Dissertations / Theses: 'Urban Acoustics'

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Yu, Chia-Jen. "Environmentally sustainable acoustics in urban residential areas." Thesis, University of Sheffield, 2008. http://etheses.whiterose.ac.uk/14922/.

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The main aim of this thesis is to examine environmentally sustainable acoustics, considering mainly urban residential areas. The study has systematically examined the three essential aspects of environmentally sustainable acoustics, namely, people, buildings and resources. The investigations are focused on three aspects: (l) the effects of urban acoustics on people: a systematic field survey on people's perceptions which considered people's living experiences, sound preferences and social factors; (2) a series of buildings' life cycle assessments which examined the environmental impact from cradle to grave of the building's lifespan and tried to further comprehend acoustic sustainability of residential buildings; (3) various possibilities concerning the use of wind turbines around and above the residential buildings in an attempt to discover how to regenerate renewable wind energy and to avoid serious noise effects. The study has then been expanded from the three aspects, by revealing potential to achieving environmentally sustainable acoustics. Overall, it has been proved that environmentally sustainable acoustics is an essential part of the environmentally sustainability development. The thesis makes a positive contribution to urban residential areas through the illustration of a sustainable acoustics approach to environmentally sustainable development, and demonstrates how these factors should be associated with each other. Acoustics and sustainability is a rather new field this study only reveals some key issues. More systematic and in-depth study in other aspects is still needed.

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Pontén, Emeli. "Acoustic Design in Urban Development : analysis of urban soundscapes and acoustic ecology research in New York City." Thesis, Högskolan Dalarna, Ljud- och musikproduktion, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:du-4836.

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The world is urbanizing rapidly with more than half of the global population now living in cities. Improving urban environments for the well-being of the increasing number of urban citizens is becoming one of the most important challenges of the 21st century. Even though it is common that city planners have visions of a ’good urban milieu’, those visions are concerning visual aesthetics or practical matters. The qualitative perspective of sound, such as sonic diversity and acoustic ecology are neglected aspects in architectural design. Urban planners and politicians are therefore largely unaware of the importance of sounds for the intrinsic quality of a place. Whenever environmental acoustics is on the agenda, the topic is noise abatement or noise legislation – a quantitative attenuation of sounds. Some architects may involve acoustical aspects in their work but sound design or acoustic design has yet to develop to a distinct discipline and be incorporated in urban planning.My aim was to investigate to what extent the urban soundscape is likely to improve if modern architectural techniques merge with principles of acoustics. This is an important, yet unexplored, research area. My study explores and analyses the acoustical aspects in urban development and includes interviews with practitioners in the field of urban acoustics, situated in New York City. My conclusion is that to achieve a better understanding of the human living conditions in mega-cities, there is a need to include sonic components into the holistic sense of urban development.

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Hirashima, Simone Queiróz da Silveira. "Percepção sonora e térmica e avaliação de conforto em espaços urbanos abertos do município de Belo Horizonte - MG, Brasil." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/16/16132/tde-23062015-172738/.

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Em espaços urbanos abertos, particularmente nas grandes cidades de climas tropicais, os pedestres estão expostos não somente a níveis sonoros elevados como também a elevadas cargas térmicas, situação que pode gerar tanto o desconforto acústico quanto o térmico. Entretanto, na maioria das vezes, a relação entre a exposição a condições acústicas e térmicas adversas e a percepção humana dessas condições são estudadas separadamente. Neste trabalho propõe-se, portanto, uma abordagem integrada para a avaliação do conforto acústico e térmico urbano e para o estudo de seus prováveis efeitos combinados. Esta pesquisa foi realizada em Belo Horizonte - MG, Brasil, cidade localizada em região de clima tropical de altitude, com verões quentes e úmidos e invernos frios e secos. Utilizou-se o método indutivo experimental na condução dos trabalhos. Dados acústicos e climáticos foram medidos simultaneamente à aplicação de formulários em dois dias representativos do verão (março/2013) e do inverno (agosto/2013), e em duas praças contrastantes em relação ao seu ambiente acústico e térmico bem como aos seus parâmetros morfológicos como o fator de visão do céu, o altura dos edifícios, o tipo de pavimento, a presença de fontes de água e vegetação. Os índices Nível de Pressão Sonora Equivalente Contínuo, ponderado na curva A (LAeq) e Temperatura Equivalente Fisiológica (PET) foram usados para representar, respectivamente, as condições acústicas e microclimáticas. Foram coletados por meio dos formulários variáveis subjetivas (percepção do volume do ambiente sonoro, avaliação de incômodo relacionado ao ambiente sonoro, avaliação de conforto acústico, percepção de sensações térmicas, preferência de sensações térmicas e avaliação de conforto térmico), variáveis individuais (vestimenta, atividade física, idade, peso, altura, sexo) e dadoscontrole, relacionados aos aspectos psicológicos, sociais e culturais que podem interferir na percepção acústica e térmica do ambiente. A amostra compreendeu aproximadamente 1.700 entrevistados. O tratamento estatístico dos dados coletados abarcou análise descritiva, correlações e regressões. Modelos de regressão logística ordinal foram utilizados para predizer as faixas de percepção acústica e térmica; e modelos de regressão logística, para predizer as faixas de conforto e desconforto acústico e térmico. Os resultados do estudo incluem, dentre outros: 1) a calibração do índice LAeq para percepção do volume sonoro - faixas: \"Baixo\", <35dB(A), \"Normal\", de 36 a 67dB(A), e \"Alto\", >68dB(A); e para avaliação de conforto acústico - faixas: \"Confortável\", <67dB(A), e \"Desconfortável\", >68dB(A); 2) a calibração do índice PET para percepção de sensações térmicas - faixas: \"Frio\", <18,9°C, \"Bem\", de 19 a 27°C, e \"Calor\", >27,1; e para avaliação de conforto térmico - faixas: \"Confortável\", de 23 a 31°C, e \"Desconfortável\", <22,9 e >31,1°C; 3) a definição das temperaturas neutra e preferida para verão (27,7 e 14,9°C) e inverno (15,9°C e 20,9°C), respectivamente, demonstrando a influência da expectativa na avaliação das condições térmicas; e 4) a comprovação de que o aumento do desconforto acústico pode acarretar (ainda que em pequena escala) o aumento do desconforto térmico e vice-versa. Estes resultados podem nortear o esclarecimento de questões referentes à percepção e ao conforto acústico e térmico em espaços urbanos, orientando as políticas públicas em projetos urbanísticos relacionados a esses temas.
In urban open public spaces, particularly in big cities of tropical climate, city-users are often exposed not only to high sound levels but also to high thermal loads, a situation that can cause both acoustic and thermal discomfort. Nevertheless, in most cases, the relationship between the exposure to each of these adverse conditions and human perceptions towards each of them are studied separately. In order to address the lack of a combined analysis of these conditions, this research has adopted an integrated approach to evaluate urban acoustic and thermal comfort and their likely combined effects. This study was carried out in in the Brazilian city of Belo Horizonte, in the state of Minas Gerais, a city located in a region of tropical of altitude climate, with hot wet summers and cold dry winters. Acoustic and climatic data were measured simultaneously with the administration of questionnaires in two representative days of summer (March/2013) and winter (August/2013), in two squares that noticeably differ in relation to their acoustic and thermal environment and their morphological parameters such as the sky view factor, the height of the buildings, the type of pavement, the presence of water sources and the vegetation. The LAeq,T and the PET index were used to represent acoustic and microclimatic conditions respectively. Subjective variables (perceived volume of the environmental sound, assessment of annoyance caused by environmental sound, acoustic comfort evaluation, perception of thermal sensation, thermal sensation preference and evaluation of thermal comfort), personal variables (clothing, physical activity, age, weight, height, gender) and control data related to psychological, social and cultural issues that might interfere with acoustic and thermal perception of the environment were collected through the questionnaires. The sample consisted of approximately 1,700 respondents. The statistical treatment of the data collected was comprised of descriptive analysis as well as analysis using correlations and regressions. Ordinal logistic regression models were used to predict the ranges of acoustic and thermal perception and logistic regression models were used to predict the ranges of acoustic and thermal comfort and discomfort. Some of the results of this study are: 1) the calibration of the LAeq index for perceived loudness - ranges: \"Low\", <35dB(A), \"Normal\", between 36 and 67dB(A), and \"High\", >68dB(A); and for evaluation of acoustic comfort - ranges: \"Comfortable\" <67dB(A), and \"Uncomfortable\", >68dB(A); 2) the calibration of the PET index for perceived thermal sensations - ranges, \"Cold\", <18.9°C, \"Well\", 19-27°C, and \"Hot\", >27.1°C; and for evaluation of thermal comfort - ranges: \"Comfortable\", 23-31°C, and \"Uncomfortable\", <22.9 and >31.1°C; 3) the definition of neutral and preferred temperatures for Summer (27.7 and 14.9°C) and Winter (15.9°C and 20.9°C), respectively, showing the influence of expectation on evaluation of thermal conditions; and 4) the confirmation that an increase of the acoustic discomfort may cause (albeit on a small scale) an increase in the thermal discomfort and vice versa. These results might shed light on the issues of acoustic and thermal perception and comfort in urban spaces, helping to guide public policies on urban projects related to these topics.

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Hewett, David Peter. "Sound propagation in an urban environment." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:e7a1d40b-2bf4-4f48-8a6b-ce6f575e955e.

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This thesis concerns the modelling of sound propagation in an urban environment. For most of the thesis a point source of sound source is assumed, and both 2D and 3D geometries are considered. Buildings are modelled as rigid blocks, with the effects of surface inhomogeneities neglected. In the time-harmonic case, assuming that the wavelength is short compared to typical lengthscales of the domain (street widths and lengths), ray theory is used to derive estimates for the time-averaged acoustic power flows through a network of interconnecting streets in the form of integrals over ray angles. In the impulsive case, the propagation of wave-field singularities in the presence of obstacles is considered, and a general principle concerning the weakening of singularities when they are diffracted by edges and vertices is proposed. The problem of switching on a time-harmonic source is also studied, and an exact solution for the diffraction of a switched on plane wave by a rigid half-line is obtained and analysed. The pulse diffraction theory is then applied in a study of the inverse problem for an impulsive source, where the aim is to locate an unknown source using Time Differences Of Arrival (TDOA) at multiple receivers. By using reflected and diffracted pulse arrivals, the standard free-space TDOA method is extended to urban environments. In particular, approximate source localisation is found to be possible even when the exact building distribution is unknown.

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Johnson, N. "The acoustics of micro hydropower : reverse Archimedean screw and the implications in urban river corridors." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/5510/.

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Brandão, Guilherme Valle Loures. "Linhas ferroviárias e cidade: avaliação acústica para redução de ruídos em áreas urbanas." Universidade Federal de Juiz de Fora (UFJF), 2018. https://repositorio.ufjf.br/jspui/handle/ufjf/7235.

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A ambiência acústica dos lugares é fator preponderante para o adequado desempenho laboral, intelectual ou simplesmente vivencial do ser humano. O local de vivência, se possuir fatores que potencializam a percepção da ambiência acústica, tais como ruído de tráfego, pode causar estresse fisiológico, contribuindo para uma avaliação qualitativa desfavorável do espaço urbano. O objeto de estudo desta pesquisa é o conjunto de características acústicas inerentes às linhas ferroviárias, que se materializam no espaço segundo esses preceitos e os irradiam ao entorno. A presença dessas linhas na malha urbana da cidade de Juiz de Fora – MG – influi diretamente na produção do espaço e direciona vetores de crescimento e valoração do solo, representando um importante aspecto a ser considerado nas políticas de produção da cidade. Este trabalho tem por objetivo identificar as características acústicas ao longo das linhas ferroviárias e suas especificidades, propondo alternativas para mitigação dos problemas verificados nas áreas adjacentes. O recorte desta pesquisa, que se insere no campo da acústica ambiental, se dá pela delimitação de estudo das características acústicas das linhas férreas, focando nas características sonoras das áreas habitadas lindeiras à faixa de domínio na malha urbana de Juiz de Fora. Com relação à metodologia de desenvolvimento, utiliza-se a Revisão Sistemática de Literatura – RSL – para definição do arcabouço teórico referencial e, para realização do estudo de caso, utiliza-se a metodologia proposta pelos referenciais normativos, através de medições in loco. O trabalho se desenvolve em seis capítulos que englobam os conhecimentos necessários à sua realização, focando na aplicação dos conceitos ao ambiente ferroviário. As análises realizadas demonstram que o ambiente acústico ao longo da linha ferroviária é drasticamente impactado pela passagem das composições, provocando o aumento do nível de ruído equivalente para além dos parâmetros normativos de conforto. A partir da situação existente, propõe-se a implantação de um misto de dispositivos convencionais e não convencionais para a redução do ruído, focando em soluções que mantenham permeabilidade visual e busquem reduzir a segregação espacial, gerando resultados que podem ser replicados em outras áreas urbanas, tanto na cidade de Juiz de Fora quanto em outras cidades. Conclui-se que a utilização dos dispositivos de proteção auxilia consideravelmente na redução do nível de pressão sonora equivalente nas áreas lindeiras, entretanto, percebe-se que é necessário o atendimento das edificações do entorno às normas construtivas para mitigação mais eficaz do problema.
Acoustic ambience is a predominant factor for adequate performance levels of work, intellect or simply experiential tasks for human beings. The vivency place itself, when possessing factors that enhance the acoustic ambience perception such as traffic noise can cause physiological stress, contributing to an unfavorable qualitative assessment of the urban space. This research’s object of study is the set of acoustic characteristics inherent to the railway lines, which materialize in space according to these precepts and radiate towards the surroundings. The presence of these railways in the Juiz de Fora city – MG – urban network directly influences the spatial production and directs land growth and valuation vectors, representing an important aspect to be considered in the city's production policies. This work aims to identify the acoustic characteristics along the railway lines and their specificities, proposing alternatives to mitigate problems observed its adjacent areas. The research clipping, which is inserted in the environmental acoustics’ field, is given by binding the study to the railway lines acoustic characteristics, focusing on the inhabited areas neighboring to the railway’s domain range sound characteristics in the Juiz de Fora city’s urban mesh. Regarding the development methodology, the systematic revision of literature method– RSL – is used to define the reference theoretical framework and, to carry out the case study, the methodology proposed by the current normative references is used, through on-the-spot measurements. The work develops in six chapters that encompass the knowledge necessary for its realization, focusing on the concept application to the railway environment. The analyses performed shows that the acoustic environment along the railway line is drastically impacted by the rail compositions passages, causing an increase in the equivalent noise level beyond the normative comfort parameters. From the existing situation, it is proposed to implement a mixture of conventional and non-conventional devices for noise reduction, focusing on solutions that maintain visual permeability and seek to reduce spatial segregation, generating results that can be replicated in other urban areas, both in Juiz de Fora and other cities. It is concluded that using protection devices greatly assists in reducing the equivalent sound pressure levels in the railway’s neighboring areas. However, it is understood that it is necessary for the surrounding buildings to meet the constructive norms for a more effective problem mitigation.

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Barros, David Alexandre Lampreia. "Analise e caracterização do ruído ambiente urbano. Cidade de Lisboa - Bairro habitacional." Master's thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/4030.

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Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia
The work of this dissertation focuses essentially on matters related to the areas of environmental acoustics – noise and discomfort to the urban population. Noise is a source of noise pollution, which is a combination of various sound sources, from commercial activities and services, religious spaces, construction, vehicle traffic, human activities, etc. This raises the level of urban noise and contributes to the emergence of unpleasant sound environments increasingly. With the evolution of society, noise is considered one of the most common environmental problems, degrading the quality of life and the environment. The legislation and international regulations have allowed the quantification by means of noise maps and acoustical prediction, where the legal authorities can view and plan interventional measures for a proper planning of the urban places. This case study describes the noise in the urban environment in the city of Lisbon, more specifically, a typical residential area of the city – Benfica – Igreja de Benfica – Rua dos Arneiros. An environmental noise analysis, through the acquisition levels of sound pressure and frequency spectra in bands 1 / 3 octave, continuously under a period of 7 (seven) days during the month of May 2011. The results showed the characteristic noise of a residential zone of the city of Lisbon, as well as identified what are their main sources. The information drawn from this study may serve as a basis for development and planning of cities in relation to acoustic comfort.

