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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.
1

Aproximación metodológica a la obtención de modelos de percepción de molestias a partir de parámetros psicoacústicos en vehículos ferroviarios. Aplicación a trenes de alta velocidad

Mateo Martínez, Begoña 07 January 2016 (has links)
[EN] Comfort on board is, nowadays, one of the main reasons for the choice of transport means. Therefore, offering greater comfort is an advantage against other modes of mobility and the competition brought about by liberalization of rail passenger transport. Noise is a key factor influencing passenger comfort. Therefore, in the late nineties, the first relevant acoustic comfort studies about high-speed vehicles began to appear. Although most studies focus mainly on the physical characterization, they have made some progress on trying to relate the interior noise and the passenger comfort. The main objective of this research is to conduct a methodological approach to obtaining a psychoacoustic model, in order to predict the level of discomfort of passengers in conditions of commercial circulation, and make a comparison between different high-speed rail vehicles in terms of sound quality. For this purpose, it was necessary to define an experimental methodology to obtain objective parameters of the background noise, as well as subjective measures of perception. In particular, for the calculation of objective measures, this study develops a procedure to measure sound inside high-speed vehicles traveling at commercial speed, that allows their psychoacoustical comparison. The field study has identified the psychoacoustic variables that best describe the background noise, and how they vary according to their location within the vehicle. To measure the perception, a methodology to assess the level of annoyance of representative sounds has been defined. This methodology has been validated as a result of the study, obtaining a high reliability in the measurement of discomfort levels. The experimental methodology was applied in a field study, where the sound within six high-speed vehicles traveling at commercial speed was recorded. That field study allowed to record forty-six sounds that were subsequently measured in their level of discomfort by passengers. In order to obtain a model to predict the level of annoyance, different psychoacoustic variables were analyzed: A weighted pressure level, loudness, sharpness and roughness of the sounds, along with the level of annoyance perceived by multiple linear regression. The model obtained has a predictive capacity of 90.8%. Moreover, the research includes a comparison of the level of discomfort and a psychoacoustic characterization of the vehicles that were part of the field study. / [ES] El confort a bordo es, hoy en día, uno de los motivos clave de la elección del medio de transporte. Por tanto, ofrecer una mayor comodidad es una ventaja competitiva a la hora de presentar una oferta diferenciada ante otros modos de movilidad y ante la competencia que aparecerá con la liberalización del transporte de viajeros por ferrocarril. El ruido es clave como factor que influye en el confort del pasajero. Por ello, a finales de los años noventa, comienzan a aparecer los primeros estudios relevantes sobre confort acústico de vehículos de alta velocidad. Aunque la mayor parte de los estudios se centran principalmente en la caracterización física, se han realizado algunos avances en intentar relacionar el ruido interior con el confort del pasajero. El objetivo principal de la presente investigación es realizar una aproximación metodológica a la obtención de un modelo psicoacústico que permita predecir el nivel de molestias de los pasajeros en condiciones de circulación comerciales, así como realizar una comparativa de diferentes vehículos ferroviarios de alta velocidad en cuanto a su calidad sonora. Con este objetivo, ha sido necesaria la definición una metodología experimental para la obtención de parámetros objetivos del ruido de fondo así como de medidas subjetivas de la percepción del pasajero. En concreto, para el cálculo de medidas objetivas, se ha definido un procedimiento de medida del sonido en el interior de vehículos de alta velocidad circulando a velocidad comercial que permita la caracterización psicoacústica para su comparativa. El estudio de campo realizado