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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.
81

Some New Methods For Improved Fractal Image Compression

Ramkumar, M 08 1900 (has links) (PDF)
No description available.
82

HINT Brasil : estudo em portadores de perdas auditivas / HINT Brazil : a study in patients with hearing loss

Arieta, Aline de Moraes, 1981- 22 August 2018 (has links)
Orientadores: Everardo Andrade da Costa, Christiane Marques do Couto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T10:10:32Z (GMT). No. of bitstreams: 1 Arieta_AlinedeMoraes_D.pdf: 1729442 bytes, checksum: 2887ecc98db30769bd998782cb6716d0 (MD5) Previous issue date: 2013 / Resumo: A investigação do reconhecimento da fala na presença de ruído competidor, em situações de escuta assemelhadas às do dia a dia, torna-se cada vez mais necessária. Atualmente, na rotina audiológica nacional, esta avaliação ainda é realizada sem ruído, limitando as informações sobre o desempenho dos indivíduos em condições de vida real. Este problema se agrava nas perdas auditivas sensorioneurais, de alta ocorrência na sociedade. O objetivo desta pesquisa é avaliar o reconhecimento da fala sem e com ruído competidor, em diferentes grupos populacionais, com o teste - Hearing in Noise Test - HINT BRASIL - Um total de 268 sujeitos, 180 do gênero masculino e 78 do feminino, foram avaliados e divididos em: 66 normo-ouvintes; 70 normo-ouvintes com história de exposição a ruído ocupacional; 80 com perda auditiva sensorioneural, com história de exposição a ruído ocupacional e 52 usuários de próteses auditivas. O HINT Brasil foi aplicado com fones de ouvido e em campo livre nas condições: sem ruído (S); com ruído frontal (RF); ruído à direita (RD); ruído à esquerda (RE). Além disso, o programa fornece uma média ponderada das condições com ruído, a qual denomina Ruído Composto (RC). Os resultados foram computados em dB(A) na condição sem ruído e em dB Relação Sinal/Ruído nas condições com ruído. Nos testes com ruído, os valores obtidos em campo livre foram piores do que os obtidos com fones de ouvido. O grupo de normo-ouvintes exposto a ruído ocupacional apresentou pior desempenho ao HINT Brasil, na condição RC, em relação aos normo-ouvintes não expostos. O grupo de sujeitos com perda auditiva sensorioneural apresentou respostas piores em todas as condições de aplicação do HINT Brasil quando comparados aos normo-ouvintes com e sem exposição. No grupo de usuários de próteses auditivas, o desempenho para o HINT Brasil foi melhor com o uso das próteses em relação a não utilização delas / Abstract: The investigation to recognize speech in day-to-day conditions becomes increasingly necessary. Currently, on the national routine audiological, this evaluation is still performed without noise, limiting the information about the performance of individuals in real-life conditions. This problem is aggravated on sensorineural hearing loss, which has high prevalence in society. The purpose of this research is to evaluate speech recognition with and without noise in different population groups, using the HINT Brazil (Hearing in Noise Test - Portuguese version of Brazil). A total of 268 people, 180 males and 78 females were evaluated: 66 normal hearing, 70 normal hearing individuals with a history of occupational noise exposure, 80 with sensorineural hearing loss, with a history of occupational noise exposure and 52 users hearing aids. The HINT Brazil was applied, with headphones and soundfield on conditions: quiet (Q); Noise Front (NF) Noise Right (NR); Noise Left (NL). Additionally, the program provides an average of the noise conditions called Noise Composed (NC). The results were calculated on dB (A) with no noise conditions and dB Signal to Noise Ratio (S/R) in noisy conditions. On the tests with noise, the values obtained in soundfield were worse than the ones with headphones. The normal hearing group exposed to occupation noise presents worse performance with the HINT Brazil, in the condition RC, comparing to the ones not exposed. The sensoneural hearing loss group presented worse performance in all the conditions of the HINT Brazil comparing to the normal hearing with and without exposure. On the hearing aid users group, the HINT performance was better using the hearing aids / Doutorado / Epidemiologia / Doutora em Saúde Coletiva
83

Ruído em ambiente escolar: desenvolvimento e verificação da eficácia de um programa de promoção de saúde auditiva / Noise in school environment: development and verification of the efficacy of an auditory health promotion program