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Pasareanu, Stephanie. "A numerical hybrid method for modeling outdoor sound propagation in complex urban environments." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/47601.

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Prediction of the sound field in large urban environments has been limited thus far by the heavy computational requirements of conventional numerical methods such as boundary element (BE), finite-difference time-domain (FDTD), or ray-tracing methods. Recently, a considerable amount of work has been devoted to developing energy-based methods for this application, and results have shown the potential to compete with conventional methods. However, these developments have been limited to two-dimensional (2-D) studies (along street axes), and no real description of the phenomena at issue has been exposed (e.g., diffraction effects on the predictions). The main objectives of the present work were (i) to evaluate the feasibility of an energy-based method, the diffusion model (DM), for sound-field predictions in large, 3-D complex urban environments, (ii) to propose a numerical hybrid method that could improve the accuracy and computational time of these predictions, and (iii) to verify the proposed hybrid method against conventional numerical methods. The proposed numerical hybrid method consists of a full-wave model coupled with an energy-based model. The full-wave model is used for predicting sound propagation (i) near the source, where constructive and destructive interactions between waves are substantial, and (ii) outside the cluttered environment, where free-field-like conditions apply. The energy-based model is used in regions where diffusion conditions are met. The hybrid approach, as implemented in this work, is a combination of FDTD and DM models. Results from this work show the role played by diffraction near buildings edges close to the source and near the exterior boundaries of the computational domain, and its impact on the predictions. A wrong modeling of the diffraction effects in the environment leads to significant under or overpredictions of the sound levels in some regions, as compared to conventional numerical methods (in these regions, some differences are as high as 10 dB). The implementation of the hybrid method, verified against a full FDTD model, shows a significant improvement of the predictions. The mean error thus obtained inside the cluttered region of the environment is 1.5 dB.
Master of Science

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Heitmann, Simon. "Framtagning av en ljudanalysmetod för bedömning av ljudkvalitet i urbana utomhusmiljöer." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-358452.

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Buller är en av de miljöföroreningar som har störst negativ påverkan på männi-skors hälsa. Några av dessa eﬀekter är sömnstörningar, stress och i vissa fall kan detleda till hjärt- och kärlsjukdomar. Problematiken kring detta växer med en ökandebefolkningsmängd och urbanisering runt om i världen. Denna studie undersöker möj-ligheterna till att utveckla en ny ljudanalysmetodik för hållbara stadsmiljöer. Idag utförs traﬁkbullerutredningar som en del i miljökonsekvensbeskrivningar. Dessaanalyser innehåller i huvudsak en ljudnivåberäkning från de primära bullerkällornaoch dessa kopplas till gällande riktvärden för A-vägda ljudnivåer vid uteplatser ochfasader. Forskning kring urbana ljudmiljöer visar att endast ljudnivåerna från buller-källor inte är tillräckligt för att avgöra ljudkvaliteten. Bullrets relativa inblandning iljudmiljön, dess frekvensområde och tidsvariation samt platsens syfte och användningär faktorer som dels är kopplade till hur pass väl bullret maskeras, och dels hur passstörande ljudet faktiskt upplevs. Alla dessa faktorer behöver vägas in för att på bästasätt kunna bedöma ljudkvaliteten. Strategin som användes i denna studie bestod dels av en litteraturstudie där till-gänglig forskning kring urbana ljudmiljöer analyserades och dels i en fallstudie därtre olika typfall av urbana miljöer modellerades i det akustiska modelleringsprogram-met Olive Tree Lab. De tre fallen utgjordes av teoretiska platser, ett öppet gaturum,ett stängt gaturum samt ett gaturum med torg på ena sida. Utformningen av des-sa valdes utifrån att det är några av de vanligast förekommande urbana miljöernadär höga ljudnivåer uppstår. Utifrån litteraturstudien togs en beskrivningsmall förljudmiljöer som utgör den nya ljudanalysmetoden fram som sedan applicerades påfallstudien för analys och utvärdering. Mallens tyngdpunkt låg på att undersöka så-väl goda som negativa ljud och att koppla det till den platsen som analysen avser.Resultaten visade på att användning av mallen leder till en bredare och mer detalje-rad beskrivning av ljudmiljön som möjliggör ﬂera olika typer av lösningar än de somföreslås idag.
Noise is one of the environmental pollutions that has the largest negative eﬀect onhuman health. Some of these eﬀects are stress, sleeping issues and in some cases itcan cause cardiovascular diseases. The problem about this is growing as a result froman increasing population and an increasing urbanization. This study investigates thepossibilities to develop a new sound analysis method for urban environments. Today traﬃc noise investigations are performed as a part of environmental impact as-sessments. These analyses comprise most of sound level calculations from the primarynoise sources, which are then connected to the existing benchmarks for A-weightedsound levels at patios and facades. Research around urban sound environments showsthat only taking the sound levels exceeded from the primary noise sources in con-sideration is an insuﬃcient method for estimating the sound quality. The relativeinvolvment of the noise, the range of frequencies and the variation in time as well,as the purpose and use of the area, are factors which are all connected to how wellthe noise is masked, as well as how disturbing the noise is actually percieved as. Allthese factors have to be taken into consideration in order to assess the sound qualityin the best posssible way. The method used in this study consisted of two main parts; one literature study,where available research around urban sound environments was analysed; and onecase study where three diﬀerent cases of urban environments were analyzed in theacoustic modeling program Olive Tree Lab. The three cases consisted of theoreticallocations, one open street canyon, one closed and one street canyon with a squareon one side. Based on the literature study a description template for sound environ-ments was developed and applied to the cases from the case study for analysis andevaluation. The main focus of the template was to investigate both positive and ne-gative sounds and relate them to the site of which the sound analysis is intended for.The results showed that use of the template resulted in a broader and more detaileddescription of the sound environment, which enabled diﬀerent kinds of solutions thatare not commonly used today.

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Mendonça, André Bressa Donato. "Relações entre índices urbanísticos da forma urbana e a acústica ambiental." Universidade Federal de São Carlos, 2013. https://repositorio.ufscar.br/handle/ufscar/4368.

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Noise pollution in urban areas has been an usual problem in several Brazilian cities. However, this issue does not take into account the urban morphology and its constant changes. Therefore, sound mapping is a helping tool on the matter, allowing the prevention of sound impacts and the recognition of areas under acoustic conflicts. Applying this planning instrument, this research aims at the identification of relations between indexes of urban form and sound pressure levels achieved on street networks, specifically when considering the potential offered by the occupancy rate, the floor space index and the ratio between height and width of the urban roads. The methodology is based on the collection of physical and acoustical data, on the application of a calculation model, named NMPB-Routes 2008 and its respective validation, and on the simulation of a future scenario in the acoustic software CADNA-A. The analyzes were based on the variations of sound pressure levels, which were verified between the current scenario and the future scenario, together with the identification of the relationships between the occupancy rate, the floor space index and the H/W factor, besides the classification of the acoustics conditions of the urban blocks. The results showed that the new buildings of the future scenario contributed up to 1.0 dB (A) in the increase of the sound pressure levels at the height of ten meters above ground level. Furthermore, among the factors studied at the height of four meters, the occupancy rate is the one assuming the highest importance on the increase of sound pressure levels. On the other hand, at ten meters-high, the floor space index achieved the greatest significance in the role played on the increment of noise levels.
A poluição sonora no meio urbano tem sido um problema recorrente em muitas cidades brasileiras. Entretanto, esta problemática não leva em consideração a morfologia urbana e suas constantes modificações. Para isso, o mapeamento sonoro é uma ferramenta de grande auxílio, que permite prevenir impactos sonoros e diagnosticar áreas com conflitos acústicos já existentes. Aplicando esse recurso, essa pesquisa tem por objetivo identificar relações entre índices urbanísticos da forma urbana e os níveis de pressão sonora alcançados em redes viárias, considerando especificamente o potencial oferecido pela taxa de ocupação, índice de aproveitamento e relação entre altura e largura das vias. A metodologia é baseada em levantamento de dados físicos e acústicos do local, aplicação de um modelo de cálculo denominado NMPB-Routes 2008 e sua respectiva validação, além da simulação de um cenário futuro no software acústico CADNA-A. As análises se basearam nas variações dos níveis de pressão sonora, que foram verificadas entre o cenário atual e o cenário futuro, com a identificação das relações entre os coeficientes de ocupação, aproveitamento e da relação H/W; e, a classificação acústica das quadras urbanas. Os resultados apontaram que as novas edificações do cenário futuro contribuem com um incremento de até 1,0 dB(A) nos níveis de pressão sonora para a altura de dez metros acima do nível do solo. Verificouse também que, dentre os coeficientes estudados, o coeficiente de ocupação assume importância maior para a altura de quatro metros, influenciando no incremento dos níveis sonoros. Para alturas a dez metros acima do solo, o coeficiente de aproveitamento se revela como uma relação mais significativa no incremento dos níveis sonoros.

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De, Bort Inès. "Mesure et simulation acoustiques en milieu urbain." Electronic Thesis or Diss., Pau, 2023. http://www.theses.fr/2023PAUU3037.

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Dans cette thèse, nous proposons une méthode d'aide à la conception acoustique applicable à plusieurs échelles, allant de la salle de cours à la ville entière. Pour ce faire, nous avons développé une méthode de lancer de rayons qui permet de suivre les réflexions multiples du son dans des scènes 3D complexes.En acoustique des salles, les deux enjeux les plus courants consistent à déterminer la disposition idéale d'une certaine quantité d'absorbant acoustique et à orienter des panneaux réfléchissants dans les salles trop réverbérantes. Les paramètres acoustiques historiquement utilisés (niveau sonore, temps de réverbération, clarté) permettent de détecter les zones du public où le confort acoustique n'est pas assuré. En revanche, ils ne permettent pas toujours d'identifier les surfaces de la scène qu'il faut modifier. Dans la première application de la thèse, nous proposons un nouveau graphique panoramique qui synthétise les directions d'arrivée des réflexions multiples, sur l'ensemble des récepteurs qui constituent l'audience. Ce graphique a permis de trouver l'emplacement idéal de panneaux absorbants dans une salle de cours, et d'améliorer la forme d'un faux plafond acoustique à l'intérieur d'une chapelle. Les résultats montrent que les solutions identifiées améliorent significativement les valeurs de clarté dans les deux cas. Dans la salle de cours, le résultat a été vérifié par la mesure en présence d'un public. Dans la chapelle, un autre graphique basé sur le même principe a été utilisé pour étudier l'effet d'enveloppement acoustique (énergie latérale).En milieu urbain, les nuisances sonores ont un impact très important sur le confort et la santé des habitants. Outre la présence de nombreuses sources de bruit, les réflexions multiples entre les façades des bâtiments contribuent à l'augmentation du niveau sonore ambiant. Dans la seconde application de la thèse, nous proposons de traiter la conception d'une ville comme celle d'une salle de concert, en étudiant le rôle de la forme des bâtiments sur la propagation des réflexions sonores. Pour cela, nous inversons le graphique panoramique proposé dans la première application afin de représenter la multiplicité, non plus des récepteurs, mais des sources sonores. Le résultat peut alors se comparer à la mesure du champ par caméra acoustique. L'étude porte sur Pasaia, une petite ville portuaire du pays basque espagnol qui présente différents motifs urbains : un centre historique, de hautes tours, un port, des rues piétonnes étroites et de grandes voies de circulation. La mesure par caméra acoustique et la simulation par lancer de rayons ont permis d'identifier trois configurations urbaines distinctes. A partir de ce constat, la simulation est utilisée pour proposer différents scénarii de modification de la forme de la ville afin de réduire le niveau sonore sur les façades les plus exposées.Grâce à la simulation par lancer de rayons et à la représentation spatiale des réflexions multiples, soit sur plusieurs récepteurs soit à partir de plusieurs sources, il est possible de guider la conception de la forme et des matériaux, quelle que soit la géométrie de la scène, et de contribuer à l'approche pluridisciplinaire de la Physique Urbaine
In this thesis, we propose a method to guide the acoustic design process at different scales, from a classroom to an entire city. For this purpose, we have developed a raytracing method designed to track the multiple reflections of sound in complex 3D scenes.In room acoustics, the two most usual challenges are to determine the ideal layout for a given amount of acoustic absorber, and to orient reflective panels in excessively reverberant rooms. Traditionally, acoustic parameters (sound level, reverberation time, clarity) have been used to detect areas of the audience where acoustic comfort is not guaranteed. However, they do not systematically identify which areas of the stage need to be modified. For the first application, we propose a panoramic image that synthesizes the arrival directions of multiple reflections, on all the receivers that make up the audience. This graphic is used to find the ideal location for absorbent panels in a classroom, and to improve the shape of an acoustic false ceiling inside a chapel. The results show significant improvements in clarity values in both cases. In the classroom, the result was verified by measurement in the presence of a live audience. In the chapel, another graphic based on the same principle was used to study the acoustic envelopment effect (lateral energy).In urban environments, noise pollution has considerable impact on the comfort and health of residents. In addition to the presence of numerous noise sources, multiple reflections between building facades contribute to increasing ambient noise levels. For the second application, we propose to treat the design of a city like that of a concert hall, by studying the role of the buildings' shape on the propagation of sound reflections. Here, we invert the panoramic graph proposed in the first application to represent the multiplicity not of receivers, but of sound sources. The result can then be compared with field measurements taken with an acoustic camera. The study will examine Pasaia, a small port town in the Spanish Basque Country, which features a variety of urban patterns: a historic center, tall towers, a harbor, narrow pedestrian streets and major roadways. Acoustic camera measurements and raytracing simulation revealed three distinctive urban configurations. Based on these findings, the simulation is used to propose different scenarios for modifying the shape of the city in order to reduce noise levels on the most exposed facades.Raytracing simulation and spatial representation of multiple reflections, either on multiple receivers or from multiple sources, provide guidance for the shape and material design, regardless of the geometry of the scene and contribute to the multidisciplinary approach of Urban Physics

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Holtz, Marcos Cesar de Barros. "Avaliação qualitativa da paisagem sonora de parques urbanos. Estudo de caso : Parque Villa Lobos, em São Paulo." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/16/16132/tde-02072012-143458/.

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Neste trabalho, é apresentada uma avaliação do ambiente sonoro do Parque Villa Lobos, em São Paulo, levando em conta o contexto e a perceção humana. Aqui estão contidos mapas quantitativos clássicos, com níveis de ruído em decíbeis, e uma avaliação qualitativa do \"Soundscape\" (o ambiente sonoro, considerando o contexto e a percepção humana). É apresentado um histórico e panorama atual dos mapeamentos quantitativos e do estudo de soundscapes. Também é apresentado um histórico, descrição e situação atual do Parque em estudo. Os estudos foram baseados em medições \"in loco\", caminhadas exploratórias e levantamentos fotográficos. Estes levantamentos serviram de base para a elaboração de um mapa quantitativo global e de mapas parciais com e sem a presença das fontes sonoras em estudo. Ao final, são feitas recomendações para otimização dos soundscapes avaliados e para estudos futuros. Não são abordados os temas de mapeamento acústico para ruído comunitário, como distúrbios do sono, perturbação por excesso de ruído em residências, perda de audição ou acústica de espaços fechados em geral.
An evaluation of sound environment of the Villa Lobos Park, in São Paulo, is presented in this paper taking into account the context and human perception. This work includes classic quantitative maps, with noise levels in decibels, and a qualitative assessment of the Soundscape (the sound environment, in a context, perceived by human beings). It also presents a review of quantitative noise mapping and soundscapes. It shows a review, a description, and the current status of the Park under study. The studies were based on measurements \"in situ\", exploratory walks and photographic surveys. These surveys were the base of the development of a quantitative map, includding a global and partial maps with and without the presence of noise sources under study. Eventually, there are some recommendations to optimize the assessed soundscapes and future studies. This dissertation are not addressed to the subjects related to community noise mapping, such as sleep disturbances, annoyance in homes, hearing loss or indoor acoustic issues

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Deeley, Sabrina Maris. "Ecology of Mid-Atlantic bats after white-nose syndrome: communities, reproduction, and diet within an urban-to-rural gradient." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/104236.