ha permitido identificar las variables psicoacústicas que mejor describen el ruido de fondo y conocer como varían en función de su localización dentro del vehículo. Para la medida de la percepción se ha definido una metodología de evaluación del nivel de molestia de los sonidos representativa de la percepción del pasajero. Esta metodología ha sido validada como resultado del estudio, obteniendo una elevada fiabilidad en la medida del nivel de molestia. La metodología experimental ha sido aplicada en un estudio de campo donde se registró el sonido en el interior de seis vehículos de alta velocidad circulando a velocidad comercial. El estudio de campo permitió registrar cuarenta y seis sonidos que posteriormente fueron valorados por pasajeros en cuanto a su nivel de molestia. Con el objetivo de obtener un modelo de predicción del nivel de molestia, las variables psicoacústicas: nivel de presión sonora ponderado A, loudness, sharpness y roughness de los sonidos registrados fueron analizadas junto con el nivel de molestia percibido mediante un análisis de regresión lineal múltiple. El modelo obtenido presenta una capacidad de predicción del 90,8%. Adicionalmente, se realizó una comparativa de los vehículos que formaron parte del estudio de campo en cuanto a su nivel de molestia y su caracterización psicoacústica. / [CAT] El confort a bord, és, hui en dia, un dels motius clau de l'elecció del mitjà de transport. Per tant, oferir una major comoditat és un avantatge competitiu a l'hora de presentar una oferta diferenciada front a altres modes de mobilitat i davant la competència que apareixerà amb la liberalització del transport de viatgers per ferrocarril. El soroll és clau com a factor que influeix en el confort del passatger. Per això, a finals dels anys noranta, comencen a aparèixer els primers estudis rellevants sobre confort acústic de vehicles d'alta velocitat. Encara que la major part dels estudis es centren principalment en la caracterització física, s'han realitzat alguns avanços en intentar relacionar el soroll interior amb el confort del passatger. L'objectiu principal de la present recerca és realitzar una aproximació metodològica a l'obtenció d'un model psicoacústic que permeta predir el nivell de molèsties dels passatgers en condicions de circulació comercials, així com realitzar una comparativa de diferents vehicles ferroviaris d'alta velocitat en quant a la seua qualitat sonora. Amb aquest objectiu, ha sigut necessària la definició d'una metodologia experimental per a l'obtenció de paràmetres objectius del soroll de fons, així com les mesures subjectives de la percepció del passatger. En concret, per al càlcul de mesures objectives, s'ha definit un procediment de mesura del soroll a l'interior de vehicles d'alta velocitat circulant a velocitat comercial que permeta la caracterització psicoacústica per a la seua comparativa. L'estudi de camp realitzat a permès identificar les variables psicoacústiques que millor descriuen el soroll de fons i conèixer com varien en funció de la seua localització dins del vehicle. Per a la mesura de la percepció s'ha definit una metodologia d'avaluació del nivell de molèstia dels sons representativa de la percepció del passatger. Aquesta metodologia ha sigut validada com resultat de l'estudi, obtenint una elevada fiabilitat en la mesura del nivell de molèstia. La metodologia experimental ha sigut aplicada en un estudi de camp on es registrà el so a l'interior de sis vehicles d'alta velocitat circulant a velocitat comercial. L'estudi de camp va permetre enregistrar quaranta sis sons que posteriorment foren valorats per passatgers en quant al seu nivell de molèstia. Amb l'objectiu d'obtindre un model de predicció del nivell de molèstia, les variables psicoacústiques nivell de pressió sonora ponderat A, loudness, sharpness i roughness dels sons enregistrats foren analitzades junt amb el nivell de molèstia percebut mitjançant una anàlisi de regressió lineal múltiple. El model obtingut presenta una capacitat de predicció del 90,8%. Addicionalment, es va realitzar una comparativa dels vehicles que formaren part de l'estudi de camp en quant al seu nivell de molèstia i la seua caracterització psicoacústica. / Mateo Martínez, B. (2015). Aproximación metodológica a la obtención de modelos de percepción de molestias a partir de parámetros psicoacústicos en vehículos ferroviarios. Aplicación a trenes de alta velocidad [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59414 / TESIS
