An apparatus for the measurement of noise as a function of frequency is described. This apparatus has been used to determine the spectral distribution of the excess noise caused by the flow of a d-c. current through a resistance. The samples used for the experiments were a zinc oxide semiconductor and two metal layer resistors. The frequency region investigated was from 10 kc. to 400 kc. It was found that the excess noise in the ZnO semiconductor obeyed a 1⁄(ν₂)law at room temperature while at lower temperatures (solid CO₂ and liquid nitrogen) it was proportional to 1/ν at low frequencies and 1⁄(ν₂) high frequencies. The excess noise in the metal layer resistors was proportional to 1⁄ν at room temperatures while at 100°C there was a marked deviation from this law in the direction of a 1⁄ν₂ dependence for high frequencies. The measurements show that the 1⁄ν law gradually changes to a 1⁄ν₂ law at high frequencies in accordance with the theory proposed recently by Dr. A. van der ziel. They also indicate that the correlation times involved are a function of temperature; the exact nature of this dependence has yet to be determined. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

No description available.

Noises Off is the epitome of farce. Doors everywhere, mistaken identities, and unrequited love. The characters push themselves to the limit, both mentally and physically. They stop at nothing to put on their production and their stage manager, Timothy Allgood, becomes the babysitter of the group, which at times becomes comparable to herding cats. This document describes the journey made from casting to final bows. It contains biographical research on the playwright, Michael Frayn, as well as a historical look at the genre of farce, techniques pioneered by Sanford Meisner and Konstantin Stanislavski, along with materials, including a scored script, character analysis, personal evaluation, and rehearsal reflections.

Recently, the difficulty of placing multiple antennas onto a mobile terminal to exploit more diversity has been solved by using the cooperative communication technique, in which several relay nodes with a single antenna partner with each other to serve as virtual multiple antennas for providing the spatial diversity. Many existing researches in cooperative communication focuses on designing relay strategies to achieve better communication performance. However, most of their designs require the channel state information (CSI) being perfectly known. Unfortunately, CSI is generally unknown in practice. Therefore, before getting benefits brought by the relay-assisted network, it is necessary to obtain accurate channel state information (CSI) at the destination or relays. In this thesis, we also consider the training design for channel estimation in the AF relay network. The involvement of multiple relay nodes to exploit space diversity in cooperative communications requires sophisticated and complicated protocols, which poses a difficulty in avoiding all possible misbehaving relay nodes. Therefore, the channel estimation scheme in cooperative communication network needs to be robust against the possible relay misbehaviors. However, most prior works focused on developing channel estimation schemes by assuming perfect relayassisted communication protocol. By contrast, this work focuses on designing robust channel estimation schemes to combat the possible presence of the relay misbehaviors. Besides considering the robust design against relay misbehaviors, this work also considers more general channel model when designing the training sequence and channel estimation scheme. Specifically, in contrast to assume independent channels across relays, this thesis considers the correlated channels in both phases and the correlated noises in the first phase. Overall, the main problem of this work is to design robust channel estimation and training sequences against relay misbehaviors when the communication channels within the cooperative network are not restricted to be independent.

