• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 2
  • 1
  • 1
  • Tagged with
  • 9
  • 9
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 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.
1

Extensões de cenários de Branas com defeitos do tipo corda em seis dimensões / Extension of brane scenarios with stringy deffects in six dimensions

Araújo, Júlio César Brasil de January 2012 (has links)
ARAÚJO, Júlio César Brasil de. Extensões de cenários de Branas com defeitos do tipo corda em seis dimensões. 2012. 52 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by francisco lima (admir@ufc.br) on 2014-07-02T17:02:38Z No. of bitstreams: 1 2012_dis_jcdearaujo.pdf: 375967 bytes, checksum: 01abb06adcc382168180a8e7c755d8fc (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2014-08-06T20:43:37Z (GMT) No. of bitstreams: 1 2012_dis_jcdearaujo.pdf: 375967 bytes, checksum: 01abb06adcc382168180a8e7c755d8fc (MD5) / Made available in DSpace on 2014-08-06T20:43:37Z (GMT). No. of bitstreams: 1 2012_dis_jcdearaujo.pdf: 375967 bytes, checksum: 01abb06adcc382168180a8e7c755d8fc (MD5) Previous issue date: 2012 / The purpose of this work is to show an expanse about Gherghetta-Shaposhnikov (GS) scenery through the introduction of a dimensionless parametric in the warped geometry in six dimensions, we suppose which our universe the way that we watch is stood for minkowsk’s 3-brane and the two other are additional dimensions and one of them is compact. In that new model, we are able to achieve the linear process about Einstein’s equation. In order to achieve a perturbation in the metric, so that we are able to locate the equation of motion, consequently finding the massless gravity model. Through these procedures, we have new results about the geometry and physics states in that new scenery. In that new scenery we order the gravity location in a 6-dimensinal geometry, in order to showing an instant where we can find the gravity location, then we get this type of location through an expansion of the GS’s model. / O objetivo deste trabalho é apresentar uma extensão do cenário Gherghetta-Shaposhnikov (GS) através da introdução de um parâmetro adimensional em uma geometria não-fatorizável em seis dimensões, onde supomos que o nosso universo observável é representado por uma 3-brana minkowskiana e as outras duas são dimensões extras, com uma delas compacta. Neste modelo, realizamos o processo de linearização das equações de Einstein fazendo uso de um método perturbativo, a fim de encontrarmos as equações de movimento para em seguida localizarmos o modo-zero gravitacional. A partir desses procedimentos, novos resultados foram obtidos no tocante as propriedades físicas e geométricas desse novo cenário. Com este novo modelo sistematizamos a localização de gravidade em uma geometria 6-dimensional, exibindo um exemplo onde ocorre localização de gravidade e obtendo esse resultado através de uma extensão do modelo GS.
2

Extensões de cenários de Branas com defeitos do tipo corda em seis dimensões / Extension of brane scenarios with stringy deffects in six dimensions

Araújo, Júlio César Brasil de January 2012 (has links)
ARAÚJO, Júlio César Brasil de. Extensões de cenários de Branas com defeitos do tipo corda em seis dimensões. 2012. 52 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-20T17:55:03Z No. of bitstreams: 1 2012_dis_jcbaraujo.pdf: 397232 bytes, checksum: 9f930f4809299b920bbd8ba8bb7f7fa3 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-10-20T21:03:03Z (GMT) No. of bitstreams: 1 2012_dis_jcbaraujo.pdf: 397232 bytes, checksum: 9f930f4809299b920bbd8ba8bb7f7fa3 (MD5) / Made available in DSpace on 2015-10-20T21:03:04Z (GMT). No. of bitstreams: 1 2012_dis_jcbaraujo.pdf: 397232 bytes, checksum: 9f930f4809299b920bbd8ba8bb7f7fa3 (MD5) Previous issue date: 2012 / The purpose of this work is to show an expanse about Gherghetta-Shaposhnikov (GS) scenery through the introduction of a dimensionless parametric in the warped geometry in six dimensions, we suppose which our universe the way that we watch is stood for minkowsk’s 3-brane and the two other are additional dimensions and one of them is compact. In that new model, we are able to achieve the linear process about Einstein’s equation. In order to achieve a perturbation in the metric, so that we are able to locate the equation of motion, consequently finding the massless gravity model. Through these procedures, we have new results about the geometry and physics states in that new scenery. In that new scenery we order the gravity location in a 6-dimensinal geometry, in order to showing an instant where we can find the gravity location, then we get this type of location through an expansion of the GS’s model. / O objetivo deste trabalho é apresentar uma extensão do cenário Gherghetta-Shaposhnikov (GS) através da introdução de um parâmetro adimensional em uma geometria não-fatorizável em seis dimensões, onde supomos que o nosso universo observável é representado por uma 3-brana minkowskiana e as outras duas são dimensões extras, com uma delas compacta. Neste modelo, realizamos o processo de linearização das equações de Einstein fazendo uso de um método perturbativo, a fim de encontrarmos as equações de movimento para em seguida localizarmos o modo-zero gravitacional. A partir desses procedimentos, novos resultados foram obtidos no tocante as propriedades físicas e geométricas desse novo cenário. Com este novo modelo sistematizamos a localização de gravidade em uma geometria 6-dimensional, exibindo um exemplo onde ocorre localização de gravidade e obtendo esse resultado através de uma extensão do modelo GS.
3