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White-nose syndrome (WNS) has reduced the abundance of many bat species within the United States' mid-Atlantic region, including the endangered Indiana (Myotis sodalis), threatened Myotis septentrionalis (northern long-eared bat) and other bats of conservation concern, such as Perimyotis subflavus (tri-colored bat), Myotis leibii (eastern small-footed bat) and Myotis lucifugus (little brown bat). Impacts to Eptesicus fuscus (big brown bat) populations have been negative, positive or neutral. Migratory bat species such as Lasiurus borealis (eastern red bat) are not impacted by WNS. To determine changes within the National Park Service National Capital Region bat communities, I surveyed the area with mist netting and active acoustic sampling (2016–2018) and compared findings to pre-WNS (2003–2004) data. I documented a significant reduction in the numbers and distributions of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in Eptesicus fuscus. Documented M. septentrionalis reproduction suggests that portions of the National Capital Region may be important bat conservation areas. To explore the relationship between bat life history and passive acoustic sampling echolocation call data, as well as to review the sampling effort required to detect the presence of extant species, I used mist-netting captures and acoustic call data collected 2015 – 2018 within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. Based on locally estimated scatterplot smoothing line calculations, I determined that the highest levels of maternity season acoustic activity for Eptesicus fuscus and Lasiurus borealis corresponded primarily to lactation periods. To determine sampling effort, I developed simulations based on species accumulation curves for individual species within different physiographic regions and land-cover types. I determined that the smallest sampling efforts typically corresponded to sampling additional sites versus sampling the same sites with more nights. Detection effort varied greatly by species, physiographic region and land-cover type. Eptesicus fuscus diet has been well-studied throughout North America with visual identification methods from fecal and stomach content samples. Next-generation sequencing provides large genetic data sets analyses in a cost-effective manner and has been used to identify bat prey items. I collected Eptesicus fuscus fecal samples from mid-Atlantic regions and used next-generation sequencing to identify their prey. I documented high variation between survey areas, but did not note a clear pattern of urbanization or fragmentation impacts upon Insecta diversity. All order-level taxa that I documented had been previously documented in morphological studies; however, I did document new families, genera and species. However, I would suggest caution in using next-generation sequencing technologies as authoritative sources for documenting new diet taxa, as I noted frequent occurrences of confounding environmental DNA within the samples.
Doctor of Philosophy
White-nose syndrome (WNS) has reduced the abundance of many bat species within the United States' mid-Atlantic region, including the endangered Indiana (Myotis sodalis), threatened Myotis septentrionalis (northern long-eared bat) and other bats of conservation concern, such as the Perimyotis subflavus (tri-colored bat), Myotis leibii (eastern small-footed bat) and Myotis lucifugus (little brown bat). WNS-impacts to Eptesicus fuscus (big brown bat) populations have been negative, positive or neutral. Migratory bat species such as Lasiurus borealis (eastern red bat) are not impacted by WNS. To determine changes within the National Park Service National Capital Region bat communities, I captured bats with mist-netting techniques and recorded bat echolocation calls with active acoustics (20-minute periods; 2016–2018) and compared findings to pre-WNS (2003–2004) data. I documented a significant reduction in the numbers and distributions of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in Eptesicus fuscus. Documented M. septentrionalis reproduction suggests that portions of the National Capital Region may be important bat conservation areas. To explore the relationship between bat echolocation calls recorded with passive (over-night) acoustic data and bat reproduction trends, as well as the amount of effort required to document bat species, I sampled 849 sites with passive acoustics and 482 sites with mist-netting during 2016 – 2018 within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. I determined that the highest levels of acoustic activity for Eptesicus fuscus and Lasiurus borealis (eastern red bat) within the maternity season are associated with the period of highest levels of lactation. To determine sampling effort, I used simulations to detect species in different landscape conditions. I determined that sampling additional sites requires less sampling effort than sampling more nights. The amount of effort required to detect each bat species varied, as did the impact of different landscape conditions. Eptesicus fuscus diet has been well-studied throughout North America by identifying insect parts in feces and stomach contents. Next-generation sequencing is a process which produced large amounts of genetic data sets in a cost-effective manner, and it can be used to identify prey within bat feces. I collected Eptesicus fuscus fecal samples from mid-Atlantic regions and used next-generation sequencing to identify potential prey. I determined that bat diet varied greatly based on survey area and number of feces analyzed. At the order-level, I did not document new taxa: however, I did document new families, genera and species. However, I would suggest caution in using next-generation sequencing technologies as authoritative sources for documenting new diet taxa, as many taxa apparent within my samples were subsequently excluded, as the bats may have been incidentally ingested them.

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Molerón, Bermúdez Miguel Ángel. "Sound propagation modelling in urban areas : from the street scale to the neighbourhood scale." Thesis, Le Mans, 2012. http://www.theses.fr/2012LEMA1031/document.

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Afin de réduire le bruit dans les villes, il est nécessaire d’avoir une bonne compréhension de la propagation acoustique en milieu urbain. Il existe aujourd’hui des logiciels commerciaux qui permettent de modéliser des champs acoustiques urbains à des coûts de calcul raisonnables. Toutefois, ces outils sont basés principalement sur des approches énergétiques qui ne contiennent pas d’informations sur la phase. Pour cette raison, elles ne permettent pas la prise en compte d’effets d’interférence (par exemple, des résonances), nous offrant ainsi une description physique limitée du champacoustique. Inversement, des méthodes ondulatoires classiques (FEM, BEM, FDTD) permettent de prendre en compte ces effets. Or, en raison de la discrétisation et de la grande extension du domaine de propagation, leur utilisation est généralement limitée aux très basses fréquences.L’objectif principal de cette thèse est de développer des méthodes ondulatoires performants, dans le domaine fréquentiel et temporel, nous permettant de modéliser la propagation acoustique dans des zones urbaines étendues. L’approche proposée est basée sur une formulation mixte modale–éléments finis. L’idée clé de cette méthode estde considérer la rue comme un guide d’ondes ouvert, dont la base modale est composée de modes de fuite (modes qui rayonnent une partie de leur énergie en se propageant). Cette approche combine une description multimodale du champ acoustique dans la direction longitudinale et un calcul par éléments finis des modes propres transverses.L’approche a été mise en oeuvre précédemment à l’échelle d’une seule rue. Dans cette thèse, nous nous intéressons à l’extension de la méthode à l’échelle du quartier, afin de modéliser la propagation dans des milieux contenant un grand nombre de rues interconnectées. Une version simplifiée dans le domaine temporel, contenant uniquement lemode de propagatif le moins fuyant, est également développée.En nous basant sur ces approches, nous étudions des phénomènes ondulatoires qui peuvent apparaître dans des configurations urbaines particulières. Plus précisément, nous nous intéressons à l’interaction des modes de la rue avec des résonances dans une cour intérieure adjacente, ainsi qu’à la formation de bandes de fréquences interditesdans des réseaux périodiques de rues interconnectées. Le résultat principal de cette étude est que, malgré la forte présence de pertes par radiation dans le milieu, des effets de résonance importants peuvent encore se produire. Les résultats présentés dans ce manuscrit mettent en évidence l’importance d’une approche ondulatoire pour décrirecorrectement des champs acoustiques aux basses fréquences, et ils suggèrent l’usage potentiel de ces phénomènes afin de contrôler la propagation acoustique dans le milieu.Enfin, nous présentons une étude sur l’utilisation de métasurfaces (surfaces contenant un réseau de résonateurs) pour améliorer la performance des murs antibruit. Nous démontrons que, grâce à l’excitation des résonances locales sur la métasurface, il est possible d’obtenir des propriétés non conventionnelles, comme par exemple des angles de réflexion négatifs ou de l’absorption acoustique aux basses fréquences
The improvement of the urban sound environment requires a good understanding of the acoustic propagation in urban areas. Available commercial softwares give the possibility to simulate urban acoustic fields at relatively low computational costs. However, these tools are mainly based on energy methods that do not contain information on the phase. Therefore, these tools are unable to capture interference effects (e.g., resonances), providing a limited physical description of the acoustic field. Conversely, classical wave methods such as FEM, BEM or FDTD give the possibility to model interference effects, but their use is often restricted to very low frequencies due to discretisation and the huge extension of the propagation domain.The main goal of this thesis is to develop efficient wave methods for the acoustic propagation modelling in extended urban areas, both in the frequency and time domain. The proposed approach is based on a coupled modal–finite elements formulation. The key idea is to consider the urban canyon as an open waveguide with a modal basis composedof leaky modes, i.e., modes that radiate part of their energy into the atmosphere as they propagate. The approach combines a multimodal description of the acoustic field in the longitudinal direction and a finite elements computation of the transverseeigenmodes. This coupled approach, which has been successfully implemented at the scale of a single street, is extended in the present manuscript at a larger scale (the neighbourhood scale), in order to model problems arising in propagation domains containing many interconnected streets. A time domain version of the method, containing only the least damped mode, is also proposed.Using these methods, we investigate wave phenomena arising in specific urban configurations, as forbidden frequency bands in periodic networks of interconnected streets, and resonances in inner yards. It is found that, despite the presence of significant radiative losses in the propagation medium, strong interference effects are still observed. Not only this result highlights the relevance of a wave approach to describe accurately urban acoustic fields at low frequencies, but it suggest the potential use of these phenomena to control the acoustic propagation in urban environments.The last part of this dissertation presents a preliminary study on the use of metasurfaces (surfaces decorated with an array of resonators) to improve the performance of noise barriers. It is shown that, exciting resonances in these structures, it is possible to achieve some unconventional behaviours, including negative angles of reflection and low frequency sound absorption

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Laverne, Robert James. "Loss of Urban Forest Canopy and the Related Effects on Soundscape and Human Directed Attention." Cleveland State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=csu1483721382249909.

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Barros, Caroline Plech Gomes de. "O Impacto do ruído de canteiro de obra na qualidade acústica da circunvizinhança: estudo de caso: recorte do bairro da Jatiúca, cidade de Maceió-AL." Universidade Federal de Alagoas, 2016. http://www.repositorio.ufal.br/handle/riufal/1567.

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Due to the fast growth of cities, the society started to deal with serious environmental problems that affect directly the natural resources, infrastructure, urban conditions of the urban grid, and the still underrated sound quality of the region. Therefore, for the expansion of cities, the implementation of infrastructure and services is required, leading to increased construction works, which, in the center of the concept, are emitters of noise polluters in the environment. Under these circumstances, it is critical to monitor and evaluate the urban environment since it directly influences the general state of health. This study aims to analyze the sound impact generated by the noise produced by the construction site of a multifamily building, checking how the interaction between sound sources of the work and the urban form influences the soundscape, with a case study of a portion of the metropolitan area located in the neighborhood of Jatiúca, in the city of Maceió, Alagoas, Brazil. Physical data and measurements of the sound pressure level of the urban area during active and inactive construction were collected. The study was based on the application of software for mapping and acoustic prediction, which analyzed first the current sound setting and then the hypothetical scenarios created by changes in height, occupancy rate and number of inhabitants in the surrounding buildings. The results in measurements in situ under the influence of active work were above the permitted level by the applicable Brazilian standard, and the simulations showed that the physical traits of urban form influence the sound propagation outdoors and, therefore, the sound environment of a particular region. It is expected that this work produces benefits for future interventions in the area, creating new parameters of standards for construction, resulting in influence on the course of the proper growth of the city and the requirements for new buildings.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Devido ao crescimento acelerado das cidades e à valorização do capital influenciando na forma de construir em grandes centros urbanos, a sociedade passou a conviver com graves problemas ambientais que afetam diretamente os recursos naturais, a infraestrutura, as condicionantes urbanísticas da malha urbana e a ainda pouco valorizada qualidade sonora da região. A implantação de infraestrutura e serviços é exigida para a expansão das cidades, levando ao aumento de obras de construção civil, que, em seu cerne, são emissoras de ruídos contaminadores do meio em que se encontram. Desta forma, torna-se extremamente importante monitorar e avaliar o ambiente urbano, uma vez que ele influencia diretamente no estado geral da saúde da população. O presente trabalho tem como objetivo principal analisar o impacto gerado pelo ruído de canteiro de obra de um edifício multifamiliar, verificando de que maneira a interação entre as fontes sonoras da obra e a forma urbana exercem influência em determinado ambiente sonoro, tendo como estudo de caso uma porção da malha urbana localizada no bairro da Jatiúca, na cidade de Maceió, Alagoas, Brasil. Foram levantados dados físicos e as respectivas medições do Nível de Pressão Sonora da malha urbana com a obra ativa e inativa. O estudo foi baseado na aplicação de um software para mapeamento e predição acústica na qual se analisou, primeiramente, o cenário acústico atual e, em seguida, os cenários hipotéticos criados a partir de modificações das alturas e da taxa de ocupação dos prédios do entorno. Os resultados encontrados nas medições in loco sob a influência da obra ativa estavam acima do permitido pela norma brasileira vigente, NBR 10.151 e as simulações mostraram que as características físicas estudadas da forma urbana influenciam na propagação sonora ao ar livre e, por conseguinte, no ambiente sonoro de uma determinada região. Espera-se que este trabalho produza subsídios para futuras intervenções na área, fundamentando novos parâmetros de normas para a construção civil, acarretando uma influência no rumo do crescimento adequado da cidade e nas exigências para as novas construções.

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Gloaguen, Jean-Rémy. "Estimation du niveau sonore de sources d'intérêt au sein de mixtures sonores urbaines : application au trafic routier." Thesis, Ecole centrale de Nantes, 2018. http://www.theses.fr/2018ECDN0023/document.

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Des réseaux de capteurs acoustiques sont actuellement mis en place dans plusieurs grandes villes afin d’obtenir une description plus fine de l’environnement sonore urbain. Un des défis à relever est celui de réussir,à partir d’enregistrements sonores, à estimer des indicateurs utiles tels que le niveau sonore du trafic routier. Cette tâche n’est en rien triviale en raison de la multitude de sources sonores qui composent cet environnement. Pour cela, la Factorisation en Matrices Non-négatives (NMF) est considérée et appliquée sur deux corpus de mixtures sonores urbaines simulés. L’intérêt de simuler de tels mélanges est la possibilité de connaitre toutes les caractéristiques de chaque classe de son dont le niveau sonore exact du trafic routier. Le premier corpus consiste en 750 scènes de 30 secondes mélangeant une composante de trafic routier dont le niveau sonore est calibré et une classe de son plus générique. Les différents résultats ont notamment permis de proposer une nouvelle approche, appelée « NMF initialisée seuillée », qui se révèle être la plus performante. Le deuxième corpus créé permet de simuler des mixtures sonores plus représentatives des enregistrements effectués en villes, dont leur réalisme a été validé par un test perceptif. Avec une erreur moyenne d’estimation du niveau sonore inférieure à 1,2 dB, la NMF initialisée seuillée se révèle, là encore, la méthode la plus adaptée aux différents environnements sonores urbains. Ces résultats ouvrent alors la voie vers l’utilisation de cette méthode à d’autres sources sonores, celles que les voix et les sifflements d’oiseaux, qui pourront mener, à terme, à la réalisation de cartes de bruits multi-sources
Acoustic sensor networks are being set up in several major cities in order to obtain a more detailed description of the urban sound environment. One challenge is to estimate useful indicators such as the road traffic noise level on the basis of sound recordings. This task is by no means trivial because of the multitude of sound sources that composed this environment. For this, Non-negative Matrix Factorization (NMF) is considered and applied on two corpuses of simulated urban sound mixtures. The interest of simulating such mixtures is the possibility of knowing all the characteristics of each sound class including the exact road traffic noise level. The first corpus consists of 750 30-second scenes mixing a road traffic component with a calibrated sound level and a more generic sound class. The various results have notably made it possible to propose a new approach, called ‘Thresholded Initialized NMF', which is proving to be the most effective. The second corpus created makes it possible to simulate sound mixtures more representatives of recordings made in cities whose realism has been validated by a perceptual test. With an average noise level estimation error of less than 1.3 dB, the Thresholded Initialized NMF stays the most suitable method for the different urban noise environments. These results open the way to the use of this method for other sound sources, such as birds' whistling and voices, which can eventually lead to the creation of multi-source noise maps

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Paas, Bastian. "Micro-scale variability of atmospheric particle concentration in the urban boundary layer." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/18659.