Made available in DSpace on 2014-06-11T19:28:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-12Bitstream added on 2014-06-13T18:57:54Z : No. of bitstreams: 1 silva_aml_me_guara.pdf: 1372198 bytes, checksum: 8bdab5df0828cfa6c6b83983a359c40b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho tem por objetivos, analisar a intensidade e freqüência dos ruídos articulares da articulação temporomandibular (A.T.M.) de indivíduos saudáveis e patológicos, auxiliar nos procedimentos clínicos e em futuras pesquisas. Para a análise dos sinais coletados foi desenvolvido um sistema para aquisição de dados, composto por um conjunto estetoscópio/microfone, equipamentos para condicionamento e aquisição de sinais e aplicativos computacionais para registro, análise e apresentação dos dados. A identificação das freqüências dominantes e o cálculo dos parâmetros considerados no domínio do tempo (valor médio, valor eficaz, desvio padrão e nível da pressão sonora – NPS) foram realizados por meio de programas computacionais específicos. Os resultados decorrentes dos cálculos e das observações em relação aos sinais obtidos, possibilitaram a determinação das faixas de freqüência, o nível da pressão sonora em decibéis (dB)* da população em estudo, além de proporcionar algumas diferenças entre os grupos patológicos e não-patológicos. Pode-se concluir que a presença da patologia influiu na amplitude dos sinais coletados, diferenciando dessa forma os casos patológicos dos não patológicos. Outra contribuição desse trabalho foi o desenvolvimento de um exame não invasivo para as Disfunções das Articulações Temporomandibulares (D.T.Ms.) / This word has the objective of analyzing the amount and frequency of articular noise in temporomandibular joint (TMJ) of both healthy and pathological individuals and aid in clinical procedures as well as in future researches. For the proposed analysis, a dada collecting system was developed comprising a stethoscope/microphone set, equipment for the signal conditioning and capturing, and computer software for data recording, analysis and presentation. The identification of dominating frequencies and the parameter calculation considered in the time period (average amount, efficient amount, linear fit, and sound pressure level) were performed through specific computer softwares. The results found through the calculations and observations in relation to the signals obtained made the determination of the frequency, the level of sound pressure (in dB) of the studied population possible besides differentiating the pathological and non-pathological groups. It can be concluded that the presence of the pathology influenced in the amplitude of the collected signals, differentiating of this form the pathological cases of the not pathological ones. Another contribution of this work was the development of a not invasive examination for the temporomandibular dysfunction (TMD)

Made available in DSpace on 2016-04-27T18:12:19Z (GMT). No. of bitstreams: 1 Michelle Barna Guzman.pdf: 1703779 bytes, checksum: 68352f5892cec094784243fe934f0b1c (MD5) Previous issue date: 2007-02-27 / Objective: Identify complaints related to the auditory health and annoyance caused by occupational and urban noises, in a firefighters corporation from Santo André county, and carry out a sound mapping from the surrounding area. Methods: A cross-sectional study was concerned in a population of 72 firefighters from the 8th brigade, being 28 from the administrative section, 20 from the occurrence center and 24 from the operational call center, using a protocol which consisted of 57 questions about personal data, auditory complaints, non-auditory complaints and annoyance. A sound mapping from the surrounding area was performed. Results: The sound pressure levels in the firefighter corporation area exceeded 67 dB (A), reaching more than 82 dB (A) in the avenue. Evaluating 72 firefighters, 95,8% are male. More than half (59,7%) have high school level. Most of them (83,3%) reported noisy work in their everyday life, being the urban noise reported as the major problem. When evaluated separately by performance section, the highest occurrence is urban noise (73,9%), firefighter vehicle noise (68,0%) and telephone noise (38,2%), in the administrative section, operational call center and occurrence center, respectively. The noisiest periods were in the morning and afternoon (45,5%), interfering in work activities for 65% of the interviewed. The most mentioned alterations were concentration (43,4%) and hearing (26,4%). Related to the hearing perception, most of them (55,6%) reported good hearing. When it comes to chemical exposure products, 55,6% reported exposure during work activities. Conclusions: Interviewed firefighters, besides noisy exposure deriving from work activities, like vehicles, walk-talk radios and telephones, are liable to consequences from the urban noise, which disturbs work activities and also causes health problems / Objetivo: Identificar queixas relacionadas à saúde auditiva e incômodo para o ruído ocupacional e urbano, em uma corporação de bombeiros do município Santo André-SP e mapeamento sonoro do entorno. Método: Tratou-se de um estudo epidemiológico transversal de inquérito na população de 72 bombeiros do 8° Grupamento sendo 28 do setor administrativo, 20 do centro de ocorrência e 24 do atendimento operacional, por meio da aplicação de um protocolo composto por 57 questões referentes a dados pessoais, queixas auditivas, não auditivas e incômodo. Foi realizado, também, o mapeamento sonoro do local. Resultados: Os níveis de pressão sonora no local da corporação ultrapassaram 67 dB (A), chegando a níveis maiores de 82 dB (A) na avenida. Dos 72 sujeitos, 95,8% são do sexo masculino. Mais da metade (59,7%) apresentou como nível de escolaridade o ensino médio. A maioria (83,3%) dos sujeitos relatou o cotidiano ruidoso no trabalho, sendo o ruído urbano citado como maior fonte. Quando vistos separadamente por área de atuação, a maior ocorrência é para ruído urbano (73,9%), ruído da viatura (68,0%) e ruído do telefone (38,2%) para o setor administrativo, divisão operacional e atendimento de ocorrências respectivamente. O período mais crítico foi manhã e tarde (45,5%), interferindo as atividades no trabalho para 65% dos sujeitos. As alterações mais citadas foram concentração (43,4%) e ouvir (26,4%). Sobre a percepção da audição, a maior parte (55,6%) referiu audição boa. Em relação à exposição a produtos químicos, 55,6% relatou exposição durante o trabalho. Conclusões: Os bombeiros analisados, além da exposição a ruídos provenientes da ocupação no ambiente de trabalho como viaturas, rádios de comunicação e telefones, também sofrem as conseqüências do ruído urbano, que altera atividades no trabalho e provoca distúrbios que foram percebidos também na saúde

