• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • Tagged with
  • 5
  • 5
  • 4
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 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

Determinação dos limiares de normalidade dos parâmetros acústicos da voz / Determination of the thresholds of normality of the acoustic parameters of the voice

Andrade, Luciana Mara de Oliveira 25 July 2003 (has links)
Existe uma gama de pesquisas destinada à análise digital da voz, cujo intento é o de propiciar ferramentas que possam auxiliar no processo diagnóstico e terapêutico. O intercâmbio entre engenharia e áreas da saúde, como medicina e fonoaudiologia, tem apresentado expansiva importância para um melhor entendimento e aprimoramento de um “saber" mais comum, onde a aplicabilidade de dados quantitativos associados a dados qualitativos acresce conhecimentos nestas duas vertentes. O intuito deste trabalho é o de utilizar dados quantitativos através de uma ferramenta de análise acústica da voz e avaliar sua acuracidade. Para tanto, fez-se exames clínicos e avaliações perceptivas em 130 voluntários. Os resultados obtidos conjuminam com a proposição deste estudo, sendo expressivamente promissores com a exatidão da inter-relação dos achados, com o qual pode-se concluir a veracidade da ferramenta utilizada / The diagnosis and therapeutic process of the voice has incorporated digital voice analysis as a useful tool for the specialists. The interchange between engineering and health sciences has improved the understanding of this interface area and the association between quantitative data and qualitative evaluation enhanced both. The purpose of this work is to use the acoustical analysis of voice in order to evaluate how accurate is that tool compared with clinical and perceptual diagnostics. A set of 130 subjects was used to evaluate this comparison. The results are consistent and match favorably the clinic and perceptual achievements
2

Determinação dos limiares de normalidade dos parâmetros acústicos da voz / Determination of the thresholds of normality of the acoustic parameters of the voice

Luciana Mara de Oliveira Andrade 25 July 2003 (has links)
Existe uma gama de pesquisas destinada à análise digital da voz, cujo intento é o de propiciar ferramentas que possam auxiliar no processo diagnóstico e terapêutico. O intercâmbio entre engenharia e áreas da saúde, como medicina e fonoaudiologia, tem apresentado expansiva importância para um melhor entendimento e aprimoramento de um “saber” mais comum, onde a aplicabilidade de dados quantitativos associados a dados qualitativos acresce conhecimentos nestas duas vertentes. O intuito deste trabalho é o de utilizar dados quantitativos através de uma ferramenta de análise acústica da voz e avaliar sua acuracidade. Para tanto, fez-se exames clínicos e avaliações perceptivas em 130 voluntários. Os resultados obtidos conjuminam com a proposição deste estudo, sendo expressivamente promissores com a exatidão da inter-relação dos achados, com o qual pode-se concluir a veracidade da ferramenta utilizada / The diagnosis and therapeutic process of the voice has incorporated digital voice analysis as a useful tool for the specialists. The interchange between engineering and health sciences has improved the understanding of this interface area and the association between quantitative data and qualitative evaluation enhanced both. The purpose of this work is to use the acoustical analysis of voice in order to evaluate how accurate is that tool compared with clinical and perceptual diagnostics. A set of 130 subjects was used to evaluate this comparison. The results are consistent and match favorably the clinic and perceptual achievements
3

Análise acústica da voz de obesos mórbidos pré e pós tratamento cirúrgico para a obesidade / Acoustic analysis of the voice of obese morbid before and later surgical treatment for the obesity