Aspects of electric-magnetic dualities in maximal supergravity

Lekeu, Victor 18 June 2018 (has links) (PDF)
This thesis is devoted to various aspects of electric-magnetic duality and its gravitational generalization, with an emphasis on the case of maximal supergravity. It is divided into three parts.In the first part, we review the symmetries of maximal supergravity in various dimensions, with a particular focus on the exceptional ``hidden" symmetries that appear upon toroidal dimensional reduction of eleven-dimensional supergravity. Two new results are obtained. First, we prove in detail that these hidden symmetries appear if and only if the Chern-Simons coupling of the eleven-dimensional theory takes the value predicted by supersymmetry. Second, we obtain a manifestly E7(7)-invariant formula for the entropy of non-extremal black holes in four-dimensional N = 8 supergravity.The second part of the thesis concerns the gaugings of extended supergravities in four dimensions. We first show that the embedding tensor formalism does not allow for deformations that cannot be reached by working with the usual Lagrangian in the duality frame picked by the embedding tensor. We then examine through BRST methods the deformations of a large class of non-minimally coupled scalars and abelian vector fields in four dimensions, of which ungauged supergravities offer a prime example. We prove that all local deformations of these models which modify the gauge transformations are of the usual Yang-Mills type, i.e. correspond to the gauging of some rigid symmetries of the undeformed theory. Combined with the first result, this shows that the embedding tensor formalism correctly captures the most general local deformations of these theories.In the third part, we construct self-contained action principles for several types of free fields in six dimensions, whose field strengths satisfy a self-duality condition. These fields are motivated by two considerations. First, their existence allows for a remarkable geometric interpretation of the electric-magnetic duality symmetries of vector fields and linearized gravity in four dimensions. Second, they appear in the spectrum of the chiral N = (4,0) and N = (3,1) ``exotic supergravities" in place of the usual metric. The free action and supersymmetry transformations for those theories are explicitly constructed. We also check that they reduce to linearized maximal supergravity in five dimensions, thus completing the picture of higher-dimensional parents of N = 8 supergravity, at least at the free level. Along the way, we also generalize previous works on linearized supergravity by other authors, in which the graviton and its dual appear on the same footing at the level of the action.We conclude with some open questions, perspectives for future work, and a series of technical appendices. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
4

Utilizing an Instructional Intervention in Aquatics: An Experimental Study for Improving Wellness Awareness in Adults

Mastel, Felisa Fayette January 2021 (has links)
The medical community recognizes the importance of regular, vigorous exercise. The evidence is indeed overwhelming in support of physical fitness for the prevention of disease and disability; yet nearly 80% of the population does not exercise enough to produce a health benefit (CDC, 2018). Thus, it is necessary to find a way to assist individuals to increase an awareness concerning physical fitness and furthermore, overall wellness awareness. This quantitative study?s instructional intervention treatment interlaced the six dimensions of wellness and Knowles andragogy interwoven within a single activity; in this case water exercise. Hence, the purpose of this study was to assess if adult participation in aquatic exercise classes results in increased awareness, longer lasting self-reported behavioral choices regarding the six dimensions of wellness. This study utilized a split-plot (mixed) factorial ANOVA with two treatment groups (experimental and control) and three occasions of measurements. Furthermore, this study?s assessment was a pretest, posttest 1, and posttest 2 wellness inventory to explore what changes adults perceived throughout the water exercise course and three weeks later. The research explored participants awareness based on teaching and learning plans that intertwined Knowles? (2015) andragogy with the depth and breadth of the wellness dimensions while participating in water exercise. Hence, participants gained an awareness of each wellness dimension. In this research the six dimensions of wellness is: physical, social, emotional, intellectual, environmental, and spiritual wellness. The six dimensions of wellness is an approach to life. It is how a person interacts with their surroundings. Thus, physical fitness is a portion of one?s whole wellness. But introducing the six dimensions into one activity demonstrated an awareness of overall wellness. This study was a step in the right direction as it confirmed adults? increased awareness concerning overall wellness interwoven with Knowles andragogy while participating in water exercise.
5