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Für die Luftqualitätsbewertung in Städten sind Informationen zur raumzeitlichen Variabilität luftgetragener Feinstäube auf kleiner Skala von wichtiger Bedeutung. Standardisierte Messverfahren, zur Bestimmung von Partikelkonzentrationen, sind mit hohem Aufwand verbunden, weshalb dichte Messnetze fehlen. Partikelausbreitungsmodelle sind kompliziert in der Anwendung und/oder benötigen hohe Computerrechenleistung. Infolgedessen gibt es bezüglich örtlicher Partikelkonzentrationen große Informationslücken. Diese Arbeit untersucht die mikroskalige Variabilität von Aerosolen in Raum und Zeit mit unterschiedlichen Methoden. Es wurden Erhebungen mit mobilen Sensoren und eine Passantenbefragung durchgeführt. Weiterhin wurden in dieser Arbeit die physikalischen Partikeltransportmodelle ENVI-met und Austal2000 in ihrer Leistung bewertet und in angewandten Studien eingesetzt. Weiterhin wurde ein neuronales Netzwerk zur Vorhersage von Partikelkonzentrationen entwickelt. Die Untersuchungen erfolgten in den Städten Aachen und Münster. Es konnten unerwartete Verteilungsmuster hinsichtlich der Massekonzentration von Partikeln beobachtet werden. In einem innerstädtischen Park wurden diffuse Partikelquellen identifiziert, mit einem deutlichen Hinweis darauf, dass feuchtgelagerte Wegedecken einen maßgeblichen Anteil an lokalen Partikelimmissionen hatten. Weiterhin wurde Straßenverkehr als wichtiger Beitrag zum städtischen Aerosol identifiziert. Passanten, die verschiedenen Partikelkonzentrationen ausgesetzt waren, konnten diese perzeptiv nicht unterscheiden. Simulationsergebnisse von Austal2000 und ENVI-met wiesen Unterschätzungen im Vergleich zu Messwerten auf. Das entwickelte neuronale Netzwerk prognostizierte Partikelkonzentrationen teilweise mit hoher Genauigkeit. Das große Potenzial von neuronalen Netzen für die Vorhersage von Partikelkonzentrationen in räumlicher und zeitlicher Ausdehnung, auch für den Bereich der Luftqualitätsüberwachung, wurde aufgezeigt.
Knowledge about the micro-scale variability of airborne particles is a crucial criterion for air quality assessment within complex terrains such as urban areas. Due to the significant costs and time consumption related to the work required for standardized measurements of particle concentrations, dense monitoring networks are regularly missing. Models that simulate the transmission of particles are often difficult to use and/or computationally expensive. As a result, information regarding on-site particle concentrations at small scales is still limited. This thesis explores the micro-scale variability of aerosol concentrations in space and time using different methods. Experimental fieldwork, including measurements with mobile sensor equipment alongside a survey, and modeling approaches were conducted. Applied simulation studies, a performance assessment of two popular particle dispersion models, namely Austal2000 and ENVI-met, as well as the development of an ANN model are presented. The cities of Aachen and Münster were chosen as case studies for this research. Unexpected patterns of particle mass concentrations could be observed, including the identification of diffuse particle sources inside a park area with strong evidence that unpaved surfaces contributed to local aerosol concentration. In addition, vehicle traffic was proved to be a major contributor of particles, particularly close to traffic lanes. Results of the survey reveal that people were not able to distinguish between different aerosol concentration levels. Austal2000 and ENVI-met turned out to have room for improvement in terms of the reproduction of observed particle concentration levels, with both models having a tendency toward underestimation. The newly developed ANN model was confirmed to be a fairly accurate tool for predicting aerosol concentrations in both space and time, and demonstrates the principal ability of the approach also in the domain of air quality monitoring.

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Källén, Christoffer. "Acoustic Ray tracing in urban environments." Thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211160.

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This is the report of the development of a program written in MATLAB to study the propagation of sound waves using Smit’s ray tracing algorithm. The final program is able to use the data from vectorized maps to build a three-dimensional landscape and calculate the reflections at each interception point when a ray emitted from the source hits the surface of an obstacle.Another goal is to make use of all the cores, physical and logical, a modern CPU has to offer. This is to make sure the calculations are made as fast as possible. In order to meet this criteria the MATLAB Parallel Computing Toolbox is used. This requires the program code to allow for parallel execution of the code. A routine for calculation of diffraction around the building edges is also implemented. This diffraction routine was customized to suit this particular ray tracing algorithm.
Denna rapport beskriver utvecklingen av ett program skrivet i MATLAB för strålgångsberäkningar med hjälp av Smit’s algoritm. Det färdiga programmet bygger upp ett tredimensionellt landskap med vektoriserade fastighetskartor och punktmoln från laserskannade markområden som indata för beräkning av reflektioner mot mark och byggnader. För att uppnå så korta körtider som möjligt är målsättningen att utnyttja alla tillgängliga kärnor i datorns CPU med hjälp av MATLAB Parallel Computing Toolbox. Programmet beräknar även bidrag till ljudtrycksnivån genom diffraktion runt byggnader med hjälp av en modifierad version av en tillgänglig empirisk modell för diffraktion.

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Pignier, Nicolas. "Predicting the sound field from aeroacoustic sources on moving vehicles : Towards an improved urban environment." Doctoral thesis, KTH, Farkost och flyg, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-205791.

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In a society where environmental noise is becoming a major health and economical concern, sound emissions are an increasingly critical design factor for vehicle manufacturers. With about a quarter of the European population living close to roads with heavy traffic, traffic noise in urban landscapes has to be addressed first. The current introduction of electric vehicles on the market and the need for sound systems to alert their presence is causing a shift in mentalities requiring engineering methods that will have to treat noise management problems from a broader perspective. That in which noise emissions need not only be considered as a by-product of the design but as an integrated part of it. Developing more sustainable ground transportation will require a better understanding of the sound field emitted in various realistic operating conditions, beyond the current requirements set by the standard pass-by test, which is performed in a free-field. A key aspect to improve this understanding is the development of efficient numerical tools to predict the generation and propagation of sound from moving vehicles. In the present thesis, a methodology is proposed aimed at evaluating the pass-by sound field generated by vehicle acoustic sources in a simplified urban environment, with a focus on flow sound sources. Although it can be argued that the aerodynamic noise is still a minor component of the total emitted noise in urban driving conditions, this share will certainly increase in the near future with the introduction of quiet electric engines and more noise-efficient tyres on the market. This work presents a complete modelling of the problem from sound generation to sound propagation and pass-by analysis in three steps. Firstly, computation of the flow around the geometry of interest; secondly, extraction of the sound sources generated by the flow, and thirdly, propagation of the sound generated by the moving sources to observers including reflections and scattering by nearby surfaces. In the first step, the flow is solved using compressible detached-eddy simulations. The identification of the sound sources in the second step is performed using direct numerical beamforming with linear programming deconvolution, with the phased array pressure data being extracted from the flow simulations. The outcome of this step is a set of uncorrelated monopole sources. Step three uses this set as input to a propagation method based on a point-to-point moving source Green's function and a modified Kirchhoff integral under the Kirchhoff approximation to compute reflections on built surfaces. The methodology is demonstrated on the example of the aeroacoustic noise generated by a NACA air inlet moving in a simplified urban setting. Using this methodology gives insights on the sound generating mechanisms, on the source characteristics and on the sound field generated by the sources when moving in a simplified urban environment.
I ett samhälle där buller håller på att bli ett stort hälsoproblem och en ekonomisk belastning, är ljudutsläpp en allt viktigare aspekt för fordonstillverkare. Då ungefär en fjärdedel av den europeiska befolkningen bor nära vägar med tung trafik, är åtgärder för minskat trafikbuller i stadsmiljö en hög prioritet. Introduktionen av elfordon på marknaden och behovet av ljudsystem för att varna omgivningen kräver också ett nytt synsätt och tekniska angreppssätt som behandlar bullerproblemen ur ett bredare perspektiv. Buller bör inte längre betraktas som en biprodukt av konstruktionen, utan som en integrerad del av den. Att utveckla mer hållbara marktransporter kommer att kräva en bättre förståelse av det utstrålade ljudfältet vid olika realistiska driftsförhållanden, utöver de nuvarande standardiserade kraven för förbifartstest som utförs i ett fritt fält. En viktig aspekt för att förbättra denna förståelse är utvecklingen av effektiva numeriska verktyg för att beräkna ljudalstring och ljudutbredning från fordon i rörelse. I denna avhandling föreslås en metodik som syftar till att utvärdera förbifartsljud som alstras av fordons akustiska källor i en förenklad stadsmiljö, här med fokus på strömningsgenererat ljud. Även om det aerodynamiska bullret är fortfarande en liten del av de totala bullret från vägfordon i urbana miljöer, kommer denna andel säkerligen att öka inom en snar framtid med införandet av tysta elektriska motorer och de bullerreducerande däck som introduceras på marknaden. I detta arbete presenteras en komplett modellering av problemet från ljudalstring till ljudutbredning och förbifartsanalys i tre steg. Utgångspunkten är beräkningar av strömningen kring geometrin av intresse; det andra steget är identifiering av ljudkällorna som genereras av strömningen, och det tredje steget rör ljudutbredning från rörliga källor till observatörer, inklusive effekten av reflektioner och spridning från närliggande ytor. I det första steget löses flödet genom detached-eddy simulation (DES) för kompressibel strömning. Identifiering av ljudkällor i det andra steget görs med direkt numerisk lobformning med avfaltning med hjälp av linjärprogrammering, där källdata extraheras från flödessimuleringarna. Resultatet av detta steg är en uppsättning av okorrelerade akustiska monopolkällor. Steg tre utnyttjar dessa källor som indata till en ljudutbredningsmodel baserad på beräkningar punkt-till-punkt med Greensfunktioner för rörliga källor, och med en modifierad Kirchhoff-integral under Kirchhoffapproximationen för att beräkna reflektioner mot byggda ytor. Metodiken demonstreras med exemplet med det aeroakustiska ljud som genereras av ett NACA-luftintag som rör sig i en förenklad urban miljö. Med hjälp av denna metod kan man få insikter om ljudalstringsmekanismer, om källegenskaper och om ljudfältet som genereras av källor när de rör sig i en förenklad stadsmiljö.

QC 20170425

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Doc, Jean-Baptiste. "Approximations unidirectionnelles de la propagation acoustique en guide d'ondes irrégulier : application à l'acoustique urbaine." Thesis, Le Mans, 2012. http://www.theses.fr/2012LEMA1032/document.

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L'environnement urbain est le siège de fortes nuisances sonores notamment générées par les moyens de transport. Afin de lutter contre ces nuisances, la réglementation européenne impose la réalisation de cartographies de bruit. Dans ce contexte, des travaux fondamentaux sont menés autour de la propagation d'ondes acoustiques basses fréquences en milieu urbain. Différents travaux de recherche récents portent sur la mise en œuvre de méthodes ondulatoires pour la propagation d'ondes acoustiques dans de tels milieux. Le coût numérique de ces méthodes limite cependant leur utilisation dans un contexte d'ingénierie. L'objectif de ces travaux de thèse porte sur l'approximation unidirectionnelle de la propagation des ondes, appliquée à l'acoustique urbaine. Cette approximation permet d'apporter des simplifications à l'équation d'onde afin de limiter le temps de calcul lors de sa résolution. La particularité de ce travail de thèse réside dans la prise en compte des variations, continues ou discontinues, de la largeur des rues. Deux formalismes sont utilisés : l'équation parabolique et une approche multimodale. L'approche multimodale sert de support à une étude théorique sur les mécanismes de couplages de modes dans des guides d'ondes irréguliers bidimensionnels. Pour cela, le champ de pression est décomposé en fonction du sens de propagation des ondes à la manière d'une série de Bremmer. La contribution particulière de l'approximation unidirectionnelle est étudiée en fonction des paramètres géométriques du guide d'ondes, ce qui permet de mieux cerner les limites de validité de cette approximation. L'utilisation de l'équation parabolique a pour but une application à l'acoustique urbaine. Une transformation de coordonnées est associée à l'équation parabolique grand angle afin de prendre en compte l'effet de la variation de la section du guide d'ondes. Une méthode de résolution est alors spécifiquement développée et permet une évaluation précise du champ de pression. D'autre part, une méthode de résolution de l'équation parabolique grand angle tridimensionnelle est adaptée à la modélisation de la propagation acoustique en milieu urbain. Cette méthode permet de tenir compte des variations brusques ou continues de la largeur de la rue. Une comparaison avec des mesures sur maquette de rue à échelle réduite permet de mettre en avant les possibilités de la méthode
The urban environment is the seat of loud noise generated by means of transportation. To fight against these nuisances, European legislation requires the achievement of noise maps. In this context, fundamental work is carried around the propagation of acoustic low-frequency waves in urban areas. Several recent research focuses on the implementation of wave methods for acoustic wave propagation in such environments. The computational cost of these methods, however, limits their use in the context of engineering. The objective of this thesis focuses on the one-way approximation of wave propagation, applied to urban acoustics. This approximation allows to make simplifications on the wave equation in order to limit the computation time. The particularity of this thesis lies in the consideration of variations, continuous or discontinuous, of the width of streets. Two formalisms are used: parabolic equation and a multimodal approach. The multimodal approach provides support for a theoretical study on the mode-coupling mechanisms in two-dimensional irregular waveguides. For this, the pressure field is decomposed according to the direction of wave propagation in the manner of a Bremmer series. The specific contribution of the one-way approximation is studied as a function of the geometric parameters of the waveguide, which helps identify the limits of validity of this approximation. Use of the parabolic equation is intended for application to urban acoustic. A coordinate transformation is associated with the wide-angle parabolic-equation in order to take into account the variation effect of the waveguide section. A resolution method is developed specifically and allows an accurate assessment of the pressure field. On the other hand, a solving method of the three-dimensional parabolic-equation is suitable for the modeling of acoustic propagation in urban areas. This method takes into account sudden or continuous variations of the street width. A comparison with measurements on scaled model of street allows to highlight the possibilities of the method

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Dribus, John Alexander. "Characterizing Noise and Harmonicity: The Structural Function of Contrasting Sonic Components in Electronic Composition." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc30427/.

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This dissertation examines the role of noise in shaping the form of several recent musical compositions. This study demonstrates how the contrast of noisy sounds and harmonic sounds can impact the structure of compositions. Depending on context, however, the specific use and function of noise can vary substantially from one work to the next. The first portion of this paper describes methods for quantifying noise content using FFT analysis procedures. A number of tests on instrumental and synthetic sound sources are described in order to demonstrate how the analysis system may react to certain sounds. The second part of this document consists of several analyses of whole musical works. Works for acoustic instruments are examined first, followed by works for electronic media. During these analyses, it becomes clear that while the use of noise in each work is based largely upon context, some common patterns do exist across different works. The final portion of the paper examines an original work which was written with the function of noise specifically in mind. The original work is put through the same analysis procedures as works seen earlier in the paper, and some conclusions are drawn regarding both the possibilities and limitations of noise analysis as a compositional tool.

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Meng, Yan. "Acoustic simulation and auralisation in urban open spaces." Thesis, University of Sheffield, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538076.

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Choi, Bumsuk. "Acoustic source localization in 3D complex urban environments." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/27739.

