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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.
281

Réseaux sans fil de nouvelle génération : architectures spontanées et optimisations inter-couches

Grunenberger, Yan 03 December 2008 (has links) (PDF)
Cette thèse propose une nouvelle approche pour la concrétisation des réseaux sans fil de nouvelle génération et de leurs nouveaux usages. Elle privilégie une séparation tem- porelle de la pile réseau, avec une première partie dédiée aux opérations temps réel, et une seconde partie organisée autour d'une architecture de traitement de paquets, construite dans un même espace permettant ainsi des optimisations inter-couches. La faisabilité de cette approche est vérifiée tout d'abord par l'étude des plates-formes flexibles permettant la réalisation de nouvelle méthode d'accès, puis au travers de PACMAP, un outil de manipulation de paquet en espace utilisateur, dont les fonc- tionnalités seront illustrées au travers du prototypage d'une solution originale au pro- blème de la mobilité, Virtual AP.
282

Swedish Dimensional Adjectives

Vogel, Anna 04 June 2004 (has links) (PDF)
The purpose of this study is to give a thorough and detailed account and analysis of the semantics of twelve Swedish dimensional adjectives: hög ‘high/tall', låg ‘low', bred ‘broad/wide', smal ‘narrow/thin', vid ‘broad', trång ‘narrow', tjock ‘thick', tunn ‘thin', djup ‘deep', grund ‘narrow', lång ‘long' and kort ‘short'. Focus has been placed on their spatial, non-metaphorical sense. The study was written within the framework of cognitive linguistics, where lexical definitions may be given in terms of prototypical and peripheral uses. Four sources of data have been considered: a corpus, consisting of contemporary fiction, an elicitation test, designed for the purpose, dictionary articles on the pertinent adjectives, and the author's own linguistic intuition as a native speaker. The methodology has involved categorisation of combinations of adjective and noun, based upon three major themes: orientation, function, and shape. In order to determine prototypical uses, precedence has been given to the outcome of the elicitation test over the corpus search. For both sources, frequency has played an important part. The ranking of senses as stated in the dictionary articles has also been considered. The results indicate that the dimensional adjectives differ quite markedly from each other, as opposed to a structural view where the adjectives traditionally have been regarded as forming a neat patchwork. Adjectives overlap each other for some uses (högt gräs ‘high grass', långt gräs ‘long grass' and even djupt gräs ‘deep grass'), while there are also situations in which no dimensional adjective can describe an object. Furthermore, adjectives forming pairs, such as djup – grund ‘deep – shallow', do not exhibit full antonymy, despite the fact that dimensional adjectives are traditionally cited as examples par excellence concerning antonymy.
283

FE safety analysis of a high speed wood planer cutter. An alternative method to achieve the requirements of EN847 standard / FE safety analysis of a high speed wood planer cutter. An alternative method to achieve the requirements of EN847 standard

Marques Novo, Francisco José, Saraiva Rézio, Henrique Manuel January 2004 (has links)
<p>In the last decades, high speed cutting has become an attractive technology in the wood industry. The possibility of reducing global costs in addiction with an increase in productivity, were the main reasons for the enlargement of the use of this technology. </p><p>As usual, these advantages are accompanied by disadvantages that should be carefully analyzed. If on the one hand cutting forces are reduced with increasing cutting speeds, on the other hand, the centrifugal forces affecting the tool are higher. Exposed to such high loads, there is a considerable risk of tool failure that embeds hazards for both machine and workers. </p><p>To prevent the risk of accidents and to guarantee safety in use, security standards have been implemented in industrial fields, imposing specific experimental tests, with defined procedure modes. Accordingly with these standards, the results obtained through the tests should fall inside limited ranges. The experimental tests suggested on the European Standards are intended to simulate the real working conditions of a rotating cutting tool, where extreme centrifugal forces are imposed by the high values of speed. Although their main importance, these destructive tests aren’t always practicable. It happens, for instance, with tools produced in small batch sizes, or as an ascertainment for the fail-critical speed during the development stage, or even due to physical incompatibilities between the tool and the laboratory testmachines. </p><p>The high value of weight associated with the cutting tool prototype developed and patented by Verktygs Larsson AB was an impediment to run the laboratorial tests specified by the standards, forcing the company to find a new way to assure the safety requirements of their product. </p><p>The main goal of this project was the development of an alternative method based on finite element theory to perform a safety analysis to the prototype of a wood cutter. This tool is used as a component in high speed planers. </p><p>In addiction to this primary objective, some considerations were made about other available models, with increased dimensions or even with different parameters. If there was the need, design changes could be assumed in order to guarantee that the tool reached the requisites of the safety standards. Considering an optimization effort, material changes would also be considered, to aim in the direction of reducing the tool weight and the consequent centrifugal forces.</p>
284