2

Sobredentaduras mandibulares retidas por mini implantes: um ensaio clínico randomizado (parte I) / Mandibular overdentures retained by conventional or mini implants: a randomized clinical trial (parte I)

Adriana Barbosa Ribeiro 13 January 2015 (has links)
A retenção de próteses totais removíveis por mini-implantes é uma modalidade de tratamento relativamente recente, com potencial de minimizar o trauma pós-operatório e reduzir custos associados. Este estudo buscou comparar a qualidade de vida relacionada à saúde bucal e satisfacão do paciente, bem como dor e desconforto pós-operatórios, decorrentes da instalação de mini-implantes (dois ou quatro) ou dois implantes de dimensões regulares para a retenção de sobredentaduras mandibulares. Cento e vinte participantes edentados (media etária 59,5±8,5 anos) foram alocados aleatoriamenteem três grupos conforme o tratamento recebido: (GI) quatro mini-implantes, (GII) dois mini-implantes, ou (GIII) dois implantes regulares. Sete dias após a instalação dos implantes, os participantes responderam questões (Escala visualanalógica - EVA de 100 mm) referentes à dor, edema e desconforto durante mastigação, fala e higiene, considerando as experiências vividas durante os períodos avaliados. Antes das intervenções e passados 3 e 6 meses da instalação das sobredentaduras, a qyalidade de vida relacionada à saúde bucal foi avaliada por meio do questionário OHIP-EDENT, e a satisfação analisada por perguntas específicas respondidas emu ma EVA de 100 mm. Os grupos foram comparados por meio de ANOVA para dois fatores ou Equações de Estimação Generalizadas (EEG) (α=0,05). Todos os participantes (GI: 38; GII: 42; GIII: 40) foram analisados após sete dias da instalação dos implantes instalação para dor e desconforto pós-operatório, e 112 responderam às questões sobre qualidade de vida relacionada à saúde bucal e satisfação de paciente. Ao 6º dia, GI sentiu dor significantemente maior que GII e GIII. GI também notou maior dificuldade para a prática de higiene oral que GIII durante o 1º dia. Não houve diferença significante entre os grupos para outras questões e períodos. Os achados para o OHIP-EDENT indicam que tanto os grupos tratados com dois ou quatro mini-implantes levaram a uma maior QVSB, comparados aos implantes convencionais. Aos três e seis meses, encontramos que os três grupos tratados com quatro mini-implantes estavam mais satisfeitos que os que receberam dois implantes convencionais e dois mini-implantes resultaram em valores intermediários. Conclui-se que o uso de quatro mini-implantes induz maior dor pós-operatória ao sexto dia que a inserção de dois mini-implante ou implantes convencionais, bem como higiene oral mais difícil ao primeiro dia. Além disso, o tratamento com sobredentaduras retidas por mini-implantes é comparável ao padrão de tratamento para o edentulismo, de acordo com as perspectivas do paciente. O tratamento por dois ou quatro mini-implantes alcança resultados similares ou mesmo discretamente superiores em termos de qualidade de vida relacionada à saúde bucal ou satisfação do paciente, comparado aos implantes convencionais / The retention of removable dentures by mini-implants is a relatively recent treatment modality, and may lead to minimal postoperative trauma and reduced costs. This study aimed to compare oral health-related quality of life and patient satisfaction, as well as postoperative pain and discomfort, following the insertion of mini-implants (two or four) or two standard-size implants for the retention of mandibular overdentures. One hundred and twenty edentulous participants (mean age 59.5±8.5 years) were randomly allocated into three groups according to received treatment: (GI) four mini-implants, (GII) two mini-implants, or (GIII) two standard implants. Seven days after implant insertion, patients answered questions (100-mm VAS Visual Analog Scale) relating to pain, swelling, and discomfort with chewing, speech and hygiene, considering their experiences during the 1st and 6th day. Before the interventions and after 3 and 6 months following insertion, OHRQoL was evaluated by means of the OHIP-EDENT questionnaire and patient satisfaction was analyzed by a specific questionnaire answered on a 100-mm VAS. Groups were compared by two-way ANOVA or Generalized Estimating Equations (GEE) (α=0.05). All participants (GI: 38; GII: 42; GIII: 40) were analyzed after seven days of postoperative pain and discomfort, and 112 answered questions regarding oral health-related quality of life and patient satisfaction. At the 6th day, GI felt significantly higher pain than GII and GIII. GI also reported more difficulty in performing oral hygiene practices than GIII during the 1st day. There was no significant difference between groups for the other questions and periods. The findings from OHIP-EDENT indicate that both two and four mini-implants led to better OHRQoL, compared to two conventional implants. At three and six months, we found that the group treated with four mini-implants was more satisfied than the two conventional implants and two mini-implants was presented intermediate values. It can be concluded that the use of four mini-implants induces more intense postoperative pain at the 6th day than the insertion of two mini- or conventional fixtures, as well as more difficult oral hygiene on the 1st day. Furthermore, the treatment by mini-implant overdentures is comparable to the standard of care for edentulism, according to the patient perspective. Treatment by either two or four mini-implants achieve similar or even slightly better OHQoL and satisfaction compared to two conventional implants
3

Sobredentaduras mandibulares retidas por mini implantes: um ensaio clínico randomizado (parte I) / Mandibular overdentures retained by conventional or mini implants: a randomized clinical trial (parte I)

Ribeiro, Adriana Barbosa 13 January 2015 (has links)
A retenção de próteses totais removíveis por mini-implantes é uma modalidade de tratamento relativamente recente, com potencial de minimizar o trauma pós-operatório e reduzir custos associados. Este estudo buscou comparar a qualidade de vida relacionada à saúde bucal e satisfacão do paciente, bem como dor e desconforto pós-operatórios, decorrentes da instalação de mini-implantes (dois ou quatro) ou dois implantes de dimensões regulares para a retenção de sobredentaduras mandibulares. Cento e vinte participantes edentados (media etária 59,5±8,5 anos) foram alocados aleatoriamenteem três grupos conforme o tratamento recebido: (GI) quatro mini-implantes, (GII) dois mini-implantes, ou (GIII) dois implantes regulares. Sete dias após a instalação dos implantes, os participantes responderam questões (Escala visualanalógica - EVA de 100 mm) referentes à dor, edema e desconforto durante mastigação, fala e higiene, considerando as experiências vividas durante os períodos avaliados. Antes das intervenções e passados 3 e 6 meses da instalação das sobredentaduras, a qyalidade de vida relacionada à saúde bucal foi avaliada por meio do questionário OHIP-EDENT, e a satisfação analisada por perguntas específicas respondidas emu ma EVA de 100 mm. Os grupos foram comparados por meio de ANOVA para dois fatores ou Equações de Estimação Generalizadas (EEG) (α=0,05). Todos os participantes (GI: 38; GII: 42; GIII: 40) foram analisados após sete dias da instalação dos implantes instalação para dor e desconforto pós-operatório, e 112 responderam às questões sobre qualidade de vida relacionada à saúde bucal e satisfação de paciente. Ao 6º dia, GI sentiu dor significantemente maior que GII e GIII. GI também notou maior dificuldade para a prática de higiene oral que GIII durante o 1º dia. Não houve diferença significante entre os grupos para outras questões e períodos. Os achados para o OHIP-EDENT indicam que tanto os grupos tratados com dois ou quatro mini-implantes levaram a uma maior QVSB, comparados aos implantes convencionais. Aos três e seis meses, encontramos que os três grupos tratados com quatro mini-implantes estavam mais satisfeitos que os que receberam dois implantes convencionais e dois mini-implantes resultaram em valores intermediários. Conclui-se que o uso de quatro mini-implantes induz maior dor pós-operatória ao sexto dia que a inserção de dois mini-implante ou implantes convencionais, bem como higiene oral mais difícil ao primeiro dia. Além disso, o tratamento com sobredentaduras retidas por mini-implantes é comparável ao padrão de tratamento para o edentulismo, de acordo com as perspectivas do paciente. O tratamento por dois ou quatro mini-implantes alcança resultados similares ou mesmo discretamente superiores em termos de qualidade de vida relacionada à saúde bucal ou satisfação do