京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第21915号 / 情博第698号 / 新制||情||120(附属図書館) / 京都大学大学院情報学研究科数理工学専攻 / (主査)教授 梅野 健, 教授 山下 信雄, 教授 守倉 正博 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

No description available.

No description available.

With the intention of improving process efficiency and product quality, Design of Experiments (DoE) is often applied in industry as a tool for engineers in planning experiments and product design. One of the methods in DoE is the Taguchi method that provides a practical procedure to design experiments with an appropriate number of tests for identifying optimal parametric settings of products. The purpose of this study is to investigate how Design of Experiments, specifically the Taguchi method, can be applied to analyze the performance of the lubricants used to stainless fasteners which are common products in various industries. The study has been implemented at the case company which manufactures stainless fasteners. Combining with qualitative and quantitative methods, this thesis work started from reviewing the previous research on DoE, the Taguchi method and various analysis tools as well as information on lubricants. Experiments were designed based on observations, interview, and literature collection. The actual tests were carried out on the case company's wax process where lubricants with different levels for the respective parameters were applied to screws and nuts. The fasteners were tested in a friction machine and UV lamp at the case company. The implemented experiments and data analysis have demonstrated which levels for each parameter of the lubricant resulted in the least friction. The parameters considered in the experiments are mixing ratio, number of dips and time in dips, which have varying degrees of influence on friction. The outcomes contribute to improved process efficiency and product quality within the steel industry and similar sectors. The visualization of the lubricant by UV lamp confirmed that the coating varied according to the levels of the parameters. The theoretical contribution can facilitate further research while the practical contribution provides an approach for experiments in quality improvement on lubricants. The thesis work has also identified the need for further research into the drying process after lubricant application and the use of UV lamp to improve control of lubricant smoothness.

Nonstationary signals are common in many environments such as radar, sonar, bioengineering and power systems. The nonstationary nature of the signals found in these environments means that classicalspectralanalysis techniques are notappropriate for estimating the parameters of these signals. Therefore it is important to develop techniques that can accommodate nonstationary signals. This thesis seeks to achieve this by firstly, modelling each component of the signal as having a polynomial phase and by secondly, developing techniques for estimating the parameters of these components. Several approaches can be used for estimating the parameters of polynomial phase signals, eachwithvarying degrees ofsuccess.Criteria to consider in potential estimation algorithms are (i) the signal-to-noise (SNR) ratio threshold of the algorithm, (ii) the amount of computation required for running the algorithm, and (iii) the closeness of the resulting estimates' mean-square errors to the minimum theoretical bound. These criteria will be used to compare the new techniques developed in this thesis with existing techniques. The literature on polynomial phase signal estimation highlights the recurring trade-off between the accuracy of the estimates and the amount of computation required. For example, the Maximum Likelihood (ML) method provides near-optimal estimates above threshold, but also incurs a heavy computational cost for higher order phase signals. On the other hand, multi-linear techniques such as the high-order ambiguity function (HAF) method require little computation, but have a significantly higher SNR threshold than the ML method. Of the existing techniques, the cubic phase (CP) function method is a promising technique because it provides an attractive SNR threshold and computational complexity trade-off. For this reason, the analysis techniques developed in this thesis will be derived from the CP function. A limitation of the CP function is its inability to accurately process phase orders greater than three. Therefore, the first novel contribution to this thesis develops a broadened class of discrete-time higher order phase (HP)functions to address this limitation.This broadened class is achieved by providing a multi-linear extension of the CP function. Monte Carlo simulations are performed to demonstrate the statistical advantage of the HP functions compared to the HAFs. A first order statistical analysis of the HP functions is presented. This analysis verifies the simulation results. The next novel contribution is a technique called the lower SNR cubic phase function (LCPF)method. It is an extension of the CP function, with the extension enabling performance at lower signal-to-noise ratios (SNRs). The improvement of the SNR threshold's performance is achieved by coherently integrating the CP function over a compact interval in the two-dimensional CP function space. The computation of the new algorithm is quite moderate, especially when compared to the ML method. Above threshold, the LCPF method's parameter estimates are asymptotically efficient. Monte Carlo simulation results are presented and a threshold analysis of the algorithm closely predicts the thresholds observed in these results. The next original contribution to this research involves extending the LCPF method so that it is able to process multicomponent cubic phase signals and higher order phase signals. The LCPF method is extended to higher orders by applying a windowing technique as opposed to adjusting the order of the kernel as implemented in the HP function method. To demonstrate the extension of the LCPF method for processing higher order phase signals and multicomponent cubic phase signals, some Monte Carlo simulations are presented. Finally, these estimation techniques are applied to real-worldscenarios in the fields of Power Systems Analysis, Neuroethology and Speech Analysis.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / This paper concentrates on aircraft specific issues and impacts of utilizing a "C" band telemetry system on a new or existing instrumentation system.