Emotion lexicon in the Sepedi, Xitsonga and Tshivenda language groups in South Africa : the impact of culture on emotion / T. Nicholls

Nicholls, Tanja January 2008 (has links)
Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2008.
285

LIMITATION DE COURANT À BASE D'OXYDES SUPRACONDUCTEURS ET RÉALISATION D'UN APP ARE IL 100 A - 1 KV

Belmont, Olivier 12 May 1999 (has links) (PDF)
Les courants de court-circuit n'ont cessé de croître sur les réseaux de distribution électrique pour répondre à l'augmentation de la consommation et pour pènnettre de fournir une meilleure qualité de service grâce à la plus grande interconnexion du réseau. Les limiteurs de courant supraconducteurs apportent une solution sans aucun équivalent classique pour réduire, avant l'ouverture des protections, ces courants de défauts. La découverte des supraconducteurs à haute température critique en 1986 a pennis de réduire leur coût d'utilisation dans des applications industrielles. Dans cette optique, nous avons étudié la transition des supraconducteurs à base de Bismuth ou d'yttrium pour l'appliquer à la réalisation du prototype de limiteur de courant résistif"Aster" : 100 A - 1 kV. Un limiteur de courant peut être dans trois états différents, en fonction du courant qui le traverse: état passant, état de limitation ou état de récupération. En régime nominal ou état passant, les pertes proviennent soit des pertes en courant alternatif tant que le courant est inférieur au courant critique, soit de la résistance due au début de la transition du supraconducteur. La résistance développée lors de la transition du supraconducteur pennet de limiter les courants de court-circuit. Cette transition se pass~ en deux étapes pour les matériaux frittés: elle est d'abord initiée au niveau des joints de grains, puis, lorsque le matériau a atteint sa température critique, il transite en masse. Une fois le courant limité, le limiteur est isolé du réseau pour pennettre au matériau de retrouver son état supraconducteur. Enfin nous avons réalisé et testé un appareil "limiteur de courant" autonome et répétitif. Les tests sous 500 V puis 1 kV nous ont pennis de valider le principe et le fonctionnement de l'ensemble.
286

FE safety analysis of a high speed wood planer cutter. An alternative method to achieve the requirements of EN847 standard / FE safety analysis of a high speed wood planer cutter. An alternative method to achieve the requirements of EN847 standard

Marques Novo, Francisco José, Saraiva Rézio, Henrique Manuel January 2004 (has links)
In the last decades, high speed cutting has become an attractive technology in the wood industry. The possibility of reducing global costs in addiction with an increase in productivity, were the main reasons for the enlargement of the use of this technology. As usual, these advantages are accompanied by disadvantages that should be carefully analyzed. If on the one hand cutting forces are reduced with increasing cutting speeds, on the other hand, the centrifugal forces affecting the tool are higher. Exposed to such high loads, there is a considerable risk of tool failure that embeds hazards for both machine and workers. To prevent the risk of accidents and to guarantee safety in use, security standards have been implemented in industrial fields, imposing specific experimental tests, with defined procedure modes. Accordingly with these standards, the results obtained through the tests should fall inside limited ranges. The experimental tests suggested on the European Standards are intended to simulate the real working conditions of a rotating cutting tool, where extreme centrifugal forces are imposed by the high values of speed. Although their main importance, these destructive tests aren’t always practicable. It happens, for instance, with tools produced in small batch sizes, or as an ascertainment for the fail-critical speed during the development stage, or even due to physical incompatibilities between the tool and the laboratory testmachines. The high value of weight associated with the cutting tool prototype developed and patented by Verktygs Larsson AB was an impediment to run the laboratorial tests specified by the standards, forcing the company to find a new way to assure the safety requirements of their product. The main goal of this project was the development of an alternative method based on finite element theory to perform a safety analysis to the prototype of a wood cutter. This tool is used as a component in high speed planers. In addiction to this primary objective, some considerations were made about other available models, with increased dimensions or even with different parameters. If there was the need, design changes could be assumed in order to guarantee that the tool reached the requisites of the safety standards. Considering an optimization effort, material changes would also be considered, to aim in the direction of reducing the tool weight and the consequent centrifugal forces.
287