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The detection and localization of important acoustic events in a complex urban environment, such as gunfire and explosions, is critical to providing effective surveillance of military and civilian areas and installations. In a complex environment, obstacles such as terrain or buildings introduce multipath propagations, reflections, and diffractions which make source localization challenging. This dissertation focuses on the problem of source localization in three-dimensional (3D) realistic urban environments. Two different localization techniques are developed to solve this problem: a) Beamforming using a few microphone phased arrays in conjunction with a high fidelity model and b) Fingerprinting using many dispersed microphones in conjunction with a low fidelity model of the environment. For an effective source localization technique using microphone phased arrays, several candidate beamformers are investigated using 2D and corresponding 3D numerical models. Among them, the most promising beamformers are chosen for further investigation using 3D large models. For realistic validation, localization error of the beamformers is analyzed for different levels of uncorrelated noise in the environment. Multiple-array processing is also considered to improve the overall localization performance. The sensitivity of the beamformers to uncertainties that cannot be easily accounted for (e.g. temperature gradient and unmodeled object) is then investigated. It is observed that evaluation in 3D models is critical to assess correctly the potential of the localization technique. The enhanced minimum variance distortionless response (EMVDR) is identified to be the only beamformer that has super-directivity property (i.e. accurate localization capability) and still robust to uncorrelated noise in the environment. It is also demonstrated that the detrimental effect of uncertainties in the modeling of the environment can be alleviated by incoherent multiple arrays. For efficient source localization technique using dispersed microphones in the environment, acoustic fingerprinting in conjunction with a diffused-based energy model is developed as an alternative to the beamforming technique. This approach is much simpler requiring only microphones rather than arrays. Moreover, it does not require an accurate modeling of the acoustic environment. The approach is validated using the 3D large models. The relationship between the localization accuracy and the number of dispersed microphones is investigated. The effect of the accuracy of the model is also addressed. The results show a progressive improvement in the source localization capabilities as the number of microphones increases. Moreover, it is shown that the fingerprints do not need to be very accurate for successful localization if enough microphones are dispersed in the environment.
Ph. D.

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Leidholdt, Hanna. "Urbana skolgårdar med god ljudmiljö : Akustiska aspekter på skolgårdens design och funktion." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-395777.

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Barn förväntas kunna leka, vila och lära sig på skolgården, men ljudnivåerna är ofta höga. Det ger upphov till frågan om ljudmiljön på skolgårdar ligger på lämpliga nivåer för dessa tre aktiviteter och hur den kan anpassas. Syftet med examensarbetet är att identifiera vad en lämplig ljudmiljö på skolgårdens olika platser är och att identifiera vilka åtgärder och designverktyg som kan användas för att förbättra ljudmiljön. Undersökning av hur och i vilken utsträckning en ljudmiljö kan modifieras för att göra den lämplig för utomhusundervisning utförs också. Examensarbetet avgränsas till grundskolor för barn mellan sex och sexton år och hur skolgården kan anpassas till barn i den åldern. Relevanta studier om hur ljud och ljudmiljö påverkar barns hälsa, inlärnings- och prestationsförmåga undersöktes för att identifiera kriterier för de tre funktionerna: (1) lek, (2) rekreation och (3) pedagogisk verksamhet. Genom att studera både forskning om den akustiska effekten av olika designverktyg och forskning om miljöer för barn identifieras akustiska designverktyg som kan användas för skolgårdar. Slutligen analyserades möjligheten att anpassa olika områden på skolgården för de tre funktionerna genom att modellera i CATT-Acoustic och genom att undersöka ljudmiljön på två befintliga innerstadsskolor som ett ljudlandskap. I CATT-Acoustic användes parametrarna efterklangstid, T20, ljudförstärkning, G, och Speech Transmission Index, STI. Resultatet var att en lämplig ljudmiljö anpassad till (1) lek kan ha en låg taltydlighet (STI mellan 0,46 och 0,66), en begränsad efterklangstid (T20 under 1,2 s) och är öppen med en ljuddämpande markyta, (2) rekreation har en kort efterklangstid T20 under 0,5 s), en begränsad ekvivalent ljudnivå Leq under 50 dBA) och absorberande eller ojämna ytor i sin omgivning och (3) undervisning bör integreras inom skolgården och bestå av platser där undervisning och annan verksamhet kan äga rum. Där föreslås T20 vara 0,5 s, Leq under 50 dBA och absorberande ytor som ger bra förutsättningar för röstkommunikation och lärande. Minst en plats föreslås vara en mötesplats som uppfyller kriterierna för undervisning som förstärker tal genom att ha en reflekterande yta placerad bakom talarens position och vara avskärmad av en absorberande vägg. Undersökningen visade att designen av skolgården och platsen för verksamheten i förhållande till skolgårdsväggarna kan förbättra ljudmiljön. Genom mjuka markmaterial (gräs, sand och grus), indelning av skolgården i flera zoner med exempelvis växtbeklädda barriärer och avskärmning från ljud utanför skolgården, kan ljudmiljön förbättras. Bullriga aktiviteter kan placeras längre bort från reflekterande ytor och ett rekreationsområde kan skapas genom absorberande ytor och diffusa skärmar. Undervisningen kan ske på många olika platser där minst en kan vara nära en reflekterande vägg som förstärker talet.
Children are expected to be able to play, rest and have lessons in schoolyards. This made me interested in investigating if the sound environment in schoolyards is at suitable levels for these three activities. The purpose of my master’s thesis was to identify what a suitable sound environment in the different areas of a schoolyard is, and to identify measures and design tools that can be used to improve the sound environment. I also investigate in what extent a sound environment can be modiﬁed to make it suitable for outdoor education. The thesis focuses on schools with six- to sixteen-year-old pupils and how children this age are affected by the sound environment. Relevant studies on how sound and the sound environment affect children’s health, learning and performance skills were examined to identify criteria for the three functions: (1) play, (2) recreation and (3) educational activities. By studying research about design tools and their acoustic effect on the one hand and studies about environments for children on the other hand I identiﬁed acoustic design tools which could be used in schoolyards. At last I analysed the possibility to adjust different areas for the three functions. I analysed the sound environment on two inner city schools as a “soundscape” and modelled sound distribution in an open space similar to inner-city schoolyards in CATT-Acoustic and used the parameters reverberance time (RT), gain (G) and Speech Transmission Index (STI). As result of this master’s thesis an appropriate sound environment in an area for (1) play has a lower speech understanding (STI between 0.46 and 0.66), has a limited reverberation time (RT under 1,2 s) and open with a sound-damping ground surface (2) recreation has a short reverbaration time (RT under 0.5 s), limited equivalent noise level (Leq under 50 dBA) and a lot of absorbent or diffuse surfaces in its surroundings (3) teaching should be integrated in the schoolyard as places where teaching and other activities can take place. There you should ﬁnd 0.5 s RT, under 50 dBA Leq and absorbent surfaces that provide good conditions for voice communication and learning. At least one place is proposed to be a meeting place that meets the criteria for teaching and ampliﬁes speech by having a reﬂective surface placed behind the speaker position and shielded by some absorbent wall. It is found that the design of the schoolyard and the location of the activities in relation to the schoolyard walls can improve the sound environment. The sound environment can be improved through especially soft ground materials (grass, sand and gravel), subdivision of the schoolyard into smaller areas, while using sound absorbing noise barriers which can be combined with planting and protect from noise from outside the schoolyard. Noisy activities can be placed further away from reﬂective areas and an area for recreation can be created through absorbent surfaces and diffuse screens. Teaching can take place in many different places where at least one of the places can be close to one reﬂective wall that ampliﬁes the speech.

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Crawford, Trent. "Exploring electroacoustic compositional structure through urban underground acoustic environments." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/16550.

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The aim and creative intent of this research project is to digitally capture the sonic fingerprint found throughout our cities’ underground transport systems with the purpose of creating new modes of compositional sound works. When arranged, these compositions will motivate and challenge ideas of what constitutes musical structure, in the context of exploring creative expression across the full electroacoustic genre. The portfolio of compositions will consist of arrangements made up from sound elements captured from within Sydney’s central business district underground rail system, and reflects an intended artistic vision explored over three distinct compositional movements. The first aim is to identify and digitally capture hi-definition stereo recordings within areas of acoustic interest. These areas include the sampling of inner-city subway platforms, rail tunnels and underground car park facilities. The focus is to sonically capture the acoustic properties and sound events occurring as a direct result of the daily human migration that accrues below the city of Sydney, with attention to recording both the existing biophony and anthrophony soundscapes. The sound recordings will then be used in exploring three individual frameworks including: how the audio recording can be used to express compositional structures; how integrating synthesis can influence new approaches in sound design; and what effects pitch and resynthesis have on the audio recordings themselves. This compositional portfolio and thesis aims to reflect a discussion of the composer’s intent, with insights into new areas of electroacoustic music production aiming to widen the framework set by traditional electronic music compositional practice, and examines links between our man-made acoustic environments, and how they can both influence and create a unique artistic vision.

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Kamrath, Matthew. "Extending standard outdoor noise propagation models to complex geometries." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1038/document.

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Les méthodes d'ingénierie acoustique (e.g. ISO 9613-2 ou CNOSSOS-EU) approchent efficacement les niveaux de bruit générés par les routes, les voies ferrées et les sources industrielles en milieu urbain. Cependant, ces approches d'ingénierie sont limitées à des géométries de forme simple, le plus souvent de section rectangulaire. Ce mémoire développe donc, et valide, une approche hybride permettant l'extension des méthodes d'ingénierie à des formes plus complexes, en introduisant un terme d’atténuation supplémentaire qui représente l'effet d'un objet réel comparé à un objet simple.Le calcul de cette atténuation supplémentaire nécessite des calculs de référence, permettant de quantifier la différence entre objets simple et complexe. Dans la mesure où il est trop onéreux, numériquement, '’effectuer ce calcul pour tous les chemins de propagation, l'atténuation supplémentaire est obtenue par interpolation de données stockées dans un tableau et évaluées pour un large jeu de positions de sources, de récepteurs et de fréquences. Dans notre approche, le calcul de référence utilise la méthode BEM en 2.5D, et permet ainsi de produire les niveaux de référence pour les géométries simple et complexe, tout en tabulant leur écart. Sur le principe, d'autres approches de référence pourraient être utilisées.Ce travail valide cette approche hybride pour un écran en forme de T avec un sol rigide, un sol absorbant et un cas avec bâtiments. Ces trois cas démontrent que l'approche hybride est plus précise que l'approche d’ingénierie standard dans des cas complexes
Noise engineering methods (e.g. ISO 9613-2 or CNOSSOS-EU) efficiently approximate sound levels from roads, railways, and industrial sources in cities. However, engineering methods are limited to only simple box-shaped geometries. This dissertation develops and validates a hybrid method to extend the engineering methods to more complicated geometries by introducing an extra attenuation term that represents the influence of a real object compared to a simplified object.Calculating the extra attenuation term requires reference calculations to quantify the difference between the complex and simplified objects. Since performing a reference computation for each path is too computationally expensive, the extra attenuation term is linearly interpolated from a data table containing the corrections for many source and receiver positions and frequencies. The 2.5D boundary element method produces the levels for the real complex geometry and a simplified geometry, and subtracting these levels yields the corrections in the table.This dissertation validates this hybrid method for a T-barrier with hard ground, soft ground, and buildings. All three cases demonstrate that the hybrid method is more accurate than standard engineering methods for complex cases

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Nabinger, Luciano Baldino. "Medições de ruído aeronáutico dentro da área II do Plano Específico de Zoneamento de Ruído do Aeroporto Salgado Filho, Porto Alegre, RS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2005. http://hdl.handle.net/10183/7962.

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Este trabalho expõe e analisa resultados de medições acústicas de aeronaves; realizadas dentro da Área II do Plano Específico de Zoneamento de Ruído- PEZR. O plano restringe o uso do solo em decorrência das emissões sonoras, oriundas da movimentação das aeronaves para cada um dos 66 aeroportos brasileiros administrados pela INFRAERO. As medições acústicas foram realizadas entre segunda e sexta feira, no período diurno (entre 7 e 22 horas) registrando um total de 697 eventos sonoros aeronáuticos, gerados por 62 modelos diferentes de aeronaves. Os procedimentos de aquisição de dados atendem a ISO 3891 (Procedimentos para descrever o ruído aeronáutico percebido no solo), e o Guia de Monitoramento de Ruído Aeronáutico, Francês, elaborado pelo Serviço Técnico da Navegação Aérea- STNA. Com o uso de softwares, discriminaram-se os Eventos Aeronáuticos (passagem de aviões) do Ruído de Fundo. Assim, quantificou-se, com razoável precisão, o impacto sonoro causado por ruído aeronáutico e definiram-se os índices: L50 (Ruído de Fundo) e o índice L1 (Eventos Aeronáuticos). São apresentados os níveis de ruído (SEL, LMáx, LMín e Leq em dB (A)) e as análises espectrais (de 10 a 20.000 Hz, relacionados às curvas NCB, presentes na NBR 12314(ABNT, 1997)), para cada tipo de aeronave registrada. Verificou-se que o Fluxo Geral tem significativa influência nos níveis de ruído emitidos e deve ser levado em consideração nas abordagens de cunho acústico, para este aeródromo. Os níveis diários de exposição ao ruído aeronáutico não atendem aos níveis recomendados pela NBR 10151 (ABNT, 2000). Também foi verificado que, no caso de se utilizar o descritor LMáx (recomendado pelas instituições internacionais, consagradas, de aviação), os índices de isolamento acústico requeridos na NBR 8572 (ABNT, 1984), não atendem aos níveis de conforto acústico, dentro de edificações, estabelecidos pela NBR 10152 (ABNT, 1987), dependendo do tipo de procedimento (pouso ou decolagem) e aeronave analisada.
The present work presents and analyzes results of acoustic measurements of aircraft, carried out within Area II of the Specific Noise Zoning Plan (PEZR). This plan restricts the use of land as a result of sound emissions originated from aircraft movement for each one of the 66 Brazilian airports administered by INFRAERO. The acoustic measurements have been taken between Monday and Friday, in the day period (between 07:00 AM and 10:00 PM), registering a total of 697 aircraft sound events, caused by 62 different aircraft models. The data acquisition procedures meet ISO 3891 (Procedures for describing the aircraft noise perceived on land), and the French Aeronautic Noise Monitoring guidebook, elaborated by STNA – Air Navigation Technical Service. By using software, the “aircraft events” (flying by aircraft) were discriminated from the background noise. Thus, with a reasonable degree of precision, the sound impact caused by aircraft noise has been quantified, and the rates have been defined: L50 (background noise) and rate L1 (aircraft events). Noise levels are presented (SEL, Lmax, Lmin and Leq in dB(A)), and the spectral analyses (from 10 to 20,000 Hz), related to NCB curves present in NBR 12314 (ABNT, 1997) for each type of registered aircraft. It has been verified that the general flow has a significant influence on the levels of issued noise, and it must be taken into consideration in the acoustic area approaches, for this airport. The daily levels of exposure to aircraft noise do not meet the levels recommended by NBR 10151 (ABNT 2000a). It was also verified that if the Lmax describer is utilized (recommended by the international aviation institutions), the acoustic insulation levels required by NBR 8572 (ABNT, 1984), do not fully meet the levels of acoustic comfort inside buildings, as set by NBR 10152 (ABNT, 1987), according to the type of analyzed aircraft.

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Holgate, Briana Kate. "Using ecoacoustic monitoring of biodiversity to inform urban development in peri-urban settings." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/133766/1/Briana_Holgate_Thesis.pdf.

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Acoustic recording has recently been identified as an effective tool for monitoring biodiversity and ecosystem health. This study used a novel approach to visually and statistically model the sounds produced within an ecosystem across space and time to identify hot spots and hot moments of biodiversity activity. It was demonstrated that biodiversity can be successfully measured through an integrated approach of ecoacoustic monitoring and highlights the potential to inform future ecological urban design decisions and conservation planning strategies.

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Leissing, Thomas. "Nonlinear acoustic wave propagation in complex media : application to propagation over urban environments." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00584398.

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Dans cette recherche, un modèle de propagation d'ondes de choc sur grandes distances sur un environnement urbain est construit et validé. L'approche consiste à utiliser l'Equation Parabolique Nonlinéaire (NPE) comme base. Ce modèle est ensuite étendu afin de prendre en compte d'autres effets relatifs à la propagation du son en milieu extérieur (surfaces non planes, couches poreuses, etc.). La NPE est résolue en utilisant la méthode des différences finies et donne des résultats en accord avec d'autres méthodes numériques. Ce modèle déterministe est ensuite utilisé comme base pour la construction d'un modèle stochastique de propagation sur environnements urbains. La Théorie de l'Information et le Principe du Maximum d'Entropie permettent la construction d'un modèle probabiliste d'incertitudes intégrant la variabilité du système dans la NPE. Des résultats de référence sont obtenus grâce à une méthode exacte et permettent ainsi de valider les développements théoriques et l'approche utilisée

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Curi, Elvys Isaias Mercado. "Metodologia de projeto de alocação de absorvedores dinâmicos para a redução de ruído emitido por transformadores de potência." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3132/tde-28032008-155724/.