A criança com deficiência auditiva sensorioneural apresenta uma maior dificuldade para compreender a fala em meio ao ruído em comparação à criança normo-ouvinte. Portanto é importante considerar o uso de recursos, como o sistema de frequência modulada (FM), que auxiliam os usuários de aparelho de amplificação sonora individual (AASI) e implante coclear (IC) no reconhecimento de fala no ruído. OBJETIVO: verificar o benefício do sistema de FM em crianças com deficiência auditiva sensorioneural usuárias de AASI e/ou IC. METODOLOGIA: Participaram do estudo 30 crianças com idades entre 6 e 13 anos divididas em três grupos: grupo 1 (adaptação bimodal), grupo 2 (adaptação bilateral de AASI) e grupo controle (normo-ouvintes). Os sujeitos foram submetidos a uma avaliação do reconhecimento de fala no ruído, sendo que os sujeitos do grupo de estudo 1 e 2 foram submetidos a avaliação com e sem o sistema de FM. RESULTADOS: O sistema de FM apresentou benefícios estatisticamente significantes para os usuários de AASI e IC. A média de melhora com o sistema de FM foi de 9,7dB relação S/R para o grupo 1 e 17,2dB relação sinal/ruído para o grupo 2. A comparação com o grupo controle evidenciou que para uma criança usuária de AASI e/ou IC pode ser necessário uma melhora na relação S/R maior que 10dB a fim de alcançar o mesmo grau de reconhecimento de fala de crianças normo-ouvintes. CONCLUSÃO: O Sistema de FM beneficia crianças com deficiência auditiva usuárias de AASI e/ou IC no reconhecimento de fala no ruído. / The child with sensorineural hearing loss presents more difficulty to understand speech in noise compared with children with normal hearing. Therefore, it is important to consider the use of resources, such as the frequency modulation (FM) system, which help users of hearing aids (HA) and cochlear implants (CI) in speech recognition in noise. OBJECTIVE: verify the benefit of the FM system in children with sensorineural hearing loss users of hearing aid and/or CI. METHOD: We studied 30 children aged between 6 and 13 years divided into three groups: group 1 (bimodal fitting), group 2 (binaural fitting of hearing aids) and control group (normal hearing). The subjects were evaluated as to speech recognition in noise, and subjects of group 1 and 2 underwent evaluation with and without the FM system. RESULTS: The FM system showed statistically significant benefits for users of hearing aid and CI. The mean improvement in the FM system was 9.7 dB signal/noise ratio for group 1 and 17.2 dB signal/noise ratio for group 2. The comparison with the control group showed that for a child user of hearing aid and/or CI it may be necessary an improvement in S/N ratio greater than 10dB in order to achieve the same degree of speech recognition of normal hearing children. CONCLUSION: The FM system benefits children with hearing loss users of hearing aid and/or CI in speech.

