Includes amendments (8 p.) in pocket / Bibliography: leaves 306-331 / iv, 349 leaves, [34] leaves of plates : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1988

Thesis (D.Min.)--Dallas Theological Seminary, 2008. / Includes abstract. Description based on print version record. Includes bibliographical references (leaves 188-197).

Thesis (D. Min.)--Dallas Theological Seminary, 2008. / Includes abstract. Includes bibliographical references (leaves 188-197).

Thesis (D.Min.)--Dallas Theological Seminary, 2008. / Includes abstract. Includes bibliographical references (leaves 188-197).

Thesis (B.A.)--Haverford College, Dept. of Philosophy, 2005. / Includes bibliographical references.

Texte remanié de: Th. doct.--Sc. de l'éduc.--Aix-Marseille 1, 1996. Titre de soutenance : La régulation du projet professionnel dans la formation en alternance des cadres : une approche herméneutique. / Bibliogr. p. 127-133.

In this thesis I discuss probes of small spatial scales around young stars and protostars and around the supermassive black hole at the galactic center. I begin by describing adaptive optics-fed infrared spectroscopic studies of nascent and newborn binary systems. Binary star formation is a significant mode of star formation that could be responsible for the production of a majority of the galactic stellar population. Better characterization of the binary formation mechanism is important for better understanding many facets of astronomy, from proper estimates of the content of unresolved populations, to stellar evolution and feedback, to planet formation. My work revealed episodic accretion onto the more massive component of the pre-main sequence binary system UY Aur. I also showed changes in the accretion onto the less massive component, revealing contradictory indications of the change in accretion rate when considering disk-based and shock-based tracers. I suggested two scenarios to explain the inconsistency. First, increased accretion should alter the disk structure, puffing it up. This change could obscure the accretion shock onto the central star if the disk is highly inclined. Second, if accretion through the disk is impeded before it makes it all the way onto the central star, then increased disk tracers of accretion would not be accompanied by increased shock tracers. In this case mass must be piling up at some radius in the disk, possibly supplying the material for planet formation or a future burst of accretion. My next project focused on characterizing the atmospheres of very low-mass companions to nearby young stars. Whether these objects form in an extension of the binary-star formation mechanism to very low masses or they form via a different process is an open question. Different accretion histories should result in different atmospheric composition, which can be constrained with spectroscopy. I showed that 3-4 μm spectra of a sample of these objects with effective temperatures greater than 1500 K are similar to the spectra of older more massive brown dwarfs at the same temperature, in contrast to objects at 1000 K that exhibit distinct L-band SEDs. The oldest object in my sample of young companions, 50 My old CD-35 2722 B, appears redder than field dwarfs with similar spectral type based on 1-2.5 μm spectra. This could indicate reduced cloud opacity compared to field dwarfs at the same temperature. I also present work to better understand the supermassive blackhole at the center of our Galaxy. Astrometric monitoring of stellar orbits about the blackhole have been used to sketch the gravitational potential, revealing 4 x 10⁶ M_⊙ within a radius of 40 AU. Further constraints on the gravitational potential, and the detection of post-Newtonian effects on the stellar orbits, will require improved astrometric precision. Currently confusion noise in the crowded central cluster limits astrometric precision. Increased spatial resolution can alleviate confusion noise. Dual field phase referencing on large-aperture infrared interferometers provides the sensitivity needed to observe the Galactic center, providing the fastest route to increased spatial resolution. I present simulations of dual-field phase referencing performance with the Keck Interferometer and with the VLTI GRAVITY instrument, to describe the potential contributions each could make to Galactic center stellar astrometry. I demonstrate that the near-future GRAVITY instrument at the VLTI will have a large impact on the ability to precisely track the paths of stars orbiting there, as long as a star with K-band apparent magnitude less than 20 exists within 70 milliarcseconds of the blackhole. Many of the stars orbiting the blackhole are in a post-main sequence wind phase. The wind from these stars is feeding an accretion flow falling onto the blackhole. This flow is radiatively inefficient, producing only 10⁻⁸ times the Eddington limit. Thus our relative proximity to the center of our own Galaxy, provides the opportunity to study a low-luminosity accretion mode that would be difficult or impossible to observe in more remote galaxies. Variable emission from the accretion flow arises from very deep within the flow and could be used to reveal the physics of the accretion process. Characterizing the variability is challenging because all wavelength regimes from radio through X-ray are affected by the process(es) that gives rise to the variations. I report observations of variability at wavelengths that are difficult or challenging to observe from the ground using the SPIRE instrument onboard the Herschel Space Observatory. My work provides the first constraints on the flux of the accretion flow at 250 μm. Variations at 500, 350, and 250 μm observed with Herschel exhibit typical amplitudes similar to the variations observed at 1300 μm from the ground, but the amplitude distribution of flux variations observe with Herschel does not exhibit a tail to large amplitudes that is seen at 1300 μm. This could suggest a connection between large-amplitude mm/submillimeter variations and X-ray activity, since no increased X-ray activity was observed during our Herschel monitoring.

