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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.
41

The Efficacy of Laryngeal Imaging to Assess the Effect of Vocal Fold Masses on Vibratory Function

Powell, Maria E. 05 June 2015 (has links)
No description available.
42

Analyses and application of piezoelectric actuator in decoupled vibratory feeding

Hu, Zhaoli 22 November 2005 (has links)
No description available.
43

Sensing the environment : development of monitoring aids for persons with profound deafness or deafblindness

Ranjbar, Parivash January 2009 (has links)
Earlier studies of persons with deafness (D) and/or deafblindness (DB) have primarily focused on the mobility and communication problems. The purpose of the present study was to develop technology for monitoring aids to improve the ability of persons with D and/or DB to detect, identify, and perceive direction of events that produce sounds in their surroundings. The purpose was achieved stepwise in four studies. In Study I, the focus was on hearing aids for persons with residual low frequency hearing. In Study II-IV, the focus was on vibratory aids for persons with total D. In Study I, six signal processing algorithms (calculation methods) based on two principles, transposition and modulation, were developed and evaluated regarding auditory identification of environmental sounds. Twenty persons with normal hearing listened to 45 environmental sounds processed with the six different algorithms and identified them in three experiments. In Exp. 1, the sounds were unknown and the subjects had to identify them freely. In Exp. 2 and 3, the sounds were known and the subjects had to identify them by choosing one of 45 sounds. The transposing algorithms showed better results (median value in Exp. 3, 64%-69%) than the modulating algorithms (40%-52%) did, and they were good candidates for implementing in a hearing aid for persons with residual low frequency hearing. In Study II, eight algorithms were developed based on three principles, transposition, modulation, and filtration – in addition to No Processing as reference, and evaluated for vibratory identification of environmental sounds. The transposing algorithms and the modulating algorithms were also adapted to the vibratory thresholds of the skin. Nineteen persons with profound D tested the algorithms using a stationary, wideband vibrator and identified them by choosing one of 10 randomly selected from the list of 45 sounds. One transposing algorithm and two modulating algorithms showed better (p<0.05) scores than did the No Processing method. Two transposing and three modulating algorithms showed better (p<0.05) scores than did the filtering algorithm. Adaptation to the vibratory thresholds of the skin did not improve the vibratory identification results. In Study III, the two transposing algorithms and the three modulating algorithms with the best identification scores in Study II, plus their adapted alternative, were evaluated in a laboratory study. Five persons from Study II with profound D tested the algorithms using a portable narrowband vibrator and identified the sounds by choosing one of 45 sounds in three experiments (Exp. 1, 2, and 3). In Exp. 1, the sounds were pre-processed and directly fed to the vibrator. In Exp. 2 and 3, the sounds were presented in an acoustic test room, without or with background noise (SNR=+5 dB), and processed in real time. Five of the algorithms had acceptable results (27%-41%) in the three experiments and constitute candidates for a miniaturized vibratory aid (VA). The algorithms had the same rank order in both tests in the acoustic room (Exp. 2, and 3), and the noise did not worsen the identification results. In Study IV, the portable vibrotactile monitoring aid (with stationary processor) for detection, identification and directional perception of environmental sounds was evaluated in a field study. The same five persons with profound D as in Study III tested the aid using a randomly chosen algorithm, drawn from the five with the best results in Study III, in a home and in a traffic environment. The persons identified 12 events at home and five events in a traffic environment when they were inexperienced (the events were unknown) and later when they were experienced (the events were known). The VA consistently improved the ability with regard to detection, identification and directional perception of environmental sounds for all five persons. It is concluded that the selected algorithms improve the ability to detect, and identify sound emitting events. In future, the algorithms will be implemented in a low frequency hearing aid for persons with low frequency residual hearing or in a fully portable vibratory monitoring aid, for persons with profound D or DB to improve their ability to sense the environment.
44

