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Publication in the conference proceedings of EUSIPCO, Tampere, Finland, 2000

Submitted by Boris Flegr (boris@uerj.br) on 2021-01-07T14:44:46Z No. of bitstreams: 2 Tese_Lis Bittencourt Vilas Boas correcao biblioteca 050819 - revisado-1-60.pdf: 2920438 bytes, checksum: dd9cf58a7ca0dd9e251202c2dce2061b (MD5) Tese_Lis Bittencourt Vilas Boas correcao biblioteca 050819 - revisado-61-152.pdf: 2774695 bytes, checksum: 7073271c65373184e7e5b3cdf656a83f (MD5) Made available in DSpace on 2021-01-07T14:44:46Z (GMT). No. of bitstreams: 2 Tese_Lis Bittencourt Vilas Boas correcao biblioteca 050819 - revisado-1-60.pdf: 2920438 bytes, checksum: dd9cf58a7ca0dd9e251202c2dce2061b (MD5) Tese_Lis Bittencourt Vilas Boas correcao biblioteca 050819 - revisado-61-152.pdf: 2774695 bytes, checksum: 7073271c65373184e7e5b3cdf656a83f (MD5) Previous issue date: 2019-07-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior The soundscape is the set of all types of sounds present in a certain environment. An acoustic approach involving varied acoustic metrics has not yet been applied to the study of the acoustic environment on the coast of Rio de Janeiro. The present work aims to fill this gap in the knowledge of the coastal region of Rio de Janeiro under both a temporal and a spatial aspect. The first chapter presents a temporal approach, in which an autonomous acoustic recorder was deployed at a depth of 20 m. The programmed daily recording cycle was of 30-minute recordings at 15-minute intervals with a 96 kHz sample rate. Analyses of sound pressure levels, acoustic complexity, automatic detection of biological signals and AIS vessel registrations were performed. Sounds from different sources contributed to the local soundscape, with sounds of artificial origin and biological origin. Daylight hours presented higher sound pressure values in the frequency bands between 25 and 63 Hz and in the frequency bands between 794 and 39 810 Hz (MW, p

Submitted by Daniele Fonseca (daniele@ct.ufrj.br) on 2020-07-17T12:33:25Z No. of bitstreams: 1 VicenteBarrosoJunior-min.pdf: 7803988 bytes, checksum: 4a1f871092032aba931cede6c6724c70 (MD5) Made available in DSpace on 2020-07-17T12:33:25Z (GMT). No. of bitstreams: 1 VicenteBarrosoJunior-min.pdf: 7803988 bytes, checksum: 4a1f871092032aba931cede6c6724c70 (MD5) Previous issue date: 2018-03 A localização de fontes acústicas no mar, desde longa data, tem sido um dos principais temas motivadores das pesquisas na área de acústica submarina. O acelerado crescimento tecnológico alcançado nos dias de hoje, aliado ao notável aumento da capacidade computacional, tem permitido o desenvolvimento de novos métodos para solução de muitos dos clássicos problemas inversos em acústica submarina. Apresenta-se, nesta tese, uma metodologia para localização tridimensional de fontes em águas rasas, com emprego de recentes modelos acústicos tridimensionais, combinado com tradicionais técnicas de Processamento por Campo Casado. Propõ-se tirar proveito da quebra da simetria azimutal do ambiente, decorrente das variações batimétricas, a fim de se conhecer a terceira dimensão do problema - a direção da fonte. A performance da metodologia proposta é avaliada por meio de dados experimentais coletados sobre um único arranjo vertical de hidrofones, em uma região no mar ao norte da ilha de Elba, no litoral oeste da Itália. Os resultados obtidos indicam ser possível localizar uma fonte estática de banda estreita, em termos de distância, profundidade e marcação, dentro de uma margem de erro considerada plenamente aceitável, superando todos os resultados, disponíveis na literatura, sobre localizações pretéritas, realizadas por meio de modelos bidimensionais e com uso do mesmo conjunto de dados experimentais aqui empregados The source acoustic localization at sea, since a long time, has been one of the main motivating themes of research in underwater acoustics. Nowadays, the fast technological advancements achieved together with the remarkable increase in computational power have allowed the development of new methods for solving many of the classic inverse problems in underwater acoustics. In this thesis, we present a method for three-dimensional shallow water source localization, using recent threedimensional acoustic models combined with traditional Matched-Field Processing techniques. The breaking of azimuthal symmetry due to variations in environmental bathymetry is proposed as a mean to determine the bearing of the acoustic source in three dimensions. The performance of the proposed methodology is evaluated with experimental data collected on a single vertical line array in North of the Elba island, off the Italian west coast. The obtained results show that it is possible to locate a stationary narrow-band source in terms of distance, depth and bearing within fully acceptable errors, overcoming all the previous results available in the literature regarding source localization with two-dimensional models and based on the acoustic data set here considered.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-09-13T17:59:09Z No. of bitstreams: 1 2017 - Thamires de Mello Neto.pdf: 1516929 bytes, checksum: faa5edbe5a008b3c926c4e55309ad3e2 (MD5) Made available in DSpace on 2018-09-13T17:59:09Z (GMT). No. of bitstreams: 1 2017 - Thamires de Mello Neto.pdf: 1516929 bytes, checksum: faa5edbe5a008b3c926c4e55309ad3e2 (MD5) Previous issue date: 2017-08-24 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior Throughout the coastal habitats, the Guiana dolphin is affected by anthropogenic actions that threaten its conservation, especially fishing and boat traffic. Sepetiba bay seems to offer a high-quality habitat, because the dolphins are very abundant and found in the area all year round. With the industrial development in Sepetiba Bay, there will be an increase of large vessels flow, which will carry several types of cargo, some of which are harmful to the environment and directly dangerous to the animals. This intense traffic occurs in a place used by dolphins for feeding, foraging and breeding, may generate negative behavioral responses, changing their affinity for the place and move away. From a landbase, during the period of one year (July 2015 to August 2016), sightings were realized with the objective of evaluating whether the different vessels generate impacts on the Guiana dolphins? behavior. The evaluation was based on a behavioral reaction classification in Negative, Neutral, and Positive, in interactions with a 500m maximum distance among the study objects. The study had a total of 288 h of sample effort, whereupon with the most interactions were Jan/16 with 14.90% (n = 11), Jul/15 with 13.51% (n = 10) and Mar/16 and Apr/16 with 12.16% (n = 9). Interactions occurred mostly during the period from 10 h to 11 h AM (32.43%), 9h to 10h AM (24.32%), and 11 to 12 h AM (24.32%), and all occurred outside the dredged chanel. The dolphin groups, in general, were small. The presence of calves accompanying the group was also low, only 12 individuals (6.86%). The vessels that most interacted with the dolphins were: Boats (79.73%) and Trawlers (18.92%), and only one ship (1.35%) was observed interacting with the animals. Foraging (57.30%) and Travelling (42.70%) were the most performed activities. The most expressive behavioral reactions were Neutral (71.43%), followed by Negative (24%), and very low occurrence of Positive reactions (4.28%). In order to verify if there were significant differences between the vessels and behavioral reactions, X2 was used, assuming pvalue