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O ruído acústico produzido pelos transformadores elétricos de potência, instalados em áreas urbanas, gera problemas ambientais e desconforto na população vizinha. Neste trabalho propõe-se desenvolver uma metodologia de projeto para reduzir o ruído dos transformadores com o objetivo de atingir níveis de ruído que a legislação ambiental exige. Um transformador elétrico de potência contém um núcleo, no qual encontram-se as bobinas, dentro de um tanque, ao ativar-se o núcleo e a bobina produz ruído e vibração em todos os componentes do transformador. Para diminuir a vibração e o ruído propõe-se o uso de Absorvedores Dinâmicos (AD) fixados nas paredes do tanque, e amortecedores automotivos ligados à base do tanque. Com os amortecedores procura-se atenuar os deslocamentos da base do tanque impostos pelo núcleo. Este procedimento, isoladamente, diminui a vibração da base do tanque e das paredes do tanque. Adicionalmente, utilizando absorvedores dinâmicos de vibração, projetados e alocados de acordo com resultados de simulações numéricas, é possível reduzir a amplitude de vibração das paredes do tanque. A redução de amplitude de vibração das paredes do tanque leva necessariamente a uma redução do ruído acústico, pois o ruído acústico decorre do acoplamento da vibração das paredes com o ar vizinho. Dados de deslocamento das paredes em condições operacionais, Operational Defection Shape (ODS), foram utilizados para determinar regiões de maior vibração e regiões para alocação dos absorvedores dinâmicos. Os modelos de elementos finitos do tanque, dos absorvedores dinâmicos e o carregamento operacional permitem estimar a redução de ruído e o número e a posição dos absorvedores dinâmicos.
The acoustic noise produced by electric power transformers, installed in urban areas, generates environmental problems and discomfort for the citizens of the neighborhood. The present work proposes a design methodology of devices to reduce the acoustic noise to levels legally accepted. An electric power transformer has a core, where the coils are assembled, inside a tank to active the core and coils make sound and vibration in all transformer component. To reduce vibration and noise it is evaluate the use of Dynamic Absorbers (DA), attached to the walls of the tank, and automotive dampers, attached to the base of the tank. The shock absorbers are intended to attenuate the displacements of the base of the tank imposed by the core of the transformer. This procedure, alone, reduces the vibration amplitude of the base and of the walls of the tank. Additionally, using vibration dynamic absorbers, designed and allocated according to numerical simulations, it is possible to reduce the amplitude of vibration on the walls of the tank. The reduction of the vibration amplitude necessarily leads to a reduction of the acoustic noise, since the acoustic noise is generated through the coupling of the structural vibration and the air in the near field. Operational displacement data, from an Operational Defection Shape (ODS) analysis, were used to determine regions of vibration higher and regions to location of dynamic absorber. Finite elements models of the tank and of the dynamic absorbers and the operational loading allow the estimation of noise reduction and of the number and position of the dynamic absorbers.

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Roy, Dhrubojyoti. "From Shallow to Deep: Efficient Data-Driven Sensing on Mote-Scale Urban Radar and Acoustic Platforms." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595409507848768.

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Dedieu, Romain. "Confort acoustique dans un appartement en milieu urbain dû auxsources sonores intrusives et aux dispositions constructives dubâtiment." Thesis, CY Cergy Paris Université, 2020. http://www.theses.fr/2020CYUN1057.

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La perception de l’environnement sonore au domicile dépend des liens entre sources de bruit (provenant de l’espace public, des espaces communs et l’espace privé), des performances acoustiques des systèmes constructifs et d’autres facteurs non acoustiques tels que les aspects sociaux démographiques, la sensibilité au bruit, etc.Ces travaux de recherche suivent une approche psycho-cognitive originale. En effet, alors qu’une méthode psycho-acoustique sollicite une écoute attentive et focalisée dans un contexte maîtrisé de laboratoire permettant d’établir plus facilement des corrélations entre grandeurs physiques contrôlées et sensations, la méthode cognitive repose sur une mise en conditions proches de conditions réelles (validité écologique) dans lesquelles l’expérience perceptive contextualisée permet de corriger le biais introduit par une situation d’écoute peu représentative de la réalité. L’approche proposée reposera ainsi sur des jugements d’agréments et de confort formulés dans un contexte d’écoute active ou passive en environnement écologiquement valide.Elle sera possible par la mise en place d’un simulateur d’environnement sonore spatialisé en laboratoire qui permettra d’étudier l’effet des performances acoustiques d’éléments de construction sur le confort acoustique perçu. L’étude proposée repose au préalable sur l’analyse de l’influence des facteurs non acoustiques. Un jury sélectionné sur critères sociaux démographiques sera l’objet de trois tests et vise à mieux connaitre leur goût et leur sensibilité au bruit. Plus précisément, le premier test a pour objectif de révéler les sources de bruit jugées agréables (ou désagréables), s’il existe des consensus dans l’évaluation perceptive du jury ou bien si des différences apparaissent en raison des facteurs non-acoustiques identifiés. Lors du second test, une tâche similaire de jugement d'agrément sera demandée, portant cette fois sur des combinaisons de sources de bruit aux provenances variées (voisin, extérieur, partie commune). Il permettra d'identifier individuellement les environnements sonores confortables et inconfortables de référence qui serviront au troisième test. Le dernier test s'intéressera à un contexte de rénovation acoustique d'un ancien bâtiment simulé des années 1920-1940. L'objectif sera de mesurer l'effet d'isolements plus ou moins performants sur la gêne ressentie par le panel
The perception of the sound environment in the dwelling depends on the relations between sources of noise (from public space, common spaces and private space), the acoustic performance of construction systems and other non-acoustic factors such as demographic social aspects, noise sensitivity, etc.This research follows an original psycho-cognitive approach. Indeed, while a psycho-acoustic method is intended for attentive and focused listening in a controlled laboratory context making it easier to establish correlations between controlled physical quantities and sensations, the cognitive method is based on a simulation as close as possible to the real conditions (ecological validity. The proposed approach will thus be based on pleasantness and comfort assessments formulated in the context of active or passive listening in an ecologically valid environment.A spatialized sound environment simulator in the laboratory has been designed and set up to study the effect of the acoustic performances of construction elements on the perceived acoustic comfort. The proposed study is based first on the analysis of the influence of non-acoustic factors. A jury selected on social demographic criteria has carried out three distinct listening tests aiming to better understand their preferences and their noise sensitivity. More specifically, the objective for the first test is to find out the sources of noise deemed pleasant (or unpleasant), if there is consensus in the jury's perceptual evaluation or if differences appear due to the identified non-acoustic factors. During the second test, a similar pleasantness evaluation task will be requested, this time relating to combinations of noise sources from various sources (neighbor, exterior, common area). Thanks to these two first listening tests, a final choice of reference sound environments that will be used for the third and last test. The last test will focus on the context of acoustic renovation of an old simulated building from the 1920s and 1940s. The objective will be to measure the effect of more or less effective isolations on the perceived comfort by the panel

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Kawakita, Cristina Yukari. "Medição do ruído de tráfego na rodovia SP 270 e avaliação da satisfação quanto ao conforto acústico de seus moradores." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-30052008-105650/.

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A conscientização dos problemas que a poluição sonora acarreta e o emprego de soluções no projeto de edificações e no planejamento urbano, para amenizar tais problemas, são importantes para a melhoria da qualidade de vida do cidadão, da comunidade e da cidade. No âmbito das grandes rodovias que cortam trechos urbanizados, este estudo enfocou o conforto acústico em residências ao longo da rodovia Raposo Tavares (SP 270), a partir da análise de dados levantados por medições de grandezas acústicas, grandezas meteorológicas, contagem de fluxo de veículos, entrevistas, levantamentos físicos e fotográficos, tendo como base as normas e recomendações existentes e os procedimentos sugeridos pela metodologia de Avaliação Pós-Ocupação (APO). Verificou-se que em todos os pontos medidos, o nível contínuo médio de pressão sonora equivalente foi maior que os níveis recomendados pela norma brasileira e pela Organização Mundial de Saúde. Calculou-se a atenuação causada pelas barreiras acústicas, se estas fossem implantadas frente a residências desprotegidas e a combinação desta solução com outras tecnologias como a pavimentação porosa e o aumento do isolamento das fachadas. Com isto, foram destacadas orientações quanto ao conforto acústico na interação de projetos de implantação de moradias e vias de transporte com níveis elevados de ruído.
The awareness of the problems which the sound pollution causes and the employment of solutions in the process of building design and the urban planning, to soften such problems, are important for the improvement of the quality of life of the citizen, the community ,and the city. Within the big roads which cross urbanized areas, this study focused on the acoustic comfort, in dwellings along the Raposo Tavares road (SP 270), from the analysis of data gathered through measurements of meteorological and acoustic data, traffic flow counting, interviews, physical and photographic surveys, based on the existing standards and recommendations and the procedures suggested by the Post Occupancy Evaluation (POE). It was verified that in all the measured points, the average equivalent continuous sound pressure level was greater than the levels recommended by the Brazilian standard and the World Health Organization. It was calculated the attenuation caused by noise barriers, if they were placed in front of unprotected dwellings and the combination of this solution with other technologies such as the porous pavement and the increase of the isolation of the façades. With this, guidelines concerning the acoustic comfort in the interaction of the design of housing implantation with roads with high levels of noise were highlighted.

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Delaitre, Pauline. "Caractérisation des zones calmes en milieu urbain : qu'entendez-vous par zone calme ?" Phd thesis, Université de Cergy Pontoise, 2013. http://tel.archives-ouvertes.fr/tel-00881111.

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Depuis 2002, la directive européenne 2002/49/CE demande aux grandes villes de définir des zones calmes dans leur P.P.B.E. (Plan de Prévention du Bruit dans l'Environnement) dans le but de les préserver. L'utilisation de l'indicateur acoustique Lden est suggérée mais les états membres sont libres d'en proposer d'autres. Afin d'aider les autorités en charge de l'application de cette directive, ce travail de thèse propose une approche multidisciplinaire pour mieux définir cette notion de zone calme en milieu urbain. Une étude historique du mot calme a été réalisée à travers un corpus de dictionnaire du XVIe siècle à nos jours, pour mettre en évidence les différents sens rattachés à ce mot. Il est apparu que le lien vers le domaine sonore est tardif. De plus, la notion de calme est relative ce qui la différencie de la notion de tranquillité. Pour faire émerger les représentations actuelles, des ateliers de concertation ont été réalisés à Cergy-Pontoise et Paris. Ces deux approches ont permis de proposer des critères de caractérisation des zones calmes. Une enquête de portée nationale a ensuite été menée. Elle a permis de révéler 3 types de points de vue partagés par différents groupes de population. Pour certains, une zone calme est une zone de partage, pour d'autres une zone calme est un espace naturel et pour les derniers, une telle zone doit être silencieuse. La notion de contraste qui a émergé tout au long de ce travail a été étudiée plus en détails, à partir de test d'écoute en laboratoire et à partir des cartes de bruit. Un indicateur de contraste inspiré de la détection de contours en analyse d'image a été proposé.

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Dagallier, Adrien. "Modeling acoustic impulse arrivals for shot localization in complex environments." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEC034.

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Les systèmes de localisation acoustique existent depuis le début du XXème siècle. Les tirs d’armes à feu émettent des ondes de forte amplitude (de bouche au départ du coup, balistique générée par un projectile supersonique, éventuellement d’impact) qui se propagent à grande distance. Les capteurs acoustiques pour mesurer ces ondes sont passifs, omnidirectionnels, fonctionnels par tout temps et de faible coût. Distribués dans une zone d’intérêt, ils extraient temps d’arrivée (TOAs) ou caractéristiques fréquentielles, qui permettent de remonter à une position de source via des algorithmes de localisation et des modèles de propagation. La méthode Matching de l’équipe se démarque par l’inclusion de la physique de la propagation dans la localisation : vent, température, obstacles... Les mesures à un jeu de capteurs sont comparées à des simulations numériques de propagation depuis des sources virtuelles. Celle donnant le meilleur accord est assimilée à la source du son mesuré. En pratique, les TOAs d’une onde sur un jeu de capteurs distribués et synchrones suffisent. La base de données est simulable à l’avance, tandis que la phase de Matching est quasi - temps réel. La localisation est peu sensible au bruit, à la calibration ou aux erreurs de positionnement de capteurs. La création de la base de données est toutefois numériquement coûteuse, et le traitement de géométries et sources sonores non triviales est un défi. Les questions de l’intégration de l’environnement, de la faisabilité de la localisation de tirs d’artillerie en Matching ainsi que du Matching sur les multiples arrivées d’un même tir, se posent. L’objectif de cette thèse est de concevoir un outil de modélisation qui englobe l’acquisition de données atmosphériques et de terrain, la balistique des tirs et la propagation acoustique, afin de calculer les TOAs associés aux tirs supersoniques de manière physiquement cohérente et réaliste. Le niveau de détail de chaque physique pour la phase de Matching est aligné sur le facteur identifié comme limitant. Pour ce faire, un modèle de propagation acoustique de type Fast-Marching, baptisé IFM, est proposé. IFM conserve la généralité physique des méthodes 3D+temps, mais gagne en temps de calcul en ne calculant que les TOAs. Les géométries urbaines sont traitées par des maillages non structurés, la propagation à grande distance par des maillages curvilignes adaptés au relief. Un modèle balistique, incluant les impacts de balle dans les bâtiments ou le sol et les effets aérodynamiques 3D pour les projectiles de gros calibre, est couplé à IFM la simulation des ondes balistique et d’impact. Enfin, un couplage à des modèles de mécanique des fluides numérique et de prévision numérique du temps méso-échelle est réalisé pour la détermination de données atmosphériques pertinentes, en complément ou remplacement de mesures in-situ. L’approche est évaluée en environnement urbain via deux campagnes de mesures, avec tirs supersoniques à balles réelles. Les performances de localisation de sources ponctuelles sont excellentes avec 4 capteurs ou plus. La localisation de sniper est précise avec 6 capteurs distribués, sans visibilité directe sur le tir, ce qui est à notre connaissance une première pour du sniper. Une démonstration de l’approche en artillerie est effectuée en utilisant les arrivées multiples extraites de signaux mesurés. Grâce à la précision des simulations des TOAs des ondes de bouche, balistique et d’impact, la localisation est possible depuis des capteurs faiblement espacés, sans influence notable de la géométrie de déploiement sur la performance. Là encore, il s’agit à notre connaissance une première. Le modèle développé dans cette thèse permet d’estimer numériquement les performances de n’importe quel système de détection synchrone basé sur des TOAs, sniper comme artillerie, dans des scénarios réalistes et des environnements arbitrairement complexes. L’optimisation du placement des capteurs est ainsi envisageable
Battlefield acoustics sensing systems have been used since the early 20th century for detection and localization of threats. Artillery and gun shots emit loud sounds (muzzle blast upon firing, ballistic wave emitted by the supersonic projectile, possible impact burst) which propagate at long ranges. These sounds may be recorded at low-cost, passive, all-weather, omnidirectional sensors, usually distributed over the monitored area. Sensor data are then fused, using localization algorithms and propagation models to relate observed features, e.g. times of arrival (TOAs) or spectra, to a plausible source position. The originality of the team’s approach, through the Matching method, consists in factoring in the physics of propagation: wind and temperature effects, obstacles... A database of virtual sources acoustic features is numerically predicted at a set of sensors. Upon detection of an event, observed features are evaluated against the database. The estimated sound source position is that of the closest match. In practice, TOAs of signals at synchronous, distributed sensors are sufficient for localization of e.g., sniper shots in urban areas. The database may be generated in advance, while the Matching is potentially real-time. Localization is robust to noise, sensor positioning, calibration, or environment data errors. However, building the database is computer-intensive, and handling of non-trivial geometries or sources is challenging. Integration of environment data, feasibility of artillery shot localization and of Matching multiple arrivals, are open questions. The rationale of the present work is to develop a modeling suite, from procurement of terrain and atmosphere data, to shot ballistics and acoustic propagation, to compute TOAs of the acoustic emissions of supersonic shots in a consistent and physics-based fashion. Each time, limiting factors (sensor position error, atmospheric data accuracy, ballistic dispersion...) are determined, and all models are consequently refined, or simplified, to the befitting level of detail for the Matching phase. More specifically, a Fast-Marching acoustic propagation model is derived and implemented (IFM). IFM retains the physical generality of 3D+time solvers, while computing only TOAs and thus being much faster. IFM handles urban geometries with unstructured meshes, and long range propagation with terrain-following grids. Coupling to a ballistic model accounts for sound emissions of supersonic shots. Bullet hits in building façades or the ground and 3D aerodynamic effects for large caliber projectiles are considered. IFM is then coupled to computational fluid dynamics or meso-scale numerical weather prediction models to determine relevant atmospheric inputs in support or replacement of on-site measurements. Two measurement campaigns were conducted for evaluation of the approach in built-up areas, including supersonic weapons and actual live ammunition. Point source localization performance is state-of-the-art with down to 4 sensors. Sniper localization performs well with down to 6 sensors, including fully non-line-of-sight sensors configurations - which is to our knowledge a first for countersniper systems. Localization of artillery shots is demonstrated on the multiple arrivals of measured artillery signals, from a small baseline array, with little influence of the array geometry on the sensing performance, thanks to the accuracy of the predicted muzzle blast, ballistic wave and impact burst TOAs. Again, this is to our knowledge a first. The modeling suite developed in this work may readily assess the performance of any synchronous, TOA-based sensing system in realistic scenarii, in arbitrarily complex, nonline- of-sight environments - with a common framework for both counter-sniper and counter artillery systems. It could also be used as a decision aid, to choose the most fitting sensor configuration for surveillance of a given area, in a given scenario

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Geissner, Emilie. "Perception du bruit extérieur d'un véhicule urbain de livraison." Phd thesis, INSA de Lyon, 2006. http://tel.archives-ouvertes.fr/tel-00131513.