Modelling of MEMS vibratory gyroscopes utilizing phase detection

Dreyer, Antonie Christoffel 03 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2008. / This thesis aims to contribute to the modelling and analysis of MEMS gyroscope technologies. Various gyroscope types are studied, and the phase-based vibratory gyroscope is then selected for further investigation. In the literature, vibratory MEMS gyroscopes are mostly used in a single excitation and amplitude detection mode. However, a dual excitation and phase detection mode has recently been proposed, since phase-based detection, as opposed to amplitude-based detection modes, may be expected to increase measurement accuracy (in turn since improved signal-to-noise ratios may be expected). However, the presented analytical model was relatively crude, and the assumptions made appear unrealistic. Accordingly, in this thesis, an improved analyticalmodel is developed. To describe the dual excitation and phase detection problem more comprehensively, principles of classical dynamics are used herein to investigate the dual excitation of a two degree of freedom spring-mass-damper system subjected to an applied rotation rate. In doing so, an analytical formulation including mechanical coupling effects is extended into a generalized form, after which the amplitude and phase responses of the mechanically uncoupled system are interpreted. The differences between the amplitude and phase measurement techniques are illustrated. Finally, the system is modelled numerically, and the scale factor of a hypothetical device based on the phase-based detection method is optimized, subject to constraints on the nonlinearity of the device, using constrained mathematical optimization techniques.
45

Estudo do efeito da vibração no tratamento da disfunção temporomandibular através de um protótipo de placa vibratória oclusal / Study of the effectiveness of vibratory plate in the treatment of dysfunction temporomandibular

Luca, Carlos Eduardo Pitta de 13 December 2010 (has links)
Este estudo teve como objetivo estudar uma placa oclusalcom estimulação vibratória (POV) de base, para o tratamento da dor crônica miofascial. Foram selecionados 18 pacientes com mialgia crônica facial, de acordo com os Critérios para Diagnóstico em Pesquisa RDC . Os pacientes tinham entre 18 e 65 anos de idade, pertenciam ao sexo feminino e haviam usado placa estebilizadora acrílica por mais de 6 meses, e permaneciam com dor muscular. Foram excluídos pacientes com Disfunção Temporomandibular, que haviam feito uso de analgésicos ou de moduladores de sono, e pacientes desdentados parciais ou totais. A variável analisada foi a dor reportada pelos pacientes, usando a Escala Visual Analógica (EVA) de 100mm, medindo-se antes da instalação da POV, e um mes após o seu uso. Das 18 POV instaladas, 10 apresentaram falhas no mecanismo vibratório. As médias da EVA para os 8 pacientes que utilizaram a POV durante 1 mês foram de 56,62±22.82mm na aferição inicial e média de EVA final de 24,75±20,52mm, com p=0,011. Dos 8 pacientes apenas 4 concordaram com o uso da placa oclusal inativa (POI) por 30 dias, separadas por um período de wash-out de pelo menos 8 meses. Os níveis de dor da escala VAS foram a única variável analisada, e foram registrados antes e após o uso das placas. Foram utilizadas os testes t-teste pareado e ANOVA para medidas repetidas, para se obter os resultados estatísticos. No início do estudo, os níveis médios da VAS de dor antes de se utilizar a placa vibratória de maneira ativa e inativa foram 54,5±19,8 milímetros, e 44,0±13,6 milímetros, respectivamente. A comparação entre esses valores de referência não apresentaram diferença estatística (p> 0,05, teste t pareado). A variação média nos níveis de dor (VAS póspré) ao usar o mesmo tipo de placa, de maneira ativa e inativa foi de -42,0±-30,3 milímetros e 29,5±21,5 milímetros, e o t-teste revelou uma diferença significativa entre os dois grupos (p = 0,07). Foi feitauma nova análise, utilizando-se as mesmas medidas, através da Análise de Variância ANOVA, onde encontrou-se diferença estatisticamente significante (f(3,9)=7.543, p=0.008) antes do uso das placas ativas e das inativas. Entretanto, após o uso da correção com o teste de Bonferroni, foram encontrados resultados condizentes com aqueles obtidos na análise feita pelo programa do teste t. (p>0.05). Pode-se concluir que do uso da vibração como mecanismo de controle da DTM foi eficaz, mas a POV falhou na maioria dos casos devido a problemas mecânicos. / This study aimed to study an occlusal splint with vibratory stimulation (VibsS) as standard, for the treatment of chronic myofascial pain. Were selected 18 patients with chronic facial myalgia, according to the Research Diagnostic Criteria for Temporomandibular Disorders, RDC-TMD.The patients were between 18 and 65years old, female, using stabilization splints for more than six months, and that remained with muscle pain. Were excluded patients with Temporomandibular Disorders, which had made use of analgesics or sleeps modulators and those who were partially or totally edentulous. The analyzed variable was pain reported by patients using visual analog scale (VAS) of 100mm, measuring before the installation of VibsS, and one month after its use. Were installed 18 VibsS; 10 failures in the vibrating mechanism.The mean VAS for the 8 patients who used the VibsS for 1 month were 56.62 ± 22.82mm to measure initial and final mean VAS of 24.75 ± 20.52 mm, p = 0.011. From these 8 patients, only four agreed to the use of an occlusal splints inactive for 30 days, separated by a wash-out period of at least 8 months. The levels of pain-VAS score was the only variable analyzed, and were recorded before and after use of the splints. Were used paired t-tests and ANOVA for repeated measures to obtain the statistics. At baseline, mean levels of VAS pain before using the vibrating splint active and inactive were 54.5±19.8 mm, and 44.0±13.6 mm, respectively. The comparison of these reference values showed no statistical difference (p> 0.05, paired t-test). The average change in pain levels (VAS post-pre) when using the same type of analysis, with active and inactive splints was -42.0±- 30.3 and 29.5 mm±21.5 mm, and the t-test showed a significant difference between the two groups (p = 0.07). After that, was made, a new analysis, using the same measures through the analysis of variance ANOVA, where were found a statistically significant difference (f (3,9) = 7543, p = 0.008) before the use of active boards and inactive. However, after using the correction with the Bonferroni test, we found results consistent with those obtained in the analysis performed by the test program t. (p>0.05). Conclusion: This study showed that is an effective use of vibration as a control mechanism of TMD, but this VibsS failed in most cases due to mechanical problems.
46

