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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.
191

Harmonic Losses in Windings of Inverter-Fed High-Speed PM Motors / Förluster i lindningar av högvarviga PM maskiner med växelriktare

Yang, Yang January 2015 (has links)
This master thesis focuses on the estimation of losses in windings of a high-speed PermanentMagnet (PM) motor. The PM motor studied in this thesis is applied to a nut-runner systemwith specic characteristics such as operating at a high speed (30000 rpm), relatively smallsize and being slot-less. Previously published analytical models for calculation the losses inwindings are discussed in the literature study along with related background theory. Finiteelement method (FEM) 2D is applied in the simulations using FLUX v12. Simulations beginwith several conductors and bundles. Meanwhile, the analytical estimation of those caseswas carried out. The comparisons between results from both sources are discussed. Beforefurther investigations, the way of connection of bundles and conductors and the applicationof symmetrical conditions for following simulations are discussed. Furthermore, the wholewindings with a iron ring and the rotor are simulated step by step in FLUX. Eect of ironmaterial, lamination thickness and base value are investigated. Finally, losses in windingswith various situations are calculated and compared at 10 kHz and 20 kHz. / Detta examensarbete behandlar uppskattning av forluster i lindningarna hos en permanentmagnet(PM) hoghastighets-motor. PM-motorn som studerats i denna avhandling tillhor ettmutterdragarsystem avsett for industriellt bruk. Utmarkande egenskaper for denna ar hoghastighet (30000 rpm), relativt liten storlek och avsaknad av statorspar. Tidigare publiceradeanalysmodeller for forlustberakningar i lindningar diskuteras i litteraturstudien tillsammansmed tillhorande bakgrundsteori. Finita Element Metoden (FEM) 2D anvands i simuleringarna.FEM-studierna har utforts i FLUX v12. Studierna utfors initialt pa era ledareoch buntar parallellt med analytiska uppskattningar for dessa. Resultaten fran bada kallornajamfors och diskuteras. Vidare diskuteras olika mojligheter till anslutning av era ledare ochledarvarv, samt tillampning av symmetriska villkor for vidare simuleringar. Lindningarnasimuleras darefter stegvis tillsammans med en jarnring och rotor. Paverkan av jarnmaterial,laminat-tjocklek och basvarde utreds. Slutligen utfors forlustjamforelser i lindningarna forolika kongurationer vid 10 kHz och 20 kHz. / Buntade, ledare, FEM 2D, forluster, PM motor, yteekt och narhetseekt, vridna, lindningarna
192

La proposition ou le syntagme ? : Une analyse structurelle de trois articles français et de leurs traductions suédoises / Phrase or clause? : A structural analysis of three French articles and their Swedish translations

Näsström, Anna January 2022 (has links)
The present study is based on a translation into Swedish of three French journalistic articles on energy sobriety. The study aims at comparing the source and the target texts, with regard to clause frequency and the use of various clause and phrase categories. This analysis is linked to the structural differences between the two languages, that have been stated by researchers in contrastive linguistics. The clause and phrase categories in focus have been defined by Olof Eriksson (1997), and used as translation units in his contrastive study on the French and Swedish languages.  The results of the analysis prove that the Swedish translation is characterised by a considerably higher clause frequency than the French source texts. The reason is that the translation has led to more phrases being replaced by clauses, than the opposite. This divergency is conform to the stated differences between French and Swedish – a conclusion that also can be drawn regarding the most frequent shifts from phrase to clause categories, especially the ones including a participle phrase. However, not all observed shifts are obligatory, which means that the results could be somewhat different if the analysis was based on a translation conducted by someone else. In a future study, it would therefore be interesting to extend the analysis to include several versions of the same translated text.
193

Transposition des gros vaisseaux avec septum intact ou communication interventriculaire : échocardiographie fœtale et analyse NIRS périopératoire