Judging the Immigrant : Accents and Attitudes / Att döma invandraren : Attityder till bruten svenska

Torstensson, Niklas January 2010 (has links)
Spoken language as a means of communication contains huge amounts of information apart from the linguistic message that is conveyed. It is often the first channel of interaction between people and based on the speaker’s manner of talk, we create a mental image of the speaker as a person, of the speaker’s background, origin and personal qualities. Through five case studies, this dissertation investigates how immigrants to Sweden are judged based on their foreign accents (Cases 1—3) and how the use of an interpreter in court can affect the legal process and the judging of the immigrant (Cases 4—5). Case 1 investigated Swedish students’ attitudes towards immigration and immigrants through a survey-based study and revealed that Swedish students hold predominantly positive attitudes towards immigrations and immigrants. Case 2, using accent imitation, asked if Swedish speakers have a cognitive prototype for British English accented Swedish and found that this was the case. This demonstrated that Swedes have models of accented Swedish accents. Case 3 asked Swedish students to rate their impressions of speakers of nine foreign accented Swedish voices on 18 six-point semantic differential scales. They also rated their impressions of each voice for five social factors. The results suggest that the listeners evaluated the voices based on perceived social desirability, or perceived cultural distance between the listener and the voice’s country of origin. Juxtaposing these findings with those of Case 1 suggests that even among a group who are positive to immigrants and immigration some groups of immigrants are more welcome than others. Case 4 examined discourse disfluencies in a bilingual court hearing and a Swedish-Polish bilingual court hearing in detail. The case showed that most of the dialogue-related difficulties have other sources than the interpreter, even if the interpreter at first glance often appeared to be part of the problem rather than part of the solution. Case 5 examined the interpreter’s role in courtroom dialogue situations through interviews with a court interpreter and a lay judge. The study found that the picture of the interpreter’s role differs between the various actors in the court setting. This, in combination with a lack of knowledge about cultural differences in dialogue strategies, creates complications, can have an impact on the perception of the witness and, ultimately, affect the legal rights of the accused. Furthermore, as the interpreter most frequently speaks foreign accented Swedish, the perception and evaluation of their foreign accented Swedish can further place some immigrant groups at a double legal disadvantage when being judged.
288