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Le but de cette étude était de mettre en évidence les évènements les plus désagréables lors de l'utilisation d'un véhicule urbain de livraison. Plus précisément, il s'agissait d'appliquer une méthode d'évaluation psycho-physique, la méthode d'évaluation continue analogique catégorielle, à l'évaluation du désagrément d'une séquence sonore de longue durée. Cette méthode consiste à demander à l'auditeur de déplacer un curseur coulissant continûment le long d'une échelle sur laquelle cinq catégories sont indiquées afin que la position du curseur représente à chaque instant sa perception. Dans une première partie, l'utilisation de la méthode pour l'évaluation d'un caractère complexe, le désagrément, a été validée sur des séquences sonores de synthèse. Dans une seconde partie, elle a été utilisée pour l'évaluation d'une séquence sonore réelle de livraison. En parallèle, une analyse des verbalisations libres des auditeurs a permis d'identifier des caractères sonores responsables de ce désagrément et de valider, en terme de désagrément, les résultats issus de l'évaluation continue. Deux autres applications ont été réalisées : la première étudiait l'influence de la boîte de vitesses (manuelle ou automatique) sur la perception du bruit en accélération d'un véhicule au démarrage. La seconde s'intéressait à la perception d'une séquence de livraison telle qu'un riverain peut l'entendre chez lui et non plus en extérieur. Dans une dernière partie, une expérience complémentaire a été menée pour mettre en évidence le lien entre évaluation continue et jugements globaux de la séquence de livraison.

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Connelly, Maureen Rose. "Acoustical characteristics of vegetated roofs - contributions to the ecological performance of buildings and the urban soundscape." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38090.

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The multiple benefits of vegetated roofs have been proven to reduce the adverse effects of urban densification on infrastructure, natural systems and health. However, the lack of consideration of the acoustical characteristics and benefits of vegetated roofs has limited the ability of design professionals to implement vegetated roofs as an acoustical design solution for noise mitigation and soundscape enhancement. This research, the first of its kind, addressed this problem by measuring the sound absorption and transmission characteristics of vegetated roofs, and by a case-study comparative analysis of vegetated and non-vegetated roof-top play areas. A sound absorption evaluation of substrates, using an impedance tube method, determined that substrates absorb significant sound, and that porosity, percentage of organic matter, moisture content and compaction are acoustically relevant. A multi-variable regression model, developed to optimize the specification of substrates for sound absorption, indicated that a 12.5% increase in the percentage of organic matter increased sound absorption by 9%. The spherical decoupling method was applied to measure the noise reduction coefficient (NRC) of 25 in-situ roof level test-plots with three plant communities established in viable substrate depths. The NRC of the test-plots ranged from 0.2 to 0.6. Measurements of transmission loss (TL) from an indoor-to-outdoor sound transmission lab commissioned for this research, and field evaluations of vegetated roofs of varied substrate depth, water content and plant species, confirmed that the TL values of vegetated roofs are greater than those of non-vegetated reference roofs by 10 and 20 dB in the low and mid frequencies ranges, respectively. The case-study ambient soundscape analysis of vegetated and non-vegetated rooftop play areas demonstrated that vegetated roofs alter the roof level soundscape by the effect of their sound-absorptive characteristics. Most pronounced was the introduction of sounds of birds supported by the vegetated roof habitats and the sounds generated by people interacting with vegetation on the rooftop. The findings are summarized in design guidelines and application notes for synthesis into the landscape/architectural design process.

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Sumner, Mark David. "Development of an ATV-Based Remote-Operated Sensor Platform." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/32722.

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Urban warfare is unfortunate reality of the modern world and that fact is unlikely to change in the near future. One significant danger to soldiers in an urban setting is posed by concealed snipers. The large amount of cover among densely packed buildings make snipers hard to detect by sight or sound. When a sniper fires at troops, it is imperative to positively locate the sniper as soon as possible to ensure the safety of soldiers in the field. One method of sniper detection is the use of distributed sensor nodes. These nodes may be stationary, mounted on a soldier or mounted on a vehicle. These nodes may accommodate many types of sensors, including microphones and cameras, both conventional and infrared. This project specifically deals with microphone arrays and conventional cameras mounted on a remote-operated vehicle. The purpose of this project is to demonstrate that mobile sensor platforms can be used alone or in groups to locate the source of gunshots as well as other sources of noise. The vehicle described is a recreational ATV. It has been outfitted with mechanical actuators and electronic control modules to allow the vehicle to be operated remotely. The selection and installation of these components is detailed. This includes the control of the ATVâ s steering, brakes, throttle and engine starter. The system also includes a failsafe circuit to ensure that the system will shut down if positive control is lost. An array of sensors and transducers was added to the vehicle to allow for useful data collection. This includes the aforementioned microphone array and camera. Other sensors mounted on the vehicle include a GPS antenna and an electronic compass for establishing the position and orientation of the vehicle and an accelerometer to sample engine vibration and allow for cancellation of engine noise. Once assembled, this vehicle was tested in laboratory and field environments to demonstrate its effectiveness as a mobile sensor platform. The tests showed that a microphone array could be used in combination with a camera to provide a continuous stream of images of a moving target. The test also demonstrated how a mobile acoustic node can relocate to triangulate the location of an acoustic source and thereby replicate a larger stationary network. Overall, these tests demonstrated that such a system is a feasible platform for urban combat use. Full implementation would require the fusion of several separate features, the addition of a few new features, such as semi-autonomous operation, and further field testing.
Master of Science

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LEROY, Olivia. "Estimation d'incertitudes pour la propagation acoustique en milieu extérieur." Phd thesis, UNIVERSITE DU MAINE, 2010. http://tel.archives-ouvertes.fr/tel-00906913.

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Les phénomènes de propagation acoustique en milieu extérieur sont soumis à de fortes incertitudes et à une variabilité spatio-temporelle non-négligeable. Effets de sol, phénomènes micrométéorologiques, variabilité de la source sont autant d'éléments qui agissent de façon combinée et qui rendent ainsi les phénomènes complexes. Les niveaux sonores sont alors difficilement mesurables et/ou estimés avec la précision requise d'un point de vue réglementaire et normatif. Une méthode statistique a donc été mise en place afin de pouvoir estimer ces incertitudes pour tous types de situations rencontrées : la méthode de calibration sous incertitude. Cette méthode intègre aussi bien des données modélisées que des données expérimentales ; des bases de données représentatives de sites différents plus ou moins complexes permettent d'appliquer le processus développé et de l'améliorer pas à pas. Cette méthode rend compte de la spécification du système (réflexions sur la constitution de jeux de données), la définition des observables, la calibration du système (l'écriture de la fonction coût et l'estimation des paramètres d'intérêt), la validation du système et la prévision. La méthode désormais aboutie peut être appliquée à tout type de cas d'étude dans la limite des possibilités des modèles de prévision et des données expérimentales à disposition en regard de la complexité des phénomènes ; ces limites sont également mises en évidence.

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Guillaume, Gwenaël. "Application de la méthode TLM à la modélisation de la propagation acoustique en milieu urbain." Phd thesis, Université du Maine, 2009. http://tel.archives-ouvertes.fr/tel-00793252.

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Le bruit constitue un problème sociétal majeur, en particulier en zones urbaines et périurbaines où les sources de bruit associées au traffic routier sont nombreuses et variées. Les logiciels de prévision acoustique actuels, basés sur des modèles énergétiques et géométriques et développés initialement pour des applications en milieux extérieurs faiblement bâtis, sont donc limités pour la prévision acoustique en milieux urbains et périurbains (présence de bâtis et d'encombrements, sources de bruit réelles mobiles avec un régime de fonctionnement variant dans le temps...). Le travail de thèse a consisté à proposer un modèle numérique temporel, adapté à la modélisation de la propagation acoustique en milieu urbain. Parmi les méthodes envisageables, la méthode TLM ("Transmission Line Modelling") constitue une approche originale, puisqu'elle permet de considérer des domaines de propagation de géométries complexes en intégrant la plupart des phénomènes physiques mis en jeu lors de la propagation du son sur de grandes distances (diffraction, réflexion, phénomènes stationnaires, divergence géométrique, atténuation atmosphérique, effets micrométéorologiques). Toutefois, l'étude bibliographique a mis en évidence deux limitations majeures de la méthode pour répondre pleinement à notre problématique : l'implémentation de conditions aux frontières réalistes et la modélisation d'un milieu de propagation infini. Un modèle TLM générique a ainsi été développé, et permet de réaliser des simulations en deux ou en trois dimensions en combinant l'ensemble des phénomènes influant sur la propagation du son en milieux extérieurs densément bâtis. Une approche permettant d'implémenter une condition d'impédance aux frontières a également été proposée. La méthode consiste à approcher l'impédance par une somme de systèmes linéaires du premier ordre. L'usage d'une méthode de convolution récursive permet par ailleurs de limiter le coût numérique associé au calcul du champ de pression sonore sur la frontière. Des simulations de la propagation acoustique au-dessus de différents types de sols absorbants ont été réalisées et confrontées avec succès aux solutions analytiques. Concernant la modélisation d'un milieu de propagation infini, une formulation de couches absorbantes anisotropes permettant de limiter le domaine de calcul a également été développée. Enfin, des applications réalistes de problématiques "urbaines" (écrans acoustiques, façades et terrasses végétalisées) ont finalement été proposées.

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Guilhon, Vanessa Valdez. "Adensamento habitacional na cidade de São Paulo: procedimentos para avaliação de desempenho térmico, acústico e luminoso." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/16/16132/tde-15072015-160205/.

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Esta pesquisa teve como ponto de partida o viés do adensamento em áreas urbanas consolidadas - dotadas de infraestrutura, serviços urbanos e ofertas de emprego - servindo de alternativa à expansão periférica, apresentando-se como potencial para a produção habitacional e para o adensamento construtivo. E assim, uma questão se fez pertinente: construir com o coeficiente de aproveitamento (C.A.) máximo permitido pela legislação urbana (Plano Diretor Estratégico do município de São Paulo), numa dada área da cidade, é uma garantia do atendimento da qualidade ambiental de seus edifícios? A pesquisa foi estruturada na busca por responder a esta questão. Seu objeto é a implantação dos edifícios residenciais na cidade de São Paulo, dentro do contexto de C.A. máximo permitido pela legislação. Como objetivo tem-se o estabelecimento de procedimentos para avaliação de desempenho térmico, acústico e luminoso das unidades habitacionais dos edifícios implantados na quadra de estudo, em área central da cidade de São Paulo. O método é essencialmente analítico com base na ferramenta de simulação computacional TAO: uma metodologia para implantação de edificação - ênfase no desempenho térmico, acústico, luminoso e energético (ALUCCI, 2007), para a entrada de dados e modelagem da quadra de estudo. O trabalho incluiu procedimentos de levantamento de dados primários através de pesquisa de campo. Como produto da tese tem-se: (I) critérios ambientais que orientarão as escolhas dos arquitetos quanto às distintas alternativas de implantação da edificação no terreno, (II) a flexibilização das decisões de projeto, considerando a realidade local e contemplando, principalmente, as intenções e o partido adotado pelo arquiteto, (III) ao optar por qualquer alternativa de implantação, é possível estimar o desempenho da edificação para todos os critérios de desempenho, (IV) resultados distintos do 1° e do último pavimento tipo, o que aponta a necessidade de projeto de pavimento tipo diferentes, o que ordenará o desenho do edifício, (V) metodologia para avaliação de desempenho térmico, acústico e luminoso do edifício, (VI) proposta de ocupação de quadra e avaliação de desempenho térmico, acústico e luminoso das edificações.
This research took as a starting point the densification of consolidated urban areas - with infrastructure, urban services and jobs - as an alternative to peripheral expansion, posing as potential for housing production and the constructive consolidation. So a question became relevant: Does the use of maximum Floor Area Ratio (FAR) allowed by the urban legislation (Strategic Master Plan of São Paulo) in a given area of the city ensure compliance with environmental quality of its buildings? The research was structured aiming to answer this question. The object of investigation is the implementation of the residential buildings in the city of São Paulo within the maximum FAR allowed by law. The objective has been to establish procedures for assessing thermal, acoustic and luminous performance of housing units in buildings of the study block, in the central area of São Paulo. The method is essentially analytical, based on computational simulation tool TAO: methodology for building\'s site planning to optimize thermal, acoustics, lighting and energy performance (ALUCCI, 2007), for the input of data and modeling study block. The work included collection of primary data through a field survey. As the product of the research we have: (I) environmental criteria to guide the choice of architects among different alternative for site plans, (II) the flexibility of design decisions, considering the local reality and contemplating mainly the approach adopted by the architect, (III) Once the site plan is defined it is possible to estimate the performance of the building for various criteria, (IV) different results of the 1st and last floor type, which points the need for different types of design for the ground floor, (V) methodology for evaluating thermal performance, acoustic and light of buildings, (VI) block site plan proposal and evaluation of its thermal, acoustic and luminous performance.

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Guimarães, Francisco Péricles Branco Bahiense. "Efeito da paisagem sonora na detectabilidade acústica de anuros." Universidade Católica do Salvador, 2017. http://ri.ucsal.br:8080/jspui/handle/prefix/407.

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A poluição sonora é um problema cada vez mais evidente no cotidiano das grandes cidades no mundo moderno, e o efeito desse ruído antrópico em áreas naturais e urbanas tem sido alvo de inúmeras investigações. O estudo da paisagem sonora vem se tornando uma ferramenta importante para o entendimento da dinâmica acústica ambiental. A determinação do efeito da paisagem sonora sobre a detectabilidade acústica de anuros na região metropolitana de Salvador-BA, identificando e analisando os componentes acústico da paisagem, através de gravações de áudio automatizadas. 14 anuros em atividade acústica foram identificados em duas estações distintas, seca e chuvosa. O Escalonamento multidimensional não métrico (NMS) demostrou como os componentes da paisagem sonora se organizam e relacionam com as espécies de anuros identificadas nas gravações. Nessa análise podemos observar a relação de algumas espécies de anuros com a covariante decibel (dBA), testamos modelos de detectabilidade a partir dessa variável ambiental e encontramos valores bem distintas, Pseudopaludicola mystacalis apresentou maior detectabilidade entre os anuros estudados (p = 100%), seguido do Scinax auratus (89,6%) e Leptodactylus vastus (p= 70,83%). O efeito da paisagem sonora nos anuros foi diferente para cada espécie estudada, enquanto o P.mystacalis parece não se incomodar com o nível de ruído das localidades o L. vastus mudanças comportamentais em ambiente mais ruidoso. Os estudos de Paisagens Sonoras são registros permanentes de acontecimentos de uma determinada localidade, numa determinada época. O que torna as gravações desse trabalho ferramentas importantes para analises futuras dessas duas áreas de estudos.