Renata Falótico Taborda 26 May 2017 (has links)
INTRODUÇÃO: O ruído é considerado, mundialmente, como um problema de saúde pública. No ambiente escolar, o ruído é um fator de grande preocupação, devido a seus impactos e prejuízos, tanto para os alunos como para os funcionários, incluindo os professores. Os danos do ruído para as crianças podem englobar efeitos auditivos, de saúde em geral e cognitivos, afetando negativamente o desenvolvimento da aprendizagem. Dificuldades de concentração e engajamento, além de prejuízos para o sono e memória também são relatados. Muitas pesquisas vêm demonstrando que o ruído em salas de aula encontra-se acima dos valores recomendados. Desta forma, estudos que busquem a promoção da saúde auditiva e a conscientização da comunidade escolar com relação ao ruído são fundamentais, uma vez que podem contribuir para a melhoria da qualidade de vida dos atores envolvidos, bem como para a constituição de um ambiente acústico mais propício para a saúde e aprendizagem. OBJETIVOS: O objetivo geral do presente estudo foi o desenvolvimento e a verificação da eficácia de um programa de promoção de saúde auditiva em uma escola particular. Os objetivos específicos foram a verificação dos níveis de pressão sonora existentes nas dependências da escola antes e após o programa de intervenção; as queixas e o grau de desconforto com relação ao ruído dos alunos e dos professores da escola, por meio da aplicação de questionários específicos, pré e pós-intervenção; e a elaboração de uma proposta coletiva de intervenção na escola, norteada pelo Modelo Ecológico de Promoção da Saúde. MÉTODO: Participaram deste estudo alunos e funcionários de uma escola particular em Santana de Parnaíba, São Paulo. Os procedimentos realizados incluíram medições dos níveis de pressão sonora pré e pós-intervenção das salas de aulas e demais espaços da escola, aplicação de questionários pré e pós-intervenção nos alunos e professores para verificação de sintomas auditivos, extra-auditivos e grau de incômodo com o ruído no ambiente escolar. Além disso, foram realizadas as intervenções propriamente ditas, que foram desenvolvidas em conjunto a equipe da escola e alunos. RESULTADOS: Ao comparar as medições pré e pós-intervenção, pode-se observar diminuição estatisticamente significante dos níveis de ruído em determinadas salas de aula e anfiteatro. Já para outros espaços coletivos, como biblioteca e cantina, os níveis de ruído permaneceram sem diferença significante. Os questionários pré e pós-intervenção mostraram uma maior consciência acerca do ruído e intervenções efetivas para diminuição deste nas salas de aula. As intervenções realizadas conseguiram abranger todos os níveis propostos pelo Modelo Ecológico de Promoção da Saúde, com exceção do nível de políticas públicas. As ações tiveram caráter educativo, pedagógico, comunitário e físico, bem como foram desenvolvidas e implementadas em conjunto com a equipe pedagógica da escola e com os alunos. A escola realizou tratamento acústico nos espaços definidos como prioritários. CONCLUSÃO: Pode-se verificar que o programa desenvolvido, juntamente com a escola, teve impactos positivos, tais como redução nos níveis de ruído, mudanças no ambiente (tratamento acústico), bem como na cultura escolar, em relação à diminuição do ruído / INTRODUCTION: Noise is described worldwide as a public health problem. In the school environment, noise is a major concern due to the impacts and impairment it may cause in students and staff, including teachers. In the range of damage that noise may cause in children, we may enlist auditory problems, general health and also cognitive effects, which may affect their learning development. In some cases, difficulties with memory, concentration and also sleep are reported. Several studies have shown that noise in classroom is, commonly, above the recommended values. Thus, researches that aim to promote hearing health and awareness of the school community regarding noise are fundamental, since they can contribute to the improvement of life quality for education professionals, as well as for providing better acoustic environment for health and learning. PURPOSE: The overall aim of the present study was to develop and verify the efficacy of a hearing health promotion program in a private school. The specific objectives were to verify the sound pressure levels in the school before and after the intervention program; the complaints and the degree of discomfort regarding the noise of students and teachers from the school, through specific questionnaires, applied before and after intervention; and the elaboration of a collective intervention proposal in the school, guided by the Ecological Model of Health Promotion. METHODS: Participated in this study, students and employees from a private school of Santana de Parnaíba, São Paulo. The procedures performed included measurements of sound pressure pre and post intervention in the classrooms and in several environment of the school; we applied pre and post intervention questionnaires in students and teachers to verify auditory and extra-auditory symptoms and the degree of annoyance concerning noise in the school environment. Besides, we conducted intervention acts which were defined jointly with the school staff and students. RESULTS: Comparing pre and post-intervention measurements, a statistically significant reduction of noise levels was observed in some classrooms and in the amphitheater. On the other hand, for other collective places, such as library and canteen, noise levels remained without significant difference. The pre and post intervention questionnaires showed a greater awareness about noise and effective interventions to reduce it in classrooms. The interventions that we performed were effective to cover all levels proposed by the Ecological Model of Health Promotion, apart from the level of public policies. The actions were educational, pedagogical, community and physical, and they were developed and implemented in partnership with the pedagogical team and students. The school performed acoustic treatment in the spaces defined as priority. CONCLUSION: We verified that the developed program which was conducted along with the school, achieved positive impacts, such as noise levels reduction, changes in the environment (acoustic treatment), as well as in the habits of the school staff regarding noise reduction
84