Charbonneau, Laurence 08 1900 (has links)
Ce mémoire par article est une étude des différences hémodynamiques entre la dextro-transposition des gros vaisseaux (TGV) avec communication interventriculaire (CIV) et la TGV avec septum intact (SI) pendant la période fœtale et périopératoire. Il est à noter que SI fait référence au septum inter ventriculaire et non au septum inter auriculaire. La présence d’une communication inter auriculaire étant, comme nous le verrons dans ce travail, un élément important de la physiologie des fœtus/nouveau-nés porteur de TGV. Le document est divisé en deux parties importantes. La première partie est composée du chapitre 1 qui présente une revue de littérature détaillant les notions importantes à la compréhension de la problématique et du chapitre 2 qui décrit la méthodologie utilisée pour répondre à la question de recherche. On détaille d’abord les méthodes d’acquisition des échocardiographies fœtales ainsi que les principales mesures effectuées à partir de celles-ci. Ensuite, on y décrit les technologies de la spectroscopie proche infrarouge avancée et de la spectroscopie à corrélation diffuse (NIRS-DCS) permettant de recueillir les données hémodynamiques sur la microvascularisation cérébrale des nouveau-nés. La seconde partie est constituée du chapitre 3 qui est le manuscrit accepté au journal Ultrasound in Obstetric & Gynecology pour publication. Celui-ci décrit les différences hémodynamiques entre les patients ayant une TGV&CIV et les TGV&SI et présente les différences retrouvées en échocardiographie fœtale et en hémodynamie cérébrale périopératoire étudiée à l’aide de la NIRS avancée. Ensuite, nous présentons dans le chapitre 4 une discussion sur les principaux impacts cliniques et sur d’éventuelles améliorations. / This master’sthesis is composed of an article and a study. They present hemodynamic differences between patients with transposition of the great arteries (TGA) and ventricular septum defect (VSD), and TGA with intact ventricular septum (IVS) during fetal and perioperative periods. This document is divided into two principal sections. The first section includes Chapter 1 that presents a review of literature detailing important notions to understand the problematic, and Chapter 2, that describes the methodology used to answer our research question. First, we detailed acquisition data and measured parameters of the fetal echocardiography exams. Then, we describe advanced near infrared spectroscopy (NIRS-DCS) technology that allowed hemodynamic data acquisition on the cerebral microvascularization of neonates. The second section is composed of Chapter 3, the manuscript accepted in Ultrasound in Obstetric & Gynecology journal for publication. The aim of this article is to describe hemodynamic differences between patients with TGA&VSD and TGA&IVS. It describes fetal echocardiography and cerebral perioperative hemodynamic differences studied with advanced NIRS. Next, we present in Chapter 4 a more detailed discussion with principal impacts on the clinical field and future improvements.
194

Spelling in the Digital Age: Spell- checkers’ Impact on Writing : A quantitative study on the effects of spell- checkers on English grammar

Hussein, Naba January 2024 (has links)
Due to the increased usage of technology and its indicated aid in writing acquisition, it is important to investigate the effects of spell-checkers on the English language. Thus, this essay has conducted a quantitative study to ascertain if there has been an improvement or regression in English spelling with the aim of gathering an indication of if and how spelling has evolved and changed with the development of spell-checkers. This study intended to answer two main questions: “Has spelling improved after spell-checkers were invented?” and “Can spell-checkers be seen as an aid in helping people learn how to spell better?”. Texts from before the development of spell-checkers and texts from after were utilized and searched for possible misspellings, to identify whether spelling has improved or not. The main finding was that there was a numerical difference between the two groups of texts, with the older texts containing an average of 43% misspellings as opposed to the newer texts which comprised an average of 7% misspellings. Thus, it was concluded that with the emergence of spell-checkers, spelling has improved. In relation to the second question, this research detected that although spelling mistakes have decreased, certain misspellings and errors are occurring, such as errors in transposition and omission, indicating that spell- checkers might not in fact be an aid in improving spelling competence. However, more data is required with regard to the second question, thus the answer remains inconclusive, with the need for further data to reach an assertive answer.
195

Asynchronisme, stimulation cardiaque et resynchronisation biventriculaire dans les cardiopathies congénitales : état des lieux, résultats, perspectives / Dyssynchrony, pacing and resynchronization therapy in patients with grown-up congenital heart disease : current evidence, results and future