La localisation spatiale d'outils chirurgicaux par systèmes électromagnétiques alternatifs. Applications et domaines de validité des modélisations numériques

PAILLE, Joffrey 15 March 2004 (has links) (PDF)
Les localisateurs magnétiques sont les seuls systèmes de localisation spatiale à permettre une localisation intra-corporelle. Cependant, les performances de ces systèmes sont fréquemment dégradées dans des conditions « normales » d'utilisation. Les erreurs constatées, de l'ordre de plusieurs millimètres pour les plus significatives, sont notamment provoquées par la présence de matériaux métalliques dans la zone de fonctionnement du localisateur. Ces matériaux engendrent des perturbations électromagnétiques qui modifient les valeurs du champ généré par les sources magnétiques du localisateur. Nous présentons un modèle numérique des phénomènes d'induction électromagnétiques créés dans des milieux conducteurs et/ou magnétiques avec la méthode des éléments finis, utilisant le logiciel FluxExpert. Deux techniques numériques différentes ont été mises en œuvre et comparées. Les résultats obtenus ont été validés. La cohérence et la complémentarité des domaines de validité ont été démontrées.
6

ExtensÃes de cenÃrios de Branas com defeitos do tipo corda em seis dimensÃes. / Extension of brane scenarios with stringy deffects in six dimensions.

JÃlio CÃsar Brasil de AraÃjo 27 February 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O objetivo deste trabalho à apresentar uma extensÃo do cenÃrio Gherghetta-Shaposhnikov (GS) atravÃs da introduÃÃo de um parÃmetro adimensional em uma geometria nÃo-fatorizÃvel em seis dimensÃes, onde supomos que o nosso universo observÃvel à representado por uma 3-brana minkowskiana e as outras duas sÃo dimensÃes extras, com uma delas compacta. Neste modelo, realizamos o processo de linearizaÃÃo das equaÃÃes de Einstein fazendo uso de um mÃtodo perturbativo, a fim de encontrarmos as equaÃÃes de movimento para em seguida localizarmos o modo-zero gravitacional. A partir desses procedimentos, novos resultados foram obtidos no tocante as propriedades fÃsicas e geomÃtricas desse novo cenÃrio. Com este novo modelo sistematizamos a localizaÃÃo de gravidade em uma geometria 6-dimensional, exibindo um exemplo onde ocorre localizaÃÃo de gravidade e obtendo esse resultado atravÃs de uma extensÃo do modelo GS. / The purpose of this work is to show an expanse about Gherghetta-Shaposhnikov (GS) scenery through the introduction of a dimensionless parametric in the warped geometry in six dimensions, we suppose which our universe the way that we watch is stood for minkowskâs 3-brane and the two other are additional dimensions and one of them is compact. In that new model, we are able to achieve the linear process about Einsteinâs equation. In order to achieve a perturbation in the metric, so that we are able to locate the equation of motion, consequently finding the massless gravity model. Through these procedures, we have new results about the geometry and physics states in that new scenery. In that new scenery we order the gravity location in a 6-dimensinal geometry, in order to showing an instant where we can find the gravity location, then we get this type of location through an expansion of the GSâs model.
7

Aspectos gerais do confinamento de campos em mundos brana nÃo fatorizÃveis de seis dimensÃes com enfoque na localizaÃÃo de fÃrmions de Dirac, Rarita-Schwinger e Elko / General aspects of fields localization in six dimensional warped braneworld models with emphasis in the Dirac, Rarita-Schwinger and Elko fermions.

