications such as the routing in optical networks, the solution is not necessarily a sub-graph. In this thesis, we assume that the degree constraints are due to a limited instantaneous capacity of the vertices and that the only pertinent requirement on the spanning structure is its connectivity. In that case, the solution may be different from a tree. We propose the reformulation of this kind of spanning problems. To find the optimal coverage of the vertices, an extension of the tree concept called hierarchy is proposed. Our main purpose is to show its interest regarding the tree in term of feasibility and costs of the coverage. Thus, we take into account two types of degree constraints: either an upper bound on the degree of vertices and an upper bound on the number of branching vertices. We search a minimum cost spanning hierarchy in both cases. Besides, we also illustrate the applicability of hierarchies by studying a problem that takes more into account the reality of the optical routing. For all those NP-hard problems, we show the interest of the spanning hierarchy for both costs of optimal solutions and performance guarantee of approximate solutions. These results are confirmed by several experimentations on random graphs.
184

Teorie poznání Rudolfa Steinera / Theory of Knowledge by Rudolf Steiner

Kasper, Vojtěch January 2021 (has links)
This thesis deals with the philosophical works of Austrian thinker, Rudolf Steiner (1861-1925). Focusing mainly on his epistemological thinking, its main objective is to interpret Steiner's Theory of Knowledge. This work is structured in four chapters. After giving the reader insight into Steiner's life, it goes on to deal with the development of his thinking and work, with particular attention paid to the substance of his first and truly philosophical (not yet theosofical- anthroposofical) phase of working life. Following from this is a passage on his relationship with J. W. Goethe, whose intellectual (and especially scientific) legacy served as Steiner's main source of inspiration, while also laying out the basic form of Goethe's scientific methodology and its epistemological background, namely its empirical and simultaneously objective idealism, which deeply spoke to Steiner and motivated him to write his first philosophical work: Grundlinien einer Erkenntnistheorie der Goetheschen Weltanschauung (1886). The third chapter approaches this particular work, in which Steiner presents and describes the theory of knowledge, as aligned with that of Goethe. Analysed and interpreted are the three main successive sections of his work, in which he expresses his notion of experience, thinking and knowledge....
185

5-sparse steiner triple systems

Wolfe, Adam J. 04 August 2005 (has links)
No description available.
186

Pedagogika Rudolfa Steinera v českém školství / The Rudolf Steiner's pedagogy in the Czech educational system

Klímová, Šárka January 2014 (has links)
The topic of this thesis is the pedagogy of Rudolf Steiner in the Czech educational system. The theoretical part is divided into three sections. The first chapter is dedicated to the founder of waldorf education Rudolf Steiner, it deals with his life, work and his legacy to the Czech pedagogical environment. The second chapter describes the free school of Rudolf Steiner, its origin, specifications and evolution of Steiner's education. The last chapter of the theoretical part is focused on Steiner's pedagogy in the Czech education system and studies application of the Steiner's pedagogy at each of the levels of the Czech school system. The empirical part deals with describtions of several Czech primary Steiner's schools and compares them from the point of view of chosen areas of origin, evolution and implementation of Rudolf Steiner's ideas. In the last chapter of the thesis the before mentioned areas of Czech Steiner's schools are compared in short with Steiner's schools in the Eindhoven in Netherlands. Keywords Rudolf Steiner, waldorf education, anthroposophy, Czech waldorf schools, Steiner's special education, eurythm
187

Rozšířený binární Golayův kód / Extended binary Golay code

Uchytilová, Vendula January 2011 (has links)
This work deals with three different constructions of the extended binary Golay code G24. The first construction is based on a projective plane of order four. In terms of it Steiner system (5, 8, 24) is built. Linear span of its blocks forms a linear binary [24, 12, 8] code C. Every binary [24, 12, 8] code is isomorphic to C which is known as extended binary Golay code G24. The second construction uses so-called Miracle Octad Generator (MOG). All MOG-words of weight eight form Steiner system (5, 8, 24). The third construction uses impartial combinatorial game Mogul. In terms of its P-positions one can create a linear binary [24, 12, 8] code. The fact that is is also a lexikographic code is useful for parametres estimate. 1
188

Untere Schranken für Steinerbaumalgorithmen und die Konstruktion von Bicliquen in dichten Graphen