Aplicação do método de Taguchi para redução de porosidade de peças fundidas sob pressão

Denilson José Viana 28 September 2012 (has links)
O processo de fundição sob pressão de alumínio tem se desenvolvido significativamente nas últimas décadas, ocupando um lugar de destaque na indústria por produzir componentes de engenharia inovadora. Dentre os problemas de qualidade deste processo, o mais recorrente é a porosidade causada por vários fatores, dentre eles os parâmetros do processo que são de difícil determinação, sendo comumente selecionados por meio da abordagem de tentativa e erro. A presente dissertação buscou responder a pergunta: Como determinar a melhor configuração de parâmetros do processo de fundição sob pressão de alumínio para minimizar a porosidade nas peças produzidas? Tendo como objetivo a melhoria da qualidade de uma peça de alumínio, fundida sob pressão, por meio da redução da porosidade. A principal contribuição desta dissertação concentra-se na aplicação do método de Taguchi utilizando dados categóricos ordinais (classes de porosidades) como característica de qualidade, por meio da análise da relação sinal-ruído ponderada. Os resultados dos experimentos foram analisados a partir do efeito médio dos fatores e da análise de variância (ANOVA). Como conclusão os parâmetros de temperatura do metal e velocidade de primeira e segunda fase de injeção foram os mais significativos na redução da porosidade da peça estudada. E ainda, o método de Taguchi alcançou o resultado esperado, trazendo significativa redução de porosidade na peça estudada por meio da otimização dos parâmetros do processo. / The aluminum die casting process has developed significantly in recent decades, occupying a prominent place for producing innovative engineering components. Among quality problems of this process is porosity due to several factors, including the process parameters that are difficult to determine, and are commonly selected by trial and error approach. This paper sought to answer the question: How to determine the best set of parameters of the aluminum die casting process to minimize porosity in the parts produced? Aiming improving die casting aluminum parts quality through reducing porosity. The main contribution of this paper focuses on the application of Taguchi method using ordinal categorical data (porosity classes) as a quality characteristic, by analyzing the weighted signal-to-noise ratio. The experimental results were analyzed from the average effect of factors and analysis of variance (ANOVA). In conclusion parameters metal temperature and speed of the first and second injection phase were the most significant in reducing the porosity of the part studied. Also, the Taguchi method achieved the expected result, bringing significant reduction of porosity in the part studied by optimizing the process parameters.
85

Detection of Human Emotion from Noise Speech

Nallamilli, Sai Chandra Sekhar Reddy, Kandi, Nihanth January 2020 (has links)
Detection of a human emotion from human speech is always a challenging task. Factors like intonation, pitch, and loudness of signal vary from different human voice. So, it's important to know the exact pitch, intonation and loudness of a speech for making it a challenging task for detection. Some voices exhibit high background noise which will affect the amplitude or pitch of the signal. So, knowing the detailed properties of a speech to detect emotion is mandatory. Detection of emotion in humans from speech signals is a recent research field. One of the scenarios where this field has been applied is in situations where the human integrity and security are at risk In this project we are proposing a set of features based on the decomposition signals from discrete wavelet transform to characterize different types of negative emotions such as anger, happy, sad, and desperation. The features are measured in three different conditions: (1) the original speech signals, (2) the signals that are contaminated with noise or are affected by the presence of a phone channel, and (3) the signals that are obtained after processing using an algorithm for Speech Enhancement Transform. According to the results, when the speech enhancement is applied, the detection of emotion in speech is increased and compared to results obtained when the speech signal is highly contaminated with noise. Our objective is to use Artificial neural network because the brain is the most efficient and best machine to recognize speech. The brain is built with some neural network. At the same time, Artificial neural networks are clearly advanced with respect to several features, such as their nonlinearity and high classification capability. If we use Artificial neural networks to evolve the machine or computer that it can detect the emotion. Here we are using feedforward neural network which is suitable for classification process and using sigmoid function as activation function. The detection of human emotion from speech is achieved by training the neural network with features extracted from the speech. To achieve this, we need proper features from the speech. So, we must remove background noise in the speech. We can remove background noise by using filters. wavelet transform is the filtering technique used to remove the background noise and enhance the required features in the speech.
86