Vibro-driveability -a field study of vibratory driven sheet piles in non-cohesive soils

Viking, Kenneth January 2002 (has links)
No description available.
47

Vibro-driveability -a field study of vibratory driven sheet piles in non-cohesive soils

Viking, Kenneth January 2002 (has links)
No description available.
48

Schwingungstechnische Auslegung von Betonrohrfertigern

Schwabe, Jörg-Henry 06 May 2002 (has links) (PDF)
Die Arbeit ist der Weiterentwicklung der Formgebungs- und Verdichtungsausrüstungen zur Herstellung von Beton- und Stahlbetonrohren gewidmet. Es werden die Grundlagen für eine schwingungstechnische Auslegung von Betonrohrfertigern mit stehendem und steigendem Kern geschaffen. Den Ausgangspunkt bildet die Untersuchung des Verdichtungsprozesses in Rohrfertigern und der Einflußgrößen auf die Vibrationsverdichtung des Betongemenges. Es werden experimentelle Untersuchungen an einem Versuchsstand und praktische industrielle Erfahrungen dargestellt. Für die schwingungstechnische Auslegung der Verdichtungseinrichtung von Rohrfertigern werden diskrete Modelle mit analytischen Lösungen sowie Modelle zur numerischen Simulation auf der Basis der Mehrkörperdynamik und der Finite-Elemente-Methode gebildet. Es erfolgen Empfehlungen zur Auslegung und Ansätze zur Weiterentwicklung von Rohrfertiger.
49

Efeito da vibração gerada em plataforma oscilante/vibratória em indivíduos com síndrome metabólica ou paralisia cerebral / Effect of vibration generated in oscillating/vibratory platform in individuals with metabolic syndrome or cerebral palsy