Orientador: Araildo Lima da Silva / Banca: Mauro Pedro Peres / Banca: Libório José Faria Júnior / Resumo: O presente trabalho tem por objetivos, analisar a intensidade e freqüência dos ruídos articulares da articulação temporomandibular (A.T.M.) de indivíduos saudáveis e patológicos, auxiliar nos procedimentos clínicos e em futuras pesquisas. Para a análise dos sinais coletados foi desenvolvido um sistema para aquisição de dados, composto por um conjunto estetoscópio/microfone, equipamentos para condicionamento e aquisição de sinais e aplicativos computacionais para registro, análise e apresentação dos dados. A identificação das freqüências dominantes e o cálculo dos parâmetros considerados no domínio do tempo (valor médio, valor eficaz, desvio padrão e nível da pressão sonora - NPS) foram realizados por meio de programas computacionais específicos. Os resultados decorrentes dos cálculos e das observações em relação aos sinais obtidos, possibilitaram a determinação das faixas de freqüência, o nível da pressão sonora em decibéis (dB)* da população em estudo, além de proporcionar algumas diferenças entre os grupos patológicos e não-patológicos. Pode-se concluir que a presença da patologia influiu na amplitude dos sinais coletados, diferenciando dessa forma os casos patológicos dos não patológicos. Outra contribuição desse trabalho foi o desenvolvimento de um exame não invasivo para as Disfunções das Articulações Temporomandibulares (D.T.Ms.) / Abstract: This word has the objective of analyzing the amount and frequency of articular noise in temporomandibular joint (TMJ) of both healthy and pathological individuals and aid in clinical procedures as well as in future researches. For the proposed analysis, a dada collecting system was developed comprising a stethoscope/microphone set, equipment for the signal conditioning and capturing, and computer software for data recording, analysis and presentation. The identification of dominating frequencies and the parameter calculation considered in the time period (average amount, efficient amount, linear fit, and sound pressure level) were performed through specific computer softwares. The results found through the calculations and observations in relation to the signals obtained made the determination of the frequency, the level of sound pressure (in dB) of the studied population possible besides differentiating the pathological and non-pathological groups. It can be concluded that the presence of the pathology influenced in the amplitude of the collected signals, differentiating of this form the pathological cases of the not pathological ones. Another contribution of this work was the development of a not invasive examination for the temporomandibular dysfunction (TMD) / Mestre

In this work is analyzed the use of digital filter to improve the quality of a speech signal. For this purpose the influence of noises on the understanding of language is inspected and the digital filter design with optimal pole placement is presented. In the process of experimentation the speech signal was recorded by using Praat program, generated noise is made by means of Matlab function randn (n) or the sum two or one cosines. The notated speech signal is mixed with the generated noise. The algorithm based on Matlab program is created to sum up the meanings of speech signal with the corresponding meanings of the noise amplitudes. In order to improve the quality of speech signal mixed with the generated noise, the low pass, notch and strip filters is used, depending on noise, which has been used for connection of noise and a speech signal. The used programs are written down by program Matlab. In the end of the work are show the texts of the algorithms, the text of the created filters and groups of words.