CPlanner : Kursplaneringsprototyp med Design Science och Scrum

Tobias, Eklund, Spehar, Joakim January 2013 (has links)
Utveckling av planeringssystem är ett komplext designproblem som kräver både en hög grad av flexibilitet men även struktur. I samband med planering är det ett flertal aktörer, aktiviteter och resurser som måste beaktas. Kunnandet när det gäller planering finns ofta koncentrerad till ett fåtal nyckelpersoner. Det är därför ingen tillfällighet att många företag, organisationer och även universitet idag bedriver sin planering i beprövade enanvändarsystem som Excel fast att det finns starkt behov för standardiserat fleranvändarsystem. Uppsala universitet är inget undantag trots dess storlek med över 40 000 studenter, 6 200 anställda, 130 utbildningsprogram och 2000 fristående kurser. Kursplaneringen bedrivs med hjälp av enanvändarsystem där man är beroende av ett antal nyckelpersoner för att planeringen skall fungera. Uppsatsens syfte är att undersöka och belysa den problematik som finns i samband med utveckling av planeringssystem genom att utveckla en prototyp för ett kursplaneringssystem. Den forskningsstrategi som används är Design Science och den utvecklingsmetodik som används är Scrum. Prototypen har utvärderats regelbundet under utvecklingen genom formativ utvärdering. Uppsatsens kunskapsbidrag utgörs av metodkunskap som visar hur Scrum och Design Science kan kombineras samt modellkunskap som visar den grundläggande strukturen för ett kursplaneringssystem. / Development of planning system is a complex design problem that requires both a high degree of flexibility but also structure. In the context of planning, there are several actors, activities and resources that must be considered. Expertise in planning is often concentrated in a few key individuals. It is therefore no coincidence that many businesses, organizations and even universities currently conducts its planning in proven single-user system like Excel even though there is a strong need for standardized multi-user system. Uppsala University is no exception, despite its size, with over 40,000 students, 6,200 employees, 130 programs and 2000 courses. Course planning is conducted using single-user system and which is dependent on a number of key individuals to plan to work. The essay aims to investigate and illustrate the problems that are associated with the development of the planning system by developing a prototype of a course scheduling system. The research strategy used is Design Science and the development methodology that is used is Scrum. The prototype has been evaluated regularly during development through formative evaluation. The essays knowledge contribution is methodological knowledge that shows both how Scrum and Design Science can be combined and model knowledge, which shows the basic structure of a course scheduling system.
289

Desarrollo de un sistema de tratamiento del agua de escorrentía superficial procedente de aparcamientos impermeables usando flujo ascendente y geotextiles

Fernández Barrera, Andrés H. 18 February 2010 (has links)
Esta tesis doctoral presenta la investigación del desarrollo de un prototipo de laboratorio de un sistema de captación, pretratamiento y tratamiento (SCPT) de la escorrentía proveniente de aparcamientos con firmes impermeables. El prototipo de SCPT fue estudiado en condiciones de funcionamiento inicial y a largo plazo. Las respuestas analizadas son las concentraciones de aceites y sólidos en el efluente y las eficiencias de depuración de dichos contaminantes. Finalmente, se analizó la capacidad del sistema de filtrado del SCPT para albergar colonias de microorganismos depuradores de hidrocarburos. Los niveles de depuración alcanzados por el prototipo de SCPT son superiores al 80% para el caso de los sólidos y al 90 % para los aceites, tanto en condiciones de inicio de operación, como a largo plazo tras catorce eventos de lluvia consecutivos. Además, se demostró que el sistema de filtrado es capaz de albergar colonias de microorganismos degradadores de hidrocarburo
290

Conception et Commande d'un Robot d'Assistance à la Personne

Qian, Yang 04 July 2013 (has links) (PDF)
Ce travail s'inscrit dans le cadre de la conception et réalisation d'un robot d'assistance à la personne. Dans cette thèse, nous nous intéressons particulièrement à la conception, à la modélisation et à la commande d'un robot manipulateur mobile. La conception mécanique couplée à un outil de simulation dynamique multi-corps nous a permis d'obtenir un modèle virtuel très réaliste. Le modèle cinématique du système a été obtenu en utilisant la méthode D-H modifiée. L'approche Bond graph et la méthode de Lagrange ont permis de construire le modèle dynamique. Un algorithme hybride qui combine la pseudoinverse du jacobien et la méthode RRT a été proposé pour la planification de mouvement d'un manipulateur redondant et rechercher de configurations continues, stables et sans collision. Un contrôleur basé sur les réseaux de neurones a été introduit pour la commande coordonnée d'un manipulateur mobile. Cette méthode ne nécessite pas un modèle précis du robot. Les paramètres inconnus sont identifiés et compensés en utilisant des réseaux de neurones RBF. Un algorithme de contrôle similaire est présenté pour la commande force/position d'un manipulateur mobile qui est soumis à des contraintes holonomes et nonholonomes. L'étude de la main robotique a été effectuée séparément avant d'être couplée au reste du système. Les modèles cinématique et dynamique du système main-objet ont été obtenus en utilisant les approches mathématiques et bond graph. Un algorithme est proposé afin d'assurer une prise ferme, éviter les dérapages et suivre les mouvements désirés. Les validations des modèles et des différentes lois de commande ont été effectuées grâce à la co-simulation Matlab/modèle virtuel

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