Danúbia da Cunha de Sá Caputo 30 March 2015 (has links)
A realização de atividade física regular é uma intervenção não farmacológica com grandes benefícios para melhora da qualidade de vida, redução da morbidade e da mortalidade de disfunções cardiorrespiratórias, controle da síndrome metabólica (SM), bem como no manejo de portadores de distúrbios neurológicos como na paralisia cerebral (PC). Os exercícios de vibração de corpo inteiro (EVCI) são produzidos quando o indivíduo está em contato com a base de uma plataforma oscilante/vibratória (POV) ligada devido a efeitos de vibrações sinusoidais e deterministas produzidas por essas plataformas. Os EVCI têm sido utilizados por pessoas treinadas e não treinadas e no tratamento de pacientes com diferentes desordens clínicas. Efeitos biológicos como aumento da flexibilidade e da força muscular são relatados através da realização destes exercícios. O objetivo deste estudo foi investigar os efeitos das vibrações geradas em POV em pacientes com SM ou com PC. Em relação aos estudos com SM, foi realizada uma busca no banco de dados PubMed para a palavra-chave flexibilidade e sua relação com os EVCI, bem como um estudo de caso sobre o efeito dos EVCI na flexibilidade de paciente com SM. Em relação à investigação com PC, revisão sistemática foi realizada sobre os efeitos dos EVCI em portadores de PC através de pesquisas nas bases de dados PubMed, Cochrane Library, Cinahl (Ebsco Host), PEDro, Science Direct and Scopus. Os resultados obtidos através do uso de protocolo de EVCI com baixa frequência (5 a 14 Hz) foi verificado aumento da flexibilidade anterior de tronco em paciente com SM e parece haver uma estabilização desta medida ao longo do protocolo proposto de onze sessões. Um importante número de publicações é encontrado no PubMed para a palavra-chave flexibilidade e os achados de nossa investigação revelam que há interesse em avaliar o efeito dos EVCI na flexibilidade dos indivíduos. Os efeitos pesquisados em pacientes com PC incluem fortalecimento muscular, redução da espasticidade, aumento na flexibilidade, aumento de densidade mineral óssea e melhora do controle postural. Em conclusão, a análise dos estudos apresentados permite sugerir que os EVCI podem ser uma modalidade de intervenção segura para portadores de SM, melhorando a flexibilidade anterior de tronco. Além disso, a revisão realizada mostra melhora da flexibilidade em vários grupos estudados. Para portadores de PC, foi verificado que os EVCI melhoram vários parâmetros clínicos de portadores, porém, como os protocolos não são descritos com detalhes, as evidências para uma definição de melhores parâmetros para esta população permanecem inconclusiva. / The regular physical activity is a non-pharmacological intervention with great benefits for improving quality of life, reduce morbidity and mortality of cardiopulmonary dysfunction and to control of metabolic syndrome (MS), and in the management of patients with neurological disorders such as in cerebral palsy (CP). The whole body vibration exercises (WBVE) are produced when the subject is in contact with the base of an oscillating/vibratory platform (OVP) due to sinusoidal and deterministic vibrations generated by these platforms. The WBVE have been used by people trained and untrained and in the treatment of patients with different clinical disorders. Biological effects such as increased flexibility and muscle strength are related to these WBVE. The aim of this study was to investigate the effects of vibrations generated in OVP in patients with MS or PC. In studies with MS, a search in PubMed database for the keyword "flexibility" and its relation to the WBVE was carried out, and a case study on the effect of the patient WBVE flexibility with MS. Regarding to the search involving PC, a systematic review was performed about the effect of WBVE in CP patients through the databases PubMed, Cochrane Library, CINAHL (Ebsco Host), PEDro, Science Direct and Scopus. The results obtained from the WBVE protocol using low frequency (5 to 14 Hz) have shown to increase the anterior trunk flexibility in patients with MS, that is stabilized over the eleventh session. An important number of publications is found in PubMed for the keyword "flexibility" and the findings of our research show that there is interest in evaluating the effect of WBVE in the flexibility of subjects. The effects reported in patients with CP include muscle strengthening, reducing spasticity, increased flexibility, increased bone mineral density and improves postural control. In conclusion, the analysis of different studies suggest that WBVE can be an intervention modality for patients with MS, improving anterior trunk flexibility. Furthermore, the review carried shows improved flexibility in several groups searched in the revision. For CP patients, it was found that WBVE improve various clinical parameters of patients, however, as the protocols are not described in detail, the evidence for a definition of best parameters for this population remain inconclusive.
50

Efeito da vibração gerada em plataforma oscilante/vibratória em indivíduos com síndrome metabólica ou paralisia cerebral / Effect of vibration generated in oscillating/vibratory platform in individuals with metabolic syndrome or cerebral palsy