Three experiments were conducted using implanted heart rate (HR) transmitters. In the first experiment three lactating Holstein cows' HR signals were monitored telemetrically for three successive days under the normal herd management. Overall mean and standard error for these cows was 76.1 ± 0.46 bpm. In the second experiment the same three cows' HR signals were monitored with a portable computer and receiver. The cows were transported 400 kilometers one way over various road surface conditions. The HR signals were monitored consecutively at the beginning of the trip and at hourly intervals during travel. The cows stayed overnight and were brought back the next day. This two-day journey was repeated one week later. As travel commenced, the cows' HRs averaged 89.7 bpm and differed significantly (p In a second experiment, two cows were exposed to five different types of aircraft noises--helicopter low altitude flyover and hover, fixed-wing low altitude flyover, jet aircraft low altitude subsonic flyover, and high altitude supersonic boom. The cows were exposed to four to five flyovers of the same type of aircraft at approximately five-minute intervals. Intervals between different aircraft type flyovers were at least one hour. Two noise disturbance experiments were conducted seven days apart. Supersonic booms and helicopter flyovers had significant effects on HR response. With increasing exposures to aircraft disturbances, there was a reduction in HR response.

We study stochastic heat equations of the forms $[\partial_t u-\sL u]\d t\d x=\lambda\int_\R\sigma(u,h)\tilde{N}(\d t,\d x,\d h),$ and $[\partial_t u-\sL u]\d t\d x=\lambda\int_{\R^d}\sigma(u,h)N(\d t,\d x,\d h)$. Here, $u(0,x)=u_0(x)$ is a non-random initial function, $N$ a Poisson random measure with its intensity $\d t\d x\nu(\d h)$ and $\nu(\d h)$ a L\'vy measure; $\tilde$ is the compensated Poisson random measure and $\sL$ a generator of a L\'{e}vy process. The function $\sigma:\R\rightarrow\R$ is Lipschitz continuous and $\lambda>0$ the noise level. The above discontinuous noise driven equations are not always easy to handle. They are discontinuous analogues of the equation introduced in \cite{Foondun} and also more general than those considered in \cite{Saint}. We do not only compare the growth moments of the two equations with each other but also compare them with growth moments of the class of equations studied in \cite{Foondun}. Some of our results are significant generalisations of those given in \cite{Saint} while the rest are completely new. Second and first growth moments properties and estimates were obtained under some linear growth conditions on $\sigma$. We also consider $\sL:=-(-\Delta)^{\alpha/2}$, the generator of $\alpha$-stable processes and use some explicit bounds on its corresponding fractional heat kernel to obtain more precise results. We also show that when the solutions satisfy some non-linear growth conditions on $\sigma$, the solutions cease to exist for both compensated and non-compensated noise terms for different conditions on the initial function $u_0(x)$. We consider also fractional heat equations of the form $ \partial_t u(t,x)=-(-\Delta)^{\alpha/2}u(t,x)+\lambda\sigma(u(t,x)\dot{F}(t,x),\,\, \text{for}\,\, x\in\R^d,\,t>0,\,\alpha\in(1,2),$ where $\dot{F}$ denotes the Gaussian coloured noise. Under suitable assumptions, we show that the second moment $\E|u(t,x)|^2$ of the solution grows exponentially with time. In particular we give an affirmative answer to the open problem posed in \cite{Conus3}: given $u_0$ a positive function on a set of positive measure, does $\sup_{x\in\R^d}\E|u(t,x)|^2$ grow exponentially with time? Consequently we give the precise growth rate with respect to the parameter $\lambda$.