Thambo, Jean-Benoît 27 June 2011 (has links)
Le nombre d'adultes porteurs de cardiopathies congénitales, de plus en plus sévères est constante progression. A moyen voire long terme certain d’entre eux posent des problèmes d’insuffisance cardiaque et de troubles du rythme parfois létaux. La physiologie de ces complications est multi factorielle et s’écarte souvent des schémas habituels. L’asynchronisme ventriculaire présentent chez un nombre important d’entre eux est connu pour favoriser un remodelage ventriculaire conduisant à l’insuffisance cardiaque sur cœur sain.Dans ce travail en couplant données expérimentales animales et études cliniques, nous avons étudié : 1) l’impact aigu puis chronique de la resynchronisation biventriculaire sur un modèle animal d’insuffisance cardiaque droite mimant la tétralogie de Fallot et sur une population de patients ; 2) le rôle et la conséquence d’une stimulation conventionnelle sur une physiologie de ventricule droit systémique ; 3) l’effet délétère de la stimulation VD prolongée sur un modèle de cœur animal en cours de développement.Nous avons appris que 1) la resynchronisation biventriculaire permet un bénéfice hémodynamique significatif chez l’animal mais aussi sur une population de Fallot implantées ; 2) que l’asynchronisme généré par la stimulation conventionnelle est délétère pour la fonction du ventricule systémique mais aussi pour le cœur de l’enfant en cours développement. La resynchronisation est un traitement prometteur pour traiter l’insuffisance cardiaque mais pourrait aussi l’être pour en prévenir sa survenue. De nouvelles techniques d’implantation nous permettent aujourd’hui d’implanter des patients qui présentent beaucoup d’obstacles anatomiques et d’éviter nombre de complications grave de la stimulation. / The number of adults with severe congenital heart disease is constantly growing. At medium to long-term follow up, these patients may present with heart failure or conduction disorders, which may lead to death. The pathophysiology and clinical course of these complications is multi-factorial and may be different from that in patients without congenital heart disease. In normal hearts, electromechanical dyssynchrony is known to induce ventricular remodeling and heart failure. Ventricular asynchrony is also present in a substantial number of adults with congenital heart disease. In this study, we combined animal experiments and clinical studies to investigate: 1) the acute and chronic effect of biventricular resynchronization therapy on cardiac function in an animal model mimicking right ventricular heart failure in Tetralogy of Fallot, as well as in patients with Tetralogy of Fallot; 2) the consequences of conventional ventricular pacing in patients with ‘systemic right ventricle physiology’; 3) the effects of chronic right ventricular pacing in an animal model of the developing heart.We found that: 1) biventricular resynchronization induces significant hemodynamic benefit in the animal model of Tetralogy of Fallot as well as in Fallot patients; 2) ventricular asynchrony induced by conventional ventricular pacing is deleterious to the function of the systemic right ventricle; 3) chronic right ventricular pacing is harmful to the developing (pediatric) heart with normal biventricular anatomy. Cardiac resynchronization therapy is promising as a treatment for heart failure, but may also prevent heart failure. Nowadays, new implantation techniques allow us to implant pacing devices in patients with limited anatomical access due to prior surgery and help to avoid numerous severe complications of conventional pacing therapy
196

Algorithmes Rapides pour les Tours de Corps Finis et les Isogénies

De Feo, Luca 13 December 2010 (has links) (PDF)
Dans cette thèse nous appliquons des techniques provenant du calcul formel et de la théorie des langages afin d'améliorer les opérations élémentaires dans certaines tours de corps finis. Nous appliquons notre construction au problème du calcul d'isogénies entre courbes elliptiques et obtenons une variante plus rapide (à la fois en théorie et en pratique) de l'algorithme de Couveignes. Le document est divisé en quatre parties. Dans la partie I nous faisons des rappels d'algèbre et de théorie de la complexité. La partie II traite du principe de transposition : nous généralisons des idées de Bostan, Schost et Lecerf et nous montrons qu'il est possible de transposer automatiquement des programmes sans pertes en complexité-temps et avec une petite perte en complexité-espace. La partie III combine les résultats sur le principe de transposition avec des techniques classiques en théorie de l'élimination ; nous appliquons ces idées pour obtenir des algorithmes asymptotiquement optimaux pour l'arithmétique des tours d'Artin-Schreier de corps finis. Nous décrivons aussi une implantation de ces algorithmes. Enfin, dans la partie IV nous utilisons les résultats précédents afin d'accélérer l'algorithme de Couveignes et de comparer le résultat avec les autres algorithmes pour le calcul d'isogénies qui font l'état de l'art. Nous présentons aussi une nouvelle généralisation de l'algorithme de Couveignes qui calcule des isogénies de degré inconnu.
197

L’enseignement de la distinction entre le passé composé et l’imparfait en français langue seconde