paciente, comparado aos implantes convencionais / The retention of removable dentures by mini-implants is a relatively recent treatment modality, and may lead to minimal postoperative trauma and reduced costs. This study aimed to compare oral health-related quality of life and patient satisfaction, as well as postoperative pain and discomfort, following the insertion of mini-implants (two or four) or two standard-size implants for the retention of mandibular overdentures. One hundred and twenty edentulous participants (mean age 59.5±8.5 years) were randomly allocated into three groups according to received treatment: (GI) four mini-implants, (GII) two mini-implants, or (GIII) two standard implants. Seven days after implant insertion, patients answered questions (100-mm VAS Visual Analog Scale) relating to pain, swelling, and discomfort with chewing, speech and hygiene, considering their experiences during the 1st and 6th day. Before the interventions and after 3 and 6 months following insertion, OHRQoL was evaluated by means of the OHIP-EDENT questionnaire and patient satisfaction was analyzed by a specific questionnaire answered on a 100-mm VAS. Groups were compared by two-way ANOVA or Generalized Estimating Equations (GEE) (α=0.05). All participants (GI: 38; GII: 42; GIII: 40) were analyzed after seven days of postoperative pain and discomfort, and 112 answered questions regarding oral health-related quality of life and patient satisfaction. At the 6th day, GI felt significantly higher pain than GII and GIII. GI also reported more difficulty in performing oral hygiene practices than GIII during the 1st day. There was no significant difference between groups for the other questions and periods. The findings from OHIP-EDENT indicate that both two and four mini-implants led to better OHRQoL, compared to two conventional implants. At three and six months, we found that the group treated with four mini-implants was more satisfied than the two conventional implants and two mini-implants was presented intermediate values. It can be concluded that the use of four mini-implants induces more intense postoperative pain at the 6th day than the insertion of two mini- or conventional fixtures, as well as more difficult oral hygiene on the 1st day. Furthermore, the treatment by mini-implant overdentures is comparable to the standard of care for edentulism, according to the patient perspective. Treatment by either two or four mini-implants achieve similar or even slightly better OHQoL and satisfaction compared to two conventional implants
4

Arts textiles contemporains : quêtes de pertinences culturelles / Contemporary textile arts : searches of cultural relevancies

Crenn, Julie 12 October 2012 (has links)
L’étude propose une vue d’ensemble de la création textile à travers différents prismes puisque nous abordons les pratiques artistiques utilisant les costumes d’époque, la broderie, l’assemblage textile, les cheveux, les tissus traditionnels, la tapisserie ou encore l’art du quilting. Qu’il s’agisse des oeuvres de Yinka Shonibare, Louise Bourgeois, Hassan Musa, Faith Ringgold, Kimsooja ou Tracey Emin, chacun des artistes sélectionnés pour notre étude, propose une recherche visant une pertinence culturelle grâce à l’élaboration d’une pratique plastique où expériences personnelles et collectives s’entremêlent. La pertinence culturelle étant entendue ici comme une reconstruction critique et théorique d’une histoire par l’appropriation de matériaux et/ou de techniques textiles spécifiques. Nous avons opté pour un travail thématique afin d’analyser au mieux ce que nous appelons la scène textile globale. Une première partie propose l’analyse des travaux d’artistes réfléchissant sur l’histoire et la culture noire. Nous étudierons une sélection d’oeuvres mettant en lumière deux traumas : l’esclavage et le colonialisme, ainsi que leurs répercussions actuelles sur la culture et la société. Ainsi les travaux de Faith Ringgold, Yinka Shonibare, Hassan Musa et Maria Magdalena Campos-Pons seront analysés afin de parler de problématiques comme « l’hybridité culturelle », la créolisation, la situation de l’art contemporain africain ou encore la représentation du corps noir dans l’art. Une seconde partie est axée sur les notions d’exil, de diaspora et de l’inconfort induit par le nomadisme, le statut « entre-deux ». Les pratiques de Mona Hatoum, de femmes artistes