Na escola as crianças estão envolvidas em atividades nas quais predomina a fala dos professores e de seus colegas. Deste modo, uma acústica adequada nas salas de aula e uma relação sinal-ruído (S/R) favorável são vitais para todos os alunos. Para melhorar a relação S/R a fim de favorecer o reconhecimento da fala no ruído, várias estratégias são utilizadas, incluindo a indicação dos Sistemas de Frequência Modulada (FM). Diante de indicações de sistemas FM para uso em ambientes educacionais, este estudo teve como objetivo avaliar o impacto do sistema de campo livre digital para as habilidades relacionadas ao desempenho acadêmico de indivíduos com audição periférica normal e para a voz do professor. Participaram 20 crianças com média de idade de oito anos matriculadas no 3º ano do ensino fundamental, divididas igualmente em dois grupos (controle e experimental) e seu professor. O grupo experimental foi exposto ao sistema de campo livre Digimaster 5000 e o professor utilizou o transmissor Inspiro por três meses consecutivos. Os grupos foram avaliados por meio de testes padronizados antes e após três meses de uso do equipamento, assim como a voz do professor. Os instrumentos de pesquisa utilizados para avaliação dos alunos foram os testes Perfil de Habilidades Fonológicas, Teste de Nomeação Automática Rápida (RAN), Teste de Desempenho Escolar (TDE) e Compreensão Leitora. Para avaliação da voz do professor foram aplicados: questionário, escala de desconforto do trato vocal e realizadas as análises perceptivo-auditiva e acústica. Também foram aplicados questionários e colhidos depoimentos sobre a experiência do uso do sistema de campo livre digital por parte dos alunos e do professor. Não houve diferença estatisticamente significante na comparação entre as avaliações e na comparação entre os grupos com relação ao teste Perfil de Habilidades Fonológicas e o RAN. O grupo experimental apresentou resultados estatisticamente significantes no substeste de Leitura do TDE. No teste de compreensão leitora, ambos os grupos apresentaram resultados estatisticamente significantes no tempo de leitura quando comparadas as avaliações. Na avaliação da voz do professor observou-se que na escala do desconforto do trato vocal, houve melhora do sintoma de aperto, sugerindo redução da tensão vocal. A análise perceptivo-auditiva evidenciou melhora na rouquidão e soprosidade após o uso do sistema de campo livre digital tanto na emissão da vogal /a/ quanto na contagem, e na análise acústica também observou melhora na voz. Por meio dos depoimentos e questionários sobre a experiência do uso do sistema de campo livre digital, os alunos relataram ouvir melhor o professor, e o mesmo relatou melhora na escuta e atenção dos alunos para instruções verbais. Conclui-se que o uso do sistema de campo livre digital foi efetivo para melhora no desempenho acadêmico dos alunos no teste padronizado em leitura, na melhora de inteligibilidade da fala do professor relatada pelos alunos e na redução da tensão vocal do professor. O sistema de campo livre digital minimiza o impacto do ruído em sala de aula. / At school, children are involved in activities in which the speech of teachers and classmates prevail. Thus, proper acoustics in the classrooms and a favorable signal-to-noise (S/N) ratio are vital for all students. In order to improve the S/N ratio, so as to promote the recognition of speech in noise, several strategies are used, including the use of Frequency Modulated Systems (FM). Considering the indications for use of FM systems in educational environments, this study aimed to evaluate the benefits of digital soundField system for skills related to academic performance of normal-hearing individuals and teachers voice. This study included 20 children with a mean age of eight, enrolled in the 3rd grade, equally grouped into two groups (control e experimental), and their teacher. The experimental group was exposed to Digimaster 5000 system and the teacher used the Inspiro transmitter for three consecutive months. The groups and the teachers voice were assessed through standardized tests before and after three months of using the equipment. The research tools used to evaluate the students included the Phonological Abilities Profile, Rapid Automatized Naming (RAN), Academic Performance Test (TDE) and Reading Comprehension. To evaluate the teachers voice we applied questionnaire, vocal tract discomfort scale and carried out the auditory-perceptive and acoustic analyses. We also applied specific questionnaires and collected testimonials from students and teacher on their experience of using digital soundField system. There was no statistically significant difference when comparing the evaluations nor when comparing the groups as regards the Phonological Abilities Profile and the RAN. The experimental group showed statistically significant results in the TDE reading subtest. In the reading comprehension test, both groups showed statistically significant results in the reading time. The evaluation of the teachers voice showed that, in the vocal tract discomfort scale, there was an improvement in the tight symptom, suggesting reduced vocal strain. The auditory-perceptive analysis showed improvement in hoarseness and breathiness after using the digital soundField system both in the emission of the /a/ vowel and in the counting, and in the acoustic analysis an improvement in the voice was also noted. Through testimonials and questionnaires on their experience using the digital soundField system in the classroom, the students reported they could better listen to the teacher, and the teacher reported students showed improvement in their listening and attention to verbal instructions. It is concluded that the use of digital SoundField system was effective for improving the academic performance of students in standardized testing in reading, improves speech intelligibility teacher reported by students and reducing teacher vocal strain. The digital SoundField system minimizes the impact of noise in the classroom.