Thibault-Lanctôt, Éveline 09 1900 (has links)
La présente recherche vise à décrire et comprendre l’enseignement de la distinction entre le passé composé et l’imparfait à partir des connaissances et conceptions des enseignants ainsi qu’à partir de leur matériel didactique. La distinction aspectuelle, plus précisément celle qui concerne le perfectif et l’imperfectif, est une difficulté qui concerne plusieurs langues. La recherche antérieure s’est beaucoup intéressée à cette question, permettant de comprendre les raisons de cette difficulté qui se fonde sur l’hypothèse de l’aspect. À partir de cette hypothèse, les difficultés concernant la distinction entre le passé composé et l’imparfait s’éclaircissent, permettant d’ajuster les explications et la transposition didactique. Or, la recherche antérieure considère que les manuels didactiques fournissent aux apprenants et aux enseignants des explications qui ne permettent pas une réelle compréhension de la distinction entre le passé composé et l’imparfait. La présente recherche cherche à vérifier ces hypothèses. À partir d’entrevues réalisées auprès de neuf enseignants de français langue seconde, les résultats montrent qu’effectivement, les enseignants s’inspirent des manuels didactiques pour expliquer et transposer la distinction entre le passé composé et l’imparfait. De plus, à partir du matériel didactique fourni par les mêmes enseignants, les résultats montrent que malgré une connaissance de la difficulté d’emploi du passé composé et de l’imparfait, les exercices ne sont pas adaptés aux difficultés des étudiants. Enfin, la présente recherche démontre la prédominance de l’intrant typique par rapport à l’intrant atypique. / Second language (L2) acquisition researchers report that acquiring the perfective-imperfective distinction poses significant challenges to L2 learners. Previous research has focused on identifying the causes of this problem as well as investigating the differential effects of teaching methods. This study uncovers teachers’s knowledge and comprehension of the distinction between passé composé and imparfait and analyzes the teaching material they use in their classrooms. The Aspect Hypothesis has already been identified as the principal cause of L2 learners’ reported difficulties. By analysing data obtained from teacher interviews and from their teaching materials, the present study sets out to address these hypotheses. Nine teachers of French as a second language participated in a semi-structured interview and discussed the teaching material they used to teach the passé composé and imparfait distinction. The obtained results show that teachers rely on textbooks to explain and teach the distinction between passé composé and imparfait. Although teachers were aware of the difficulties associated with the acquisition of the target forms, they used exercises that did not facilitate the learners’ task. In fact, the provided exercises barely focused on the meaning and use of the forms in question and heavily focused on their formal properties. An analysis of the input to which the learners were exposed indicates the predominance of typical input.
198

Nenáležitá transpozice směrnice EU s příklady České republiky / Improper transposition of an EU directive with examples from the Czech Republic

Juha, Jan January 2014 (has links)
Improper transposition of an EU Directive is a phenomenon that occurs in quite an appreciable amount and in the performance of duty of individual Member States this represents a relatively common, although undesirable situation. The submitted diploma thesis deals with this issue within the Czech Republic in the light of individual proceedings for the failure to fulfill an obligation resulting from EU Treaties, which were concucted against the Czech Republic. This thesis is divided into six chapters, based on the theoretical foundations that are subsequently applied in practical examples. The first chapter presents the theoretical center of gravity for embedding the concept of primary and secondary law with emphasis on the EU Directive, while the this EU legislation is analyzed both in general terms and in terms of its structure. The following second chapter then gives an explanation to the issue of proper and improper transposition of an EU Directive and individual consequences that are associated with improper transposition of an EU Directive. The practical part starts from the third chapter, which contains analytical summarization of the all proceedings against the Czech Republic, which were conducted because of improper transposition of an EU Directive and ended with a judgement, while the fourth chapter...
199

Pohybová aktivita pacientů po Senningově korekci transpozice velkých tepen / Physical activity in patients after Senning procedure for transposition of the great arteries

Přádová, Kateřina January 2014 (has links)
Background: The transposition of the great arteries (TGA) is a common congenital heart disease. In the 1980s the Senning procedure was the major approach in correction of TGA in the Czech Republic. Although the most recent operation technique called arterial switch is the method of first choice nowadays, patients after Senning procedure are still visiting the cardiology centre. The aim of this thesis was to evaluate the relationship between the selected parameters from the exercise test and quantified level of physical activity (PA) in these individuals. Methods: 71 patients after the Senning procedure underwent a cardiopulmonary exercise test and they completed an international physical activity questionnaire (IPAQ). Selected data from the questionnaire and the exercise test were evaluated by Pearson correlation coefficient (p < 0,05). Results: 56 patients meet criteria of IPAQ (71 % male, n = 40) and were included in the study. Total PA averaged 6576 ± 5204 MET-minutes/week (median 5271 MET-minutes/week) and 70 % individuals meet criteria for high level of PA according to IPAQ data. Peak VO2 averaged 31,9 ± 6,6 ml/min/kg, maximum heart rate was 177 ± 18,6 beats per minute, the highest work load was 2,7 ± 0,8 W/kg and systolic blood pressure was 185 ± 24,0 mmHg. We found statistically significant...
200

Symbol, znak. Citace a používání uměleckého díla jako tvůrčí princip / Symbol, sign. Citations and use of work of art as a creative principle

Fricová, Soňa January 2013 (has links)
The thesis is dedicated to a postmodern use of symbol and sign. It is based on set definitions of major terms in the fine art and maps the space between a word and a picture as well as impersonal understanding of computer-generated codes. Didactic part enables to work with symbol and sign in art education. An analytical and syntactical thinking, the knowledge of the art history and the ability of intellectual fabrication are the basic ideas of the thesis. Art works, that use multilevel symbol expressions and are formally based on a postmodern thinking, are introduced in a practical part of the thesis.

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