Performance Evaluation of a Newly Developed MR-Compatible Mobile PET Scanner with Two Detector Layouts / 新規に開発したMR対応可搬型PET装置の2通りの検出器配置における性能評価

Watanabe, Masao 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22305号 / 医博第4546号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 増永 慎一郎, 教授 鈴木 実, 教授 溝脇 尚志 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
87

Techniky slučování kanálů za účelem zvýšení dynamického rozsahu kanálu s rozsahem ±10 V / Channel Merging Techniques for improving Dynamic Range of ± 10 V Signal Chain Channel

Dušek, Samuel January 2020 (has links)
Cílem této diplomové práce je změřit a vyhodnotit parametry techniky slučování kanálů, která je momentálně implementována v součástce AD7606C firmy Analog Devices. Poté, na základě výsledků z měření, navrhnout a odsimulovat několik možností, pomocí kterých by tato technika mohla dosahovat vyšších hodnot dynamického rozsahu a celkového harmonického zkreslení. V průběhů práce bylo zjištěno, že pomocí zvýšení zesílení kanálu s nižším rozsahem společně se snížením mezní frekvence celého signálového řetězce může tato technika dosahovat až 118.6 dB dynamického rozsahu, což je o 3.6 dB více, než bylo změřeno na AD7606C. Dále také bylo zjištěno, že pomocí jednoduchého algoritmu implementovaného v logickém bloku, je možné dosáhnout imunity vůči hodnotě externího rezistoru, který zákazníci používají jako součást anti-aliasingového filtru.
88

Hodnocení kvality signálů EKG / ECG quality evaluation

Vencel, Michal January 2021 (has links)
This seminar work deals with the topic of evaluating the quality of ECG signals. The introductory chapters explain the basic characteristics of ECG signals - measurement, the form of the measured signal, methods of analysis. The cardiac physiology and pathology is presented. The most common types of noise that occur in ECG signals are also mentioned. Further, the reader is acquainted with the importance of the issue of evaluating the quality of ECG signals. In the practical part of the work, two own methods for ECG quality evaluation are presented. First, a brief theoretical introduction to the techniques used in the creation of methoda is given, followed by a description of the principle of algorithms. In order to compare the functionality of the proposed methods, three more methods from other authors are presented. Their principle is briefly described. In the final chapter, all methods are subjected to functionality testing. The results are examined and all methods are compared with each other.
89

Identifikace pauz v rušeném řečovém signálu / Pause Identification in Degraded Speech Signal

Podloucká, Lenka January 2008 (has links)
This diploma thesis deals with pause identification with degraded speech signal. The speech characteristics and the conception of speech signal processing are described here. The work aim was to create the reliable recognizing method to establish speech and non-speech segments of speech signal with and without degraded speech signal. The five empty pause detectors were realized in computing environment MATLAB. There was the energetic detector in time domain, two-step detector in spectral domain, one-step integral detector, two-step integral detector and differential detector in cepstrum. The spectral detector makes use of energetic characteristics of speech signal in first step and statistic analysis in second step. Cepstral detectors make use of integral or differential algorithms. The detectors robustness was tested for different types of speech degradation and different values of Signal to Noise Ratio. The test of influence different speech degradation was conducted to compare non-speech detection for detectors by ROC (Receiver Operating Characteristic) Curves.
90

Kumulace biologických dat / Biological data averaging

Mlčoch, Marek January 2011 (has links)
The thesis deals with the biological data averaging applied to a periodical and repetitive signal, specifically to an ECG signals. There were used signals from MIT-BIH Arrhythmia database and ÚBMI database. Averaging was realized with constant, floating and exponential Windows, where was used the method of addition of the filtered residue. This method is intended to capture the slow variations from the input to the output signal. The outcomes of these methods can be used as a basis for further work, or function as an example of principled methods. Methods and its outcomes were created in Matlab.

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