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The Global ETD Search service is a free service for researchers
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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.
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Showing 41 to 42 of 42 (0.034 seconds)Spelling suggestions: "subject:"mirroring"" "subject:"mirrorings""
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Contribution à la théorie des ondelettes : application à la turbulence des plasmas de bord de Tokamak et à la mesure dimensionnelle de cibles / Contribution to the wavelet theory : Application to edge plasma turbulence in tokamaks and to dimensional measurement of targetsScipioni, Angel 19 November 2010 (has links)
La nécessaire représentation en échelle du monde nous amène à expliquer pourquoi la théorie des ondelettes en constitue le formalisme le mieux adapté. Ses performances sont comparées à d'autres outils : la méthode des étendues normalisées (R/S) et la méthode par décomposition empirique modale (EMD).La grande diversité des bases analysantes de la théorie des ondelettes nous conduit à proposer une approche à caractère morphologique de l'analyse. L'exposé est organisé en trois parties.Le premier chapitre est dédié aux éléments constitutifs de la théorie des ondelettes. Un lien surprenant est établi entre la notion de récurrence et l'analyse en échelle (polynômes de Daubechies) via le triangle de Pascal. Une expression analytique générale des coefficients des filtres de Daubechies à partir des racines des polynômes est ensuite proposée.Le deuxième chapitre constitue le premier domaine d'application. Il concerne les plasmas de bord des réacteurs de fusion de type tokamak. Nous exposons comment, pour la première fois sur des signaux expérimentaux, le coefficient de Hurst a pu être mesuré à partir d'un estimateur des moindres carrés à ondelettes. Nous détaillons ensuite, à partir de processus de type mouvement brownien fractionnaire (fBm), la manière dont nous avons établi un modèle (de synthèse) original reproduisant parfaitement la statistique mixte fBm et fGn qui caractérise un plasma de bord. Enfin, nous explicitons les raisons nous ayant amené à constater l'absence de lien existant entre des valeurs élevées du coefficient d'Hurst et de supposées longues corrélations.Le troisième chapitre est relatif au second domaine d'application. Il a été l'occasion de mettre en évidence comment le bien-fondé d'une approche morphologique couplée à une analyse en échelle nous ont permis d'extraire l'information relative à la taille, dans un écho rétrodiffusé d'une cible immergée et insonifiée par une onde ultrasonore / The necessary scale-based representation of the world leads us to explain why the wavelet theory is the best suited formalism. Its performances are compared to other tools: R/S analysis and empirical modal decomposition method (EMD). The great diversity of analyzing bases of wavelet theory leads us to propose a morphological approach of the analysis. The study is organized into three parts. The first chapter is dedicated to the constituent elements of wavelet theory. Then we will show the surprising link existing between recurrence concept and scale analysis (Daubechies polynomials) by using Pascal's triangle. A general analytical expression of Daubechies' filter coefficients is then proposed from the polynomial roots. The second chapter is the first application domain. It involves edge plasmas of tokamak fusion reactors. We will describe how, for the first time on experimental signals, the Hurst coefficient has been measured by a wavelet-based estimator. We will detail from fbm-like processes (fractional Brownian motion), how we have established an original model perfectly reproducing fBm and fGn joint statistics that characterizes magnetized plasmas. Finally, we will point out the reasons that show the lack of link between high values of the Hurst coefficient and possible long correlations. The third chapter is dedicated to the second application domain which is relative to the backscattered echo analysis of an immersed target insonified by an ultrasonic plane wave. We will explain how a morphological approach associated to a scale analysis can extract the diameter information
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Evaluating Improvisation As A Technique For Training Pre-service Teachers For Inclusive ClassroomsBecker, Theresa 01 January 2012 (has links)
Improvisation is a construct that uses a set of minimal heuristic guidelines to create a highly flexible scaffold that fosters extemporaneous communication. Scholars from diverse domains: such as psychology, business, negotiation, and education have suggested its use as a method for preparing professionals to manage complexity and think on their feet. A review of the literature revealed that while there is substantial theoretical scholarship on using improvisation in diverse domains, little research has verified these assertions. This dissertation evaluated whether improvisation, a specific type of dramatic technique, was effective for training pre-service teachers in specific characteristics of teacher-child classroom interaction, communication and affective skills development. It measured the strength and direction of any potential changes such training might effect on pre-service teacher’s self-efficacy for teaching and for implementing the communication skills common to improvisation and teaching while interacting with student in an inclusive classroom setting. A review of the literature on teacher self-efficacy and improvisation clarified and defined key terms, and illustrated relevant studies. This study utilized a mixed-method research design based on instructional design and development research. Matched pairs ttests were used to analyze the self-efficacy and training skills survey data and pre-service teacher reflections and interview transcripts were used to triangulate the qualitative data. Results of the t-tests showed a significant difference in participants’ self-efficacy for teaching measured before and after the improvisation training. A significant difference in means was also measured in participants’ aptitude for improvisation strategies and for self-efficacy for their implementation pre-/post- training. Qualitative results from pre-service teacher class iv artifacts and interviews showed participants reported beneficial personal outcomes as well as confirmed using skills from the training while interacting with students. Many of the qualitative themes parallel individual question items on the teacher self-efficacy TSES scale as well as the improvisation self-efficacy scale CSAI. The self-reported changes in affective behavior such as increased self-confidence and ability to foster positive interaction with students are illustrative of changes in teacher agency. Self-reports of being able to better understand student perspectives demonstrate a change in participant ability to empathize with students. Participants who worked with both typically developing students as well as with students with disabilities reported utilizing improvisation strategies such as Yes, and…, mirroring emotions and body language, vocal prosody and establishing a narrative relationship to put the students at ease, establish a positive learning environment, encourage student contributions and foster teachable moments. The improvisation strategies showed specific benefit for participants working with nonverbal students or who had commutation difficulties, by providing the pre-service teachers with strategies for using body language, emotional mirroring, vocal prosody and acceptance to foster interaction and communication with the student. Results from this investigation appear to substantiate the benefit of using improvisation training as part of a pre-service teacher methods course for preparing teachers for inclusive elementary classrooms. Replication of the study is encouraged with teachers of differing populations to confirm and extend results.
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