Dell\'Acqua, Raquel Malara 02 May 2007 (has links)
Devido ao grande aumento da obesidade no Brasil e no mundo e aos riscos que esta afecção oferece à saúde dos indivíduos, existem diversos tipos de tratamento possíveis para reverter esse quadro. Entre eles, o tratamento cirúrgico, que é o mais indicado para os casos classificados como obesidade mórbida. Por meio desse tratamento é comumente possível a redução de até 40% do peso inicial do indivíduo. Contudo, existem casos em que a perda ultrapassa esse percentual. Com essa perda de gordura tão significativa, o organismo todo apresenta modificações nitidamente observáveis, e tais alterações incluem o trato vocal. Sabendo que a voz é um sinal complexo composto pelo sinal vocal produzido na glote e pelas ressonâncias do trato vocal, observou-se a necessidade de avaliar se os parâmetros vocais sofrem alteração com a drástica mudança de peso corpóreo. Este estudo comparou as análises acústicas e perceptivo-auditivas antes e depois do tratamento cirúrgico para a obesidade, tendo como objetivo verificar se alterações vocais acontecem após o emagrecimento. Os resultados apontam que nas perdas de peso de até 40%, os parâmetros perceptivo auditivos e os acústicos não apresentaram alterações estatisticamente relevantes, e para perdas maiores que 50% observou-se a alteração significativa em dois parâmetros específicos, o PA e o Ex, o que significa: melhora na movimentação das pregas vocais com aumento de ruído na voz após o emagrecimento. Contudo, a amostra que compõe esse percentual de perda de peso é composta por apenas um participante, portanto tais resultados não podem ser generalizados. / Due to the significant increase of obesity in Brazil and in the world and the risks involving the health of individuals, several types of treatment have been recommended in an attempt to change this scenario. The surgical treatment is believed to be the most suitable for the majority of morbid obesity cases. This type of procedure usually reduces up to 40% of the individual initial weight and in some cases this ratio can be even higher. However, a significant weight loss usually results in several significant bodily changes including the vocal tract. As the voice signal is very complex and comprises a glottal pulse equalized by vocal tract resonance, it seems reasonable to evaluate how voice parameters change with weight reduction. The purpose of this study is to compare perceptive-auditive and acoustics analysis of the voice, before and after the surgical approach to obesity to check if the vocal changes occur after the weight reduction. The results indicate that in weight losses up to 40% the perceptive-auditive and acoustics parameters did not represent statistically relevant alterations, but in weight losses higher than 50%, significant changes were observed in two specific parameters, PA and Ex, including improvement of vocal folds movement and increase of loudness of voice after weight loss. However, the sample of weight loss was insufficient because it was limited to one participant; therefore it should not be generalized.
4

Análise acústica da voz de obesos mórbidos pré e pós tratamento cirúrgico para a obesidade / Acoustic analysis of the voice of obese morbid before and later surgical treatment for the obesity

Raquel Malara Dell\'Acqua 02 May 2007 (has links)
Devido ao grande aumento da obesidade no Brasil e no mundo e aos riscos que esta afecção oferece à saúde dos indivíduos, existem diversos tipos de tratamento possíveis para reverter esse quadro. Entre eles, o tratamento cirúrgico, que é o mais indicado para os casos classificados como obesidade mórbida. Por meio desse tratamento é comumente possível a redução de até 40% do peso inicial do indivíduo. Contudo, existem casos em que a perda ultrapassa esse percentual. Com essa perda de gordura tão significativa, o organismo todo apresenta modificações nitidamente observáveis, e tais alterações incluem o trato vocal. Sabendo que a voz é um sinal complexo composto pelo sinal vocal produzido na glote e pelas ressonâncias do trato vocal, observou-se a necessidade de avaliar se os parâmetros vocais sofrem alteração com a drástica mudança de peso corpóreo. Este estudo comparou as análises acústicas e perceptivo-auditivas antes e depois do tratamento cirúrgico para a obesidade, tendo como objetivo verificar se alterações vocais acontecem após o emagrecimento. Os resultados apontam que nas perdas de peso de até 40%, os parâmetros perceptivo auditivos e os acústicos não apresentaram alterações estatisticamente relevantes, e para perdas maiores que 50% observou-se a alteração significativa em dois parâmetros específicos, o PA e o Ex, o que significa: melhora na movimentação das pregas vocais com aumento de ruído na voz após o emagrecimento. Contudo, a amostra que compõe esse percentual de perda de peso é composta por apenas um participante, portanto tais resultados não podem ser generalizados. / Due to the significant increase of obesity in Brazil and in the world and the risks involving the health of individuals, several types of treatment have been recommended in an attempt to change this scenario. The surgical treatment is believed to be the most suitable for the majority of morbid obesity cases. This type of procedure usually reduces up to 40% of the individual initial weight and in some cases this ratio can be even higher. However, a significant weight loss usually results in several significant bodily changes including the vocal tract. As the voice signal is very complex and comprises a glottal pulse equalized by vocal tract resonance, it seems reasonable to evaluate how voice parameters change with weight reduction. The purpose of this study is to compare perceptive-auditive and acoustics analysis of the voice, before and after the surgical approach to obesity to check if the vocal changes occur after the weight reduction. The results indicate that in weight losses up to 40% the perceptive-auditive and acoustics parameters did not represent statistically relevant alterations, but in weight losses higher than 50%, significant changes were observed in two specific parameters, PA and Ex, including improvement of vocal folds movement and increase of loudness of voice after weight loss. However, the sample of weight loss was insufficient because it was limited to one participant; therefore it should not be generalized.
5