L'objectif principal de ce travail était d'étudier les mécanismes perceptivo-moteurs qui sous-tendent l'apprentissage d'une tâche complexe. L'exemple choisi dans le présent manuscrit est celui de l'atterrissage et plus particulièrement de la phase d'approche d'un avion vers la piste. Cette manoeuvre est une phase de vol critique qui nécessite de nombreuses heures de formation et d'entraînement. Notre objectif était donc d'étudier, en s'appuyant sur l'approche écologique de la perception et de l'action, les différents moyens permettant de faciliter l'apprentissage de la phase d'approche. La première partie de ce travail détaille les différents aspects techniques permettant d'appréhender la procédure d'atterrissage puis dresse l'état actuel des connaissances sur la conception écologique de l'apprentissage. La partie centrale de cette thèse constitue le socle de notre démarche expérimentale et repose sur l'utilisation de la réalité virtuelle. Les manipulations effectuées pour améliorer l'apprentissage de la phase d'approche consistaient dans un premier temps, à ajouter une information artificielle dans l'environnement virtuel (Expériences 1 et 2) afin de faciliter la détection des informations utiles au contrôle de l'action. Les résultats de ces premières études montrent que l'apprentissage peut être amélioré à condition d'afficher l'information artificielle à la demande de l'apprenant. Par ailleurs, des tests de transferts réalisés à la fin de l'expérience 2 révèlent aussi que les participants apprennent à utiliser des informations visuelles différentes. L'objectif de notre dernière expérience (Expérience 3) était donc de manipuler l'aménagement des conditions de pratique pour éduquer l'attention de l'apprenant vers une information particulière,choisie par l'expérimentateur. Pris dans leur ensemble, ces résultats permettent de discuter des différents processus qui sous-tendent l'acquisition d'une nouvelle habileté perceptivo-motrice. La discussion générale de ce travail évoque notamment les conséquences des différentes manipulations effectuées au cours des trois chapitres expérimentaux sur le mécanisme d'éducation de l'attention et discute du rôle des différentes informations utilisées par les apprenants. Enfin, nous suggérons quelques pistes pratiques en relation avec le domaine de la formation des pilotes pour traduire de façon appliquée les résultats obtenus lors de ce travail. / The main objective of this work was to study perceptual-motor mechanisms underlying the learning of a complex task. The task chosen concerns the particular phase of plane landing called the approach phase. This maneuver is a critical phase of fliight and requires many hours of training. Our aim was to study ways to facilitate the learning of the approach phase from an ecological approach to perception andaction. The first part of this work details the technical aspects involved in understanding the landing procedure and describes the current state of knowledge on the ecological approach of learning. The second part of this thesis is the foundation ofour experimental work which was based on the use of virtual reality. In order toimprove the learning of the approach phase, the manipulation consisted of adding artificial information in the virtual environment (Experiment 1 and 2) which facilitated the detection of useful information to control action. The results of these studies show that learning can be improved if artificial information display is self-controlledby the participant. In addition, transfer tests performed at the end of Experiment 2revealed that the participants came to rely on different visual information. The aimof our last experiment (Experiment 3) was to vary the practice conditions in orderto educate the attention of the participants towards specific information, selectedby the experimenter. In sum, these results allow us to discuss the different processes underlying the acquisition of a new perceptual-motor skill. In the general discussion we refer to the consequences of the various operations performed during the three experimental chapters on the mechanism of education of attention and discuss therole of the various information used by the participants. Finally, we suggest several practical applications potentially useful for the improvement of pilots training

Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-29T13:06:26Z No. of bitstreams: 1 Dissertacao_Claudio Nascimento.pdf: 681069 bytes, checksum: 13db7f22b028d186cb18d935b0f6476f (MD5) / Approved for entry into archive by Maria Auxiliadora Lopes(silopes@ufba.br) on 2013-06-11T13:17:41Z (GMT) No. of bitstreams: 1 Dissertacao_Claudio Nascimento.pdf: 681069 bytes, checksum: 13db7f22b028d186cb18d935b0f6476f (MD5) / Made available in DSpace on 2013-06-11T13:17:41Z (GMT). No. of bitstreams: 1 Dissertacao_Claudio Nascimento.pdf: 681069 bytes, checksum: 13db7f22b028d186cb18d935b0f6476f (MD5) Previous issue date: 2003 / Este estudo apresenta reflexões sobre Itinerâncias de professores, construção de sentidos e autorias de formação continuada. Busquei conhecer o que querem os professores ante a formação continuada; suas percepções e compreensões de/na formação pessoal/profissional. Um exercício interpretativo e de (re)criação teórica nos cenários de formação das escolas particulares de ensino básico e do Sinpro-Ba - Sindicato dos Professores no Estado da Bahia. Este trabalho foi constituído a partir de inspirações qualitativas, hermenêutica e fenomenológica crítica, como postura e recurso metodológico na interpretação das narrativas dos professores em contraste com as metanarrativas generalistas - das macro-políticas, do pensamento moderno cartesiano, dos ordenamentos legais referentes a atual reforma do ensino - ora hegemônicas no campo da formação docente. Nessa perspectiva os professores participantes da Pesquisa demonstram a emergência de várias polifonias, sentidos e significados de formação: um conceito complexo, multirreferencial... Vozes contextualizadas, interpretativas, instituintes de outro ethos de formação docente.Também constitutivas do professor-ator-autor. / Salvador