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Leissing, Thomas. "Propagation d'ondes non linéaires en milieu complexe - Application à la propagation en environnement urbain." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00455590.

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Dans cette recherche, un modèle de propagation d'ondes de choc sur grandes distances sur un environnement urbain est construit et validé. L'approche consiste à utiliser l'Equation Parabolique Nonlinéaire (NPE) comme base. Ce modèle est ensuite étendu afin de prendre en compte d'autres effets relatifs à la propagation du son en milieu extérieur (surfaces non planes, couches poreuses, etc.). La NPE est résolue en utilisant la méthode des différences finies et donne des résultats en accord avec d'autres méthodes numériques. Ce modèle déterministe est ensuite utilisé comme base pour la construction d'un modèle stochastique de propagation sur environnements urbains. La Théorie de l'Information et le Principe du Maximum d'Entropie permettent la construction d'un modèle probabiliste d'incertitudes intégrant la variabilité du système dans la NPE. Des résultats de référence sont obtenus grâce à une méthode exacte et permettent ainsi de valider les développements théoriques et l'approche utilisée.

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Kacem, Abbes. "Auralisation des transports ferroviaires en milieu urbain." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT049.

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Le développement du secteur des transports ferroviaires est fortement contraint par la pollution sonore associée. Le nombre de riverains gênés par le bruit ferroviaire ne cesse de croître avec la construction de nouvelles voies ferrées et la densification du trafic. Dans ce contexte, la réduction des nuisances sonores ferroviaires constitue un axe de recherche majeur. Les principaux travaux réalisés sur le sujet se sont articulés autour de l'estimation des niveaux sonores. Des modèles aussi bien théoriques qu'empiriques ont été proposés permettant de prédire avec précision les niveaux du bruit ferroviaire. Cependant, l'information fournie est difficile à appréhender en termes de gêne, cette grandeur étant aussi liée à d'autres paramètres plus complexes. Une caractérisation plus précise de la gêne consiste à simuler le signal sonore perçu par un auditeur et effectuer une évaluation par l'écoute. Cette simulation auditive du champ sonore est appelée auralisation.Cette thèse cherche à mettre en œuvre des techniques d'auralisation du bruit ferroviaire en milieu urbain. Ce bruit est de nature complexe compte tenu des nombreuses sources individuelles qui le composent. Pour une circulation urbaine, le bruit ferroviaire provient du roulement de la roue sur le rail et des équipements du train. Les travaux réalisés dans le cadre de cette thèse concernent le développement de méthodes de synthèse sonore de ces sources.Afin de pouvoir traiter différents types de roues et de rails, l'auralisation du bruit de roulement repose sur une approche physique. Cette approche consiste à modéliser l'excitation du système roue/rail dans le domaine temporel. Des modules de synthèse sonore adaptés aux contributions du rail, de la roue et des traverses sont développés. Ces modules assurent l'auralisation du bruit de roulement en tenant compte de l'excitation. La méthode proposée fait l'objet d'une étude comparative avec une mesure au passage. Il est démontré que le signal simulé est proche de la mesure en termes de niveau sonore avec un écart inférieur à 2 dB(A). Un test d'écoute basé sur les séquences simulées et enregistrées permet de mettre en évidence qu'une bonne configuration du modèle produit un réalisme important par rapport à la mesure.Par ailleurs, une technique de synthèse granulaire synchrone est adoptée pour restituer le bruit des équipements. Initialement appliqué dans la synthèse du bruit de trafic routier, l'algorithme de synthèse est adapté aux spécificités des équipements du matériel roulant ferroviaire. L’approche proposée permet de restituer fidèlement les émissions acoustiques des équipements
Railway transportation represents an important source of noise pollution in urban areas. Both the development of new infrastructures and the increase in traffic raise the number of people impacted. As a result, reduction of railway traffic noise remains an active research field. The work carried out on the subject has been mainly focused on the estimation of sound levels. Theoretical and empirical models have been proposed to accurately predict railway noise levels. However, averaged sound pressure levels may be difficult to translate in terms of perceived noise annoyance, due to the complexity of the involved phenomena. One way to assess perceived noise annoyance is to synthesize and render the time domain pressure signal perceived by a listener. Noise annoyance is then evaluated perceptually through listening tests. This approach is called auralization.The goal of this thesis is to develop auralization methods for acoustic emissions from railway vehicles in urban environments. Railway noise is radiated from many individual sources. In urban areas, the railway noise mainly consists of rolling and traction noise. This thesis focuses specifically on the audio synthesis of these sources.In order to assess different types of wheels and rails, the auralization method of the rolling noise is based on a physical model whose parameters may be varied. In this approach, the excitation of the wheel/rail system is modeled in the time domain. Three sound synthesis modules are proposed for the acoustic emission signals of the rail, wheel and sleepers. Each module accounts for the excitation force of the wheel/rail system. Comparisons of simulated pass-by noise levels with measured data show a good agreement with differences smaller than 2 dB(A) in terms of A-weighted sound pressure levels. The approach is also evaluated trough listening tests. It is shown that when properly configured, the proposed model yields very realistic sounds.Noise from the traction system components is auralized using a granular synthesis technique. The technique, previously developed for road traffic engine noise, is adapted to railway vehicle noise. It is shown to accurately synthesize the acoustic emissions of these components

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Narango, Desiree Lynn. "Causes and Consequences of Urban-associated Song Variation: A Study of Vocal Behavior in the Northern Cardinal (Cardinalis cardinalis)." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1337792731.

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Valques, Igor José Botelho. "Avaliação da qualidade ambiental acústica urbana: parametrização e quantificação das variáveis que influenciam a percepção da paisagem sonora, através da análise multivariada, no campus sede da Universidade Estadual de Maringá." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/102/102131/tde-23012017-101930/.

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A intenção desta tese é sugerir um método avaliativo, cujo índice de desempenho venha ao encontro dos indicadores da cognição de lugares, e por fim qualifique a paisagem sonora de espaços vivenciados. Pois, entende-se que a qualidade ambiental acústica dos lugares pode ser quantificada a fim de facilitar o seu entendimento. Nesse ideário, este trabalho visou, estabelecer a interação dos fatores perceptivos do usuário com os atributos físicos da paisagem sonora relacionando-os segundo o referencial teórico: soundscape. Defendeu-se que a qualidade sonora das ambiências urbanas seja resultado da avaliação da inerência acústica da envoltória ambiental do espaço vivenciado. Buscou-se, nesse sentido, parâmetros que a fizessem mensurável, para apreender a empatia ou a repulsa às ambiências sonoras de certos locais, ou seja, a aceitação ou a recusa de suas características acústicas intrínsecas e perceptivas. O método avaliativo foi aplicado nas ambiências acústicas do campus sede da UEM, e foi balizado com a análise estatística multivariada de critérios de desempenho acústico qualitativos e quantitativos. Foram determinados todos os atributos e, valorados com a finalidade de determinar o ranking das ambiências estudadas. Finalmente, conseguiu-se as áreas qualificadas e hierarquizadas que podem auxiliar em uma tomada de decisão para futuras adequações do plano diretor do campus sede, fato que, possivelmente, norteará também adequações dos outros sete campi da UEM. Assim, através da metodologia proposta avaliou-se a qualidade acústica de parte do campus sede da Universidade Estadual de Maringá UEM, como também, validou-se a exequibilidade do método. Entendeu-se que o espaço de um campus universitário deva proporcionar ambiências sonoras de qualidade para a tríade pedagógica: ensino, pesquisa e extensão. Portanto, esta pesquisa justifica-se, pois, vem ao encontro dessa necessidade, haja visto que a ambientação sonora dos lugares de trabalho é extremamente importante ao desempenho e a vivência de qualidade. Abre-se uma porta que identifica o potencial de verificação da paisagem sonora como norteador para o planejamento espacial urbano, além de ajudar na compreensão de como as cidades e os seus lugares satisfazem, ou não a expectativa de seus habitantes.
The intention of this thesis is to suggest an evaluation method, where performance index must meet the indicators of cognition places, and finally qualify the soundscape of experienced spaces. Therefore, it is understood that the acoustic environmental quality of the places can be quantified in order to facilitate their understanding. In this ideology, this work aims to establish the interaction of perceptual user factors with the physical attributes of soundscape relating them according to the theoretical framework: soundscape.It was argued that the sound quality of urban ambiance is a result of evaluation of acoustic inherent environmental envelope of the experienced space. Looking for this direction, parameters that made measurable, to learn empathy or disgust to sound ambiences of certain sites, or the acceptance or refusal of their intrinsic perceptual and acoustic characteristics. It was proposed that the evaluation method is applied to the acoustic ambiance of the campus headquarters of UEM is based on multivariate statistical analysis of qualitative and quantitative acoustic performance criteria. Thus, all the attributes were determined and rated for the purpose of determining the ranking of the studied ambiences. Finally, they were qualified and prioritized areas that may assist in a decision-making for future adjustments of the master plan of the campus headquarters, a fact that possibly also will guide adjustments of seven other campuses of UEM. Thus, through the proposed methodology evaluated the acoustical quality of the headquarters campus of the State University of Maringa - UEM, but also validated to the feasibility of the method. It is understood that the area of a university campus should provide ambiance sound quality for pedagogical triad: teaching, research and extension. Therefore, this research is justified once it meets this need, due to the fact that the sound ambience of workplaces is extremely important to the performance and the experience of quality. A door that identifies the potential to check the soundscape as a guide for urban spatial planning it opens and helps in understanding how cities and their seats meet or not the expectations of its inhabitants.

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Гуменюк, Інна Леонідівна, and Inna Leonidivna Humeniuk. "Варіювання тривалості звучання англомовних міських пейзажних описів." Academic Society of Michal Baldyansky, Ukrainian Association of Scientists of Economics, Bratislava, Slovak Republic, 2016. http://repository.sspu.edu.ua/handle/123456789/8833.

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Результати, описані у тезах доповіді, стосуються експериментальної фонетики, зокрема інтонології.
У праці подано результати акустичного аналізу тривалості звучання англомовних міських пейзажних описів.
The paper highlights the results of acoustic analysis. The sound duration of English urban landscape descriptions was analyzed.

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Vuylsteke, Xavier. "Development of a reference method based on the fast multipole boundary element method for sound propagation problems in urban environments : formalism, improvements & applications." Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1174/document.

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Décrit comme l'un des algorithmes les plus prometteurs du 20ème siècle, le formalisme multipolaire appliqué à la méthode des éléments de frontière, permet de nos jours de traiter de larges problèmes encore inconcevables il y a quelques années. La motivation de ce travail de thèse est d'évaluer la capacité, ainsi que les avantages concernant les ressources numériques, de ce formalisme pour apporter une solution de référence aux problèmes de propagation sonore tri-dimensionnels en environnement urbain, dans l'objectif d'améliorer les algorithmes plus rapides déjà existants. Nous présentons la théorie nécessaire à l'obtention de l'équation intégrale de frontière pour la résolution de problèmes non bornés. Nous discutons également de l'équation intégrale de frontière conventionnelle et hyper-singulière pour traiter les artefacts numériques liés aux fréquences fictives, lorsque l'on résout des problèmes extérieurs. Nous présentons par la suite un bref aperçu historique et technique du formalisme multipolaire rapide et des outils mathématiques requis pour représenter la solution élémentaire de l'équation de Helmholtz. Nous décrivons les principales étapes, d'un point de vue numérique, du calcul multipolaire. Un problème de propagation sonore dans un quartier, composé de 5 bâtiments, nous a permis de mettre en évidence des problèmes d'instabilités dans le calcul par récursion des matrices de translations, se traduisant par des discontinuités sur le champs de pression de surface et une non convergence du solveur. Ceci nous a conduits à considérer le travail très récent de Gumerov et Duraiswamy en lien avec un processus récursif stable pour le calcul des coefficients des matrices de rotation. Cette version améliorée a ensuite été testée avec succès sur un cas de multi diffraction jusqu'à une taille dimensionnelle de problème de 207 longueur d'ondes. Nous effectuons finalement une comparaison entre un algorithme d'élément de frontière, Micado3D, un algorithme multipolaire et un algorithme basé sur le tir de rayons, Icare, pour le calcul de niveaux de pression moyennés dans une cour ouverte et fermée. L'algorithme multipolaire permet de valider les résultats obtenus par tir de rayons dans la cour ouverte jusqu'à 300 Hz (i.e. 100 longueur d'ondes), tandis que concernant la cour fermée, zone très sensible par l'absence de contribution directes ou réfléchies, des études complémentaires sur le préconditionnement de la matrice semblent requises afin de s'assurer de la pertinence des résultats obtenus à l'aide de solveurs itératifs
Described as one of the best ten algorithms of the 20th century, the fast multipole formalism applied to the boundary element method allows to handle large problems which were inconceivable only a few years ago. Thus, the motivation of the present work is to assess the ability, as well as the benefits in term of computational resources provided by the application of this formalism to the boundary element method, for solving sound propagation problems and providing reference solutions, in three dimensional dense urban environments, in the aim of assessing or improving fast engineering tools. We first introduce the mathematical background required for the derivation of the boundary integral equation, for solving sound propagation problems in unbounded domains. We discuss the conventional and hyper-singular boundary integral equation to overcome the numerical artifact of fictitious eigen-frequencies, when solving exterior problems. We then make a brief historical and technical overview of the fast multipole principle and introduce the mathematical tools required to expand the elementary solution of the Helmholtz equation and describe the main steps, from a numerical viewpoint, of fast multipole calculations. A sound propagation problem in a city block made of 5 buildings allows us to highlight instabilities in the recursive computation of translation matrices, resulting in discontinuities of the surface pressure and a no convergence of the iterative solver. This observation leads us to consider the very recent work of Gumerov & Duraiswamy, related to a ``stable'' recursive computation of rotation matrices coefficients in the RCR decomposition. This new improved algorithm has been subsequently assessed successfully on a multi scattering problem up to a dimensionless domain size equal to 207 wavelengths. We finally performed comparisons between a BEM algorithm, extit{Micado3D}, the FMBEM algorithm and a ray tracing algorithm, Icare, for the calculation of averaged pressure levels in an opened and closed court yards. The fast multipole algorithm allowed to validate the results computed with Icare in the opened court yard up to 300 Hz corresponding, (i.e. 100 wavelengths), while in the closed court yard, a very sensitive area without direct or reflective fields, further investigations related to the preconditioning seem required to ensure reliable solutions provided by iterative solver based algorithms

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Defreville, Boris. "CARACTÉRISATION DE LA QUALITÉ SONORE DE L'ENVIRONNEMENT URBAIN : UNE APPROCHE PHYSIQUE ET PERCEPTIVE BASÉE SUR L'IDENTIFICATION DES SOURCES SONORES." Phd thesis, Université de Cergy Pontoise, 2005. http://tel.archives-ouvertes.fr/tel-00011453.

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Le bruit dans nos villes est perçu comme une question de qualité de vie. Il est généralement évalué par la mesure de son niveau sonore. Si cette mesure est représentative d'environnements bruyants caractérisés par des flots continus de véhicules, elle s'avère insuffisante pour caractériser la « couleur » d'une ambiance sonore où différentes sources coexistent. C'est ainsi que la présente étude se propose d'examiner la qualité d'ambiances sonores urbaine du point de vue de leur composition, c'est-à-dire des sources sonores occurrentes., la finalité étant la mise au point d'une méthode d'évaluation automatique d'un environnement sonore urbain.
La première partie met en évidence le fait que celles-ci ne sont pas toutes perçues de la même manière et qu'en conséquence leurs évaluations métrologiques doivent être adaptées. Ce travail permet de proposer un indicateur lié au désagrément sonore ; en fonction du lieu, cet indicateur utilise la force sonore de la séquence, mais il prend toujours en compte les caractéristiques des différentes sources émergentes.
La deuxième partie de l'étude propose deux méthodes pour la mesure automatique de cet indicateur à travers l'identification des sources. Ces outils représentent, in fine, une aide à la gestion d'un environnement sonore de quartier.

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Dissertations / Theses on the topic 'Urban Acoustics'

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