Ecological and acoustic investigations of jellyfish (Scyphozoa and Hydrozoa)

Lynam, Christopher Philip January 2006 (has links)
As the biomass of jellyfish (medusae of the Scyphozoa and Hydrozoa) has risen in numerous locations worldwide, awareness of their potential to exert a controlling influence on marine ecosystems and hinder the recruitment of fish stocks has increased. Medusae are capable of intensive, size–selective, predation on zooplankton, which may alter the composition of the plankton community. Jellyfish are often found in dense layers, up to hundreds of metres thick, which can extend horizontally for hundreds of kilometres. Such aggregations may benefit specialist feeders, such as turtles, that rely upon jellyfish for food and those fish that are able to find refuge under the jellyfish umbrellas. Nonetheless, the predominance of jellyfish in pelagic ecosystems is not generally viewed as desirable; in fact, this situation has been portrayed as the result of pollution and overexploitation of otherwise productive seas. However, jellyfish are sensitive indicators of environmental change, and their populations appear to respond to climatic fluctuations, so jellyfish warrant study for their intrinsic ecosystem role particularly given present concerns over climate change. With growing acceptance that fishery management should take an holistic ‘ecosystem approach’, knowledge of the interactions between jellyfish, fisheries and climate may be vital in progression towards the goal of ecosystem–based sustainable management of fisheries. Unfortunately, due to their gelatinous nature, medusae are difficult to sample using conventional netting techniques and data on changes in distribution and abundance are consequently sparse. Recent studies have demonstrated that medusae can be detected acoustically and that this technique could provide a rapid and cost–effective estimate of their biomass and distribution. This thesis reports my endeavour to demonstrate the ecosystem role of medusae and to develop acoustic techniques to monitor their biomass. Through regession analyses, I link the abundance of medusae (Aurelia aurita, Cyanea lamarckii, and Cyanea capillata) in regions of the North Sea to climatic fluctuations, as quantified by the North Atlantic Oscillation Index, and show that medusae may be important indicators of regional ecosystem change. The mechanisms linking climatic fluctuations to ecosystem changes are explored via a correlative modelling approach using General Additive Models; I show that the mechanisms are location dependent and explainable in terms of direct, rapidly responding (intra–annual) influences (surface warming, river run–off, and wind–driven mixing and advection) and longer–term (interannual) oceanographic responses (changes in circulation currents i.e. the northward extent of the gulf stream and relative strength of inflow into the North Sea of the North Atlantic current, Continental Shelf Jet and Arctic waters). I present correlative evidence for a detrimental impact by Aurelia aurita on herring 0–group recruitment, once the influence of interannual change in herring spewing stock biomass on recruitment is factored out through modelling with a Ricker stock–recruitment relationship. Similarly, a commensal relationship between whiting and Cyanea spp. medusae is shown to improve North Sea whiting survival to the 1–group. In progress towards the automated acoustic identification of species, I have developed an in situ discrimination tool that can distinguish between echoes from: Aequorea aequorea; Chrysaora hysoscella; clupeid fish (sardine, anchovy and round herring); and horse mackerel/Cape hake. The technique relies upon characteristic differences in echo strength between frequencies, which are determined for each jellyfish species and finfish group using combined multifrequency acoustic and pelagic trawl samples. This method has facilitated the world’s first acoustic–based estimate of jellyfish biomass in the Namibian Benguela Sea. The 12.2 million tonnes of biomass of medusae (Aequorea aequorea and Chrysaora hysoscella) in the Namibian Benguela Sea was found to be greater than the combined biomass, 3.6 million tonnes, of commercially important fish (horse mackerel, Cape hake, sardines, anchovy, and round herring) in the same area. These results suggest that medusae may have an important role in the Benguela ecosystem that has previously been overlooked and that their biomass should be monitored.

Page generated in 0.0822 seconds