Submitted by Marcio Emanuel Paixão Santos (marcio.santos@ucsal.br) on 2018-05-04T20:56:14Z No. of bitstreams: 2 DISSERTACAOFRANCISCOGUIMARAES.docx: 2450268 bytes, checksum: bae026f7f497d1377ce648b34ca273b6 (MD5) DISSERTACAOFRANCISCOGUIMARAES.pdf: 1513020 bytes, checksum: 5e830a7d625f9e4969048192a6f90e85 (MD5) / Approved for entry into archive by Rosemary Magalhães (rosemary.magalhaes@ucsal.br) on 2018-05-08T14:30:15Z (GMT) No. of bitstreams: 2 DISSERTACAOFRANCISCOGUIMARAES.docx: 2450268 bytes, checksum: bae026f7f497d1377ce648b34ca273b6 (MD5) DISSERTACAOFRANCISCOGUIMARAES.pdf: 1513020 bytes, checksum: 5e830a7d625f9e4969048192a6f90e85 (MD5) / Made available in DSpace on 2018-05-08T14:30:15Z (GMT). No. of bitstreams: 2 DISSERTACAOFRANCISCOGUIMARAES.docx: 2450268 bytes, checksum: bae026f7f497d1377ce648b34ca273b6 (MD5) DISSERTACAOFRANCISCOGUIMARAES.pdf: 1513020 bytes, checksum: 5e830a7d625f9e4969048192a6f90e85 (MD5) Previous issue date: 2017-12-21 / 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.

<div> The Unmanned Aerial Vehicles (UAV) technology has evolved exponentially in recent years. Smaller and less expensive devices allow a world of new applications in different areas, but as this progress can be beneficial, the use of UAVs with malicious intentions also poses a threat. UAVs can carry weapons or explosives and access restricted zones passing undetected, representing a real threat for civilians and institutions. Acoustic detection in combination with machine learning models emerges as a viable solution since, despite its limitations related with environmental noise, it has provided promising results on classifying UAV sounds, it is adaptable to multiple environments, and especially, it can be a cost-effective solution, something much needed in the counter UAV market with high projections for the coming years. The problem addressed by this project is the need for a real-world adaptable solution which can show that an array of acoustic sensors can be implemented for the detection and localization of UAVs with minimal cost and competitive performance.<br><br></div><div> In this research, a low-cost acoustic detection system that can detect, in real time, about the presence and direction of arrival of a UAV approaching a target was engineered and validated. The model developed includes an array of acoustic sensors remotely connected to a central server, which uses the sound signals to estimate the direction of arrival of the UAV. This model works with a single microphone per node which calculates the position based on the acoustic intensity change produced by the UAV, reducing the implementation costs and being able to work asynchronously. The development of the project included collecting data from UAVs flying both indoors and outdoors, and a performance analysis under realistic conditions. <br><br></div><div> The results demonstrated that the solution provides real time UAV detection and localization information to protect a target from an attacking UAV, and that it can be applied in real world scenarios. </div><div><br></div>