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

Distributed fibre optic sensing (DFOS) is essential for structural health monitoring (SHM) of strain changes induced during the lifetime of a structure. Among different DFOS systems, the Brillouin Optical Time Domain Reflectometry (BOTDR) takes the advantages of obtaining full frequency spectrum to provide strain and temperature information along the optic fibre. The key parameters of distributed fibre optic sensors, spatial and frequency resolution, are strongly linked with the time-frequency (T-F) localisation in the system in three parts: pulse, hardware design and optical fibre. T-F localization is fundamentally important for the communication system, whereas in this study the importance of the T-F localisation to the spatial and frequency resolution, repeatability and the measurement speed are introduced in BOTDR. In this dissertation, the development of DFOS is first introduced, including both traditional methods and new developed designs. The literature review shows the signal to noise ratio (SNR) of BOTDR can be improved by investigating its T-F localisation. In the hardware design, in order to improve the T-F localisation in hardware architecture, a Short-Time Fourier Transform-Brillouin Optical Time-Domain Reflectometry (STFT-BOTDR), which implements STFT over the full frequency spectrum to measure the distributed temperature and strain along the optic fibre, is applied so that the conventional frequency sweeping method can be replaced for high resolution and fast speed measurement, providing new research advances in dynamic distributed sensing. The STFT based BOTDR has better T-F localisation, which in turn provides an opportunity for off-line post signal processing that is more adaptable for fast speed measurements. The spatial and frequency resolution of dynamic BOTDR sensing is limited by the Signal to Noise Ratio (SNR) and the T-F localization of the input pulse shape. The T-F localized input pulse shape can enhance the SNR and the spatial and frequency resolution in STFT-BOTDR. In this study, simulation and experiments of T-F localized different pulses shapes are conducted to examine the limitation of the system resolution. The result indicates that a rectangular pulse should be selected to optimize the spatial resolution and a Lorentzian pulse could be chosen to optimize the frequency resolution, while a Gaussian shape pulse can be used in general applications for its balanced performance in both spatial and frequency resolution. Meanwhile, T-F localization is used for pulse T-F localisation optimisation. A set of Kaiser-Bessel functions is used to simulate different pulse shapes and to compare their parameters in terms of T-F localisation and their Brillouin scattering spectrum. A method using an iterative filtering algorithm to achieve the optimised pulse in terms of T-F localisation is introduced to converge the Effective-pulse Width (TEW) in the time-domain and Effective-pulse Linewidth (FEL) in the frequency domain to identify the fundamental limitations. The optimised pulse can be fitted with a 7th order Gaussian (super-Gaussian) shape and it offers the best experimental performance compared to a Rectangular pulse. The sensitivity of a sensor to strain or temperature variations due to distributed Brillouin scattering is closely related to the power distribution on the Brillouin scattering spectrum which is related to the property of the optic fibre. The performance of a highly nonlinear fibre that can generate a higher Brillouin scattering signal is compared to that of a standard single mode fibre. The results show that much higher SNR of the Brillouin scattering spectrum and smaller frequency uncertainties in the sensing measurement can be achieved by using a highly nonlinear fibre for comparable launched powers. With a measurement speed of 4 Hz, the frequency uncertainty can be 0.43 MHz, corresponding to 10 με in strain or 0.43°C in temperature uncertainty for the tested highly nonlinear fibre. In contrast, for a standard single mode fibre, the value would increase to about 1.02 MHz (25 με or 1.02°C), demonstrating the advantage of the tested highly nonlinear fibre for distributed strain/temperature sensing. Results show that, by using a small effective area highly nonlinear fibre, the strain or temperature resolution can be improved because it generates stronger Brillouin scattering signal with high SNR and high Q factor spectrum, both of which determine the optimal averaging time in a single measurement. In general, the STFT-BOTDR can achieve 1 m spatial resolution, 10 με frequency resolution on a 10 km fibre with measurement speed at about 2.5 kHz.