arabes comme Lalla Essaydi, Shadi Ghadirian ou Ghazel, ainsi que les travaux de Kimsooja, Janine Antoni et Ana de la Cueva nous permettrons d’entrer au coeur d’une scène artistique dont les enjeux critiques nous portent à réfléchir sur la mondialité, dans ses aspects positifs (enrichissement, échange, dialogue) comme négatifs (uniformisation, standardisation, perte des spécificités locales). Grâce au vecteur textile, chacun de ces artistes appréhende le monde et la société d’une manière à la fois poétique, critique et politique. Une troisième partie est dédiée aux artistes (majoritairement des femmes) ayant choisi l’utilisation de techniques textiles traditionnelles comme la broderie, le tissage ou la tapisserie. Avec l’explosion de la scène féministe depuis les années 1970 jusqu’aux travaux actuels, la broderie n’est désormais plus considérée comme un loisir typiquement féminin, mais comme une véritable arme politique. Une arme dirigée vers le machisme, le patriarcat ou encore les inégalités liées au genre. Dans ce cadre, les pratiques d’artistes comme Elaine Reichek, Judy Chicago, Louise Bourgeois, Joana Vasconcelos, Tracey Emin, Ghada Amer, Cathy Burghi, permettront d’aborder la broderie dans l’art contemporain de manière diversifiée et hétérogène. À travers ces différentes analyses, nous observons la déconstruction de la hiérarchie des arts et le fait que l’art textile contemporain apparaît comme un art engagé et pertinent, proposant des perspectives de réflexions riches en lien avec les problématiques du monde actuel. / The study advises an overview of the textile creation in the widest sense because we approach the artistic practices using period costumes, embroidery, textile assembly, hair, traditional fabrics, tapestry or quilting art. That it is about works of Yinka Shonibare, Louise Bourgeois, Hassan Musa, Faith Ringgold, Kimsooja or Tracey Emin, each of the artists chosen for the study, is in search of a cultural relevance within his artistic practice where personal and collective experiences are interwoven. The cultural relevance being understood here as a critical and theoretical reconstruction of a (his)story by the mean of appropriation of specific textile materials and techniques. We opted for a thematic work to analyze at best what we call the global textile scene. A first part proposes the analysis of works from artists who think about Black culture and history. We will study works that shade light on two traumas: Slavery and colonialism, as well as their echoes on nowadays culture and society. So the works of Faith Ringgold, Yinka Shonibare, Hassan Musa and Maria Magdalena Campos-Pons will be revealed to speak about issues such as “cultural hybridity”, creolization and the situation of the African contemporary art or also the representation of the Black body in art. A second part is centred on the notions of exile, Diaspora, discomfort caused by nomadism and the “in-between” status. The practices of Mona Hatoum, Arab women artists such as Lalla Essaydi, Shadi Ghadirian or Ghazel, and the works of Kimsooja, Janine Antoni and Ana de la Cueva will allow us to enter the heart of an artistic scene the critical stakes of which carry us to think about the globalisation, within its positive (enrichment, exchanges, dialog) as negatives aspects (standardisation, losing of local specificities). Each of these artists dreads the world and the society in a poetic and political way. The third part is finally dedicated to the women artists who chose the use of traditional techniques as embroidery, weaving or tapestry. Since the explosion of the feminist scene during the 1970s until current works, embroidery is henceforth no more considered as a typically feminine leisure, but as a real political weapon. A weapon steered towards the male chauvinism, patriarchy or gendered disparities. In this frame, the practices of such artists as Elaine Reichek, Judy Chicago, Louise Bourgeois, Joana Vasconcelos, Tracey Emin, Ghada Amer, Cathy Burghi, will allow to approach the embroidery in contemporary art in a diversified and heterogeneous way. Through these various analyses, we observe the deconstruction of art hierarchy and that contemporary textile art appears as a committed and relevant art, proposing perspectives of rich reflections in connection with the actual issues of our world.

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