<p>  </p> <p>Bats serve important ecological and economic roles in their communities. However, due to anthropogenic land use and human-introduced disease, bat populations in North America are facing unprecedented declines. To better inform conservation efforts for bat species in northeastern Indiana, I studied two aspects of bat ecology: (1) the effects of urbanization and agriculture on bat community composition in northeastern Indiana and (2) the roosting behavior of a population of state endangered/federally threatened northern long-eared bats (<em>Myotis septentrionalis</em>; hereafter northern myotis) in a restored mesic forest adjacent to a moderately sized city (Fort Wayne, IN). To study the first aspect, I deployed acoustic detectors in green spaces throughout Fort Wayne and the surrounding rural areas of Allen County. For each detector site, I compared species occupancy rates with site-specific characteristics at the plot scale (e.g., % canopy cover, midstory density) and at multiple landscape scales (e.g., % impervious cover within 1 km). Across 429 survey nights, acoustic detectors recorded calls from eight unique bat species, of which six species were abundant enough to conduct occupancy modeling. In four of the six species, measures of the amount of forest and forest edge in the landscape were included in one or more of the top models. The top models for the two other bat species, tricolored bats (<em>Perimyotis subflavus</em>) and silver-haired bats (<em>Lasionycteris noctivagans</em>), included measures of urban land cover and revealed a negative relationship between probability of occupancy and the proportion of high-density urban land in the area. The effect of habitat scale also differed between species. For example, models in the confidence set for eastern red bats (<em>Lasiurus borealis</em>) included variables associated with the plots surrounding detectors and with landscape features within 100 m of detectors. In contrast, the top models for hoary bats (<em>Lasiurus cinereus</em>) included landscape features at larger scales, within 500m and 1 km of detector sites. These findings suggest that both generalist and forest-obligate bat species in this study area selected spaces with greater levels of forested habitat. Furthermore, heavily urbanized areas were less likely to support the same levels of bat diversity as areas with forests and other green space.</p> <p>To accomplish the second aspect of my project, I captured bats in Fox Island County Park (Fort Wayne, IN) using mist-nets and affixed temperature-sensitive radio transmitters to four northern myotis individuals. I tracked these individuals back to day roosts, where I recorded roost characteristics (e.g., tree height, # of roost trees within 0.1 ha) and monitored bat skin temperatures (Tsk). I compared the characteristics of selected roosts to those of randomly assigned available trees in the same landscape to determine trends in roost selection preferences. Northern myotis in this study strongly preferred standing dead trees within a 31-ha patch of flooded forest on the northern border of Fox Island. These trees were highly exposed to solar radiation and were consistently warmer than ambient weather conditions, which suggests they may provide important thermoregulatory benefits to reproductive females and other members of the population.</p> <p>My research offers valuable information regarding resource use by bat communities in a landscape dominated by anthropogenic development. Urban areas containing large stretches of forests with trees in various stages of decay will be more likely to meet the needs of bats that would otherwise struggle in developed landscapes. The results of this study can be used to inform conservation efforts aimed at protecting populations of bats throughout Indiana and the Midwestern United States.</p>

Insulation in rotating machines is a common cause for failure. Therefore, research in the area is large and is important to further increase the knowledge of the phenomena related to insulation degradation. This thesis is a case study on 20 stator bars obtained from a generator that had been showing signs of insulation degradation while in operation. The insulation was investigated using a range of measurements to be able to evaluate the degradation of these bars. The measurements performed were electrical partial discharge measurements, acoustic partial discharge measurements, dielectric response measurements, and breakdown testing. Furthermore, a more scientific approach to the commonly used tap test in the industry was conducted, which has not been done before and the purpose was to validate this commonly used test method. It was concluded that the bars have a significant amount of partial discharges within them, and that the stress grading is likely to be blamed in many of the worst cases. Furthermore, the dielectric response measurements provided good information on the thermal stability of the insulation. The set-up of the tap test did not provide reasonable results, and the method approach as well as the experimental set-up was to blame for this. In future work, investigating this specific area could be beneficial. The electrical partial discharge measurements and the breakdown test provided unexpected results when compared, where the former indicated much degradation while the latter proved that the bars can withstand very high voltage levels. / Isolering i roterande maskiner är en vanlig orsak till fel. Forskningen på området är därför omfattande och viktig för att ytterligare öka kunskapen om fenomen som rör isoleringsnedbrytning. Denna avhandling är en fallstudie på 20 statorstänger som erhållits från en generator som hade visat tecken på isoleringsnedbrytning under drift. Isoleringen undersöktes med hjälp av en rad olika mätningar för att kunna utvärdera nedbrytningen av dessa stänger. De mätningar som utfördes var mätningar av elektriska partiella urladdningar, akustiska partiella urladdningar, mätningar av dielektrisk respons och genombrottstester. Dessutom genomfördes ett mer vetenskapligt tillvägagångssätt för det allmänt använda tapptestet i branschen, vilket inte har gjorts tidigare och syftet var att validera denna allmänt använda testmetod. Slutsatsen blev att stängerna har en betydande mängd partiella urladdningar i sig, och att spänningsgraderingen sannolikt får skulden i många av de värsta fallen. Dessutom gav mätningarna av den dielektriska responsen god information om isoleringens termiska stabilitet. Upplägget för tapptestet gav inte rimliga resultat, och detta berodde både på metodiken och på försöksupplägget. I framtida arbete kan det vara bra att undersöka detta specifika område. Mätningarna av den elektriska partiella urladdningen och genombrottstestet gav oväntade resultat när de jämfördes, där de förstnämnda visade på mycket försämring medan de sistnämnda bevisade att stängerna kan motstå mycket höga spänningsnivåer.