Davi Monteiro Dantas 20 July 2016 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / As teorias de dimensÃes extras tem aplicaÃÃo em diversos ramos de FÃsica de altas energias, auxiliando no entendimento do problema de hierarquia de FÃsica de PartÃculas, nos problemas de matÃria escura e energia escura, alÃm da explicaÃÃo de novas partÃculas. O objetivo desta tese à apresentar aspectos gerais da localizaÃÃo de campos em geometrias de mundo brana nÃo fatorizÃveis warped em seis dimensÃes (6D), onde destacaremos o confinamento de campos fermiÃnicos. Iniciaremos apresentando os modelos 6D espessos e regulares desenvolvidos pelo grupo de Teoria de Campos da UFC e faremos um comparativo destes com outros modelos finos ou nÃo regulares da literatura. Compararemos tambÃm as diferenÃas que ocorrem do confinamento de campos de 5D para 6D. AlÃm disso, a localizaÃÃo dos campos bosÃnicos (gravidade, campo escalar e campo de calibre vetorial) em 6D serà tambÃm discutida. Observaremos que o modo zero da gravidade serà responsÃvel por reproduzir a lei de Newton em nosso mundo 4D. Para o tema central do confinamento de fÃrmions, detalharemos os resultados dos artigos publicados durante meu doutorado. Demonstraremos que à necessÃrio o uso de um acoplamento mÃnimo com um campo de calibre tanto para o espinor de Dirac como para o de Rarita-Schwinger em 6D, apontaremos diferentes escolhas de calibre para os diferentes modelos abordados. Seguindo, exibiremos o espinor Elko. Este espinor tem dimensÃo canÃnica de massa um em 4D (dimensÃo de massa dois em 6D), sendo um autoespinor do operador de conjugaÃÃo de carga de dual helicidade e um candidato natural à matÃria escura. Verificaremos que o Elko necessita de um acoplamento exÃtico para seu confinamento em 6D. AlÃm disso, trataremos de assuntos correlacionados, como as correÃÃes da lei de Coulomb para modelos em dimensÃes extras. Outro assunto presente na tese serà a aplicaÃÃo do conceito de Entropia Configuracional para delimitar os parÃmetros de modelos 6D.
8

A Survey of Wellness Programs in Junior and Community Colleges in the United States

Vastine, Paula Haynes 08 1900 (has links)
This study is concerned with the problem of determining the types and characteristics of wellness programs presently offered by selected junior and community colleges throughout the United States. The purposes include (1) the investigation of the extent to which the six dimensional scheme of wellness, as developed by William Hettler, M. D. [Family and Community Health, May, 1980], has been implemented on the campuses of junior and community colleges and (2) an exploration of the validity of Hettler's model of wellness for these institutions. The study population sample is the membership list of the junior and community college section of the American College Health Association, which is a multidisciplinary professional organization for university and college health administrators. The specially designed survey instrument produced a 73 per cent response return. Response frequencies and percentages were gathered to show the current and anticipated prevalence of different types of wellness programs and the current and anticipated management related characteristics of wellness offerings in these college settings. Several open-ended questions also produced narrative respondent opinions.
9

Étude et réalisation d'un système de localisation en six dimensions pour la chirurgie assistée par ordinateur

Chassat, Fabrice 26 March 2001 (has links) (PDF)
La plupart des Gestes Médicaux-Chirurgicaux Assistés par Ordinateur (G.M.C.A.O.) nécessitent l'utilisation d'un localisateur en six-dimensions. Il s'agit d'un système permettant de déterminer et de suivre la position et l'orientation de corps rigides constitués de marqueurs dans l'espace. De nombreux localisateurs ont été utilisés en chirurgie. Très peu de systèmes sont dédiés spécifiquement à la chirurgie ainsi ils ne répondent pas entièrement de façon satisfaisante aux contraintes du domaine. Nous présentons dans cette thèse, une approche originale de la localisation. A partir d'une étude des applications chirurgicales utilisant un localisateur, nous avons défini un ensemble de critères qualitatifs (encombrement, poids, forme) et quantitatifs en particulier sur la précision pour laquelle un protocole générique d'évaluation des localisateurs pour la chirurgie est proposé. Ces critères nous ont conduit à proposer une évolution des principaux systèmes utilisés aujourd'hui (les localisateurs optiques) afin de les rendre totalement adaptés aux besoins du domaine. En particulier, il est apparu que le coût, la précision et l'ergonomie globale des systèmes existants bien que satisfaisantes dans la plupart des cas étaient insuffisantes pour des applications exigeantes. Nous avons étudié et nous détaillons dans cette thèse deux prototypes permettant de répondre aux problèmes posés par le coût, la précision et surtout l'ergonomie. A partir de la base commune d'un localisateur par stéréovision passive repérant des marqueurs ponctuels, nous proposons une évolution originale basée sur la localisation et l'identification de marqueurs linéaires par le rapport de Thalès pour améliorer la visibilité des cibles. Enfin nous proposons deux concepts très innovants de localisation répondant à l'inconvénient majeur des systèmes optiques qui doivent avoir une ligne de vue entre les caméras et les marqueurs libre de tout obstacle.

Page generated in 0.1023 seconds