Kirchner, Stefan 02 September 2008 (has links)
Die vorliegende Arbeit besteht aus zwei Teilen. Der erste Teil der Arbeit befasst sich mit unteren Schranken für approximative Steinerbaumalgorithmen. Ein Steinerbaum ist ein kürzester Teilgraph, der eine gegebene Teilmenge der Knoten eines Graphen spannt. Das Berechnen eines Steinerbaumes ist ein klassisches NP-schweres Problem, und es existieren mehrere Approximationsalgorithmen, wobei bei den meisten Algorithmen die Approximationsgüte nur durch untere und obere Schranken eingegrenzt werden kann. Für einige dieser Algorithmen werden in dieser Arbeit Instanzen vorgestellt, welche die unteren Schranken verbessern. Für den Relativen Greedy Algorithmus wird außerdem ein Verfahren vorgestellt, mit dem die Güte des Algorithmus eingeschränkt auf die Graphenklasse mit k Terminalen auf einen beliebigen Faktor genau bestimmt werden kann. Der zweite Teil der Arbeit widmet sich vollständig bipartiten Subgraphen mit gleicher Partitionsgrößse, sogenannten balancierten Bicliquen. Seit langem ist bekannt, dass in dichten bipartiten Graphen balancierte Bicliquen mit Omega(log(n)) Knoten existieren, aber es ist unbekannt, ob und wie diese in polynomieller Zeit konstruiert werden können. Der zweite Teil liefert dazu einen Beitrag, indem ein polynomieller Algorithmus vorgestellt wird, der in hinreichend großen dichten bipartiten Graphen eine balancierte Biclique mit Omega(sqrt(log(n))) Knoten konstruiert. / This thesis consists of two parts. The first part is concerned with lower bounds for approximating Steiner trees. The Steiner tree problem is to find a shortest subgraph that spans a given set of vertices in a graph and is a classical NP-hard problem. Several approximation algorithms exist, but for most algorithms only lower and upper bounds for the approximation ratio are known. For some of these algorithms we present instances which improve the lower bounds. When the problem is restricted to the class of graphs with k terminals, we also present a method which can be used to determine the approximation ratio of the Relative Greedy Algorithm with arbitrary precision. The second part is about balanced bicliques, i.e. complete bipartite subgraphs with equal partition sizes. It has been known for a long time that every dense bipartite graph contains a balanced biclique of size Omega(log(n)), but whether and how such a biclique can be constructed in polynomial time is still unknown. Our contribution to this problem is a polynomial time algorithm which constructs a balanced biclique of size Omega(sqrt(log(n))) in sufficiently large and dense bipartite graphs.
189

Building a strong brand with marketing communications at the cognitive, affective, and behavioral level. - Case Södertörn University

Ekberg, Charlotte January 2010 (has links)
<p><strong>Aim:</strong> The purpose of this paper is to investigate how Södertörn University may build a stronger brand through marketing communications. The paper discussed each stage of the buying process. With models like these it is possible to measure the number of consumers who occupy the different stages.</p><p><strong>Method:</strong> The data was collected in a non-random convenience selection at the Stockholm fair for higher education with 21 000 visitors. I used a survey questionnaire. The number of respondents was 409 respondents. My method of investigation is quantitative. It is measurable so that communication goals can be set. In order to build a stronger brand I analyzed prospective students and their awareness of Södertörn University. The study has a positivistic view and a deductive approach.</p><p><strong>Result & Conclusions: </strong>My study shows that Södertörn University should use marketing communication strategically by using the models. At the cognitive level the most important is to raise brand awareness. Total knowledge is 52% in Stockholm County which is too low. An increase is fatal to raise the number of applicants. At the affective level they have to increase brand attitude. At the Behavioural level they need to increase brand purchase intention and facilitate purchase.</p><p><strong>Suggestions for future research:</strong> It would be interesting to use other models of consumer responses too. Next step could be to make interviews with students to be to study how they first got to know the name, and what has affected them in order to choose or not to choose the university.</p><p><strong>Contribution of the thesis: </strong>The thesis has actually contributed a lot to Södertörn University. I have used the collected data to make a marketing plan. We now have worked a lot with awareness and seen a great increase in applications.</p>
190

Mondrian och Teosofin : <sub>influenser på resan mot det abstrakta måleriet</sub> / Mondrian and theosophy : influences on the journey to abstract painting

Bjelm, Ellinor January 2009 (has links)
<p>Målet är att få en bättre förståelse för hur det abstrakta måleriet uppkommit och för att göra detta möjligt har jag valt att utgå ifrån en av de abstrakta pionjärerna, Piet Mondrian. I undersökningen finns ett fokus på att ta reda på vilka hans inspirationskällor var och hur de återspeglar sig i hans konst. En diskussion och bildanalys förs kring ett antal av Mondrians målningar samt ett par jämförelser görs med konstnären Toorop. Det finns en kortare förklaring av neoplasticismen, teosofin och en sammanfattning av teosofins roll för de abstrakta pionjärerna.</p><p>Det jag kommit fram till är att teosofin hade en stor betydelse för Mondrian, men inte lika stor betydelse som personerna som förmedlade den och som kom att bli inspirationskällor för honom. Enligt mig är den mest betydande målningen Evolution från tidigt 1900-tal. Under denna tid sker mycket i Mondrians privata och professionella liv. I målningen kan vi utläsa både inspirationskällor och teknik. Det som betydde mest för Mondrian var färgen (före formen) samt de delar ur teosofin som han plockade efter att ha låtit sig inspireras av Toorop, Steiner och Schoenmaeker.</p>

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