La « médiaction » se définit comme une action qui se met en place par et grâce aux outils de l’Internet, nommés « médium », qui dans une position de tiers inclus, dans un dispositif de formation ou d’éducation, proposent des médiations cognitives dans un espace spatio-temporel en mouvement. Mise en oeuvre dans des systèmes formatifs, La « médiaction » permet, grâce à la fonction d’accompagnement médiactif, d’imaginer des systèmes formatifs qui alternent la présence (le physique) et la distance (le virtuel).Nous sommes ici dans une nouvelle forme d’accompagnement, qui se situe à distance dans un premier temps, mais principalement dans l’entre-deux avec la présence, dans un deuxième. La particularité de cet accompagnement à distance réside dans le fait que les dispositifs nous positionnent dans des situations de« dé-temporalisation » et de « dé-spatialisation ». À forme nouvelle d’accompagnement, compétences nouvelles et celles de l’accompagnateur médiactif doivent se comprendre dans un positionnement d’articulation entre trois phases d’accompagnements, mais aussi quatre formes d’alternances et cinq niveaux d’interactions.Les dispositifs qui sont mis en place en alternances présencielle/distancielles font appel à des processus médiatisés comme l’Internet et donc aux outils qui permettent d’y accéder. Néanmoins, les acteurs de ces dispositifs ne se dirigent ils pas vers un objet (l’ordinateur entre autres), par la connaissance et le désir,l’envie de découverte, en même temps qu’ils visent sa propre intégration ? Le comportement du sujet-acteur, les choix qu’il fait, les possibilités techniques qu’il a (ordinateur ou pas) ne définissent-ils pas l’orientation de celui-ci vers l’objet et les modalités mises en exergue par l’action dans le système de formation en présenciel/distanciel ? C’est peut-être par la mise en oeuvre d’un processus d’appropriation par l’action qu’apparait une forme de liberté d’expression. Ce processus se dénommerai talors l’« approaction ».Je me suis basé sur la théorie tripolaire de la formation pour mettre en oeuvre ces dispositifs. Trois pôles indissociables de l’autoformation existentielle au coeur desquels les acteurs se trouvent un rôle éducatif et formatif en « coconstruisant» des savoirs. Le passage permanent entre la « dé-spacialisation »et la « dé-temporalisation » pourrait alors nous donner la possibilité d’imaginer un quatrième pôle qui situerait les autres (hétéro) alternativement dans la présence et la distance, ce qui ouvrirait la porte à une « tétrapolarisation » de la formation, qui se révolutionnerait dans un système « médiasphèrique », espace de l’accompagnement médiactif. / The « mediaction » is defined as an action that positions itself by and through the tools of the Internet, the so-called « medium », which as an included third part, in a formative or educational operation, offers a cognitive mediation in a space-time in motion. Implemented in formative systems, it allows, thanks to the fuction of mediactive support, to imagine formative systems that alternate between presence (physical) and distance (virtual). We are here in presence of a new kind of guidance, which is distant at first, but mainly in-between presence and distance, in a second time. The particularity of this distant guidance lies in the fact that the operations position us in situations of « de-temporality » and « despatialization». A new form of guidance requires new skills and those of the mediactive supervisor must be understood in a position of articulation between the three phases of guidance, but also the four types of alternations and the five levels of interaction. Operations that are introduced, alternating presence/distance, involve mediated processes such as the Internet and hence the tools to access them. However, are actors in these operations not converging towards an object (the computer among others), through the knowledge and desire, the desire for discovery, in the same time as they are aiming at its own integration ? Do the subject-actor's behavior, the choices that he makes, technical possibilites (computer or not) not define his direction towards the object and terms highlighted by the action in the formative system alterning between presence/distance? It may be through the implementation of a process of appropriation through action, that emerges a new kind of freedom of expression. This process would then be called « approaction ».I relied on the tripolar formative theory to implement these learning operations. Three inseparable pillars of the existential self-learning at the core of which actors are involved in educational and formative knowledge« co-construction ». The permanent gateaway between the « despatialization» and « de-temporality » could then allow us to imagine a fourth pillar that would position the others (hetero) alternately in the presence and distance, opening the door to a « tetrapolarised »formation, that would revolutionize itself in a « mediaspheric » system,space of the mediactive guidance.