Danúbia da Cunha de Sá Caputo 30 March 2015 (has links)
A realização de atividade física regular é uma intervenção não farmacológica com grandes benefícios para melhora da qualidade de vida, redução da morbidade e da mortalidade de disfunções cardiorrespiratórias, controle da síndrome metabólica (SM), bem como no manejo de portadores de distúrbios neurológicos como na paralisia cerebral (PC). Os exercícios de vibração de corpo inteiro (EVCI) são produzidos quando o indivíduo está em contato com a base de uma plataforma oscilante/vibratória (POV) ligada devido a efeitos de vibrações sinusoidais e deterministas produzidas por essas plataformas. Os EVCI têm sido utilizados por pessoas treinadas e não treinadas e no tratamento de pacientes com diferentes desordens clínicas. Efeitos biológicos como aumento da flexibilidade e da força muscular são relatados através da realização destes exercícios. O objetivo deste estudo foi investigar os efeitos das vibrações geradas em POV em pacientes com SM ou com PC. Em relação aos estudos com SM, foi realizada uma busca no banco de dados PubMed para a palavra-chave flexibilidade e sua relação com os EVCI, bem como um estudo de caso sobre o efeito dos EVCI na flexibilidade de paciente com SM. Em relação à investigação com PC, revisão sistemática foi realizada sobre os efeitos dos EVCI em portadores de PC através de pesquisas nas bases de dados PubMed, Cochrane Library, Cinahl (Ebsco Host), PEDro, Science Direct and Scopus. Os resultados obtidos através do uso de protocolo de EVCI com baixa frequência (5 a 14 Hz) foi verificado aumento da flexibilidade anterior de tronco em paciente com SM e parece haver uma estabilização desta medida ao longo do protocolo proposto de onze sessões. Um importante número de publicações é encontrado no PubMed para a palavra-chave flexibilidade e os achados de nossa investigação revelam que há interesse em avaliar o efeito dos EVCI na flexibilidade dos indivíduos. Os efeitos pesquisados em pacientes com PC incluem fortalecimento muscular, redução da espasticidade, aumento na flexibilidade, aumento de densidade mineral óssea e melhora do controle postural. Em conclusão, a análise dos estudos apresentados permite sugerir que os EVCI podem ser uma modalidade de intervenção segura para portadores de SM, melhorando a flexibilidade anterior de tronco. Além disso, a revisão realizada mostra melhora da flexibilidade em vários grupos estudados. Para portadores de PC, foi verificado que os EVCI melhoram vários parâmetros clínicos de portadores, porém, como os protocolos não são descritos com detalhes, as evidências para uma definição de melhores parâmetros para esta população permanecem inconclusiva. / The regular physical activity is a non-pharmacological intervention with great benefits for improving quality of life, reduce morbidity and mortality of cardiopulmonary dysfunction and to control of metabolic syndrome (MS), and in the management of patients with neurological disorders such as in cerebral palsy (CP). The whole body vibration exercises (WBVE) are produced when the subject is in contact with the base of an oscillating/vibratory platform (OVP) due to sinusoidal and deterministic vibrations generated by these platforms. The WBVE have been used by people trained and untrained and in the treatment of patients with different clinical disorders. Biological effects such as increased flexibility and muscle strength are related to these WBVE. The aim of this study was to investigate the effects of vibrations generated in OVP in patients with MS or PC. In studies with MS, a search in PubMed database for the keyword "flexibility" and its relation to the WBVE was carried out, and a case study on the effect of the patient WBVE flexibility with MS. Regarding to the search involving PC, a systematic review was performed about the effect of WBVE in CP patients through the databases PubMed, Cochrane Library, CINAHL (Ebsco Host), PEDro, Science Direct and Scopus. The results obtained from the WBVE protocol using low frequency (5 to 14 Hz) have shown to increase the anterior trunk flexibility in patients with MS, that is stabilized over the eleventh session. An important number of publications is found in PubMed for the keyword "flexibility" and the findings of our research show that there is interest in evaluating the effect of WBVE in the flexibility of subjects. The effects reported in patients with CP include muscle strengthening, reducing spasticity, increased flexibility, increased bone mineral density and improves postural control. In conclusion, the analysis of different studies suggest that WBVE can be an intervention modality for patients with MS, improving anterior trunk flexibility. Furthermore, the review carried shows improved flexibility in several groups searched in the revision. For CP patients, it was found that WBVE improve various clinical parameters of patients, however, as the protocols are not described in detail, the evidence for a definition of best parameters for this population remain inconclusive.

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